膜催化用膜材料

膜催化是在催化化学和膜科学基础上发展起来的新兴研究领域,近年来这方面的研究日趋活跃。膜催化理论和实际应用还处于起始探索研究阶段,受到各国学者的关注。 利用某些材料本身所具有的催化活性,或是将膜作为催化剂的载体,在膜内部或表面固定催化剂,使其具有催化反应功能。用这些材料组装成反应器,用于化工过程,能将反应和分离统一于一个体系内,即在膜上进行催化反应,能使反应过程和分离过程同步进行,     

无机膜与无机膜催化反应

本文对无机膜的制备、应用以及膜催化反应的现状进行了较全面的综述,并对研究工作中存在的问题展开了讨论。     

质子交换膜燃料电池有序化膜电极

质子交换膜燃料电池的核心部件--膜电极经历了两代传统制备方法后,已经进入第三代有序化膜电极发展阶段.有序化膜电极包括质子导体有序化膜电极和电子导体有序化膜电极两大类,而电子导体有序化膜电极包括催化剂材料有序化膜电极和催化剂载体材料有序化膜电极.有序化膜电极具有良好的电子、质子、水和气体等多相物质传输通道,从而可以大大降低膜电极中Pt载量、提升燃料电池的发电性能和延长燃料电池寿命.本文整理了近几年有关有序化膜电极的研究报道,梳理了有序化膜电极研究进展,归纳比较了各种有序化膜电极制备方法的优缺点,对未来高性能、低成本和长寿命的膜电极制备技术开发具有指导意义.     

质子交换膜燃料电池膜电极

介绍了质子交换膜燃料电池膜电极的组成，电极反应，综述了近年来膜电极的研制方法。探讨了该电池电极制作过程的关键问题及技术。     

质子交换膜燃料电池梯度化膜电极

为实现质子交换膜燃料电池的高性能(高功率密度或大电流密度)、低成本(低铂载量)、长寿命发电,人们尝试在燃料电池的核心部件膜电极结构中引入梯度化设计的概念。梯度化膜电极包括膜电极中各组件的梯度化:气体扩散层的PTFE含量与孔隙率的梯度化,催化层的催化剂与Nafion用量的梯度化以及微孔层的疏水性与孔隙率的梯度化。梯度化膜电极中催化剂分布、孔隙率分布、亲/疏水性分布合理,具有良好的三相反应界面以及质子、电子、反应气体、水等多相物质高效传输通道,从而能满足在低铂载量、低加湿以及高电流密度条件下高性能稳定工作。本文整理了近几年来有关燃料电池梯度化膜电极研究的相关文献,梳理了梯度化膜电极研究发展脉络,归纳总结了各种梯度化膜电极的制备方法、性能以及构效关系,并展望了梯度化膜电极下一步研究方向,对高性能、低成本、长寿命的燃料电池开发具有指导意义。     

LB膜

LB(Langmuir-Blodgett)膜由转移漂浮在水面上的单分子层到固体基板上而制备。LB膜与其它膜相比,具有三个显著的特点:膜厚能薄至数十埃甚至数埃;能制备几乎没有缺陷的单分子层膜;高度的各向异性的层结构。这些特点预示着广泛的应用潜力:(1)光学元件的透明层;(2)绝缘层和隧道效应层;(3)电荷     

PSF/SPSF高分子合金膜的膜材料对膜性能的影响

介绍了PSF与SPSF共混对合金膜的成膜性能和机械性能的影响 .二者共混改善了PSF的亲水性 ,提高了PSF膜的耐污染性 ,并且合金膜获得比PSF膜高的渗透通量     

有序分子膜

本文结合作者的研究工作，详细综述了两亲分子的相变、聚集性质及有序分子膜的形成与应用。     

质子交换膜燃料电池膜电极耐久性的提升

质子交换膜燃料电池由于具有能量转换效率高、操作温度低、环境友好等优点而备受人们关注。随着2014年丰田发布燃料电池电动汽车Mirai,带来了新一轮燃料电池及燃料电池汽车的产业化热潮。然而,提升质子交换膜燃料电池的寿命,开发新一代长寿命燃料电池膜电极及燃料电池仍然是本领域的挑战性课题。膜电极(MEA)是质子交换膜燃料电池最核心的部件,其耐久性直接决定着燃料电池的寿命。MEA主要由质子交换膜、催化剂层、气体扩散层三部分组成。本文从质子交换膜、催化剂及载体、气体扩散层三个方面介绍了近年来国内外在提升燃料电池膜电极的寿命(耐久性)方面所做的工作,并对未来的相关研究和发展做了述评及展望。     

黑膜厚度与膜表面张力关系的研究

用微干涉测量技术直接测定楔压等温线,研究了电解质浓度对阳离子表面活性剂TTAB在浓度大于cmc时形成黑膜厚度的影响及膜表面张力与溶液表面张力之间的差别.结果显示,黑膜厚度取决于楔压和电解质浓度,随着楔压的增加,液膜厚度减少至一定程度后几乎保持不变,表明黑膜类型的转化是阶跃式的,而电解质屏蔽了液膜两个表面电荷层间的排斥作用,故电解质浓度增加,液膜厚度变小.由楔压等温线得出的膜表面张力的结果说明一般黑膜的表面张力与溶液的表面张力并无明显差别.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。