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2.
L. Yu. Novoselova E. E. Sirotkina E. V. Sergeeva 《Russian Journal of Applied Chemistry》2006,79(3):372-376
The possibility of raising the static exchange capacity of strongly acidic ion-exchange materials produced by grafting of styrene onto polypropylene fibers, with the subsequent sulfonation of the products synthesized, was analyzed. The chemical and osmotic stabilities of the sulfonic cation exchangers obtained and their frost resistance in freeze-thaw cycles were studied. 相似文献
3.
It is experimentally found that UV irradiation of 10-m polytetrafluoroethylene films electrified in a negative corona discharge produces a transient current which is unipolar and whose peak value decreases in successive exposures. A model is considered on the basis of spatial impurity-center photoionization and the resultant positive-carrier motion, excluding recapture and recombination, in the strong internal field generated by trapped negative charges. Correlation of the experimental and calculated photocurrent kinetics yield values for the hole mobility (8.9×10–15 m2·V–1·sec–1) and impurity-center concentration (1.5×1018 m–3).Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 26–29, June, 1990. 相似文献
4.
Conclusions Primary amino alcohols react with CO in the presence of mercuric acetate at 100–200° and a pressure of 100–150 atm to give the corresponding N-(hydroxyalkyl)formamides in a yield of 1.4–2.5 M/M of reacted Hg(OCOCH2)3. Morpholine under analogous conditions forms the corresponding formyl derivative and the urea derivative in a 1.2–51 ratio, while cyclohexylamine forms the same derivatives in an 0.7 1 ratio.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1533–1536, July, 1973. 相似文献
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Alexander S GolubevNatalia N Sergeeva Lothar HennigAlexey F Kolomiets Klaus Burger 《Tetrahedron》2003,59(9):1389-1394
An efficient synthesis of trifluoromethyl-containing 2,3-allenols via carbonyl-yne reaction of 3,3,3-trifluoropyruvates with acetylenes is described. In the presence of MgBr2·Et2O the reaction of methyl trifluoropyruvate with hex-1-yne proceeds diastereoselectively. Trifluoromethyl-substituted 2,3-allenols can be stereoselectively transformed into trifluoromethyl-substituted 2,5-dihydrofurans on treatment with AgNO3. 相似文献
7.
Natalia N. Sergeeva 《Tetrahedron》2007,63(50):12454-12464
Hydroporphyrins have been synthesized using both Pd-catalyzed and non-catalyzed approaches. Comparative studies of the reaction of tetrasubstituted porphyrins with organolithium reagents in the presence of and without palladium catalysts showed that depending on reagents, the catalyst structure and reactivity of the corresponding porphyrins, chlorins (β-hydroporphyrins) and/or porphodimethenes (meso hydroporphyrins) of 5,10-type can be prepared in reasonable yields. In the absence of Pd catalysts, the formation of chlorins is predominant in the reactions with aliphatic RLi while porphodimethenes are the main products in reactions with PhLi. The use of a palladium catalyst resulted in the formation of both types of hydroporphyrins and the selective formation of either β-mono- or disubstituted chlorins. Of special interest was the reaction of octaethylporphyrin. Here, reaction with t-BuLi in the presence of Pd(PPh3)4/CuI proceeded with complete regioselectivity for 5,10-porphodimethenes. 相似文献
8.
A.K. Kazansky L. Yu Sergeeva 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1996,37(4):305-313
The method of an accurate calculation of vibrational excitation cross sections of a two-mode molecule by slow electrons within the framework of the local theory (the ‘boomerang’ model) is applied for a model study of the excitation of the symmetrical stretching vibrational modes of carbon dioxide in the two-mode approximation (i.e., only the symmetrical stretch and bending modes are included in the consideration). It is shown that the 'boomerang’ oscillations in the cross section are strongly suppressed due to the decay of the one-dimensional ‘boomerang' state caused by the anion wave packet sliding from the linear configuration ridge. Consequently, the bending motion in CO2 molecule should to be taken into account even if only the processes without the final bending excitation are considered. A simple quasi one-dimensional model describing the system sliding from the ridge is put forward which treats this phenomenon as a decay of the initial wave packet via the series of diabatic resonant states related to unstable trajectory. 相似文献
9.
Safiullina T. R. Sergeeva E. A. Sopin V. F. Zenitova L. A. 《Russian Journal of Applied Chemistry》2002,75(6):1001-1005
Physicochemical properties of castable polyurethanes based on polyethylene glycol adipate and mixture of 2,4- and 2,6-toluylene diisocyanate (NCO : OH molar ratio 1.6) and filled to 10 wt % with silica gel (waste from petrochemical production) were studied. 相似文献
10.
L. N. Sobenina A. I. Mikhaleva M. P. Sergeeva D. -S. D. Toryashchinova O. B. Kozyreva B. A. Trofimov 《Chemistry of Heterocyclic Compounds》1996,32(1):43-47
Condensation of pyrrole-2-dithiocarboxylates with CH acids containing ester groups, in the KOH-DMSO system, was used to prepare previously unknown 1-alkylthio-3H pyrrolizin-3-ones. The latter, treated with secondary amines, are readily converted to the corresponding 1-amino derivatives. 相似文献