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Simple separation of carbazole and anthracene from monosubstituted anthraquinones is achieved through the application of the zone-melting technique used biphenyl as a medium. Determination limits for both compounds measured by synchronous fluorimetry are 2 μg g?1 in 2-methyl-, 2-ethyl-, 1-hydroxy- and 1-chloroanthraquinones, and 10 μg g?1 in another four derivatives. 相似文献
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This study deals with the development of the approximate method to analyze the sound field around equally spaced finite obstacles, using the periodic boundary condition. First, on the assumption that the equally spaced finite obstacles are the periodically arranged obstacles, the sound field is analyzed by boundary integral equation method with a Green’s function which satisfies the periodic boundary condition. Furthermore, by comparing these results and the exact solution by using the fundamental solution as Green’s function, the validity of the approximate method is also investigated. Next, in order to evaluate the applicability of the approximate method, the simple formula using some parameters, i.e., the frequency, the period, and the number of obstacles, etc., is proposed. The results of the sound field analysis applied the formula are presented. 相似文献
138.
8-Hydroxyquinoline derivative 1 as a fluorescent chemosensor for Zn2+ was synthesized. Because Cd2+ is often found with Zn2+ in the environment and can form fluorescent complexes with chelating fluorophores, a potentially important property of chemosensors for Zn2+ is their selectivity for Zn2+ over Cd2+. The Zn2+ or Cd2+ complexes of 1 gave an emission band from the 1:1 complex, but the fluorescence intensity for Cd2+ was a half of that for Zn2+. Ligand 1 is suited for use as a fluorescent chemosensor for Zn2+. 相似文献
139.
T Yamakawa H Matsukura Y Nomura M Yoshioka M Masaki H Harada S Okabe 《Chemical & pharmaceutical bulletin》1992,40(3):675-682
A series of 2-[(2-imidazolylsulfinyl)methyl]anilines (2) having various substituents on their imidazole and aniline rings was synthesized and examined for their H+/K(+)-ATPase (adenosine triphosphatase) inhibitory effects and antisecretory activity against histamine-stimulated gastric acid secretions in Heidenhain pouch dogs. Although substitutions on the imidazole ring did not enhance biological activity, substitutions on the aniline ring by electron-donating substituents potently enhanced the enzyme inhibitory activity and also showed an inhibitory effect on histamine-stimulated gastric acid secretion after oral administration. In particular, the in vitro activity of the dimethyl (2u--w) and trimethyl (2ac) derivatives was about 10 times that of omeprazole. Also, 4-methyl (2k), 4-methoxy-5-methyl (2y) and 3,5-dimethyl-4-methoxy (2ab) derivatives showed a potent antisecretory effect of more than 80% after oral administration at 6 mg/kg. Although these aniline derivatives have relatively low stabilities in aqueous solution, replacement of the isobutyl group at the aniline nitrogen atom with N-(2-methoxyethyl) group enhanced the stability. 相似文献
140.
Masaki Hibino 《Journal of Differential Equations》2006,227(2):499-533
This article part I and the forthcoming part II are concerned with the study of the Borel summability of divergent power series solutions for singular first-order linear partial differential equations of nilpotent type. Under one restriction on equations, we can divide them into two classes. In this part I, we deal with the one class and obtain the conditions under which divergent solutions are Borel summable. (The other class will be studied in part II.) In order to assure the Borel summability of divergent solutions, global analytic continuation properties for coefficients are required despite of the fact that the domain of the Borel sum is local. 相似文献