在肽库中进行小肽筛选的初步研究

以合成六肽ＤＧＧＳＡＡ为模型对在噬菌体肽库中进行小肽筛选做了初步研究。结果表明，含有可形成氢键和离子键残基的小肽能够在噬菌体肽库中进行筛选。并用明显提高了筛选的专一性。     

新型含氟聚芳醚酮的合成与表征

聚芳醚酮具有很高的热稳定性和优良的电性能及机械性能 ,已经被广泛应用于宇航、电子及核能等高技术领域 [1] .氟元素的引入可以降低材料介电常数、折光指数和吸水率 ,提高热稳定性、溶解性和阻燃性 ,增加材料透明度 ,使这类聚合物在光电子、光学和微电子等应用领域的研究倍受关注 [2～ 4 ] .本文在合成含三氟甲基苯侧基的聚芳醚酮 [5] 的基础上 ,设计并合成了新型的含氟量更高的单体和聚合物 ,并对其性能进行了初步研究 .1　实验部分1 .1　试剂与仪器　 [3,5 -二 (三氟甲基 ) ]苯代对苯醌 (自制 ) ;锌粉 ,A.R.级 ,天津化学试剂一厂产品 ;…     

Failure of elastomeric polymers due to rate dependent bond rupture

A new cohesive zone model is developed in order to study the mechanisms of adhesive and cohesive failures of soft rubbery materials. The fracture energy is estimated here using a strategy similar to that of Lake and Thomas (LT) by considering the dissipation of stored elastic energy followed by the extension and relaxation of polymer chains. The current model, however, departs from that of LT in that the force needed to break an interfacial bond does not have a fixed value; instead, it depends on the thermal state of the system and the rate at which the force is transmitted to the bond. While the force required to rupture a chain is set by the rules of thermomechanically activated bond dissociation kinetics, extension of a polymer chain is modeled within both the linear and nonlinear models of chain elasticity. Closed form asymptotic solutions are obtained for the dependence of crack propagation speed on the energy release rate, which are valid in two regimes: (I) slow crack velocity or short relaxation time for bond dissociation; (II) fast crack velocity or long relaxation time for bond dissociation. The rate independent and the zero temperature limit of this theory correctly reduces to the fracture model of LT. Detailed comparisons are made with a previous work by Chaudhury et al. which carried out an approximate analysis of the same problem.     

稀土金属作用下芳香醛、酮的还原偶联反应

由Ln/ROH/TMSCl组成的体系能选择性地使芳香族醛、酮还原偶联形成频哪醇, 产率优良, 而对脂肪族醛酮呈惰性。     

Octahedral cobalt(III) complexes of the chloropentammine type. XVII. Association and reaction of some halogenopentamminecobalt(III) and halogenopentamminechromium(III) cations with hydroxide in aqueous dioxan

The replacement, by hydroxide ion, of the coordinated halide from some halogenopentamminecobalt(III) and -Chromium(III) cations in aqueous dioxan has been studied over a range of alkali concentrations up to 0.1 M. With excess of hydroxide ion at constant ionic strength, pseudo first-order rate constants were obtained. The results support a pre-equilibrium association of complex and hydroxide ions in these media, but do not provide distinction as to whether the resulting ion-pair subsequently reacts by direct exchange or by proton removal. The extents of ion association are found to be greater for the cobalt(III) than for the chromium(III) system, increasing with the amount of dioxin in the solvent mixture.     

3-氨基环己基甲酸和cis-3-氨基环己烯基-5-甲酸立体异构体的合成

通过手性胺拆分方法，从3-环己烯基甲酸出发分别合成得到了3-氨基环己基甲酸（ACHC）的四个立体异构体，以及cis-5-氨基-3-环己烯基甲酸（ACHEC）的二个立体异构体。     

偏钛酸型锂离子交换剂固相合成反应动力学

偏钛酸型锂离子交换剂固相合成反应动力学钟辉＊郭灵虹（成都理工学院应用化学系成都６１００５９）（四川联合大学分析测试中心成都）关键词偏钛酸锂，离子交换剂，合成，固相反应动力学１９９７－０８－２５收稿，１９９７－１２－１０修回四川省应用基础研究基金资助项...     

Two Novel Alkaloids from Zanthoxylum nitidum

Two novel alkaloids, 4,5‐dihydroxy‐1‐methyl‐3‐oxo‐2‐(trichloromethyl)‐3H‐indolium chloride ( 1 ) and 4‐(2‐methoxyethyl)‐N,N‐dimethylbenzenamine ( 2 ), were isolated from the EtOH extract of the roots of Zanthoxylum nitidum. Their structures were identified on the basis of spectroscopic and mass‐spectrometric analyses.     

聚氯乙烯复合热稳定剂中铅镉钡的同时测定

聚氯乙烯（PVC）材料广泛应用于建筑、电讯、交通、电子、化工、包装等行业。然而，PVC加工时存在着一个致命的弱点，就是其流动温度为136℃，分解温度为140℃，两者相差仅4℃，给加工带来很大难度，为了能顺利加工就必须加入热稳定剂，热稳定剂是PVC加工不可缺少的主要助剂之一。热稳定剂种类繁多，我国目前大量使用的稳定剂为铅盐及金属皂等稳定剂，产量高达4．5万吨。由于铅、镉、钡等金属元素具有一定的毒性，使用中易造成环境污染，有害于人体健康，因此必须严格加以控制。     

丙烯酸甲酯/4-丙烯酰胺基-2,2,6,6-四甲基哌啶光共聚合体系的竞聚率和序列分布研究

以丙烯酸甲酯(MA,M1)和4-丙烯酰胺基-2,2,6,6-四甲基哌啶(AATP,M2)溶液光共聚合体系为研究对象,采用1H-NMR手段测定了MA/AATP共聚物的组成,用Mayo-Lewis积分法和扩展Kelen-Tüdos方法计算的竞聚率分别为0.88相似文献