查询词典 asymmetric

The first part of this dissertation described a new effective method for asymmetric synthesis of,α,α-disubstituted amino acids from the asymmetric Strecker reaction products of aldehydes.

在本论文的第一部分，我们开发了一条以醛为原料，以不对称Strecker反应和不对称烷基化为关键步骤的合成α，α双取代氨基酸的有效方法，并对其立体选择性结果进行了机理探讨。

Based on English definition of the six properties which a relation R defined on a set A and utilizing the logical characteristic of implications, two aspects of ordered-pair and the matrix MR are considered, and the properties of the R is analyzed one by one. A few useful conclusions are summarized as determining the properey of the R. The following collections are also analyzed between reflexive and irreflexive, symmetric and antisymmetric, symmetric and asymmetric and among irreflexive, antisymmetric and asymmetric.

根据定义在一个集合A上的关系R的六个性质的英文定义，利用蕴含式的逻辑特点，从有序对和关系R的矩阵M两个角度对每个性质逐一进行分析，得出在判定关系R的性质时可用的结论，并且分析了自反性与非自反性之间、对称性与反对称性之间、对称性与非对称性之间、非自反性和反对称性以及非对称性之间的联系。

An contemporary expansion of the model has assumed evidently that asymmetric information spreads among firms and customers , and explored their differently asymmetric behaviors of responding to others ' changes of pricing and the causes of sticky prices so that the problem field of model has been expanded from oligopolistic market to monopolistically competitive market .

模型当代的一个扩展，明确假设了在顾客与厂商之间信息分布不对称，探讨了他们对于价格变动的反应不对称行为的各异性和粘性价格的成因，将微观模型的问题域从寡头市场扩展至垄断竞争市场。

An contemporary expansion of the model has assumed evidently that asymmetric information spreads among firms and cuscy110ers, and explored their differently asymmetric behaviors of responding to others' changes of pricing and the causes of sticky prices so that the problem field of model has been expanded from oligopolistic market to monopolistically competitive market.

模型当代的一个扩展，明确假设了在顾客与厂商之间信息分布不对称，探讨了他们对于价格变动的反应不对称行为的各异性和粘性价格的成因，将微观模型的问题域从寡头市场扩展至垄断竞争市场。

Expanding pinacol reductive coupling reaction into asymmetric one with both diastereoselectivity and enantioselectivity may lead to its application in synthesising medicaments and biologic active compounds with structure of vicinal diol. Asymmetric pinacol coupling reaction is also the most compact and effecient method in synthesizing chiral ligands or chiral auxiliary with C〓 symmetry.

将这一反应发展成为既有高度的非对映选择性，又有高度对映选择性的不对称偶联反应在合成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，同时不对称Piancol偶联反应也是合成C〓对称性的邻二醇多用途手性配体或手性助剂的最为简捷有效的方法。

Regulation is asymmetric because of its effect on income distribution. There are two models analyzing the social choice of asymmetric regulation, they are public interest theory of regulation and capture theory of regulation.

内容提要：管制制度的收入分配效应使得它往往具有非对称性，为了分析非对称管制制度的社会选择有两个均衡分析模型，分别建立在公共利益假定和利益集团假定基础之上。

Chiral ligands mentioned above and their complexes with acetate copper were used as enantio-selective catalysts in asymmetric cyclopropanation reactions of diazoacetate and 1,1-diphenyl ethylene. Investigations indicate that all of them reveal certain optical-selective capability, but chiral C2-symmetric 2,6-bispyridine ligands show better catalytic capability than chiral asymmetric schifF-base ligands.

选择了2个手性2，6-吡啶双噁唑啉配体和6个手性不对称席夫碱配体与醋酸铜形成的配合物作为催化剂，对重氮乙酸乙酯与1，1-二苯乙烯不对称环加成进行催化反应，发现这8个催化剂对1，1-二苯乙烯的不对称环丙烷化反应都表现出了一定的光学活性诱导能力，手性2，6-吡啶双噁唑啉-铜类具有比手性Schiff碱-铜类更好的催化性能。

Thirty-one new chiral phosphorus compounds have been synthesized starting from D-camphor,-alpha-phenylethylamine,-Betti base,-1-(4-nitrophenyl)-2-amino- propane-1,3-diol, L-amino acids (such as serine, phenylalanine, proline etc.) and their application as organocatalysts in asymmetric trimethylsilylcyanation of aldehydes and asymmetric borane reduction of prochiral ketones and ketimines were investigated.

该项目从D-樟脑、-alpha-苯乙胺、-Betti碱、-氯酶胺、L-氨基酸（如丝氨酸、苯丙氨酸、脯氨酸等）出发合成了31个新的手性磷化合物，研究了它们作为有机催化剂在醛的不对称硅氰化反应、潜手性酮的不对称硼烷还原反应以及亚胺的不对称硼烷还原反应中的催化效果。

The application of them as catalysts in the asymmetric ring-opening of epoxides was investigated. Through the screening of the catalysts, we found that some of them demonstrated good asymmetric induction ability in this reaction.

我们对非手性二硫代磷酸在手性Schiff碱和Ti〓的存在下对环氧化合物的不对称开环反应进行了研究，对手性Schiff碱进行了进一步的筛选。

In order to study the effect of PPh_2 group in the application of chiral ligands 4, 5, 7 and 8 to asymmetric reactions, two ferrocenyl amino alcohols 9a and 9b were Scheme 3 synthesized from chiral amino alcohol derived imines 3 (Scheme 3) and applied in the same asymmetric reactions.

为了探讨二苯氧膦基在配体参与不对称催化反应时对其催化活性和选择性的影响，合成了两个手性二茂铁基氨基醇配体9a和9b(Scheme 3)。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失