新型相转移催化剂—溴化聚乙二醇基三辛基双季铵的合成

本文合成了新型相转移催化剂－溴化聚乙二醇基三辛基双季铵，该双季铵盐含有双季铵官能团，又有聚乙二醇基。并研究了它的相转移催化性能，获得满意结果。     

芳香族铁电液晶的相变

研究(+)-对烷氧基苯甲酸对′-2-甲基丁氧基苯酚酯液晶和(+)-对烷氧基苄又对′氨基肉桂酸-2-甲基丁酯液晶的铁电相变性质。铁电液晶的自发极化强度(P_s)和其分子倾斜角(θ)与液晶温度(T)的关系相似。随着T升高,P_s和θ减小,T达到居里温度(T_c)附近时P_s和θ均连续地变为零,且介电系数发生突变,出现介电反常,这说明在T_c附近发生结构二级相变。研究还表明,在铁电相范围内属铁电耦合,在顺电相范围内属介电耦合。     

轴矢量介子f_1(1282)在(πωf_1)手征孤立子模型中的效应

通过比较 (πω)和 (πωf1)手征孤立子模型中介子场量的静态解 ,考察了在两种参数确定方式下的轴矢量介子f1(12 82 )对于手征孤立子转动惯量和重子多重态质量劈裂的效应。结论是 :f1的效应很小 ,因此以往忽略 f1的研究是近似合理的     

脂肪醇乙氧基化窄分布催化剂

介绍了近年来脂肪醇乙氧基化窄分布催化剂的研究进展，讨论了酸碱催化剂的催化机理，以及以碱土金属为主体的双组分、多组分催化体系在控制和窄化分子量分布方面的研究成果，同时简要评述了其发展趋势。     

超声沉淀法制备CuO-Fe_2O_3纳米粉体催化剂

采用超声沉淀法制备了标题纳米粉体催化剂 ,运用 XRD、IR、TEM等技术研究了粉体的组成 ,相结构、颗粒粒径及催化分解 H2 O2 活性 .结果表明 ,将超声辐射引入氧化物催化剂的沉淀法制备过程 ,可显著提高催化剂性能 .文中对其原因作了初步讨论 .     

联二萘酚衍生的手性二胺催化剂催化的丙酮与α酮酸酯不对称Aldol反应及机理研究

报道了一种新型的手性二胺化合物，催化丙酮与α酮酸酯的不对称直接Aldol反应，以高达99％的产率和96％的对映选择性得到手性三级醇化合物．通过密度泛涵方法计算得到了四个立体异构过渡态的优化构型及其相对能量，推测了该不对称反应的立体选择性．     

甲醇脱氢制甲醛反应中碱金属难熔盐的催化性能研究

在16 mm陶瓷管固定床反应器中考察了甲醇脱氢制无水甲醛反应中几种含钠化合物及碱金属难熔盐的催化活性,表明陶瓷管也可做甲醇脱氢反应器;碱金属碳酸盐大都具有一定的催化活性,催化性能排序为:Na2CO3>K2CO3>Cs2CO3>Li2CO3,即含钠盐的催化活性较其它碱金属要高;钠的卤化物及硫化物的催化活性很低;钠的含氧酸盐在反应中的催化性能表现各异,其中Na2CO3、Na2B4O7和Na2MoO4的催化性能最好。     

单轴手征媒质电磁带隙结构的色散特性

建立了分析双各向异性媒质电磁带隙结构的平面波展开法普适模型，并对单轴手征媒质电磁带隙结构(以本构参数单轴化了的手征媒质为背景材料并按菱形晶格钻孔)进行了仿真计算．计算结果表明，在横向介电常数相同的条件下，介电常数正单轴化了的手征媒质(其他参数仍为各向同性)电磁带隙结构所具有的全向全极化带隙宽度比各向同性手征媒质的带隙宽度要宽得多，这一发现，为电磁带隙结构的工程应用提供了新的材料选择。     

Applications of M/N/C analogue catalysts in PEM fuel cells and metal-air/oxygen batteries: Status quo,challenges and perspectives

To meet the sharp increase in demand for clean and renewable energy, it is necessary to develop new energy-conversion and storage technologies, such as proton exchange membrane fuel cells (PEMFCs) and metal-air/oxygen batteries (MABs). Due to the sluggish reaction kinetics of the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) in the cathodes of PEMFCs and MABs, significant amounts of precious metal catalysts need to be used, driving up the cost of fuel cells and MABs and thereby hindering their commercialization on a large scale. Transition metal and nitrogen co-doped carbonaceous catalysts (M/N/C) have high catalytic activity towards the ORR and OER once the catalysts are modified with certain promoters/additives. In addition, M/N/C catalysts can be prepared from abundant, inexpensive materials, making their cost negligible compared with precious metal catalysts, a development that would efficiently decrease the cost of PEMFCs and MABs. In last decade, numerous researchers have attempted to realize these applications of M/N/C catalysts, and some exciting results have been achieved, making these promising replacements for precious metal catalysts. However, some serious problems and significant challenges remain. In this paper, we review the research on the application of M/N/C analogue catalysts in PEMFCs and MABs in the last 10 years, indicate the remaining challenges, and suggest the future research directions.     

Morphology controllable synthesis of Pd/CeO2–ZrO2 catalysts and its structure-activity relationship in three-way catalytic performance

CeO₂–ZrO₂ mixed oxides with controlled morphologies (i.e., nanorod, nano-polyhedral and disordered shape) were synthesized through either hydrothermal or coprecipitation method, and the corresponding supported Pd/CeO₂–ZrO₂ catalysts were also prepared by conventional impregnation. The obtained catalysts were subjected to systematic structural/physio-chemical characterizations as well as three-way catalytic performance evaluations. The results showed that CeO₂–ZrO₂ mixed oxides presented different exposed crystal planes: namely disordered CZ-di mainly exposed (111) crystal planes, nanorod CZ-ro mainly exposed (111) crystal planes and few (100) crystal planes, while nano-polyhedral CZ-po exposed both (111) and (100) crystal planes. Clear structure-activity relationship could be demonstrated between the TWC (Three-way catalysts) performance of Pd/CeO₂–ZrO₂ and such different microstructures, as (100) and (111) crystal planes exposed by CZ-ro and CZ-po were beneficial for the surface oxygen vacancies formation, thus increasing the Pd-support interaction and effectively decreasing the light-off temperature of HC and NO elimination. On the other hand, the disordered CZ-di retained more lattice oxygen content, leading to better catalytic activity of CO elimination for the corresponding Pd/CZ-di catalyst.