Phase diagram of the quasi-binary system $Tb(Fe_{1-x}Mn_x)_2$ synthesized at high pressures
Phase diagram of the quasi-binary system $Tb(Fe_{1-x}Mn_x)_2$ synthesized at high pressures
А.S. Ilyushin, I.А. Nikanorova, А.V. Tsvyashchenko, М.A.А. Gudaev, Shi Lei, and Zhou Guien
Синтезированы при давлениях до 8 ГПа и исследованы методами рентгеновского дифракционного анализа сплавы квазибинарной системы $Tb(Fe_{1-x}Mn_x)_2$. Построена фазовая диаграмма системы в координатах «состав—давление».
Show AbstractChanges in magnetic properties of the amorphouв alloy $Fe_{84}B_{16}$ during crystallizatian
Changes in magnetic properties of the amorphouв alloy $Fe_{84}B_{16}$ during crystallizatian
А.А. Novakova, Т.Yu. Кiaeleva, and I.А. Aleksandrova
Исследованы механизм и кинетика кристаллизации аморфного сплава $Fe_{84}B_{16}$ с помощью дифференциальной - сканирующей калориметрии, термомагнитного анализа, рентгенодифракционного анализа и температурной съемки мёссбауэровских спектров в интервале температур от 25 до 575 °С. Определены температуры кристаллизации, эффективная энергия активации начала кристаллизации, температуры Кюри и температурные зависимости магнитных сверхтонких параметров для аморфной матрицы и выделившихся кристаллических фаз.
Show AbstractThe method of projection operators in the theory of pulsed NMR processes with selective irradiation
The method of projection operators in the theory of pulsed NMR processes with selective irradiation
V.S. Tumanov
The method of projection operators is applied to the theory of pulsed nuclear magnetic resonance processes with selective irradiation. The use of the projection operator method alone and in combination with the known one-transition operator method is considered. In particular, general formulas are derived that describe the evolution of the density operator in the case of arbitrary first-order spectra.
Show AbstractPhase spaces of nonzero curvature and the evolution of physical systems
Phase spaces of nonzero curvature and the evolution of physical systems
A.G. Popov
It is proposed that phase spaces of nonzero cunature (non-Euclidean phase spaces) be used to describe physical phenomena. The singularities of these spaces show good correspondence to the invariant (equilibrium) states of physical systems. Pseudospherical phase spaces are investigated for which the Lobachevski geometry is valid. General principles are stated for the evolution of phenomena described, in particular, by the sin-Gordon, Korteweg-de Vries, Burgers, Liouville, and other equations.
Show AbstractImage information content in the problem of interpretation of tunnel electron microscope measurements
Image information content in the problem of interpretation of tunnel electron microscope measurements
V.P. Manolov, Yu.P. Pyt'ev
The maximum resolving power of a measuring-computer system based on a scanning tunnel microscope (STM) has been investigated in the linear approximation. A sequence of surface classes of increasing dimension is denned. In each of the classes the surface is reconstructed with maximum accuracy from STM measurement data. The dependence of the error in the reconstruction of the surface coordinates on the noise-to-signal ratio is determined. The conditions are found for an optimal discretization of STM measurements that provides maximum accuracy in the reconstruction of measured surface.
Show AbstractMultistage emission of $\gamma$-quanta in reactions of neutron capture by nuclei at medium energies
Multistage emission of $\gamma$-quanta in reactions of neutron capture by nuclei at medium energies
F.A. Zhivopistsev, V.A. Ivanov, Hurelsukh Sar-Odyn
The possibility of describing a nonequilibrium gamma spectrum in the $(n,\gamma)$ reaction at $\varepsilon_n$ = 14.1 MeV using the quantum model of statistical multistage compound processes (SMCP) and statistical multistage direct processes (SMDP). It is shown that a consistent description of experimental data can be obtained for the $(n,\gamma)$ reactions at $\varepsilon_n$ = 14.1 MeV on $^{93}Nb$ and $^{133}Cs$ nuclei if contributions from lSDP, 2SDP, SMCP, and equilibrium gamma emission are taken into account.
Show AbstractA model of self-induced transparency in a medium of nonlinear oscillators
A model of self-induced transparency in a medium of nonlinear oscillators
V.A. Kubarev
The problem of propagation of wave packets in a resonant medium consisting of classical nonlinear oscillators is considered. For the case of transverse propagation in a cold collisionless magnetoactive plasma, solutions of the type of solitary waves are obtained. An analogy with the phenomenon of optical self-induced transparency is noted.
Show AbstractDiffraction of radio waves by a random phase screen with small-scale and large-scale inhomogeneities
Diffraction of radio waves by a random phase screen with small-scale and large-scale inhomogeneities
A.G. Vologdin, V.D. Gusev, L.I. Prikhod'ko
The problem of diffraction of radio waves by a random phase screen with small-scale and large-scale inhomogeneities (LSI) of the ionosphere is considered. The solution of this problem helps analyze the effect of the LSI focusing action on the statistical characteristics of fast fluctuations of the field reflected by the ionosphere. In particular, it is noted that the focusing (defocusing) action of LSI results in a quasi-periodic variation of the shape and the orientation of the characteristic ellipse of the correlation coefficient of the field on the Earth's surface, which is confirmed experimentally.
Show AbstractThe range of applicability of the geometrical optics approach for a refractive medium with random inhomogeneities
The range of applicability of the geometrical optics approach for a refractive medium with random inhomogeneities
V.D. Gusev, S.M. Golynskii, Wu Xiaoping
Based on the criterion of nonintersection of rays, a new condition is found that determines the range of applicability of the geometrical optics approximation for oblique incidence of radiation on a refractive scattering layer. It is shown that the area of validity of the geometrical optics approach substantially depends on the "intensity" of fluctuations of the medium permittivity. The derived condition considerably extends the applicability of the ray interpretation of the wave field in the medium in question compared to the standard determination of the region of geometrical optics.
Show AbstractExcitation and dynamics of strongly nonlinear Trivellpece-Gould modes
Excitation and dynamics of strongly nonlinear Trivellpece-Gould modes
I.M. Aleshin, L.S. Kuz'menkov, 0.0. Trubachev
Conditions are found for the excitation of strongly nonlinear waves in magnetized plasma in a cylindrical waveguide by an ion bunch. It is shown that both periodic and solitary waves can be excited and the form of the waves strongly depends on the plasma temperature.
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