查询词典 chiral

The chiral metal complexes are mainly used on the chiral catalytic reaction as catalyzer. In recent years,some high activity chiral catalysts brought more and more people\'s attention.

手性金属配合物的主要用途是作为催化剂在手性催化反应中应用，近年来一些高活性手性催化剂的开发应用越来越引起人们的重视。

Second, proceeding with the fact thatthe constructing vector wave functions of conventional circular cylindrical and sphericalvector wave functions are linear independent solutions to the electromagnetic field waveequations in biisotropic medium,spectral impedance boundary conditions are proposed forinfinitely long perfectly conducting circular cylinder and sphere coated with biisotropic media,respectively,which generalize the applicable range of planar structures and are suitable toanalyze the electromagnetic problems involving their counterpart structures.

所用的方法是在Fourier变换谱域中的一阶线性微分方程组理论和矩阵技术，提出了适用于Chiral媒质半空间辐射问题的耦合镜像原理(即镜像电流的振幅和相位是由Chiral媒质中的本征左、右旋圆极化波相互耦合来确定的)和适用于研究平面分层Chiral媒质电磁问题的一般性更高的分析方法。

Chiral ligand-exchange chromatography is one of the basic chromatography method for enantiomer separation, in which chiral ligands and metal ions are two essential elements to determine the chiral selectivity.

手性配体交换色谱法是分离手性化合物的基本方法之一，其中手性配体和金属离子是决定手性化合物分离选择性的根本因素。

In the chiral SU(3) quark model, we use the coupling between quarks and nonet scalar meson fields and nonet pseudo-scalar meson fields to describe the medium and long range interactions, and use one gluon exchange to describe the short range interaction. In the extended chiral SU(3) quark model, besides the nonet pseudo-scalar meson fields and the nonet scalar meson fields, the coupling between vector meson fields and quarks is also considered, the short range interaction can be dominately described by vector meson exchange. We investigate the nucleon-hyperon interaction in the extended chiral SU(3) quark model and study the S-wave phase shifts of N-Λ and N-Σ systems. Comparing to the results in chiral SU(3) quark model, we find that the short-range interaction could be described either by the one-gluon exchange or vector meson exchange.

在手征SU(3)夸克模型中，用夸克与标量介子九重态和赝标介子九重态场的耦合来描述中长程相互作用，单胶子交换来描述短程相互作用，推广的手征SU(3)夸克模型是在原来手征SU(3)夸克模型的基础上进一步引入了夸克和矢量介子九重态场的耦合，主要由矢量介子交换来描述短程相互作用，在推广手征SU(3)夸克模型下研究了核子－超子相互作用过程，计算了N-Λ和N-Σ相互作用的S波散射相移，通过和手征SU(3)夸克模型的结果比较，发现N-Λ和N-Σ系统的短程相互作用既可以由单胶子交换来描述，也可以由矢量介子交换来描述。

By using on-lined pyrolyzer-chiral MDGC/NPD,it was found that,racemization of S--nicotine reagent was highly synchronous to its thermal degradation process.

采用在线裂解-chiral-MDGC/NPD，发现S-尼古丁试剂的消旋化与热裂解进程具有高度的同步性。

Yields from chiral bisoxazolines (5a) with diethyl oxalate using NaOCH〓 as base for the first time. The structures of chiral multioxazolines and their intermediates, multi (β-hydroxylamide) s, were characterized by 〓H NMR, IR, mass spectra and elemental analysis. The catalytic activities and enantioselectivities of chiral multi (β-hydroxylamide) s (4) and chiral multioxazolines (5～8) were investigated by using acetophenone and β-acetonaphthone as former chiral ketone, KBH〓 or NaBH〓 as reductive reagent in chapter three.

在此基础上，对合成方法作了创新，以羧酸或酯为原料，在无催化剂的条件下与手性α-氨基醇反应，通过回流分水或脱醇的方法，一步反应合成了手性多噁唑啉（5～8），产率为89.2%～98.4%；以手性双噁唑啉（5a）为原料，在NaOCH〓的作用下，与草酸二乙酯反应，首次合成了呋喃类双嗯唑啉（6a），产率为72.9%～75.6%。

The E-TOF will also be feasible and practical to assist chemists in screening the optimal reaction condition or evaluating the overall efficiency of different catalytic systems for a specific asymmetric reaction.4.For the first time,we explored chiralγ-hydroxy-α,β-acetylenic esters,which were prepared via asymmetric alkynylation,as key intermediates to the synthesis of chiralγ-butyrolactones. This convergent and enantioselective approach to chiralγ-butyrolactones is practical and easily handled with protecting group free.

这一概念包括反应产率、对映选择性、配体用量以及反应时间四个重要反应参数，不仅适用同一反应不同催化体系的横向综合性评价，而且适用于某一特定反应催化体系的优化过程，有助于研究人员选择最佳的反应条件。4、我们发展了以手性γ-羟基-α，β-炔酸酯为关键中间体完成了手性γ-丁内酯类天然产物的对映立体选择性全合成，该关键中间体能够以我们的催化体系方便的对映选择性合成，之后的官能团转换方法成熟，易于操作，无需进行繁琐的官能团保护和脱保护过程，绿色经济。

A chiral phase transfer catalyst, N-benzyl quinine bromide, was synthesized from natural chiral compound. And 2,5-bimethyl-4-(3-nitrobenzene)-1,4-bihydrogenation pyridine-3--4-methyl formate (viz. nitrendipine) was synthesized by this chiral phase transfer catalysis, and characterized by elemental analysis, infrared spectrum,1H nuclear magnetic resornace, and X-ray single-crystal diffraction.Key words: ammonium; chiral phase transfer catalyser; crystal structure

通过对天然手性物质进行修饰合成手性相转移催化剂N-苄基溴化奎宁，并对目标分子2，5-二甲基-4-(3-硝基苯)-1，4-二氢吡啶-3-甲酸乙酯-5-甲酸甲酯进行不对称催化合成，并通过红外光谱和核磁共振氢谱对化合物进行了表征，用X射线单晶衍射法测定了该化合物的晶体结构。

Catalytic enantioselective reduction of imines and enamines represents one of the most straightforward and efficient methods for the preparation of chiral amines, which are not only important building blocks of many natrural products and chiral drugs, but also can serve as useful resolution reagents, chiral ligands and chiral catalysts.

中文摘要手性胺不仅是许多天然产物和手性药物的重要结构单元，而且也是非常有用的拆分试剂、手性配体和手性催化剂。

The basic concepts of chiral source , chiral pool, chiral intermediates of pesticides, and the rotes for preparation of chiral molecular compounds from chiral pools were introduced.

介绍手性源、手性池和手性分子化合物的基本概念；由手性池化合物制备手性衍生物；比较了手性化合物生物加工与化学加工过程的优、缺点，寻求高效、经济和最合理的综合工艺流程。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。