Production of high-amplitude waves by a relativistic beam in a slow-wave system
Production of high-amplitude waves by a relativistic beam in a slow-wave system
V.K. Grishin
An exact solution to the nonlinear kinetic equation is used to examine the limiting states arising in a slow-wave system with beam generation of harmonic waves. The limiting current for single-mode generation is estimated. Efficient energy transfer from the beam to the wave is possible only for a relativistic beam in a slow-wave system. The choice of optimal parameters is discussed for generating waves in a specified wavelength range.
Show AbstractPassage of a shock wave through a region with temperature or concentration inhomogeneities
Passage of a shock wave through a region with temperature or concentration inhomogeneities
M.V. Piskareva and F.V. Shugaev
Measurements have been made on the motion of a shock wave in a hot gas at constant pressure; differential relationships have been derived for the one-dimensional motion in a perfect gas in which the temperature and velocity are dependent on a coordinate; other results have been obtained for a gas mixture having a distribution of the component concentrations at constant pressure and temperature. Formulas are given for the time derivative of the Mach number of the wave and the derivative of the density with respect to the coordinate in the gas behind the wave for the instant when the wave encounters the boundary of the nonuniformity. Results are given from numerical calculations on the passage of a shock wave through a gas with a negative density gradient at constant pressure. The theoretical values for the change in shock-wave speed are compared with the measured ones.
Show AbstractCharacteristics of a turbulent density-dependent bottom current under natural conditions
Characteristics of a turbulent density-dependent bottom current under natural conditions
A.A. Kuznetsov, Yu.G. Pyrkin, and L.V. Sokolov
Results are presented on bottom density flows under natural conditions; vertical distributions have been derived for the density, turbidity, mean velocity, scale of the fluctuations in the two flow-speed components, and the turbulent frictional stress. It is concluded that the mechanism of the flow near the bottom is similar to the mechanism for the liquid boundary of the bottom density flow. Although the results are in qualitative agreement with published data, there are substantial quantitative discrepancies over the major turbulent characteristics.
Show AbstractMeasurements on the passage of a vortex ring through a shock wave
Measurements on the passage of a vortex ring through a shock wave
Ibrahim Maher Aziz (Egypt), A.I. Klimov, and F.V. Shugaev
Measurements have been made on the interaction of a shock wave with a vortex ring at M of 1.1-3; the velocity of the ring with respect to the gas is reduced after passage through the shock wave. Also, the vortex ring is disrupted at speeds in excess of 160 m/sec.
Show AbstractEffects of compound states on the structures of the giant dipole resonances in 60^Ni,90^Zr,208^Pb
Effects of compound states on the structures of the giant dipole resonances in 60^Ni,90^Zr,208^Pb
Ф.А. Живописцев, К.В. Шитикова
The effects of compound states of 2p2h type have been examined for giant dipole resonances having T< and T> in and 60^Ni, 90^Zr,208^Pb; calculations have been performed on the structure of the giant resonances (T< and T>) and on the energy spectra of the photonucleons.
Show AbstractShock-wave production in a transmission line including mis varicaps
Shock-wave production in a transmission line including mis varicaps
A.M. Strel'tsov
Shock-wave shapes are considered for a medium without dispersion whose nonlinearity can be approximated by a piecewise-linear function; recordings have been made of the distortion of a sine wave in a line of low-pass filter type containing MIS varicaps operating at various bias levels.
Show AbstractAn exact calculation on the nuclear-volume effect in atomic spectra
An exact calculation on the nuclear-volume effect in atomic spectra
N.N. Kolesnikov and A.B. Skvortsov
Analytical and numerical solutions are given for the effects of nuclear volume on the positions of the electronic levels.
Show AbstractA finite-element analysis of the vibrations of a cylindrical shell in a liquid
A finite-element analysis of the vibrations of a cylindrical shell in a liquid
V.P. Kandidov and S.A. Khristochevskii
The finite-element method is applied to the free and forced oscillations of a shell in a liquid; the matrix equation is derived for the pressure of the liquid on the shell, in which a polynomial of first degree is used to approximate the density of the simple sources at the surface of the shell. A numerical calculation is presented for a particular shell, and the resonant frequencies of the shell in a liquid are determined.
Show AbstractEmission from a uniformly moving charge in a medium with two discontinuities in the dielectric constant
Emission from a uniformly moving charge in a medium with two discontinuities in the dielectric constant
V.A. Davydov
An expression is derived for the intensity of the emission from a uniformly moving charge when there is a double discontinuity in the dielectric constant of the medium; limiting cases are examined.
Show AbstractSolution of an equation chain for correlation functions
Solution of an equation chain for correlation functions
I.P. Bazarov and P.N. Nikolaev
An equation chain has been solved for correlation functions on the basis that the correlation integrals are small; the first approximation is obtained for a homogeneous system. The result is the same as the expression derived by Bogolyubov by expanding the distributions as series in terms of a small parameter, while for a crystal it is the same as the analogous expression for the binary distribution.
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