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961.
Allen I. Cohen
Louis Gordon
《Talanta》1961,7(3-4):195-211Studies have been made of the distribution behaviour of tracers with alkaline earth sulphates, using the technique of precipitation from homogeneous solution. The co-precipitation of strontium with barium sulphate and of lead, lanthanum, and yttrium, separately, with barium sulphate, and with strontium sulphate, were investigated. Although there was qualitative correlation between the observed values of the distribution coefficient and the theoretical solubility product ratios for each of the binary systems studied, the divergence between theory and observation was so great that it seems unlikely that there is any quantitative correlation. 相似文献
962.
Podberezskaya N. V. Batsanova L. R. Egorova L. S. 《Journal of Structural Chemistry》1965,6(6):815-818
Journal of Structural Chemistry - 相似文献
963.
Evolution of Statistical Ensembles of Microdomains on the Surface of Films of Rigid-Chain Polyimide during Thermal Imidization 总被引:1,自引:0,他引:1
Bronnikov S. V. Sukhanova T. E. Goikhman M. Ya. 《Russian Journal of Applied Chemistry》2003,76(6):967-971
Statistical ensembles of microdomains formed on the surface of polyimide films based on pyromellitic dianhydride and 2,7-diaminofluorene during thermal imidization were described in terms of the model of reversible aggregation using the electron-microscopic data. Parameters of the statistical distribution were determined for each ensemble depending on the film heating temperature. 相似文献
964.
Kopeikin V. V. Valueva S. V. Kipper A. I. Filippov A. P. Khlebosolova E. N. Borovikova L. N. Lavrent'ev V. K. 《Russian Journal of Applied Chemistry》2003,76(5):818-821
The nanostructures formed by reduction of Se(IV) in the selenite-ascorbate redox system in an aqueous solution of supermacromolecular polycation, poly[trimethyl(methacryloyloxyethyl)ammonium] methyl sulfate, were studied by static and dynamic optical scattering and flow birefringence. 相似文献
965.
Deprotonation of 1,2-C(70)H(2) with TBAOH, followed by alkylation with methyl bromoacetate, results in formation of a C1-monoalkylated 1,2-dihydro-C(70) derivative. The position of the alkyl group (C1) was established by NMR spectroscopy and comparison with literature spectra of C2-monoalkylated analogs. Presumably, C1-alkylation is the major process due to selective deprotonation of 1,2-C(70)H(2) at C1. Substitution of benzyl bromide for methyl bromoacetate results in rapid dialkylation, unless the amount of base is carefully controlled, in which case C1-monobenzylation is the major process. This methodology for alkylation at C1 is complimentary to methods for the C2-monoalkylation of C(70) with Zn and methyl bromoacetate. 相似文献
966.
M. I. Rozengart V. L. Polinin V. G. Bryukhanov B. A. Kazanskii 《Russian Chemical Bulletin》1973,22(7):1635-1636
Conclusions In the dehydrocyclization of n-octane the m- and p-xylenes are formed as a result of the isomerization of the carbon skeleton of the aliphatic intermediate products of the reaction, namely the octadienes and octatrienes.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1675–1676, July, 1973. 相似文献
967.
Rakhimov A. I. Nalesnaya A. V. Fedunov R. G. Vostrikova O. V. 《Russian Journal of General Chemistry》2004,74(5):799-800
Russian Journal of General Chemistry - 相似文献
968.
Claisen-Schmidt condensation of 4-hydroxy-3-acetyl-6-methylpyrid-2-one, and its N-methyl and N-phenyl derivatives with aromatic aldehydes is investigated, and it is shown that the products of this reaction are 3-cinnamoyl and not 6-styryl derivatives. 相似文献
969.
970.
The regularities of the formation of diffusion boundary layers during the transport of aliphatic acids in electromembrane systems are studied and their characteristics obtained experimentally are analyzed. It is shown that their concentration profiles in solutions of the electrodialyzer sections are asymmetric near membranes of different polarity. Experimental values of diffusion layer thicknesses are compared with those following from the known theoretical relations. The equation, which is proposed for the surface concentration, permits the prediction of the operation mode of apparatus during electrodialysis of solutions of aliphatic acids and other weak electrolytes. Specific features characterizing the emergence of a limiting state and the character of the distribution of limiting current densities over the height of the membrane channel are revealed. 相似文献