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Kostiantyn Kulyk Valentyna Ishchenko Borys Palyanytsya Volodymyr Khylya Mykola Borysenko Tetiana Kulyk 《Journal of mass spectrometry : JMS》2010,45(7):750-761
The interactions between coumarins and the surface of fumed SiO2, CeO2/SiO2, TiO2/SiO2 and Al2O3/SiO2 were assessed by means of temperature‐programed desorption mass spectrometry. The different stages of the thermolysis of coumarin were identified and an analysis of the underlying reactions was performed. The kinetic parameters of the involved reactions were thus obtained. The decomposition of thiazolyl‐substituted coumarins was found to proceed through a ‘thiazole–thiazine’ ring expansion in the adsorbed state. A linear correlation between the sigma constants (Σσ) of the coumarin substituents and the activation energy of CO2 formation was obtained. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Two different approaches to the synthesis of 1-unsubstituted 5-cinnamoyl-3,4-dihydropyrimidine-2(1H)-ones have been developed. The first includes N(1)-protection of the starting 5-acetyl-3,4-dihydropyrimidine-2(1H)-one, further Claisen–Schmidt reaction, and cleavage of the protecting group. The second approach consists of one-pot condensation of urea, aldehyde, and cinnamoylacetone as dicarbonyl component. The 5-cinnamoylderivative synthesis starting from 5-acetyl-1,3-dialkyl-3,4-dihydropyrimidine-2(1H)-ones is also shown. 相似文献
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We propose an integral form of the Green function for homogeneous linear extensions of dynamical systems in the case of the existence of their solutions bounded with respect to normal coordinates.__________Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 57, No. 1, pp. 84–93, January, 2005. 相似文献
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We study the problem of the existence of a Green-Samoilenko function for some linear extensions of dynamical systems.__________Translated from Neliniini Kolyvannya, Vol. 7, No. 4, pp. 468–474, October–December, 2004. 相似文献
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Synthetic mixtures of aliphatic and aromatic ethers, satmated fatty acids, and substituted benzenes and naphthalenes were separated by elution through columns of ion-exchange resins with aqueous solutions of acetic acid as eluent An attempt was made to use a resin of low capacity for the separation of such mixtures, and the results of this attempt are used to help elucidate the theory of solubilization chromatography 相似文献
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