高灵敏示波电位动力学分析法测定茶单定

本文利用ＫＢｒＯ３和ＫＢｒ的氧化还原反应与茶单宁的溴代反应的速度差异，将动力学分析法与示波电位法结合起来，提出了测定痕量茶单宁的新方法。     

高灵敏示波电位动力学分析法测定茶单宁

本文利用KBrO3和KBr的氧化还原反应与茶单宁的溴代反应间的速度差异，将动力学分析法与示波电位法结合起来，提出了测定痕量茶单宁的新方法。在0．032mol／LHCl介质中，KBrO3和KBr浓度为0．0005和0．001mol／L时，方法的检出限为3．8μg／L，相对标准偏差为2．8％。调整上述试剂浓度，可使测定范围延伸几个数量级（从ng级到mg级）。该方法灵敏、简便、快速，且不受颜色等干扰。用于饮料、体液和茶树样品中茶单宁的测定，结果与酒石酸铁比色法相差—7．9％～5．5％。     

单宁作为共引发剂和交联剂制备高伸长率水凝胶

以过硫酸铵为引发剂(APS)、杨梅综合单宁(TA)作为共引发剂和交联剂,通过自由基聚合制备了高伸长率水凝胶(TIC-gel)。通过红外光谱(FT-IR)、核磁共振(~1 H-NMR)和浸泡尿素的方法研究了TA在TIC-gel中形成化学交联的机理。通过拉伸、压缩测试和流变学测试系统地分析了TIC-gel的力学性能和影响因素。结果表明:相比于传统化学交联水凝胶(PAM-MBA-gel),利用TA制备的凝胶具有高伸长率(2 250%)和高韧性(3.51 MJ/m3)。利用这一新的形成交联的方法所得的凝胶即使在高浓度时也能形成均匀的结构,可以很好地分散应力,为TIC-gel的高伸长率作出贡献。     

植物单宁化学研究进展

介绍了当前国内外对植物单宁化学的研究工作新进展,特别对单宁－蛋白质、单宁－金属离子、单宁－自由基反应机理等化学理论进行了论述,同时对单宁的药理和其它重要研究方向的应用价值作了简介。     

原子吸收光度法间接测定茶叶中单宁

基于乙酸铜与单宁生成沉淀，原子吸收光度法测定剩余铜的原理，间接测定茶叶单宁，样品前处理简单，测定单宁的线性范围为１￣４０ｍｇ／Ｌ，重复测定７次１０ｍｇ／Ｌ的单宁溶液，相对标准偏差为３．１６％，已用于几种不同茶样中单宁含量的测定。     

单宁的电化学氧化及伏安测定法

以玻碳电极（ＧＣＥ）为工作电极，ＫＨ２ＰＯ４－Ｎａ２ＨＰＯ４为支持电解质，通过循环伏安法首次观测到了单宁的不可逆氧化峰。在单宁浓度为１．０×１０～（－７）～１．２ × １０～（－５）ｍｏｌ／Ｌ范围内与其峰电流呈线性关系；检出限为 １．３×1０～（－８）ｍｏｌ／Ｌ。在中药五倍子浸提液中用标准加入法进行回收实验，其平均回收率为１００．６％。该法简便、快速，用１．０×１０～（－６）ｍｏｌ／Ｌ的单宁溶液重复测定１１次，ＲＳＤ为２．ｌ％。对其反应机理作了初步探讨。     

流动注射双安培法直接测定茶中单宁

基于不可逆电对的流动注射双安培检测原理，建立了快速检测茶叶中单宁的新方法。使用经阳极化处理的双铂电极，通过偶合单宁在一支电极上的催化氧化和氧化铂在另一支电极上的还原两个不可逆电极过程，在外加电位差为０Ｖ时，单宁的氧化电流与其浓度在１．０ × １０~（－６）～１．０ × １０~（－４）ｍｏｌ／Ｌ范围内呈线性关系，检出限为６．０ × １０~（－７）ｍｏｌ／Ｌ（Ｓ／Ｎ＝２）。连续４２次测定１．０ × １０~（－５）ｍｏｌ／Ｌ单宁，电流值ＲＳＤ＝１．２％。本法比现行国家标准方法简单、快速、灵敏，分别对市售绿茶、花茶、乌龙茶、红茶中单宁含量进行测定，结果令人满意。     

银缕梅叶片中单宁提取纯化工艺的研究

为了进一步提高银缕梅的应用价值,运用了分子生物学中的液氮冷冻技术,研究了银缕梅中单宁的提取及纯化工艺。结果表明,银缕梅叶片单宁最佳提取纯化工艺为:60%丙酮,提取时间15min,料液比1∶10,提取温度50℃,在此条件下单宁酸提取量为72.00mg·g~(-1)。纯化工艺为:5 mg·mL~(-1)上样,流速为1.5mL·min~(-1)过AB-8型大孔树脂柱,最后用60%乙醇洗脱。     

胶原纤维固化黑荆树单宁吸附V(V)的研究

研究了胶原纤维固化黑荆树单宁对V(V)的吸附。采用不同温度、pH值等条件进行吸附研究,并进一步探讨了固化黑荆树单宁的吸附动力学和吸附柱动力学及其吸附机理。结果表明,该材料对V(V)的吸附平衡符合Freund lich方程,温度对吸附平衡的影响不明显;吸附动力学可用拟二级速度方程来描述,该材料同时具有良好的柱动力学特性;V(V)的吸附过程可能存在三个反应,即V(V)与吸附剂之间发生氧化还原反应生成V(IV),V(IV)和-COOH之间发生离子交换反应,以及V(IV)与单宁的邻位羟基发生螯合。     

没食子单宁类化合物的合成研究

研究了三苄基没食子酰氯与两种葡萄糖衍生物（1,2-O-,1,2：5,6-二-O-异丙叉-α-D-呋喃葡萄糖）的酯化特性。合成了4种典型没食子单宁类化合物,基于薄层色谱与核磁谱图解析,这些化合物的结构得以确定。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

探究“铁的锈蚀条件”实验创新设计

设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。