零地电压偏高的危害及解决方法

在信息设备的使用过程当中,零地电压过高是影响设备使用的一个重要问题。零地电压的偏高会引发设备故障,影响信息设备的使用寿命。本文从零地电压偏高的危害、形成原因及控制三个方面进行了详细分析,结合工作经验,提出了具体的应对方法。     

A New and Efficient Synthesis of Wedelolactone Derivatives

A new and facile method based on an intermolecular cycloaddition was described for the synthesis of wedelolactone derivatives.     

Candida rugosa Lipase－catalyzed Kinetic Resolution of Hydroxyalkanephosphonates

An efficient lipase-catalyzedenantioselective hydrolysis of butyryloxyalkanephosphonates in water-equillbrated diisopropyl ether was developed. The relationship between the substrates‘ structure and the reactivity, as well as the enantioselectivlty of this enzymatic transformation was studied. The catalytic preference of crude Candida rugosa lipase toward such molecules was assigned according to modified Mosher‘s method and Xray crystallographic analysis. Optically pure 2-hydroxy-2-arylethanephosphonates, 3-hydroxy-3-phenylpropanephosphonate, and 3, 3, 3-trifluoro-2-hydroxypropanephosphonates were conveniently prepared in this manner.     

Lipases-Catalyzed Alcoholysis for the Preparation of Chiral 1-or 2- Hydroxyalkanephosphonates

Enzymatic alcoholysis has been developed for the preparation of some chiral 1-and 2-hydroxyalkanephosphonates with high optical purity.This method ensures the convenient access to the optically pure phosphocarnitine,phosphogabob and phosphomycin.     

网络路由交换关键技术分析

在计算机网络体系结构中,路由交换技术作为一项重要的技术,对于网络整体的作用很关键。它不仅在硬件连接和软件通信方面是不可缺少的,而且在改善用户体验和功能实现等方面也作用很大。随着网络的进一步发展,分析研究更适合的技术和应用趋势,对于促进网络和信息技术进步,是必不可少的一项工作。     

动态路由在多校区校园网的设计与实现

高校校园网的建设工作非常重要,随着网络技术在同步发展。在多校区校园网的建设过程中,要根据网络平台的实际要求,根据校园网的智能快捷要求,选择合适的网络技术。建议通过动态路由技术的恰当引入,实现本校区和分校区之间的有效连接,提升传输效率,实现远程教学和数字图书馆的智能化业务。研究多校区校园网建设中,动态路由的设计与实现途径,可以在理论上指导相关技术工作。     

Lipases-Catalyzed Alcoholysis for the Preparation of Chiral 1- or 2-Hydroxyalkanephosphonates 

Ｃｈｉｒａｌ 1 ｏｒ 2 ｈｙｄｒｏｘｙａｌｋａｎｅｐｈｏｓｐｈｏｎａｔｅｓｓｈｏｗｉｎｔｒｉｇｕ ｉｎｇｐｒｏｐｅｒｔｉｅｓｉｎｂｉｏｌｏｇｙａｎｄｏｒｇａｎｉｃｃｈｅｍｉｓｔｒｙ .1Ｔｈｅｔｒａｄｉ ｔｉｏｎａｌｓｙｎｔｈｅｔｉｃｒｏｕｔｅｌｅａｄｉｎｇｔｏｓｕｃｈｃｏｍｐｏｕｎｄｓｓｏｍｅｔｉｍｅｓｈａｓｄｒａｗｂａｃｋｓｓｕｃｈａｓｈａｒｓｈｒｅａｃｔｉｏｎｃｏｎｄｉｔｉｏｎｓ ,ｅｘｐｅｎｓｉｖｅｒｅａｇｅｎｔｓａｎｄｌｏｗｃｈｅｍｉｃａｌｙｉｅｌｄｓ .2 Ｔｏｅｘｐｌｏｒｅｎｅｗａｎｄｃｏｎｖ…     

GSM移动通信无线网络掉话分析

本论文主要介绍了GSM系统结构及网络组成,研究了无线掉话问题的产生原因,同时对掉话计算公式进行了深入分析。     

Regio-and Stereo-selective Bioreduction of Diketo-n-butylphosphonate by Baker''''s Yeast

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｂａｋｅｒ’ｓｙｅａｓｔ (Ｓａｃｃｈａｒｏｍｙｃｅｓｃｅｒｅｖｉｓｉａｅ)ｉｓｗｅｌｌｒｅｃｏｇｎｉｚｅｄａｓａｖａｌｕａｂｌｅｓｔｅｒｅｏｓｅｌｅｃｔｉｖｅｒｅａｇｅｎｔｉｎｂｉｏ ｔｒａｎｓｆｏｒｍａｔｉｏｎｓｏｆｏｒｇａｎｉｃｍｏｌｅｃｕｌｅｓ .Ｔｈｅａｓｙｍｍｅｔｒｉｃｒｅ ｄｕｃｔｉｏｎｏｆｃａｒｂｏｎｙｌｇｒｏｕｐｓｗｉｔｈｔｈｉｓｍｉｃｒｏｂｅｈａｓｂｅｅｎｓｔｕｄｉｅｄｅｘｔｅｎｓｉｖｅｌｙ .Ｍｏｒｅｏｖｅｒ,ｉｎｔｈｅｃｏｕｒｓｅｏｆｒｅｄｕｃｔｉｏｎｏ…