在超声辐射作用下的游离基加成     

崔结 《湖州师范学院学报》1997,(6)

在超声辐射下,烯烃与四氯化碳、氯仿、醇等能在常温下发生游离基加成反应,并可得到较满意的产率,超声对游离基加成反应有明显的促进作用。  相似文献   

An appreciation of free radical chemistry 3. Free radicals in diseases and health     

G. Nagendrappa 《Resonance》2005,10(4):65-74

  相似文献   

M-分次环的弱分次根扩张     

王尧 《鞍山师范学院学报》2005,7(4):1-2

证明了如果M分次环S=x∈MSx是其分次子环R=x∈mRx的弱分次根扩张,则有JG(R)=JG(S)∩R.  相似文献   

反原子转移自由基聚合的研究——AIBN/CuCl_2/bpy引发St聚合   总被引：1，自引：0，他引：1  

Xia Ping 《湖州师范学院学报》2001,(3)

在原子活性自由基聚合中 ,St可用引发剂 (AIBN)通过一种新的方法成功聚合 .此反应首先在 6 0℃持续10hr,然后在 10 0℃聚合 .我们在引发体系中 ,使用不同摩尔比的AIBN和CuCl2 对此进行试验 ,实验结果说明此种聚合方法引发效率高 ,易于控制 ,所得产物分子量分布窄 ,一般情况下Mw/Mn =1.36 .  相似文献   

惰性浓盐介质法制备纳米晶的研究--纳米Mg(OH)2的制备     

易求实 《培训与研究》2004,21(5):17-19

通过纳米Mg(OH)2粉体的制备说明，在一种本身不参与反应的惰性浓盐介质中进行沉淀反应，能够获得纳米尺度的产物，检索国内几大科技情报检索系统，未见报道。  相似文献   

炔烃部分氢化机理的探讨     

向宁虎 《青海师专学报》2001,21(6):70-71

讨论了炔烃采用选择催化加氢得到不同立体异构体顺式烯烃和反式烯烃的机理。  相似文献   

字典部首法的起源及其发展     

刘海霞 《辽宁师范大学学报(社会科学版)》2004,27(2):105-107

这里首先讨论了汉字字典部首法的起源，认为它是由东汉许慎所创造的，受到了东汉以前的杂字书的启示。还论述了许慎以后字典部首法的发展及其趋势。  相似文献   

反应中间体的实验     

文瑞明  罗新湘  俞善信 《湖南城市学院学报》2001,18(6):45-46

介绍了三苯甲基自由基、三苯甲基正离子和三苯甲基负离子的实验方法.  相似文献   

The Role of the School District in Student Discipline: Building Consensus in Cincinnati     

Lionel H. Brown  Kelvin S. Beckett 《The Urban Review》2006,38(3):235-256

The problem of student discipline disproportionately affects urban schools with large numbers of low income and ethnic minority students. Research over the past 35 years however has consistently shown that discipline policies that are understood and accepted by teachers, students, and parents and consistently enforced by school officials, correlate with lower levels of student disruption. The important role that urban school districts can play in building consensus in support of student discipline policies has not been well documented. But increased levels of student mobility in large urban areas, and increased diversity among the families served by urban districts, highlight the need for district-wide codes of behavior that provide schools with a range of discipline programs that serve the needs of their particular communities. The purpose of this article is to demonstrate how the process of developing and implementing a district-wide code of student behavior in Cincinnati played an important role in reducing disruptive behaviors leading to student suspension and expulsion. By involving all stakeholders in the development of its policies, and by responding to the concerns of all stakeholders in the range of programs it offered, the Cincinnati Public Schools was able to build consensus across socioeconomic and ethnic lines and make its code of behavior effective. On the basis of the evidence presented, it is argued that urban school districts can play a more active role in the area of student discipline. By developing and implementing district-wide codes of behavior that are understood and accepted by teachers, students, and parents, and consistently enforced by school officials, urban districts can lay the foundation on which schools can build healthy learning communities. Dr. Lionel H. Brown holds Bachelors, Masters, and Doctoral degrees from the University of Cincinnati. Dr. Brown is retired from the Cincinnati Public Schools (CPS) where he served as a teacher, vice-principal, principal, and Deputy Superintendent. His responsibilities in the role of CPS Deputy Superintendent included the Department of Curriculum and Instruction, the Office of Student Discipline, and the Office of Student Affairs. Dr. Brown is currently an Assistant Professor in the Division of Educational Studies, College of Education, Criminal Justice, and Human Services, University of Cincinnati, Cincinnati, Ohio. His research and teaching interests include urban education, alternative education, and programs for Black males.Dr. Kelvin S. Beckett holds Bachelors and Masters degrees from the University of British Columbia, Canada and a Doctoral degree from the University of London, United Kingdom. He is an Adjunct Lecturer in the Division of Educational Studies, College of Education, Criminal Justice, and Human Services, University of Cincinnati, Cincinnati, Ohio. His teaching and research interests include urban education and alternative education.  相似文献   

拟环模的完全素根     

王树桂 《怀化学院学报》1992,(6)

本文引入了拟环模的完全素模,完全素根,完全左素理想,完全素环等概念,给出了完全素根的有关性质。  相似文献