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991.
N. A. Anisimova G. A. Berkova T. Ya. Paperno L. I. Deiko 《Russian Journal of General Chemistry》2002,72(3):460-463
Thermal decomposition of substituted 1- and 2-pyrazolines was used to obtain cyclopropane derivatives of aspartic and adipic acids. 相似文献
992.
M. C. Mahedero A. Muñoz De La Peña A. Bautista J.J. Aaron 《Journal of inclusion phenomena and macrocyclic chemistry》2002,42(1-2):61-70
The effect of -cyclodextrin (-CD) and hydroxypropyl--cyclodextrin (HP--CD) upon the photochemically-induced fluorescence (PIF) properties of four phenylurea herbicides, including linuron, diuron, isoproturon and neburon has been studied. Photochemical conversion of these nonfluorescent herbicides into strongly fluorescent photoproducts was shown to occur in -CD and HP--CD aqueous media. The influence of pH, UV irradiation time and photoproduct stability on the fluorescence intensity was also investigated. In addition, the stoichiometry and formation constants of the complexes formed between herbicides and -cyclodextrin (-CD) or 2-hydroxypropyl--cyclodextrin (HP--CD) were determined. The formation constant values, ranging from 184 ± 40 to 1498 ± 245 M-1, were calculated by applying the iterative nonlinear regression (NLR) approach to the PIF data. Linear calibrations graphs were established in the interval 1–12 g/mL, for diuron, linuron and neburon. The IUPAC limits of detection ranged between 580 and 700 ng/mL, according to the compound. Application to the analysis of phenylurea herbicides in spiked river water was also described. 相似文献
993.
Ya. V. Rashkes Z. Sh. Faizutdinova I. A. Bessonova S. Yu. Yunusov 《Chemistry of Natural Compounds》1973,6(5):593-597
Conclusions The Claisen rearrangement of bucharaine and of the aldehyde bucharainal takes place under the conditions of mass spectrometry. At low temperatures inversion predominates and at high temperatures the anomalous rearrangement.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 577–583, September–October, 1970. 相似文献
994.
N. V. Grishatova V. F. Ur’yash A. E. Gruzdeva N. V. Novoselova 《Russian Journal of Applied Chemistry》2006,79(12):1930-1934
The enthalpy of hydrolysis of potato starch and some starch-containing components of Lider-1 nutrition product for enteral (tube) feeding in the presence of α-amylase enzyme was studied on a DAK-1-1 differential microcalorimeter. 相似文献
995.
B. A. Vigante M. I. Terekhova Ya. Ya. Ozols E. S. Petrov G. Ya. Dubur 《Chemistry of Heterocyclic Compounds》1989,25(9):1028-1031
The patterns governing the dependence of NH-acidity on the presence of -, - and -substituents in the 1,4-dihydropyridine ring and on their nature have been established by comparison of the pKa values of monocyclic 1,4-dihydropyridines and 4,5-dihydroindenopyridines. Additional data were obtained on the influence of the the electronic effects of sulfur-containing substitutents on the reaction center in the dihydropyridine molecules.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1228–1231, September, 1989. 相似文献
996.
The results of studies on the synthesis of defect magnesium oxides by MgO hydration in salt solutions are summarized. The incorporation of oxygen-containing salt anions into the anionic hydroxide/oxide framework is described. In this case, the anion residue whose oxygen atoms belong to the oxygen framework of the oxide is incorporated in the octahedral oxygen cell of the oxide to occupy the place of a virtual magnesium cation. A portion of cationic vacancies remains free, whereas a portion is occupied by the transformed anion residue with a positive charge other than 2+. As a result, defect magnesium oxides are formed as substitutional solid solutions. The structure and charge heterogeneity of defect oxides is responsible for their high catalytic activity. 相似文献
997.
The concepts of the selective inhibition of reactions with the participation of HO
2· radicals by nitrobenzene in accordance with a cyclic mechanism were supported using cyclohexanol oxidation as an example. It was demonstrated that the nitroxyl radical generated from nitrobenzene selectively reacts with HO2
·
to form hydrogen peroxide and nitrobenzene. A decrease in the rates of oxidation of esters, carboxylic acids, and ketones with specially chosen structures in the presence of nitrobenzene, as well as the detection of H2O2 and corresponding ,-unsaturated compounds among the reaction products, indicated that the degradation of -peroxyl radicals of the above compounds occurred under conditions of the liquid-phase oxidation of organic substances that result in the formation of the HO2· radical and an unsaturated compound.Translated from Kinetika i Kataliz, Vol. 45, No. 6, 2004, pp. 814–820.Original Russian Text Copyright © 2004 by Nepomnyashchikh, Nosacheva, Perkel. 相似文献
998.
Lampeka Ya. D. Manorik P. A. Pogorelaya L. M. Prikhod'ko A. I. 《Theoretical and Experimental Chemistry》2002,38(5):342-346
The interaction of mono- and oligomacromolecular complexes of copper(II) and nickel(II) with water vapor has been studied on a piezoquartz microbalance. It has been established that the effectiveness of adsorption is determined by the nature of the metal ion to a larger extent than the quantity of macrocyclic ligand in the receptor molecule. Oligomacrocyclic complexes of copper(II) are shown to have prospects for use as active coverings of moisture meters working over a wide range of relative humidity. 相似文献
999.
K. M. Efimov G. A. Grigor’ev P. A. Gembitskii N. A. Polikarpov N. V. Alov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(2):291-293
Using X-ray photoelectron spectroscopy, it was found that the treatment of aluminum, nickel, and ceramic surfaces with a 1% Biopag aqueous solution (Biopag, poly(hexamethylene guanidine chloride)), was synthesized at the Institute of Ecological and Technological Problems in accordance with TU (Specifications) 9392-020-41547288-02) results in the formation of thin polymer films on the surfaces. The chemical composition of the films was determined. It was shown that the chemical composition of the films is changed on long standing in air. Microbiological tests were carried out, and the minimum suppressing concentration toward Pseudomonas aeruginosa was determined. It was shown that the Biopag films aged for 6 months retain up to 84% of their initial activity. 相似文献
1000.
A. Ya. Samuilov L. A. Zenitova S. E. Solov'eva Ya. D. Samuilov 《Russian Journal of Applied Chemistry》2005,78(7):1115-1118
The composition of oligoethers that are components of Laprol-373 and of products of their reaction with 2,4-toluylene diisocyanate were studied by matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF). 相似文献