Helical Shell Structures of Ni-A1 Alloy Nanowires and Their Electronic Transport Properties

Six kinds of Ni-A1 alloy nanowires are optimized by means of simulated annealing. The optimized structures show that the Ni-A1 alloy nanowires are helical shell structures that are wound by three atomic strands, which is very similar to the case with pure metallic nanowires. The densities of states （DOS）, transmission function T（ E）, current-voltage （I - V） curves, and the conductance spectra of these alloy nanowires are also investigated. Our results indicate that the conductance spectra depend on the geometric structure properties and the ingredients of the alloy nanowires. We observe and study the nonlinear contribution to the I-V characteristics that are due to the quantum size effect and the impurity effect. The addition of Ni atoms decreases the conductance of the Ni-A1 alloy nanowire because the doping atom Ni change the electronic band structures and the charge density distribution. The interesting statistical results shed light on the physics of quantum transport at the nano-scale.     

First-principles study of structural,electronic and optical properties of orthorhombic SrZrO3

We have investigated the structural parameters, electronic structure and optical properties of orthorhombic SrZrO₃ using the plane-wave ultrasoft pseudopotential technique based on the first-principles density-functional theory (DFT). Our calculated structural parameters are in good agreement with the previous theoretical and experimental data. Band structure, density of states and chemical bonding have been systematically studied. Furthermore, the complex dielectric function, refractive index, extinction coefficient, optical reflectivity, absorption coefficient, loss function and optical conductivity are calculated, which show an optical anisotropy in the components of polarization directions (100), (010) and (001).     

Stachyodin A,a pterocarpan derivative with unusual spirotetrahydrofuran ring from the roots of Indigofera stachyodes

Stachyodin A (1), a rearrangement product of pterocarpan featuring a 6/5/5/6 tetracyclic ring system with an unusual spirotetrahydrofuran ring, and stachyodin B (2), a new dihydrochalcone, along with five known analogues (3–7) were isolated from the roots of Indigofera stachyodes. The structures of 1 and 2 were elucidated on the basis of their HRESIMS and NMR spectroscopic data, and their absolute configurations were determined by X-ray crystallographic analysis and electronic circular dichroism (ECD) data, respectively. Compounds 2–4 showed inhibition of nitric oxide production in lipopolysaccharide-activated BV-2 microglial cells.     

葛根素与乙酰胆碱酯酶作用的分子动力学模拟

旨在阐明葛根素与乙酰胆碱酯酶(AChE)的分子作用机制,并为基于葛根素的类似物的AChE抑制剂的研发提供参考.运用AutoDock 4.2进行葛根素与AChE的分子对接,采用YASARA进行分子动力学模拟,利用MMPBSA.py模块计算复合体系的结合自由能,分析氨基酸的能量贡献.结果显示,葛根素与AChE对接体系含有4个氢键,2个π-π键. 5 ns后,体系均方根偏差(RMSD)趋于平衡,体系结合自由能为-18.19 kcal/mol.促体系结合的主要作用力是范德华力、静电作用力,非溶剂化能是主要的结合阻力.能量贡献最大的残基依次为Asn533、Lys530、Ala534、Pro529.这些研究为新型抑制剂的研发提供理论参考.     

Ag3PO4的可见光光催化性能及机理分析

采用沉淀置换法制备了可见光光催化剂Ag3PO4,利用XRD、UV-Vis及XPS等对其进行了结构特性分析,以水中微污染有机物的降解评价了Ag3PO4的光催化活性,并通过活性物种及能带结构的分析对催化剂的光催化机理进行了推测。结果表明,Ag3PO4的带隙能约为1.9 eV、催化剂表面存在的Ag+可捕获光生e-、催化剂的价带电位较低,这有利于Ag3PO4在可见光照射下产生的e--h+的分离及活性物种.OH的形成。经60 min可见光光催化反应,15 mg.L-1的甲基橙和腐殖酸的降解率分别达97%和82%,比同等条件下TiO2-P25的降解率还高40%和25%,光催化剂Ag3PO4的用量为0.6 g.L-1。     

氧电极在光电催化降解水中苯酚的性能

以乙炔黑、活性炭、石墨粉与适量的Mn(NO3)2为原料,采用热压法制备氧电极,将其应用于光电催化降解水中苯酚的研究。采用BET、X射线衍射(XRD)及扫描电镜分析(SEM)测试技术对氧电极进行了表征,并考察了氧电极的制备条件对电极光电催化性能的影响,比较了铜片、镍片、氧电极3种不同阴极对苯酚的降解效果,也比较了相同操作条件下吸附、光催化、电催化、光电催化等过程对苯酚降解效果的影响。结果表明,氧电极的比表面积较大,主要晶相为石墨、Mn3O4,电极表面和内部的物料混合及气孔分布比较均匀;电极的较佳制备条件为:石墨、乙炔黑与活性炭的质量比1∶1∶1,烧结温度400℃,电极厚度1.0 mm;在降解水中苯酚的过程中,氧电极与光阳极能产生良好的光电协同效应,提高了水中苯酚的矿化率。     

新型复合膜优先透醇性能的研究

有机物优先透过膜不仅可以用于有机物的浓缩和回收,还可以用于污水的净化等,因而有机物优先透过型渗透蒸发膜的研究倍受重视^[1].但由于透醇型膜的研究起步较晚,以及膜材料选择和膜制备等诸多原因,致使透醇膜的研究进展缓慢.     

The Production of Monoclonal Antibody to Androstenedione and the Effect of Passive Immunization on Xinjiang Fine-Wool Sheep With It

Five hybridomas stably secreting monoclonal antibodies (McAbs) to androstenedione were prepared by using artificially synthesized androstenedione-11α-succinyl conjugate with bovine serum albumin (BSA) as antigen. These McAbs showed slightly high cross-reactivity with testosterone (8.1—12.3%) and estrone (0.8—2.5%) and high affinities ranging from 2.0×10~7 to 2.8×10~8 L/M. They were all of the IgG_1 subclass. Xinjiang finewool ewes which were passively immunized with McAbs had higher circulating levels of progesterone (P) and luteinizing hormone (LH) than those of control ewes in two oestrous cycles and these changes led to increased ovulation rate and twin lambs born in young ewes.     

Realizing fast photoinduced recovery with polyfluorene-block-poly(vinylphenyl oxadiazole) block copolymers as electret in photonic transistor memory devices

Photonic field-effect transistor (FET) memory devices offer unique advantages owing to their solution processability, low cost production, and their lightweight and structural flexibility. Despite the plethora of research demonstrated the photon based programming process, limited reports are available for photoinduced recovery mechanism in such devices. To investigate the influence of polymer electret design on photonic memory performance, poly(9,9-dioctylfluorene) (PFO)–block–poly (vinylphenyl oxadiazole) (POXD) conjugated block copolymers were employed to a photonic FET memory with n-type semiconducting channel. The studied device exhibited bistable ON/OFF current states after electrical programming and photoinduced recovery (erasing) processes. The device operating mechanism was elaborated by comparing the device performance with respective electrets of PFO-b-POXD and PFO-b-polystyrene (PS) and PFO homopolymer. We found that PFO-b-POXD can efficiently generate photoexciton under UV illumination to neutralize the trapped hole, and assuage the hole trapping propensity of PFO segment, simultaneously. By optimizing the POXD content in the block copolymer, a decent memory ratio (I_ON/I_OFF) of ~10⁵ was achieved after 10⁴ s, indicating its superior long-term stability and data discernibility. This research shows the judicious strategy to design polymer electret for photonic memory, and it opens up the possibility of developing photonic memory, human perception and futuristic communication systems using simple, convenient and reliable optoelectronic technique.