The chiral oxiranecarboxylic acids or esters 2a-e were obtained with lipase (CCL) in aqueous-organic system.The ee and the absolute configurations of the products were determined.
Based on the theory of generalized exponeatial dichotomies, some typical nonautonomouslinear systems with time-translation parameters or with time-scale parameters are discussed.Conditions of parameters are given to d...Based on the theory of generalized exponeatial dichotomies, some typical nonautonomouslinear systems with time-translation parameters or with time-scale parameters are discussed.Conditions of parameters are given to determine by spectral gaps the generalized exponentialdichotomies of those systems and their local L'-limit systexns. These conclusions are applied tosrvcalled SVC systems and HFO systems for their stability.展开更多
文摘The chiral oxiranecarboxylic acids or esters 2a-e were obtained with lipase (CCL) in aqueous-organic system.The ee and the absolute configurations of the products were determined.
文摘用哈克流变仪混合附件(SYSTEM40)和示差量热扫描仪(DSC,PE—7)研究了混合时间和混合温度对 PC/PET 共混体系相窑性的影响.研究结果表明:共混体系的相容性随混合时间增加或混合温度提高而变化,物料在270℃下混合时间达60min 时,体系由不相容变为楣容;而在280℃时仅混合40min 体系已完全相容。相容体系的玻璃化转变温度符合 Fox 方程.比较不同 PET 含量的共混体系发现:两组含量越接近达完全相容的时间越短。三元共混体系的相容性总是好于二元共混体系。
文摘Based on the theory of generalized exponeatial dichotomies, some typical nonautonomouslinear systems with time-translation parameters or with time-scale parameters are discussed.Conditions of parameters are given to determine by spectral gaps the generalized exponentialdichotomies of those systems and their local L'-limit systexns. These conclusions are applied tosrvcalled SVC systems and HFO systems for their stability.
