非弹性体增韧—聚合物增韧的新途径

本文是一篇关于非弹性增韧方法的综述。文章首先简要回顾了传统的橡胶增韧韧性聚合物材料的机理,然后着重介绍了最近在国外出现的刚性有机填料(ROF)增韧的基本概念、分析方法和增韧的冷拉机理,列举了脆性塑料粒子和韧性基体组成的合金体系的大量实验结果来说明以上内容,最后通过与传统橡胶增韧机理的对比指出非弹性体增韧是不同于后者的一种新增韧方法,并有可能成为制备高强度、高韧性工程塑料的一种新途径。     

联二脲氧化生成偶氮二甲酰胺反应的钒催化机理

在钒催伦剂存在下，用氯酸钠氧化联二脲制成偶氮二甲酰胺，从钒催化剂的单晶培养和结构解析入手，通过反应动力学研究，用ＥＳＲ检测反应过程中四价钒的生成，用分光光度法（分别以钛钛试剂和硫氰酸铵为显色剂）确定了反应过程中三价钒的生成和变化情况，从而提出了可能的催化机理，还利用量化计算从热力学角度证实了所提出的包括四价钒铬离子歧化过程在内的钒催化机理的合理性。     

苯与丙烯烷基化失活沸石催化剂氢再生机理

对工业中试用于苯与丙烯烷基化失活β－沸石改性催化剂进行了H2再生研究。通过对失活、新鲜和再生后催化剂的TPO、TPD、孔结构测定和活性评价以及失活和再生催化剂样品上炭组成的GC－MS分析，讨论了H2再生后催化剂催化性能的恢复状况。解释了虽然仍有部分炭未被除去，但酸性和活性恢复良好的原因。提出了本文体系失活催化剂H2再生过程的作用机理。     

ZnO超微粒子光催化氧化降解n-C7H16的研究

利用ZnO光催化氧化技术对气相n-C7H16进行了降解研究，考察了氧气、水燕气体积分数等因素对n-C7H16光催化氧化的影响，利用气相色谱－质谱联用仪和气相色谱仪对气相光催化反应过程中的气体组成进行了定性分析，并对主要中间产物丙醛进行了定量分析，结果发现，ZnO超微粒子光催化氧化n-C7H16的降解率较高，n-C7H16绝大部分被完全氧化成CO2，探讨了n-C7H16光催化氧化反尖的动力学行为及机理。     

芳基汞化合物的性质研究——Ⅶ.邻位取代苯基氯化汞的质子分解反应

本文研究了邻位取代苯基氯化汞o-XC_6H_4HgCl(X=CH_3、H、Cl、Br、COOC_2H_5、NO_2)与HCl(NaI)在85％对氧陆圜水溶液中的质子分解反应,证明反应按S_El历程进行。视取代基不同,反应速度次序如下:CH_3>H>Cl>COOC_2H_5～Br>NO_2。从化学反应与紫外光谱的研究以及理论计算结果表明,p或π电子的邻位取代基对水原子有分子内配位,它对反应速度有重要影响。测定了15种p-、m-、o-取代苯基氯化汞在80％对氧陆圜水溶液中在40.0℃的质子分解反应的速度常数k_1,表明给电性取代基加速反应,吸电性取代基使反应减慢,这可以看作是反应中心在芳环上的芳基汞化合物的S_E1反应所具有的一个特点。     

甲烷—空气燃烧中NOx生成的简化模型研究

用特征值－特征向量法对甲烷－空气燃烧时ＮＯＸ生成的化学反应机理进行了简化，得到了仅由１５个基元以应组成的简化反应模型。对比计算结果表明，该模型能在较宽燃空比内与全面模型很好吻合，因而可望用于燃烧过程数值模拟时对ＮＯＸ生成的预测     

反相微乳液法制备纳米Al2O3颗粒及其形成反应机理的研究

通过聚乙二醇辛基苯基醚(曲拉通X-100)/正丁醇/环己烷/水溶液形成的体系, 采用反相微乳液法合成了Al₂O₃纳米粒子. 对前驱体进行热分析(TG-DTG-DTA), 确定了合适的煅烧温度为1150 ℃. 采用X射线衍射(XRD)、透射电镜(TEM)、紫外可见分光光度法(UV-vis)分别对产物的结构、粒度和形貌进行了表征, 考察了微乳液中水与表面活性剂的物质的量之比(ω_o)、煅烧温度和煅烧时升温速率等关键因素对产物形貌和晶相的影响, 并通过分析进一步揭示了Al₂O₃纳米粒子的形成机理. 结果表明, 控制ω_o为10、煅烧温度为1150 ℃可得到分散性好、粒径分布均匀的Al₂O₃纳米粒子, 且2 ℃/min的升温速率更有利于产物向稳定的α晶相转变.     

An unusual new reaction of α-olefins with magnesiumn-alkyl derivatives catalyzed by Cp2ZrCl2

The reaction of organomagnesium compounds (OMC) containing alkyl radicals of normal structure with -olefins, resulting in the formation of alkenylorganomagnesium compounds and accompanied by hydride transfer was discovered and systematically investigated. A scheme providing for the formation of zirconacyclopentane complexes was proposed for the mechanism of the reaction.Institute of Organic Chemistry, Ural Branch, Russian Academy of Sciences, 450054 Ufa. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1187–1196, May, 1992.     

Elucidation of the Role of the Complex in Hydride Transfer Reaction between Methylene Blue and 1-Benzyl-1,4-dihydronictinamide by Effect of γ-Cyclodextrin

The kinetics of the hydride transfer reaction between Methylene Blue (MB⁺) and 1-benzyl-1,4-dihydronicotinamide (BNAH) were studied in 10% ethanol-90% water mixed solvents containing β- and γ-cyclodextrins (β-CD and γ-CD). The pseudo-first order rate constant shows kinetic saturation at high initial concentration of BNAH. This indicates the formation of a complex between MB⁺ and BNAH. The reaction was suppressed by addition of β-CD, but enhanced by addition of γ-CD. MB⁺ and BNAH were separately accommodated within the β-CD cavity and the cavity walls may protect the activity site of the reactants. On the other hand, in the MB⁺-BNAH-γ-CD system, the inclusion of the complex between MB⁺ and BNAH with γ-CD occurred. This effect of γ-CD can distinguish between the productive and non-productive nature of the complex.     

机械球磨与反应烧结合成Sr2CeO4发光体的研究

Sr₂CeO₄ phosphor was synthesized by mechanical milling and reactive sintering in this work. The solid state reaction of SrCO₃and CeO₂ (2∶1) started at about 850 ℃ and completed at 1 000 ℃ for about 4 h. Two types of formation mechanism of Sr₂CeO₄ were proposed. When the starting powder mixture was fired above 1 000 ℃, the unstable intermediate phase SrCeO₃was developed, which then reacted with SrCO₃to form the final product Sr₂CeO₄, however, SrCO₃and CeO₂ converted directly to Sr₂CeO₄ at a lower temperature. The XRD results showed the crystal structure of Sr₂CeO₄ was orthorhombic. The emission spectra displayed a broad band with maximum at about 465 nm. The mechanical milling of starting power mixture and the sintering temperature had no effect on this emission spectra.