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71.
Ohne Zusammenfassung
Ins Deutsche übersetzt von E. Lottermoser (Leipzig). 相似文献
72.
73.
V. M. Dem’yanovich I. N. Shishkina Ya. A. Gritsyuk K. A. Potekhin A. V. Chesnova L. D. Ashkinadze 《Russian Journal of Organic Chemistry》2005,41(4):556-559
The condensation of lithiated (S)-N,N-dimethyl-1-phenylethylamine with o-methoxybenzophenones occurs in a nonstereoselective fashion due to possible coordination of lithium not only at the carbonyl group but also at the oxygen atom of the ortho-methoxy group.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 567–570.Original Russian Text Copyright © 2005 by Dem’yanovich, Shishkina, Gritsyuk, Potekhin, Chesnova, Ashkinadze. 相似文献
74.
We discuss the parametrization of quantum groups in terms of independent operators. We find that this consideration leads to the parametrization ofSU q(2) in terms of aq-oscillator plus a commuting phase. The commuting phase is naturally identified with the subgroupU(1) and the remaining cosetSU q(2)/U(1)=CP q(1) consists of aq-oscillator. For unitary quantum groupsSU q (n), the analogous construction results in the quantum projective spaceSU q(n+1)/U q (n)=CP q (n) being identified with then-dimensionalq-oscillator. This yields a nonlinear action of the quantum groupSU q(n+1) on then-dimensionalq-oscillator. 相似文献
75.
We first investigate the high-temperature behavior of a two-parameter deformed quantum group fermionic gas with GLp,q(2) symmetry, where (p,q)C×C. We then discuss both the structural and thermodynamical differences between GLp,q(2)- and SUr(2)-fermions with r=p/q where (p,q)R×R. 相似文献
76.
The high-temperature bromination of 1a,2,7,7a-tetrahydro-1H-cyclopropa[b]naphthalene and its carboethoxy derivative was studied. Reaction of the title compound with 1 mol of bromine in refluxing carbon tetrachloride resulted in the formation of ring-opening products. In the case of the carboethoxy derivative, bromination took place both regio- and stereospecifically at the benzylic positions, the cyclopropane ring did not undergo bond cleavage. A mechanism for the formation of the products and their dehydrobromination reactions is discussed. 相似文献
77.
Exponential factor optimization in characteristic function method for electrically charged particles
Metin Demiralp 《International journal of quantum chemistry》1983,23(3):779-787
In this work, the simplest basis function on hyperspherical coordinates with an optimization parameter is used to construct the characteristic function for a system of electrically charged particles. The first three coefficients of the serial expansion of the characteristic function in powers of eigenvalue parameter are evaluated in terms of well-known functions. The construction of a Padé table for this expansion with the aid of these coefficients, a theoretical discussion, the optimization of the exponential parameter, evaluation of ground state energies for certain systems, and finally comparison of accuracy increments due to optimization for several systems complete the work. 相似文献
78.
L. N. Dem’yanets V. V. Artemov L. E. Li Yu. M. Mininzon T. G. Uvarova 《Crystallography Reports》2008,53(5):888-893
Zinc oxide low-dimensional hollow structures in the form of hexagonal plates with holes at the center of the {0001} facets are synthesized in the course of the low-temperature interaction of ZnO precursors with aqueous solutions of potassium fluoride under hydrothermal conditions. Crystals have the shape of single-walled or multiwalled “nuts.” The high optical quality of the structures is confirmed by cathodoluminescence data at room temperature. The mechanism of the formation of ZnO “nanonuts” and products of the interaction of the ZnO precursors with KF is proposed. 相似文献
79.
Cycloaddition reactions of the 1.2-benzocycloheptatriene with singlet oxygen and 4-phenyl-1.2.4-triazolin-3.5-dione (PTAD) have been studied. For the first time, addition of the PTAD to a cycloheptatriene derivative has been observed. 相似文献
80.
Bromination of 3-bromo-6,7-benzobicyclo [3.2.1] octa-2,6-diene at ?50°C gave anti-tribromo adduct (5) in essentially quantitative yield. The double dehydrobromination of (5) was achieved using potassium tert.- butoxide to give 2-bromo-benzobarrelene (7). Reaction of (7) with n-BuLi and subsequent quenching with CH3I, CO2, and dimethylformamide afforded the corresponding substituted benzobarrelenes in high yield. 相似文献