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排序方式: 共有379条查询结果,搜索用时 765 毫秒
51.
52.
Anton A. Kohutych Ruslan M. Yevych Sergij I. Perechinskii Yulian M. Vysochanskii 《Central European Journal of Physics》2010,8(6):905-914
The temperature and frequency dependencies of sound attenuation for the proper uniaxial ferroelectric Sn2P2S6, which has a strong nonlinear interaction of the polar soft optic and fully symmetrical optic modes that is related to the
triple well potential, were studied by Brillouin spectroscopy. It was found that the sound velocity anomaly is described in
the Landau-Khalatnikov approximation with one relaxation time. For explanation of the observed temperature and frequency dependencies
of the sound attenuation in the ferroelectrric phase, the accounting of several relaxation times is needed and, for quantitative
calculations, the mode Gruneisen coefficients are more appropriate as interacting parameters than are the electrostrictive
coefficients. Relaxational sound attenuation by domain walls also appears in the ferroelectric phase of Sn2P2S6 crystals. 相似文献
53.
A.?V.?Zaitsev G.?A.?Ovsyannikov K.?Y.?Constantinian Yu.?V.?Kislinski? A.?V.?Shadrin I.?V.?Borisenko P.?V.?Komissinskiy 《Journal of Experimental and Theoretical Physics》2010,110(2):336-344
It is shown experimentally that the superconducting current density in Nb/Au/Ca1 − x
Sr
x
CuO2/YBa2Cu3O7 − δ hybrid superconducting heterostructures with a Ca1 − x
Sr
x
CuO2 anti-ferromagnetic (AF) cuprate interlayer is anomalously high for interlayer thicknesses d
M
= 10–50 nm and the characteristic damping length for superconducting correlations is on the order of 10 nm. The experimental
results are explained on the basis of theoretical analysis of a junction of two superconductors (S′ and S) connected by a
magnetic multilayer with the AF ordering of magnetization in the layers. It is shown that with such a magnetization ordering,
anomalous proximity effect determined by the singlet component of the condensate wavefunction may take place. As a result,
the critical currents in S′/I/AF/S and S′/I/N/S structures (I denotes an insulator, and N, the normal metal) may coincide
in order of magnitude even when the thickness of the AF interlayer considerably exceeds the decay length of the condensate
wavefunction in ferromagnetic layers. 相似文献
54.
Airborne radars are widely used to perform a large variety of tasks in an aircraft (searching, tracking, identifying targets, etc.) Such tasks play a crucial role for the aircraft and they are repeated in a “more or less” cyclic fashion. This defines a scheduling problem that impacts a lot on the quality of the radar output and on the overall safety of the aircraft. 相似文献
55.
Ivanna Yu. Danyliuk Ruslan I. Vas’kevich Alla I. Vas'kevich Eduard B. Rusanov Mykhailo V. Vovk 《Phosphorus, sulfur, and silicon and the related elements》2019,194(1-2):156-162
Heterocyclization of N-(pyrazol-3-yl)styrylacetamides with arenesulfenyl chlorides yields the corresponding tetrahydrofuran-2-iminium perchlorates isolable after chromatography as trans-5-aryl-4-(arylthio)tetrahydrofuran-2-ones and 5-aryl-4-(arylthio)-1-(pyrazol-3-yl)pyrrolidin-2-ones, with the latter predominating. N-(Pyrazol-4-yl)styrylacetamides react under analogous conditions to give 5-aryl-4-(arylthio)-1-(pyrazol-4-yl)pyrrolidin-2-ones, 4-aryl-3-(arylthio)-4-chloro-N-(1-methylpyrazol-4-yl)butanamides, and tetrahydrofuran-2-iminium perchlorates which, when chromatographed, produce 5-aryl-4-(arylthio)dihydrofuran-2(3H)-ones and 4-aryl-3-(arylthio)-4-methoxy-N-(1-methyl-1H-pyrazol-4-yl)butanamides. 相似文献
56.
57.
Ruslan V. Vovk Georgij Ya. Khadzhai Oleksandr V. Dobrovolskiy 《Applied Physics A: Materials Science & Processing》2014,114(3):997-1002
A single-sized dielectric cylinder-based metamaterial is fabricated from TiO2 nanoparticles, using a bottom-up approach. The sub-elements constituting the metalayer are embedded in a nonmagnetic transparent host matrix in the microwave regime and arranged in a square lattice. We demonstrate numerically and experimentally a broadband magnetic activity. The key feature to achieve this performance remains in the high aspect ratio of the metamaterial building blocks. This is a very promising step towards complex electromagnetic functions, involving low-cost metamaterials with simple fabrication. 相似文献
58.
A combined approach (endohedral doping and exohedral environment) to stabilization of boron clusters with classical fullerene structures has been studied. The boron clusters with classical fullerene structures are stable when heteroatomic part of the complex (endohedral atom and exohedral environment) donates in total 18 electrons to the composite system, stability of which depends on the coordination capabilities and donor ability of the endohedral and surrounding atoms. The most effective stabilization is achieved in the case of the endohedral transition metals atoms, whereas the most effective environment is given by the lithium surrounding.
相似文献59.
I. K. Bdikin A. D. Mashtakov P. B. Mozhaev G. A. Ovsyannikov 《Physics of the Solid State》1998,40(4):558-560
X-ray diffraction is used to investigate YBa2Cu3O7?x (YBCO) films on NdGaO3(110) and a ${{(100)CeO_2 } \mathord{\left/ {\vphantom {{(100)CeO_2 } {(1\bar 102)}}} \right. \kern-0em} {(1\bar 102)}}Al_2 O_3 $ heterostructure. Symmetric, asymmetric, and axial geometries for θ and θ/2θ scans are used to obtain diffraction spectra from different crystallographic planes. The orientational and quantitative twinning characteristics of the films are determined. While the crystallographic parameters of these two types of film (the films are c-axis oriented with c=11.67 Å) are similar, there are differences in the twin structure. In particular, the features of the NdGaO3 structure lead to the appearance of an angle differing from 90° (90.20°) between the possible (110) and θ/2θ twin planes in a YBCO film and a different number of twin components in each system of twins. It is concluded from an analysis of the broadening of reflections, which are sensitive to twinning, that there is not twinning in a 60% film of YBCO on Al2O3 with a CeO2 buffer layer. 相似文献
60.
Ruslan?K.?MuharlyamovEmail author Tatiana?N.?Pankratyeva 《International Journal of Theoretical Physics》2016,55(2):1093-1104
We investigate the Bianchi type-I cosmological model with the scalar and electromagnetic fields possessing non-minimal couplings. They contain the Mie invariant that leads to the flat Friedman’s cosmological model. We found the lagrangian for interaction, which the isotropization process of the expansion takes place. Two cases are considered, when the Mie invariant is constat or time-dependent. We study the canonical scalar field and the phantom one. 相似文献