用会聚偏振光测定双轴热拉伸有机玻璃板的双折射值的研究

介绍了用会聚偏振光测定双轴热拉伸定向有机玻璃板双折射值的原理和实验方法,并提出了对Kramer计算公式的简化和改进。测定了双折射值与拉伸度、拉伸温度的关系并分析了干涉图。     

拓扑指数法研究显色剂结构与反应性能关系

本文讨论了２９个不对称色酸双偶氮膦酸型显色剂的分子联接性指数，并将其与结构选择性因子相结合，用于偶氮类剂结构与铈显色反应灵敏度的相关性研究，讨论了显色剂结构对显色反应灵敏度的影响。     

含嘧啶环的双冠醚(Ⅳ)

前文已报道由啶环桥联两个苯并冠醚的双冠醚的合成与性质。由于嘧啶环的刚性较大,能把两个冠醚单元固定在有效地协同作用位置,因此以它们作中性载体的离子选择性电极具有较好的选择性。为了进一步研究这类双冠醚的性质,我们合成了四种嘧啶环桥联两个脂肪族冠醚的双冠醚,并经元素分析、IR、′HNMR鉴定。     

Process study of thermal plasma chemical vapor deposition of diamond,part II: Pressure dependence and effect of substrate pretreatment

The effect of pressure during thermal plasma chemical vapor deposition of diamond films has been investigated for a pressure range from 100 to 760 Torr. The maximum growth rate in our experiments occurs at 270 Torr for substrate temperatures around 1000°C. The existence of an optimum pressure for diamond deposition may he related to the balance between generation and recombination of atomic hydrogen and carbon-containing active species in front of the substrate. To estimate the concentrations of atomic hydrogen and methyl radicals under thermal plasma conditions, calculations based on thermodynamic equilibrium have been performed. This approximate evaluation provides useful guidelines because rapid diffusion results in a near frozen chemistry within the boundary layer. The effect of substrate pretreatment on diamond deposition depends on the type of substrate used. Two growth modes have been observed-layer growth and island growth of diamond crystals on various substrates. Screw dislocations have been observed in diamond deposition in thermal plasmas, and defects such as secondary nucleations are more concentrated along (III) directions than along (100) directions.     

Facile synthesis of 9-（N-amino-4-fluoromethyl-3-pyrrolidinyl）-2- fluoro-6-aminopurine from trans-4-hydroxy-L-proline

A novel and simple procedure for synthesis of azanucleoside by Mitsunobu reaction between N-(p-nitrobenzyloxycarbonyl)- trans-4-hydroxy-D-proline methyl ester obtained from trans-4-hydroxy-L-proline after six-step reaction and 2-fluoro-6-azidopurine is described,and azanucleoside is fluorinated by new fluridizer 2,2-difluoro-1,3-dimethylimidazolidine (DFI).All reactions could be carded out under mild condition.     

Selective dimerization of α-methylstyrene catalyzed by a solid acid

A novel solid acid prepared from concentrated sulfuric, boric and phosphoric acid is a highly selective catalyst for the dimerization of α-methylstyrene at room temperature to generate 4-methyl-2,4-diphenyl-1-pentene.     

3，19－二羟基－1－硫杂－5，8，11，14，17－五氧杂环二十烷的醚化与缩聚反应

３，１９－二羟基－１－硫杂－５，８，１１，１４，１７－五氧杂环二十烷（简称二羟基硫杂２０－冠－６）在一缩二乙二醇二甲醚和氢化钠存在下可与卤代烷顺利地进行醚化反应，得到双己氧基、双十二烷氧基、双十六烷氧基、双节氧基和双烯丙氧基硫杂２０－冠－６，同时也得到了单己氧基、单十二烷氧基、单十六烷氧基和单辛氧基单羟基疏杂２０－冠－６副产物。二羟基硫杂冠醚可顺利地与丁二酰氯缩聚，得到主链含硫杂冠醚基团的聚酯     

Molar conductivity calculation of Li-ion battery electrolyte based on mode coupling theory

A method is proposed to calculate molar conductivity based on mode coupling theory in which the ion transference number is introduced into the theory. The molar conductivities of LiPF6, LiClO4, LiBF4, LiAsF6 in PC (propylene carbonate) are calculated based on this method. The results fit well to the literature data. This presents a potential way to calculate the conductivities of Li-ion battery electrolytes.