含L－氨基酸结构的手性液晶化合物的合成及其相变行为

合成了９种具Ｌ－氨基酸衍生物结构的介晶化合物（Ｉ－Ⅲ，Ⅳａｂ，Ⅴａ，ｂ，Ⅵａ，ｂ）、４种氨基酸衍生物（Ａ１－４）和６种介晶化合物（Ｍ１－６）．新化合物（Ⅰ－Ⅲ，Ⅳａ，ｂ，Ⅴａ，ｂ，Ⅵａ，ｂ，Ａ４，Ｍ３－６）的化学结构通过ＩＲ、１ＨＮＭＲ和元素分析证实；并用偏光显微观察和ＤＳＣ分析研究了其相变行为，结果表明有８种化合物（Ｍ３－６，Ⅵａ，ｂ，Ⅴｂ，Ⅵｂ）呈现液晶相变。测定了它们的比旋光度。通过Ｘ射线衍射研究了化合物Ⅵｈ１２０～１３０℃和Ⅵｂ１７０～１８０℃的近晶结构，Ⅵｂ显，Ⅵｂ呈。测定了化合物Ⅳｂ的电滞回线，证明其具铁电性。     

聚苯基膦酸双酚A酯的合成与表征

聚苯基膦酸双酚Ａ酯的合成与表征唐旭东陈晓婷王玉忠杨科珂王波（四川联合大学化学系成都６１００６４）吴大诚（四川联合大学轻纺学院成都６１００６５）关键词聚膦酸酯，阻燃剂，熔融缩聚，热性能聚膦酸酯类化合物是一类重要的磷系阻燃剂［１～３］，与传统的非聚...     

Evaporation behavior of water from aqueous dispersions of multihollow particles prepared by the stepwise alkali/acid method

In order to clarify the formation mechanism of multihollow structures inside styrene–methacrylic acid copolymer particles prepared by the stepwise alkali/acid method, which we proposed in 1990, the evaporation behavior of water from aqueous dispersions of the original carboxylated particles and those after the alkali treatment and the stepwise alkali/acid treatments was examined. It is concluded that the particle after the alkali treatment had a number of small water pools inside. Received: 22 February 2001 Accepted: 20 June 2001     

Organic–inorganic nanocomposites prepared from fluoro-aramid and silica

Fluoro-aramid-based sol/gel-derived nanocomposites were synthesized by condensing a mixture of 4,4′-(hexafluoro-isopropylidene)dianiline and 1,3-phenylenediamine with terephthaloylchloride (TPC) in dimethylacetamide. TPC was added in slight excess to produce amide chains with carbonyl chloride end groups and then replaced with alkoxy groups using aminophenyltrimethoxysilane to develop bonding with the silica network. Mechanical, dynamic mechanical thermal, water absorption and morphological measurements were carried out on the thin hybrid films. Increase in the tensile strength and modulus was observed as compared to pristine polyamide. The thermal decomposition temperature was found in the range of 400–500 °C. The water absorption was found to be reduced with higher silica content. The glass transition temperature and the storage moduli increased with increasing silica concentration. The maximum increase in the T _g value (345 °C) was observed with 20 wt% silica. Scanning electron microscopy revealed the uniform distribution of silica in the matrix with an average particle size ranging from 8 to 50 nm.     

Photo-induced Charge Separation of p-Tricyanovinyl-N,N-Dialkylanilines

In this paper,p-tricyanovinyl-N,N-dialkylanilines were synthesized as model compounds and through their spectroscopic behavior,the photo-induced electron transfer,charge separation were discussed and the aggregation in DMSO-H_2O system was investigated.     

Geometric critical exponent inequalities for general random cluster models

A set of new critical exponent inequalities,d(1 –1 /)2 –, dv(1 – 1/), andd> 1, is proved for a general class of random cluster models, which includes (independent or dependent) percolations, lattice animals (with any interactions), and various stochastic cluster growth models. The inequalities imply that the critical phenomena in the models are inevitably not mean-field-like in the dimensions one, two, and three.The present work was reported at the 56th Statistical Mechanics Meeting (Rutgers, December 1986).     

Critical behavior of the two-dimensional first passage time

We study the two-dimensional first passage problem in which bonds have zero and unit passage times with probabilityp and 1–p, respectively. We prove that as the zero-time bonds approach the percolation thresholdp _c, the first passage time exhibits the same critical behavior as the correlation function of the underlying percolation problem. In particular, if the correlation length obeys(p) ¦p–p _c¦^–v, then the first passage time constant satisfies(p)¦p–p _c¦^v. At p_c, where it has been asserted that the first passage time from 0 tox scales as ¦x¦ to a power with 0<<1, we show that the passage times grow like log ¦x¦, i.e., the fluid spreads exponentially rapidly.     

聚乙烯醇高含水胶固定化脲酶的研究

冷冻-部分脱水法制成的聚乙烯醇高含水胶固定化脲酶活力收率及对脲素的分解能力明显高于聚丙烯酰胺囱定化脲酶,稳定性相近;用低浓度的戊二醛后处理,提高了固定化酶的稳定性。     

柠檬酸铝/聚丙烯酰胺胶态分散凝胶反应动力学和机理的研究

采用粘度法研究了柠檬酸铝（AlCit)与部分水解取丙烯酰胺（HPAM）胶态分散凝胶体系的反应动力学。结果表明，胶态分散凝胶体系的交联反应是一级反应。并推导出胶态分散凝胶体系的反应动力学方程。     

以铜离子为模板的褐藻酸凝胶对铜离子的选择性富集研究

以铜离子为模板，制备了褐藻酸凝胶（Cu-alginate)，通过吸附实验及过柱渗滤实验，试验了该吸附剂对铜离子的选择性吸附性能，并且采用该吸附剂富集了自来水中微量的Cu^2 ，结合原子吸收法测定了水样中Cu^2 的含量。结果表明：该吸附剂对Cu^2 有较高的选择性吸附性能，显著优于一些化学合成铜离子模板缩聚物及非铜模板褐藻酸凝胶（如Ca-alginate),非重金属离子（如K^ 、Na^ 、Ca^2 ）及某些重金属离子（如Ni^2 、Cd^2 ）等对Cu^2 的吸附均不产生明显干扰。用该吸附剂富集水中的微量铜离子，回收率可达97.7%。