查询词典 chiral

During the total preparation process, it was inevitable to conduct with the chiral center of prolinamide and the target product would became racemized or even could not be obtained at all.

由于在合成过程中，不可避免的触及不对称中心，发生消旋使产率下降甚至得不到产物，因此本文还研究了D-脯氨酰胺在不同温度、pH值、反应时间下对它的消旋的影响和脱羧机理，这对以后的工业化生产有着极其重要的意义。

Some economic and practical polysaccharide-based chiral stationary phases for HPLC were prepared and applied to the enantiomeric resolution of a variety of racemates.

本论文选择高效液相色谱手性分离为研究目标，制备了一些经济、实用的多糖类手性固定相，并对多种手性化合物的拆分进行了研究。

Many studies dealing with chiral drugs which are administered as their racemates rely on non-stereoselective analytical techniques. It was shown that the use of such an analytical method can lead to the collection of data which may be both quantitatively and qualitatively inaccurate with respect to the individual enantiomers.

一般非对掌选择性的药物分析条件，得到的药物血中浓度是个别镜像异构物的总和，而非个别镜像异构物的血中浓度，因此并无法对於对掌性药品的立体选择性动态学做定性或定量的探讨。

Some compounds possessing chiral center themselves may be racemates and appear racemic phenomenon in the extraction and separation from medicine herbs, structure modification and chemical synthesis.

但是，由于含有手性中心的中药有效成分本身可能是消旋体、或者在分离提取、结构改造及化学合成时会出现外消旋化现象，使新药研制与开发中面临对映体成分的分离制备、体内手性药物分析及对映体特异性药代动力学研究等重大难题。

Direct enantiomeric separation of racemic mixtures of 13 β-amino alcohols and β-hydroxy sulfides was achieved by HPLC using Chiralcel OD, Chiralcel OJ and Chiralpak AD as chiral stationary phases and hexane/2-propanol mixture as eluent. These racemates were completely separated into enantiomers at least on one of these stationary phases.

在以正己烷-异丙醇为移动相的体系中，用ChiralcelOD，ChiralcelOJ及ChiralpakAD作为手性固定相对13种β-氨基醇及β-羟基硫醚类化合物对映体进行HPLC手性拆分，这些化合物至少能在一支柱上得到基线级分离。

Chlorpheniramine, promethazine. dioxopromethazine and ofloxacin racemates were separated with high performance capillary electrophoresis using β-cyclodextrin or its deriva- tives as chiral selectors.

1引言在1985年首次应用于手性分离'后，高效毛细管电泳就以其高柱效，高分辨和分析时间短等优点而被迅速用于各种手性化合物的拆分。

Total of 11545 chiral crystals were identified by the polarizers.

使用偏光显微镜鉴定了11545颗晶体的手性。

The role of pions in nuclear physics is associated intimately with chiral symmetry, and has evolved far since the initial ideas of Yukawa in which the pion was the intermediate particle of the nuclear forces.

介子在核物理中的作用直接联系着手征对称性，汤川秀树关于π介子的最初概念已经大大发展了。

Generally the catalysts have high activity and good selectivity. At present the coupling reactions of organoborahes with terminal olefins s acid chlorides and aryl halides play an important synthetic approaches in organoborane chemical. The catalysts can be used by many kinds of organometal compounds such as: irons cobalt nickel ruthenium rhodium palladiums titaniums zirconiums tins indium and lithium organic compounds; The achievement has been amazed in preparing of unsaturated or saturated compounds and in synthesizing of natural products bioactive molecules and chiral compounds.

目前，卤代烃与不饱和烃的偶联反应和有机硼试剂与酰卤和卤代烃的偶联反应已成为有机合成的研究热点，此类反应可用铁、钴、镍、钌、铑、钛、锆、锡、铟、锂等多种有机金属化合物来催化，用于形成含饱和或不饱和C-C键的化合物，并已在天然产物、液晶、具有生理活性物质和手性化合物的合成中应用。

Chapter two is concerned with the syntheses and characterization of some chiral ligands and consists of relevant mechanism of reaction( for example, N anion acts as nucleophilic reagent and different nitriles act as reacting substance).

第二章讨论了若干手性配体的合成与结构，并包含了相关反应的机理探讨(例如N~-做为亲核试剂、不同的腈作为反应底物)。

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。