查询词典 chiral

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。

Experimental results indicate that the optical purity of the chiral cyanohydrin obtained by enzymatic reaction is quite high, and it is an excellent starting material for the stereoselective synthesis of the chiral amino alcohol compounds.

实验结果表明，醇腈酶催化合成的手性氰醇光学纯度较高，是合成手性氨基醇化合物的优秀原料，并且在随后的化学转化过程中各步反应产物均很好地保留了光学纯度。

In this synthetic system, the central metal coordinated withSchiff base and chiral diol simultaneously, and a "mix-ligands complex" type chiral synthonformed.

在该合成体系中，四价的中心金属同时与氨基酸酯Schiff碱和手性二醇配位，形成了一个"手性合成子"。

Hydrolysis of 2,3-epoxy-butanol-p-methylbenzensulfonate (12) in acidic aqueous media gave chiral vicinal diol (2) in high enantioselectivity (95% ee).2. The chiral vicinal diol s play an important role in organic .

手性邻二醇在有机合成中具有重要的用途，它们是理想的手性合成砌块，可用于合成多种手性药物，许多含有手性邻二醇结构的药物或生物活性物质将有更重要的应用。

In the reaction, by using Michael addition with alkali as protective, utilizing a-alanines N of chiral carbon to introduce N+ lof chiral carbon of the new compound, and making use of the different solubility of resultant in the solvent, disparting form dominical compound.

并利用新生成的手性化合物在反应溶剂中的溶解度差别，分出了以构型为主的产物，克服了脱保护基和拆分条件复杂繁琐问题。

For instance, a chiral or dielectric or conduct circular cylinder, a chiral or dielectric or conduct elliptic cylinder. 5. A general program to calculate any order and any type Mathieu function and its derivation is compiled.

编制了计算任意类、任意阶马丢函数及其导数的程序，此程序解决了多种不稳定性，通用性强，对计算没有任何附加限制，在普通微机上即可保证较高的计算精度和速度。

The scattering by different shape and different media such as dielectric chiral or conduct circular cylider or elliptic cylinder are calculated and RCS curves are maped. The relation between the optimal polarization of the chiral elliptic cylinder and incident angle are maped. In accordance with the map, the information which is useful for radar target identification can be obtained.

对不同形状及参数的导体圆柱、椭圆柱，一般介质圆柱、椭圆柱，旋波媒质椭圆柱的散射特性进行了计算，给出了其RCS的变化曲线，并对极化散射矩阵进行了分析给出了旋波媒质椭柱最优极化的分布图，指出了其可提取用于目标识别的极化信息。

In Chapter 1, the ubiquity of chiral phenomena and its important role in various disciplines, the methods for enantiomer separation, the principles of direct chromatographic separation of enantiomers and the status of chiral CGC are discussed and/or reviewed.

第一章论述或评述了手性特征的普遍性和在众多学科中的重要性、手性分离方法、色谱直接分离手性化合物对映体的基本理论、手性气相色谱研究现状。

This thesis demonstrates the pre-polymers in a polymer-dispersed cholesteric liquid crystals can be polymerized into a polymer film, which can eliminate the aligning capability of the homogeneous alignment layer. Thereafter, the textures of the cholesteric liquid crystals in UV-cured region can be changed from reflective planar texture to the scattered focal conic one. Additionally, the clearing temperature of the liquid crystals can be reduced by doping with chiral dopant or monomers. The cause is the increase of the impurity concentration in LCs. In other words, if the monomers are polymerized, the clearing temperature of LCs in that region should increase due to the decrease of the impurity concentration. Therefore, impurities associated with doping with monomeric and chiral dopants cause the clearing temperature of LCs in cured region to differ from that in uncured region.

本文中，我们提出在高分子聚合物薄膜之胆固醇液晶(polymer-dispersed cholesteric liquid crystals，简称PDCLCs)中，利用紫外光使PDCLC中的单体聚合成薄膜，此即为光引致聚合反应，而该薄膜将原本在表面所作的配向膜覆盖且破坏其配向能力，使胆固醇液晶由原本反射的planar结构转换成散射的focal conic结构；另外，有关液晶材料的相变温度会由於掺杂手性分子或单体而降低，此因液晶材料内『杂质』浓度增加，而造成的液晶材料之不纯度增加，最终导致相变温度降低，若搭配上述光引致聚合反应，则由於光照区之单体聚合，使该区域单体占总材料之比例下降，即不纯度降低，进而使液晶材料之相变温度上升，该区域之相变温度与未照光区有所不同。

Further treatment of the Ru nanoparticles with chiral modifier (1S, 2S)-1, 2-diphenyl-1, 2-ethylene-diamirse (1S, 2S-DPEN and KOH in ionic liquid/i-PrOH mixed solvent resulted in a novel immobilized chiral catalyst which can asymmetrically hydrogenate acetophenone and its derivatives.

将此钌纳米粒子与(1S， 2S)-1，2-二苯基乙二胺（简称(1S， 2S)-DPEN）、KOH在离子液体／异丙醇介质中原位生成一种不对称加氢催化剂，用于催化苯乙酮及其衍生物的不对称加氢反应。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。