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991.
A plasma opening switch fed by a helical magnetic explosion generator is developed. A plasma sheath with an axial length of ≈4 cm and an electron density of ~1017 cm?3 is produced in the electrode gap of the switch by six coaxial gaseous-plasma injectors. A series of explosion experiments shows that the system developed allows one to study the switch at currents of about 2 MA.  相似文献   
992.
Pacific Oceanographic Institute, Far-East Branch of the Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 3, pp. 325–327, March, 1991.  相似文献   
993.
Pacific Ocean Oceanographic Institute, Far East Division of the Academy of Sciences of the USSR. Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 1, pp. 89–90, January, 1991.  相似文献   
994.
This paper presents a theoretical study of second-harmonic generation (SHG) by a focused pump beam in the interior of an isotropic medium, experimentally observed earlier. It shows that the spatial dispersion of the quadratic optical response of the substance can be responsible for this nonlinear process even when a macroscopic inversion center is present in the medium. It is established that this effect, which is impossible in the plane-wave approximation, also does not occur when a Gaussian pump beam with uniform distribution of the polarization state of the wave field over the cross section is used, but that the presence in the pump beam of higher transverse modes with polarization different from the fundamental mode can cause an SHG signal to appear. The conditions for a wave to appear at the doubled frequency are found, analytical dependences for its electric field and total power on the propagation coordinate, the degree of focusing, and the other parameters of the problem are obtained, and the requirements on the optimum experimental geometry are formulated. The dependence of the signal-beam power on the wavevector detuning is studied, and it is shown that interference effects can cause the wave at the second harmonic to disappear when a normal dispersion law is obeyed in the region between the fundamental and doubled frequencies. Zh. éksp. Teor. Fiz. 113, 1261–1276 (April 1998)  相似文献   
995.
996.
997.
We propose a two-parameter bifurcation analysis of the dynamics of a system of two identical asymmetrically coupled Brusselators. The stability boundaries of the inhomogeneous steady states and periodic attractors are calculated as the functions of the constraint force and one of the free parameters. The coexistence of different attractors giving rise to multirhythmicity of the dynamics is studied as well as the bifurcation transitions between them. It is shown that the relaxation ability of an oscillator plays an important role in the simplification of the phase diagram, since it removes the overlapping of the existence region for different solutions. We assume that the results primarily characterize the properties of the diffusion coupling and, therefore, they can be applied in the study of other oscillator systems.P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 5, pp. 373–401, May, 1995.  相似文献   
998.
The turbulent flow and coupled heat transfer in the cavity between the rotor and stator is numerically simulated. Reynolds-averaged Navier-Stokes equations closed with equations of the k-ɛ turbulence model are used to calculate the viscous compressible gas flow characteristics and heat transfer; the unsteady heat conduction equation is used to calculate the temperature field in the metal. The influence of the mass flow rate of the coolant on the flow structure and efficiency of cooling of the rotor and stator walls is studied. The calculated results are compared with experimental data.  相似文献   
999.
The influence of the basic factors of cryogenic forcing on formation of the middle zone on the sonic boom and aerodynamic characteristics of the flying vehicle is studied by experimental and numerical methods. Experimental data obtained with alcohol or liquid nitrogen as an injected liquid are used for comparisons; as a result, the total effect of temperature and coolant evaporation can be determined. The influence of temperature is studied by means of numerical simulations of the cryogenic action of distributed injection of air. A comparison of numerical and experimental data reveals the effect of the coolant evaporation process on perturbed flow formation. It is demonstrated that evaporation of the coolant outgoing onto the vehicle surface should be intensified to increase the efficiency of cryogenic forcing (to decrease the coolant flow rate).  相似文献   
1000.
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