表面膨胀粘度的测定研究

用不同浓度的NaCl和表面活性剂直链的十二烷基苯磺酸钠(LAS)、稳定剂聚丙烯酰胺和水所组成的泡沫体系为研究对象,通过表面压松弛的方法,利用计算机数据拟合,得到了计算表面膨胀粘度的方法。     

非霍奇金淋巴瘤的研究

非霍奇金淋巴瘤是具有很强异质性的一组独立疾病的总称,在常见恶性肿瘤中排名前10位,对人类健康威胁巨大。近年来,研究者们一直致力于非霍奇金淋巴瘤的发病机制、生物标志物及其治疗的研究,鉴于此,针对非霍奇金淋巴瘤的研究进行深入探讨。     

The problem of fullerenes. The chemical aspect

The preparation, structure, and reactivity of the family of polyhedral carbon clusters, novel allotropes of carbon, are reviewed.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 10–19, January, 1993.     

The thermolysis of dicarbonylcyclopentadienyliron dimer: The formation of biferrocene

The thermolysis of dicarbonylcyclopentadienyliron dimer in a sealed tube at 300°C has been reported to produce ferrocene, carbon monoxide, carbon dioxide, cyclopentadiene and elemental iron. We observe in addition to these products the production of biferrocene and elemental carbon. Thermolysis of carbonylcyclopentadienyliron tetramer (produced from the dimer by thermolysis in refluxing xylene) produces ferrocene, iron and carbon monoxidre; no biferrocene, carbon dioxide or elemental carbon are produced. A scheme is proposed to account for these products.     

塑料工业技术开发热点及其市场预测

本文简述了塑科将成为未来世纪的主要工业材料,介绍了80年代至本世纪末,世界主要国家塑料工业的主要品种,产量,生产能力;分析了90年代世界塑料市场供需状况,并重点探讨了中国塑料市场供需矛盾,预测了2000年需求总量,提出了今后发展应注意的关键问题。最后,重点探讨了世界塑料工业几个主要品种,今后发展趋势及一些关键技术的开发热点。     

The electrochemical reduction of maleimide: The synthesis of succinimide

The electrochemical reduction of maleimide has been investigated in the pH range 0–14 at a variety of electrode materials. The reaction scheme was found to fall into three distinct sections, depending upon the pH at which the reduction was performed. At low pH the reduction product was found to be succinimide, and the mechanism of its formation is described. At higher pH values, the hydrolysis of starting materials complicates the interpretation of the electrochemical measurements, but nevertheless the overalls reduction mechanism could be deduced. Polarographic data complement information obtained from rotating disc experiments, and comparison is made with the electrochemical reduction of phthalimide.     

The Formation of DNA Photodamage: The Role of Exciton Localization

The electronic structure during the formation of a cyclobutane pyrimidine dimer (CPD) between two thymine bases is investigated using semi‐empirical and first‐principles approaches. The dimerization of two isolated thymine bases is found to have no barrier or a very small barrier in agreement with previous studies suggesting low photostability of DNA. The well‐known high photostability of DNA can only be explained taking other factors into account. We investigate the role of the exciton location in the particular environment. Different model systems, from isolated thymine bases to an oligonucleotide in aqueous solution, are discussed. Analysis of the frontier orbitals allows one to understand the connection between the location of the exciton, the relative orientation of the thymine bases, and the observed reactivity.     

The synthesis of N-substituted ureas I: The N-alkylation of ureas

Summary Urea and N-alkylureas are N-alkylated in low yields using aprotic dipolar solvents, like dimethylsulfoxide, solid potassium hydroxide, and alkyl halides. Phase transfer catalysis with tetrabutylammonium chloride in refluxing toluene results in high yield regioselective N-alkylation of N-alkylureas by means of alkyl halides, tosylates, mesylates, and sulfates as alkylating agents and alkali hydroxide as the base — however, N-arylureas are not alkylated under these conditions. Kinetic studies point to a S_N2 type reaction which obeys the Kornblum rule.

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Zur Synthese N-substituierter Harnstoffe I: Die N-Alkylierung von Harnstoffen

Zusammenfassung Harnstoffe und N-alkylierte Harnstoffe werden in aprotisch dipolaren Lösungsmitteln, wie Dimethylsulfoxid, durch Alkylhalogenide in Gegenwart von Kaliumhydroxid in geringen Ausbeuten N-alkyliert. Phasentransferkatalyse mit Tetrabutylammoniumchlorid in kochendem Toluol ergibt aus N-Alkylharnstoffen bei Verwendung von Alkyl-Halogeniden, Tosylaten, Mesylaten und Sulfaten als Alkylierungsmittel und Alkalihydroxid als Base hohe Ausbeuten der regioselektiv N-alkylierten Derivate — allerdings werden N-Arylharnstoffe unter diesen Bedingungen nicht umgesetzt. Untersuchung der Kinetik ergab Hinweise auf eine S_N2-Typ Reaktion, die der Regel von Kornblum gehorcht.

     

The pectin of ginseng. The structure of the poly-galacturonide

Conclusions The partial hydrolysis of the pectin ofPanax ginseng C. A. Mey gives a polygalacturonide which has a linear carbohydrate chain consisting of residues of D-galacturonic acid in the pyranose form linked by -(1 4)-bonds.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 201–203, 1969     

分子设计在热塑性弹性体制备中的应用

本文综述了近年来基于分子设计原理制备的热塑性弹性体的研究报道,包括提高聚氨酯热塑性弹性热稳定性和柔韧性;用立构可控茂金属催化剂制备聚丙烯热塑性弹性体;热可逆共价交联聚合物和星型结构、棕榈树结构、哑铃形结构聚合物的研究.同时对乳液互穿网络型热塑性弹性体以及热塑性弹性体共混物进行了简要介绍.     

“物质的量”概念的探讨及其有关计算方法之我见

物质的量是物理化学和分子物理学这门学科范围的基本量。长期以来,人们习惯用当量,当量浓度及摩尔浓度等现已废弃的单位去计算。而当前国际单位制(SI)以物质的量作为基本量。为了使大家对物质的量能正确的理解和使用,本文特对其概念进行了讨论,并提出了与之适应的计算方法。     

考虑极性基团相互作用影响的疏水常数计算方法

通过对点价的修正,将分子连接性指数转变成为一种量子拓扑指数。由于改进后的量子拓扑指数能够很好地表达分子的体积和电性等结构信息,因此该指数与疏水常数计算中的极性基团相互作用有很好的相关性。实际计算表明,对于含有极性基团的分子,用该指数计算的结果更加精确。     

南海海绵Axinyssa aplysinoides的化学成分研究(三)

从南海海绵Ａｘｉｎｙｓｓａ　ａｐｌｙｓｉｎｏｉｄｅｓ中分离得到两个小分子化合物 Ｃ７Ｈ６Ｏ２和 Ｃ５Ｈ６Ｎ５Ｏ５。利用 ＩＲ、ＵＶ、ＮＭＲ、ＭＳ等分析手段确定了它的结构 为对羟基苯甲醛和胸腺嘧啶。     

2,5-二甲氧基苯胺的乳液聚合及聚合物结构表征

2;5-二甲氧基苯胺的乳液聚合及聚合物结构表征