Ab Initio Study on the Isomerization and Dehydrogenation of Methylnitrene

The ab initio calculations were performed at the RHF/4-31G level with the reaction pathways of the iso-merization and dehydrogenation of methylnitrene by the intrinsic reaction coordinate method. The results show that the transformation from methylnitrene to methylenimine would be very easy. This accountes for the experimental fact that one couldn' t find the methylnitrene, but only obtained the methylenimine in the pyrolysis of methyl azide. The mode-selective study reveals the reaction coordinates (IRC) of isomerization and dehydrogenation of methylnitrene are associated with the molecular deformation mode of 1191 cm-1 and the methyl group unsymmetrical stretch mode, respectively. The coupling between normal coordinates is favourable to select the reaction channel of isomerization.     

纳米粒子在乙炔聚合反应中的催化作用

纳米粒子在乙炔聚合反应中的催化作用王彦妮，张志琨，崔作林（青岛化工学院纳米材料研究所，青岛２６６０４２）关键词纳米粒子，乙炔，聚合反应，催化作用纳米粒子具有较大的比表面积，因而具有传统材料所没有的独特的光、电、磁等性能．对纳米粒子的研究始于６０年代．...     

STATISTICS OF A NOVEL CLASS OF LIQUID CRYSTAL POLYMERS

A novel class of the liquid crystal polymers with mesogens laterally attached to flexible main chain backbones has been synthesized recently by us. While the flexible backbones tend to take configuration of maximum entropy the mesogenic side groups tend to orientate because of the anisotropie soft dispersion forces. A mean field theory is presented to describe the competition between these two trends which makes it possible for this class of polymers to show anisotropic (liquid crystal) phase within certain temperature range where the polymer main chains and the side chain mesogens will take approximately parallel arrangement, which is different from the normal side chain liquid crystal polymers. The temperature range of the liquid crystal phase, its ordering and phase transition all depend on the flexibility of the backbone, the strengthof the anisotropic forces of the side groups and the hinge elasticity. The results show that the liquid crystalisotropic phase transition is of the first order. The phase diagram, i. e. the dependence of the transition temperature on the structure of the polymers is also given.     

香兰素及其主要衍生物化学性质的CNDO/2研究

用CNDO/2法研究了香兰素,并对香兰素及其三个主要衍生物的化学性质作了理论分析。结果为合成香兰素系列香料提供了理论依据。     

单丁基磷酸酯的合成与表征

本文报道用三氯氧磷酯化、水解方法制备单丁基磷酸酯，用红外、核磁共振，质谱等方法对其结构进行了分析与表征。     

以meso四-(对磺基苯)卟啉为柱后衍生剂同时测定微量镉、汞、锌的离子色谱法

提出了以TPPS_4为柱后色谱衍生试剂的同时测定微量汞、镉和锌的离子色谱分析法,研究了影响衍生反应速度的因素。在含氯化钠的pH 10.3～12的硼酸钠缓冲介质中,以PAR催化TPPS_4与待测金属离子反应,以硅质键合相阳离子交换剂为固定相、酒石酸—氯化钠为流动相,于10min左右定量分离金属离子并将镉的淋洗顺序调至锌前。用于废水、硅酸盐和大米分析,结果满意。     

SOIL AGGREGATE AND ITS RESPONSE TO LAND MANAGEMENT PRACTICES

This paper provides a broad review of the existing study on soil aggregate and its responses to land management practices. Soil aggregate is used for structural unit, which is a group of primary soil particles that cohere to each other more strongly than other surrounding particles. The mechanism of soil particle aggregation may be expressed by a hierarchical model, which is based upon the hypothesis that macroaggregates （〉250μm） are collections of smaller microaggregates （〈250μm） held together with organic binding agents. Primary particles form microaggregates and then macroaggregates. Carbon （C）-rich young plant residues form and stabilize macroaggregates, whereas old organic C is occluded in the microaggregates. The interaction of aggregate dynamics with soil organic carbon （SOC） is complex and embraces a range of spatial and temporal processes within macroaggregates and microaggregates. The nature and properties of aggregates are determined by the quantity and quality of coarse residues and humic compounds and by the degree of their interaction with soil particles. The mechanisms resulting in the binding of primary soil particles into stable aggregates vary with soil parent material, climate, vegetation, and land management practices. Land management practices, including tillage methods, residue management, amendments, and soil fertility management, enhance soil aggregation. However, there is still much uncertainty in the dynamics of organic matter in macroaggregation and microaggregation, and research is still needed to understand further the mechanisms of aggregate formation and its responses to human activities.     

1,3,5-苯三甲醛的合成与应用研究进展

介绍了1,3,5-苯三甲醛的合成与应用。在1,3,5-苯三甲醛的众多合成方法中,以氧化还原方法最常见,此外水解、聚合等方法各具优点,在满足高产率和绿色化学方面有了更多选择。1,3,5-苯三甲醛是一种具有广泛开发应用前景的化学合成中间体,以其为原料合成的大分子物质具有优异的化学、物理特性和生物活性,在催化、光电、抗病毒,以及分子吸附和药物包材等方面具有广泛的应用。     

苯并咪唑取代胺类及其金属配合物的研究与应用

概述了双苯并咪唑取代胺类、三苯并咪唑取代胺类及四苯并咪唑取代胺类配体及其金属配合物的研究和应用。研究报道,这些配体与人体必需的微量元素铜、锌、钴、镍、锰等金属形成的配合物能较好地模拟SOD分子中与金属离子配位的组氨酸的结构,且具有较好的拟SOD生物活性。