THERMODYNAMICS OF AMINO-ACID DISSOCIATION IN MIXED-SOLVENTS .3. GLYCINE IN AQUEOUS GLUCOSE SOLUTIONS FROM 5-DEGREES-C TO 45-DEGREES-C

The first thermodynamic dissociation constants of glycine in 5, 15 mass % glucose + water mixed solvents at five temperatures from 5 to 45-degrees-C have been determined from precise emf measurements of a cell without liquid junction using hydrogen and Ag-AgCl electrodes and a new method of polynomial approximation proposed on the basis of Pitzer's electrolytic solution theory in our previous paper. The results obtained from both methods agree within experimental error. The standard free energy of transfer for HCl from water to aqueous mixed solvent have been calculated and the results are discussed.

青海湖布哈河下游地区植物群落多样性研究

根据野外样方调查资料，对青海湖西部布哈河下游地区8种植物群落进行了研究。结果表明：群落的多样性随丰富度的降低而呈下降趋势，均匀度的变化受物种丰富度的影响不大，群落的物种多样性指数与丰富度指数和均匀度指数均表现出极显著的正相关性（P〈0．01），相关系数分别为0．912和0．684；群落的均匀度与丰富度相关性不显著，说明物种多样性主要为物种丰富度所推动。

强流脉冲离子束辐照45钢表面热效应的模拟

以Fourier瞬态传热方程为基础,确定了强流脉冲离子束(HIPIB)热效应的基本传热方程,对靶材45钢进行不同能量参数的HIPIB辐照热效应的模拟计算.针对离子注入金属内部的情况,在模拟束流加载方式上分别采用体加载和面加载,比较了两种加载计算结果之间的差距.本算法的另一个改进就是在高能量辐照下,用单元死活法对蚀坑部分材料的消失进行模拟.结果表明,用单元死活法模拟单元的失效,更能符合HIPIB辐照金属表面热效应的蚀坑机制;单元死活法对靶材的升温过程没有明显影响,但对冷却阶段,可以显著提高模拟的精度.