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Том 71, № 6 (2016)
- Год: 2016
- Статей: 5
- URL: https://journals.rcsi.science/0027-1349/issue/view/10039
Physics of Earth, Atmosphere, and Hydrosphere (Review)
Numerical tsunami modeling and the bottom relief
Аннотация
The effect of the quality of bathymetric data on the accuracy of tsunami-wave field calculation is considered. A review of the history of the numerical tsunami modeling development is presented. Particular emphasis is made on the World Ocean bottom models. It is shown that the modern digital bathymetry maps, for example, GEBCO, do not adequately simulate the sea bottom in numerical models of wave propagation, leading to considerable errors in estimating the maximum tsunami run-ups on the coast.
527-536
Radiophysucs, Electronics, Acoustics
On the influence of the electron-velocity spread in a beam on the mechanism of Cherenkov beam–plasma interaction
Аннотация
The instability of an electron beam in cold plasma is considered in the linear potential approximation with different velocity-distribution functions of beam electrons. It is demonstrated that the mechanism of beam instability in plasma changes as the electron-velocity spread is increased: the hydrodynamic single-particle instability mode evolves into the hydrodynamic collective mode or the single-particle kinetic one. Instability growth rates in different modes are determined analytically and numerically.
537-544
Condensed Matter Physics
The effects of two-dimensional bifurcations and quantum beats in a system of combined atomic force and scanning tunneling microscopes with quantum dots
Аннотация
The field and temperature dependence of the probability of two-dimensional dissipative tunneling is studied in the framework of one-instanton approximation for a model double-well oscillator potential in an external electric field at finite temperature with account for the influence of two local phonon modes for quantum dots in a system of a combined atomic force and a scanning tunneling microscope. It is demonstrated that in the mode of synchronous parallel transfer of tunneling particles from the cantilever tip to the quantum dot the two local phonon modes result in the occurrence of two stable peaks in the curve of the 2D dissipative tunneling probability as a function of the field. Qualitative comparison of the theoretical curve in the limit of weak dissociation and the experimental current–voltage characteristic for quantum dots that grow from colloidal gold under a cantilever tip at the initial stage of quantum-dot formation when the quantum dot size does not exceed 10 nm is performed. It is established that one of the two stable peaks that correspond to interaction of tunneling particles with two local phonon modes in the temperature dependence of the 2D dissipative tunneling probability can be split in two, which corresponds to the tunneling channel interference mechanism. It is found that the theoretically predicted and experimentally observed mode of quantum beats occurs near the bifurcation point.
545-555
Biophysics and Medical Physics
Slow variations of the electroconductivity of distilled water
Аннотация
The conductivity of distilled water with a slow change in temperature has been measured experimentally and studied. Periodic variations in the electrical conductivity of water have been found, which are observed at the rate of temperature change dT/dt < 0.1 K/h. The periods were longer than 24 h; the amplitudes of the variation ranged from +2.7% to–2.3%. The possible causes of the observed phenomena are discussed.
556-561
Autowave self-organization in heterogeneous natural–anthropogenic ecosystems
Аннотация
This article considers the spatio–temporal model of natural–anthropegenic ecosystems as a conjugated active media that takes the heterogeneity of anthropogenic and natural factors into account. The approach aims to identify the threshold values of the control parameters. The theoretical basis of the system analysis of the sustainability of the ecosystems is synergistic data on autowave self-organization in active media. The mathematical model is based on the modified FitzHugh–Nagumo system of equations.
562-568