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1.
The inflationary unvierse model predicts the density parameter 0 to be 1.0 with the cosmological constant 0 usually taken to be zero, whereas observational estimates give 00.2 and 010-57 cm–2. It was found, however, that the observed variation of angular diameter with redshift for extragalactic radio sources could be interpreted in terms of a low density universe with linear size evolution of the sources for either an inflationary model with 0 or an open model with =0.  相似文献   

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(, 1969). ( ), ( ), , , . , (=), , , .. , . , , - ( ), ( ). , .
This paper is a continuation and a generalization of one published earlier (Duboshin, 1969): it discusses the problem whether there exist the Lagrangian and the Eulerian solutions of the generalized three-body (material points) problem. Every point in this generalized problem acts on another, one with a force (attractive or repulsive) directed along the straight line passing through these points, and in an arbitrary manner depending on time, mutual distance and its derivatives, the first and the second. Here, generally speaking, the third axiom of dynamics (law of action and reaction) is not presupposed as fulfilled, that is, it is supposed that every two material points interact in a different way.This most general assumption being made, we establish the conditions which must dictate the laws of the interactions, so that the three points can always remain at the apexes of the equilateral triangle (Langrangian solution), or remain always on a straight line (Eulerian solution).The author believes that such general treatment of the three-body problem can be useful for theoretical studies in celestial mechanics and also for practical applications in the study of isolated stellar systems.
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, , . . ( I), ( II). I , () . -, . , , (R/R i)2/3, R/R i- . ( II) . , . , , , . , . , , . , , - , , . , , , , . , . . . 1969 .  相似文献   

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An approximate analytical expression for wave normal angle g0, at which whistler-mode group velocity is directed along magnetic field line in a hot anisotropic plasma, is derived. This expression is simple enough for practical applications in the magnetospheric conditions and is compatible with the results of numerical analysis for wave frequencies below but not close to the half of electron gyrofrequency.  相似文献   

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N. Seehafer 《Solar physics》1978,58(2):215-223
At first it is shown that a magnetic field being force-free, i.e. satisfying × B = B, with = constant ( 0) in the whole exterior of the Sun cannot have a finite energy content and cannot be determined uniquely from only one magnetic field component given at the photosphere. Then the boundary value problem for a semi-infinite column of arbitrary cross section is solved by a Green's function method.  相似文献   

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The paper suggests an explanation of the deviations from the power law which are observed in frequency spectra of discrete radio sources at decametric wavelengths. It has been shown that a possible mechanism of the deviations is a combined effect of the stimulated and spontaneous scattering of relativistic electrons in the turbulent plasma of a source, as well as ionization energy losses thereof. The distribution function of the relativistic electrons, empirically established in an earlier paper (Braudeet al., 1971) has been derived from the kinetic equation. For a number of discrete sources the turbulence energy density and the plasma concentration are deduced with the aid of experimental data on low-frequency radio spectra.
. , , . , (Braude et al, 1971), . .
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For a special choice of parameters the plane problem of the motion of a passively gravitating material point in the gravitation field ofn fixed centres is reduced to quadratures.
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, . , , . , , -, This article investigates the dynamics of a system for damping the nutating motion of a spin-stabilized satellite. The equations of motion of the satellite-damper system are derived omitting consideration of the influence of external torques. The conditions of stability of the stationary spinning are obtained and the optimal parameters of the satellite and the damper ensuring a maximal rate of damping of the nutation motion are determined.  相似文献   

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The solutions of the Einstein and Einstein-Maxwell equations for magnetofluid with cosmological constant are obtained for plane-symmetric space-time. We recover the results of Hojman and Santamarina in a special case when the magnetic field is made to vanish. It has also been shown that under a suitable transformation the cases =0 and 0 are mathematically equivalent.  相似文献   

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