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1.
M. Mehdipoor 《Astrophysics and Space Science》2012,338(1):73-79
Korteweg-de-Vries-Burger (K-dVB) equation is derived for ion acoustic shock waves in electron-positron-ion plasmas. Electrons
and positrons are considered superthermal and are effectively modeled by a kappa distribution in which ions are as cold fluid.
The analytical traveling wave solutions of the K-dVB equation investigated, through the (G′/G)-expansion method. These traveling wave solutions are expressed by hyperbolic function, trigonometric functions are rational
functions. When the parameters are taken special values, the shock waves are derived from the traveling waves. It is observed
that the amplitude ion acoustic shock waves increase as spectral index κ and kinematic viscosity η
i,0 increases in which with increasing positron density β and electron temperature σ the shock amplitude decreases. Also, numerically the effect different parameters on the nonlinearity A and dispersive B terms and wave velocity V investigated. 相似文献
2.
Theoretical investigation is carried out to understand the dynamics and stability of three dimensional ion solitary waves propagating in dense plasma comprising of ultra-relativistic degenerate electrons and positrons and warm ions. A linear dispersion relation is derived which shows a strong dependence of wave on positron concentration (through the change of density balance) and ion-to-degenerate electron temperature ratio. A nonlinear Kadomtsev-Petviashvili equation is derived by employing the reductive perturbation technique and solved analytically and the conditions for existence of stable solitary waves are found. The analysis reveals that only compressive solitary waves exist in the system. Effects of the change of density balance and Fermi temperature ratios are studied in detail, both analytically and numerically. Furthermore, the conditions for stable solitary waves are discussed by using energy consideration method. The numerical results are also presented by using the parameters consistent with the degenerate and ultrarelativistic astrophysical plasmas. 相似文献
3.
The propagation and the head—on collision of nonlinear dust—acoustic solitary waves (DASWs) in dusty plasmas consisting of
electrons, ions and negative as well as positive dust particles are investigated. Applying an extended Poincaré-Lighthill-Kuo
(PLK) method, Kortwege-de Vries equations and analytical phase shifts after the head-on collision of two DASWs in dusty plasmas
are obtained. Analytically and numerically, the relevance of the phase shifts and trajectories to the positive-to-negative
dust number density ratio, the ratio of the ion number density to negative dust number density, negative-to-positive dust
particle mass ratio, and the ion-to-electron temperature ratio effects is explicitly demonstrated. Moreover, the current findings
are applied to different regions of space, viz. cometary tails, mesosphere, Jupiter’s magnetosphere. 相似文献
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5.
The moment method is used to solve the radiative transfer problem in an anisotropic scattering plane medium with arbitrary space-dependent albedo(x). The results are compared with those obtained recently by Cengel and Özisik. 相似文献