1,2—双[水杨酰硫脲基]乙烷的合成

取代硫服类化合物具有多种重要的生物活性,如抗结核ｌ‘］、抗真菌、除草［’］、驱鼠ｌ’］及调节植物生长［‘１等功能。我们设想,如果能将具有生理活性的基因,如水杨酸基、硫晚基结合在一个分子中,构筑成双水杨酸硫晚类化合物分子,其中含有氧、氮、硫多种原子,可作为电子给予体,提供电子对和多种离子作用,预期新化台物会有更强的生物活性、配位金属阳离于的性能。本文设计合成１,２一双（水杨酚硫肥基）乙烷３。合成路线如下。水杨酸异硫氨酸酯２１５］３０ｎｕｎｏｌ水杨酸的４０ｍｌ苯溶液中加入１２ｍｍｏｌ三氯化磷１０ｍｌ…     

O3势能面和振动激发态的理论研究

由于O3在大气化学中的重要作用，近年来针对它的实验和理论研究皆较活跃．尽管对O3的高振动激发态已进行过广泛的研究［“］，得到过多种由实验光谱定出的势能面［‘，’］或由从头算得到的势能函数【‘］，但由于近年来又增加了一些新的高精度的振转光谱实验数据k，’」，而以     

食醋氨基酸指纹图谱的建立及特征分析

采用全自动氨基酸分析仪对液态发酵芳香醋、液态发酵苹果醋、固态发酵粮食酿造食醋和配制食醋等4种食醋中氨基酸进行测定,计算各氨基酸的峰面积比例,利用SPSS软件绘制食醋中氨基酸指纹图谱,并进行聚类分析。芳香醋、苹果醋和粮食酿造食醋中氨基酸质量浓度分别为0.80~1.99g·L~(-1),0.01~0.98g·L~(-1)和2.79~10.74g·L~(-1)。配制食醋基本不含氨基酸。指纹图谱能够较好区分出芳香醋、配制食醋,并且可以识别出来源相同的样品。聚类分析可按照不同发酵方式、产地及原料对食醋进行较好的归类。     

（2R,3S）—2甲基—3—羟基戊酸甲酯的手性合成

１引言烟草甲ＬａｊｓｔｏｄｅｒｍａｓｅｒｒｉｃｏｒｎｅＦａｂｒ。ｉｎｓ是一种主要危害烟草、香烟、干燥植物以及谷物、面粉的农业害虫。这种害虫在我国主要分布在淮河以南地区以及世界各地的温暖地带［‘］。（２,３Ｓ）－２一甲基一３一羟基成酸甲酯是我们设计的合成烟草甲性信息素的一个重要中间体。我们以丙快醇为基本原料合成了该化合物。丙炔醇参照文献ｌ’］方法制得２一戊炔一ｌ一醇２,催化还原条件下,炔键可被部分加氢得到（Ｑ－２一戊烯一卜醇３。在四异丙氧基钛、Ｄ－（）一酒石酸＄［Ｊ４Ａ分于筛催化条件下,顺式烯丙醇…     

对《化学》课本中一些插图的商榷

插图是教材的重要组成部分。教材中的插图必须注意科学性、艺术性。现行的中师、中学《化学》课本中有一些插图科学性较差,给教学工作带来一些麻烦,提出来和同行们商榷。1 显示的实验装置安装不妥11 有关铁架台的装置图铁架台的使用注意事项之一是“铁夹所夹的方向应与铁架台底座相同”以防使重心超出底座之外,造成装置翻倒。课本中“制取氨气的装置”图1［1］欠妥。从图2可以看出,图中铁夹所夹的方向与铁架台底座垂直,使重心超出底座之外。同样,以下图3［2］、4［3］、5［4］、6［5］都存在此类问题,只有图7［6］是正确的。图1 制…     

钌(Ⅱ)-联吡啶-丙酮酸-Ce(Ⅳ)化学发光体系测定人血清中丙酮酸的研究

丙酮酸是人体中不可缺少的有机酸，它的含量直接或间接地反映人的身体状况．通常的测定方法有氧化酶化学发光洁「“，氧化酶一过氧化酶双层改良电极的化学传感器法’‘’以及高效液相色谱法［’］等．这些方法的缺点是灵敏度低，操作繁杂．AndrewW．Knight［‘］报道的电致化学发光法虽然具有较低的检测限，但由于其发光行为在电极表面进行，发光面积小使其检测限和线性范围受到限制，另外，由于电极的吸附作用，使得电致化学发光洁的干扰因素较多．钉（！）一联毗院是一种常用的电致化学发光试剂，也是一种较好的化学发光试剂．在碱性条…     

μ—4,4‘—联吡啶桥联三核Cu（Ⅱ）配合物的合成和磁性

合成了３种以４，４’－联吡啶为配体的三核环状Ｃｕ（Ⅱ）配合物［Ｃｕ３（４，４＇－ｂｐｙ）３．（ｐｈｅｎ）３］（ＣｌＯ４）６．２Ｈ２Ｏ（１），［Ｃｕ３（４，４＇－ｂｐｙ），（ｂｐｙ）３］（ＣｌＯ４）６．Ｈ２Ｏ（２）和［Ｃｕ３９４，４＇－ｂｐｙ）３．（ＮＯ２－ｐｈｅｎ）３］（ＣｌＯ４）６．６Ｈ２Ｏ（３）。经元素分析，电导，ＩＲ，电子光谱，ＥＳＲ，磁化率等方法进行了表征，推定该配合物具有以４，４’－联吡     

复盐K2Mg(IO3)4 2H2O的热力学性质

由于碱金属碘酸盐晶体在电学性质的利用上有重要价值和发现碘酸盐晶体非线性性质［‘］，七十年代以来，Vinogradov等对碘酸盐-碘酸-水系统发生了极大的兴趣，做了大量研究工作［’－‘］，发现在碘酸盐．碘酸一水三元体系里有碘酸盐复盐K2M（IO3）4·2H2O（M＝Mn2＋、Co2＋、N     

O／W微乳液中聚邻甲苯胺超微粒子的制备

聚邻甲苯胺具有较高的电导率、较好的贮存电荷的能力和良好的环境稳定性，因而具有较大的应用价值［’－‘j，其合成方法主要有电化学合成法和化学合成法［‘·’J．化学会成法所得聚邻甲苯肢的粒子一般大于100urn．近年来，以表面活性剂聚集体微乳液、溶致液晶为介质，制备超微粒子材料已为人们所关注「’－’］．以微乳液为介质进行聚合反应亦引起重视，但大部分微乳液聚合都是在四组分微乳液（表面活性剂、助表面活性剂、单体和水）中进行‘”·“‘．近年来，某些油溶性单体已成功地在无助表面活性剂的三组分微乳液中聚合［‘’·‘’1…     

氯代甲苯异构体双电荷离子电子捕获诱导解离谱研究

研究了４种Ｃ７Ｈ７Ｃｌ异构体在７０ｅＶ电子轰击下产生的［Ｃ７Ｈ７Ｃｌ］＾２＋、［Ｃ７Ｈ６Ｃｌ］＾２＋．和［Ｃ７Ｈ５Ｃｌ］＾２＋ ３种双电荷离子的电子捕获诱导解离（ＥＣＩＤ）反应。分子离子的ＥＣＩＤ反应明显的邻位效应，表明其结构仍保持中性分子的结构特征；而由各异构体产生的［Ｃ７Ｈ６Ｃｌ］＾２＋．和［Ｃ７Ｈ５Ｃｌ］＾２＋离子异构化成同一结构。３种双电荷离子ＥＣＩＤ反应的产物与离子所带电子的奇偶性有关，     

LOW DENSITY POLYETHYLENE/CLAY NANOCOMPOSITES MODIFIED BY ETHYLENE COPOLYMERS： EFFECTS OF FUNCTIONALIZED SEGMENTS ON MORPHOLOGY

Melt extrusion was used to prepare binary nanocomposites of ethylene copolymers and organoclay and trinary nanocomposites of low-density polyethylene （LDPE）, ethylene copolymer and organoclay. X-ray diffraction （XRD） and transmission electron microscopy （TEM） were used to analyze the structure of the clay phase and the morphology of the nanocomposites. Influences of the comonomer in the copolymer and the content of the copolymer on the morphology of the resulting nanocomposites were discussed. The binary and the trinary composites may form intercalated or exfoliated structures depending on the interaction between the copolymer and the clay layers and the content of the copolymer.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Thermodynamics of dissolving and solvation processes for benzoic acid and the toluic acids in aqueous solution

Experimental data are presented for the solubility in water of benzoic and toluic acids from 5° to 65°C. From the solubility the molality of the monomeric form of the acid is calculated using literature data for both ionization and dimerization of the acid. These data for the monomer combined with data from the literature for vaporization of the solid and ionization in both the gas phase and the aqueous phase yield entropy and enthalpy changes for the solvation of molecular and anionic forms of the acid. A similar procedure is also applied to literature data for the solubility of benzene in water. It is shown that the hydration entropies of the monomeric forms are a linear function of their partial molar volumes. It is concluded that hydration of the undissociated o-toluic acid may be crucial to the increased acidity of that acid compared to benzoic acid.     

The modification of the triple helical structure of gelatin in aqueous solution 3. The influence of nonionic surfactants

Using CD-measurements the influence of nonionic surfactants (dodecyl polyoxyethylene, ethoxylated para tert. octyl phenol, commercial nonionic WON 100 and octyl diethyl phosphinoxid) on the secondary structure of gelatin in aqueous solutions was investigated. At surfactant concentrations smaller than the c.m.c. the triple helical content of the gelatin is increased. At concentrations exceeding the c.m.c. the triple helical content decreases. Chain reversals of the peptide chains after the destruction of the triple helical structure were shown to appear in acidic environment at 298 K. This destruction is reversible by rechilling the solution.     

Chain dynamic parameters for some acrylic polymers

The dielectric relaxation data of Ishida et al. on a number of acrylic polymers are represented in terms of the relaxation function proposed by Havriliak and Negami using the multi-response techniques developed by Havriliak and Watts. Two of the parameters of this function are interpreted in terms of a temperature dependent distribution of relaxation times. In this method of interpretation the breadth of the distribution function is temperature-dependent while the skewness is not. The temperature dependence of the breadth of the distribution function is similar for most of these acrylic polymers.The parameters of the relaxation function are also interpreted in terms of Mansfield's model which represents intra- and inter-molecular interactions in terms of springs and dash pots. Briefly, increasing the side chain length for the methacrylate series increases the inter-molecular relaxation time which may be due to an increase in the entropy of activation for the orientation process. The difference between the one acrylate in this study and the four methacrylates of the series is a reduction in the intra-molecular relaxation time, apparently due to the lack of the alpha methyl group.     

SYNTHESIS OF CROSS-CONJUGATED （p-PHENYLENE）S-POLY（p- PHENYLENEVINYLENE）S HYBRIDS WITH LOW CONTENT OF STRUCTURAL DEFECTS

The novel shish-kebab-type liquid crystalline cross-conjugated （p-phenylene）s-poly（p-phenylenevinylene）s hybrid was synthesized through Gilch polymerization. Their structures and properties were characterized by NMR, GPC, DSC, X-ray diffraction and polarizing optical microscope （POM）. ^1H-NMR investigation of the polymers indicates that the shish-kebab-structure has a strong ability to suppress the structural defects in the polymers. The polymers are enantiotropic liquid crystals. The melting point （Tm） of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The mesophase was identified by X-ray diffraction method. They showed not only a smectic LC phase, but also a strong green fluorescence in chloroform. The maximum absorption band of the ＂kebabs＂ of the two, 5-bis（4＇- alkoxyphenyl）benzene at 280 nm did not appear in absorption spectra of the polymers. The same phenomena were also observed in the fluorescence spectra. These results imply that the polymers have formed a cross-conjugated uniform structure and achieved an extended n-conjugation polymer.     

Comparative study on the reactivity of propargyl and alkynyl sulfides in palladium-catalyzed domino reactions

Three types of sulfides bearing a propargyl or an alkynyl moiety have been studied in cyclocarbopalladation/cross-coupling domino palladium-catalyzed sequences. The reactivity of different types of sulfured starting materials has been compared as well as the difference in behavior of these compounds depending on the type of cross coupling ending the domino sequence. It appeared that these cascades were constantly more efficient on the propargyl benzyl thioether. In addition, it has been demonstrated that domino sequences ending with Stille, Suzuki–Miyaura, or Mizoroki–Heck lead efficiently and selectively to the desired cyclized products. Notably, when the introduction of an alkyne is targeted at the end of the cascade, it appeared that the Sonogashira coupling leads every time to the desired cyclic product in the mixture with the product resulting from the direct coupling between the aryl moiety of the substrate and the alkyne used as partner. Finishing the domino sequence with a Stille coupling instead of a Sonogashira one allowed improving significantly the ratio of the mixture in favor of the desired cyclized compound.     

Influence of nozzle geometry on polystyrene degradation in convergent flow

Polymer degradation is readily observed in flows where the extensional component surpasses the rotational component of the velocity gradient. This type of flow is conveniently obtained by pushing a liquid into a convergent channel across an orifice. Kinetics of chain scission is sensitive to subtle modification of the coil conformation, which in turn depends on the details of the pervading flow field. By changing the orifice diameter and the conical angle of the inlet, it is possible to modify the spatial distribution of the velocity gradient, and hence, the residence time of a fluid element in the high strain-rate region. Degradation yields, measured under -conditions in decalin by Gel Permeation Chromatography, showed a strong dependence on the fluid velocity at the orifice, but not on the magnitude of the strain-rate. This result is contrary to the common belief that assumes viscous friction, proportional to the strain-rate, is the determining factor for the scission rate of a bond under stress. Rather, experimental findings tend to indicate that the driving force for chain scission was provided by the energy accumulated in the coil during the flow-induced deformation process. The sharp propensity for mid-chain scission was maintained regardless of the nozzle geometry.Dedicated to Prof. W. R. Pechhold on the occasion of his 60th birthday     

A real-time drawing study on solution-crystallized UHMW-polyethylene — comparison with conventional x-ray results

Solution-crystallized ultra-high molecular weight polyethylene (UHMW-PE) can be drawn in the solid state to very high draw ratios, leading to materials with excellent mechanical properties. Very recently, the drawing process has been studied via different x-ray techniques, on the basis of which a deformation mechanism was proposed which could satisfactorily explain all observations. However, like most deformation studies performed in the past, the measuring conditions were quite different from the actual drawing conditions. Cooling drawn samples to room temperature as well as relieving the stretching force may give rise to the introduction of artefacts, leading to misinterpretation of the results. In order to exclude this possibility an x-ray study was performed on solution-crystallized UHMW-PE in real time, i.e.,during the deformation process, using the benefits of synchrotron facilities. Comparison of these results with x-ray results obtained via the conventional method shows that the latter method can be used without any problems for a qualitative study on the solid state drawing of ultradrawable UHMW-PE. One of the major advantages of the real-time method is the possibility to study the initial elastic deformation region.Presented in part at the Rolduc Polymer Meeting-2, April 1987, Kerkrade, The Netherlands.     

Annealing of Polypropylene/Polyethylene Blends Near to the Melting Points in TMDSC

Annealing experiments have been carried out just below the melting temperature of both polyethylene (LLDPE) and polypropylene (PP) and their blends. The total melting enthalpy measured after the annealing cycle was greater by 10-15% with respect to the value having been measured before it. During the annealing period the heat capacity decreases to a lower value within the first 2-3 min. Heat capacities of PP (either in pure form or in the blends) measured during the heating cycle following the annealing cycle have the same value as during the cooling section. The heat capacities of the LLDPE in the heating cycle following the annealing were those of the preceding heating cycle. The total heat flows in the cooling section following the annealing cycle were greater than those in another cooling cycle at the same temperatures indicating that the crystallisation takes place during the cooling rather than during the annealing periods. The presence of LLDPE decreases the crystallisation temperature of PP. The presence of SEBS in the blend results in a greater crystallisation temperature than that of pure PP. The crystallisation temperature of LLDPE increases with increasing levels of PP. This revised version was published online in July 2006 with corrections to the Cover Date.