SOLUTIONS TO TEXT PROBLEMS 19.1 (b) The four carbon atoms of crotonic acid form continuous chain. Because there is a double bond between C-2 and C-3, crotonic acid is one of the stereoisomers of 2-butenoic acid. The chem

SOLUTIONS TO TEXT PROBLEMS 21.1 Ethyl benz emuale cannor undergo the Claisen condensation, beca use it has no protons on its a- t has ho ts a-carbon on its a- atom and so cannot form an enolate Ethyl pentanoate and ethyl phenylacetate can undergo the Claisen condensation

Chlorotoluene Benzyl chloride Of this group only benzyl chloride is not an aryl halide; its halogen is not attached to the aromatic ring but to an sp-hybridized carbon. Benzyl chloride has the weakest carbon-halogen bond, its measured carbon-chlorine bond dissociation energy being only 293 kJ/mol (70 kcal/mol). Homolytic cleavage of this bond produces a resonance-stabilized benzyl radical

Look at the drawing from a perspective that permits you to see the carbon chain oriented ver tically with the aldehyde at the top and the Ch,oh at the bottom. Both groups should point away from you. When examined from this perspective, the hydrogen is to the left and the hydroxyl to the right with both pointing toward you

The order of decreasing sequence rule precedence is H,N->HSCH2->-Co2\>H- When the molecule is oriented so that the lowest ranked substituent () is held away from us, the order of decreasing precedence traces clockwise path CH,SH Clockwise;thereforeR The reason why L-cysteine has the configuration while all the other L-amino acids have the S configuration lies in the fact that the-CHSH substituent is the only side chain that

CONTENTS Preface xxv INTRODUCTION he Origins of Organic Chemistry 1 Berzelius, Wohler. and vitalism 1 The Structural Theory 3 Electronic Theories of Structure and Reactivity 3

液力传动在传递动力的过程中,有能量损失。 包括三种:液力损失、容积损失、机械损失。 损失的表示用液力效率,容积效率 机械效率(注意:在这里与工程习ng一 致,便于|n卖文献,效率下标的表示与《流体机 械原理》中表示不同)

串匹配(String Matching)问题是计算机科学中的一个基本问题,也是复杂性理论中研 究的最广泛的问题之一。它在文字编辑处理、图像处理、文献检索、自然语言识别、生物 学等领域有着广泛的应用。而且,串匹配是这些应用中最耗时的核心问题,好的串匹配算 法能显著地提高应用的效率。因此,研究并设计快速的串匹配算法具有重要的理论价值 实际意义

一、作者署名的中文书籍 1.丁友肪、陈宁编普通微生物遗传学南开大学出版社天津1990 2.马誉主编抗菌素(第三版)人民卫生出版社北京1965 3.王定昌编著工业废水生产单细胞蛋白中国轻工业出版社北京1991

Ei Compendex Web是《工程索引》的网络版,包括光盘版Ei Compendex和 Ei Page One两个数据库的内容。 Ei Compendex Web所报道的文献来源于5000多种工程类期刊。 其中2600种是 Ei Compendex光盘数据库所收录的期刊,2500种是 Ei Page One数据库收 录的期刊。来自Ei Page One数据库的记录绝大部分都不带文摘,属题录报道形式,而且 所有记录都没有主题标引项。 Ei Compendex Web按年代分为三个库: Ei Compendex Web70s(970~1979),ei Compendex Web8s(1980~1989)和Ei Compendex Web90(1990~现在)。70年代、80 年代两个库只包括 Ei Compendex数据库的内容,从1990年开始,在90年代库中增加了 Ei Page One数据库中的内容