二中心的

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。

The teaching term took sixteen periods. The curriculum contained two topics,"acid and base", and "Taiwan's climate". Experimental treatments were teaching method. The research tools utilized in the study were " Science Concept Comprehension Test, Science-related Attitudes Scale, Problem Solving Ability Test and Questionnaire on the Attitude toward Science Teaching". A pretest administered before the experimental treatment and a posttest was held after the treatment. The data of SCCT, SRAS, and PSAT collected from pretest and posttest were analyzed by two-way ANOVA. Responses from the QAST were analyzed by ANOVA.

本研究的实验处理为以问题为中心的合作学习教学，研究工具包括「科学概念理解问卷」、「科学相关态度量表」、「问题解决测验」、「对自然科的教学态度问卷」、「教学检核量表」及「问题中心教学自我评估量表」，分析「科学概念理解问卷」、「科学相关态度量表」和「问题解决测验」资料时，以前测经验和教学法为自变项，后测为依变项，进行二因子变异数分析；「对自然科的教学态度问卷」采用单因子变异数分析；「教学检核量表」及「问题中心教学自我评估量表」则用来检核研究者的教学是否符合研究者的研究设计；在质性资料的部分，则分析学生的上课纪录、教师教学反省纪录及对自然科教学的态度问卷的理由。

A new multiclass SVM algorithm based on binary tree was introduced on E-mail filtering. It could convert multiclass problem to binary classification by constructing binary tree. The idea of clustering first and classification later was adopted, and the largest similarity between testing sample and sub-category center and the separation measure of sub-categories were calculated, in oder to construct the optimal class hyperplane of decision-making nodes.

提出一种基于二叉树的多分类SVM算法用于电子邮件的分类与过滤，通过构建二叉树将多分类转化为二值分类，算法采用先聚类再分类的思想，计算测试样本与子类中心的最大相似度和子类间的分离度，以构造决策节点的最优分类超平面。

Crystal structural analysis reveals that, because water molecules bond to Cu atoms, the dhbd ligand can only adopt a hydroxyl oxygen atom to bridge two reversed U-shaped subunits into a novel centrosymmetric dual-U-shaped tetranuclear Cu structure. Each U-shaped frame consists of two crystallographically distinct Cu atoms, two dpphen ligands and one coordinated water molecule.

晶体结构分析表明，由于水的配位阻断， 2，3-二羟基丁二酸根仅通过单羟基氧桥联两个U形双核亚单元形成具有一个对称中心的双U形四核结构，其中U型亚单元包含晶体学上不对称的2个Cu原子、1个2，3-二羟基丁二酸根、2个4，7-二苯基-1，10-邻菲咯啉和1个配位H2O分子。

A pivotal problem to recognize of the precise position of laser facula has been solved in the process of design work: Firstly the method of background-subtraction is used to eliminate or weaken the affect of background light. Secondly the image threshold segmentation operation and morphologic operation are used to locate the sketchy position of laser facula ; Then the new method of Extracting Edge are designed based on character of laser facula , by using this method in the search area the edges of laser facula can be extracted effectively; At last the optimum picture of laser facular is selected by using the triggering function of hardware and function of software. The exact result can be obtained only by image processing to optimum picture.

在设计过程中解决了精确确定激光斑中心位置这一关键问题：首先利用减背景法，消除或减弱背景光的变化对确定激光光斑中心的影响；再对减完背景后的图片进行阈值分割和二值化处理以确定激光光斑的粗略位置；根据本文激光光斑的特征，设计了一个有效的边界提取算法，对指定区域进行提取激光光斑边界操作，精确的确定激光斑中心位置；最后利用硬件的触发功能和软件编程实现了激光光斑最佳图片的判读，只有对最佳图片进行图像处理得到结果才是准确的。

The article, focusing on the thought orbit especially in the field of literature, emphasizing the inter-link between the changes of their thought, explaining the life choice of thought subject and taking the learning and thought idea of World Consciousness and World View as breakthrough points, depicts their social and moral bear and transcendality of their thought version. Contrasting their literary thoughts of organon and ontology with each other, the article explains the central role played by "tragedy" in their thought structure and homorganic and interdynamic relations between their best but last aesthetic "tragedy" and life "tragedy".

本文以描述王国维、鲁迅二人的思想轨迹为中心，其中又以揭示二人思想、诗学迁变的内在链接为描述重点，兼及思想主体的生命选择，以学术、思想的&天下意识&与&天下观&为切入点，凸显二者的社会、道德承担和思想眼界的超越性，对比二人文学思想之工具论与本体论暨&无用之用&与&善撄人心&、&境界&与&摩罗诗力&，解说&悲剧&在二者思想构造中的中心意义，阐发这种臻于至境的美学&悲剧&与二人臻于绝境的生命&悲剧&的同构与互动关系。

There are two positive results, proton and sodium that has been reported previously, and three candidates including succinate, phosphate and melibiose that was found in this study.

根据节点连结度的分析，找到了五个候选协同输送系统中的中心小分子，其中两个为已知的阳性资料，氢离子与钠离子，其余三个分别为琥珀酸盐，磷酸，蜜二糖，其中以蜜二糖为中心的输送系统只有一个，并不符合本篇所定义的协同输送系统，故舍弃之。

A modified γ-Al〓O〓 was prepared by a special precipitation method with aluminum nitrate solution containing a certain amounts of orthosilicic acid and ammonia aqueous solution. Compared with commercial γ-Al〓O〓, the modified γ-Al〓O〓 was an effecient catalyst for dehydration of tetrahydrofurfuryl alcohol to dihydropyran. The results revealed that the strong acid sites on the surface of the catalyst may play a crucial role in this reaction.

并以硝酸铝和氨水为原料，用沉淀法制备出一种高比表面和拥有较多强酸中心的γ-Al〓O〓，它在四氢糠醇开环脱水制备二氢吡喃的反应中有优良的催化活性，通过比较此γ-Al〓O〓和普通商业γ-Al〓O〓的Py-TPD图，发现强酸中心在制备二氢吡喃的反应中可能具有关键的作用。

We can compute three dimensionalvelocity distribution on a planar domain of flow field based on conventional ParticleImage Velocimetryand 3D reconstruction theory of stereophotogrammetry.

在流场空间两个不完全交叠的体积元(映射为两个摄影机象平面上以同名点为中心的两个相同大小的判读小区域)中的示踪粒子的统计性质都能同样表征这两个体积元公共中心的流体运动的假设下，PIV技术与体视三维重建理论的结合，可以将原PIV技术中二维统计平均的概念扩展为三维统计平均，并且在确定体积元公共中心位置之后，直接实现空间流体体元的三维位移重建。

Henry Rambo II the center of Bay Square Garden will reach 6000 square meters, one, two green area will reach 10,000 square meters.

亨利兰博二湾的中心花园广场将达到6000平方米，一，二绿地面积将达到一点○万平方米。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐