(+)-N-对甲苯磺酰-L-谷氨酸和1，3-联(4-吡啶基)丙烷构筑的银(I)配位聚合物的合成、晶体结构及性质研究

以手性配体(+)-N-对甲苯磺酰-L-谷氨酸(H2tsgluO)和1,3-联(4-吡啶基)丙烷(bpp)与银盐反应合成了一种同手性的配合物{Ag(HtsgluO)(bpp)}n(1),对其进行了表征。X-射线单晶衍射测定表明,该配合物属单斜晶系,P21空间群,a=1.220 79(18)nm,b=1.034 49(16)nm,c=2.059 5(3)nm,β=96.006(2)°,V=2.586 7(7)nm3,Z=4,R1=0.060 2,银离子处于扭曲的四面体配位环境中,分别和1个HtsgluO-氧原子,2个bpp氮原子以及1个银离子配位。配合物通过银银键构成了二维层状结构,并且进一步通过氢键构成了三维超分子结构。此外,对配合物的热重和荧光性质进行了研究。     

高性能Bi3+掺杂改性PbO2电极的制备及表征

采用电沉积法制备了金属Bi3+改性PbO2(Bi-PbO2)电极,并通过扫描电镜(SEM)、X射线能谱(EDS)、X射线光电子能谱(XPS)、X射线衍射(XRD)、紫外-可见漫反射(UV-VisDRS)、荧光光谱(FP)、莫特-肖特基(Mott-Schottky)曲线、电化学阻抗谱(EIS)和线性极化扫描(LSV)等方法表征了其微结构和电化学性能.SEM、EDS和XPS结果表明,Bi3+以Bi2O3的形式掺杂进入PbO2镀层,同时其掺杂改性可明显改善PbO2镀层的微结构,使电极表面颗粒细化;XRD和UV-VisDRS分析结果显示Bi3+掺杂改性后,PbO2晶体的晶胞参数发生变化,同时禁带宽度(Eg)变小;荧光光谱分析表明Bi-PbO2电极可促进羟基自由基的产生,增强电极降解有机物的催化活性;电化学性能测试显示,Bi3+改性PbO2电极电催化活性的提升与电极的平带电势(Efb)负移、活性表面积增大、电化学反应电阻减小和析氧电位提高有关.     

Phase diagram of the frustrated spin ladder with the next nearest intrachain couplings

By the density matrix renormalization group method, the phase diagram of the frustrated spin-1/2 ladder with the next nearest intrachain and ferromagnetic interchain couplings is obtained. According to our results, the two-rung entanglement is shown to be more sensitive than order parameters for determining phase boundary in such a frustrated spin ladder model. Furthermore, the additional next nearest intrachain coupling is found to enhance the intermediate columnar dimerized phase evidently.     

胆固醇对磷脂酰乙醇胺单分子层影响的研究

利用LB技术对表面压力-面积(π-A)曲线进行了测量及原子力显微镜(AFM)观测,研究了胆固醇对磷脂酰乙醇胺单分子层的影响。π-A曲线分析表明,随着胆固醇的增加,加速了相变的发生,促进膜稳定状态的形成。AFM观察结果表明,随着胆固醇比例的增加,混合膜呈现从点状结构向较大的片状与网状共存结构的转化,最终纯胆固醇形成高度紧密的膜结构。     

Mo-X(B, C, N, O, F)共掺杂TiO2体系的光催化协同效应研究

采用密度泛函理论平面波超软赝势方法, 计算并分析了Mo/X(B, C, N, O, F)共掺杂TiO₂体系的形成能、电子结构和光学性质, 研究了共掺杂协同效应对于计算体系光催化性能的影响机制. 首先计算出不同掺杂体系的态密度及能带结构, 利用能带理论分析了共掺杂效应对于禁带宽度的调控作用, 进而分析了共掺杂对TiO₂光催化能力和稳定性的协同作用. 结合电荷密度图, 分析原子间的电荷转移情况, 得到计算体系中各原子成键状态. 最后, 结合光吸收谱线分析得出Mo/C共掺杂类型在调制TiO₂体系中可见光波段的光催化性能上优势明显, 在催化作用上表现出协同效应. 本文的理论研究对共掺杂方法在TiO₂光催化领域有着一定的指导意义.     

Low temperature testing and neutron irradiation of a swept charge device on board the HXMT satellite

We present the low temperature testing of an SCD detector, investigating its performance such as readout noise, energy resolution at 5.9 keV and dark current. The SCD's performance is closely related to temperature, and the temperature range of -80 ℃ to -50 ℃ is the best choice, where the FWHM at 5.9 keV is about 130 eV. The influence of the neutron irradiation from an electrostatic accelerator with fluence up to 1×10⁹ cm^-2 has been examined. We find the SCD is not vulnerable to neutron irradiation. The detailed operations of the SCD and the test results of low temperature are reported, and the results of neutron irradiation are discussed.     

Cuprous oxide nanoparticles dispersed on reduced graphene oxide as an efficient electrocatalyst for oxygen reduction reaction

Cuprous oxide (Cu(2)O) nanoparticles dispersed on reduced graphene oxide (RGO) were prepared by reducing copper acetate supported on graphite oxide using diethylene glycol as both solvent and reducing agent. The Cu(2)O/RGO composite exhibits excellent catalytic activity and remarkable tolerance to methanol and CO in the oxygen reduction reaction.     

Advances in zebrafish high content and high throughput technologies

The zebrafish has emerged as an excellent transitional screening model system between cell-based assays, which are rapid and inexpensive but have limited physiological relevance, and higher vertebrate models, which have better physiological relevance, but are more time-consuming and expensive to deploy. As vertebrates, zebrafish maintain significant evolutionary proximity to humans and have been validated as robust models for drug research, studies of mechanism and behavioral genetics. Unlike higher vertebrate models, zebrafish are well-suited to high-throughput applications owing to their high fecundity, rapid extrauterine development and transparency during organogenesis enabling in vivo labeling and imaging. Recent advances have been made in automating high content and high-throughput zebrafish screens, with the goal of developing fully automated drug screening platforms. The application and continued development of these technologies holds potential clinical significance in drug discovery and elucidating disease mechanisms.     

Coupling characteristics of high birefringence dual-core As2S3 rectangular lattice photonic crystal fiber

A type of As2S3 chalcogenide glass mid-infrared dual-core photonic crystal fiber has been proposed.The dualcore photonic crystal fiber(PCF) consists of two asymmetric cores.The high polarization property and the coupling characteristics have been studied by using the finite element method and mode coupling theory.Numerical results show that the birefringence at wavelength λ = 10 μm is up to 0.01386 and the coupling length can reach wavelength λ = 5 μm,261 μm and 271.44 μm for x-polarized mode and y-polarized mode,respectively.It demonstrates that a 6.786-mm-long fiber can exhibit an extinction ratio of better than 10 dB and a bandwidth of 180 nm.     

Comparison of the formation epitaxial graphenes on Si- and process and properties of C-face 6H-SiC substrates

In this paper,the epitaxial graphene layers grown on Si-and C-face 6H-SiC substrates are investigated under a low pressure of 400 Pa at 1600 C.By using atomic force microscopy and Raman spectroscopy,we find that there are distinct differences in the formation and the properties between the epitaxial graphene layers grown on the Si-face and the C-face substrates,including the hydrogen etching process,the stacking type,and the number of layers.Hopefully,our results will be useful for improving the quality of the epitaxial graphene on SiC substrate.