Syntheses,structure and photoluminescent properties of lanthanide oxalatosulfocarboxylate coordination polymers

Hydrothermal reactions of oxalic acid(H2ox) and 2-sulfobenzoic acid(H2L) with lanthanide oxide or hydroxide yielded five lanthanide oxalatosulfocarboxylates.They have a general formula [Ln2L2(ox)(H2O)6]n[Ln = La(1),Nd(2),Eu(3),Gd(4),Tb(5)].Their structures were characterized by single crystal X-ray diffraction,powder X-ray diffraction(PXRD),infrared(IR) spectroscopy,elemental analysis(EA),and thermogravimetric analysis(TGA).1-5 are isostructural coordination polymers and feature one-dimensional(1D) chains,which are extended into 3D supramolecular frameworks through inter-chain hydrogen bonds between coordinated H2O donors and oxygen acceptors from carboxylate,sulfonate and oxalate groups.In addition,the solid-state photoluminescence properties of the Nd(2),Eu(3) and Tb(5) derivatives have been measured at room temperature.The Eu and Tb-containing coordination polymers(CPs) exhibit intense red and green luminescence emissions,respectively,with lifetimes in the order of millisecond.     

弹性碰撞的图示分析法

通过引入牵连动量和相对动量等物理量,用图示分析法研究了弹性碰撞.研究结果表明,该方法可以形象而直观地描述弹性碰撞的过程和结果,对弹性碰撞的理论研究和实际应用都有重要的意义.     

Preparation and performance of dye-sensitized solar cells based on ZnO-modified TiO<Subscript>2</Subscript> electrodes

The ZnO-modified TiO₂ electrode was prepared by adding Zn(CH₃COO)₂·2H₂O to the TiO₂ colloid during the sol-gel production process, and was used in dye-sensitized solar cells (DSCs). The open circuit voltage (V _OC) and fill factor (ff) of the cells were improved significantly. The performances of the ZnO-modified TiO₂ electrode such as dark current, transient photocurrent, impedance, absorption spectra, and flat band potential (V _fb) were investigated. It is found that the interface charge recombination impedance increases and V _fb shifts about 200 mV toward the cathodic potential. The effect mechanism of ZnO modification on the performance of DSCs may be that ZnO occupies the surface states of the TiO₂ film.     

中华主流文化与文化软实力的提升

要使我国从文化大国成为文化强国，从经济大国成为经济强国，必须着力构建中华主流文化，提升文化软实力。其途径一是要正确认识中华主流文化在软实力建设中的核心地位，二是要发挥好文化软实力的积极作用。     

二醋酸碘苯促进的水相中酮和酚的直接反应

报道了二醋酸碘苯促进的水相中酮和酚的直接反应,在温和的条件下以中等收率合成了一系列的α-芳氧基酮.     

大跨度预应力框架梁应力测试技术研究

应力监测是预应力结构施工监控中的重要部分,结合工程实例介绍了基于混凝土应变测试预应力测试技术,对弥补预应力结构设计中误差,保证施工质量具有重要意义.     

生存的荒诞——戈尔丁《蝇王》的存在主义解读

英国诺贝尔文学奖获得者威廉·戈尔丁的代表作《蝇王》从存在主义视角对人类生存的荒诞进行了思考,本文试从《蝇王》对人类生存环境的荒诞和人与人存在关系的荒谬来分析它的存在主义特质。     

钢架构拆除技术方案探讨

通过对长岭220 kV变电站的母线改造安装工程的调研,同时通过对AIS与GIS变电站所用设备的分析对比,阐述了改建工程中旧架构与设备拆除的重点和难点。     

系数比例自适应算法的研究

系数比例自适应算法是利用系统的稀疏特性而发展起来的一种新的算法。这类算法为每一个滤波器系数引入一个成比例步长参数,使得成比例步长参数与滤波器系数的估计值成正比,保证了大系数获得大步长,缩短了算法的收敛时间。该文首先介绍了系数比例自适应算法的研究背景及研究现状,然后详细描述了典型的系数比例归一化最小均方(PNLMS)算法,最后重点介绍几种改进的PNLMS算法。     

材料成形技术基础双语教学的教改实践

针对地方本科院校的材料成形技术基础双语教学的现状,本文总结了笔者承担双语教学任务中进行教学改革的一些经验和体会,并着重对双语教材、网络平台和教学措施进行了分析和讨论。