On the limiting factor of impregnation methods for developing Cu/CeO<Subscript>2</Subscript> anodes for solid oxide fuel cells

The efficiency of impregnation methods for making Cu-based solid oxide fuel cells (SOFCs) is qualitatively characterized for the first time through a conformal coating model. It is found that the low-efficiency results from the uneven distribution of Cu instead of the small loading. Most of the Cu deposits form isolated islands, e.g., in a 20.4 vol.% Cu-loaded anode, 81% Cu is isolated from each other. In order to address the limited impregnation efficiency, two different procedures are adopted to fabricate the practical Cu/CeO₂ anodes, namely, simultaneous and sequential impregnation procedures. It is found that CeO₂ works as a solid dispersant, improving the Cu distribution drastically. Compared to the Cu-only anode, more than a threefold improvement of impregnation efficiency is achieved by both methods. The anode made by the sequential impregnation yields the best performance in CH₄ at 700 °C, 170 mW cm^?2, which represents an 18% enhancement over that of the simultaneous impregnation, or 340% over the Cu-only anode. These findings demonstrate that it is of importance to optimize the Cu impregnation to yield a highly active anode, and the sequential impregnation method is a promising procedure to break the efficiency-limiting factor and produce a high-performance anode with minimized fabrication effort.     

柱前衍生反相高效液相色谱法测定七种中药补养药中氨基酸

首次分离并测定了七神中药补养药中氨基酸，为其补益作用提供了科学依据．并建立了中药补养药的FMOC-氨基酸色谱测定方法。以FMOC-Cl(9-芴基甲氧基羰酰氯)为柱前衍生试剂，用反相高教液相色谱法测定氨基酸是国内报道甚少的新方法。该法衍生操作简单，衍生反应迅速．衍生物稳定，方法的灵敏度高、分辨率好，整个分析过程简捷，耗用时间短，优于用氨基酸分析仪分析氨基酸。常用的OPA(邻苯二甲醛)柱前衍生法不能直接测定二级胺类的氨基酸，该法则可直接测定一级及二级胺类的氨基酸．同时，该法受样品基质干扰少，从而为衍生物样品的氨基酸分析开辟了广阔前景。本文用该法测定了七种氨基酸，获得了较满意结果，并认为该法对中草药及重要天然植物资源的研究是一个简捷，准确且极其实用的新方法。     

苯基及取代苯基四唑异构反应的量子化学研究

与四唑相同，对位取代苯基四唑有两种异构体（见图1）.几十年来，实验工作者对这类化合物在医药和农业等方面的应用研究表现出浓厚兴趣［‘-‘1.最近，我们用从头计算和PM3等方法研究了四唑两种异构体间异构化反应的机理问.为了探明这类反应的取代基效应，本文报导用PM3方法[6]     

A convenient cyclopropanation process of oxindoles via bromoethylsulfonium salt

A practical convenient conversion of oxindoles into the corresponding spirocyclopropyl oxindoles is achieved efficiently using bromoethylsulfonium salt, which is easily prepared on a large scale and is stable crystalline. This reaction of bromoethylsulfonium salt with different substituted unprotected oxindoles proceeded under mild condition and provided moderate yields.     

浙江槭属植物新记录

作为浙江槭属植物区系的补充，报道了浙闽槭Acer johnedwardianum F.P.Metcalf、乳源槭A. chunii Fang和九江三角枫A. buergerianum Miq. var. jiujiangense Z.X. Yu 3个植物分布新记录；补充描述了浙闽槭、乳源槭花的形态特征；恢复了浙闽槭的种级地位。     

煤在热载体流化床中的热解模型

煤粒在热载体流化床中的热解规律对于设计煤气、热、电三联产的关键装置－热载体流化床干馏炉是十分重要的。本文建立了煤粒在热载体流化床中的传热和热解反应的微分方程，并对其进行了数值求解，得到了煤粒度、热载体流化床操作速度、热载体流化床床层温度、热载体颗粒粒径等对煤气产率的影响规律，为热载体流化床干馏炉的设计提供了计算方法和理论依据。