Telechelic polymers by living and controlled/living polymerization methods

Telechelic polymers, defined as macromolecules that contain two reactive end groups, are used as cross-linkers, chain extenders, and important building blocks for various macromolecular structures, including block and graft copolymers, star, hyperbranched or dendritic polymers. This review article describes the general techniques for the preparation of telechelic polymers by living and controlled/living polymerization methods; namely atom transfer radical polymerization, nitroxide mediated radical polymerization, reversible addition-fragmentation chain transfer polymerization, iniferters, iodine transfer polymerization, cobalt mediated radical polymerization, organotellurium-, organostibine-, organobismuthine-mediated living radical polymerization, living anionic polymerization, living cationic polymerization, and ring opening metathesis polymerization. The efficient click reactions for the synthesis of telechelic polymers are also presented.     

水坝安全管理:溃坝模式之挑战与契机

潜在溃坝模式分析方法论(PFMA Methodology),是对水坝系统进行安全风险"总体检"所采用的一种高、广且深的新分析管理工具.PFMA不仅是方法论技术本身(硬件)的应用,也是使用和发展该项技术配套观念(软件)的建立与延伸.简言之,除娴熟该方法论之外,PFMA技术应用是否成功,还建立在水坝安全管理人员全面的专业素质基础上,包括专业技术和敬业精神,以及与人和谐相处、共同努力达成工作目标的团队精神.本文提供几种不同坝型在PFMA方法的框架下,考虑静力、水文和地震三种荷载,可能发生的PFMs以及相应措施的范例,供读者参考之用.