茶叶多糖及其铈配合物对质粒DNA及有机磷农药的降解作用

以茶叶多糖(TPS)为配体与四价的铈(Ce^4 )结合,形成了水溶性的茶叶多糖铈配合物(Ce-TPS)。在中性条件下,TPS及Ce-TPS对质粒DNA(Pllasmid DNA)有一定的裂解作用,对有机磷农药毒死蜱有很强的降解作用。将TPS及Ce-TPS应用于大田,可有效降低菠菜中毒死蜱及乐果残留量,比对照低5倍以上,其中Ce-TPS处理8d后毒死蜱及乐果残留量均低于国家标准(≤1．0mg．kg^-1)。     

铈（Ⅲ）,铈（Ⅳ）与植酸生成的固态配合物的研究

铈（Ⅲ）、铈（Ⅳ）与植酸生成的固态配合物的研究黎晓霞杨瑛＊刘建民杨汝栋（兰州大学化学系兰州７３００００）关键词铈（Ⅲ），铈（Ⅳ），植酸，固态配合物１９９６－１１－２０收稿，１９９７－０５－２６修回植酸（Ｈ１２ＩＨＰ）作为沉淀剂已被用于Ｔｈ４＋的定量测...     

铈(Ⅲ)-氨基酸-咪唑三元配合物的表征和循环伏安行为研究

合成了铈（Ⅲ）－色氨酸－咪唑和铈（Ⅲ）－苯丙氨酸－咪唑三元配合物,对配合物进行了元素分析、摩尔电导测试、热重－差热分析及红外光谱分析,确定了配合物的组成和成键特征,并用循环伏安法研究了铈（Ⅲ）离子、铈（Ⅲ）与氨基酸及咪唑混合溶液、铈（Ⅲ）二元及三元配合物在玻碳电极上的电化学行为。实验结果表明,在－０．１０～１．１０Ｖ（ｖｓ．ＳＣＥ）电位扫描范围内,两种铈（Ⅲ）三元配合物显示了安全不可逆的电子迁移过     

邻苯二酚衍生物与稀土元素配位反应的研究(Ⅴ)——3,4-二羟基苯甲酸与铈(Ⅲ)的配位与转型反应

研究了稀土元素铈（Ⅲ）离子与３，４－二羟基苯甲酸（Ｈ３Ｌ）在水溶液体系中生成羧基配位化合物的条件，表征其组成为Ｃｅ（Ｈ２Ｌ）２（ＯＨ）·３Ｈ２Ｏ，并研究了该配合物在一定条件下，铈离子由羧基配位反应变为由两个邻酚羟基配位的配合物［Ｃｅ（ＨＬ）ｎ］的转型反应及氧化成铈（Ⅳ）配合物的反应．     

钛铁试剂分光光度法直接测定轻稀土中的铈

利用铈的变价以及Ｃｅ（Ⅳ）－Ｔｉｒｏｎ配合物在不同酸度条件颜色的特殊性，建立了无需预先分离而直接测定混合稀土中铈含量的分光光度法，在ＰＨ为９．０条件下，借助空气的氧化，Ｃｅ（Ⅲ）和Ｃｅ（Ⅳ）都与Ｔｉｒｏｎ形成Ｃｅ（Ⅳ）－Ｔｉｒｏｎ配合物。该配合物在ＰＨ为５．０时呈亮黄色，在４３５ｎｍ处有最大吸收。     

邻苯二酚衍生物与稀土元素配位反应的研究（V）：3,4—二羟 …

研究了稀土元素铈（Ⅲ）离子与３，４－二羟基苯甲酸（Ｈ３Ｌ）在水溶液体系中生成羧基配位化合物的条件，表征其组成为Ｃｅ（Ｈ２Ｌ）２（ＯＨ）．３Ｈ２Ｏ。并研究了该配合物在一定条件下，铈离子由羧基配位反应变由为两个邻酚羟基配位的配合物（Ｃｅ（ＨＬ）ｎ的转型反应及氧化物铈（ＶＩ）配合物的反应。     

全反式维甲酸合钐（Ⅲ）配合物与DNA作用的研究

以荧光法，粘度法和圆二色谱法研究了全反式维甲酸合钐（Ⅲ）配合物与DNA 的作用，结果表明，该配合物可使DNA的粘度增加，引起DNA圆二色谱中的负峰发生 较大变化，使EB－DNA体的荧光强度降低，DNA热变性温度升高，该配合物的荧光强 度在DNA存在时有较大的增加，据此推断，该配合物主要以嵌入方式与DNA作用，这 咱作用方式可能是该配合物对HL－60，EJ癌细胞瘤株有较强抑制作用的原因之一。     

阿霉素─铁(Ⅲ)配合物的电化学特征及其与DNA结合作用研究

采用示波极谱法和循环伏安法研究了3公铁离子Fe（Ⅲ）与阿霉素（ADM）配合物的电化学特性．在生理pH条件下，Fe（Ⅲ）与ADM形成2：1的稳定配合物，Fe（Ⅲ）的配位使ADM在更负的电势下才能还原，这与其心脏毒性减轻密切相关．采用线性扫描、吸收光谱和凝胶电泳法研究了ADM－Fe（Ⅲ）配合物与DNA的结合作用，ADM－Fe（Ⅲ）配合物仍保留了ADM插入结合的特征，并形成一种稳定的DNA－Fe（Ⅲ）－ADM的三元结合物．     

钌（Ⅱ）配合物[Ru（btz）3]2＋和[Ru（btz）（dppz）2]2＋的合成、DNA键合及光断裂研究

本文设计合成了两个含有联噻唑的钌（Ⅱ）配合物[Ru（btz）3]（CIO4）2（1）和[Ru（btz）（dppz）2]（c104）2（2）（btz=4,4’bithiazole,dppz：dipyrido[3,2-a：2’,3’c]phenazine）．通过元素分析、ES-MS、1HNMR和X射线单晶衍射表征了配合物的结构．运用光谱滴定和黏度实验研究了配合物与DNA的作用,发现配合物1与DNA以静电方式结合,配合物2以插入模式与DNA结合．凝胶电泳实验表明配合物1和2在光照射下均可有效断裂DNA,单线杰氢（1O2）和脊某自由墓（OH、县推动断裂反应的活性物种．     

氮杂大环铈(Ⅲ)配合物与pUC19 DNA的相互作用

以一种1,4,7,10,13,16,19,22,25,28,31-十一氮杂2,5,8,11,14,17,20,23,26,29,32-十一酰基-环三十三烷的衍生物（CYC）为配体,在溶液中和Ce（Ⅲ,M）离子形成氮杂大环铈配合物（M-CYC）作为仿生催化剂,通过紫外光谱法、荧光光谱法和凝胶电泳法研究了M-CYC配合物与DNA的相互作用. 结果表明,M-CYC与小牛胸腺DNA（CT DNA）以嵌插方式相互作用,在pH = 8.16的缓冲体系中,其结合常数K_b = 2.0×10⁴ L/mol. 凝胶电泳结果表明,当自由基捕捉剂存在时,M-CYC可将超螺旋pUC19 DNA切割为缺刻型DNA,其切割方式为水解切割.     

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。     

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.     

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^-。     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

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.

     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。     

微量钙的测定方法研究进展

介绍了1995-2006年期间测定微量和痕量钙的方法,如电感耦合等离子体-原子发射光谱法、原子吸收光谱法以及离子色谱法等的工作原理和特点,并说明了其测定微量钙的应用领域。并对微量钙的测定技术进行了展望(引用文献55篇)。     

Stages of thermal decomposition of sodium oxo-salts of sulphur

Thermal behaviour of sodium oxo-salts of sulphur: Na₂SO₄, Na₂S₂O₇, Na₂S₂O₆, Na₂SO₃, Na₂S₂O₅, Na₂S₂O₄, Na₂S₂O₃, Na₂S₃O₆ and of sulphides Na₂S and Na₂S₂ was studied on heating up to 1000°C. The experiments were performed with anhydrous compounds obtained from commercial products by recrystallisation and dehydration. The stage mechanisms of decomposition of anionic sub-lattices of the salts have been proposed basing on the Górski’s morphological classification of simple species. The thermal stability and the stage decomposition mechanisms were correlated with the structure and the potential chemical properties of the salt anions. The thermal decomposition processes were studied by means of thermal analysis, and the decomposition products were identified by means of X-ray phase analysis.