2-(2-喹啉偶氮)-5-二甲氨基苯胺光度法测定铜

在pH=4.0的磷酸盐缓冲介质中,CTMAB存在下,2-(2-喹啉偶氮)-5-二甲氨基苯胺(QADMAA)与铜反应生成2:1稳定络合物,络合物λmax=580nm,ε=1.14×105L·mol-1·cm-1.铜含量在0.01-0.6μg/mL内符合比耳定律,方法用于环境样品中铜的测定,结果令人满意.     

Three-Photon Absorption and Upconversion Fluorescence Properties of Series 1,3,4-Oxadiazole Derivatives

A newly synthesized 1,3,4-oxadiazole derivatives have been studied using a femtosecond Ti：sapphire laser system. The series molecules present strong three-photon absorption and frequency upeonversion fluorescence at wavelengths from 1205 nm to 1575 nm. Furthermore, there is no proportional relationship between three-photon absorption cross sections and the chemical structure transformation from monomer, dimer to trimer. Effective charge-transfer distance by π-conjugation bonds may be the contributing factor. In the experimental design, the far-field intensity distribution of femtosecond laser beam has been taken into account. We give the optimized analytical solution of nonlinear transmission in a three-photon absorption （3PA ） process when the incident beam has a Gaussian transverse spatial profile.     

高温高压下β相硼的电导率测量

 硼在高压下具有复杂的结构和多样的物理性质,对其结构和性质的深入研究具有很重要的意义,一直引起理论和实验研究领域的关注。高压下进行电学性质测量是获得物质物理性质的有效手段,利用集成在金刚石对顶砧上的微电路,在高压下和两个不同温度范围内对β相硼进行了电导率测量,分析了导电机制随压力的变化规律。在0～28.1 GPa范围内,β相硼的电导率随着压力的增大是逐渐增大的,卸压后样品的电导率不能回到最初的状态,是一个不可逆的变化过程;由室温到423 K的范围内,β硼的电导率随着温度的不断增加有明显的上升趋势,并且随着压力的升高,电导率变化逐渐加快。此外,对样品在14.5 GPa和18.6 GPa压力下,用溅射到金刚石对顶砧上的氧化铝薄膜做绝热层,对样品进行了激光加热实验,最高温度达到2 224 K,电导率随着温度的上升而增大,结果显示,β相硼的电学特征仍然属于半导体的特征范围内。     

规范理论中反常的拓扑意义与规范群的?ech-de Rham上同调

本文分析了规范群上同调的拓扑障碍。指出规范群上同调的上边缘算子相当于?ech的差映射算子。采用逐级分区的方法克服以往常用的d^-1算子的含混性,而且将各阶上闭链与指数Z相联系,澄清了规范群上闭链的整体拓扑意义。 关键词：     

Network dynamics and its relationships to topology and coupling structure in excitable complex networks

All dynamic complex networks have two important aspects, pattern dynamics and network topology. Discovering different types of pattern dynamics and exploring how these dynamics depend or/network topologies are tasks of both great theoretical importance and broad practical significance. In this paper we study the oscillatory behaviors of excitable complex networks （ECNs） and find some interesting dynamic behaviors of ECNs in oscillatory probability, the multiplicity of oscillatory attractors, period distribution, and different types of oscillatory patterns （e.g., periodic, quasiperiodic, and chaotic）. In these aspects, we further explore strikingly sharp differences among network dynamics induced by different topologies （random or scale-free topologies） and different interaction structures （symmetric or asymmetric couplings）. The mechanisms behind these differences are explained physically.     

用激光散斑照相研究高温差自然对流换热

一、测量原理与方法 使用散斑照相测量加热竖板自然对流温度场的实验装置如图1所示。来自He-Ne激光器LS的光束经过聚焦透镜L1,针孔滤波器Al和准直透镜L2后,以一束准直平行光束通过测试段TS。前置放大透镜L_8将测试段成像在毛玻璃GG上。当激光束照射毛玻璃时,被毛玻璃粗糙表面所散射的光束会在空间形成     

富钙镁离子溶液以碳酸盐沉淀固定CO2的试验研究

提出了利用富钙镁离子溶液（海水淡化产生的浓海水、地下卤水、高硬度工业废水等）以碳酸盐沉淀形式实现CO₂固定的思路,以2倍浓度的海水为例进行分析,表明富钙镁离子溶液具有可观的固碳潜力。考察了氨水-氯化铵溶液、氨水-碳酸氢铵溶液和有机胺（MEA、MDEA）作为添加剂提高溶液pH值的方式对碳酸盐沉淀形成能力的影响。结果表明这三种添加剂均可在一定程度上提高溶液pH值,促进富钙镁离子溶液中难溶碳酸盐沉淀形成。     

对磺酸基苯基亚甲基若丹宁固相萃取光度法测定银

研究了对磺酸基苯基亚甲基若丹宁(SBDR)与银的显色反应,在pH为2.6的柠檬酸-氢氧化钠缓冲介质中,吐温-80存在下, SBDR与银反应生成2∶1稳定络合物,该络合物可用Waters Porapak Sep-Park固相萃取小柱富集,用乙醇(含5％乙酸)溶液洗脱后用光度法测定,在乙醇介质中λ_max＝520 nm,摩尔吸光吸数ε＝7.53×104 L·mol-1·cm-1。银含量在0～1.2 μg·(25 mL)-1内符合比尔定律,方法用于环境水样中银含量的测定,结果令人满意。     

High pressure electrical transport behavior in SrF_2 nanoplates

The charge transport behavior of strontium fluoride nanocrystals has been investigated by in situ impedance measurement up to 35 GPa.It was found that the parameters changed discontinuously at each phase transition.The charge carriers in SrF_2 nanocrystals include both F~-ions and electrons.In the Fm3 m phase,pressure makes the electronic transport easier,while makes it more difficult in the Pnma phase.The defects at grain boundaries dominate the electronic transport process.Pressure could make the charge-discharge processes in the Fm3 m phase much easier,but make it more difficult in the Pnma phase.     

粘度和电阻率系数依赖于密度的三维不可压缩磁流体力学方程组局部强解的适定性

研究粘性和电阻率系数依赖于密度的三维不可压缩磁流体力学方程组,证明该方程组的初边值问题的局部强解存在唯一,并且在一定的相容性条件下,该局部强解连续依赖于初始数据.