Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5–10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°–60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators.

Precise Measurement of the e^{+}e^{-}→π^{+}π^{-}J/ψ Cross Section at Center-of-Mass Energies from 3.77 to 4.60 GeV

The cross section for the process e^{+}e^{-}→π^{+}π^{-}J/ψ is measured precisely at center-of-mass energies from 3.77 to 4.60 GeV using 9  fb^{-1} of data collected with the BESIII detector operating at the BEPCII storage ring. Two resonant structures are observed in a fit to the cross section. The first resonance has a mass of (4222.0±3.1±1.4)  MeV/c^{2} and a width of (44.1±4.3±2.0)  MeV, while the second one has a mass of (4320.0±10.4±7.0)  MeV/c^{2} and a width of (101.4_{-19.7}^{+25.3}±10.2)  MeV, where the first errors are statistical and second ones are systematic. The first resonance agrees with the Y(4260) resonance reported by previous experiments. The precision of its resonant parameters is improved significantly. The second resonance is observed in e^{+}e^{-}→π^{+}π^{-}J/ψ for the first time. The statistical significance of this resonance is estimated to be larger than 7.6σ. The mass and width of the second resonance agree with the Y(4360) resonance reported by the BABAR and Belle experiments within errors. Finally, the Y(4008) resonance previously observed by the Belle experiment is not confirmed in the description of the BESIII data.

Evidence of Two Resonant Structures in e^{+}e^{-}→π^{+}π^{-}h_{c}

The cross sections of e^{+}e^{-}→π^{+}π^{-}h_{c} at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The cross sections are found to be of the same order of magnitude as those of e^{+}e^{-}→π^{+}π^{-}J/ψ and e^{+}e^{-}→π^{+}π^{-}ψ(2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e^{+}e^{-}→π^{+}π^{-}h_{c} cross sections around 4.22 and 4.39  GeV/c^{2}, which we call Y(4220) and Y(4390), respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4_{-4.5}^{+5.5}±0.9)  MeV/c^{2} and a width of (66.0_{-8.3}^{+12.3}±0.4)  MeV for the Y(4220), and a mass of (4391.5_{-6.8}^{+6.3}±1.0)  MeV/c^{2} and a width of (139.5_{-20.6}^{+16.2}±0.6)  MeV for the Y(4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y(4220) and Y(4390) is 10σ over one structure assumption.

Amplitude Analysis of the Decays η^{'}→π^{+}π^{-}π^{0} and η^{'}→π^{0}π^{0}π^{0}

Based on a sample of 1.31×10^{9}  J/ψ events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays η^{'}→π^{+}π^{-}π^{0} and η^{'}→π^{0}π^{0}π^{0} is performed. A significant P-wave contribution from η^{'}→ρ^{±}π^{∓} is observed for the first time in η^{'}→π^{+}π^{-}π^{0}. The branching fraction is determined to be B(η^{'}→ρ^{±}π^{∓})=(7.44±0.60±1.26±1.84)×10^{-4}, where the first uncertainty is statistical, the second systematic, and the third model dependent. In addition to the nonresonant S-wave component, there is a significant σ meson component. The branching fractions of the combined S-wave components are determined to be B(η^{'}→π^{+}π^{-}π^{0})_{S}=(37.63±0.77±2.22±4.48)×10^{-4} and B(η^{'}→π^{0}π^{0}π^{0})=(35.22±0.82±2.54)×10^{-4}, respectively. The latter one is consistent with previous BESIII measurements.

Measurement of Singly Cabibbo Suppressed Decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}

Using 567  pb^{-1} of data collected with the BESIII detector at a center-of-mass energy of sqrt[s]=4.599  GeV, near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold, we study the singly Cabibbo-suppressed decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. By normalizing with respect to the Cabibbo-favored decay Λ_{c}^{+}→pK^{-}π^{+}, we obtain ratios of branching fractions: [B(Λ_{c}^{+}→pπ^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(6.70±0.48±0.25)%, [B(Λ_{c}^{+}→pϕ)/B(Λ_{c}^{+}→pK^{-}π^{+})]=(1.81±0.33±0.13)%, and [B(Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(9.36±2.22±0.71)×10^{-3}, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Λ_{c}^{+}→pπ^{+}π^{-} is observed for the first time, and the precision of the branching fraction for Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-} and Λ_{c}^{+}→pϕ is significantly improved.

Publisher's Note: Laser propagation in dense magnetized plasma [Phys. Rev. E 94, 053207 (2016)]

This corrects the article DOI: 10.1103/PhysRevE.94.053207.

Laser propagation in dense magnetized plasma

A right-hand circularly polarized electromagnetic wave can propagate in a sufficiently magnetized plasma of any density without encountering cutoff in the whistler mode. With the recent realization of tens-kilotesla magnetic fields, laser propagation in highly magnetized high-density plasmas has become of practical interest, especially for heating plasmas to high energy density and igniting fusion targets. In this paper, the whistler regime of laser-plasma interaction is discussed. It is shown by one- and two-dimensional particle-in-cell simulations that moderately intense right-hand circularly polarized laser light can enter and propagate in high-density plasma and heat it efficiently because of the significantly reduced wave length and speed.

[Current status of work-related musculoskeletal disorders in nurses in Xinjiang, China]

Objective: To investigate the prevalence of work-related musculoskeletal disorders (WMSDs) in nurses in Xinjiang, China, to analyze the influencing factors for the development of WMSDs, and to provide a reference for the prevention and treatment of WMSDs in nurses. Methods: Stratified cluster sampling was used to randomly select 8 422 nurses in 8 tertiary hospitals and 4 secondary hospitals in Xinjiang from January to October, 2015. A questionnaire survey was performed to investigate the prevalence of WMSDs in nurses from departments of internal medicine, surgery, gynecology, pediatrics, emergency, and intensive care and operating rooms and analyze related influencing factors. Results: A total of 3 000 questionnaires were distributed, and 2 851 questionnaires were returned, resulting in a recovery rate of 95.00%. In the nurses who participated in the survey, the prevalence of WMSDs was 78.58%. As for different body parts, the prevalence of WMSDs was 63.36% in the waist, 61.79% in the neck, 52.52% in the shoulder, 41.83% in the back, 35.56% in the knees, 33.35% in the ankles, 26.02% in the wrists, 23.41% in the hip, and 17.62% in the elbows. There were significant differences in the prevalence of WMSDs across the nurses with different ages and working years (χ²=28.29 and 27.73, both P<0.01) , and the prevalence of WMSDs tended to increase with the increasing age and working years (χ²=22.94 and 17.56, both P<0.01) . The results of multivariate logistic regression analysis showed that sex, working years, intensive care/emergency, outpatient service, surgical anesthesia, weekly working hours, physical condition, and fatigue in work were risk factors for WMSDs in nurses. Conclusion: In the nurses in Xinjiang, the prevalence of WMSDs in the neck, shoulder, back, and waist is high, and nurses with different ages, working years, departments, sexes, physical conditions, and weekly working hours have varying degrees of risk of WMSDs.

[Profiles of cognitive and language impairment of logopenic and non-fluent variant of primary progressive aphasia]

OBJECTIVE

To decipher the cognitive and linguistic feature of logopenic variant primary progressive aphasia (lv-PPA) and nonfluent variant primary progressive aphasia (nfv-PPA) and to explore the extent to which cognitive and language impairment contribute to the dysfunction of activity of daily living(ADL).

METHODS

Seven lv-PPA and five nfv-PPA were enrolled in memory clinic of Xuanwu Hospital, Capital Medical University from January 2015 to January 2016 accordig to the international consensus criteria for PPA and its three subtypes. 20 age-matched normal controls (NC) were included. Both the patients and the NC completed a battery of neuropsychological test, lingusitic test and brain magnetic resonance imaging. All the patients conducted (11)C Pittsburgh compound B (PiB) PET imaging.

RESULT

Lv-PPA patients were characterized by deficits in lexical retrieval and long sentenses repetition, while nfv-PPA were with motor speech apraxia and phonetic distortion. Compared with nfv-PPA, lv-PPA patient displayed more severe cognitive deficit with younger onset of age (56±5 vs 61±5, P<0.05) , rapid decline of MMSE score within 1.5 years and pariental cortex dysfunctions such as ideomotor praxis, Gerstmann syndrome and contructional apraxia. Correlation analysis indicated that there was more significant association between pariental cortex dysfunction and ADL/mini-mental state examination(MMSE) than that of language deficit(r=-0.868, r=-0.922; r=0.312, r=-0.257). All seven lv-PPA were PiB-PET positive and five nfv-PPA were negative.

CONCLUSION

This study enriched the chinical and linguistic characterization of lv-PPA and nfv-PPA, which has implication for diagnosis, disease management and treatment for clinicians.

Observation of an Anomalous Line Shape of the η^{'}π^{+}π^{-} Mass Spectrum near the pp[over ¯] Mass Threshold in J/ψ→γη^{'}π^{+}π^{-}

Using 1.09×10^{9} J/ψ events collected by the BESIII experiment in 2012, we study the J/ψ→γη^{'}π^{+}π^{-} process and observe a significant abrupt change in the slope of the η^{'}π^{+}π^{-} invariant mass distribution at the proton-antiproton (pp[over ¯]) mass threshold. We use two models to characterize the η^{'}π^{+}π^{-} line shape around 1.85  GeV/c^{2}: one that explicitly incorporates the opening of a decay threshold in the mass spectrum (Flatté formula), and another that is the coherent sum of two resonant amplitudes. Both fits show almost equally good agreement with data, and suggest the existence of either a broad state around 1.85  GeV/c^{2} with strong couplings to the pp[over ¯] final states or a narrow state just below the pp[over ¯] mass threshold. Although we cannot distinguish between the fits, either one supports the existence of a pp[over ¯] moleculelike state or bound state with greater than 7σ significance.

Observation of h_{c} Radiative Decay h_{c}→γη^{'} and Evidence for h_{c}→γη

A search for radiative decays of the P-wave spin singlet charmonium resonance h_{c} is performed based on 4.48×10^{8} ψ^{'} events collected with the BESIII detector operating at the BEPCII storage ring. Events of the reaction channels h_{c}→γη^{'} and γη are observed with a statistical significance of 8.4σ and 4.0σ, respectively, for the first time. The branching fractions of h_{c}→γη^{'} and h_{c}→γη are measured to be B(h_{c}→γη^{'})=(1.52±0.27±0.29)×10^{-3} and B(h_{c}→γη)=(4.7±1.5±1.4)×10^{-4}, respectively, where the first errors are statistical and the second are systematic uncertainties.

Compression Stockings for Prevention of Postthrombotic Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

The present meta-analysis aimed to evaluate the efficacy and safety of compression stockings for postthrombotic syndrome (PTS) prevention in patients with deep venous thrombosis (DVT).

METHODS

Randomized controlled trials (RCTs) regarding the use of compression stockings for prevention of PTS were identified from the Medline, PubMed, and Embase databases as well as the Cochrane library. The resulting manuscripts were analyzed according to the criteria in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Six RCTs involving 1465 patients with DVT were included. The meta-analysis indicated no statistical differences between the compression stocking and the control groups in PTS incidence, using either the Villalta scale (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.23-1.74) or the Ginsberg scale (OR, 1.13; 95% CI, 0.72-1.77). Based on the Villalta scale categorization, there were no differences in the incidence of mild-moderate PTS (OR, 0.71; 95% CI, 0.36-1.41) or incidence of severe PTS (OR, 0.68; 95% CI, 0.15-3.11). The difference in the recurrence of venous thromboembolism (OR, 0.89; 95% CI, 0.61-1.30) was also not significant. In the 3 RCTs that reported side effects of compression stockings, they were primarily related to discomfort, including itching, erythema, and rash.

CONCLUSION

The present meta-analysis has indicated that compression stockings may not prevent PTS, as determined by either the Villalta or the Ginsberg scale, in patients with DVT. However, owing to the limited number of trials, the evidence is not strong enough to draw a reliable conclusion. Further larger, randomized, double-blind, placebo-controlled, multicenter trials are needed.

[The pathogenic gene screening in a cardiomyopathy pedigree of Yunnan province]

OBJECTIVE

In this study, the sreening of candidate pathogenic gene is done among family members of an dilated cardiomyopathy(DCM)and hypertrophic cardiomyopathy (HCM) coexistence, and find the relationship between the genotype and the phenotype.

METHODS

The inheritance atlas was drawn, analysis of genetic characteristics and clinical phenotype.Peripheral venous blood samples of proband and family members were candidated gene exon high-throughput sequencing sub target capture, make the result compares with related database, ultimately screening the target area of the exon and mutations of candidate genes and then using bidirectional sequencing of Sanger to sequence other family members and the health group which were matching with gender and age to testify whether there is the above mutations.

RESULTS

In this family, the proband and his father carry three missense mutations, about TTNc.604 A>G(p.Lys202Glu)、TAZ c. 580A>G(p.Ile194Val)and MYH7c.730 T>C(p.Phe244Leu). The heart function of proband was failure, and accompanied malignant arrhythmia.But his father has no obvious clinical symptoms.In this family, the same genetic mutation of disease causing gene lead to different clinical phenotype, but different genetic mutation of disease causing gene lead to the same clinical phenotype.None of the mutations found in this family was found in the health group.

CONCLUSION

The patient of this family carries the genetic mutation of MYH7, TTN and TAZ.The patient of this family carries the composite mutation of MYH7(+) /TTN(+) heterozygous missense mutation and TAZ(+) /TTN(+) heterozygous missense mutation may be show the performance of the genetic characteristics of early onset, severe phenotype.

Observation of the Singly Cabibbo-Suppressed Decay D^{+}→ωπ^{+} and Evidence for D^{0}→ωπ^{0}

Based on 2.93  fb^{-1} e^{+}e^{-} collision data taken at center-of-mass energy of 3.773 GeV by the BESIII detector, we report searches for the singly Cabibbo-suppressed decays D^{+}→ωπ^{+} and D^{0}→ωπ^{0}. A double tag technique is used to measure the absolute branching fractions B(D^{+}→ωπ^{+})=(2.79±0.57±0.16)×10^{-4} and B(D^{0}→ωπ^{0})=(1.17±0.34±0.07)×10^{-4}, with statistical significances of 5.5σ and 4.1σ, where the first and second uncertainties are statistical and systematic, respectively.

Measurements of Absolute Hadronic Branching Fractions of the Λ_{c}^{+} Baryon

We report the first measurement of absolute hadronic branching fractions of Λ_{c}^{+} baryon at the Λ_{c}^{+}Λ[over ¯]_{c}^{-} production threshold, in the 30 years since the Λ_{c}^{+} discovery. In total, 12 Cabibbo-favored Λ_{c}^{+} hadronic decay modes are analyzed with a double-tag technique, based on a sample of 567  pb^{-1} of e^{+}e^{-} collisions at sqrt[s]=4.599  GeV recorded with the BESIII detector. A global least-squares fitter is utilized to improve the measured precision. Among the measurements for twelve Λ_{c}^{+} decay modes, the branching fraction for Λ_{c}^{+}→pK^{-}π^{+} is determined to be (5.84±0.27±0.23)%, where the first uncertainty is statistical and the second is systematic. In addition, the measurements of the branching fractions of the other 11 Cabibbo-favored hadronic decay modes are significantly improved.

Measurement of Azimuthal Asymmetries in Inclusive Charged Dipion Production in e^{+}e^{-} Annihilations at sqrt[s]=3.65 GeV

We present a measurement of the azimuthal asymmetries of two charged pions in the inclusive process e^{+}e^{-}→ππX, based on a data set of 62  pb^{-1} at the center-of-mass energy of 3.65 GeV collected with the BESIII detector. These asymmetries can be attributed to the Collins fragmentation function. We observe a nonzero asymmetry, which increases with increasing pion momentum. As our energy scale is close to that of the existing semi-inclusive deep inelastic scattering experimental data, the measured asymmetries are important inputs for the global analysis of extracting the quark transversity distribution inside the nucleon and are valuable to explore the energy evolution of the spin-dependent fragmentation function.

Observation of a Neutral Structure near the DD[over ¯]^{*} Mass Threshold in e^{+}e^{-}→(DD[over ¯]^{*})^{0}π^{0} at sqrt[s]=4.226 and 4.257 GeV

A neutral structure in the DD[over ¯]^{*} system around the DD[over ¯]^{*} mass threshold is observed with a statistical significance greater than 10σ in the processes e^{+}e^{-}→D^{+}D^{*-}π^{0}+c.c. and e^{+}e^{-}→D^{0}D[over ¯]^{*0}π^{0}+c.c. at sqrt[s]=4.226 and 4.257 GeV in the BESIII experiment. The structure is denoted as Z_{c}(3885)^{0}. Assuming the presence of a resonance, its pole mass and width are determined to be [3885.7_{-5.7}^{+4.3}(stat)±8.4(syst)]  MeV/c^{2} and [35_{-12}^{+11}(stat)±15(syst)]  MeV, respectively. The Born cross sections are measured to be σ[e^{+}e^{-}→Z_{c}(3885)^{0}π^{0},Z_{c}(3885)^{0}→DD[over ¯]^{*}]=[77±13(stat)±17(syst)]  pb at 4.226 GeV and [47±9(stat)±10(syst)]  pb at 4.257 GeV. The ratio of decay rates B[Z_{c}(3885)^{0}→D^{+}D^{*-}+c.c.]/B[Z_{c}(3885)^{0}→D^{0}D[over ¯]^{*0}+c.c.] is determined to be 0.96±0.18(stat)±0.12(syst), consistent with no isospin violation in the process, Z_{c}(3885)^{0}→DD[over ¯]^{*}.

Measurement of the Absolute Branching Fraction for Λ_{c}^{+}→Λe^{+}ν_{e}

We report the first measurement of the absolute branching fraction for Λ_{c}^{+}→Λe^{+}ν_{e}. This measurement is based on 567  pb^{-1} of e^{+}e^{-} annihilation data produced at sqrt[s]=4.599  GeV, which is just above the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold. The data were collected with the BESIII detector at the BEPCII storage rings. The branching fraction is determined to be B(Λ_{c}^{+}→Λe^{+}ν_{e})=[3.63±0.38(stat)±0.20(syst)]%, representing a significant improvement in precision over the current indirect determination. As the branching fraction for Λ_{c}^{+}→Λe^{+}ν_{e} is the benchmark for those of other Λ_{c}^{+} semileptonic channels, our result provides a unique test of different theoretical models, which is the most stringent to date.

Abstract 1541: Secreted serglycin in tumor microenvironment promotes tumor malignancies in a CD44-dependent manner

Tumor microenvironment (TME) plays an important role in cancer progression; however, the communication between TME and cancer cells remains largely unclear. CD44, a type I cell surface receptor functioning in cell-cell and cell-extracellular matrix interactions, has been implicated in tumor formation and progression. Using gain-of-function and loss-of-function approaches, we report in this study that serglycin (SRGN), a glycoprotein secreted from cancer-associated fibroblasts (CAFs) as well as aggressive cancer cells, works to promote the malignant behaviors of non-small cell lung cancer cells through its interaction with CD44. We showed that SRGN promotes cell transformation and tumor formation and metastasis using in vitro and in vivo tumorigenic assays. Furthermore, we showed that SRGN induced lung cancer cell stemness in a CD44-dependent manner. SRGN enhanced cancer cells sphere formation via Nanog induction, accompanied with increased drug resistance and resistance to anoikis. We also demonstrated that SRGN promotes cell migratory activity through promoting epithelial-mesenchymal transition (EMT) and enhancing adhesions turnover by upregulating vimentin expression and SRC activity via CD44/NF-KB/Claudin-1 axis. In support, Claudin-1 expression was tightly associated with SRGN expression in primary lung cancer tissues (p &lt; 0.0001). In summary, we demonstrate that the crosstalk between tumor cells and TME promotes malignant phenotypes through the interaction of tumor-borne CD44 and CAF- or tumor-derived SRGN, suggesting that targeting CD44 or its ligands may represent an attractive strategy for development of cancer therapy.

Citation Format: Jing-You Guo, Shiaw-Wei Tyan, Han-Shui Hsu, Fen-Yau Li, Jeou-Yuan Chen. Secreted serglycin in tumor microenvironment promotes tumor malignancies in a CD44-dependent manner. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1541. doi:10.1158/1538-7445.AM2015-1541

Radially polarized, half-cycle, attosecond pulses from laser wakefields through coherent synchrotronlike radiation

Attosecond bursts of coherent synchrotronlike radiation are found when driving ultrathin relativistic electron disks in a quasi-one-dimensional regime of wakefield acceleration, in which the laser waist is larger than the wake wavelength. The disks of overcritical density shrink radially due to focusing wakefields, thus providing the transverse currents for the emission of an intense, radially polarized, half-cycle pulse of about 100 attoseconds in duration. The electromagnetic pulse first focuses to a peak intensity (7×10(20)W/cm(2)) 10 times larger than the driving pulse and then emerges as a conical beam. Basic dynamics of the radiative process are derived analytically and in agreement with particle-in-cell simulations. By making use of gas targets instead of solids to form the ultrathin disks, this method allows for high repetition rates required for applications.

Dense attosecond electron sheets from laser wakefields using an up-ramp density transition

Controlled electron injection into a laser-driven wakefield at a well defined space and time is reported based on particle-in-cell simulations. Key novel ingredients are an underdense plasma target with an up-ramp density profile followed by a plateau and a fairly large laser focus diameter that leads to an essentially one-dimensional (1D) regime of laser wakefield, which is different from the bubble (complete blowout) regime occurring for tightly focused drive beams. The up-ramp profile causes 1D wave breaking to occur sharply at the up-ramp-plateau transition. As a result, it generates an ultrathin (few nanometer, corresponding to attosecond duration), strongly overdense relativistic electron sheet that is injected and accelerated in the wakefield. A peaked electron energy spectrum and high charge (∼nC) distinguish the final sheet.

Primary congenital pulmonary hypoplasia of a neonate

Pulmonary hypoplasia is a rare but usually lethal disease. We report a full-term male neonate who presented with respiratory failure immediately after birth. Chest X-ray revealed a small lung volume despite advanced ventilator support. Respiratory failure persisted and this baby died at 40.5 hours of age. The autopsy showed a lung-to-birth weight ratio of 0.69% and a radial alveoli count of 2.97. All this information confirmed the diagnosis of primary congenital pulmonary hypoplasia.

Superconductivity above 33 K in (Ca(₁ - x)Na(x))Fe₂As₂

We report the synthesis of (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ showing a superconducting transition with T(c) above 33 K. Both dc magnetic susceptibility or specific heat measurements indicated the bulk superconductivity nature of the sample. We also have successfully grown single crystals of the (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ superconductors. The single crystals exhibit sharp superconducting transitions with T(c) above 33 K. The effects of magnetic field on the superconducting transitions are studied, giving rise to high upper critical fields with H(c₂)(c)≈85 T and H(c₂)(ab)≈172 T, respectively. The anisotropy parameter was calculated to be around 2.

Preparation of xanthated bentonite and its removal behavior for Pb(II) ions

Xanthate was successfully grafted onto bentonite by a relatively simple solution reaction. The obtained xanthated bentonite (XBent) was characterized by FT-IR spectrophotometer, thermogravimetric analysis (TG), particle size analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM). XBent acting as a type of environmentally friendly adsorbent was applied to remove lead ions from aqueous solutions. The optimum conditions were as follows: [Pb(2+)] = 500 mg L(-1), [XBent] = 2 g L(-1), pH = 5.0; oscillating 60 min under 200 rpm at 25 degrees C. The removal rate of lead was up to 99.9%. It was found that the lead(II) ions-XBent adsorption isotherm model fitted well to the Freundlich isotherm. The adsorption mechanism was also investigated by SEM and XRD, which concluded that lead ions were complexed or chelated with XBent. XBent appears to have potential to be used later in water treatment as a type of inorganic polymer reagent.

Preparation of solid composite polyferric sulfate and its flocculation behavior for wastewater containing high concentration organic compounds

A new kind of inorganic polymer flocculant, the solid composite polyferric sulfate (SPFS) was prepared using ferrous sulfate and Na-Bentonite. The obtained SPFS was characterized by FT-IR spectra, thermogravimetric analysis (TG), scanning electron microscope (SEM) and X-ray Diffraction (XRD). It showed that SPFS was a kind of composite inorganic polymer, which was the complex of PFS and Na-Bent, not only a simple mixture of raw materials. The synthetic mechanism and surface structure of SPFS were also discussed. Acting as a kind of environment-friendly flocculating agent, the solid composite polyferric sulfate (SPFS) was applied in pretreatment of potato starch industry wastewater, a typical wastewater containing high concentration organic compounds, which COD was above 6,000 mg/L. The results showed that the COD removal value reached 4,070 mg/L with COD removal rates being 46.6%. Based on these results, it is suggested that the SPFS can be attractive pretreatment agent for the starch industry wastewater.