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991.
S. V. Lev R. P. Zakirova Z. Saatov M. V. Gorovits N. K. Abubakirov 《Chemistry of Natural Compounds》1990,26(1):40-41
The possibility has been studied of obtaining ecdysteroids — ecdysterone and turkesterone — with the aid of a culture of the tissues and cells of the plantAjuga turkestanica. Conditions have been selected under which the yield of ecdysteroids in the culture of tissues and cells is comparable with amounts of the same substances in the organs of the whole plant.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 51–52, January–February, 1990. 相似文献
992.
M. O. Lozinskii Yu. A. Fialkov V. S. Khomenko T. A. Pavich 《Theoretical and Experimental Chemistry》1990,26(2):228-231
A series of new adducts of fluorinated REE -diketonates with triphenylphosphine oxide was synthesized. The paths of their fragmentation under electron impact were investigated. It was shown that in contrast to the complex with 1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dione, the complexes of europium with 1-trifluoromethoxy-1,1-difluoro-5,5-dimethylhexane-2,4-dione and 1, 1,1-trifluoro-5,5-dimethylhexane-2,4-dione form dimeric associates in the gaseous phase. The reasons for this difference in the behavior of the complexes and the possible structure of one of the dimers are discussed.Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 26, No. 2, March–April, 1990. 相似文献
993.
994.
V. A. Vinokurov Yu. N. Polivin M. A. Silin E. A. Ageev M. A. Zatikyan R. A. Karakhanov 《Russian Chemical Bulletin》1989,38(9):1984-1984
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2154–2155, September, 1989. 相似文献
995.
996.
997.
T. Yu. Samgina P. A. Sharbatyan L. S. Shishkanova N. A. Andronova A. I. Pavlyuchenko V. V. Titov 《Chemistry of Heterocyclic Compounds》1987,23(11):1207-1211
The basic principles of the mass-spectral fragmentation of arylalkylpyridines that contain substituents in various positions were established. The principle ions that can be used in Chromatographic mass-fragmentographic analysis in the study of liquid-crystal compositions were determined for each specific case.Communication 1 of the series Mass spectra of liquid crystalsTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1509–1513, November, 1987. 相似文献
998.
V. A. Kaganovskii A. S. Plachinda V. M. Chertov L. V. Baksheev V. I. Khromov 《Theoretical and Experimental Chemistry》1987,23(5):596-600
Mössbauer spectroscopy and x-ray phase analysis have been used to examine the structural states and grain sizes of the iron-bearing phase in ferrosilica gels in the initial state and after hydrothermal treatment at 673 K. The component ratio has a substantial effect on the phase composition. The specific surface is also related to the phase composition.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 5, pp. 647–651, September–October, 1987. 相似文献
999.
V. G. Kokacheva L. V. Menshikova S. K. Talitskikh P. G. Khalatur 《Journal of Structural Chemistry》1995,36(5):734-738
A system of Ornstein-Zernike integral equations is solved numerically to determine the heats of vaporization ΔHV of liquid ethane, propane, and n-butane. It is shown that the calculations (the deformations of valence bonds and bond angles
in the liquid-phase molecules are ignored) give rather accurate values of ΔHV, which are in agreement with the corresponding experimental data. On the other hand, it is established that if there are
intramolecular rotational degrees of freedom, ΔHV depends on the angle of internal rotation ϕ. The function ΔHV(ϕ) is minimum for trans-conformations (ϕ=0) and maximum for cis-conformations (ϕ=180°). Hence, intermolecular interactions
stabilize compact (convolute) conformations. The energy of this effect is of the order of 1 kJ/mole.
Tver State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 5, pp. 808–813, September–October, 1995.
Translated by I. Izvekova 相似文献
1000.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 184–185, January, 1994. 相似文献