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191.
Ping Yan BIE Cheng Lu ZHANG Xuan Jia PENG Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2002,13(9)
Celaphanol A was a diterpene isolated from the stems of Celastrus stephanotifolius1, which have been the subject of continued and growing interest, due to the range of biological activities shown by many members of this family2. Some have been used in traditional medicine3 or as a stimulant4 from ancient times. In order to further study the relationship between the structure and biological activity of the diterpene compound and as an extension of diterpenoid synthesis in our laboratory5, 6, … 相似文献
192.
Li Jun HUANG Yan PANG Ji Mei MIN Li He ZHANG* National Research Laboratory of Natural Biomimetic Drugs Peking University Beijing 《中国化学快报》2001,(7)
Cyclic ADP-ribose (cADPR) 1 (Figure 1), a intracellular Ca2+-mobilizing messenger, is of great interest because of its significant importance in the signal transduction1. However, the biological as well as chemical instability of cADPR limits the studies of its physiological role, at least in some aspect2. Recently, Shuto et.al.3 constructed a mimic of cADPR, cyclic IDP-carbocyclic-ribose 2, in which the 4'-oxo in furanose is substituted by a methylene group and the stability of 2 is i… 相似文献
193.
Cai Hong XU Zhi Jie ZHANG Yong Min LI Zhi Min ZHENG Ze Min XIE* Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences Beijing 《中国化学快报》2001,(1)
Recently, the silicon-nitrogen compounds have received more consideration for their attractive application prospects. Both low molecular weight silazane and polysilazane with high molecular weight are widely used in many aspects. For example, in the processing industry of silicone rubber, silizanes not only can be used as "structure-control additives"1, but also can be used to improve the rubber's heat-resistance and mechanical properties; silicon-nitride ceramics can be prepared by pyrolysis … 相似文献
194.
ZHONG Gui yun LIU Hua XIE Qing lan * Institute of Elemento organic Chemistry Nankai University Tianjin P. R. China 《高等学校化学研究》2002,18(3):277-279
IntroductionThe drug- molecules are called as silyl- drug ifasilicon atom replaced one carbon atom of theorganic- drugs.Generally,they have low toxicityand pro- long efficiency.Many methods have beendesigned in order to decrease the toxicity oforganotin compounds and organosilicon which hasbeen proved to be effective.Torque[1] is a newacaricide made by America Shell Company,itsmolecular formula is [( Ph Me2 Si CH2 ) 3 Sn]2 O.Tacker[2 ] synthesized the compounds( Ph Me2 Si CH2 ) 3 Sn X[… 相似文献
195.
WANG Bai Jing WEI Min ZHANG Li Ping * School of Life Science Northeast Normal University Changchun P.R. China 《高等学校化学研究》2003,19(1):37-40
IntroductionBoth Cordycepsmilitarvs( L.) Link and Cordy-ceps sinensis Sacc belong to the claviceps purpureafamily cordyceps genus,and Cordyceps sinensisSacc has received much attention because of its spe-cial function.But the scarcity of it in quantity andthe difficulty of it to be cultivated have made theapplication of this kind oforganism limited.Cordy-ceps militarvs( L .) Link is relatively easier to becultivated. What is more,the determination ofpharmaceutical chemistry and pharmacolog… 相似文献
196.
3-氯-1,2-环氧丙烷的同步辐射光电离 总被引:1,自引:0,他引:1
杂环类化合物在自然界中分布十分广泛,且许多具有生物活性,它们大多数在生物的生长 发育、遗传和衰亡过程中起着关键的作用[1,2].含氧三元杂环体系是最基本、最简单的杂环化合 物,分子中的含氧三员环,具有很大的张力,且存在很强的极性共价键,使其易于发生定向开环 反应,具有高度反应性.利用光电高质谱法对这类分子进行光电离与光离解研究,可以获得这 类物质一些重要的物理化学数据. 我们已对环氧乙烷和环氧丙烷进行了光电离和光离解研究,并结合量化理论计算分析了 它们的光电离解离通道[3,4],3-氯-1,2-环氧丙… 相似文献
197.
Wei Jiang HE Fang LIU Zhi Feng YE Zi Jian GUO Jun Bai LI Long Gen ZHU* State Key Laboratory of Coordination Chemistry Nanjing University Nanjing Laboratory of Colloid Interface Science Center for Molecular Science Institute of 《中国化学快报》2000,11(11)
Since calixarenes and their derivatives have unique coordination abilities to metal ions and inclusion abilities toward neutral organic molecules, they have been widely studied in the field of molecular recognition, transportation and separation1. In order to explore these functions, membranes such as monolayers and Langmuir-Blodgett (LB) films formed by calixarenes, are often used for these purposes2-6. However, a crucial factor that hinders their application is the weak mechanical strength … 相似文献
198.
Ng Seik Weng~* 《结构化学》2000,(6)
1 INTRODUCTIONSeveralincorrectspacegroupshavebeenre assignedbymakinguseofsimulatedstructurefactors;however,thecruxofthisoranyspacegrouprevisionistheaccuratereportingofthespacegroupandatomiccoordinatesoftheincorrectlydeterminedstructuresincethetruestruc… 相似文献
199.
1 INTRODUCTIONAbscisicacid(ABA)isoneofplanthormoneswhichwasisolatedfromyoungcottonfruitsin1963[1].Itnotonlyinhibitsplantgrowth,butalsoprotectsplantsa-gainstdeprivationofwaterduringdroughtdays[2].Hydroxyalkylphosphonicacidsandtheirderivativesappeartobeveryimportantfortheirwidebiologicalactivitiesintheinhibitionofenzymes,fungicidesandplantgrowthregulation[3].Wedesignedandsynthesizedthetitlecompound4,theunsaturatedphosphonateanaloguesofABA,whichexhibitsplantinhibitoryactivityontheelongati… 相似文献
200.
在科技文献中,地震常被比喻为非线性动力学过程或统计物理中的相变过程.文章探讨了如何从非线性力学中的分岔理论以及统计物理内的朗道相变理论出发,从势磊穿越,临界涨落与临界慢化等多个角度来分析和了解地震发生的全过程.文章作者试图在这些非线性力学与统计物理的基础上,综合地震过程中在时间与空间上应出现的前兆,解释如何可能做出具有普适性的数值地震预测. 相似文献