化学过程

When the molecular force field was used to treat solution systems, not considering the movement of electrons, in many force fields the chemical bonds between atoms must be confirmed to make sure that they can't be destroyed or formed in modeling procedure.

在用分子力场来处理溶液体系的时候由于没有考虑电子的运动，所以在很多力场中，原子间的化学键必须确定，以确保在模拟过程中化学键不会破坏或生成。

Methane, oxygen and H_2O molecules are activated, ionized and dissociated into active particles such as CH_3~+, O~-, H_2O~+, CH_3, CH_2, CH, H,OH and O, by nonelastic collision with high energy electrons. The particles react with each other in the reactor to synthesize chemically products including gaseous oxy-hydrocarbons.We study the rule of reaction by changing electrical parameter, gas flow etc. Study the conversion of methane, selectivity of gaseous hydrocarbons and yield of methanol under different reaction condition.

针对常规甲烷催化转化和氧化偶联制备含氧化合物的问题，遵循国际化学科学研究前沿"绿色化学"原则，采用自然界存在丰富的CH_4、H_2O和O_2为原料，在绿色友好的常温大气压无任何催化剂的条件下，采用强电场电离放电加速电子及其激励气体分子的极端物理手段，在反应腔体内进行无任何环境污染的非平衡等离子体化学反应，将气体分子激发、电离、离解成CH_4~+、CH_3~+、CH_4~·、H_2O~+、H_2O~·、O_2~+、O(~1D)等活性粒子，生成气态烃及含氧碳氢化合物，整个反应过程实现零污染、零副产品。

Several transient compounds were synthesized by the homo- and heterogeneous reactions of reactive halogen compounds, In-situ ultraviolet photoelectron spectroscopy and photoionization mass spectroscopy as well as theoretical calculations were used to study their molecular structures, stability and molecular orbital properties, their electronic structures and geometric structures were obtained for the first time; Simultaneously, the electronic structure and thermal dissociation of acetyl peroxynitrate and trifluoroacetyl peroxynitrate which have great importance in the atmospheric chemistry were studied; The substituent effects of series of halopyridines and halothiophenes were studied by the ultraviolet photoelectron spectroscopy method for the first time. The atmospheric chemical reaction between peroxyacetyl radicals with IO radicals as well as the dissociation of the most stable isomer of CH3COIO3 were calculated by density functional theory, it was found that the CH3COOIO2 isomer may be act as a new reservoir of inorganic iodine in the stratosphere.

通过活性卤素的系列均相与非均相化学反应合成了几种瞬态物种，采用原位紫外光电子能谱和光电离质谱结合量子化学理论计算对化合物的分子结构、稳定性以及分子轨道特性进行了研究，首次获得了这些物种的电子结构和几何结构的信息；同时研究了大气中有重要作用的乙酰过氧硝酸酯和三氟乙酰过氧硝酸酯的电子结构性质及热解过程；采用紫外光电子能谱手段首次研究了系列卤代吡啶和噻吩的取代基效应；通过量子化学理论计算研究了乙酰基过氧自由基与IO自由基的大气化学反应及其最稳定异构体CH3COOIO2的解离，发现该物种可能是无机碘化合物在平流层中的储库物种。

The most parts of thesis as follows:1. Five symmetrical intra-molecular charge transfer oligomeric phenylene vinylene light emitting materials were designed and synthesized using oligomeric phenylene vinylene as a framework.2. The structures of target molecule were characterized by ~1HNMR,~(13)CNMR, IR, MS and element analysis.3. In order to study the influence of the location and numbers of electron-donor and electron-acceptor on their photoelectric performance by changing length of OPV chain, the UV spectra and fluorescence spectra of target compounds has been compared. We have researched into main factors effecting on material emitting red-shift; organic electroluminescence device was prepared using the compound P4. The capability of eletroluminescence was researched.4. The photoelectric properties of P4 was explained by quantum chemical calculation (the Gaussian 98 quantum chemistry program). It is greatly contributed know the whole process of charge transfer to guide the design of red emitters.

本文研究的内容主要包括以下部分：(1)设计并合成5个对称的以齐聚苯乙烯类为骨架的分子内电荷转移型齐聚苯乙烯类发光材料；(2)通过IR，MS，~1H-NMR，~(13)C-NMR和元素分析对所合成的目标化合物进行表征；(3)通过对目标化合物的紫外光谱和荧光光谱比较分析，研究改变OPV的长度，电子给体和电子受体的位置及数量对其光电性能的影响，探讨材料发射红移的主要因素；选取性能良好的目标化合物P4制备成OELD器件，对其电致发光性能进行研究；(4)运用Gaussian98量子化学程序包，采用量子化学方法对目标化合物P4的光电性能从理论加以解释，进一步认识荷移跃迁的整个过程，为红光材料的设计加以指导。

In order to test the theorical results, we designed and carried the experiment to validate it. Then, we found that both chrysin and baicalein cound be directly oxidized by potassium permanganate in acid system.

结果显示我们所建立的QSPR模型在化学发光新物质的发现、化学发光新体系的建立过程中具有一定的理论指导意义。

Two polysiloxanes (SR2 and P67) and one polycarbosilane were chosen as preceramic polymers. TG-DTA-MS, FT-IR, XRD,〓Si MAS-NMR, SEM, TEM, SAD, HREM, chemical analysis and density measurement techniques were used to study the cross-linking and pyrolysis mechanisms of the preceramic polymers. The development of chemical composition and structure, density, phase composition and microstructure of the solid pyrolyzed products during pyrolysis process were systematically investigated. While pyrolysis temperature approached 1000℃, ceramization process of the preceramic polymers almost completed, and ceramic yield of the preceramic polymers hardly changed any more.

选取了两种聚硅氧烷（SR2和P67）和一种聚碳硅烷作为聚合物先驱体，利用TG-DTA-MS、FT-IR、XRD、〓SiMAS-NMR、SEM、TEM、SAD、HREM以及化学成分分析、密度测量等手段，研究了聚合物先驱体的固化机理；以N〓为热解气氛，系统地考察了各种聚合物先驱体在热解过程中，其热解产物的化学成分和结构、密度、相组成及显微结构的演变规律。

This study focuses on students' behavior and attitude related to taking notes in the chemistry study, and the relation between the quality of note and chemistry problem solving.

本研究关注处于化学学习过程中学生的笔记行为和笔记态度，以及其笔记质量与化学问题解决之间的关系。

From it, chemists can drive the shifts of the libraries. In this review, the basic concepts are introduced, the reversible process reported in recent years is reviewed, and the examples and the examples of its applications are given.

介绍了动态组合化学的基本原理，并综述了近年来发现的动态可逆过程和动态组合化学在生物学、新药设计中的应用。

Chemical analysis showed that the fresh basalts and corestones slightly changed in composition except that variations in Fe(superscript 2+) to Fe(superscript 3+) are most noticeable. In the course of corestones changing to saprolite elements of Si, Ca, Na and Mg, the ratio of SiO2/Al2O3 decreased gradually, while the elements of Fe, Al and the values of LOI and CIA significantly increased.

化学全分析结果表明新鲜玄武岩与核心石在除Fe外，其它组分无明显的改变；核心石在转变为腐岩过程中Si、Ca、Na、Mg等元素逐渐流失，Fe、Al等逐渐富集，同时烧失量LOI和化学蚀变指数CIA显著增加，硅铝比逐渐减少。

The compounds may be added to the silver halide emulsion at any time during or after chemical sensitization.The silver halide emulsions utilized in this dioxide may be comprised of any halide distribution,and optimally greater than about 95 mole percent silver chloride.

原则上讲可以在乳剂制备过程中的任何时间加入到卤化银乳剂中，但最好是在化学增感期间或者化学增感之后加入，卤化银乳剂可以由任何卤化物组成，但最好是含AgCl为95％以上的乳剂。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。