Random fixed points of set-valued operators

Some random fixed point theorems for set-valued operators are obtained. The measurability of certain marginal maps is also studied. The underlying measurable space is not assumed to be a Suslin family.

     

Synthesis and Crystal Structure of a Three-dimensional Cd(Ⅱ) Coordination Polymer [Cd(μ1,3-SCN)(μ3-pco)]n (pco = Pyrazine-2-carboxylate 4-oxide Anion)

The three-dimensional complex [Cd(μ1,3-SCN)(μ3-pco)]n has been synthesized with μ1,3-SCN- and pco as mixed bridged ligands. The crystal belongs to monoclinic, space group P21/n with a = 10.3777(16), b = 6.2592(9), c = 13.150(2) (A), β= 97.317(2)°, V=847.2(2) (A)3, Z= 4,C6H3CdN3O3S, Mr = 309.575, Dc = 2.427 g/cm3, F(000) = 592 and μ = 2.804 mm-1. The structure was refined to R = 0.0255 and wR = 0.0550 for 1712 observed reflections (I＞2σ(I)). In the crystal the Cd(Ⅱ) ions are coordinated by μ1,3-SCN- and μ3-pco bridge ligands to form a three-dimensional structure.     

基于GaSb/CdS薄膜热光伏电池的器件设计

基于GaSb薄膜热光伏器件是降低热光伏系统成本的有效途径之一, 本文主要针对GaSb/CdS薄膜热光伏器件结构进行理论分析. 采用AFORS-HET软件进行模拟仿真, 分析GaSb和CdS两种材料各自的缺陷态密度、界面态对电池性能的影响. 根据软件模拟可以得知, 吸收层GaSb的缺陷态密度以及GaSb与CdS之间的界面态密度是影响电池性能的重要因素. 当GaSb缺陷态增加时, 主要影响电池的填充因子, 电池效率明显下降. 而作为窗口层的CdS缺陷态密度对电池性能影响不明显, 当CdS缺陷态密度上升4个数量级时, 电池效率仅下降0.11%.     

On Statistical Properties of Hyperbolic Systems with Singularities

We study hyperbolic systems with singularities and prove the coupling lemma and exponential decay of correlations under weaker assumptions than previously adopted in similar studies. Our new approach allows us to study the mixing rates of the reduced map for certain billiard models that could not be handled by the traditional techniques. These models include modified Bunimovich stadia, which are bounded by minor arcs, and flower-type regions that are bounded by major arcs.     

Novel Ag2S nanoparticles on reduced graphene oxide sheets as a super-efficient catalyst for the reduction of 4-nitrophenol

Here,Ag_2S nanoparticles on reduced graphene oxide(Ag_2S NPs/RGO) nanocomposites with relatively good distribution are synthesized for the first time by conversing Ag NPs/RGO to Ag_2S NPs/RGO via a facile hydrothermal sulfurization method.As an noval catalyst for the reduction of 4-nitrophenol(4-NP),it only takes 5 min for Ag_2S NPs/RGO to reduce 98% of 4-NP,and the rate constant of the composites is almost 13 times higher than that of Ag NPs/RGO composites.The high catalytic activity of Ag_2S NPs/RGO can be attributed to the following three reasons:(1) Like metal complex catalysts,the Ag_2S NPs is also rich with metal center Ag(δ~+),with pendant base S(δ) close to it,and thus the Ag and basic S function as the electron-acceptor and proton-acceptor centers,respectively,which facilitates the catalyst reaction;(2)RGO features the high adsorption ability toward 4-NP which provides a high concentration of 4-NP near the Ag_2S NPs;and(3) electron transfer from RGO to Ag_2S NPs,facilitating the uptake of electrons by 4-NP molecules.     

Properties and Iterative Methods for the Lasso and Its Variants

The lasso of Tibshirani （1996） is a least-squares problem regularized by the l1 norm. Due to the sparseness promoting property of the l1 norm, the lasso has been received much attention in recent years. In this paper some basic properties of the lasso and two variants of it are exploited. Moreover, the proximal method and its variants such as the relaxed proximal algorithm and a dual method for solving the lasso by iterative algorithms are presented.     

Ni_2P/TiO_2-Al_2O_3催化剂的制备及其加氢脱硫、脱氮性能

采用溶胶-凝胶法制备了TiO2-Al2O3复合载体,采用浸渍法制备了Ni2P/TiO2-Al2O3催化剂,并用X射线衍射(XRD)、N2吸附比表面积(BET)测定、热重-差热分析(TG-DTA)、X射线光电子能谱(XPS)等技术对催化剂的结构和性质进行了表征.催化剂加氢脱硫(HDS)和脱氮(HDN)活性评价在实验室固定床连续反应装置上,以噻吩和吡啶为模型反应物进行.考察了不同载体、Ni2P负载量、标称Ni/P摩尔比、催化剂焙烧温度对Ni2P/TiO2-Al2O3催化剂上同时进行的噻吩加氢脱硫和吡啶加氢脱氮性能的影响.结果表明,TiO2含量为80%(w)的TiO2-Al2O3复合氧化物为载体,Ni2P负载量为30.0%(w),标称Ni/P摩尔比为1/2,催化剂焙烧温度为500℃时,Ni2P/TiO2-Al2O3催化剂加氢脱硫脱氮活性最高.在360℃,3.0MPa,氢油比800(V/V),液时体积空速1.5h-1的条件下,噻吩HDS和吡啶HDN转化率分别为61.32%和64.43%.