THE CATALYTIC EFFECTS OF OXYGEN AND AMINES IN THE REDOX-INITIATED DIMERIZATION OF N-VINYLCARBAZOLE*

The redox reaction between N-vinylcarbazole (NVC) and various oxidants including Ce(Ⅳ), Fe(Ⅲ)and benzoylperoxide in methanol proceeds via the initial formation of the NVC N-cation radical which in turn leads to the formation of the NVC cyclic dimer, trans-1,2-dicarbazylcyclobutane. Molecular oxygen and a few arylamines are able to accelerate the rate of the formation and increase the yield of the dimer. The mechanism of this process and the functions of oxygen and arylamines are presented as follows: The participation of molecular oxygen is to facilitate the dissociation of the resulting reduced metal ion and the NVC N-cation radical ion pair or charge transfer complex, thereby releasing the free NVC N-cation radical and increase the rate of the formation and yield of the dimer. The arylamine in this reaction between NVC and oxidants can be viewed as electron transfer agent between NVC and the oxidant. Because the amines are present in small amount relative to the oxidants and can be regenerated in pr     

数字MMDS系统设计

介绍MMDS数字电视系统的整体架构与设计原理,MMDS的发射与接收,MMDS收发天线的技术特点,以及MMDS的现状与发展趋势。     

Function S-rough Sets and Their Law Characteristic

Function S-rough sets(Function Singular rough sets) are defined by R-function equivalence class which has dynamic characteristic, and a function is s law, function S-rough sets have law characteristic. Function S-rough sets has these forms: function one direction S-rough sets, function two direction S-rough sets and dual of function one direction S-rough sets. This paper presents the law characteristic of function one direction S-rough sets and puts forward the theorems of law-chain-attribute and law-belt. Function S-rough sets is s new research direction of the rough sets theory.     

Si-Si直接键合的研究及其应用

硅片直接键合技术是一种简单易行的硅片熔合技术,由于该技术不受材料的结构、晶向和点阵参数的影响,因而得到了广泛的应用。介绍了硅片直接键合的方法和键合模型,并简单介绍了硅片直接键合技术的应用。     

软件的MTBF及其验证试验

目前国内计算机软件绝大部分没有ＭＴＢＦ指标要求，个别有指标要求的也无验证考核办法，故实际上其软件的可靠性是没有保证的。从硬件可靠性发展的经验看，软件必需有ＭＴＢＦ要求，必需切实通过验证试验后才能交付使用方。本文提出一种软件ＭＴＢＦ指标分配方法及通过软件测试平台的验证试验考核方法。对不太大的软件而言，软件测试平台可以用３８６、４８６来实现，在手段上一般不成问题。验证试验成功的前提是完整的软件任务书，     

CO_2及YAG激光外切,内照射治疗痔疮六十例的临床应用

痔疮的疗法很多,各家意见不一。本组采用CO_2激光治疗痔疮效达90%;无感染和其它合并症。对外痔采用CO_2切割治疗;内痔用YAG照射治疗。激光操作简便,它可一次完成切割、止血、缝合三个步骤,绝大多数术后基本无痛或轻微痛,服去痛片