二-十进制

Therelationship of the amount of catalyst and the ee% of product was seen to be negative nonlin-ear. Catalyst 3 was used in the enantioselective addition of diethylzinc to aromatic aldehydesand gave good results. The configuration of products was determined by the configuration ofthe catalysts' chiral carbon linked with hydroxy group. Using β- amino alcohols bearing only one chiral center as catalysts for the enantiose-lective addition were studied. D-N, N-dialkyl-2-amino butanol gave poor catalytic effect be-cause of their structure. The configuration of the product is the same as the catalyst. Anotherkind of β- amino alcohols - phenylglycine derivatives and valine derivatives have chiralcenter on the carbon linked with amino group. Catalyzed by-phenylglycine derivatives 6,7, 9, 10, the reactions gave satisfied results. The optical yields exceeded 80%.

在探讨了含有两个手性中心的β-氨基醇之后，选择了只有一个手性中心的β-氨基醇，一是手性中心为连羟基的手性碳原子：D-N，N-二烷基-2-氨基丁醇；二是手性中心为连氨基的手性碳原子：D-苯基甘氨酸衍生物和L-缬氨酸衍生物。D-2-氨基丁醇的催化效果不太好，这与其结构的空间位阻较小有关系，反应产物与连羟基手性碳构型一致；由苯基甘氨酸和缬氨酸出发合成五种β-氨基醇6-10，研究了不同ee％的-6作用下的二乙基锌-苯甲醛加成反应，发现该催化剂具有不对称放大效应；-7，9，lO的催化效果也比较令人满意，光学产率80％以上，所得产物构型与催化剂构型一致。

Applicants are required to submit (before June 30 each year) two copies of application form, one photostatic copy of their diploma, transcript of academic records, three letters of recommendation including one by a teacher of Chinese language, plans of study written in Chinese, biography written in

申请人须於每年四月三十日前检附申请表二份、毕业证书、全部成绩单、三份教师推荐书、中文读书计划、中文自传、财力证明书、健康证明书壹份及二吋半身相片二张，送达本校审查。

Applicants are required to submit (before June 30 each year) two copies of application form, one photostatic copy of their diploma, tran script of academic records, three letters of recommendation including one by a teacher of Chinese language, plans of study written in Chinese, biography written in Chinese, certificate of finances, record of medical examination issued by a practicing physician, stating the general condition of health of the applicant and two recent bust photographs, to Hsuan Chuang College for consideration.

申请人须于每年四月三十日前检附申请表二份，毕业证书，全部成绩单，三份教师推荐书，中文读书计划，中文自传，财力证明书，健康证明书壹份(含免疫缺乏病0筛检)及二0半身相片二张，送达本校审查。

In the conformation change process, the second hyperpolarizability values of system and for singlet are negative system (a of 45° and 135° with the exception, and less than the absolute value of all triplets. The second hyperpolarizability values of system for singlet and triplet states are positive and in molecular close plane configuration time, the value of triplet is greater than that of the singlet.

在构象变化过程中，体系和单重态的二阶超极化率均为负值体系(a的45°和135°除外，且绝对值都小于三重态的二阶超极化率值，体系的单三重态二阶超极化率值均为正值，且在分子接近平面构型时，三重态的γ值大于单重态。

The Dabie Mountains are unique among ultrahigh pressure metamorphic terranes in having the most profound post collisional plutonism The Mesozoic shoshonitic and calc alkaline intrusive rocks can be divided into three groups with different isotopic ages, rock assemblages and chemical features Group I consists of late Triassic (~ 210 Ma) mafic monzodiorites It could have been generated by partial melting of enriched subcontinental lithosphere mantle due to slab breakoff Group II consists ma...

第 I组，主要由晚三叠世（约210 Ma）二长闪长岩辉长岩体组成，它可能是在板片断离过程中富集的大陆岩石圈地幔部分熔融的产物；第I I组，由中侏罗世－早白垩世（160～120 Ma）的角闪石英二长岩、黑云母二长花岗岩和正长花岗岩组成，主要是由幔源岩浆的分离结晶与地壳混染共同作用的产物；第II I组，以白垩纪（125～95 Ma）的花岗岩和花岗斑岩为代表，是在热穹窿作用过程中大别杂岩深熔作用和高度演化的产物。

In this paper poly and monomethoxypoly with different molecular weight were used as raw material.

本论文通过不同的合成方法，利用不同分子量的聚乙二醇和甲氧基聚乙二醇为原料，制备了不同类型的聚乙二醇衍生物。

When thepolynomial has at least two simple real roots,sequences of critical values of timedelays corresponding to each positive root can be derived.

而当该多项式有二个及二个以上的简单正根时，稳定性切换次数主要取决于两方面：一是该多项式的正根的个数，二是该多项式的每个正根对应的临界时滞序列中相邻两项差的大小关系来确定。

Optimal process conditions for preparing N,N'-ethylenediamine diacetic acid: Potassium cyanide was combined with formaldehyde and ethylenediamine at a mole ratio of 2.4 to 2.4 to1, at temperature 18℃,and then was hydrolyzed for 8 hours.

通过单因素分析，合成N，N′—乙二胺二乙酸的最佳反应条件为：反应温度为18℃，水解时间为8 小时，甲醛∶氰化钾∶乙二胺的摩尔比为2.4∶2.4∶1。

By using ethanol precipitative pretreatment and rectification patent technology,the product 1,3-propanediol with purity of 99% had been harvested,the seperation yield of 1,3-propa...

采用发酵液醇沉预处理、再精馏的专利技术可分离得到纯度大于99%的1，3-丙二醇产品，分离收率大于85%，产品质量达到了聚对苯二甲酸丙二酯聚合反应的要求。

As a precursive work of polymerization directly from vesicles, a polymerizable surfactant, allyl dodecyl dimethylammonium bromide was synthesized, and spontaneous stable vesicles were formed from aqueous solutions of ADDB and sodium dodecyl sulfonate in equimolar composition.

作为可聚合囊泡制备的前期基础工作，研究了一种可聚合的囊泡体系：1-丙烯基－2，2，二甲基－十二烷基溴化胺和ADDB与十二烷基磺酸钠的等摩尔比混合体系。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。