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1.
The exact solution of the problem of ion transport current in an electrolyte in the presence of a conjugate flow of solvent
is obtained in the framework of the one-dimensional Gurevich-Kharkats diffusion-migration model; the conditions for the existence
of the solution are analyzed. 相似文献
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Phase synchronization in a system of three virtual-cathode microwave oscillators (vircators) simulated by coupled van der Pol oscillators is studied. The phasing dynamics of the vircators is visualized with the phase portraits of the system in the triangular coordinates. Different phasing conditions are found. 相似文献
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We consider a terahertz laser based on optically pumped graphene layer and bilayer as the active media and suggested waveguide
structure. Using the developed model, we calculate the spectral dependences the dynamic conductivity of the optically pumped
graphene layer and bilayer associated with the interband and intraband transitions, estimate the pumping optical power required
for lasing, and demonstrate the feasibility of realization of such a laser.
The article is published in the original. 相似文献
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Nonlinear cylindrical magnetoacoustic perturbations in a plasma are considered in the framework of the two-liquid collisionless electromagnetic model. The method of power expansion in a small parameter in extended space-time coordinates is used to obtain the cylindrical Korteweg-de Vries equation that describes nonlinear radial cylindrical waves. An approximate solution to this equation has the form of a cylindrical magnetoacoustic compression soliton. 相似文献
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We performed a particle-in-cell (PIC) simulation of a vircator with counter electron beams in a cylindrical cavity with metal walls. Two pairs of counter-propagating superlimiting electron beams with different energy and current in each pair are injected along the cylinder axis. It is found that the electron charge in the cavity is formed as a sequence of pulses corresponding to slow accumulation and fast discharge. It is shown that the pulses are related to the characteristic dynamics of the squeezed beam state, the distributed virtual cathode. This regime can be used to generate anHF sequence of ultrawideband electromagnetic pulses. 相似文献
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State-of-the-art compact recirculating electron accelerators operating at intermediate energies (tens of MeV) are reviewed. The acceleration schemes implemented in the rhodotron, ridgetron, fantron, and cylindertron machines are discussed. Major accelerator components such as the electron guns, accelerating cavities, and bending magnets are described. The parameters of currently operating recirculating accelerators are tabulated, and applications of these accelerators in different processes of irradiation are exemplified. 相似文献
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A. A. Biryukov S. M. Nekorkin M. N. Kolesnikov T. S. Babushkina V. Ya. Aleshkin A. A. Dubinov 《Technical Physics》2011,56(7):1049-1052
Semiconductor lasers with an active region containing six quantum wells are investigated experimentally. The temperature dependences
of working characteristics (threshold current density, external differential quantum efficiency, and directional pattern)
are analyzed. Anomalous behavior of the temperature dependence of the threshold current and external differential quantum
efficiency, associated with a negative characteristic temperature and a decrease in the quantum efficiency of radiation upon
a decrease in temperature, is detected. A narrowing of the directional patterns in the plane perpendicular to the p-n junction upon an increase in temperature is revealed. 相似文献
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We propose a simple model for dynamics of the earlier detected metastable electrons oscillating near a virtual cathode. It was found that their behavior is similar to the dynamics of a reversed pendulum with a vibrating suspension, which was studied by P. L. Kapitsa. The number of metastable electrons is estimated using the method of large particles. 相似文献