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Khanmohammadi S, Kushnir Friedman K, Chen E, Kastuar SM, Ekuma CE, Koski KJ, Titova LV. Tailoring Ultrafast Near-Band Gap Photoconductive Response in GeS by Zero-Valent Cu Intercalation. ACS Appl Mater Interfaces 2024; 16:16445-16452. [PMID: 38528798 DOI: 10.1021/acsami.3c19251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Zero-valent intercalation of atomic metals into the van der Waals gap of layered materials can be used to tune their electronic, optical, thermal, and mechanical properties. Here, we report the impact of intercalating ∼3 atm percent of zero-valent copper into germanium sulfide (GeS). Advanced many-body calculations predict that copper introduces quasi-localized intermediate band states, and time-resolved THz spectroscopy studies demonstrate that those states have prominent effects on the photoconductivity of GeS. Cu-intercalated GeS exhibits a faster rise of transient photoconductivity and a shorter lifetime of optically injected carriers following near-gap excitation with 800 nm pulses. At the same time, Cu intercalation improves free carrier mobility from 1100 to 1300 cm2 V-1 s-1, which we attribute to the damping of acoustic phonons observed in Brillouin scattering and consequent reduction of phonon scattering.
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Affiliation(s)
- Sepideh Khanmohammadi
- Department of Physics, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
| | - Kateryna Kushnir Friedman
- Department of Physics, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
| | - Ethan Chen
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Srihari M Kastuar
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Chinedu E Ekuma
- Department of Physics, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Kristie J Koski
- Department of Chemistry, University of California Davis, Davis, California 95616, United States
| | - Lyubov V Titova
- Department of Physics, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
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2
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Shen C, Zhang F, Sasaki T, Eerdun C, Hayashi M, Wang HW, Tominaga K, Mutailipu M, Pan S. Where do the Fluorine Atoms Go in Inorganic-Oxide Fluorinations? A Fluorooxoborate Illustration under Terahertz Light. Angew Chem Int Ed Engl 2024; 63:e202319121. [PMID: 38344870 DOI: 10.1002/anie.202319121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Indexed: 03/01/2024]
Abstract
The substitution of fluorine atoms for oxygen atoms/hydroxyl groups has emerged as a promising strategy to enhance the physical and chemical properties of oxides/hydroxides in fluorine chemistry. However, distinguishing fluorine from oxygen/hydroxyl in the reaction products poses a significant challenge in existing characterization methods. In this study, we illustrate that terahertz (THz) spectroscopy provides a powerful tool for addressing this challenge. To this end, we investigated two fluorination reactions of boric acid, utilizing MHF2 (M=Na, C(NH2)3) as fluorine reagents. Through an interplay between THz spectroscopy and solid-state density functional theory, we have conclusively demonstrated that fluorine atoms exclusively bind with the sp3-boron but not with the sp2-boron in the reaction products of Na[B(OH)3][B3O3F2(OH)2] (NaBOFH) and [C(NH2)3]2B3O3F4OH (GBF2). Based on this evidence, we have proposed a reaction pathway for the fluorinations under investigation, a process previously hindered due to structural ambiguity. This work represents a step forward in gaining a deeper understanding of the precise structures and reaction mechanisms involved in the fluorination of oxides/hydroxides, illuminated by the insights provided by THz spectroscopy.
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Affiliation(s)
- Chunjie Shen
- Research Center for Crystal Materials, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China
- Institution Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Feng Zhang
- Research Center for Crystal Materials, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China
- Institution Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Tetsuo Sasaki
- Research Institute of Electronics, Shizuoka University, Hamamatsu, Shizuoka, 432-8011, Japan
| | - Chaolu Eerdun
- Department of Pharmaceutical Sciences, Inner Mongolia Medical University, Jinshan Economic & Technology Development District, Hohhot, Inner Mongolia, 010110, China
| | - Michitoshi Hayashi
- Center for Condensed Matter Sciences, National Taiwan University, 1 Roosevelt Rd., Sec. 4, Taipei, 10617, Taiwan
| | - Houng-Wei Wang
- Center for Condensed Matter Sciences, National Taiwan University, 1 Roosevelt Rd., Sec. 4, Taipei, 10617, Taiwan
| | - Keisuke Tominaga
- Molecular Photoscience Research Center, Kobe University, Nada, Kobe, 657-8501, Japan
| | - Miriding Mutailipu
- Research Center for Crystal Materials, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China
- Institution Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shilie Pan
- Research Center for Crystal Materials, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China
- Institution Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
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3
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Chen S, Al-Hilfi SH, Chen G, Zhang H, Zheng W, Virgilio LD, Geuchies JJ, Wang J, Feng X, Riedinger A, Bonn M, Wang HI. Tuning the Inter-Nanoplatelet Distance and Coupling Strength by Thermally Induced Ligand Decomposition. Small 2024; 20:e2308951. [PMID: 38010120 DOI: 10.1002/smll.202308951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Indexed: 11/29/2023]
Abstract
CdSe nanoplatelets (NPLs) are promising 2D semiconductors for optoelectronic applications, in which efficient charge transport properties are desirable. It is reported that thermal annealing constitutes an effective strategy to control the optical absorption and electrical properties of CdSe NPLs by tuning the inter-NPL distance. Combining optical absorption, transmission electron microscopy, and thermogravimetric analysis, it is revealed that the thermal decomposition of ligands (e.g., cadmium myristate) governs the inter-NPL distance and thus the inter-NPL electronic coupling strength. Employing ultrafast terahertz spectroscopy, it is shown that this enhanced electronic coupling increases both the free carrier generation efficiency and the short-range mobility in NPL solids. The results show a straightforward method of controlling the interfacial electronic coupling strength for developing functional optoelectronic devices through thermal treatments.
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Affiliation(s)
- Shuai Chen
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Samir H Al-Hilfi
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Guangbo Chen
- Center for Advancing Electronics Dresden (cfaed) and Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstr. 4, 01062, Dresden, Germany
| | - Heng Zhang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Wenhao Zheng
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Lucia Di Virgilio
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Jaco J Geuchies
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Junren Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Xinliang Feng
- Center for Advancing Electronics Dresden (cfaed) and Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, Mommsenstr. 4, 01062, Dresden, Germany
- Max Planck Institute of Microstructure Physics, D-06120, Halle (Saale), Germany
| | - Andreas Riedinger
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Hai I Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- Nanophotonics, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, Utrecht, 3584 CC, The Netherlands
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4
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Connelly BC, Taylor PJ, de Coster GJ. Emergence of threefold symmetric helical photocurrents in epitaxial low twinned Bi 2Se 3. Proc Natl Acad Sci U S A 2024; 121:e2307425121. [PMID: 38271339 PMCID: PMC10835140 DOI: 10.1073/pnas.2307425121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/29/2023] [Indexed: 01/27/2024] Open
Abstract
We present evidence of a strong circular photon drag effect (PDE) in topological insulators (TIs) through the observation of helicity-dependent topological photocurrents with threefold rotational symmetry using THz spectroscopy in epitaxially-grown Bi2Se3 with reduced crystallographic twinning. We establish how twinned domains introduce competing nonlinear optical (NLO) responses inherent to the crystal structure that obscure geometry-sensitive optical processes through the introduction of a spurious mirror symmetry. Minimizing the twinning defect reveals strong NLO response currents whose magnitude and direction depend on the alignment of the excitation to the crystal axes and follow the threefold rotational symmetry of the crystal. Notably, photocurrents arising from helical light reverse direction for left/right circular polarizations and maintain a strong azimuthal dependence-a result uniquely attributable to the circular PDE, where the photon momentum acts as an applied in-plane field stationary in the laboratory frame. Our results demonstrate new levels of control over the magnitude and direction of photocurrents in TIs and that the study of single-domain films is crucial to reveal hidden phenomena that couple topological order and crystal symmetries.
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Affiliation(s)
- Blair C. Connelly
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
| | - Patrick J. Taylor
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
| | - George J. de Coster
- U.S. Army Combat Capabilities Development Command Army Research Laboratory, Adelphi, MD20783
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5
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Ge M, Wang Y, Zhang F, Wang Z, Li H, Xu D, Yao J. Study of low-frequency spectroscopic characteristics of γ-aminobutyric acid with THz and low-wavenumber Raman spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc 2024; 305:123550. [PMID: 37864976 DOI: 10.1016/j.saa.2023.123550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/10/2023] [Accepted: 10/15/2023] [Indexed: 10/23/2023]
Abstract
γ-aminobutyric (GABA) is the most important inhibitory neurotransmitier in vertebrate central nervous systems. The content level of GABA is related to the different degree of malignancy gliomas. Thus, it can be considered a promising glioma biomarker. In this paper, the spectroscopic properties of GABA have been characterized by combining the THz spectroscopy with low-wavenumber Raman spectroscopy. The experimental results showed that, GABA exhibited three absorption peaks and three refractive index peaks in the range of 0.6-2.1 THz. The limit of detection can reach up to 0.428 % based on the absorption coefficient at the peak of 2.04 THz. Moreover, the low-wavenumber Raman spectrum of GABA showed seven characteristic peaks at 41.0, 50.8, 58.8, 77.2, 98.8, 115.6, 141.2 cm-1 in 0-150 cm-1 region. Moreover, the THz and low-wavenumber theoretical spectra of GABA were simulated with solid-state density function theory, respectively. The calculated results were in good agreement with the experimental observations. On the basis of calculated result, the vibrational motions of each THz and Raman characteristic modes were quantitatively decomposed by analytical mode-decoupling method, where the contribution percentages of external translation, external librations and intramolecular vibration of each vibration modes were analyzed Furthermore, the low-frequency characteristics of GABA was analyzed by combining the THz and low-wavenumber Raman spectroscopy. It is beneficial for the structural information analysis and quantitative identification of biomarker GABA in early stage diagnosis of glioma.
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Affiliation(s)
- Meilan Ge
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Optoelectronics Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Yuye Wang
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Optoelectronics Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China.
| | - Feng Zhang
- Crystal Materials Research Center, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Xinjiang, 830011, China
| | - Zelong Wang
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Optoelectronics Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Haibin Li
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Optoelectronics Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Degang Xu
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Optoelectronics Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Jianquan Yao
- School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; Key Laboratory of Optoelectronics Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
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Righetto M, Wang Y, Elmestekawy KA, Xia CQ, Johnston MB, Konstantatos G, Herz LM. Cation-Disorder Engineering Promotes Efficient Charge-Carrier Transport in AgBiS 2 Nanocrystal Films. Adv Mater 2023; 35:e2305009. [PMID: 37670455 DOI: 10.1002/adma.202305009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 09/01/2023] [Indexed: 09/07/2023]
Abstract
Efficient charge-carrier transport is critical to the success of emergent semiconductors in photovoltaic applications. So far, disorder has been considered detrimental for charge-carrier transport, lowering mobilities, and causing fast recombination. This work demonstrates that, when properly engineered, cation disorder in a multinary chalcogenide semiconductor can considerably enhance the charge-carrier mobility and extend the charge-carrier lifetime. Here, the properties of AgBiS2 nanocrystals (NCs) are explored as a function of Ag and Bi cation-ordering, which can be modified via thermal-annealing. Local Ag-rich and Bi-rich domains formed during hot-injection synthesis are transformed to induce homogeneous disorder (random Ag-Bi distribution). Such cation-disorder engineering results in a sixfold increase in the charge-carrier mobility, reaching ≈2.7 cm2 V-1 s-1 in AgBiS2 NC thin films. It is further demonstrated that homogeneous cation disorder reduces charge-carrier localization, a hallmark of charge-carrier transport recently observed in silver-bismuth semiconductors. This work proposes that cation-disorder engineering flattens the disordered electronic landscape, removing tail states that would otherwise exacerbate Anderson localization of small polaronic states. Together, these findings unravel how cation-disorder engineering in multinary semiconductors can enhance the efficiency of renewable energy applications.
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Affiliation(s)
- Marcello Righetto
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Yongjie Wang
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860, Barcelona, Spain
| | - Karim A Elmestekawy
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Chelsea Q Xia
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Michael B Johnston
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Gerasimos Konstantatos
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, 08860, Barcelona, Spain
- ICREA-Institució Catalana de Recerca i Estudia Avançats, Lluis Companys 23, Barcelona, 08010, Spain
| | - Laura M Herz
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
- Institute for Advanced Study, Technical University of Munich, Lichtenbergstrasse 2a, D-85748, Garching, Germany
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7
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Penkov NV. Terahertz spectroscopy as a method for investigation of hydration shells of biomolecules. Biophys Rev 2023; 15:833-849. [PMID: 37974994 PMCID: PMC10643733 DOI: 10.1007/s12551-023-01131-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 08/30/2023] [Indexed: 11/19/2023] Open
Abstract
The hydration of biomolecules is one of the fundamental processes underlying the construction of living matter. The formation of the native conformation of most biomolecules is possible only in an aqueous environment. At the same time, not only water affects the structure of biomolecules, but also biomolecules affect the structure of water, forming hydration shells. However, the study of the structure of biomolecules is given much more attention than their hydration shells. A real breakthrough in the study of hydration occurred with the development of the THz spectroscopy method, which showed that the hydration shell of biomolecules is not limited to 1-2 layers of strongly bound water, but also includes more distant areas of hydration with altered molecular dynamics. This review examines the fundamental features of the THz frequency range as a source of information about the structural and dynamic characteristics of water that change during hydration. The applied approaches to the study of hydration shells of biomolecules based on THz spectroscopy are described. The data on the hydration of biomolecules of all main types obtained from the beginning of the application of THz spectroscopy to the present are summarized. The emphasis is placed on the possible participation of extended hydration shells in the realization of the biological functions of biomolecules and at the same time on the insufficient knowledge of their structural and dynamic characteristics.
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Affiliation(s)
- Nikita V. Penkov
- Federal Research Center “Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences”, Institute of Cell Biophysics RAS, 142290 Pushchino, Russia
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8
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Kononov LO, Fukase K, Bunkin NF. Editorial: Chemical reactivity and solution structure. Front Chem 2023; 11:1293697. [PMID: 37822774 PMCID: PMC10562685 DOI: 10.3389/fchem.2023.1293697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Affiliation(s)
- Leonid O Kononov
- Laboratory of GlycoChemistry, N. D. Zelinsky Institute of Organic Chemistry, Moscow, Russia
| | - Koichi Fukase
- Department of Chemistry, Osaka University, Osaka, Japan
| | - Nikolai F Bunkin
- Department of Fundamental Sciences, Bauman Moscow State Technical University, Moscow, Russia
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9
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Bratu AM, Bojan M, Banita S, Petrus M, Popa C. NIR and THz spectroscopy: An experimental investigation toward nicotine-related devices. J Biophotonics 2023; 16:e202300120. [PMID: 37260323 DOI: 10.1002/jbio.202300120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/15/2023] [Accepted: 05/24/2023] [Indexed: 06/02/2023]
Abstract
This study examined the content of nicotine-delivery products using terahertz time-domain spectroscopy (THz-TDS) and breath ethylene investigated with CO2 laser photoacoustic spectroscopy (CO2 LPAS) system as a biomarker of oxidative stress after smoking. The THz-TDS method provided valuable information on the transmission spectra of tobacco and nicotine in smoking products. From the CO2 LPAS data it was observed that in cigarette (TC) smoking the mean breath ethylene was 687 parts per billion (ppb), while in electronic cigarettes and tobacco heating devices smoking the mean ethylene was 56 ppb and 48 ppb, respectively. The main finding was that TC showed higher transmission in the THz region producing a higher oxidative stress on the body.
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Affiliation(s)
- Ana-Maria Bratu
- National Institute for Laser, Plasma and Radiation Physics, Bucharest, PO, Romania
| | - Mihaela Bojan
- National Institute for Laser, Plasma and Radiation Physics, Bucharest, PO, Romania
| | - Stefan Banita
- National Institute for Laser, Plasma and Radiation Physics, Bucharest, PO, Romania
| | - Mioara Petrus
- National Institute for Laser, Plasma and Radiation Physics, Bucharest, PO, Romania
| | - Cristina Popa
- National Institute for Laser, Plasma and Radiation Physics, Bucharest, PO, Romania
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10
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Bian Y, Zhu Z, Zhang X, Zeng R, Yang B. Terahertz spectroscopy for quantitatively elucidating the crystal transformation of chiral histidine enantiomers to racemic compounds. Food Chem 2023; 406:135043. [PMID: 36450194 DOI: 10.1016/j.foodchem.2022.135043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/04/2022] [Accepted: 11/20/2022] [Indexed: 11/26/2022]
Abstract
d-Histidine (d-His), l-Histidine (l-His), and their racemic compound dl-Histidine (dl-His) have different stereo chirality, making them intrinsic diverse functionalities to the living system. Identifying the configuration and crystal structures of enantiomers and the racemic compound is always the foremost requirement in processing protein foods. Although these features can be analyzed by spectroscopic technologies individually, it remains challenging to incorporate these complex methods into a facile analytical strategy. Herein, we propose a terahertz spectroscopy with solid-state density functional theory to both distinguish the configurational difference and quantify the crystal transformation from l-His and d-His to dl-His. By comparison with X-ray diffraction analysis, the validity of the crystal transformation evaluation based on terahertz spectroscopy is verified. A normalized fitting line regarding the terahertz absorption frequency and intensity is calculated to quantitatively elucidate the crystal transformation from enantiomers to dl-His. Our findings provide a new analytical approach to the research on food chemistry.
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Chowdhury MAZ, Rice TE, Oehlschlaeger MA. TSMC-Net: Deep-Learning Multigas Classification Using THz Absorption Spectra. ACS Sens 2023; 8:1230-1240. [PMID: 36815833 DOI: 10.1021/acssensors.2c02615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
The identification of gas mixture speciation from a complex multicomponent absorption spectrum is a problem in gas sensing that can be addressed using machine-learning approaches. Here, we report on a deep convolutional neural network for multigas classification using terahertz (THz) absorption spectra, THz spectra mixture classifier network or TSMC-Net. TSMC-Net has been developed to identify eight volatile organic compounds in mixtures based on their fingerprint rotational absorption spectra in the 220-330 GHz frequency range. A data set consisting of simulated absorption spectra for randomly generated mixtures, with absorption greater than thresholds representing detectable limits and annotated with multiple labels, was prepared for model development. The supervised multilabel classification problem, i.e., the identification of individual gases in a mixture, is converted to a supervised multiclass classification problem via label powerset conversion. The trained model is validated and tested against simulated spectra for gas mixtures, with and without white Gaussian noise. The trained model exhibits high precision, recall, and accuracy for each pure compound. Class activation maps illustrate the complex decision-making process of the model and highlight relevant frequency regions that are needed to identify unique mixtures. Finally, the model was demonstrated against measured THz absorption spectra for pure species and mixtures, acquired using a microelectronics-based THz absorption spectrometer. The data set generation strategy and deep convolutional neural network approach are generalized and can be extrapolated to other spectroscopy types, frequency ranges, and sensors.
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Affiliation(s)
- M Arshad Zahangir Chowdhury
- Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3522, United States
| | - Timothy E Rice
- Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3522, United States
| | - Matthew A Oehlschlaeger
- Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3522, United States
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12
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Izadi S, Bhattacharya A, Salloum S, Han JW, Schnatmann L, Wolff U, Perez N, Bendt G, Ennen I, Hütten A, Nielsch K, Schulz S, Mittendorff M, Schierning G. Density-Dependence of Surface Transport in Tellurium-Enriched Nanograined Bulk Bi 2 Te 3. Small 2023; 19:e2204850. [PMID: 36642858 DOI: 10.1002/smll.202204850] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Three-dimensional topological insulators (3D TI) exhibit conventional parabolic bulk bands and protected Dirac surface states. A thorough investigation of the different transport channels provided by the bulk and surface carriers using macroscopic samples may provide a path toward accessing superior surface transport properties. Bi2 Te3 materials make promising 3D TI models; however, due to their complicated defect chemistry, these materials have a high number of charge carriers in the bulk that dominate the transport, even as nanograined structures. To partially control the bulk charge carrier density, herein the synthesis of Te-enriched Bi2 Te3 nanoparticles is reported. The resulting nanoparticles are compacted into nanograined pellets of varying porosity to tailor the surface-to-volume ratio, thereby emphasizing the surface transport channels. The nanograined pellets are characterized by a combination of resistivity, Hall- and magneto-conductance measurements together with (THz) time-domain reflectivity measurements. Using the Hikami-Larkin-Nagaoka (HLN) model, a characteristic coherence length of ≈200 nm is reported that is considerably larger than the diameter of the nanograins. The different contributions from the bulk and surface carriers are disentangled by THz spectroscopy, thus emphasizing the dominant role of the surface carriers. The results strongly suggest that the surface transport carriers have overcome the hindrance imposed by nanoparticle boundaries.
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Affiliation(s)
- Sepideh Izadi
- Department of Physics, Bielefeld University, 33615, Bielefeld, Germany
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Ahana Bhattacharya
- Department of Physics, University of Duisburg-Essen, 47057, Duisburg, Germany
| | - Sarah Salloum
- Department of Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
| | - Jeong Woo Han
- Department of Physics, University of Duisburg-Essen, 47057, Duisburg, Germany
| | | | - Ulrike Wolff
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Nicolas Perez
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Georg Bendt
- Department of Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
| | - Inga Ennen
- Department of Physics, Bielefeld University, 33615, Bielefeld, Germany
| | - Andreas Hütten
- Department of Physics, Bielefeld University, 33615, Bielefeld, Germany
| | - Kornelius Nielsch
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Stephan Schulz
- Department of Chemistry, University of Duisburg-Essen, 45141, Essen, Germany
- Center for Nanointegration Duisburg-Essen (Cenide), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057, Duisburg, Germany
| | - Martin Mittendorff
- Department of Physics, University of Duisburg-Essen, 47057, Duisburg, Germany
| | - Gabi Schierning
- Department of Physics, Bielefeld University, 33615, Bielefeld, Germany
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13
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Tyree DJ, Brothers MC, Sim D, Flory L, Tomb M, Strayer K, Jung A, Lee J, Land C, Guess B, Chancellor C, Zelasko J, Alvarado RL, Pitsch RL, Harshman SW, Regn D, Medvedev IR, Kim SS. Detection of Asthma Inhaler Use via Terahertz Spectroscopy. ACS Sens 2023; 8:610-618. [PMID: 36657059 DOI: 10.1021/acssensors.2c01795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Inhaled medications are commonplace for administering bronchodilators, anticholinergics, and corticosteroids. While they have a defined legitimate use, they are also used in sporting events as performance-enhancing drugs. These performance enhancers can be acquired via both legal (i.e., at a pharmacy through over-the-counter medications or through a prescription) and illicit (i.e., black market and foreign pharmacies) means, thus making monitoring procurement impossible. While urine tests can detect these pharmacological agents hours after they have been inhaled, there is a significant lag time before they are observed in urine. Direct detection of these inhaled agents is complicated and requires a multiplexed approach due to the sheer number of inhaled pharmacological agents. Therefore, detection of propellants, which carry the drug into the lungs, provides a simpler path forward toward detection of broad pharmacological agents. In this paper, we demonstrate the first use of terahertz spectroscopy (THz) to detect inhaled medications in human subjects. Notably, we were able to detect and quantitate the propellant, HFA-134a, in breath up to 30 min after using an asthma inhaler, enabling the use of a point-of-care device to monitor exhaled breath for the presence of propellants. We also demonstrate via simulations that the same approach can be leveraged to detect and identify next-generation propellants, specifically HFA-152a. As a result, we provide evidence that a single point-of-care THz sensor can detect when individuals have used pressure-mediated dose inhalers (pMDIs) without further modification of the hardware.
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Affiliation(s)
- Daniel J Tyree
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States.,Department of Physics, Wright State University, Dayton, Ohio 45435, United States
| | - Michael C Brothers
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States.,UES Inc. Dayton, Ohio 45432, United States
| | - Daniel Sim
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States.,UES Inc. Dayton, Ohio 45432, United States
| | - Laura Flory
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States.,UES Inc. Dayton, Ohio 45432, United States
| | - Miranda Tomb
- United States Air Force School of Aerospace Medicine, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Kraig Strayer
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States.,UES Inc. Dayton, Ohio 45432, United States
| | - Anne Jung
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States.,UES Inc. Dayton, Ohio 45432, United States
| | - Jaehwan Lee
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Christopher Land
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Barlow Guess
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Cody Chancellor
- United States Air Force School of Aerospace Medicine, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Jeremy Zelasko
- United States Air Force School of Aerospace Medicine, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Rosa Linda Alvarado
- United States Air Force School of Aerospace Medicine, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Rhonda L Pitsch
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Sean W Harshman
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Dara Regn
- United States Air Force School of Aerospace Medicine, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Ivan R Medvedev
- Department of Physics, Wright State University, Dayton, Ohio 45435, United States
| | - Steve S Kim
- 711th Human Performance Wing, Wright Patterson Air Force Base, Dayton, Ohio 45433, United States
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14
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Zhao R, Feng Y, Ling H, Zou X, Wang M, Lu G. Enhanced Terahertz Fingerprint Sensing Mechanism Study of Tiny Molecules Based on Tunable Spoof Surface Plasmon Polaritons on Composite Periodic Groove Structures. Sensors (Basel) 2023; 23:2496. [PMID: 36904706 PMCID: PMC10007521 DOI: 10.3390/s23052496] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
Highly sensitive detection of enhanced terahertz (THz) fingerprint absorption spectrum of trace-amount tiny molecules is essential for biosensing. THz surface plasmon resonance (SPR) sensors based on Otto prism-coupled attenuated total reflection (OPC-ATR) configuration have been recognized as a promising technology in biomedical detection applications. However, THz-SPR sensors based on the traditional OPC-ATR configuration have long been associated with low sensitivity, poor tunability, low refractive index resolution, large sample consumption, and lack of fingerprint analysis. Here, we propose an enhanced tunable high-sensitivity and trace-amount THz-SPR biosensor based on a composite periodic groove structure (CPGS). The elaborate geometric design of the spoof surface plasmon polaritons (SSPPs) metasurface increases the number of electromagnetic hot spots on the surface of the CPGS, improves the near-field enhancement effect of SSPPs, and enhances the interaction between THz wave and the sample. The results show that the sensitivity (S), figure of merit (FOM) and Q-factor (Q) can be increased to 6.55 THz/RIU, 4234.06 1/RIU and 629.28, respectively, when the refractive index range of the sample to measure is between 1 and 1.05 with the resolution 1.54×10-5 RIU. Moreover, by making use of the high structural tunability of CPGS, the best sensitivity (SPR frequency shift) can be obtained when the resonant frequency of the metamaterial approaches the biological molecule oscillation. These advantages make CPGS a strong candidate for the high-sensitivity detection of trace-amount biochemical samples.
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Affiliation(s)
- Ruiqi Zhao
- Shandong Key Laboratory of Low-Altitude Airspace Surveillance Network Technology, QILU Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Jinan 250132, China
| | - Yu Feng
- Shandong Key Laboratory of Low-Altitude Airspace Surveillance Network Technology, QILU Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Jinan 250132, China
| | - Haotian Ling
- Shandong Key Laboratory of Low-Altitude Airspace Surveillance Network Technology, QILU Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Jinan 250132, China
| | - Xudong Zou
- Shandong Key Laboratory of Low-Altitude Airspace Surveillance Network Technology, QILU Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Jinan 250132, China
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute (AIR), Chinese Academy of Sciences (CAS), Beijing 100190, China
| | - Meng Wang
- School of Integrated Circuit Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
| | - Guizhen Lu
- State Key Laboratory of Media Convergence and Communication, Communication University of China (CUC), Beijing 100039, China
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15
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Novelli F, Chen K, Buchmann A, Ockelmann T, Hoberg C, Head-Gordon T, Havenith M. The birth and evolution of solvated electrons in the water. Proc Natl Acad Sci U S A 2023; 120:e2216480120. [PMID: 36791104 DOI: 10.1073/pnas.2216480120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
The photo-induced radiolysis of water is an elementary reaction in biology and chemistry, forming solvated electrons, OH radicals, and hydronium cations on fast time scales. Here, we use an optical-pump terahertz-probe spectroscopy setup to trigger the photoionization of water molecules with optical laser pulses at ~400 nm and then time-resolve the transient solvent response with broadband terahertz (THz) fields with a ~90 fs time resolution. We observe three distinct spectral responses. The first is a positive broadband mode that can be attributed to an initial diffuse, delocalized electron with a radius of (22 ± 1) Å, which is short lived (<200 fs) because the absorption is blue-shifting outside of the THz range. The second emerging spectroscopic signature with a lifetime of about 150 ps is attributed to an intermolecular mode associated with a mass rearrangement of solvent molecules due to charge separation of radicals and hydronium cations. After 0.2 ps, we observe a long-lasting THz signature with depleted intensity at 110 cm-1 that is well reproduced by ab initio molecular dynamics. We interpret this negative band at 110 cm-1 as the solvent cage characterized by a weakening of the hydrogen bond network in the first and second hydration shells of the cavity occupied by the localized electron.
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16
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Aalto S, Battersby C, Chin G, Hunt LK, Rigopoulou D, Stark AA, Viti S, Walker CK. Extragalactic Science with the Orbiting Astronomical Satellite Investigating Stellar Systems (OASIS) Observatory. Space Sci Rev 2023; 219:9. [PMID: 36747508 PMCID: PMC9895007 DOI: 10.1007/s11214-023-00948-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 01/04/2023] [Indexed: 06/18/2023]
Abstract
The Orbiting Astronomical Satellite for Investigating Stellar Systems (OASIS), a proposed Astrophysics MIDEX-class mission concept, has an innovative 14-meter diameter inflatable primary mirror that will provide the sensitivity to study far-infrared continuum and line emission from galaxies at all redshifts with high spectral resolution heterodyne receivers. OASIS will have the sensitivity to follow the water trail from galaxies to the comets that create oceans. It will bring an understanding of the role of water in galaxy evolution and its part of the oxygen budget, by measuring water emission from local to intermediate redshift galaxies, observations that have not been possible from the ground. Observation of the ground-state HD line will accurately measure gas mass in a wide variety of astrophysical objects. Thanks to its exquisite spatial resolution and sensitivity, OASIS will, during its one-year baseline mission, detect water in galaxies with unprecedented statistical significance. This paper reviews the extragalactic science achievable and planned with OASIS.
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Affiliation(s)
- Susanne Aalto
- Department of Space, Earth and Environment, Onsala Space Observatory, Chalmers University of Technology, Onsala, Sweden
| | - Cara Battersby
- Department of Physics, University of Connecticut, Storrs, 06269 CT USA
| | - Gordon Chin
- Planetary Systems Laboratory, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, 20771 MD USA
| | - Leslie K. Hunt
- Istituto Nazionale di Astrofisica-Osservatorio Astrofisico di Arcetri, Firenze, Italy
| | - Dimitra Rigopoulou
- Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU UK
| | - Antony A. Stark
- Center for Astrophysics | Harvard & Smithsonian, 60 Garden St., Cambridge, MA USA
| | - Serena Viti
- Leiden Observatory, P.O. Box 9513, Leiden, The Netherlands
| | - Christopher K. Walker
- Department of Astronomy and Steward Observatory, University of Arizona, Tucson, 85719 AZ USA
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17
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Mihai L, Caruntu G, Rotaru A, Caruntu D, Mykhailovych V, Ciomaga CE, Horchidan N, Stancalie A, Marcu A. GHz-THz Dielectric Properties of Flexible Matrix-Embedded BTO Nanoparticles. Materials (Basel) 2023; 16:1292. [PMID: 36770296 PMCID: PMC9921476 DOI: 10.3390/ma16031292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
BaTiO3 (BTO) nanoparticles produced by wet chemistry methods were embedded in several types of flexible materials in order to fabricate flexible electronic devices. Starting from the produced nanoparticle dielectric properties, flexible material dielectric properties were tested for high electromagnetic frequencies (30 GHz-2 THz) using time domain spectroscopy. Dielectric performances of the different materials obtained with variable nanoparticle concentrations up to 40 wt.%, embedded in, gelatin, epoxy, and styrene-butadiene were compared at several working temperatures between 0 °C and 120 °C. Beside the general trend of ε' decrease with temperature and loses increase with the operating frequency, we were able to identify few matrix dependent optimal nanoparticle concentrations. The best composite performances were achieved by the BTO-SBS matrix, with filler concentration of 2 wt.%, where the losses have been of 1.5%, followed by BTO-gelatin matrix, with filler concentration of 40 wt.%, with higher losses percent of almost 10% for THz frequencies.
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Affiliation(s)
- Laura Mihai
- Center for Advanced Laser Technology, National Institute for Laser Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Gabriel Caruntu
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI 48859, USA
- Department of Electrical Engineering and Computer Science and MANSID Research Center, “Stefan Cel Mare” University, 13 Universitatii St., 720229 Suceava, Romania
| | - Aurelian Rotaru
- Department of Electrical Engineering and Computer Science and MANSID Research Center, “Stefan Cel Mare” University, 13 Universitatii St., 720229 Suceava, Romania
| | - Daniela Caruntu
- Department of Chemistry and Biochemistry, Central Michigan University, 1200 S. Franklin St., Mount Pleasant, MI 48859, USA
- Department of Electrical Engineering and Computer Science and MANSID Research Center, “Stefan Cel Mare” University, 13 Universitatii St., 720229 Suceava, Romania
| | - Vasyl Mykhailovych
- Department of Electrical Engineering and Computer Science and MANSID Research Center, “Stefan Cel Mare” University, 13 Universitatii St., 720229 Suceava, Romania
| | - Cristina Elena Ciomaga
- Department of Exact & Natural Sciences, Institute of Interdisciplinary Research, Al. I. Cuza University of Iasi, 11 Bld. Carol I, 700506 Iasi, Romania
| | - Nadejda Horchidan
- Faculty of Physics, Al. I. Cuza University of Iasi, 11 Bld. Carol I, 700506 Iasi, Romania
| | - Andrei Stancalie
- Center for Advanced Laser Technology, National Institute for Laser Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Aurelian Marcu
- Center for Advanced Laser Technology, National Institute for Laser Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
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18
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Zang Z, Li Z, Wang J, Lu X, Lyu Q, Tang M, Cui HL, Yan S. Terahertz spectroscopic monitoring and analysis of citrus leaf water status under low temperature stress. Plant Physiol Biochem 2023; 194:52-59. [PMID: 36375327 DOI: 10.1016/j.plaphy.2022.10.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/18/2022] [Accepted: 10/31/2022] [Indexed: 06/16/2023]
Abstract
Low temperature stress, in the form of chilling and freezing, is one of the major environmental factors impacting on citrus yield, which changes plant's water state and results in the crops' sub-health or injury. The innovative terahertz (THz) spectroscopy and imaging based sensing technology has been shown to be a suitable tool for plant leaf water status determination, due to THz radiation's innate sensitivity to hydrogen bond vibration in aqueous solutions, which is usually related to plant phenotype change. We demonstrate experimentally that the THz absorption coefficient of leaf could be used for distinguishing plant's physiological stress status, exhibiting clear decreasing or increasing trend under chilling or freezing stress respectively. The underlying rationale might be that membrane damage shows a diverse pattern, changing the intra- or extra-cellular liquid environments, likely being linked to the various THz spectral characteristics. There were different adaptations in leaf morphology, leading to different leaf density, which in turn affects the water volume fraction. Moreover, different patterns of the dynamic equilibrium state of free water and bound water under chilling and freezing treatment were revealed by THz spectroscopy. Here, THz spectroscopic monitoring has shown unique potential for judging citrus's low temperature stress state through bio-water detection and discrimination.
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Affiliation(s)
- Ziyi Zang
- College of Instrumentation and Electrical Engineering, Jilin University, Changchun, Jilin, 130061, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China
| | - Zaoxia Li
- College of Instrumentation and Electrical Engineering, Jilin University, Changchun, Jilin, 130061, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China
| | - Jie Wang
- College of Instrumentation and Electrical Engineering, Jilin University, Changchun, Jilin, 130061, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China
| | - Xingxing Lu
- College of Instrumentation and Electrical Engineering, Jilin University, Changchun, Jilin, 130061, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China
| | - Qiang Lyu
- Citrus Research Institute, Southwest University, Chongqing, 400712, China
| | - Mingjie Tang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China
| | - Hong-Liang Cui
- College of Instrumentation and Electrical Engineering, Jilin University, Changchun, Jilin, 130061, China; Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China.
| | - Shihan Yan
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Science, Chongqing, 400714, China; Chongqing School, University of Chinese Academy of Sciences, Chongqing, 400714, China.
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19
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Tu S, Wang Z, Zhang W, Li Y, She Y, Du H, Yi C, Qin B, Liu Z. A new technology for rapid determination of isomers of hydroxybenzoic acid by terahertz spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc 2022; 279:121313. [PMID: 35598575 DOI: 10.1016/j.saa.2022.121313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/15/2022] [Accepted: 04/23/2022] [Indexed: 06/15/2023]
Abstract
This study investigated the feasibility of using terahertz (THz) technology for the rapid identification of isomers. The time-domain spectra of 2-hydroxybenzoic acid (2-HA), 3-hydroxybenzoic acid (3-HA), and 4-hydroxybenzoic acid (4-HA) were measured by a THz time-domain spectroscopy system (THz-TDS) in the range of 0.3-1.8 THz. Aiming at the isomer classification problem, a THz spectral data classification model based on a variational mode decomposition-particle swarm optimization-support vector machine (VMD-PSO-SVM) method was proposed. Empirical mode decomposition (EMD) and variational mode decomposition (VMD) were used to extract the first eight intrinsic mode functions (IMFs) of the time-domain signal. Principal component analysis (PCA) was used to extract the first 80 principal components of each modal component as the classification feature vector. The particle swarm optimization (PSO) and support vector machine (SVM) algorithms were used to construct 2-, 3-, and 4-HA classification models. We found that the prediction accuracy of the VMD-PSO-SVM model was significantly higher than that of EMD-PSO-SVM model regardless of the modal components. For both EMD and VMD, with the increase in the IMF number, the corresponding classification recognition accuracy tended to decrease. The results showed that the rapid identification model of hydroxybenzoic acid isomers based on THz spectroscopy and SVM was effective and feasible, providing an accurate and rapid method for the chemical synthesis and quality monitoring of biomedicine.
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Affiliation(s)
- Shan Tu
- Key Laboratory of Metallurgical Equipment and Control Technology, Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; Guangxi Key Laboratory of Nuclear Physics and Technology, Guangxi Normal University, Guilin 541004, China; Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; Precision Manufacturing Institute, Wuhan University of Science and Technology, Wuhan 430081, China; Guangxi Key Laboratory of Optoelectronic Information Processing, Guilin University of Electronic Technology, Guilin 541004, China
| | - Zhigang Wang
- Key Laboratory of Metallurgical Equipment and Control Technology, Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; Precision Manufacturing Institute, Wuhan University of Science and Technology, Wuhan 430081, China.
| | - Wentao Zhang
- Guangxi Key Laboratory of Optoelectronic Information Processing, Guilin University of Electronic Technology, Guilin 541004, China.
| | - Yuanpeng Li
- Guangxi Key Laboratory of Nuclear Physics and Technology, Guangxi Normal University, Guilin 541004, China
| | - Yulai She
- Guangxi Key Laboratory of Optoelectronic Information Processing, Guilin University of Electronic Technology, Guilin 541004, China
| | - Hao Du
- Guangxi Key Laboratory of Optoelectronic Information Processing, Guilin University of Electronic Technology, Guilin 541004, China
| | - Cancan Yi
- Key Laboratory of Metallurgical Equipment and Control Technology, Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China; Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; Precision Manufacturing Institute, Wuhan University of Science and Technology, Wuhan 430081, China
| | - Bo Qin
- The 34th Research Institute of CETC, Guilin 541004, China
| | - Zhiqiang Liu
- The 34th Research Institute of CETC, Guilin 541004, China
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20
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Ge M, Wang Y, Zhu J, Wu B, Xu D, Yao J. Low-Frequency Vibrational Spectroscopy Characteristic of Pharmaceutical Carbamazepine Co-Crystals with Nicotinamide and Saccharin. Sensors (Basel) 2022; 22:s22114053. [PMID: 35684674 PMCID: PMC9185236 DOI: 10.3390/s22114053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 05/23/2022] [Accepted: 05/24/2022] [Indexed: 12/10/2022]
Abstract
The pharmaceutical co-crystal has attracted increasing interest due to the improvement of physicochemical properties of active pharmaceutical ingredients. The characterization of pharmaceutical co-crystal is an integral part of the pharmaceutical field. In this paper, the low-frequency vibrational properties for carbamazepine co-crystals with nicotinamide and saccharin (CBZ-NIC and CBZ-SAC) have been characterized by combining the THz spectroscopy with low-wavenumber Raman spectroscopy. The experiment results show that, compared with the individual constituents, CBZ-NIC and CBZ-SAC co-crystals not only have different characteristic absorption peaks in the 0.3-2.5 THz region, but also have significant low-wavenumber Raman characteristic peaks in 0–100 cm−1. Density functional theory was performed to simulate the terahertz and low-wavenumber Raman spectra of the two co-crystals, where the calculation agreed well with the measured vibrational peak positions. The vibrational modes of CBZ-NIC and CBZ-SAC co-crystals were assigned through comparing theoretical results with the experimental spectra. Meanwhile, the low-frequency infrared and/or Raman active of characteristic peaks for such co-crystals were discussed. The results indicate the combination of THz spectroscopy and low-wavenumber Raman spectroscopy can provide more comprehensive low-frequency vibrational information for pharmaceutical co-crystals, such as collective vibration and skeleton vibration, which could play an important role in pharmaceutical science.
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Affiliation(s)
- Meilan Ge
- Institute of Laser and Optoelectronics, School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; (M.G.); (D.X.); (J.Y.)
- Key Laboratory of Optoelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Yuye Wang
- Key Laboratory of Optoelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
- Correspondence:
| | - Junfeng Zhu
- Science and Technology on Electronic Test & Measurement Laboratory, Qingdao 266555, China; (J.Z.); (B.W.)
| | - Bin Wu
- Science and Technology on Electronic Test & Measurement Laboratory, Qingdao 266555, China; (J.Z.); (B.W.)
| | - Degang Xu
- Institute of Laser and Optoelectronics, School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; (M.G.); (D.X.); (J.Y.)
- Key Laboratory of Optoelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Jianquan Yao
- Institute of Laser and Optoelectronics, School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China; (M.G.); (D.X.); (J.Y.)
- Key Laboratory of Optoelectronic Information Technology (Ministry of Education), Tianjin University, Tianjin 300072, China
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21
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Mernea M, Ulăreanu RȘ, Cucu D, Al-Saedi JH, Pop CE, Fendrihan S, Anghelescu GDC, Mihăilescu DF. Epithelial Sodium Channel Inhibition by Amiloride Addressed with THz Spectroscopy and Molecular Modeling. Molecules 2022; 27:3271. [PMID: 35630748 PMCID: PMC9144217 DOI: 10.3390/molecules27103271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/08/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
THz spectroscopy is important for the study of ion channels because it directly addresses the low frequency collective motions relevant for their function. Here we used THz spectroscopy to investigate the inhibition of the epithelial sodium channel (ENaC) by its specific blocker, amiloride. Experiments were performed on A6 cells' suspensions, which are cells overexpressing ENaC derived from Xenopus laevis kidney. THz spectra were investigated with or without amiloride. When ENaC was inhibited by amiloride, a substantial increase in THz absorption was noticed. Molecular modeling methods were used to explain the observed spectroscopic differences. THz spectra were simulated using the structural models of ENaC and ENaC-amiloride complexes built here. The agreement between the experiment and the simulations allowed us to validate the structural models and to describe the amiloride dynamics inside the channel pore. The amiloride binding site validated using THz spectroscopy agrees with previous mutagenesis studies. Altogether, our results show that THz spectroscopy can be successfully used to discriminate between native and inhibited ENaC channels and to characterize the dynamics of channels in the presence of their specific antagonist.
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Affiliation(s)
- Maria Mernea
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Roxana Ștefania Ulăreanu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Dana Cucu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Jasim Hafedh Al-Saedi
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Cristian-Emilian Pop
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania;
- Non-Governmental Research Organization Biologic, 14 Schitului Str., 032044 Bucharest, Romania;
| | - Sergiu Fendrihan
- Non-Governmental Research Organization Biologic, 14 Schitului Str., 032044 Bucharest, Romania;
- Faculty of Medicine, University “Vasile Goldis”, Bulevardul Revoluției 94, 310025 Arad, Romania
| | - Giorgiana Diana Carmen Anghelescu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Dan Florin Mihăilescu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
- Biometric Psychiatric Genetics Research Unit, Alexandru Obregia Psychiatric Hospital, 10 Șoseaua Berceni Str., 041914 Bucharest, Romania
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22
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Ho IH, Chang CW, Chen YL, Chang WY, Kuo TJ, Lu YJ, Gwo S, Ahn H. Ultrathin TiN Epitaxial Films as Transparent Conductive Electrodes. ACS Appl Mater Interfaces 2022; 14:16839-16845. [PMID: 35363462 DOI: 10.1021/acsami.2c00508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Titanium nitride (TiN), a transition-metal compound with tight covalent Ti-N bonding, has a high melting temperature and superior mechanical and chemical stabilities compared to noble metals. With a reduction in thickness, the optical transmittance of TiN films can be drastically increased, and in combination with its excellent electrical conductivity, the ultrathin and continuous TiN film can be considered as an ideal alternative of the metal oxide electrodes. However, the deposition of ultrathin and continuous metallic layer with a smooth surface morphology is a major challenge for typical deposition methods such as thermal evaporation or reactive sputtering. In particular, defects mainly related with oxygen contents and surface scattering can significantly limit the performance of ultrathin TiN films. In this work, ultrathin TiN films with 2-10 nm in thickness are grown by using the nitrogen plasma-assisted molecular-beam epitaxy (MBE) method in an ultrahigh vacuum environment. Excellent surface morphology with a root-mean-square roughness of ≤0.12 nm and a high optical transparency of 75% over the whole visible regime are achieved for ultrathin TiN epitaxial films. The dielectric properties determined by the spectroscopic ellipsometry and the electrical properties measured by the terahertz spectroscopy and the Hall effect method reveal that the percolation thickness of the TiN epitaxial film is less than 2.4 nm and its electrical conductivity is higher than 1.1 × 104 Ω-1 cm-1. These features make MBE-grown ultrathin TiN epitaxial films a good candidate for robust, low cost, and large-area transparent conductive electrodes.
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Affiliation(s)
- I Hong Ho
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Ching-Wen Chang
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Yen-Lin Chen
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Wan-Yu Chang
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Ting-Jui Kuo
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| | - Yu-Jung Lu
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Shangjr Gwo
- Department of Physics, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Hyeyoung Ahn
- Department of Photonics, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
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23
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Wei X, Kong D, Zhu S, Li S, Zhou S, Wu W. Rapid Identification of Soybean Varieties by Terahertz Frequency-Domain Spectroscopy and Grey Wolf Optimizer-Support Vector Machine. Front Plant Sci 2022; 13:823865. [PMID: 35360340 PMCID: PMC8963758 DOI: 10.3389/fpls.2022.823865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Different soybean varieties vary greatly in their nutritional value and composition. Screening for superior varieties is also essential for the development of the soybean seed industry. The objective of the paper was to analyze the feasibility of terahertz (THz) frequency-domain spectroscopy and chemometrics for soybean variety identification. Meanwhile, a grey wolf optimizer-support vector machine (GWO-SVM) soybean variety identification model was proposed. Firstly, the THz frequency-domain spectra of experimental samples (6 varieties, 270 in total) were collected. Principal component analysis (PCA) was used to analyze the THz spectra. After that, 203 samples from the calibration set were used to establish a soybean variety identification model. Finally, 67 samples from the test set were used for prediction validation. The experimental results demonstrated that THz frequency-domain spectroscopy combined with GWO-SVM could quickly and accurately identify soybean varieties. Compared with discriminant partial least squares (DPLS) and particles swarm optimization support vector machine, GWO-SVM combined with the second derivative could establish a better soybean variety identification model. The overall correct identification rate of its prediction set was 97.01%.
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Affiliation(s)
- Xiao Wei
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China
- College of Engineering and Technology, Southwest University, Chongqing, China
| | - Dandan Kong
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China
| | - Shiping Zhu
- College of Engineering and Technology, Southwest University, Chongqing, China
| | - Song Li
- College of Engineering and Technology, Southwest University, Chongqing, China
| | - Shengling Zhou
- College of Engineering and Technology, Southwest University, Chongqing, China
| | - Weiji Wu
- China Tianjin Grain and Oil Wholesale Trade Market, Tianjin, China
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24
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Jin E, Fu S, Hanayama H, Addicoat MA, Wei W, Chen Q, Graf R, Landfester K, Bonn M, Zhang KAI, Wang HI, Müllen K, Narita A. A Nanographene-Based Two-Dimensional Covalent Organic Framework as a Stable and Efficient Photocatalyst. Angew Chem Int Ed Engl 2021; 61:e202114059. [PMID: 34870362 PMCID: PMC9299764 DOI: 10.1002/anie.202114059] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Indexed: 01/14/2023]
Abstract
Synthesis of covalent organic frameworks (COFs) with desirable organic units furnishes advanced materials with unique functionalities. As an emerging class of two‐dimensional (2D) COFs, sp2‐carbon‐conjugated COFs provide a facile platform to build highly stable and crystalline porous polymers. Herein, a 2D olefin‐linked COF was prepared by employing nanographene, namely, dibenzo[hi,st]ovalene (DBOV), as a building block. The DBOV‐COF exhibits unique ABC‐stacked lattices, enhanced stability, and charge‐carrier mobility of ≈0.6 cm2 V−1 s−1 inferred from ultrafast terahertz photoconductivity measurements. The ABC‐stacking structure was revealed by the high‐resolution transmission electron microscopy and powder X‐ray diffraction. DBOV‐COF demonstrated remarkable photocatalytic activity in hydroxylation, which was attributed to the exposure of narrow‐energy‐gap DBOV cores in the COF pores, in conjunction with efficient charge transport following light absorption.
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Affiliation(s)
- Enquan Jin
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Shuai Fu
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Hiroki Hanayama
- Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, 904-0495, Japan
| | - Matthew A Addicoat
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham, NG11 8NS, UK
| | - Wenxin Wei
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Qiang Chen
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Robert Graf
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Katharina Landfester
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Kai A I Zhang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.,Department of Materials Science, Fudan University, Shanghai, 200433, P.R. China
| | - Hai I Wang
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.,Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, 55128, Mainz, Germany
| | - Akimitsu Narita
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany.,Organic and Carbon Nanomaterials Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa, 904-0495, Japan
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25
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Yang J, Jiang S, Xie J, Jiang H, Xu S, Zhang K, Shi Y, Zhang Y, Zeng Z, Fang G, Wang T, Su F. Identifying the Intermediate Free-Carrier Dynamics Across the Charge Separation in Monolayer MoS 2/ReSe 2 Heterostructures. ACS Nano 2021; 15:16760-16768. [PMID: 34549939 DOI: 10.1021/acsnano.1c06822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Van der Waals heterostructures composed of different two-dimensional films offer a unique platform for engineering and promoting photoelectric performances, which highly demands the understanding of photocarrier dynamics. Herein, large-scale vertically stacked heterostructures with MoS2 and ReSe2 monolayers are fabricated. Correspondingly, the carrier dynamics have been thoroughly investigated using different ultrafast spectroscopies, including Terahertz (THz) emission spectroscopy, time-resolved THz spectroscopy (TRTS), and near-infrared optical pump-probe spectroscopy (OPPS), providing complementary dynamic information for the out-of-plane charge separation and in-plane charge transport at different stages. The initial charge transfer (CT) within the first 170 fs, generating a transient directional current, is directly demonstrated by the THz emissions. Furthermore, the TRTS explicitly unveils an intermediate free-carrier relaxation pathway, featuring a pronounced augmentation of THz photoconductivity compared to the isolated ReSe2 layer, which likely contains the evolution from immigrant hot charged free carriers to bounded interlayer excitons (∼0.7 ps) and the surface defect trapping (∼13 ps). In addition, the OPPS reveals a distinct enhancement in the saturable absorption along with long-lived dynamics (∼365 ps), which originated from the CT and interlayer exciton recombination. Our work provides comprehensive insight into the photocarrier dynamics across the charge separation and will help with the development of optoelectronic devices based on ReSe2-MoS2 heterostructures.
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Affiliation(s)
- Jin Yang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Shaolong Jiang
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jiafeng Xie
- GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Huachao Jiang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Shujuan Xu
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
- University of Science and Technology of China, Hefei 230026, China
| | - Kai Zhang
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Yuping Shi
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
| | - Yanfeng Zhang
- Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China
| | - Zhi Zeng
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
| | - Guangyou Fang
- GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Tianwu Wang
- GBA branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Fuhai Su
- Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China
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26
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Izadi S, Han JW, Salloum S, Wolff U, Schnatmann L, Asaithambi A, Matschy S, Schlörb H, Reith H, Perez N, Nielsch K, Schulz S, Mittendorff M, Schierning G. Interface-Dominated Topological Transport in Nanograined Bulk Bi 2 Te 3. Small 2021; 17:e2103281. [PMID: 34545684 DOI: 10.1002/smll.202103281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Revised: 07/23/2021] [Indexed: 06/13/2023]
Abstract
3D topological insulators (TI) host surface carriers with extremely high mobility. However, their transport properties are typically dominated by bulk carriers that outnumber the surface carriers by orders of magnitude. A strategy is herein presented to overcome the problem of bulk carrier domination by using 3D TI nanoparticles, which are compacted by hot pressing to macroscopic nanograined bulk samples. Bi2 Te3 nanoparticles well known for their excellent thermoelectric and 3D TI properties serve as the model system. As key enabler for this approach, a specific synthesis is applied that creates nanoparticles with a low level of impurities and surface contamination. The compacted nanograined bulk contains a high number of interfaces and grain boundaries. Here it is shown that these samples exhibit metallic-like electrical transport properties and a distinct weak antilocalization. A downward trend in the electrical resistivity at temperatures below 5 K is attributed to an increase in the coherence length by applying the Hikami-Larkin-Nagaoka model. THz time-domain spectroscopy reveals a dominance of the surface transport at low frequencies with a mobility of above 103 cm2 V-1 s-1 even at room temperature. These findings clearly demonstrate that nanograined bulk Bi2 Te3 features surface carrier properties that are of importance for technical applications.
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Affiliation(s)
- Sepideh Izadi
- Bielefeld University, Faculty of Physics, Experimental Physics, 33615, Bielefeld, Germany
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Jeong Woo Han
- University of Duisburg-Essen, Faculty of Physics, 47057, Duisburg, Germany
| | - Sarah Salloum
- University of Duisburg-Essen, Faculty of Chemistry, 45141, Essen, Germany
| | - Ulrike Wolff
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Lauritz Schnatmann
- Bielefeld University, Faculty of Physics, Experimental Physics, 33615, Bielefeld, Germany
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
- Institute of Applied Physics, TU Dresden, 01062, Dresden, Germany
| | - Aswin Asaithambi
- University of Duisburg-Essen, Faculty of Physics, 47057, Duisburg, Germany
| | - Sebastian Matschy
- University of Duisburg-Essen, Faculty of Physics, 47057, Duisburg, Germany
| | - Heike Schlörb
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Heiko Reith
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Nicolas Perez
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
| | - Kornelius Nielsch
- Leibniz IFW Dresden, Institute for Metallic Materials, 01069, Dresden, Germany
- Institute of Applied Physics, TU Dresden, 01062, Dresden, Germany
- Institute of Materials Science, TU Dresden, 01062, Dresden, Germany
| | - Stephan Schulz
- University of Duisburg-Essen, Faculty of Chemistry, 45141, Essen, Germany
| | - Martin Mittendorff
- University of Duisburg-Essen, Faculty of Physics, 47057, Duisburg, Germany
| | - Gabi Schierning
- Bielefeld University, Faculty of Physics, Experimental Physics, 33615, Bielefeld, Germany
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27
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Szwagierczak D, Synkiewicz-Musialska B, Kulawik J, Pałka N. Sintering, Microstructure, and Dielectric Properties of Copper Borates for High Frequency LTCC Applications. Materials (Basel) 2021; 14:ma14144017. [PMID: 34300936 PMCID: PMC8303364 DOI: 10.3390/ma14144017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 06/25/2021] [Accepted: 07/13/2021] [Indexed: 12/02/2022]
Abstract
New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.
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Affiliation(s)
- Dorota Szwagierczak
- Łukasiewicz Research Network–Institute of Microelectronics and Photonics, Kraków Division, Zabłocie 39, 30-701 Kraków, Poland; (B.S.-M.); (J.K.)
- Correspondence:
| | - Beata Synkiewicz-Musialska
- Łukasiewicz Research Network–Institute of Microelectronics and Photonics, Kraków Division, Zabłocie 39, 30-701 Kraków, Poland; (B.S.-M.); (J.K.)
| | - Jan Kulawik
- Łukasiewicz Research Network–Institute of Microelectronics and Photonics, Kraków Division, Zabłocie 39, 30-701 Kraków, Poland; (B.S.-M.); (J.K.)
| | - Norbert Pałka
- Institute of Optoelectronics, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warszawa, Poland;
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28
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Yang S, Li C, Mei Y, Liu W, Liu R, Chen W, Han D, Xu K. Determination of the Geographical Origin of Coffee Beans Using Terahertz Spectroscopy Combined With Machine Learning Methods. Front Nutr 2021; 8:680627. [PMID: 34222305 PMCID: PMC8247636 DOI: 10.3389/fnut.2021.680627] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/18/2021] [Indexed: 11/13/2022] Open
Abstract
Different geographical origins can lead to great variance in coffee quality, taste, and commercial value. Hence, controlling the authenticity of the origin of coffee beans is of great importance for producers and consumers worldwide. In this study, terahertz (THz) spectroscopy, combined with machine learning methods, was investigated as a fast and non-destructive method to classify the geographic origin of coffee beans, comparing it with the popular machine learning methods, including convolutional neural network (CNN), linear discriminant analysis (LDA), and support vector machine (SVM) to obtain the best model. The curse of dimensionality will cause some classification methods which are struggling to train effective models. Thus, principal component analysis (PCA) and genetic algorithm (GA) were applied for LDA and SVM to create a smaller set of features. The first nine principal components (PCs) with an accumulative contribution rate of 99.9% extracted by PCA and 21 variables selected by GA were the inputs of LDA and SVM models. The results demonstrate that the excellent classification (accuracy was 90% in a prediction set) could be achieved using a CNN method. The results also indicate variable selecting as an important step to create an accurate and robust discrimination model. The performances of LDA and SVM algorithms could be improved with spectral features extracted by PCA and GA. The GA-SVM has achieved 75% accuracy in a prediction set, while the SVM and PCA-SVM have achieved 50 and 65% accuracy, respectively. These results demonstrate that THz spectroscopy, together with machine learning methods, is an effective and satisfactory approach for classifying geographical origins of coffee beans, suggesting the techniques to tap the potential application of deep learning in the authenticity of agricultural products while expanding the application of THz spectroscopy.
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Affiliation(s)
- Si Yang
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, China.,School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Chenxi Li
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, China.,School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Yang Mei
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, China.,School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Wen Liu
- School of Chemical Engineering, Xiangtan University, Xiangtan, China
| | - Rong Liu
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, China.,School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Wenliang Chen
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, China.,School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
| | - Donghai Han
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Kexin Xu
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin, China.,School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin, China
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29
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Zhang T, Zhang Z, Arnold MA. Crystal Structure-Free Method for Dielectric and Polarizability Characterization of Crystalline Materials at Terahertz Frequencies. Appl Spectrosc 2021; 75:647-653. [PMID: 33683165 DOI: 10.1177/0003702821991594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Terahertz (THz) time-domain spectroscopy provides a direct and nondestructive method for measuring the dielectric properties of materials directly from the phase delay of coherent electromagnetic radiation propagating through the sample. In cases when crystals are embedded within an inert polymeric pellet, the Landau, Lifshitz, and Looyenga (LLL) effective medium model can be used to extract the intrinsic dielectric constant of the crystalline sample. Subsequently, polarizability can be obtained from the Clausius-Mossotti (CM) relationship. Knowledge of the crystal structure density is required for an analytical solution to the LLL and CM relationships. A novel crystal structure-free graphical method is presented as a way to estimate both dielectric constants and polarizability values for the situation when the crystal structure density is unknown, and the crystals are embedded within a pellet composed of a non-porous polymer. The utility of this crystal structure-free method is demonstrated by analyzing THz time-domain spectra collected for a set of amino acids (L-alanine, L-threonine, and L-glutamine) embedded within pellets composed of polytetrafluoroethylene. Crystal structures are known for each amino acid, thereby enabling a direct comparison of results using the analytical solution and the proposed crystal structure-free graphical method. For each amino acid, the intrinsic dielectric constant is extracted through the LLL effective medium model without using information of their crystal structure densities. THz polarizabilities are then calculated with the CM relationship by using the determined intrinsic dielectric constant for each amino acid coupled with its crystal density as determined graphically. Comparison between the analytical and graphical solutions reveal relative differences between dielectric constants of 3.7, 5.1, and 13.6% for threonine, alanine, and glutamine, respectively, and relative differences between polarizability of 0.6, 0.9, and 5.4%, respectively. These values were determined over the 10-20 cm-1 THz frequency range. The proposed method requires no prior knowledge of crystal structure information.
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Affiliation(s)
- Tianyao Zhang
- Beijing Engineering Research Center of Industrial Spectrum Imaging, 12507University of Science and Technology Beijing, Beijing, China
- Department of Chemistry and Optical Science and Technology Center, 4083University of Iowa, Iowa City, IA, USA
- Department of Materials Physics, 12507University of Science and Technology Beijing, Beijing, China
| | - Zhaohui Zhang
- Beijing Engineering Research Center of Industrial Spectrum Imaging, 12507University of Science and Technology Beijing, Beijing, China
| | - Mark A Arnold
- Department of Chemistry and Optical Science and Technology Center, 4083University of Iowa, Iowa City, IA, USA
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30
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Sebastiani F, Ma CY, Funke S, Bäumer A, Decka D, Hoberg C, Esser A, Forbert H, Schwaab G, Marx D, Havenith M. Probing Local Electrostatics of Glycine in Aqueous Solution by THz Spectroscopy. Angew Chem Int Ed Engl 2021; 60:3768-3772. [PMID: 33156972 PMCID: PMC7898531 DOI: 10.1002/anie.202014133] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Indexed: 11/13/2022]
Abstract
Based upon precise terahertz (THz) measurements of the solvated amino acid glycine and accompanying ab-initio molecular-dynamics simulations, we show that the N-C-C-O open/close mode at 315 cm-1 serves as a sensitive, label-free probe for the local protonation of the amide group. Experimentally, we can show that this holds not only for glycine but also for diglycine and valine. The approach is more general, since the changes due to protonation result in intensity changes which can be probed by THz time domain (0-50 cm-1 ) as well as by precise THz-FT spectroscopy (50-400 cm-1 ). A detailed analysis allows us to directly correlate the titration spectra with pKa values. This demonstrates the potential of THz spectroscopy to probe the charge state of a natural amino acid in water in a label-free manner.
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Affiliation(s)
- Federico Sebastiani
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Chun Yu Ma
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Sarah Funke
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Alexander Bäumer
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Dominique Decka
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Claudius Hoberg
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Alexander Esser
- Lehrstuhl für Theoretische ChemieRuhr-Universität Bochum44780BochumGermany
| | - Harald Forbert
- Center for Solvation Science ZEMOSRuhr-Universität Bochum44780BochumGermany
| | - Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
| | - Dominik Marx
- Lehrstuhl für Theoretische ChemieRuhr-Universität Bochum44780BochumGermany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie IIRuhr-Universität Bochum44780BochumGermany
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31
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Gorokhov G, Bychanok D, Gayduchenko I, Rogov Y, Zhukova E, Zhukov S, Kadyrov L, Fedorov G, Ivanov E, Kotsilkova R, Macutkevic J, Kuzhir P. THz Spectroscopy as a Versatile Tool for Filler Distribution Diagnostics in Polymer Nanocomposites. Polymers (Basel) 2020; 12:E3037. [PMID: 33353036 PMCID: PMC7767186 DOI: 10.3390/polym12123037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 12/20/2022] Open
Abstract
Polymer composites containing nanocarbon fillers are under intensive investigation worldwide due to their remarkable electromagnetic properties distinguished not only by components as such, but the distribution and interaction of the fillers inside the polymer matrix. The theory herein reveals that a particular effect connected with the homogeneity of a composite manifests itself in the terahertz range. Transmission time-domain terahertz spectroscopy was applied to the investigation of nanocomposites obtained by co-extrusion of PLA polymer with additions of graphene nanoplatelets and multi-walled carbon nanotubes. The THz peak of permittivity's imaginary part predicted by the applied model was experimentally shown for GNP-containing composites both below and above the percolation threshold. The physical nature of the peak was explained by the impact on filler particles excluded from the percolation network due to the peculiarities of filler distribution. Terahertz spectroscopy as a versatile instrument of filler distribution diagnostics is discussed.
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Affiliation(s)
- Gleb Gorokhov
- Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str., 11, 220006 Minsk, Belarus; (D.B.); (P.K.)
- Physics Faculty, Vilnius University, Sauletekio 9, LT-10222 Vilnius, Lithuania;
| | - Dzmitry Bychanok
- Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str., 11, 220006 Minsk, Belarus; (D.B.); (P.K.)
- Radiophysics Department, Tomsk State University, Lenin Avenue 36, 634050 Tomsk, Russia
| | - Igor Gayduchenko
- Moscow Pedagogical State University, Malaya Pirogovskaya Str., 1/1, 119991 Moscow, Russia;
| | - Yuriy Rogov
- Moscow Institute of Physics and Technology, Institutskiy per., 9, 141701 Dolgoprudny, Russia; (Y.R.); (E.Z.); (S.Z.); (L.K.); (G.F.)
| | - Elena Zhukova
- Moscow Institute of Physics and Technology, Institutskiy per., 9, 141701 Dolgoprudny, Russia; (Y.R.); (E.Z.); (S.Z.); (L.K.); (G.F.)
| | - Sergei Zhukov
- Moscow Institute of Physics and Technology, Institutskiy per., 9, 141701 Dolgoprudny, Russia; (Y.R.); (E.Z.); (S.Z.); (L.K.); (G.F.)
| | - Lenar Kadyrov
- Moscow Institute of Physics and Technology, Institutskiy per., 9, 141701 Dolgoprudny, Russia; (Y.R.); (E.Z.); (S.Z.); (L.K.); (G.F.)
| | - Georgy Fedorov
- Moscow Institute of Physics and Technology, Institutskiy per., 9, 141701 Dolgoprudny, Russia; (Y.R.); (E.Z.); (S.Z.); (L.K.); (G.F.)
| | - Evgeni Ivanov
- OLEM, Institute of Mechanics Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 4, 1113 Sofia, Bulgaria; (E.I.); (R.K.)
- Research and Development of Nanomaterials and Nanotechnologies (NanoTech Lab Ltd.), Acad. G. Bonchev Str. Block 4, 1113 Sofia, Bulgaria
| | - Rumiana Kotsilkova
- OLEM, Institute of Mechanics Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 4, 1113 Sofia, Bulgaria; (E.I.); (R.K.)
| | - Jan Macutkevic
- Physics Faculty, Vilnius University, Sauletekio 9, LT-10222 Vilnius, Lithuania;
| | - Polina Kuzhir
- Institute for Nuclear Problems of Belarusian State University, Bobruiskaya Str., 11, 220006 Minsk, Belarus; (D.B.); (P.K.)
- Institute of Photonics, University of Eastern Finland, Yliopistokatu 7, FI-80101 Joensuu, Finland
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32
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Sebastiani F, Bender TA, Pezzotti S, Li WL, Schwaab G, Bergman RG, Raymond KN, Toste FD, Head-Gordon T, Havenith M. An isolated water droplet in the aqueous solution of a supramolecular tetrahedral cage. Proc Natl Acad Sci U S A 2020; 117:32954-61. [PMID: 33318176 DOI: 10.1073/pnas.2012545117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Water under nanoconfinement at ambient conditions has exhibited low-dimensional ice formation and liquid-solid phase transitions, but with structural and dynamical signatures that map onto known regions of water's phase diagram. Using terahertz (THz) absorption spectroscopy and ab initio molecular dynamics, we have investigated the ambient water confined in a supramolecular tetrahedral assembly, and determined that a dynamically distinct network of 9 ± 1 water molecules is present within the nanocavity of the host. The low-frequency absorption spectrum and theoretical analysis of the water in the Ga4L6 12- host demonstrate that the structure and dynamics of the encapsulated droplet is distinct from any known phase of water. A further inference is that the release of the highly unusual encapsulated water droplet creates a strong thermodynamic driver for the high-affinity binding of guests in aqueous solution for the Ga4L6 12- supramolecular construct.
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33
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Betancur-Pérez A, Martín-Mateos P, Dios C, Acedo P. Design of a Multipurpose Photonic Chip Architecture for THz Dual-Comb Spectrometers. Sensors (Basel) 2020; 20:E6089. [PMID: 33120866 DOI: 10.3390/s20216089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/18/2020] [Accepted: 09/22/2020] [Indexed: 12/18/2022]
Abstract
In this work, we present a multipurpose photonic integrated circuit capable of generating multiheterodyne complex Dual-Combs (DC) THz signals. Our work focuses on translating the functionality of an electro-optic tunable DC system into a photonic chip employing standard building blocks to ensure the scalability and cost efficiency of the integrated device. The architecture we analyze for integration is based on three stages: a seed comb, a mode selection stage and a DC stage. This final DC stage includes a frequency shifter, a key element to improve the final detection of the THz signals and obtain real-time operation. This investigation covers three key aspects: (1) a solution for comb line selection on GHz spaced combs using OIL or OPLL on photonic chips is studied and evaluated, (2) a simple and versatile scheme to produce a frequency shift using the double sideband suppressed carrier modulation technique and an asymmetric Mach Zehnder Interferometer to filter one of the sidebands is proposed, and (3) a multipurpose architecture that can offer a versatile effective device, moving from application-specific PICs to general-purpose PICs. Using the building blocks (BBs) available from an InP-based foundry, we obtained simulations that offer a high-quality Dual-Comb frequency shifted signal with a side mode suppression ratio around 21 dB, and 41 dB after photodetection with an intermediate frequency of 1 MHz. We tested our system to generate a Dual-Comb with 10 kHz of frequency spacing and an OOK modulation with 5 Gbps which can be down-converted to the THz range by a square law detector. It is also important to note that the presented architecture is multipurpose and can also be applied to THz communications. This design is a step to enable a commercial THz photonic chip for multiple applications such as THz spectroscopy, THz multispectral imaging and THz telecommunications and offers the possibility of being fabricated in a multi-project wafer.
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34
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Abreu E, Meyers D, Thorsmølle VK, Zhang J, Liu X, Geng K, Chakhalian J, Averitt RD. Nucleation and Growth Bottleneck in the Conductivity Recovery Dynamics of Nickelate Ultrathin Films. Nano Lett 2020; 20:7422-7428. [PMID: 32902285 DOI: 10.1021/acs.nanolett.0c02828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate THz conductivity dynamics in NdNiO3 and EuNiO3 ultrathin films (15 unit cells, u.c., ∼5.7 nm thick) following a photoinduced thermal quench into the metallic state and reveal a clear contrast between first- and second-order dynamics. While in EuNiO3 the conductivity recovers exponentially, in NdNiO3 the recovery is nonexponential and slower than a simple thermal model. Crucially, it is consistent with first-order dynamics and well-described by a 2d Avrami model, with supercooling leading to metastable phase coexistence on the nano- to mesoscopic scale. This novel observation is a fundamentally dynamic manifestation of the first-order character of the insulator-to-metal transition, which the nanoscale thickness of our films and their fast cooling rate enable us to detect. The large transients seen in our films are promising for fast electronic (and magnetic) switching applications.
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Affiliation(s)
- E Abreu
- Institute for Quantum Electronics, Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D Meyers
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - V K Thorsmølle
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
| | - J Zhang
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - X Liu
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - K Geng
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
| | - J Chakhalian
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - R D Averitt
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
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35
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Abstract
With the dramatic development of source and detector components, terahertz (THz) spectroscopy technology has recently shown a renaissance in various fields such as medical, material, biosensing and pharmaceutical industry. As a rapid and noninvasive technology, it has been extensively exploited to evaluate food quality and ensure food safety. In this review, the principles and processes of THz spectroscopy are first discussed. The current state-of-the-art applications of THz and imaging technologies focused on foodstuffs are then discussed. The advantages and challenges are also covered. This review offers detailed information for recent efforts dedicated to THz for monitoring the quality and safety of various food commodities and the feasibility of its widespread application. THz technology, as an emerging and unique method, is potentially applied for detecting food processing and maintaining quality and safety.
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Affiliation(s)
- Chao-Hui Feng
- RIKEN Centre for Advanced Photonics, RIKEN, Sendai, Japan
| | - Chiko Otani
- RIKEN Centre for Advanced Photonics, RIKEN, Sendai, Japan.,Department of Physics, Tohoku University, Sendai, Miyagi, Japan
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36
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Tries A, Osella S, Zhang P, Xu F, Ramanan C, Kläui M, Mai Y, Beljonne D, Wang HI. Experimental Observation of Strong Exciton Effects in Graphene Nanoribbons. Nano Lett 2020; 20:2993-3002. [PMID: 32207957 PMCID: PMC7311082 DOI: 10.1021/acs.nanolett.9b04816] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/21/2020] [Indexed: 05/29/2023]
Abstract
Graphene nanoribbons (GNRs) with atomically precise width and edge structures are a promising class of nanomaterials for optoelectronics, thanks to their semiconducting nature and high mobility of charge carriers. Understanding the fundamental static optical properties and ultrafast dynamics of charge carrier generation in GNRs is essential for optoelectronic applications. Combining THz spectroscopy and theoretical calculations, we report a strong exciton effect with binding energy up to ∼700 meV in liquid-phase-dispersed GNRs with a width of 1.7 nm and an optical band gap of ∼1.6 eV, illustrating the intrinsically strong Coulomb interactions between photogenerated electrons and holes. By tracking the exciton dynamics, we reveal an ultrafast formation of excitons in GNRs with a long lifetime over 100 ps. Our results not only reveal fundamental aspects of excitons in GNRs (strong binding energy and ultrafast exciton formation etc.) but also highlight promising properties of GNRs for optoelectronic devices.
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Affiliation(s)
- Alexander Tries
- Max
Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
- Institute
of Physics and Graduate School of Excellence Material Sciences in
Mainz, Johannes Gutenberg-University Mainz, D-55128 Mainz, Germany
| | - Silvio Osella
- Chemical
and Biological Systems Simulation Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
| | - Pengfei Zhang
- School
of Chemistry and Chemical Engineering, Frontiers Science Center for
Transformative Molecules, Shanghai Jiao
Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Fugui Xu
- School
of Chemistry and Chemical Engineering, Frontiers Science Center for
Transformative Molecules, Shanghai Jiao
Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Charusheela Ramanan
- Max
Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Mathias Kläui
- Institute
of Physics and Graduate School of Excellence Material Sciences in
Mainz, Johannes Gutenberg-University Mainz, D-55128 Mainz, Germany
| | - Yiyong Mai
- School
of Chemistry and Chemical Engineering, Frontiers Science Center for
Transformative Molecules, Shanghai Jiao
Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - David Beljonne
- Laboratory
for Chemistry of Novel Materials, Université
de Mons, Place du Parc,
20, B-7000 Mons, Belgium
| | - Hai I. Wang
- Max
Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
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37
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Yavorskiy D, Szoła M, Karpierz K, Rudniewski R, Bożek R, Karczewski G, Wojtowicz T, Wróbel J, Łusakowski J. Polarization of Magnetoplasmons in Grating Metamaterials Based on CdTe/CdMgTe Quantum Wells. Materials (Basel) 2020; 13:ma13081811. [PMID: 32290498 PMCID: PMC7215284 DOI: 10.3390/ma13081811] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 11/25/2022]
Abstract
Grating metamaterials were fabricated with electron beam lithography on CdTe/CdMgTe modulation doped structures with two non-interacting quantum wells. Two types of samples were studied: with etched gratings and with gratings formed by deposition of Au stripes. The polarization properties at THz frequencies of the gratings were determined at room temperature. It was shown that Au gratings formed a linear polarizer, while etched gratings did not polarize THz radiation. Transmission of circularly polarized THz radiation at low temperatures through a sample with no grating showed a strongly circularly polarized cyclotron resonance transition. Transmission of this radiation through a sample with an etched grating showed a magnetoplasmon transition that was almost perfectly linearly polarized. We concluded that magnetoplasmons in metamaterials with etched gratings are linearly polarized excitations, possibly with a small contribution of a circular component. This work opens the possibility of the detailed study of the polarization of magnetoplasmons, which has not been explored in the past.
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Affiliation(s)
- Dmitriy Yavorskiy
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Centera Laboratories, Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Maria Szoła
- Centera Laboratories, Institute of High Pressure Physics, Polish Academy of Sciences, ul. Sokołowska 29/37, 01-142 Warsaw, Poland
| | - Krzysztof Karpierz
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Rafał Rudniewski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Rafał Bożek
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Grzegorz Karczewski
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Tomasz Wojtowicz
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Jerzy Wróbel
- Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
| | - Jerzy Łusakowski
- Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Correspondence:
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38
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Ballabio M, Fuertes Marrón D, Barreau N, Bonn M, Cánovas E. Composition-Dependent Passivation Efficiency at the CdS/CuIn 1- x Ga x Se 2 Interface. Adv Mater 2020; 32:e1907763. [PMID: 31984586 DOI: 10.1002/adma.201907763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/24/2019] [Indexed: 06/10/2023]
Abstract
The bandgap of CuIn1- x Gax Se2 (CIGS) chalcopyrite semiconductors can be tuned between ≈1.0 and ≈1.7 eV for Ga contents ranging between x = 0 and x = 1. While an optimum bandgap of 1.34 eV is desirable for achieving maximum solar energy conversion in solar cells, state-of-the-art CIGS-based devices experience a drop in efficiency for Ga contents x > 0.3 (i.e., for bandgaps >1.2 eV), an aspect that is limiting the full potential of these devices. The mechanism underlying the limited performance as a function of CIGS composition has remained elusive: both surface and bulk recombination effects are proposed. Here, the disentanglement between surface and bulk effects in CIGS absorbers as a function of Ga content is achieved by comparing photogenerated charge carrier dynamics in air/CIGS and surface-passivated ZnO/CdS/CIGS samples. While surface passivation prevents surface recombination of charge carriers for low Ga content (x < 0.3; up to 1.2 eV bandgap), surface recombination dominates for higher-bandgap materials. The results thus demonstrate that surface, rather than bulk effects, is responsible for the drop in efficiency for Ga contents larger than x ≈ 0.3.
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Affiliation(s)
- Marco Ballabio
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - David Fuertes Marrón
- Instituto de Energía Solar, Universidad Politécnica de Madrid, ETSI Telecomunicación, Avda. Complutense 30, 28040, Madrid, Spain
| | - Nicolas Barreau
- Institut des Matériaux Jean Rouxel (IMN) - UMR6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322, Nantes Cedex 3, France
| | - Mischa Bonn
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Enrique Cánovas
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia), Faraday 9, 28049, Madrid, Spain
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39
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K M H, S Madan K, B C M, R N. Vibrational analysis and physical property studies of 6-Methoxy-2-[(E)-phenyliminomethyl]-phenol in the THz, IR and UV-visible spectral regions. Spectrochim Acta A Mol Biomol Spectrosc 2019; 222:117227. [PMID: 31181507 DOI: 10.1016/j.saa.2019.117227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 06/09/2023]
Abstract
Bulk single crystals of 6-Methoxy-2-[(E)-phenyliminomethyl]phenol were grown after preparing the material by Schiff base condensation of ortho-vanillin alternatively called 2-hydroxy-3-methoxybenzaldehyde and aniline. The three dimensional molecular and crystal structure of the title compound is confirmed by X-ray diffraction. Molecules crystallized in the orthorhombic crystal system and noncentrosymmetric space group P212121. Geometry optimization, vibrational analysis, Calculation of HOMO-LUMO band gap and molecular hyperpolarizability of the proposed material have been carried out. Terahertz time domain spectroscopic studies have been performed and the refractive index and absorption coefficient of material is calculated in the THz regime. Molecular vibrations responsible for different THz phonon modes are identified with the help of density functional theory based calculations.
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Affiliation(s)
- Hijas K M
- Intermetallic and nonlinear optics laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli 620015, India
| | - Kumar S Madan
- DST-PURSE lab, Mangalore university, Mangalagangotri, 574199, India
| | - Manjunath B C
- Department of physics, Yuvaraja's college, University of Mysore, 570005, India
| | - Nagalakshmi R
- Intermetallic and nonlinear optics laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli 620015, India.
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40
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Svirinovsky-Arbeli A, Rosenberg D, Krotkov D, Damari R, Kundu K, Feintuch A, Houben L, Fleischer S, Leskes M. The effects of sample conductivity on the efficacy of dynamic nuclear polarization for sensitivity enhancement in solid state NMR spectroscopy. Solid State Nucl Magn Reson 2019; 99:7-14. [PMID: 30826711 DOI: 10.1016/j.ssnmr.2019.02.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/17/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
In recent years dynamic nuclear polarization (DNP) has greatly expanded the range of materials systems that can be studied by solid state NMR spectroscopy. To date, the majority of systems studied by DNP were insulating materials including organic and inorganic solids. However, many technologically-relevant materials used in energy conversion and storage systems are electrically conductive to some extent or are employed as composites containing conductive additives. Such materials introduce challenges in their study by DNP-NMR which include microwave absorption and sample heating that were not thoroughly investigated so far. Here we examine several commercial carbon allotropes, commonly employed as electrodes or conductive additives, and consider their effect on the extent of solvent polarization achieved in DNP from nitroxide biradicals. We then address the effect of sample conductivity systematically by studying a series of carbons with increasing electrical conductivity prepared via glucose carbonization. THz spectroscopy measurements are used to determine the extent of μw absorption. Our results show that while the DNP performance significantly drops in samples containing the highly conductive carbons, sufficient signal enhancement can still be achieved with some compromise on conductivity. Furthermore, we show that the deleterious effect of conductive additives on DNP enhancements can be partially overcome through pulse-DNP experiments.
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Affiliation(s)
- Asya Svirinovsky-Arbeli
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Dina Rosenberg
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry and the Tel-Aviv Center for Light-Matter-Interaction, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Daniel Krotkov
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry and the Tel-Aviv Center for Light-Matter-Interaction, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Ran Damari
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry and the Tel-Aviv Center for Light-Matter-Interaction, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Krishnendu Kundu
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Akiva Feintuch
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Lothar Houben
- Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Sharly Fleischer
- Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry and the Tel-Aviv Center for Light-Matter-Interaction, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Michal Leskes
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot, 7610001, Israel.
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41
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Zhang R, Liu S, Jin H, Luo Y, Zheng Z, Gao F, Zheng Y. Noninvasive Electromagnetic Wave Sensing of Glucose. Sensors (Basel) 2019; 19:E1151. [PMID: 30866459 PMCID: PMC6427587 DOI: 10.3390/s19051151] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 02/01/2019] [Accepted: 02/10/2019] [Indexed: 01/10/2023]
Abstract
Diabetic patients need long-term and frequent glucose monitoring to assist in insulin intake. The current finger-prick devices are painful and costly, which places noninvasive glucose sensors in high demand. In this review paper, we list several advanced electromagnetic (EM)-wave-based technologies for noninvasive glucose measurement, including infrared (IR) spectroscopy, photoacoustic (PA) spectroscopy, Raman spectroscopy, fluorescence, optical coherence tomography (OCT), Terahertz (THz) spectroscopy, and microwave sensing. The development of each method is discussed regarding the fundamental principle, system setup, and experimental results. Despite the promising achievements that have been previously reported, no established product has obtained FDA approval or survived a marketing test. The limitations of, and prospects for, these techniques are presented at the end of this review.
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Affiliation(s)
- Ruochong Zhang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Siyu Liu
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Haoran Jin
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Yunqi Luo
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Zesheng Zheng
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
| | - Fei Gao
- School of Information Science and Technology, ShanghaiTech University, Shanghai 201210, China.
| | - Yuanjin Zheng
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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42
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Zhang T, Zhang Z, Arnold MA. Polarizability of Aspirin at Terahertz Frequencies Using Terahertz Time Domain Spectroscopy (THz-TDS). Appl Spectrosc 2019; 73:253-260. [PMID: 30394798 DOI: 10.1177/0003702818815177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A novel application of terahertz time-domain spectroscopy (THz-TDS) is described for the determination of permittivity and polarizability of organic crystals, as exemplified by measurements with the polymorph I form of crystalline aspirin (acetylsalicylic acid). The coherent nature of the THz pulse experiment, coupled with gated-detection, permits direct measure of differences in the phase angle of the electric field vector after passing through a pellet composed of the aspirin crystals embedded within an inert polymer matrix. An effective media model is used to extract dielectric information for the crystals from the measured time-domain signal that is representative of the entire pellet composition. Polarizability is then obtained for these organic crystals by using the Clausius-Mossotti relationship. Dielectric spectra and polarizability spectra are presented over the 0.3-3 THz frequency range (10-100 cm-1). The average polarizability values measured over the low frequency range (10-20 cm-1) are 22.4 ± 0.3 and 22.4 ± 0.5 Å3 for aspirin crystals embedded within matrixes of polytetrafluoroethylene (PTFE) and polyethylene (PE), respectively.
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Affiliation(s)
- Tianyao Zhang
- 1 Department of Instrumentation Science, University of Science and Technology Beijing, Beijing, China
- 2 Department of Chemistry and Optical Science and Technology Center, University of Iowa, Iowa City, IA, USA
| | - Zhaohui Zhang
- 1 Department of Instrumentation Science, University of Science and Technology Beijing, Beijing, China
| | - Mark A Arnold
- 2 Department of Chemistry and Optical Science and Technology Center, University of Iowa, Iowa City, IA, USA
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43
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Berger A, Ciardi G, Sidler D, Hamm P, Shalit A. Impact of nuclear quantum effects on the structural inhomogeneity of liquid water. Proc Natl Acad Sci U S A 2019; 116:2458-63. [PMID: 30692247 DOI: 10.1073/pnas.1818182116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The 2D Raman-terahertz (THz) response of liquid water is studied in dependence of temperature and isotope substitution ([Formula: see text]O, [Formula: see text]O, and [Formula: see text]O). In either case, a very short-lived (i.e., between 75 and 95 fs) echo is observed that reports on the inhomogeneity of the low-frequency intermolecular modes and hence, on the heterogeneity of the hydrogen bond networks of water. The echo lifetime slows down by about 20% when cooling the liquid from room temperature to the freezing point. Furthermore, the echo lifetime of [Formula: see text]O is [Formula: see text] slower than that of [Formula: see text]O, and both can be mapped on each other by introducing an effective temperature shift of [Formula: see text] K. In contrast, the temperature-dependent echo lifetimes of [Formula: see text]O and [Formula: see text]O are the same within error. [Formula: see text]O and [Formula: see text]O have identical masses, yet [Formula: see text]O is much closer to [Formula: see text]O in terms of nuclear quantum effects. It is, therefore, concluded that the echo is a measure of the structural inhomogeneity of liquid water induced by nuclear quantum effects.
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Shin HJ, Jang HW, Ok G. Highly Sensitive Detection of 4-Methylimidazole Using a Terahertz Metamaterial. Sensors (Basel) 2018; 18:E4304. [PMID: 30563253 DOI: 10.3390/s18124304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/03/2018] [Accepted: 12/04/2018] [Indexed: 01/01/2023]
Abstract
In this study, we demonstrated a highly sensitive detection method of 4-methylimidazole (4-MeI), a carcinogenic material, by using a terahertz (THz) metamaterial at a THz region. The THz metamaterials were fabricated with a metal array, using an electric-field-coupled inductor-capacitor (ELC) resonator structure, and a finite-difference time-domain (FDTD) simulation showed good agreement with the experimental results. We measured the THz spectra of the metamaterials to detect the 4-MeI concentrations of 0, 1, 2, 5, 10, 15, and 20 mg/L. The resonance frequency of the metamaterial was shifted by, approximately, 8 GHz and transmittance at the resonance frequency increased to 2 × 10−3, as the concentration was increased, up to 20 mg/L. Our study provides new insight into the application of metamaterials in detecting carcinogens, using a THz technique.
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Ge H, Jiang Y, Zhang Y. THz Spectroscopic Investigation of Wheat-Quality by Using Multi-Source Data Fusion. Sensors (Basel) 2018; 18:s18113945. [PMID: 30441868 PMCID: PMC6263950 DOI: 10.3390/s18113945] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/04/2018] [Accepted: 11/09/2018] [Indexed: 11/30/2022]
Abstract
In order to improve the detection accuracy for the quality of wheat, a recognition method for wheat quality using the terahertz (THz) spectrum and multi-source information fusion technology is proposed. Through a combination of the absorption and the refractive index spectra of samples of normal, germinated, moldy, and worm-eaten wheat, support vector machine (SVM) and Dempster-Shafer (DS) evidence theory with different kernel functions were used to establish a classification fusion model for the multiple optical indexes of wheat. The results showed that the recognition rate of the fusion model for wheat samples can be as high as 96%. Furthermore, this approach was compared to the regression model based on single-spectrum analysis. The results indicate that the average recognition rates of fusion models for wheat can reach 90%, and the recognition rate of the SVM radial basis function (SVM-RBF) fusion model can reach 97.5%. The preliminary results indicated that THz-TDS combined with DS evidence theory analysis was suitable for the determination of the wheat quality with better detection accuracy.
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Affiliation(s)
- Hongyi Ge
- Key Laboratory of Grain Information Processing & Control, Ministry of Education, Henan University of Technology, Zhengzhou 450001, China.
- College of Information Science and Engineering, Henan University of Technology, Zhengzhou 450001, China.
- Key Laboratory of Henan Province for Grain Photoelectric Detection and Control, Zhengzhou 450001, China.
| | - Yuying Jiang
- Key Laboratory of Grain Information Processing & Control, Ministry of Education, Henan University of Technology, Zhengzhou 450001, China.
- Key Laboratory of Henan Province for Grain Photoelectric Detection and Control, Zhengzhou 450001, China.
| | - Yuan Zhang
- Key Laboratory of Grain Information Processing & Control, Ministry of Education, Henan University of Technology, Zhengzhou 450001, China.
- Key Laboratory of Henan Province for Grain Photoelectric Detection and Control, Zhengzhou 450001, China.
- National Engineering Laboratory for Wheat & Corn Further Processing, Zhengzhou 450001, China.
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46
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Schwaab G, Sebastiani F, Havenith M. Ion Hydration and Ion Pairing as Probed by THz Spectroscopy. Angew Chem Int Ed Engl 2018; 58:3000-3013. [PMID: 30022575 DOI: 10.1002/anie.201805261] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/17/2018] [Indexed: 11/12/2022]
Abstract
Ion hydration is of pivotal importance for many fundamental processes. Various spectroscopic methods are used to study the retardation of the hydration bond dynamics in the vicinity of anions and cations. Here we introduce THz-FTIR spectroscopy as a powerful method to answer the open questions. We show through dissection of THz spectra that we can pinpoint characteristic absorption features that can be attributed to the rattling modes of strongly hydrating ions within their hydration cages as well as vibrationally induced charge fluctuations in the case of weakly hydrating ions. Further analysis yields information on anion-cation cooperativity, the size of the dynamic hydration shell, as well as the lifetimes of these collective ion-hydration water modes and their connecting thermal bath states. Our study provides evidence for a non-additive behavior, thus questioning the simplified Hofmeister model. THz spectroscopy enables ion pairing to be observed and quantified at a high salt concentration.
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Affiliation(s)
- Gerhard Schwaab
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Federico Sebastiani
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
| | - Martina Havenith
- Lehrstuhl für Physikalische Chemie II, Ruhr-Universität Bochum, 44780, Bochum, Germany
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Milot RL, Klug MT, Davies CL, Wang Z, Kraus H, Snaith HJ, Johnston MB, Herz LM. The Effects of Doping Density and Temperature on the Optoelectronic Properties of Formamidinium Tin Triiodide Thin Films. Adv Mater 2018; 30:e1804506. [PMID: 30222220 DOI: 10.1002/adma.201804506] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Revised: 08/14/2018] [Indexed: 05/02/2023]
Abstract
Optoelectronic properties are unraveled for formamidinium tin triiodide (FASnI3 ) thin films, whose background hole doping density is varied through SnF2 addition during film fabrication. Monomolecular charge-carrier recombination exhibits both a dopant-mediated part that grows linearly with hole doping density and remnant contributions that remain under tin-enriched processing conditions. At hole densities near 1020 cm-3 , a strong Burstein-Moss effect increases absorption onset energies by ≈300 meV beyond the bandgap energy of undoped FASnI3 (shown to be 1.2 eV at 5 K and 1.35 eV at room temperature). At very high doping densities (1020 cm-3 ), temperature-dependent measurements indicate that the effective charge-carrier mobility is suppressed through scattering with ionized dopants. Once the background hole concentration is nearer 1019 cm-3 and below, the charge-carrier mobility increases with decreasing temperature according to ≈T-1.2 , suggesting that it is limited mostly by intrinsic interactions with lattice vibrations. For the lowest doping concentration of 7.2 × 1018 cm-3 , charge-carrier mobilities reach a value of 67 cm2 V-1 s-1 at room temperature and 470 cm2 V-1 s-1 at 50 K. Intraexcitonic transitions observed in the THz-frequency photoconductivity spectra at 5 K reveal an exciton binding energy of only 3.1 meV for FASnI3 , in agreement with the low bandgap energy exhibited by this perovskite.
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Affiliation(s)
- Rebecca L Milot
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
- Department of Physics, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, UK
| | - Matthew T Klug
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Christopher L Davies
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Zhiping Wang
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Hans Kraus
- Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH, UK
| | - Henry J Snaith
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Michael B Johnston
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
| | - Laura M Herz
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
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48
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Hand K, Yates E. Terahertz: dictating the frequency of life. Do macromolecular vibrational modes impose thermal limitations on terrestrial life? J R Soc Interface 2018; 14:rsif.2017.0673. [PMID: 29142018 DOI: 10.1098/rsif.2017.0673] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/25/2017] [Indexed: 11/12/2022] Open
Abstract
Conditions on exoplanets include elevated temperatures and pressures. The response of carbon-based biological macromolecules to such conditions is then relevant to the viability of life. The capacity of proteins and ribozymes to catalyse reactions or bind receptors, and nucleic acids to convey information, depends on them sampling different conformational states. These are determined by macromolecular vibrational states, or phonon modes, accessible using terahertz (THz: 1012Hz) absorption spectroscopy. THz spectra of biological macromolecules exhibit broad absorption at approximately 6 THz (equating to approx. 280 K) corresponding to dense transitions between phonon modes. There are also troughs at approximately 10 THz (approx. 500 K) implying diminishing numbers of available conformational states at higher temperatures; hence, fewer routes by which biochemical processes can be realized, as equilibrium is approached. Could this conformational bottleneck hinder the operation of biological macromolecules at higher temperatures? We suggest that the troughs at approximately 10 THz in absorbance spectra indicate that the hydrogen bonds, charge interactions and geometry of biological macromolecules associated with terrestrial life impose fundamental vibrational properties that could limit the upper temperature at which they may function.
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Affiliation(s)
- Kieran Hand
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Edwin Yates
- Department of Biochemistry, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
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49
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Miao X, Zhu J, Zhao K, Zhan H, Yue W. Determining the Humidity-Dependent Ortho-to- Para Ratio of Water Vapor at Room Temperature Using Terahertz Spectroscopy. Appl Spectrosc 2018; 72:1040-1046. [PMID: 29714077 DOI: 10.1177/0003702818772853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The origin of the water spin isomers observed under various physico-chemical conditions is of great interest, including that of H2O molecules in the gas phase. Here, terahertz time-domain spectroscopy (THz-TDS) was used to study the humidity-dependent ortho-to- para (O/P) ratio of water vapor at room temperature. The relative contents of para and ortho molecules were obtained by fitting the absorption lines of water vapor showing the relationship between the spin isomer contents and humidity. Larger O/P ratios with values of ∼3.2 were observed at lower humidity (<20%) due to the stronger attractive forces of para molecules. The concentration of the ortho isomers then began to decrease at higher humidity (>20%) due to the preferential formation of dimers and clusters at increasing concentrations. Thus, the ratio gradually decreased with increasing humidity.
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Affiliation(s)
- Xinyang Miao
- 1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Jing Zhu
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Kun Zhao
- 1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Honglei Zhan
- 2 Beijing Key Laboratory of Optical Detection Technology for Oil and Gas, China University of Petroleum, Beijing, China
| | - Wenzheng Yue
- 1 State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, China
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50
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Tsubouchi M, Nagashima K. High-Speed Terahertz Waveform Measurement for Intense Terahertz Light Using 100-kHz Yb-Doped Fiber Laser. Sensors (Basel) 2018; 18:E1936. [PMID: 29904000 DOI: 10.3390/s18061936] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/08/2018] [Accepted: 06/13/2018] [Indexed: 11/27/2022]
Abstract
We demonstrate a high-speed terahertz (THz) waveform measurement system for intense THz light with a scan rate of 100 Hz. To realize the high scan rate, a loudspeaker vibrating at 50 Hz is employed to scan the delay time between THz light and electro-optic sampling light. Because the fast scan system requires a high data sampling rate, we develop an Yb-doped fiber laser with a repetition rate of 100 kHz optimized for effective THz light generation with the output electric field of 1 kV/cm. The present system drastically reduces the measurement time of the THz waveform from several minutes to 10 ms.
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