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1.
The electronic spectrum of an icosahedral quasicrystal with a central-atom decoration of the Amman-Mackay network is investigated
in the tight-binding approximation. The quasicrystal is described as a structural limit of the optimal cubic approximants
with increasing period. The electronic spectra for the first four optimal cubic approximants do not contain the hierarchical
gap structure which is typical for the Cantor set of the spectrum of a one-dimensional quasicrystal. At the same time, as
the order of the approximant increases, the spectrum becomes singular throughout the entire energy scale.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 8, 557–562 (25 April 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
2.
We study the possibility of defining the (braided) comultiplication for the GL
q
(N)-covariant differential complexes on some quantum spaces. We discover suchdifferential bialgebras (and Hopf algebras) on the bosonic and fermionic quantum hyperplanes (with additive coproduct) and on the braided matrix algebra BM
q
(N) with both multiplicative and additive coproducts. The latter case is related (forN = 2) to theq-Minkowski space andq-Poincaré algebra. 相似文献
3.
A specific quantum Lax operator, forming a quantum U
q
(sl
n) chain, is suggested. The intertwining R
L
L relation is proved. The invariant local 2+1-dimensional reformulation of the auxiliary linear problem for the L-operator is discussed. 相似文献
4.
This paper significantly extends and generalizes the paragrassmann calculus of our previous paper [1]. Here we discuss explicit general constructions for paragrassmann calculus with one and many variables. For one variable, nondegenerate differentiation algebras are identified and shown to be equivalent to the algebra of (p+1)×(p+1) complex matrices. If (p+1) is a prime integer, the algebra is nondegenerate and so unique. We then give a general construction of many-variable diffeentiation algebras. Some particular examples are related to multi-parametric quantum deformations of the harmonic oscillators.Dedication This paper is in memory of Mikhail Constantinovich Polivanov. One of the authors (A.T.F.) had a privilege to be a friend of him for many and many years. He was not only a distinguished scientist but a true Russian intellectual having deep roots in Russian culture. It is a deep sorrow that we can no more have a talk with him on science, poetry, religion ...Laboratory of Theoretical Physics, JINR, Dubna. SU-101 000 Moscow, Russia. Published in Teoreticheskaya i Matematicheskaya Fizika, Vol. 94, No. 2, pp. 213–231, February, 1993. 相似文献
5.
6.
7.
V. A. Postnikov Ts. V. Kakuliya L. M. Khananashvili Yu. V. Isaev Yu. N. Novikov M. E. Vol'pin 《Russian Chemical Bulletin》1979,28(3):626-627
Conclusions The stirred reaction of graphite with molten lithium gave compounds of composition C6Li, C12Li, and C18Li, for which the identity periods and thicknesses of the filled layers were determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 671–672, March, 1979. 相似文献
8.
Another two methylsteroids of the cycloartane series have been isolated from the epigeal part ofAstragalus alopecurus. The structures of the compounds isolated, cycloalpigenin and cycloalpioside, have been established as (20R,24R)-16,24:20, 24-diepoxycycloartane-3,7,25-triol and (20R,24R)-16, 24:20,24-diepoxycycloartane-3,7, 25-triol 3-O--D-xylopyranoside, respectively, on the basis of chemical transformations and spectral characteristics. The structure of cycloalpigenin has been confirmed by chemical correlation with that of cycloalpigenin D.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 700–708, September–October, 1995. Original article submitted February 1, 1995. 相似文献
9.
The new triterpenoid cycloartane cycloorbigenin C, the structure of which is 23ξ,24ξ-cycloartan-3β,6α,16β,23,24,25-hexaol, was obtained from the aerial part of Astragalus orbiculatus Ledeb. (Leguminosae). The structure of cycloorbigenin C was proved using chemical transformations, IR spectroscopy, electron-impact mass spectrometry, and PMR and 13C NMR spectra interpreted using J-modulation and the 2D NMR spectroscopies: 1H-1H COSY, TOCSY, ROESY, HSQC, and HMBC. 相似文献
10.