用电解法评估纯铜和普通黄铜样品的质量

在用电解法采集纯铜和 普通黄铜样品时，根据样品的牌号确定样品的近似电化摩尔质量ｋ，选择合适的电解条件使电流效率为１００％，用Ｆａｒａｄａｙ定律ｍ＝ｋＩｔ计算采集样品的质量。     

Effect of coagulant temperature and composition on surface morphology and mass transfer properties of cellulose acetate hollow fiber membranes

Cellulose acetate (CA) hollow fibers were spun via the dry‐jet wet spinning technique under various external coagulant compositions and temperatures. The surface morphology of the resulting hollow fiber was examined using field emission scanning electron microscopy (FESEM) and tapping mode atomic force microscopy (TMAFM). The pure water permeability (PWP) and the retention of dextran of the hollow fiber were also measured. The results showed that both the temperature and composition can affect greatly the surface morphology and hence the permeation performance of hollow fiber membranes when the temperature was over 55°C and the dimethyl formamide (DMF) content was higher than 15%. The on‐line draw ratio increased with the coagulant temperature and DMF content (in the range of 0 to 10%) in the external coagulant. The ultimate tensile strength also increased when the fibers were coagulated in 5–10% DMF and at 70°C. The PWP increased with the DMF content in the coagulant and the coagulant temperature. The retention of dextran decreased with the increase of the DMF content in the coagulant and the coagulant temperature. Copyright © 2005 John Wiley & Sons, Ltd.     

A New Synthetic Route to Diastereomerically Pure Cyclopropane-Phosphorus Derivatives Utilizing the Chiron 5-L-Men-thyloxy-3-bromo-2(5H)-furanone and Racemic Dialkyl α-Hydroxyalkanephosphonate

ＩｎｔｒｏｄｕｃｔｉｏｎＣｙｃｌｏｐｒｏｐａｎｅ ｃｏｎｔａｉｎｉｎｇｎａｔｕｒａｌａｎｄｎｏｎｎａｔｕｒａｌｐｒｏｄｕｃｔｓｈａｖｅｒｅｃｅｉｖｅｄｃｏｎｓｉｄｅｒａｂｌｅａｔｔｅｎｔｉｏｎａｓｓｙｎｔｈｅｔｉｃｔａｒｇｅｔｓａｓｔｈｅｉｎｃｏｒｐｏｒａｔｉｏｎｏｆｔｈｅｒｉｇｉｄｉｆｉｅｄｃｙｃｌｏｐｒｏｐｙｌｍｏｔｉｆｉｎｔｏｂｉｏａｃｔｉｖｅａｎａｌｏｇｕｅｓｌｅａｄｔｏｃｏｎｆｏｒｍａｂｌｙｃｏｎ ｓｔｒａｉｎｅｄｍｏｌｅｃｕｌｅｓ .1,2 Ｓｕｃｈｍｏｄｉｆｉｃａｔｉｏｎｓａｒｅｅｘｐｅｃ…     

Aminoalkohole, 3. Mitt. Ein Verfahren zur Herstellung von enantiomerenreinen pharmakologisch aktiven N-substituierten β-Aminoalkoholen

Zusammenfassung Clorprenalin und Propranolol können mit dem vorgestellten Verfahren in sehr guter Ausbeute aus den O-MBF-geschützten Aminoalkoholen durch reduktive Alkylierung in enantiomerenreiner Form hergestellt werden. Bei der Synthese von enantiomerenreinem Midodrin, bei der in der letzten Stufe gemeinsam mit der O- auch die N-Schutzgruppe (BOC) abgespalten wird, müssen bestimmte Reaktionsparameter (Zeit, Temperatur) präzise eingehalten werden, um eine entsprechende Enantiomerenreinheit der Endprodukte (>95% ee) zu gewährleisten.

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Aminoalcohols III: Preparation of enantiomerically pure pharmacologically active N-substituted -aminoalcohols

Summary A synthesis of N-substituted -aminoalcohols is described starting from enantiomerically pure O-MBF- or O-MBE-protected -aminoalcohols which can be preparedvia LiAlH₄ reduction of O-protected cyanohydrines.

Herrn Prof. Dr.F. Sauter mit den besten Wünschen zum 65. Geburtstag gewidmet     

Complex specializations of the reduced Gassner representation of the pure braid group

We will give a necessary and sufficient condition for the specialization of the reduced Gassner representation to be irreducible. It will be shown that for , is irreducible if and only if .

     

纯拟内射模

本文引进了纯拟内射模的概念，讨论了该模的一些主要性质，证明了纯拟内射模保持有限直和，进一步地利用这类新模刻画了正则环的特征。     

定量分子结构与纯液体介质光致克尔常数关系

对一系列液体分子进行了理论计算，运用多元回归分析建立了分子结构与纯液体介质光致克尔常数之间的定量关系，从光与分子作用和分子与分子间相互作用的角度对光致克尔效应进行了探讨。结果表明，纯液体介质的光致克尔常数与分子的前线轨道能级（能隙）、偶极矩和空间内最负的静电势之间存在着良好的线性相关关系。     

只有纯虚谱的Hamilton算子

刻画了一类无穷维Hamilton算子的谱的分布情况,并得到了无穷维Hamilton算子只有纯虚谱的充分条件.最后,构造出具体的例子以说明判别准则的有效性.     

Synthesis of enantiomerically pure tertiary 1,2-aminoalcohols by the highly diastereoselective reductive ring opening of oxazolidines

A number of enantiomerically pure 1,2-aminoalcohols containing tertiary nitrogen atoms bearing chiral substituents have been prepared by highly diastereoselective reductive ring cleavage of oxazolidines derived from ketones and pseudoephedrine or ephedrine. The ring cleavage occurs with retention of configuration.     

The Gabriel–Roiter Measure for Right Pure Semisimple Rings

We show how the Gabriel–Roiter measure, introduced by Ringel in (Bull Sci Math 129:726–748, 2005 and Contemp Math 406:105–135, 2006), applies to indecomposable modules of finite length over right pure semisimple rings, and in particular to the study of the open problem whether any right pure semisimple ring is of finite representation type. Dedicated to the memory of Andrey Vladimirovich Roiter. Professor A. V. Roiter has died on 26 July 2006 in Riga, Latvia. He was born in 1937.