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Yuan HK, Cui H, Liu B, Tian CL, Kuang AL, Chen H. Density functional theory calculations for magnetic properties of Co 3W systems. J Chem Phys 2018; 149:014303. [PMID: 29981542 DOI: 10.1063/1.5029398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cheaper permanent magnetic nanostructures with magnetic properties equivalent to those of noble-metal or rare-earth nanomagnets have been experimentally developed for their potential applications in ultrahigh storage densities in magnetic memory. To date, their intrinsic magnetic properties are not well understood under the micro-level of local atomic arrangements and electronic structures. In this work, we performed theoretical investigations on the Co3W bulk, the clean surface, nanoclusters, and the Co|Co3W bilayers and superlattices for their geometrical structures, magnetic moments, and magnetic anisotropy energies (MAEs). We found that the Co3W nanostructures we constructed are stable and have the local minima in the energetic landscape, whose stabilities increase with increasing proportion of W and cluster size. The Co and W atoms in clusters are antiferromagnetically coupled, and their local magnetic moments decrease with increasing proportion of W. The breakdown of the Hund's third rule in W atoms observed in experiment can be interpreted as the competition between the intra-atomic spin-orbit coupling in W atoms and interatomic Co-W hybridizations. The highest MAE of about a few tens of meV is obtained in small cluster sizes, whereas it is an order of magnitude reduction in large cluster sizes. The magnetic systems of Co3W clean surface, Co|Co3W bilayer and superlattice can present large MAEs, and their easy-axes of magnetization are perpendicular to the (001) surface. Our calculated MAEs are of the same order of magnitude as that of the experimental measurements, and the electronic origin is revealed through the second-order perturbation method.
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Affiliation(s)
- H K Yuan
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - H Cui
- School of Mechanical Engineering, Shaanxi University of Technology, Hanzhong, Shaanxi 723001, People's Republic of China
| | - B Liu
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - C L Tian
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - A L Kuang
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - H Chen
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
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Yuan HK, Cui H, Liu B, Tian CL, Wang JZ, Kuang AL, Chen H. Magnetic moment and magnetic anisotropy of Ge 3Mn 5 thinfilms on Ge(111) substrate: A density functional study. J Chem Phys 2018; 148:074701. [PMID: 29471644 DOI: 10.1063/1.5006535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Magnetism and magnetic anisotropy energy (MAE) of the Ge3Mn5 bulk, free-standing surface, and Ge3Mn5(001)|Ge(111) thinfilms and superlattice have been systemically investigated by using the relativistic first-principles electronic structure calculations. For Ge3Mn5 adlayers on Ge(111) substrates within Mn1 termination, the direction of magnetization undergoes a transition from in-plane at 1 monolayer (ML) thickness (MAE = -0.50 meV/ML) to out-of-plane beginning at 3 ML thickness (nearly invariant MAE = 0.16 meV/ML). The surficial/interfacial MAE is extracted to be 1.23/-0.54 meV for Mn1-termination; the corresponding value is 0.19/1.03 meV for Mn2/Ge-termination; the interior MAE is averaged to be 0.09 meV per ML. For various Ge3Mn5 systems, the in-plane lattice expansion and/or interlayer distance contraction would enhance the out-of-plane MAE. Our theoretical magnetic moments and MAEs fit well with the experimental measurements. Finally, the origination of MAE is elucidated under the framework of second-order perturbation with the electronic structure analyses.
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Affiliation(s)
- H K Yuan
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - H Cui
- School of Mechanical Engineering, Shaanxi University of Technology, Shanxi 723001, People's Republic of China
| | - B Liu
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - C L Tian
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - J Z Wang
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - A L Kuang
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
| | - H Chen
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
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Kou CY, Zhuang L, Wang GQ, Cui H, Yuan HK, Tian CL, Wang JZ, Chen H. [TM13@Bi20]− clusters in three-shell icosahedral matryoshka structure: being as superatoms. RSC Adv 2015. [DOI: 10.1039/c5ra19194g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Using the density functional theory (DFT) method, three-shell icosahedral matryoshka [TM13@Bi20]− clusters (TM = 3d, 4d) have been systematically examined to explore the possibility of clusters being as superatoms.
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Affiliation(s)
- C. Y. Kou
- School of Physical Science and Technology
- Southwest University
- Chongqing
- People's Republic of China
| | - L. Zhuang
- School of Physical Science and Technology
- Southwest University
- Chongqing
- People's Republic of China
| | - G. Q. Wang
- College of Arts and Science
- Shanxi Aviation Professional Technical Institute
- Hanzhong
- People's Republic of China
| | - H. Cui
- School of Automation and Information Engineering
- Xi'an University of Technology
- Xi'an 710048
- People's Republic of China
| | - H. K. Yuan
- School of Physical Science and Technology
- Southwest University
- Chongqing
- People's Republic of China
| | - C. L. Tian
- School of Physical Science and Technology
- Southwest University
- Chongqing
- People's Republic of China
| | - J. Z. Wang
- School of Physical Science and Technology
- Southwest University
- Chongqing
- People's Republic of China
| | - H. Chen
- School of Physical Science and Technology
- Southwest University
- Chongqing
- People's Republic of China
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Ren ZH, Yuan W, Deng HD, Deng JL, Dan QX, Jin HT, Tian CL, Peng X, Liang Z, Gao S, Xu SH, Li G, Hu Y. Effects of antibacterial peptide on cellular immunity in weaned piglets. J Anim Sci 2014; 93:127-34. [PMID: 25403191 DOI: 10.2527/jas.2014-7933] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [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: 11/13/2022] Open
Abstract
The aim of this study was to evaluate the effects of antibacterial peptide (ABP) sufficiency on cellular immune functions by determining the spleen cell cycle and apoptosis, peripheral blood T cell subsets, and T cell proliferation function in weaned piglets. A total of 90 piglets (Duroc × Landrace × Yorkshire) of both sexes were randomly allotted to 5 dietary treatments. Each treatment consisted of 3 replicates with 6 piglets per replicate. The dietary treatments consisted of the negative control (NC; basal diet), positive control (PC; basal diet supplemented with 400 mg/kg Astragalus polysaccharide), and ABP (basal diet mixed with 250, 500, and 1,000 mg/kg ABP). The experimental lasted for 28 d. Two piglets from each replicate were selected randomly for blood samples extraction from the jugular vein to obtain peripheral blood T cell subsets, and T cell proliferation function analysis was performed on d 32, 39, 46, and 53. Two piglets from each replicate were selected and euthanized to observe the spleen cell cycle and apoptosis on d 39 and 53. In ABP-sufficient piglets, the G0/G1 phase of the spleen cell cycle was much lower (P < 0.05) and the S and G2 + M phases and proliferation index (PI) were greater (P < 0.05) than in NC piglets. The percentage of apoptotic cells in the spleen significantly decreased under ABP sufficiency (P < 0.05). The proliferation function of peripheral blood T cells increased (P < 0.05) in ABP-sufficient piglets. Percentages of CD3 (+) and CD3 (+)CD4 (+) ratios (d 39, 46, and 53) and CD4 (+)CD8 (+) ratios (d 32, 39, 46, and 53) increased remarkably (P < 0.05) under ABP sufficiency compared with NC. These results suggest that ABP sufficiency could increase the T cell population and proliferation function of T cells and could induce decreased percentages of apoptotic cells. Overall, the cellular immune function was evidently improved in weaned piglets. We suggest optimal dosages of 500 mg/kg ABP for 4-wk addition and 1,000 mg/kg ABP for 2-wk addition.
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Affiliation(s)
- Z H Ren
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - W Yuan
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - H D Deng
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - J L Deng
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - Q X Dan
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - H T Jin
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - C L Tian
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - X Peng
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - Z Liang
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - S Gao
- Department of Veterinary Medicine, Sichuan Agricultural University, Yaan, Sichuan 625014, China
| | - S H Xu
- Qianxing Veterinary Pharmaceutical Co., Ltd, Chengdu, Sichuan 610000, China
| | - G Li
- Rota Bioengineering Co., Ltd., Chengdu, Sichuan 610000, China
| | - Y Hu
- Rota Bioengineering Co., Ltd., Chengdu, Sichuan 610000, China
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Yuan HK, Chen H, Tian CL, Kuang AL, Wang JZ. Density functional calculations for structural, electronic, and magnetic properties of gadolinium-oxide clusters. J Chem Phys 2014. [DOI: 10.1063/1.4871410] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Abstract
Using the density functional theory (DFT) under both frameworks of the local density approximation (LDA) and the generalized gradient approximation (GGA), we show that the anomalous magnetic moment of Tbn (n = 2-20, 22, 33) clusters found in recent experiment [J. Appl. Phys. 2010, 107, 09B526] is due to the antiferromagnetic or ferromagnetic couplings between Tb atoms in clusters. The local spin magnetic moment of Tb atoms is in the range 5.1-5.7 μ(B), which is faintly influenced by the cluster sizes, geometrical structures, and spin arrangements. Emphasis is made on the Tb13 cluster to eliminate the large magnetic discrepancy between the experiment and calculation. Geometrical evolution shows that the square-antiprism motif with one centered atom is competitive with the icosahedral motif for small Tb clusters n = 9-12, whereas the close packed icosahedral growth is clearly favored for large clusters n = 13-20, 22, 33. The clusters containing 4, 7, 10, 13, and 19 atoms are found to be more stable than their neighboring sizes, in agreement with the early mass spectral measurements. The electronic properties including the HOMO-LUMO energy gaps, ionization potentials, electron affinities, and electric dipole moments are calculated, and more importantly, the variational trends of the magnetic moment and electric dipole moment qualitatively fit well with the experimental observations.
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Affiliation(s)
- G L Zhang
- School of Physical Science and Technology, Southwest University , Chongqing 400715, People's Republic of China
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Abstract
Theoretical understanding of the stability, ferromagnetism, and spin polarization of Mn5Ge3 clusters has been performed by using the density functional theory with generalized gradient approximation for exchange and correlation. The magnetic moments and magnetic anisotropy energy (MAE) have been calculated for both bulk and clusters, and the enhanced magnetic moment as well as the enlarged MAE have been identified in clusters. The most attractive achievement is that Mn5Ge3 clusters show a fine half-metallic character with large energy scales. The present results may have important implications for potential applications of small Mn5Ge3 clusters as both emerging spintronics and next-generation data-storage technologies.
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Affiliation(s)
- H K Yuan
- School of Physical Science and Technology, Southwest University, Chongqing 400715, People's Republic of China
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Ma YY, Kawata S, Yu TP, Gu YQ, Sheng ZM, Yu MY, Zhuo HB, Liu HJ, Yin Y, Takahashi K, Xie XY, Liu JX, Tian CL, Shao FQ. Electron bow-wave injection of electrons in laser-driven bubble acceleration. Phys Rev E Stat Nonlin Soft Matter Phys 2012; 85:046403. [PMID: 22680582 DOI: 10.1103/physreve.85.046403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Indexed: 06/01/2023]
Abstract
An electron injection regime in laser wake-field acceleration, namely electron bow-wave injection, is investigated by two- and three-dimensional particle-in-cell simulation as well as analytical model. In this regime electrons in the intense electron bow wave behind the first bubble catch up with the bubble tail and are trapped by the bubble finally, resulting in considerable enhancement of the total trapped electron number. For example, with the increase of the laser intensity from 2 × 10(19) to 1 × 10(20) W/cm(2), the electron trapping changes from normal self-injection to bow-wave injection and the trapped electron number is enhanced by two orders of magnitude. An analytical model is proposed to explain the numerical observation.
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Affiliation(s)
- Y Y Ma
- College of Science, National University of Defense Technology, Changsha 410073, China.
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Cui RT, Huang XS, Shi Q, Tian CL, Liu JX, Pu CQ. POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes) syndrome in China. Intern Med J 2010; 41:481-5. [DOI: 10.1111/j.1445-5994.2010.02172.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Zhou Y, Deng ZC, Liu ZT, Yi J, Tang YW, Gao BY, Tian CL, Li YG, Ding XT. A new multichannel interferometer system on HL-2A. Rev Sci Instrum 2007; 78:113503. [PMID: 18052470 DOI: 10.1063/1.2805193] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A new multichannel HCN interferometer has been developed on HL-2A tokamak, which is characterized by two techniques: (1) the wave-guide HCN laser with cavity length of 6 m to increase the optical resource power and (2) high response room temperature waveguide Schottky diode detectors to obtain good beat signal. The space resolution is 7 cm by the use of focusing metal mirrors mounted on the vacuum chamber and a compensated optical system. In the 2006 experiment campaign, this new interferometer has been applied for plasma density profile and density sawtooth measurement.
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Affiliation(s)
- Y Zhou
- Southwestern Institute of Physics, Chengdu 610041, China
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Liu ZH, Li JL, Li N, Tian CL, Zhang KG. Effect of tetrandrine on morphine dependence in isolated guinea pig ileum. Zhongguo Yao Li Xue Bao 1999; 20:1000-4. [PMID: 11270964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
AIM To evaluate the effects of tetrandrine (Tet) and nimodipine (Nim) on the morphine (Mor) withdrawal response in the isolated guinea pig ileum. METHODS The withdrawal contracture was elicited by addition of naloxone (Nal) (1 mumol.L-1) to the isolated naive ileum incubated with Mor (3 mumol.L-1) at 37.5 degrees C for 4 h or to the ileum obtained from Mor-dependent guinea pig. RESULTS When Nim (0.01, 0.05, and 0.1 mumol.L-1) or Tet (1, 10, and 50 mumol.L-1) was added 1 min before Nal in the naive ilea bathed in Krebs solution containing Mor, or when the ilea from Mor-dependent guinea pigs were incubated with Nim (0.01, 0.05, and 0.1 mumol.L-1) or Tet (1, 10, and 50 mumol.L-1) for 15 min, or when Nim (5 and 10 mg.kg-1, i.p.) or Tet (15 and 30 mg.kg-1, i.p.) was administered in vivo to Mor-dependent guinea pigs, the Nal-precipitated withdrawal contracture was significantly decreased in a dose-dependent manner. CONCLUSION Tet and Nim, Ca2+ channel blockers, could inhibit the Nal-precipitated Mor withdrawal response in the isolated guinea pig ileum.
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Affiliation(s)
- Z H Liu
- Department of Pharmacology, Binzhou Medical College, Binzhou 256603, China
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Tian CL, Hetherington VJ, Reed S. A review of pyrolytic carbon: application in bone and joint surgery. J Foot Ankle Surg 1993; 32:490-8. [PMID: 8252007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The authors review pyrolytic carbon as a biomaterial. Its potential applications in bone and joint surgery are discussed. This manuscript includes work performed in the early 1980s through present day research.
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Affiliation(s)
- C L Tian
- Orthopedic Department, Jilin Central Hospital, Peoples Republic of China
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