Ein alternativer Weg zur Darstellung von Bi2Sr2CaCu2Ox,YBa2Cu3O7−δ, und YBa2Cu3−xMxO7−δ (M  Ni,Ag und x ≤ 33 Mol%)

An Alternative Method for Preparation of Bi₂Sr₂CaCu₃O_x, YBa₂Cu₃O_7?δ, and YBa₂Cu_3?xM_xO_7?δ (M ? Ni, Ag and x ≤ 33 Mol%) Oxidation of quenched melts of metals in a well defined argon/oxygen atmosphere has been found as an alternative method to prepare hight purity samples of Bi₂Sr₂CaCu₂O_x without Pb-stabilization. A special equipment for the oxidation of powder samples will be described. By our new method it is also possible to prepare YBa₂Cu₃O_7?δ and derivatives of this compound, where Cu is substituted by high amounts of Ni or Ag.     

(S2W(μ-S)2OW(μ-S)2WS2]2-的合成和性质研究

本文提出在酸性水溶液中,合成钨硫原子簇状化合物[(n-Bu)_4N]_2[S_2W(μ-S)_2OW(μ-S)_2WS_2]和的新方法,并进行了化学分析和红外光谱、电子光谱的测定。     

原子发射光谱法间接测定烟碱的研究

本文提出了测定烟碱的间接原子发射光谱分析新方法。根据在盐酸介质中，烟碱被质子化后能与雷氏铵盐定量形成难溶化合物的性质，将沉淀溶解后，用原子发射光谱法测定铬来间接测定烟碱的含是。实验中研究了沉淀反应的最佳酸度、雷氏铵盐用量及放置时间等条件，选择了最佳的沉淀溶解剂，考查了共存离子的影响及方法的回收率和精密度。用本法测定了烟叶和香烟样品中的烟碱的含量，结果与光度法比较一致。方法的相对标准偏差为３．１６％     

Acetyl chloride-3,5-di(tert-butyl)-4-hydroxy-N,N-dimethylbenzylamme salt in the benzylation of organic and inorganic sulfur-containing compounds

The reactions of the quaternary acylammonium salt formed on treatment of3,5-di-tertbutyl-4-hydroxy N,N-dimethylbenzylamine with acetyl chloride, with various organic and inorganic sulfur-containing compounds were studied. The possibility of using this salt for the introduction of a sterically hindered phenol moiety in various sulfur-containing compounds was shown.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 98–102, January, 1994.     

Imparting durable antimicrobial properties to cotton fabrics using quaternary ammonium salts through 4-aminobenzenesulfonic acid-chloro-triazine adduct

A 4-aminobenzenesulfonic acid-chloro-triazine adduct was successfully synthesized in a laboratory scale and treated with cotton fabrics in order to increase the anionic sites and thereby % exhaustion of cationic compounds. Two Quaternary Ammonium Salts (QAS) was investigated namely, Cetylpyridinum chloride (CPC) and Benzyldimethylhexadecyl ammonium chloride (BDHAC) which are widely accepted as strong antimicrobial agents. The reaction mechanism involved in the synthesis of the reactive adduct as well its application to cotton fabric were demonstrated in detail. The effects of application parameters, namely pH, temperature and liquor ratio were examined. The reaction efficiency was determined through monitored % exhaustion of the adduct by cotton fabric. Antimicrobial activity of the treated cotton sample was studied against Staphylococcus aureus according to AATCC test method 100-1999. Results obtained show that the treated fabric shows higher antimicrobial activity compared with the untreated fabric. The results depict also that % exhaustion decreases as the pH, temperature and liquor ratio increase. Moreover, the appropriate predictable empirical models were developed using Excel solver function incorporating interaction effects of all variables to predict the % exhaustion and the satisfactory results (R² > 0.98) were obtained.     

Reindarstellung von Neodymoxid in großem Maßstab durch fraktionierte Kristallisation der Ammoniumdoppelnitrate

Summary Rare earth ammonium nitrates containing 125 kg neodym oxide of about 86% purity were separated by fractional crystallization yielding 83.1 kg Nd-oxide (98–99%) in form of its double nitrate. 20 kg of it were further crystallized: after 138 rows there resulted 15 kg Nd₂O₃ of 99.9% purity. The effective separation factors were determined.

     

Separation and determination of metals as complexes of 1-nitroso-2-naphthol-6-suiphonic and 2-nitroso-1-naphthol-6-sulphonic acids. II. Liquid chromatography on c18 bonded and copolymer stationary phases

An ion-pair Chromatographic system for the separation of copper(II), palladium(II), iron(III) and cobalt(III) as ion-associates of their l-nitroso-2-naphthol-6-sulphonate and 2-nitroso-l-naphthol-6-sulphonate anionic complexes with organic ammonium compounds and inorganic cations has been studied. Isocratic and gradient elution methods were used, and the effects of column material, organic and aqueous modifiers, and pH of the eluent on the retention were examined. The elution time for the metal complex anions depends on the eluent, the proportion of organic solvent in the mobile phase, the pH of the eluent and the extraction coefficient of the compounds. The compounds were identified photometrically with a diode-array detector at wavelengths of 229, 254, 260, 298, 320 and 400 nm. The detection limits for the metals are at the ng/ml level.     

Amino acid binding by 2-(guanidiniocarbonyl)pyridines in aqueous solvents: a comparative binding study correlating complex stability with stereoelectronic factors

A series of guanidiniocarbonylpyridine receptors has been synthesized, and these compounds bind amino acids (carboxylate forms) in aqueous DMSO with association constants ranging from K = 30 to 460 M(-1) as determined by NMR titration experiments. The differences in the complex stabilities can be correlated with steric and electrostatic effects with the aid of calculated complex structures. For example, the electrostatic repulsion between the pyridine nitrogen lone pair and the bound carboxylate makes anion binding less efficient than with the analogous pyrrole receptors previously introduced by us for carboxylate binding in water. Furthermore, steric interactions between the receptor side chain as in 2 b and the bound substrate also disfavor complexation.     

表面富集季胺盐的交联聚苯乙烯微球合成与表征及其溶胀行为研究

在聚合物微球表面引入不同的基团 (如亲水性的羟基或羧基 ) ,可以改善聚合物微球的稳定性甚至生物相容性[1～ 4] ;利用表面基团可以把无机半导体微粒和功能有机分子以及生物分子引入聚合物微球[5～ 8] ,赋予聚合物微球特殊的性能 ,使其广泛应用于涂料、光电功能材料和生物医用材料等领域[9～ 15] .其中 ,表面带有阳离子的聚合物微球在絮凝剂、胶粘剂、水性涂料等方面已经得到广泛研究[16～ 2 0 ] .通常阳离子聚合物微球可以根据不同的需要利用常规乳液聚合、核壳乳液聚合等方法来合成 .亲水性和疏水性单体进行的无皂乳液聚合[2 1] ,因其能在…