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Kochkarov A. A. Razinkov S. N. Timoshenko A. V. Shevtsov V. A. 《Journal of Computer and Systems Sciences International》2021,60(5):695-700
Journal of Computer and Systems Sciences International - Using the criterion of the minimum average risk, the statistically optimal algorithm for identifying objects by the same type of parameters... 相似文献
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Valeri Shevtsov Alexander Frolov Igor Lukashevich Eero Ylinen Pekka Malmi Matti Punkkinen 《Journal of Low Temperature Physics》1994,95(5-6):815-833
The combined techniques of ESR and NMR were used to investigate the process of ortho-para conversion in solid molecular hydrogen, containing small amounts ( 500 ppm) of hydrogen atoms as impurity. Although the impurity atoms catalyze the effective conversion of the neighboring ortho-H2, the total catalyzed conversion rate at temperatures from 2.2 K to 4.4 K is much less than expected from the rate of the H atoms recombination. A possible explanation is given in terms of the diffusion of H atoms, which is confined to some defects in the crystal. 相似文献
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Estelle Renard Karine Boutault Valerié Langlois Philippe Guerin 《Polymer Bulletin》1996,36(5):585-592
Summary The configurational analysis of racemic and optically active stereoisomers of 4-[(1-methylpropyl)oxycarbonyl]-2-oxetanone has been carried out by using chiral gas chromatography. This technique has been successful in the stereoisomers composition determination of these -substituted -lactones prepared by two different routes and used as monomers in the preparation of malic acid stereocopolymers. Result are in good agreement with those obtained from high resolution 1H NMR, in the presence of an Europium salt, as chiral shift reagent. This method has been extended to 3-methyl-4-[(1,2,2-trimethyl propyl)oxycarbonyl]-2-oxetanone. The exact knowledge of precursors configurational structure is very important in regard to the obtention of the corresponding polystereoisomers with a strictly controlled enantiomeric or diastereoisomeric composition and consequently with predictable properties. 相似文献
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L. A. Reznichenko L. A. Shilkina S. V. Titov O. N. Razumovskaya V. V. Titov S. I. Shevtsov 《Inorganic Materials》2005,41(5):492-502
X-ray powder diffraction, scanning electron microscopy, and x-ray microanalysis data indicate that Ba, Ca, Sr, Cd, and Pb titanates contain defect structures associated with crystallographic shear. Spatially periodic shear gives rise to modulated displacements of the Ti and O atoms across the shear plane, resulting in long-period structures. The parameters of such structures depend on the nature of the sample (single crystal, ceramic, or powder), its microstructure, and the crystal chemistry of the titanate.__________Translated from Neorganicheskie Materialy, Vol. 41, No. 5, 2005, pp. 573–584.Original Russian Text Copyright © 2005 by Reznichenko, Shilkina, S. Titov, Razumovskaya, V. Titov, Shevtsov. 相似文献
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K. B. Kuznetsov I. A. Kovalev A. N. Nechaev A. I. Ogarkov S. V. Shevtsov A. S. Chernyavskii K. A. Solntsev 《Inorganic Materials》2016,52(12):1235-1239
X-ray diffraction and transmission electron microscopy (TEM) data demonstrate that irradiation with high-energy +24Xe136 ions causes no changes in the grain microstructure of compact zirconium nitride ceramics. According to Raman spectroscopy and high-resolution TEM data, the irradiated ceramics may have local distortions of the zirconium nitride lattice within regions on the order of the lattice parameter in size. 相似文献
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Pierre Carmier Oleksii Shevtsov Christoph Groth Xavier Waintal 《Journal of Computational Electronics》2013,12(2):175-187
We investigate the effect of spin-orbit coupling on the band structure of graphene-based two-dimensional Dirac fermion gases in the quantum Hall regime. Taking monolayer graphene as our first candidate, we show that a quantum phase transition between two distinct topological states—the quantum Hall and the quantum spin Hall phases—can be driven by simply tuning the Fermi level with a gate voltage. This transition is characterized by the existence of a chiral spin-polarized edge state propagating along the interface separating the two topological phases. We then apply our analysis to the more difficult case of bilayer graphene. Unlike in monolayer graphene, spin-orbit coupling by itself has indeed been predicted to be unsuccessful in driving bilayer graphene into a topological phase, due to the existence of an even number of pairs of spin-polarized edge states. While we show that this remains the case in the quantum Hall regime, we point out that by additionally breaking the layer inversion symmetry, a non-trivial quantum spin Hall phase can re-emerge in bilayer graphene at low energy. We consider two different symmetry-breaking mechanisms: inducing spin-orbit coupling only in the upper layer, and applying a perpendicular electric field. In both cases, the presence at low energy of an odd number of pairs of edge states can be driven by an exchange field. The related situation in trilayer graphene is also discussed. 相似文献