Two Dawson-templated three-dimensional metal-organic frameworks based on oxalate-bridged binuclear cobalt(II)/Nickel(II) SBUs and Bpy linkers

The Dawson anion P 2W 18O 62 (6-) has been used as a noncoordinating polyoxoanion template for the construction of two metal-organic frameworks, namely, [M 2(bpy) 3(H 2O) 2(ox)][P 2W 18O 62]2(H 2-bpy). nH 2O (M = Co(II), n = 3 ( 1); M = Ni(II), n = 2 ( 2)) (bpy = 4,4'-bipyridine; ox = C 2O 4 (2-)). Single-crystal X-ray analysis reveals that both of the structures exhibit 3D host frameworks constructed from the oxalate-bridged binuclear superoctahedron secondary building units (SBUs) and bpy linkers and the voids of which are occupied by Dawson anions, guest bpy, and water molecules. Magnetic studies reveal that there are antiferromagnetic exchange interactions among the transition-metal centers in compounds 1 and 2. Furthermore, a compound 1-modified carbon paste electrode ( 1-CPE) displays good electrocatalytic activity toward the reduction of nitrite.     

Toroid Formation through a Supramolecular “Cyclization Reaction” of Rodlike Micelles

Constructing polymeric toroids with a uniform, tunable size is challenging. Reported herein is the formation of uniform toroids from poly(γ-benzyl-l -glutamate)-graft-poly(ethylene glycol) (PBLG-g-PEG) graft copolymers by a two-step self-assembly process. In the first step, uniform rodlike micelles are prepared by dialyzing the polymer dissolved in tetrahydrofuran (THF)/N,N′-dimethylformamide (DMF) against water. With the addition of THF in the second step, the rodlike micelles curve and then close end-to-end to form uniform toroids, which resemble a cyclization reaction.     

Structural, magnetic, and magnetoresistive properties of electrodeposited Ni5Zn21 alloy nanowires

Ni5Zn21 alloy nanowires were fabricated through template-assisted electrochemical deposition method. The morphology and microstructures of as-deposited nanowires were determined by field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), electron diffraction (ED), and electron probe microanalysis (EPMA). The accurate composition was measured via induced coupling plasma atomic emission spectroscopy. SEM results show that Ni5Zn21 nanowires are deposited in most of the nanopores of the template, and they are continuous and dense throughout the whole length. The XRD result demonstrates that the nanowires are mainly composed of a cubic gamma phase Ni5Zn21 alloy, but there also exists a trace of Zn-rich eta phase. HRTEM and ED reveal that the alloy nanowires are polycrystalline with the crystallite size of several tens of nanometers. EPMA of a single nanowire illustrates that there exist Ni-rich microzones in as-deposited nanowires. Subsequent magnetic measurements of the array also confirmed the existence of them. In addition, it can be further inferred that the shape of Ni-rich microzones is probably barlike or disklike, from the anisotropy of zero field cooling/field cooling (ZFC/FC) curves as well as the vortex magnetization behavior of the Ni5Zn21 nanowire array. The low-temperature magnetoresistance of the Ni5Zn21 nanowire array was also measured. Giant magnetoresistance instead of anisotropic magnetoresistance is suggested to be responsible for contributing to the magnetoresistance.     

带三次项的非线性四阶Schrdinger方程的一个局部能量守恒格式

本文构造了带三次项的非线性四阶Schodinger方程的一个局部能量守恒格式.证明了该格式是线性稳定的,且能保持离散的整体能量守恒律及离散的电荷守恒律.最后通过数值算例验证了理论结果的正确性.     

Adaptive temporal compressive sensing for video with motion estimation

Optical Review - In this paper, we present an adaptive reconstruction method for temporal compressive imaging with pixel-wise exposure. The motion of objects is first estimated from interpolated...     

杯[4]芳烃衍生物对Pb2＋的液膜传输动力学

以3类含不同基团的杯[4]芳烃衍生物作为离子载体在H2O-CHCl3-H2O液膜传输体系下分别对Pb2＋进行液膜传输实验. 简要讨论了以杯[4]芳烃衍生物作为离子载体对Pb2＋液膜传输的动力学机理. 重点研究了不同载体种类, 载体浓度, 搅拌速度, 传输时间等因素对Pb2＋传输的影响. 实验结果表明: 以含Br原子的杯[4]芳烃衍生物和含S原子的杯[4]芳烃衍生物作为离子载体对Pb2＋有明显的传输效果. 可以用本文的动力学模型来描述整个传输体系的动力学特性.     

基于纳米金辅助信号生成顺序堆积的毛细管电泳免疫分析研究

短裸甲藻毒素（BTX）是具有极强毒性的生物毒素,能够通过食物链传递引起人类中毒.由于该毒素没有光学和电化学信号,检测十分困难.本工作利用纳米金作为载体,将辣根过氧化物酶（HRP）和毒素抗体同时固定到纳米金表面,通过HRP催化H₂O₂氧化邻氨基酚（OAP）产生的电化学信号检测样品中的毒素,增大纳米金表面HRP和抗体的物质的量比使电化学信号得到极大增强.免疫反应样品电动进样引入分离毛细管中,在毛细管入口端进行顺序堆积在线富集,使检测灵敏度进一步提高.该方法通过纳米金辅助信号生成和顺序堆积在线富集技术实现了对扇贝样品中BTX-B的快速灵敏检测,线性范围为0.1~120 ng/mL,检出限为26 ng/L,检出限比常规酶联免疫分析（ELISA）法低365倍.     

Global regularity for 3D generalized Hall magneto-hydrodynamics equations

For the 3D incompressible Hall magneto-hydrodynamics equations, global regularity of the weak solutions is not established so far. The major difficulty is that the dissipation given by the Laplacian operator is insufficient to control the nonlinearities. Wan obtained the global regularities of the 3D generalized Hall-MHD equations with critical and subcritical hyperdissipation in ({\em Global regularity for generalized Hall-magnetohydrodynamics systems}, Electron. J. Differential Equations, 2015, 2015(179), 1--18). We improve this slightly by making logarithmic reductions in the dissipation and still obtain the global regularity.     

不完全博弈学习过程的虚拟行动规则

本文把博弈学习虚拟行动规则的学习时间一般化,研究不完全学习过程中参与人策略选择的收敛性及效用一致性问题. 分析结果表明：当学习时间不完全时,在学习一致到达的条件下,虚拟行动规则对严格纳什均衡是吸收的; 在学习时间充分及时与虚拟行动非频繁转换的条件下,各参与人的虚拟行动具有效用一致性.     

Preparation and characterization of planar heterojunction perovskite solar cells based on c-TiO2/CH3NH3PbI3/HTM/Ag structure

Journal of Sol-Gel Science and Technology - In this paper, A modified one-step method was used to prepare the CH3NH3PbI3 (MAPbI3) perovskite film, and the planar heterojunction perovskite solar...