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991.
Y Z Gunata C L Bayonove R E Cordonnier A Arnaud P Galzy 《Journal of the science of food and agriculture》1990,50(4):499-506
The exocellular β-glucosidases of Candida molischiana and Candida wickerhamii are able to hydrolyse geranyl, neryl, citronellyl, linalyl and α-terpinyl-β-D -glucopyranosides. The nature of the aglycone residue greatly affects the rate of hydrolysis. Glucosides with a tertiary alcohol as aglycone residue are more slowly hydrolysed than those with a primary alcohol. The β-glucosidase from C molischiana is also able to hydrolse α-L-arabinofuranosides. This results in the release of monoterpenols from a glycoside extract from grape juice. 相似文献
992.
在室内试验的基础上研究了碾压混凝土全级配及过湿筛的本体与层间结合试件渗透系数、及与抗渗标号的关系,对碾压混凝土的渗透性及其影响因素进行了分析。 相似文献
993.
根据清水下泄引起的河床变形过程的模型试验,运用泥沙连续方程,引入了以反映瞬时冲淤量的特征速度概念,导出了推移质输沙的平衡过程方程。再结合水流的圣维南方程、河床变形方程,对试验结果进行了数值模拟。 相似文献
994.
系统层次灰关联分析与应用 总被引:2,自引:0,他引:2
将灰色系统分解为若干灰色分系统,进而提出了系统层次灰关联分析法,计算表明,该方法用于水电工程排序以及多层次水利水电规划设计方案的优选是一条新的可行的途径。 相似文献
995.
简述涡管排沙式沉沙池的设计思路 ,结合新疆金沟河渠首电站 ,介绍涡管排沙式沉沙池的原型观测结果 ,并对沉沙池的运用效果进行了分析 .工程实践表明 ,涡管排沙式沉沙池构造简单 ,运行可靠 ,造价低廉 ,有较好的沉沙及排沙作用 ,可用于排除水电站引水渠道中的悬移质泥沙 相似文献
996.
深层搅拌水泥土防渗墙在堤防工程中的应用 总被引:1,自引:0,他引:1
水泥土搅拌法是一种技术可靠、工艺简单、高效低耗及环保的软土地 固新方法,以其在黄冈长江干堤加固工程中的应用为基础,分析了采用该工法建造水泥土防渗墙的原理,并对其中存在的一些问题进行了探讨。 相似文献
997.
How do academic activities and discourse work together in classrooms to shape learning and instruction? This complex question was answered in a case study of underachieving students in a Grade 8 history class. Data were collected through class observation and interviews with experienced teachers and students in 2 classrooms. Teachers taught history content and learning strategies. Theories of social constructivism predict that the discourse arising before, during, and after activities can explain variability in students' social and academic participation in curriculum events, as can the nature of the instructional approach students experience when teachers hold similar goals. Patterns of co-occurring forms of discourse and activities across sequences of lesson events provided a useful window into interactions between learning and instruction. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
998.
Marilia Panayiotou 《Polymer》2005,46(3):615-621
Stimuli-responsive poly(N,N′-diethylacrylamide) gels were prepared by free radical polymerisation in aqueous solution, using N,N-methylenebisacrylamide as crosslinking agent. The gels were compared with the corresponding poly(N-isopropylacrylamide)-based gels. In particular, the swelling ratio of both gel types including the effect of the crosslinker content, their swelling and deswelling kinetics, their permeability and finally their drug (insulin) storage and controlled release ability were compared. In spite of the similarity in the monomer/crosslinker ratio, the deswelling kinetics and the critical temperatures (ca. 30-32 °C in pure water), some differences could be observed. Compared to poly(N-isopropylacrylamide)-based gels, poly(N,N′-diethylacrylamide)-based gels show a broader phase transition temperature interval, a more pronounced dependency of the swelling ratio on the crosslinker content, slower reswelling kinetics, a higher ingress percentage for dextran standards ranging from 5 to 70 kD, but lower ingress percentages for proteins (BSA, insulin) and much faster drug (insulin) release kinetics. While a non-linear release kinetic was observed in the case of the poly(N-isopropylacraylamide)-based gels both in water and in PBS (phosphate buffered saline), this was not the case for the poly(N,N′-diethylacrylamide)-based gels. 相似文献
999.
Cypriano G da Trindade Neto Ana LP Fernandes Ana IB Santos Waldenice A Morais Marcos VM Navarro Tereza NC Dantas Mrcia R Pereira Jos LC Fonseca 《Polymer International》2005,54(4):659-666
Complexation of chitosan in aqueous solutions by low molecular weight electrolytes is one of the simplest methods for the preparation of aqueous chitosan dispersions. In this work, the influence of storage time, sulfate concentration, method of preparation and surfactant content on some properties of the resultant chitosan dispersions (turbidity, viscosity and zeta potential) was analyzed. Turbidimetry was adequate to monitor the formation of particles, while viscometry was suitable to monitor changes in the dispersing phase. An analysis of the properties of these systems, mainly in terms of particle–particle and macromolecule–macromolecule interactions was carried out. Copyright © 2004 Society of Chemical Industry 相似文献
1000.