Estimating the components of the water-air heat flux in laboratory investigations
Estimating the components of the water-air heat flux in laboratory investigations
V.N. Aksenov, E.G. Andreev, I.D. Bakanov
Results are given of laboratory investigations of the heat-flux components close to the water-air interface with various values of the temperature difference between the media. The estimates presented are useful for more correct modeling of the full-scale conditions of heat transfer in laboratory experiments.
Show AbstractStructure of strong shock waves in argon
Structure of strong shock waves in argon
Sufian Aslam, A.P. Ryazin
The change in structure of a shock wave (SW) in argon with increase in its intensity is investigated experimentally for initial pressures of 3 and 25 torr and velocities in the ranges 6-8.5 and 3.5-6.2 km/sec. It is established that two different SW structures exist, as well as a transitional region in which the SW structure is unstable.
Show AbstractKinetics of the dissociation of diatomic molecules with laser excitation of low vibrational levels and effective heat extraction
Kinetics of the dissociation of diatomic molecules with laser excitation of low vibrational levels and effective heat extraction
S.G. Grebenyuk, A.I. Osipov
The influence of the initial conditions and form of the exciting pulse on the kinetics of dissociation is analyzed over the whole time interval from the initial stages to the establishment of steady conditions. It is shown that the initiation of dissociation by external radiation is more favorable at low translational temperatures than at high temperatures, and an exponential form of the pumping pulse is most effective here.
Show AbstractQuantum chromodynamics and the quasi-classical approximation
Quantum chromodynamics and the quasi-classical approximation
M.K. Ermolaev, N.F. Nelipa
An expression is obtained for the amplitude of quantum chromodynamics in the quasi-classical approximation.
Show AbstractStatistical characteristics of random signals in a nonlinear medium
Statistical characteristics of random signals in a nonlinear medium
A.S. Gorshkov, L.G. Lyashed'ko, I.T. Trofimenko
Theoretical and experimental results for the variation in distribution function of a narrow-band noise signal propagating in a nonlinear weakly dispersive medium are compared. Dissipation smooths the nonlinear distortions of the distribution function, and cubic nonlinearity leads to asymmetry.
Show AbstractWavefront control of optical radiation propagating in a medium that moves at variable velocity
Wavefront control of optical radiation propagating in a medium that moves at variable velocity
V.A. Trofimov
Compensation of the distortions of optical radiation passing through a nonlinear layer of a medium which is moving at variable velocity is considered. The stability conditions and modes of development of the initial slope of the beam wavefront are determined.
Show AbstractLimiting efficiency of plasma amplifier
Limiting efficiency of plasma amplifier
V.K. Grishin, M.F. Kanevskii
The efficiency of the interaction of a charged beam with an excited electromagnetic wave is investigated. It is shown that the limiting efficiency of a plasma amplifier is 0.5. The method proposed may be used for estimates in various electrodynamic structures.
Show AbstractSpecial Legendre transformation of generating functionals in the case of SU(2) symmetry
Special Legendre transformation of generating functionals in the case of SU(2) symmetry
A.P. Demichev
The second Legendre transformation of the generating functional is considered for Green's function with respect to some of the bilocal currents realizing an irreducible representation of symmetry groups of the Lagrangian. It is shown that diagrammatic expansion of the functional obtained is of two-particle-reducible type.
Show AbstractDisplacement of terbium atoms in the crystal lattice of the magnetically ordered intermetallide TbFe_2$
Displacement of terbium atoms in the crystal lattice of the magnetically ordered intermetallide TbFe_2$
A.S. Ilyushin, L.A. Kirilicheva, A.P. Perov, Yu.V. Teben'kov
The method of low-temperature X-ray diffractometry is used to study the crystalline structure of the intermetallide TbFe$_2$ in the magnetically ordered state. It is established that the intermetallide TbFe$_2$ has a rhombohedral structure in the temperature range 5-295 K (spatial group $D_{3d}^{5}$). In the elementary cell of the intermetallide TbFe$_2$ , the terbium atoms occupy the positions 2(c) with coordinates 3/8 + x, 3/8 + x, 3/8 + x and 5/8 - x, 5/8 - x, 5/8 - x. The values of the parameter x are determined, and its dependence on the temperature in the range 5-295 K is studied. Displacement of terbium atoms toward each other along the direction <111> is observed experimentally on cooling from 295 to 5 K.
Show AbstractWave and oscillational processes in an active resonant transmission line
Wave and oscillational processes in an active resonant transmission line
E.V. Galuzo, V.I. Kanavets
Processes in an active layer distinguished by an intimate relation between wave and vibrational phenomena, a field structure that is not fixed, and a variable spectrum are investigated experimentally using an active resonant radio frequency transmission line. Conditions of active-layer emission, mutual and induced synchronization of the autogenerators, and the amplification of the external signal are considered. The experimental data are in agreement with the results of numerical modeling of the processes.
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