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Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account to the Löwdin prucedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of 15c and 12c bands) and the inverse dependence on the magnitude of the spin-orbit splitting is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semicondactors, except for materials with very strong nonparabolicity of the band of silicon type.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 66–70, February, 1987. 相似文献
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Zh. M. Putieva L. G. Mzhel'skaya T. T. Gorovits E. S. Kondratenko N. K. Abubakirov 《Chemistry of Natural Compounds》1976,11(6):756-761
Summary Alternative structures for the acyloside chain of acanthophylloside B and C have been established.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 728–734, November–December, 1975. 相似文献
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L. M. Khalilov L. A. Baltina L. V. Spirikhin E. V. Vasil'eva R. M. Kondratenko A. A. Panasenko G. A. Tolstikov 《Chemistry of Natural Compounds》1990,25(4):426-430
Details of the13C NMR spectra of glycyrrhizic acid and four of its derivatives are given, and on their basis the configurations of the anomeric centers of the carbohydrate chain have been redetermined and the -configuration of the C-1 carbon atom has been suggested.Institute of Chemistry, Bashkir Scientific Center, Urals Branch, USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 500–505, July–August, 1989. 相似文献
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V. I. Grishkovets A. E. Kondratenko N. V. Tolkacheva A. S. Shashkov V. Ya. Chirva 《Chemistry of Natural Compounds》1995,30(6):689-692
The leaves of common ivy have yielded 11 triterpene glycosides: the 3-O--L-pyranosides of oleanolic acid (1), of echinocystic acid (2), and of hederagenin; the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside]s of oleanolic acid (4), of echinocystic acid (5), and of hederagenin (6); the O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl ester of hederagenin 3-O--L-pyranoside (7); the O--D-glucopyranosyl-(16)-O--D-glucopyranosyl ester of hederagenin 3-O-[O--L-pyranosyl-(12)--L-arabinopyranoside] (9); and the O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl esters of oleanolic acid, echinocystic acid, and hederagenin 3-O-[O--L-rhamnopyranosyl-(12)--D-glucopyranoside]s (8), (10), and (11), respectively. This is the first time that compounds (1), (2), (5), (7), (9), and (10) have been found in this plant.Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 742–746, November–December, 1994. 相似文献
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[reaction: see text] A resin-based chromium catalyst for performing [6pi + 2pi] cycloaddition reactions has been prepared from chloromethylated polystyrene. The catalyst provides cycloadducts in yields comparable to the photochemical and thermal versions of these transformations, and the process is effective with a wide range of 6pi and 2pi reaction partners. 相似文献
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Summary A new glycoside with a rotenoid aglycone — amorphol — has been isolated from the fruit ofAmorpha fruticosa L. It has been established that amorphol is a bioside of amorphigenin and has the structure of the 24-O-[O--L-arabopyranosyl-(16)--D-glucopyranoside] of 22,24-dihydroxy-22,23-dihydrorotenone.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 464–468, July–August, 1974. 相似文献
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Talgat M. Inerbaev Vladimir R. Belosludov Rodion V. Belosludov Marcel Sluiter Yoshiyuki Kawazoe Jun-Ichi Kudoh 《Journal of inclusion phenomena and macrocyclic chemistry》2004,48(1-2):55-60
In this work, the electronic, structural, dynamic andthermodynamic properties of structure II, H and tetragonalAr clathrate hydrates have been calculated and the effectof multiple occupancy on their stability has been examinedusing first-principles and lattice dynamics calculations.The dynamic properties of these clathrates have beeninvestigated depending on the number of guest moleculesin a clathrate cage. It has been found that selectedhydrate structures are dynamically stable. The calculatedcell parameters are in agreement with experimental data.We also report the results of a systematic investigationof cage-like water structures using first-principles calculations. Ithas been observed that Ar clusters can be stabilized indifferent water cages and the stability is strongly dependenton the number of argon atoms inside the cages. 相似文献