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Methods for synthesizing of pinacol are reviewed,the difference of catalytic effects and stereoselectivity with various catalytic systems are introduced in this paper.Highlights are laid on the mechanism and stereoselectivity of new synthetic methods catalyzed by low valent Samarium, Titanium and Trimethyl chlorosilane, etc.

频哪醇合成新进展* The Recent Progress in the Synthesis of Pinacol 李有桂蒋昌盛尤田耙**(中国科学技术大学化学系合肥 230026)本文综述了合成频哪醇的方法，介绍了不同催化体系的催化效果和立体选择性的差异，着重介绍了低价钐、低价钛、三甲基氯硅烷等新的合成频哪醇反应的机理和立体选择性。

Glycyrihizic acid can cause the polarigraphic catalytic wave of oxygen. GA scavenging superoxide ion is demonstrated chemically by the catalytic wave at molecular lever.

本文报道的甘草酸及其皂甙类衍生物存在下的氧极谱催化波，从分子水平研究了GA清除超氧离子自由基〓的化学作用机制，证实清除〓的活性基团是GA分子中与C＝O基共轭的C＝C双键，并非-OH基，纠正了文献观点。

The method comprises heating up the lactic acid solution to gasify at 150-200 degree C, mixing the obtained mixed vapour of lactic acid and water with the carrier gas, entering into gas-solid catalytic reactor to get the reaction product gas by the action of a modified Y zeolite molecular sieve catalytic agent and dewatering after heating up the mixed gas to 200-450 degree C, obtaining the propenoic acid solution through gas-liquid dissociation after cooling the reaction product gas, obtaining coarse propenoic acid products form the propenoic acid solution by gas stripping, azeotropic distillation, extraction and rectification in turns.

其特征在于将乳酸水溶液加热至150～200℃气化得到的乳酸-水混合蒸气与载气混合，将混合后的气体继续加热到200～450℃后进入气-固相催化反应器中经改性Y沸石分子筛催化剂作用脱水得反应产物气体，反应产物气体冷却后经气液分离得到丙烯酸溶液，丙烯酸溶液再依次经过气提、共沸蒸馏或萃取、精馏得到粗丙烯酸产品。

This thesis mainly focuses on overcoming the substrates limition of the present catalytic systems,low catalytic efficiency,and application in total synthesis.1.Conveniently synthesized sulfonamide alcohol titanium complex has been used to catalyze the asymmetric addtition of methyl propiolate to various aromatic and aliphatic aldehydes with high enantioselectivity.

本论文即针对现有催化体系的底物局限性、催化效率低、应用研究少等展开研究：1、我们将简便合成的磺酰胺基醇配体-钛催化体系应用于催化丙炔酸甲酯对各类芳香醛及脂肪醛的不对称加成取得了理想的结果。

In order to further improve the catalytic activity and investigate the influence of catalyst acidic properties on the catalytic activity, acid-treated montmorillonite and molecular sieve Hβwere modified by loading Lewis acid and protonic acid treatment.

为了进一步提高催化剂的催化活性和考察催化剂酸性质对催化剂活性的影响，对酸化蒙脱土和Hβ分子筛进行了改性处理并考察了它们改性后的催化活性。

The catalytic oxidation and catalytic esterification performances of NbFeSAPO-5 catalyst are studied with pyruvic and methanol as raw material.

结果表明：合成的分子筛具有AIPO4-5的骨架结构，并且铁、硅和铌金属杂原子进入了分子筛骨架。

According to studying the factors of using a series of rhodanine ramifications to determine metal ions by catalytic fluorescence method and by utilizing the strong catalysis of metal ions to potassium periodate oxygenating rhodanine, a catalytic fluorescence method of using the new type rhodanine ramifications to determine trace tin, antimony and cobalt was established.

首次研究了系列若丹宁衍生物在催化荧光法测定金属离子中的各影响因素，利用痕量金属离子对高碘酸钾氧化若丹宁具有强烈催化作用的性质，建立了新型若丹宁物质催化荧光法测定痕量锡、锑、钴的新方法。

The results showed that the phosphotungstic had better catalytic activities than the silicotungstic acid. As for the supported HPAs, the silica gel support HPAs' catalytic activities were higher than the activated carbon support HPAs.

实验结果表明：对于非负载型杂多酸催化剂，磷钨杂多酸的催化活性要高于硅钨杂多酸；对于负载型杂多酸催化剂，硅胶负载杂多酸催化剂的催化活性要高于活性炭负载的杂多酸催化剂。

Under the optimum conditions of n: n=40, mass percentage of ZrO2 18%, temperature 400℃, m m=0.02 and reaction time 0.5 h, the conversion was 91.2% and the yield of liquid products was 83.6%. Compared with the results obtained by thermal pyrolysis and catalytic pyrolysis on HZSM-5, ZrO2/Ti-MCM-41 was of better catalytic activity and higher yield of liquid products, and was especially suitable for the pyrolysis of sterically hindered polymers such as PP.

结果表明，n：n=40，ZrO2负载质量分数为18%的ZrO2/Ti-MCM-41，在反应温度400℃，m(ZrO2/Ti-MCM-41)：m=0.02，反应时间30min的条件下，PP的转化率可达91.2%，液体产物的收率为83.6%，该结果优于热裂解及传统的HZSM-5小孔分子筛催化剂的催化裂解结果。

Based on a thorough analysis of the experimental results, a coupling mechanism of the catalytic selective oxidation and non-catalytic partial oxidation in which the surface adsorbed 〓 species and the lattice 〓 species take part synergically.

在全面分析实验结果的基础上，提出了一个由表面吸附氧种〓和晶格氧种〓协同参与的甲烷催化选择氧化与气相非催化部分氧化相耦合的反应机理，催化剂的参与既在表面开辟了生成〓和HCHO的新途径，又可将气相反应中的强氧化型物种转移到催化剂表面，形成有利于选择氧化的表面活性氧种，同时避免了气相中强氧化型物种浓度过高而导致选择氧化产物深度氧化。

The work of this paper is as follows: 1. Looking back the progressing history of the linear motor, introducing the features of the elevator driven by linear induction motor, radicating the topic of this paper "the digital frequency variable control of the elevator bi-side direct driven by linear induction motor". The research of this paper covers the conventional VVVF control, space vector based VVVF control, vector control and DTC.

本文主要开展了以下几个方面的工作： 1 回顾了直线电机发展历史，电机的驱动技术演变，特别是针对直线电机的驱动，简要介绍了直线感应电机驱动电梯的优点和不同结构类型，对传统的v／f控制，基于空间矢量法的v／f控制，矢量控制，和基于电压空间矢量的直接转矩控制进行了比较，确立了本课题的研究主题：直线感应电机双边直推式驱动电梯的全数字变频控制。

The article combines with the treatment of a superficial civil air defense work to introduce how the grouting method to improve the performance of the backfill soil.

文章从治理漂浮人防工事的角度提出了注浆技术在改善回填土性质方面的应用，并详细阐述了注浆技术的施工流程。