选择性

As well as activity was exhibited. Theaddition of cinchonidine led to a remarkable increase in the reaction rate, as confirmed bythe IR study that the modifier activates the carbonyl groups of the reactant through itsquinuclidine nitrogen. On the contrary,〓 exerted a strong inhibition effect on theenantioselective hydrogenation. Chapter 3 Finely dispersed polyvinylpyrrolidone-stabilized iridium andbimetallic clusters were prepared by the alcohol-water reduction method.

第三章 采用醇水还原的方法制备了聚乙烯基吡咯烷酮稳定的铱纳米簇及双金属纳米簇，对丙酮酸甲酯的催化氢化表明，在铱金属簇催化体系中，辛可尼定不仅诱导了一定的对映选择性，同时对反应活性有明显的促进作用，平均反应速率可提高2-6倍。

A new cinchonine ion selective electrode was prepared by dipping the Ag/AgCl electrode into the sol-gel solution for more than 3 times, and then standing for 48h at room temperature, and finally activating for at least 12h in a 1.0×10^(-2)molL^(-1) cinchonine solution.

将Ag/AgCl电极于溶胶－凝胶溶液中反复浸3次以上，在室温静置48h后在1.0×10^(-2)molL^(-1)，辛可宁溶液中活化至少12h即制成新型的辛可宁选择性电极。

It is demonstrated that the chiral quaternary ammonium salts catalysts exhibit promising catalytic properties for the substrate. Part III: The synthesis and the characterizing of the macroporous aminomethyl resin-supported cinchona alkaloid complexes and the study on its catalytic properties The part consists of two subsections. the macroporous aminomethyl resin -supported cinchona alkaloid complexes were synthesized by the stuff (cinchonine, quinine and macroporous aminomethyl resin). Their structures were characterized by means of elemental analysis, XPS, TG/DTA; the chiral polymer-supported complexes were first used as catalysts for the reduction of ketones. Their catalytic properties for the reduction processes were investigated. The comparison of the products e.e., the conversion of the substrate among different reduction processes was employed with determined by HPLC. The effects of the time, the temperature, the ratio of catalyst to substrate, reaction solvent as well as the recycle times were also discussed.

第三章聚-4-氨甲基苯乙烯负载金鸡纳碱金属络合物的合成与表征及其不对称催化性能研究本章分为两节，以辛可宁和奎宁及聚-4-氨甲基苯乙烯为原料，合成了4种聚-4-氨甲基苯乙烯负载金鸡纳碱络合物催化剂，并对它们的结构用元素分析、X-射线光电子能谱、TG/DTA等几种测试手段进行了表征；首次将所合成的手性高分子负载的金属络合物用于催化芳香酮不对称还原反应，详细研究了所得的手性高分子负载的金属络合物对不同底物的催化性能，用HPLC等分析手段定量检测了还原过程的底物转化率及其产物对映异构体选择性，并考察了反应时间、反应温度、催化剂和底物投料比、反应溶剂和循环次数对催化性能的影响。

The investigation of the catalytic activity and stereoselectivity of ligand 10 was also carried out under another standard set of K〓Fe 〓 conditions (〓/ligand/substrate=0.002: 0.01: 1). The AD reaction of seven olefins gave corresponding diols in 72～99% yield (except for ethyl cinnamate, 48%) and 91～99% ees, which was comparable to those obtained from the reactions using the commercial ligand 〓PHAL.

将单季铵盐手性配体10用于AD反应的另一个催化体系〓BuOH-H〓O/K〓Fe〓中考察其催化活性和立体选择性，在七种烯烃的AD反应中，〓、配体与底物的摩尔比为0.002：0.01：1时，化学产率为72～99％（肉桂酸乙酯除外，为48％），ee值为91～99.9％，与商品配体〓PHAL的催化结果相当。

MIP and NIP have very good selective adsorption abilities to both 1 -hydroxy -2 - naphthoic acid and citrinin molecules.

结果表明MIP和NIP对1-羟基-2-萘甲酸和桔青霉素分子都有着很好的吸附选择性。

Clear-cutting is favored by the timber industry over the alternative, selective cutting of individual trees in a forest, for several reasons.

相比在一片森林中有选择性的砍伐树木，伐木公司更偏爱皆伐，有几方面的原因。

In our experiments, we don not found the considerable selectivity of cleavage at the certain bases.

并且在我们实验中，没有发现〓对特定基团的选择性破坏。

Close-minded individuals opted for information that went along with their views 75 percent of the time.

思想保守者尤甚。他们75%的时候都选择性地只看相似观点。

Because this non-template method is based on the selective transfer of a single layer of close-packed microspheres from the colloidal crystal film to the PDMS stamp surface, it is possible to realize fine control over the microstructures of colloidal crystal film using a layer-by-layer lift-up process.

这一方法摈弃了传统的模板技术，采用PDMS为印章，在每个揭起过程中选择性地把一个单层的紧密堆积的微球从胶体晶体膜层揭走，通过layer-by-layer的揭起过程，实现了对胶体晶体膜的微观结构的精确控制。

Methods: Selective renal artery embolization was performed in 68 patients via femoral artery with Seldinger technique, 30 cases were embolized with gelatin sponge chips before operation for renal carcinoma, and 8 cases were embolized with MMC and iodized oil, and gelatin sponge for palliative treatment of advanced renal carcinoma, 6 cases were embolized with thread segments for symptomatic renal angiomyolipoma, 24 cases were embolized with self blood coagulum, gelatin sponge and/or steel coils for traumatic renal hemorrhage.

采用改良Seldinger技术经皮股动脉穿刺插管，对68例进行选择性肾动脉栓塞治疗，其中30例为肾癌术前辅助治疗，应用明胶海绵颗粒栓塞；8例为晚期肾癌姑息性治疗，采用丝裂霉素＋碘油的乳剂行末梢栓塞，然后用明胶海绵行肾动脉主干栓塞；6例症状性肾血管平滑肌脂肪瘤，采用真丝线段栓塞；24例肾创伤出血，采用自身血块、明胶海绵或弹簧钢圈栓塞。

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。