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91.
The algebraic structure of chiral anomalies is made globally valid on non-trivial bundles by the introduction of a fixed background connection. Some of the techniques used in the study of the anomaly are improved or generalized, including a systematic way of generating towers of descent equations.This work was supported in part by the Director, Office of Energy Research, Office of High Energy and Nuclear Physics, Division of High Energy Physics of the U.S. Department of Energy under contract DE-AC03-76SF00098 and in part by the National Science Foundation under research grant PHY81-18547 相似文献
92.
Verdejo B Aguilar J Doménech A Miranda C Navarro P Jiménez HR Soriano C García-España E 《Chemical communications (Cambridge, England)》2005,(24):3086-3088
L-glutamate and L-aspartate selectivity is achieved by the action of two Cu2+ metal ions rightly disposed in a cyclophane-type macrocyclic framework; electrochemical sensing of glutamate has been achieved by adsorption of the copper complexes on graphite electrodes. 相似文献
93.
Fang Xin FU Xiu Juan LI Hua De PAN Department of Chemistry. Northeast Normal University. Changchun Yan XING Yong Hua LIN Changchun Applied Chemistry Institute Academy Sinica. Changchun 《中国化学快报》1995,(1)
CRYSTALANDMOLECULARSTRUCTUREOFTHECOMPLEXOFMETHOXYCARBONYLETHYLTINTRICHLORIDEWITHSALICYLIDENE-M-TOLUIDINEFangXinFU;XiuJuanLI;H... 相似文献
94.
A capillary zone electrophoresis (CZE) method with ultraviolet-visible detection has been established and validated for the determination of five phenothiazines: thiazinamium methylsulfate, promazine hydrochloride, chlorpromazine hydrochloride, thioridazine hydrochloride, and promethazine hydrochloride in human urine. Optimum separation was obtained on a 64.5 cm x 75 microm bubble cell capillary using a buffer containing 150 mM tris(hydroxymethyl)aminomethane and 25% acetonitrile at pH 8.2, with temperature and voltage of 25 degrees C and 20 kV, respectively. Naphazoline hydrochloride was used as an internal standard. Field-amplified sample injection (FASI) has been applied to improve the sensitivity of the detection. Considering the influence of parameters affecting the on-line preconcentration (nature of preinjection plug, sample solvent composition, injection times, and injection voltage) and due to the significant interactions among them, in this paper we propose for the first time the application of a multivariate approach to carry out the study. The optimized conditions were as follows: preinjection plug of water for 7 s at 50 mbar, electrokinetic injection for 40 s at 6.2 kV, and 32 microm of H3PO4 in the sample solvent. Also, a solid-phase extraction (SPE) procedure is developed to obtain low detection limits and an adequate selectivity for urine samples. The combination of SPE and FASI-CZE-UV allows adequate linearities and recoveries, low detection limits (from 2 to 5 ng/mL), and satisfactory precisions (3.0-7.2% for an intermediate RSD %). 相似文献
95.
Jorge A. R. Alarcon A. T. Soldatenkov S. A. Soldatova Alicia U. Samalloa Juan U. Obando N. S. Prostakov 《Chemistry of Heterocyclic Compounds》1993,29(9):1054-1058
2,3,8,9-Tetramethoxy-11-phenyldibenz[2,3;7,8]indolizine was obtainedinhighyieldfrom (6,7-dimethoxyisoquinolin-1-yl)-(3,4-dimethylphenyl)phenylcarbinol by cyclization in the presence of formic acid. The behavior of (6,7-dimethoxyisoquinolin-1-yl)-(3,4-dimethoxyphenyl)methylcarbinol and (6,7-dimethoxyisoquinolin-1-yl-(3,4-dimethoxyphenyl)carbinol was studied under these same conditions. 2,3,7,8-Tetramethoxy-11-phenyl-5,6-dihydrodibenz[2,3;7,8]indolizine was obtained by hydrogenation on rhenium heptasulfide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1233–1238, September, 1993. 相似文献
96.
97.
倒数示波计时电位法在合金样品测定中的应用 总被引:2,自引:0,他引:2
应用倒数示波计时电位法,在含有吸附络合物的溶液中,采用桂汞电极作为极化电极,测定了Cu^2+、Ni^2+、Cd^2+、Pb^2+等几种金属离子的检测下限,并通过沿(dE/dt)-1 ̄E曲线上的峰高对合金样品进行定量分析,得到满意结果。实现了示波分析由常量到微量的飞跃。 相似文献
98.
Juan Primera Anwar Hasmy Thierry Woignier 《Journal of Sol-Gel Science and Technology》2003,26(1-3):671-675
We introduce a new numerical technique for the calculation of the pore size distribution in two-dimensional disordered systems. Our method is based on a triangulation technique which allows a closer measurement of pores surface without any morphological hypothesis.In this work, we focus our calculations in simulated gels. Such materials are modeled in two different conditions: by means of the Diffusion-Limited and Reaction-Limited Cluster-cluster Aggregation algorithms, DLCA and RLCA, respectively. In both situations, when the particles concentration decreases, the average pores size increases. The more compact cluster in RLCA, compared with DLCA, is consistent with the pore size distribution we have calculated. The simulated mean pore size is quantitatively in agreement with experimental data from literature. 相似文献
99.
100.
Densities of boldine + alcohol binary mixtures were measured over the whole accessible range of boldine compositions at temperatures from 283.15 to 333.15 K using an Anton-Paar digital vibrating glass tube densimeter. The binary systems studied include, as a solvent, seven normal alcohols from n-C1 to n-C6, n-C8, and isopropanol. The density of these systems has been found an increasing function of the boldine composition. A new methodology based on density data of solutions of solid solutes with normal alcohols is described in order to determine solid molar volume of pure solutes. This methodology was validated with pure solid naphthalene molar volumes data at 298.15 K, with an average uncertainty of 6%. 相似文献