Isolation, absolute configuration, and chiral crystallization of optically active seleninic acid

An optically pure seleninic acid was isolated as stable crystals for the first time by chiral crystallization. The relationship between the absolute configurations and the circular dichroism spectra of the enantiomers could be determined by X-ray crystallographic analysis.     

e~（－1）＜（压缩因子Z）＜e的高压混合气体的状态方程

从正则系综的基本公式出发，绕开对位形积分的具体计算，结合热力学能态方程，求出了ｅ￣（－１）＜（压缩因子Ｚ）＜ｅ的定容高压实际混合气体在任意（Ｔ＿ｏ，ｐ＿ｏ）附近压力与温度的一般解析式，并与实验值进行了对照。应用本文导出的公式在工程热物理方面可减少实验测试的次数，在石化工业中可用来计算环境温度的变化对高压储气罐内压力的影响。     

Convenient syntheses of (3S,5S)-carbapenam-3-carboxylates and their biosynthetic relevance

Starting from readily available glutamate derivatives, facile stereoselective syntheses of (3S,5S)-carbapenam-3-carboxylates have been developed. Their significance in confirming the absolute configuration of the natural material is discussed.     

高l态对镁原子自电离光谱的影响

采用多通道量子数亏损理论与Ｋ反应矩阵相结合的理论处理方法，研究了高ｌ组态３ｐｍｌ、（ｌ＝４）对于镁原子３ｐｎｄ（Ｊ＝３）自电离光谱的影响．在处理中引入３ｐｎｇ（Ｊ＝３）组态的影响后能够完整地描述３ｐｐｎｄ（Ｊ＝３）自电离光谱．通过对自电离光谱的细微结构的研究，讨论了有关的实验现象的物理机制．理论结果与实验一致．     

NMR study on 9‐S and 9‐R oxirane derivatives of ascomycin

Structure elucidation of 9‐S and 9‐R oxirane derivatives of ascomycin, a 23‐membered immunomodulating macrolactam, was performed using NMR spectroscopy. The total ¹H and ¹³C signal assignments required the gradient‐selected versions of COSY (gs‐COSY), heteronuclear multiple quantum‐correlation spectroscopy (gs‐HSQC), heteronuclear multiple‐bond correlation spectroscopy (gs‐HMBC), and nuclear Overhauser methods. The data sets then were used to examine the dependence of ketone–hemiketal and cis–trans amide equilibria on the substitution pattern and the absolute configuration of the chiral oxirane. Copyright © 2002 John Wiley & Sons, Ltd.     

组合数学方法推引原子谱项（Ⅲ）非等效组态的谱项及其微机处理

讨论了推引非等效组态原子谱项的组合数学方法和矢量加和法，并编制了ＢＡＳＩＣ语言程序，在微机上快速推求非等效组态的谱项。     

1.06μm连续与脉冲激光对GaAs材料的联合破坏效应

通过1.06μm连续激光和脉冲激光联合破坏GaAs材料的实验研究, 给出了GaAs材料在三种不同的连续激光功率密度辐照下, 所需脉冲激光的破坏阈值, 结果表明, 联合破坏时所需脉冲激光的破坏阈值小于单独使用脉冲激光的破坏阈值。根据轴对称二维热模型, 计算了三种情况下连续激光辐照时GaAs材料的表面温度分布曲线及表面辐照中心处温升随辐照时间的关系, 并估算了其后作用的脉冲激光对材料的温升, 对实验及计算结果进行了分析, 并着重比较了联合破坏方式和单独破坏方式的优缺点。