天然气与硫酸盐热化学还原反应的模拟实验研究

为探讨天然气中高含量硫化氢形成的化学机制，利用高温高压反应装置，对天然气与固态硫酸钙反应体系进行了热模拟实验研究。使用气相色谱仪、微库仑仪、傅里叶变换红外光谱仪和X射线衍射仪对产物进行了分析，探讨了硫酸盐热化学还原反应的热力学特征，并进行了反应动力学研究。结果表明，高温下天然气与固态硫酸钙可以发生反应，产物主要为硫化氢、二氧化碳、碳酸钙、水和炭。热力学研究表明，天然气与固态硫酸钙的反应可行，升高温度对反应有利，同一温度下长链烷烃与固态硫酸钙发生反应的可能性要比短链烷烃大。根据动力学模型得到反应活化能为96.824kJ/mol。     

硝基苯还原羰化反应制备氨基甲酸酯选择性的研究

在硝基苯还原羰化反应和还原反应的竞争中，使用高分了载体，加人第二金属 组分，升高反应温度有利于还原羰化反应的进行．并且实现了利用双金属效应，在 不含有机配体的体系中高选择性地进行硝基苯还原羰化反应．     

硫酸羟胺与水合肼对B-Z反应的影响

化学振荡与生化、生理现象关系密切，有维生素C参与的化学振荡反应也很引人注目．赵学庄等对维生素C存在的B－Z反应的振荡行为与机理进行了研究．他们的实验表明，当加入维生素C时，B-Z反应的诱导期增长，振荡周期增大，振荡寿命缩短，与向反应体系加入等量的Br-所产生的影响是一致的，并由此推断，维生素C对B－Z反应的影响可能是由维生素C与BrO反应生成Br-抑制了此反应的化学振荡，据此，凡是能与BrO反应生成Br-的物质，其对B－Z反应的影响必将类似于维生素C，硫酸羟胺与水合肼就属于此类物质．本文初步研究了它们对B－Z反应的影…     

Ru催化的C-H键的活化反应

概述了Ru催化的碳氢键的活化反应，包括C-H/烯烃，C-H/炔径和C-H/CO/烯烃 偶联反应，加氢酰化反应，硅化反应。     

NH＋O3→ONH＋O2反应热力学和动力学研究

在量子化学对NH自由基与臭氧O3反应计算的基础上，应用统计热力学方法研究了100～1600 K温度范围内NH和O3反应过程的各热力学量的变化及平衡常数，用经Wigner校正的Eyring过渡态理论计算了不同温度下该反应两不同反应通道的活化热力学量、反应速率常数及频率因子.计算表明，相对于反应通道II，反应通道I不仅有很强的反应自发性，而且在动力学上也是较容易实现的反应.     

聚对苯二甲酸丙二醇酯的甲醇解聚研究

在高压反应器中研究了聚对苯二甲酸丙二醇酯的甲醇解聚反应规律，考察了反应温度、时间等对解聚反应的影响。结果表明，单体收率随反应温度的升高、反应时间的延长而增加；利用凝胶色谱分析了反应后固体产物的组成，利用羧甲基浓度随反应时间的变化建立了动力学方程，计算得到解聚反应的活化能为87.8kJ/mol。     

碳质表面异相还原NO2的反应机理

基于量子化学密度泛函理论（DFT），研究了碳质表面异相还原NO₂的反应机理，针对Zigzag与Armchair两种碳质表面，采用M06-2X方法与6-311G （d）基组联用，优化得到了不同反应路径下所有驻点的几何构型与能量，并对各路径进行了热力学与动力学分析，重点探究了CO在NO₂异相还原反应中的作用规律，同时考察了碳质表面与反应温度对异相反应的影响。计算结果表明，NO₂在碳质表面的异相还原过程主要分为两个阶段，即NO₂还原阶段与碳氧化物释放阶段。通过对比无CO分子参与的反应可知，参与反应的CO分子可以降低各阶段的反应能垒并且加快各阶段的反应速率；CO分子存在时，NO₂还原阶段的反应能垒被降低，促进了NO₂还原成NO的异相反应过程，同时参与反应的CO分子与碳质表面剩余氧原子结合，形成CO₂分子并释放，使碳氧化物释放阶段的反应能垒降低，从而促进了整体还原反应的进行。此外，与Armchair型相比，基于Zigzag型碳质表面的NO₂异相还原反应能垒更低且反应速率更快，说明NO₂异相还原反应更容易在Zigzag型碳质表面进行。最后，由反应动力学分析可知，随着温度上升，各阶段的反应速率均增大，说明提高温度对碳质表面的NO₂异相还原能够起到促进作用。     

改进的Ugi法合成胺烷基二茂铁衍生物的反应研究

在改进的Ugi法会成胺烷基二茂铁衍生物的反应中，研究了反应的投料比、反应底物、反应温域等因素对反应的影响，并对反应机理进行了探讨。     

微波辅助聚合物支载的有机反应

微波辐射下，聚合物支载的有机反应易于进行，操作简便，反应速率高，反应 时间短，产率高，纯度好，聚合物载体稳定，综述了微波辅助不溶性聚合物和可溶 性聚合物支载的有机反应。     

二氯卡宾与甲醇及甲硫醇插入与氢抽提反应的量子化学计算

利用密度泛函和自然键轨道理论及电子密度拓扑分析方法，对单、三重态CCl2与CH3MH（M=O，S）中C—H和M—H键的插入反应及抽提氢反应进行了研究．在B3LYP／6-311G（d，p）水平上优化了势能面上构型，并以频率分析和内禀反应坐标法进行了确认．计算了各物种的CCSD（T）／6-211G（d，p）能量．结果表明，主反应通道主要发生在单重态势能面中，单重态CCl2既可以与C-H及M—H键发生插入反应，存在四条主反应通道，分别生成P1[CH3OCHCl2，反应Ⅰ（1）]，P3[Cl2HCCH2OH，反应Ⅰ（2）]和PS[CH3SCHCl2，反应Ⅱ（1）]，P7[Cl2HCCH2SH，反应Ⅱ（2）]，也可以与CH3MH发生抽提氢反应，分别生成P4[CH2O＋CH2Cl2，反应Ⅰ（3）]和P8[CH2S＋CH2Cl2，反应Ⅱ（3）]．同时，存在三重态CCl2与CH3SH插入生成^3P4[CH3SCHCl＋Cl]的反应通道．进一步对反应通道上的关键点进行了自然键轨道和电子密度拓扑分析．     

Contributions to the Chemistry of the Binary Compounds of the Transition Elements

Phase and structural relationships of the sulfur, selenium, and tellurium compounds of the 4d and 5d transition elements of groups IV to VII of the periodic system are discussed. Homologous elements behave very similarly with respect to the chalcogens, and this is particularly the case for niobium and tantalum, and for molybdenum and tungsten. However, zirconium, niobium, and molybdenum have a greater tendency towards formation of chalcogen-poor phases than their homologues hafnium, tantalum, and tungsten. Subchalcogenides are known only for zirconium and niobium. The number of phases and the tendency towards formation of solid solutions are considerably smaller among the tellurides than among the sulfides and selenides. The crystal structures of the telluride phases also differ from those of the sulfide and selenide phases of analogous composition. In addition, a review of the phase and structural relationships of the arsenic and antimony compounds of the 4d and 5d transition elements of groups V to VII is given.     

纳米粒子的精准组装

纳米材料由于其独特的光、电、磁、力学等性质,成为了构建功能材料与器件的理想基元。实现纳米粒子的精确组装,是探究粒子之间的耦合聚集性质和制备宏观功能器件的基础。但是由于纳米粒子的小尺寸以及在溶液中运动的随机性与复杂性,精准控制纳米粒子组装体的形貌以及在空间中的相对位置仍存在巨大挑战。为了将纳米粒子组装成理想的有序结构,许多控制粒子组装的策略与方法得到发展。本文首先概述了纳米粒子自组装的控制方法与典型形貌,着重分析了影响粒子精准排布的因素与控制方法,并对纳米粒子及其组装体的光学性质与器件应用的最新研究进展进行了讨论,最后对目前纳米粒子精准组装所面临的挑战以及未来发展的方向进行了展望。     

电流变液中悬浮颗粒的体积与形状的变化

基于偶极近似,运用电极化方法,定量研究了电流变液中悬浮颗粒在外电场作用下其体积和形状的变化,并计算了其体积和形状的相对变化率.研究结果表明:悬浮颗粒的体积和形状的相对变化率均与电场强度的平方成正比,并与ER本身的性质有关.一般情况下,颗粒的体积和形状的相对变化率分别为8.4%和12.5%,对总体积变化率的贡献为1.68%.这种变化对于ER系统的电涨和电热都作出了贡献,仅当将颗粒当作刚性球时,其自由能才与电场强度的平方成正比.     

LOW DENSITY POLYETHYLENE/CLAY NANOCOMPOSITES MODIFIED BY ETHYLENE COPOLYMERS： EFFECTS OF FUNCTIONALIZED SEGMENTS ON MORPHOLOGY

Melt extrusion was used to prepare binary nanocomposites of ethylene copolymers and organoclay and trinary nanocomposites of low-density polyethylene （LDPE）, ethylene copolymer and organoclay. X-ray diffraction （XRD） and transmission electron microscopy （TEM） were used to analyze the structure of the clay phase and the morphology of the nanocomposites. Influences of the comonomer in the copolymer and the content of the copolymer on the morphology of the resulting nanocomposites were discussed. The binary and the trinary composites may form intercalated or exfoliated structures depending on the interaction between the copolymer and the clay layers and the content of the copolymer.     

Phenolic potential of Tannat, Cabernet-Sauvignon and Merlot grapes and their correspondence with wine composition

The phenolic potential of Tannat, Cabernet-Sauvignon and Merlot grapes was evaluated in 2001 and 2002 and its correspondence with the colour and composition of the respective wines was established. Three vineyards of each variety, situated in the south of Uruguay were considered. Two samples of each vineyard were taken at the moment of the harvest. Phenolic richness, extractable anthocyanins contents and total potential in anthocyanins of the grapes were estimated. Two fermentations on skins were carried out for each vineyard using 50 kg of grape in each one. The anthocyanic and total polyphenols contents of the musts were analysed every 24 h, and skins extractions were carried out in parallel in the laboratory. The duration of the maceration for each variety was decided in function of the analytical results in the grapes, musts and skins extractions. Wines were analysed 2 months after the alcoholic fermentation, determining its phenolic composition and colour. Tannat grapes presented anthocyanic and total polyphenols contents significantly higher in both years. Therefore, wines from this variety presented colour intensity and phenolic contents statistically higher than Cabernet-Sauvignon and Merlot. The correlations between the phenolic contents of the grapes, skins, musts and wines were very significant. Colour intensity and phenolic contents of the wines were highly correlated with the total polyphenols of the grapes and with anthocyanins of the grapes, skins, musts and wines. The estimate of the phenolic potential of the grapes and the extractability of the pigments allows to manage more adequately the fermentation on skins and is an interesting tool to predict the colour and the composition of the wines.     

PROPERTIES AND MORPHOLOGY OF UNSATURATED POLYESTER/ACRYLATE-TERMINATED POLYURETHANE/ORGANOMONTMORILLONITE NANOCOMPOSITES

Unsaturated polyester resin （UPR）/acrylate-terminated polyurethane （ATPU）/organo-modified montmorillonite （OMMT） nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene （S） and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82：15：3, the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy.     

Applications of Thermal Analysis and Coupled Techniques in Pharmaceutical Industry

Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. The robustness and sensitivity of instrumentation, the introduction of automation and of reliable software according to the industrial needs widened considerably the areas of applications in the last decade. Calibration of instruments and validation of results follow the state of the art of cGMP as for other analytical techniques. Thermal analysis techniques are especially useful for the study of the behavior of the poly-phasic systems drug substances and excipients and find a unique place for new delivery systems. Since change of temperature and moisture occur by processing and storage, changes of the solid state may have a considerable effect on activity, toxicity and stability of compounds. Current requirements of the International Conference of Harmonisation for the characterization and the quantitation of polymorphism in new entities re-enforce the position of thermal analysis techniques. This challenging task needs the use of complementary methods. Combined techniques and microcalorimetry demonstrate their advantages. This article reviews the current use of thermal analysis and combined techniques in research and development and in production. The advantage of commercially coupled techniques to thermogravimetry is emphasized with some examples. This revised version was published online in August 2006 with corrections to the Cover Date.     

3,7-二硝基亚氨基-2,4-二氮杂双环[3,3,0]辛烷的放热分解反应动力学

The kinetic parameters of the exothermic decomposition reaction of the title compound in a temperature-programmed mode have been studied by means of DSC. The DSC data obtained are fitted to the integral, differential and exothermic rate equations by linear least-squares, iterative, combined dichotomous and least-squares methods, respectively. After establishing the most probable general expression of differential and integral mechanism functions by the logical choice method, the corresponding values of the apparent activation energy (Ea), pre-exponential factor (A) and reaction order (n) will be obtained by the exothermic rate equation. The results show that the empirical kinetic model function in differential form and the values of Ea and A of this reaction are (1-α)0.44, 230.4 kJ/mol and 1018.16 s-1, respectively. With the help of the heating rate and obtained kinelic parameters, the kinetic equation of the exothermic decomposition reaction process of the title compound is proposed. The critical temperature of thermal explosion of the compound is 302.6℃. The above-mentioned kinetic parameters are quite useful for analyzing and evaluating the stability and thermal change rule of the title compound.     

多弧离子镀TiN与不同金属基材间的接触界面与表面特性

用多弧离子镀技术在不同金属基材上进行TiN镀膜实验,制备了TiN/Fe、 TiN/Cu和TiN/Cr/Cu复合膜.借助扫描电子显微镜(SEM)、 X射线衍射仪(XRD)和光电子能谱(XPS),研究了TiN与Fe、 Cu和Cr/Cu三种不同衬底接触界面的形貌、结构及其表面特性.SEM观察发现,在一定离子镀膜条件下, TiN涂层可与Fe、 Cu和Cr/Cu金属基材形成均匀平整的接触界面,在铜基上TiN界面清晰,在Fe与Cr/Cu界面有明显的层状晶界微结晶分布.XRD分析显示, Fe、 Cu和Cr/Cu表面生成的薄膜都包含TiN、 Ti2N等多晶相,在Cr/Cu界面还包含Ti-Cr的金属间化合物.XPS结果表明,表面除了TiN膜外,还生成TiO2和TiOxNy等氧化膜.Ar+刻蚀5 min后, TiO2消失, TiOxNy减少, TiN则呈增加趋势.TiN与Cr/Cu界面形成明显的Ti-Cr和Cr-Ni互扩散层,这有助于增强薄膜附着力,形成较牢固的TiN涂层.