查询词典 catalysis

Then the cyclocarbonylation of propargylic alcohols under the catalysis of Pd 〓 with CuBr〓 and BQ was studied. Due to the high activity the yields of -α-bromoalkylidene-β-lactones were lower than that of -α-chloroalkylidene-β-lactones while the coupling reaction of -α-bromoalkylidene-β-1actones (i. e. Sonogashira and Suzuki coupling reaction) was quite smooth to afford the products in high yields.

接着我们研究了炔丙醇在Pd〓-CuBr〓-BQ催化体系下的羰基插入环化反应，由于-α-溴代亚烷基-β-内酯环化合物的活性高于-α-氯代亚烷基-β-内酯环化合物，导致反应收率偏低，而同样基于此原因，-α-溴代亚烷基-β-内酯环化合物的偶联反应进行得很顺利，而且收率很高。

Some aqueous catalysis systems have been applied in the industrial production of butyl aldehyde by propene hydroformylation.

其中水溶性催化剂体系已经用于丙烯氢甲酰化反应制备丁醛的工业化生产，然而，长链烯烃在含有催化剂的水相中溶解性较差，反应速率较慢。

Beside the catalysis in transferring the high energy phosphate bond from ATP to NDP, NDPKs also show the activities of NDP kinase and proteinic phosphotransferase.

该酶除了催化腺苷三磷酸和核苷二磷酸之间高能磷酸基团的转移外，还具有NDP激酶活性和蛋白磷酸转移酶活性，并参与转录调控和信号转导。

The introduction of cheap protonic acids can accelerate the formation of an active enanmine intermediate and stabilize the transition state by hydrogen bonding. Consequently, catalytic activity and enantioselectivity of the catalysis system are remarkably increased.

价廉易得的质子酸的引入不仅可促进活性中间体烯胺的生成，并可通过形成的氢键稳定反应的过渡态，从而显著提高该催化体系的催化活性和立体选择性。

Transition metal Pyrazolyl ligands have attracted considerable attention as in catalysis, magnetic coupling, biological mimicry, electron transfer, optic-physics area because of pyrazolyl ligands have luxuriant self-assembly chemistry and as a kind of multifunctional organic ligand.

吡唑类配体是一种较复杂的多功能有机配体，有着丰富的自组装化学，使其形成的过渡金属配合物在催化、生物仿生、磁学耦合、电子转移和光物理性质等方面具有潜在的应用价值，近年来受到广泛的关注。

For the first time we synthesized nanoscale metal hydrides of lanthanum, neodymium, samarium, dysprosium, and ytterbium with high efficiency under mild condition by complexometric catalysis instead of traditional preparation at high temperature and high pressure. It is for the first time that we synthesized lanthanide organic compounds with catalysts or initiating agents at atmosphere and ambient temperature,and some of them are new compounds. Nanometric lanthanide metal powders are prepared by thermal decomposition of the compounds in vacuum. Differently from the traditional method, size of the products prepared by our method is less than 40nm, and the activity of the reaction is very high. They are pyrophoric at atmosphere. They can make some reactions without activity or low activity show extremely high activity .We investigated influent regulations of methods, conditions to scale and special surface.

我们首次成功地用络合催化等方法取代需在高温高压下进行的传统方法，在温和条件下高效率地合成出纳米尺寸镧、钕、钐、镝、镱的金属氢化物；首次在常压常温的条件下，通过催化、引发等方法合成镧系金属有机化合物，再将其真空热分解成功地制备了纳米尺寸的镧、钕、钐、镝、镱等金属粉末；与传统方法不同，这些方法得到的产品基本颗粒尺寸小于 40 nm，遇到空气燃烧，具有极高的化学反应活性，使原来活性很低甚至观察不到活性的反应大幅度提高反应速率和产率；考察了制备方法、制备条件等因素对晶粒尺寸、比表面积大小等的影响规律。

Resolution of racemic drugs by lipase catalysis offers an excellent technology for the preparation of single-isomer chiral drugs in organic solvent.

在有机相中，脂肪酶催化消旋体的拆分，为制备单异构体手性药物提供了重要的技术手段。

Catalysis of thecomplex mental oxides can be greatly effected by it's redox property. In the present work, a significant study on the oxidation performance and re-oxidationperformance of Mo-V-Te-Nb-O catalyst was carried out using a pulse reactor in which theoxidation of propane and the reoxidation of catalyst were taken place alternatively.

我们利用脉冲反应器，催化剂预氧化与丙烷氧化反应轮流进行，重点考察了反应条件下Mo-V-Te-Nb-O催化剂氧化丙烷的性能及其再氧化性能，并对催化剂的结构进行了表征。

To broaden desert shrub new utilizing fields, accelerate desert shrub developing to the direction of high added-value and high benefit, the paper studied on the liquefaction of Salix, Caragana and Poplar in the presence of Phenol under sulfuric acid catalysis. The optimum processing parameters for Salix, Caragana and Poplar liquefaction and resinification were investigated. The effect of molar ratio of formaldehyde to liquefied products and NaOH to liquefied products on the character and glue strength of liquefied products resin was studied.

摘 要：为了开辟沙生灌木资源新的应用领域，促使沙生灌木资源的利用向高附加值、高效益的方向发展，本文以苯酚作液化剂，以稀硫酸作催化剂对沙柳、柠条和杨木进行液化实验，分析了反应温度、液比、催化剂用量及液化时间对液化反应的影响；并研究了沙柳、柠条和杨木液化产物树脂化合成工艺和配方，分析了不同的甲醛与液化产物摩尔比以及氢氧化钠与液化产物摩尔比对沙柳、柠条和杨木液化产物树脂的各项性能的影响。

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。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。