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排序方式: 共有426条查询结果,搜索用时 15 毫秒
1.
M. N. Vidyakin Yu. N. Lazareva Yu. P. Yampolskii A. Yu. Alentiev D. Yu. Likhachev A. L. Rusanov O. V. Kozlova 《Polymer Science Series A》2006,48(6):596-600
The correlation between chemical structure and gas transport properties is considered for a new class of membrane materials based on structurally similar polyphenylquinoxalines that are characterized by different numbers of flexible-O-ether bonds in the repeating unit and different chain rigidities. Permeability, diffusion, and solubility coefficients have been estimated for the gases H2, He, O2, N2, CO, CO2, and CH4; separation factors for various gas pairs have been determined. For the materials with a similar level of cohesive energy density, which characterizes interchain interactions, permeability decreases with a decrease in chain rigidity, whereas selectivity of gas separation increases. 相似文献
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3.
I. L. Glazko O. P. Gur’yanova S. V. Levanova S. A. Kozlova N. S. Neiman 《Russian Journal of Applied Chemistry》2005,78(6):950-954
A procedure was developed for preparing a plasticizer for polyvinyl chloride compounds from the fraction of dioxane alcohols. The main physicochemical properties of the new plasticizer were determined. Items prepared from formulations containing the new plasticizer were fabricated and tested in laboratory.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005, pp. 972–976.Original Russian Text Copyright © 2005 by Glazko, Gur’yanova, Levanova, Kozlova, Neiman. 相似文献
4.
R. K. Chernova L. M. Kozlova E. M. Spiridonova L. V. Burmistrova 《Journal of Analytical Chemistry》2006,61(8):760-766
The main analytical characteristics of the reaction of hexaoxacycloazochrom with lead were determined. A method for the sorption preconcentration of lead on the Thiopan 14 sorbent was proposed. Procedures were developed for the photometric determination of lead in natural waters, air, and soil at the level of the maximum permissible concentration. A new melange gel technique for preparing silicic acid xerogels modified with hexaoxacycloazochrom was developed for the test determination of lead in environmental samples at the level of the maximum permissible concentration. 相似文献
5.
A. V. Zaitsev G. V. Kozlova V. Yu. Borovkov A. Yu. Krylova A. L. Lapidus V. B. Kazanskii 《Russian Chemical Bulletin》1990,39(11):2394-2396
Diffuse scattering IR spectroscopy was used to study the 10% Co/Al2O3 catalyst for the synthesis of aliphatic hydrocarbons from CO and H2. Ionic and metallic cobalt forms were identified in the IR spectroscopy. The adsorption of CO on these forms is accompanied by the appearance of linear and bridged complexes. After prolonged treatment of the catalyst by a CO + 2H2 mixture, the ions and surface of metallic cobalt remain available for the adsorption of CO. Modification of the surface of metallic cobalt occurs upon the action of the reaction medium. This modification is seen in a bathochromic displacement of the IR bands for the adsorbed and linear CO forms. This displacement is accompanied by a reduction in the strength of the metal-carbon bond in the Coo-CO complex.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2640–2643, November, 1990. 相似文献
6.
A. B. Malinin N. V. Kurenkov M. D. Kozlova A. S. Sevastyanova 《Journal of Radioanalytical and Nuclear Chemistry》1988,126(1):17-25
A procedure has been worked out for the preparation of chloroplatinic acid from natural metallic platinum irradiated in a nuclear reactor and purified from199Au impurities by extraction from acidic solutions with ethyl acetate. It was shown that the effective K X-ray activity of natural platinum on irradiation with moderate neutron fluxes /3×1013/ was comparable with that of195mPt obtained from 100%194Pt/with identical neutron fluxes/. Contaminations from193Pt /50 years/ is insignificant and do not produce noticeable radiation loads on the organism on medical tests in vivo. 相似文献
7.
E. Yu. Savonina R. K. Chernova L. M. Kozlova P. S. Fedotov 《Journal of Analytical Chemistry》2005,60(9):874-879
A new approach was proposed to fractionating soil lead species differing in mobility and biological availability. Ground solid samples were retained as a stationary phase in a rotating coiled column while continuously pumping aqueous solutions of salts and complexing agents necessary for the sequential leaching of different element species. It was shown that field-flow fractionation in a rotating coiled column is suitable for separating three lead species in an automatic mode within 4 h, as compared to several days for conventional methods of sequential extraction. The study of lead elution curves at different fractionation steps provides additional information about its mobilization under changing environmental conditions. 相似文献
8.
L. M. Kogan I. V. Kozlova T. M. Filippova E. A. Obol'nikova 《Chemistry of Natural Compounds》1992,28(3-4):321-325
Squalene, 35-methoxyho-6-ene-32R,33R,34S-triol, hop-22(29)-ene, and hopan-22-ol have been isolated fromAcetobacter sp. VSB 917. The structures of the substances isolated and of the 35-methoxyhop-6-ene-32R,33R,34S-triol triacetate obtained have been established by IR, mass, and1H and13C NMR spectroscopies.Vitaminy Scientific-Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 367–372, May–August, 1992. 相似文献
9.
Sokolov MN Gushchin AL Virovets AV Peresypkina EV Kozlova SG Fedin VP 《Inorganic chemistry》2004,43(25):7966-7968
Black single crystals of Ta(4)Se(9)I(8) are obtained in a high yield by heating Ta, Se, and I(2) at 300 degrees C in 1:2.2:1.0 molar ratio. In the structure, the tantalum atoms form a square, with four Se(2) ligands bridging the Ta-Ta edges and one capping the square. Each Ta atom has two terminal iodine atoms. The compound is diamagnetic and has only two electrons for metal-metal bonding. 相似文献
10.
R. K. Chernova L. M. Kozlova I. V. Myznikova Yu. G. Chudnova 《Journal of Analytical Chemistry》2004,59(5):419-423
A method is proposed for the synthesis of silicic acid xerogels based on opoka aluminosilicate (gaize) and silicate glue. The physicochemical properties of xerogels were studied. The complexation of Be(II) with immobilized Chrome Azurol S was studied by electronic absorption and diffuse-reflection spectrometry and solid-phase spectrophotometry. Test procedures were developed for determining Be(II) and Al(III) in waters and soils. 相似文献