碳酸及碳酸酯热消除反应的量子化学研究

用AM1方法研究了碳酸和碳酸酯的热消除反应．发现迁移基团R和基团R’共同制约这类吸热反应的活化能。     

LiCoO2中锂离子固相扩散系数随循环次数的变化

The solid diffusion coefficient of lithium-ion in LiCoO₂ cathode material has been investigated by the capacity intermittent titration technique (CITT) at different voltages and at different charge/discharge cycles. By SEM, XRD and FTIR techniques, the structure of LiCoO₂ was studied before and after charge-discharge cycles, and the relationship between solid diffusion coefficient and crystal structure was further discussed. CITT results show that the value of Li⁺ solid diffusion coefficient of LiCoO₂ is about 10^-12 cm²·s^-1. During the whole charge-discharge cycles, the Li⁺ solid diffusion coefficient decreased within the voltage of 4.0～4.3 V, which is attributed to the change of the structure of LiCoO₂.     

WS2 超细粉体的固相法合成

WS2 超细粉体的固相法合成;WS2;固相反应;过硫系数;高能球磨;粒度     

室温下非极性溶剂中氧鎓盐的定域激发

氧鎓盐类化合物因具有较强的亲电性，在有机合成[1]及电照相体系[2]中存在着广泛的应用前景．由于它们还表现出较强的荧光发射能力［3］，因而在作为激光工作材料［4，5］方面也受到重视．正因如此，这类化合物的光物理和光谱特性引起了许多化学家的兴趣．氧钠盐化合物溶液的荧     

核磁共振法测定高聚物的结构—核磁共振二维谱

介绍了核磁共振(NMR)波谱,尤其是核磁共振二维谱(2D NMR)在最近几年内的进展。内容包括怎样用NMR测定高聚物的序列分布、共聚物结构、聚合物的混溶性、聚合物液晶的取向度、分子量、短链度和长链支化度、凝聚态高聚物的多相结构等。     

Ni-SDC固体氧化物燃料电池阳极的合成和性质

采用柠檬酸-硝酸盐溶胶-凝胶低温自蔓延燃烧法制备氧化镍（NiO）粉末和Ce0.8Sm0.2O1.9（SDC）粉末，并将NiO与SDC按不同质量比和不同制备工艺制备了固体氧化物燃料电池（SOFC）的阳极前身。再用自组装的还原装置将其在820℃经2．5h还原后，采用四端子法测量其电导率值。分析了阳极片电导率与阳极片微结构、Ni的质量百分数、混合研磨时间及烧结温度之间的关系。结果显示，阳极片的电导率强烈依赖于镍含量和制备工艺。     

Synthesis and Structure of Ag_3PSe_4

The title compound Ag3PSe4 was synthesized by the reaction of Ag powder,P2Se5 and Se in a molar ratio of 1:1:1 at 500℃ and structurally characterized by X-ray crystallography.The crystal belongs to orthorhombic,space group Pmn21 with cell parameters:a=7.689(4),b=6.660(3),c=6.379(4)A,V=326.7(3)A^3,Z=2,Dc=6.816g/cm^3,Mr=670.42,F(000)=584,μ=31.302mm^-1,R=0.0606,wR=0.1289 and S=1.012,The 3-D structure can be regarded as constructed from the stacking of puckered Ag-P-Se honeycomb-like sheets along the c direction,in which the Ag,P and Se atoms are bonded to each other to form a chair-like six-membered ring,and the rings then build the sheets by sharing edges.     

Electrical Potential Distribution around a Charged Colloidal Particle: Nonlinear Integral Equation

多电解质溶液中带电胶体粒子的电势分布由球形Ｐｏｉｓｓｏｎ－Ｂｏｌｔｚｍａｎｎ方程（ＰＢＥ）描述．ＰＢＥ是一个非线性的微分方程，且难以求得其解析解．本文采用非线性Ｐ－Ｂ积分方程，计算电势分布的数值解．首先，根据静电场和热力学系统中的物理定理，导出描述电势分布的Ｐ－Ｂ积分方程（ＰＢＩＥ）；其次，用迭代方法求ＰＢＩＥ的数值解．最后，计算了在３－１型电解液中无量纲半径κａ分别为０．１２和０．２２，无量纲表面电势ξ分别为１，２，４，６时球形胶体粒子外部的电势值．为了检验数值解的精度，计算了表面电荷密度，并与Ｌｏｅｂ（１９６１）和Ｏｓｈｉｍａ（１９９５）等人的结果比较，本文结果的相对误差小于１％，优于Ｏｓｈｉｍａ的结果．     

Fiber-in-Tube Solid Phase Extraction (FIT-SPE) for Miniaturized Sample Preparation Process

A typical analytical separation procedure has several important steps: sample preparation, isolation, identification, quantitation, statistical evaluation and final decision. Each step is alwayscritical to obtain correct results to fulfill the analytical purpose. In these various steps sample