FREE STANDING FILM OF POLYANILINE

A free standing film of polyaniline as large as 18 cm×18cm×0.002 cm can be obtained by evaporation of a solution of the chemically synthesized base in NMP. Its structure was examined by the elemental analysis, IR, U.V.-visible spectra, XPS, DSC, SEM and X-ray scattering and its conducting behavior as well as electrochemical properties were studied. Results show that the composition, structure of main chain, physical properties of the free standing film of polyanilme is similar to that of the powder. However, some differences in its electronic structure, conductivity at room temperature and potential of redox couple between the flee standing film and powder are observed, which may be due to cross-linking of the film of polyaniline.     

一种新型侧链液晶聚合物的喇曼光谱研究

The Raman scattering on a novel liquid crystal side chain polymer, poly-2,5-bis (p-meth-oxybenzoyloxy) styrene, has been performed. We observed that the characteristic Raman sp-ctra of the vinyl group in the monomer changed much deeply in the polymer, especially for the Raman line correponding to the C=C of the vinyl group which disappeared completly in the polymer. Contrast with that, the Raman spetra of the rest group did not present any substantial difference between the monomer and the polymer. These experimental facts show-ed that the vinyl group of the monomer was tranfered to the polymeric backbone while the chemical structure of the mesogenic unit in the monomer remained after the polymerization,and also conformed that it was successful in the synthesis of a liquid crystal side chain plymer without a flexible spacer between the mesomorphic unit and the molecular main chain.     

DIELS-ALDER REACTIONS OF FURAN WITH DIENOPHILES CATALYZED BY YbCl3

The yield and stereoselectivity of the Diels-Alder reactions between furan(or 2-methylfuran)and different dienophiles are markedly enhanced by the catalysis of anhydrous YbCl₃.     

卤化银乳剂微晶体的结构与性能研究 Ⅶ.切角立方体乳剂微晶体的核壳复合结构

本工作应用双注仪制备了一系列不同碘含量的切角立方体核壳乳剂,用紫外光度法测定了它们的光吸收,用介电损耗法和微波光导法分别测定了它们的离子电导及光电导。结果表明,乳剂微晶体的光吸收和离子电导率都随着碘含量的增加而增加,光电导也随碘含量增加而增大,光电子衰减遵循二级反应动力学过程。碘的引入以及立方体切角使立方体乳剂微晶体的感光性能成倍地增长。     

哌啶并[2,3-b]哌嗪类衍生物的设计、合成及其抗血小板聚集活性研究

以2,3-二氨基吡啶和2,3-丁二酮为起始原料,经环化、催化氢化和亲核取代反应合成了10个新型哌啶并[2,3-b]哌嗪类衍生物(3a~3j),其结构经¹H NMR、¹³C NMR和HR-MS确证。体外抗血小板聚集活性研究表明,化合物3d、3e、3g、3h和3j具有一定的抗血小板聚集作用,其中化合物3h(IC₅₀=1.24mmol/L)的活性显著优于母体化合物川芎嗪(IC₅₀=3.96mmol/L)和阳性药物阿司匹林(IC₅₀=2.41mmol/L)。     

基于QuEChERS净化/气相色谱法测定蔬菜及水果中16种有机氯农药残留

该文建立了蔬菜及水果中16种有机氯农药残留的QuEChERS净化/气相色谱快速检测方法.样品经1％冰乙酸乙腈处理,QuEChERS净化,气相色谱分离后,以色谱峰保留时间定性,外标法定量.结果表明:16种有机氯农药在2.0～100 pg/L质量浓度范围内的线性关系良好,相关系数均大于0.99,检出限为0.16～2.90 ...     

芥子气中毒人员尿液标记物谱分析及其临床诊断应用

该研究基于暴露生物标记物溯源思路,应用于解决芥子气(SM)临床早期诊断、溯源确证难题.建立了芥子气中毒患者尿液中7 种游离代谢产物的两步固相萃取/超高效液相色谱-串联质谱(SPE/UPLC-MS/MS)同时定量方法,检出限为5 pg/mL～1 ng/mL,定量下限为10 pg/mL～5 ng/mL;结合前期建立的4 种...     

基于机器学习的直接电离质谱爆炸物检测方法

直接电离质谱系统在现场快速检测中的应用日益广泛,主要用于爆炸物、毒品、食品添加剂等的检测.然而,直接电离质谱系统中质谱信号波动大且同一浓度样品峰强呈现对数正态分布,严重影响了检出限附近低浓度样品的检测准确性.该研究将乙酰水杨酸(115个样品)作为爆炸物模拟物,利用介质阻挡放电离子源与质谱系统,研究了基于机器学习的直接电...     

功能肽段介导的铜离子荧光传感器的构建及应用

铜离子是导致多种疾病(如阿尔茨海默病、朊病毒病和肌萎缩性侧索硬化症等)的重要因素.当前已有针对铜离子检测的相关报道,但基于多肽与铜离子相互作用的荧光传感器鲜有关注.该文依据淀粉样蛋白与铜离子特异性结合的特点,利用已知的淀粉样蛋白组成单元,设计出能与铜离子有序配位的多肽分子(DDAEGHARHCR).同时,借助于"多肽-...     

高精度镉同位素分析样品消解方法对比研究

为考察不同消解方法的优缺点以及对不同基质样品(沉积物和大米)Cd同位素组成的影响,该文采用干法灰化法、酸提取法、微波消解法和高温高压密闭消解法等消解方法对水系沉积物(GSD)进行消解处理,比较了不同消解方法对沉积物Cd同位素组成测定的影响.随后使用微波消解法和高温高压密闭消解法对大米标准物质以及实际大米样品进行了消解....