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951.
We present a theoretical analysis of the Doppler-spectrum properties of a microwave radar signal scattered by the sea surface at small incidence angles. The dependences of Doppler-spectrum width and shift on the wind velocity and wave development stage and their azimuthal dependence are analyzed. The case of mixed sea (wind wave plus swell) is also considered. The JONSWAP spectrum model is used to describe sea waves. The study shows that Doppler-spectrum parameters are sensitive to variation of sea-surface state; for example, for the case of developed sea waves, an increase in wind velocity by 1 m/sec leads to increases in the Doppler-spectrum width and shift by 15 Hz and 3 Hz, respectively. It is shown that for the case of a moving radar the Doppler spectrum remains sensitive to variation of sea- surface state with a sufficiently narrow radar directivity pattern. Estimates show that in the case of a single sea- wave system on the surface, using Doppler-spectrum parameters we can, in principle, determine wave type (developing wind wave, developed wind wave, or swell), dominant wavelength, wave propagation direction, and wave height; wind velocity, direction, and acceleration distance can be determined for wind waves.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 39, No. 5, pp. 517–526, May, 1996.This paper was supported by the Russian Foundation for Fundamental Research (project 93-02-15892). 相似文献
952.
M. I. Kudryavtsev V. M. Pankov A. V. Bogomolov Yu. I. Denisov G. Ya. Kolesov Yu. I. Logachev S. I. Svertilov 《Radiophysics and Quantum Electronics》1996,39(11-12):1027-1030
The SPEKTR module of the MIR orbital station was launched in May 1995. The multipurpose experiment was based on the GRIF-1 research complex consisting of an oriented X-ray spectrometer, a spectrometer of gamma-quanta and neutrons, a spectrometer of electrons and protons with a large geometrical factor, and a spectrometer of electrons, protons, and nuclei with a small geometrical factor. The solar geophysical aspects of the experiment included the measurements of spectral and temporal parameters of solar hard electromagnetic (0.01–50 MeV) and neutron (>20 MзB) radiation, the study of spectral, temporal, and spatial characteristics of energetic electrons (0.04–1.5 MeV), protons, and nuclei (1–200 MeV/nucleon) in the circumterrestrial space, as well as the correlations of these parameters with solar activity phenomena. 相似文献
953.
954.
本文将t(t是大于2的整数)元整系数多项式看成为系数为t-2元整系数多项式的二元多项式,建立了多元整系数多项式因式分解的一种新理论,进而得到了分解多元整系数多项式的一个有力的算法。 相似文献
955.
Surface-wave gas discharges sustained under the conditions of a diffusion controlled regime are studied on the basis of the fluid plasma model. The self-consistent behaviour of the plasma density and of the field intensity along the discharge length is obtained. It is shown that the nonlinearity in the particle balance equation due to stepwise ionisation determines the plasma density in terms of the field intensity and ensures self-consistent behaviour of the wave ? discharge characteristics in a diffusion controlled regime. 相似文献
956.
Yu. B. Sedov 《Fluid Dynamics》1993,28(3):425-426
Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 3, pp. 167–168, May–June, 1993. 相似文献
957.
THE SCHWARZIAN DERIVATIVE IN SEVERAL COMPLEX VARIABLES(II) 总被引:1,自引:0,他引:1
THESCHWARZIANDERIVATIVEINSEVERALCOMPLEXVARIABLES(II)GONGSHENGYUQIHUANGZHENGXUEANManuscriptreceivedAugust30,1996.De... 相似文献
958.
We estimate the concentration functions of n-fold convolutions of one-dimensional probability measures. The Kolmogorov–Rogozin inequality implies that for nondegenerate distributions these functions decrease at least as O(n
–1/2). On the other hand, Esseen(3) has shown that this rate is o(n
–1/2) iff the distribution has an infinite second moment. This statement was sharpened by Morozova.(9) Theorem 1 of this paper provides an improvement of Morozova's result. Moreover, we present more general estimates which imply the rates o(n
–1/2). 相似文献
959.
A. A. Mukhin V. Yu. Ivanov V. D. Travkin S. P. Lebedev A. Pimenov A. Loidl A. M. Balbashov 《JETP Letters》1998,68(4):356-362
The electrical conductivity, magnetic susceptibility, magnetization, and submillimeter (v=5∓20 cm−1) permittivity and dynamic conductivity of La1−x
Sr
x
MnO3 (0≤x≤ 0.45) single crystals are investigated. The anomalies in the temperature dependences of these quantities are identified
with diverse magnetic and structural phase transformations, including antiferromagnetic and ferromagnetic ordering, structural
transitions between strongly distorted (Jahn-Teller) and weakly distorted (pseudocubic) orthorhombic phases, structural transitions
to a rhombohedral phase and unusual transitions to a polaron-ordering state. As a result, the complete T-x phase diagram of the system La1−2x
Sr
x
MnO3 is constructed in a wide interval of temperatures T=4.2∓1050 K and concentrations x=0−0.45.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 4, 331–336 (25 August 1998) 相似文献
960.
A. Yu Yeremin N. L. Zamarashkin S. A. Kharchenko 《Journal of Mathematical Sciences》1998,89(6):1591-1606
An algorithm for translating unstable eigenvalues of single-input partial pole assignment problems based on rank-one transformations
is suggested. Special attention is paid to the practical case where translations are constructed using inexact spectral information
provided by the Arnoldi procedure. Estimates of the resulting perturbations of stable and translated poles are derived. These
estimates depend on the accuracy of spectral information about the unstable poles. The algorithm proposed is illustrated with
numerical examples. Bibliography: 11 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 229, 1995, pp. 5–28.
Translated by A. Yu. Yeremin. 相似文献