共查询到20条相似文献,搜索用时 15 毫秒
1.
Low frequency (in comparison to ion plasma frequency) ion-acoustic shocks and solitons in superdense electronpositron-ion quantum plasmas are studied. The quantum hydrodynamic model is used incorporating quantum Bohm forces and Fermi-Dirac statistical corrections to derive the deformed Korteweg de Vries-Burgers (dKdVB) equation in weakly nonlinear limit. The travelling wave solution of dKdVB equation is presented and results are discussed in different limits. It is found that shock height increases with increase of quantum pressure, positron concentration and dissipation. Further, it is seen that the width of soliton decreases with increase of quantum pressure 相似文献
2.
HUANG Feng LIU Yan-Hong WANG Long 《理论物理通讯》2005,44(6):1081-1086
The influence of the confining potential strength and temperature on the structures and dynamics of a two-dimensional (2D) dusty plasma system is investigated through molecular dynamic (MD) simulation. The circular symmetric confining potential leads to the nonuniform packing of particles, that is, an inner core with a hexagon lattice surrounded by a few outer circular shells. Under the appropriate confining potential and temperature, the particle trajectories on middle shells form a series of concentric and nested hexagons due to tangential movements of particles. Mean square displacement, self-diffusion constant, pair correlation function, and the nearest bond are used to characterize the structural and dynamical properties of the system. With the increase of the confining potential, the radial and tangential movements of particles have different behaviors. With the increase of temperature, the radial and tangential motions strengthen, particle trajectories gradually become disordered, and the system gradually changes from a crystal or liquid state to a gas state. 相似文献
3.
HUANG Feng LIU Yan-Hong WANG Long 《理论物理通讯》2005,44(12)
The influence of the confining potential strength and temperature on the structures and dynamics of a two-dimensional (2D) dusty plasma system is investigated through molecular dynamic (MD) simulation. The circular symmetric confining potential leads to the nonuniform packing of particles, that is, an inner core with a hexagon lattice surrounded by a few outer circular shells. Under the appropriate confining potential and temperature, the particle trajectories on middle shells form a series of concentric and nested hexagons due to tangential movements of particles.Mean square displacement, self-diffusion constant, pair correlation function, and the nearest bond are used to characterize the structural and dynamical properties of the system. With the increase of the confining potential, the radial and tangential movements of particles have different behaviors. With the increase of temperature, the radial and tangential motions strengthen, particle trajectories gradually become disordered, and the system gradually changes from a crystal or liquid state to a gas state. 相似文献
4.
Two important classes of quantum structures, namely orthomodular posets and orthomodular lattices, can be characterized in
a classical context, using notions like partial information and points of view. Using the formalism of representation systems,
we show that these quantum structures can be obtained by expressing conditions on the existence of particular points of view,
of particular ways to observe a system.
PACS: 02.70.Wz, 03.67.Lx. 相似文献
5.
量子阱非线性光学研究进展 总被引:1,自引:0,他引:1
综述了量子阱非线性光学领域近年来实验工作的进展,重点介绍了共振增强的二阶和三阶非线性效应、光折变效应、量子阱光调制器和IV族材料的非线性过程,指出该领域发展迅速,应用前景十分广阔。 相似文献
6.
7.
We discuss the Lindblad equation for the density matrix where the dissipation is linear in the position operator. We consider a potential which is a bounded perturbation of the harmonic oscillator. We show that the perturbation of the potential leads to an analytic perturbation of the Wigner distribution. Then the Wigner distribution of the quantum dissipative system tends (uniformly in time) to the classical phase space distribution of the classical dissipative system (if the initial distribution converges when 0). 相似文献
8.
By using the quantum magnetohydrodynamic model, the electrostatic waves in weakly magnetized quantum plasmas are investigated. The electrons are treated as a quantum and magnetized species, while the ions are classical unmagnetized ones. The general dispersion relations are derived. It is shown that, both the high frequency electron waves (Langmuire wave and upper-hybrid wave) and the low frequency ion acoustic wave can propagate when the plasmas are cold. 相似文献
9.
Shalini Bagchi Kasturi Roy Chowdhury A. P. Mishra A. Roy Chowdhury 《International Journal of Theoretical Physics》2009,48(4):1132-1141
Nonlinear excitation in self gravitating quantum dusty plasma is analysed from the viewpoint of perturbation theory. A plasma
configuration consisting of electron, ion and dust particles are treated by reductive perturbation theory, to deduce two coupled
modified KdV equations. The soliton like solutions of such coupled systems are obtained with the help of another multiple
scale perturbation theory. This leads to the variation of soliton amplitude and velocity due to the several interaction terms. 相似文献
10.
非线性简并光学参量放大系统的量子起伏 总被引:1,自引:1,他引:0
解析求解了P表象中考虑抽运吃空后的非线性含时简并光学参量放大系统获得压缩光所满足的福克尔-普朗克(Fokker-Planck)方程,并且计算了它在阈值附近及远离阈值的量子起伏。研究表明:若略去与η成正比的项,则通解很自然地过渡到线性近似解。计及与η成正比的项后,该解与Drummond等在阈值附近的微扰展开理论相比,基本相符。但在远离阈值处,微扰展开理论不适用,而该结果在阈值附近以及远离阈值的整个区域均是适用的。当μ→0压缩很小时,起伏趋近于真空起伏;而μ〉〉1,压缩增大时,趋近1/1+μ线性理论。 相似文献
11.
In this paper, the structural and single-particle motive properties of a two-dimensional dusty plasmas are investigated numerically by molecular dynamics simulation within the framework of a dissipative Yukawa model.The pair correlation function, the mean square displacement, the static structure factor, and the bond angle correlation function characterizing the structural properties, and the velocity autocorrelation function with Fourier spectrum function characterizing the single-particle motion have been calculated for different values of coupling constant Γ and viscous damping constant vf. The results show that the system will coagulate quickly with increasing viscous damping constant and coupling constant, and the critical value of friction parameter decreases with increasing the coupling constant in the system. 相似文献
12.
LIU Song-Fen HUANG Gui-Ling WANG Xin LIU Yan-Hong HU Bei-Lai WANG Long 《理论物理通讯》2006,46(6):1085-1090
In this paper, the structural and single-particle motive properties of a two-dimensional dusty plasmas are investigated numerically by molecular dynamics simulation within the framework of a dissipative Yukawa model. The pair correlation function, the mean square displacement, the static structure factor, and the bond angle correlation function characterizing the structural properties, and the velocity autocorrelation function with Fourier spectrum function characterizing the single-particle motion have been calculated for different values of coupling constant r and viscous damping constant vf. The results show that the system will coagulate quickly with increasing viscous damping constant and coupling constant, and the critical value of friction parameter decreases with increasing the coupling constant in the system. 相似文献
13.
I argue that the linearity of quantum mechanics is an emergent feature at the Planck scale, along with the manifold structure
of space-time. In this regime the usual causality violation objections to nonlinearity do not apply, and nonlinear effects
can be of comparable magnitude to the linear ones and still be highly suppressed at low energies. This can offer alternative
approaches to quantum gravity and to the evolution of the early universe.
PACS: 04.60.-m, 03.65.Ta 相似文献
14.
LIN Chang ZHANG Xiu-Lian 《理论物理通讯》2005,44(2):247-251
The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation. 相似文献
15.
LIN Chang ZHANG Xiu-Lian 《理论物理通讯》2005,44(8)
The nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation is analytically investigated by using the formally variable separation approach. New analytical solutions for the governing equation of this system have been obtained for dust acoustic waves in a dust plasma for the first time. We derive exact analytical expressions for the general case of the nonlinear dust acoustic waves in two-dimensional dust plasma with dust charge variation. 相似文献
16.
17.
The basic properties of the nonlinear propagation of the nonplanar(cylindrical and spherical) positronacoustic(PA) shock waves(SHWs) in an unmagnetized electron-positron-ion(e-p-i) plasma containing immobile positive ions,mobile cold positrons,and superthermal(kappa distributed) hot positrons and electrons are investigated both analytically and numerically.The modified Burgers equation(mBE) is derived by using the reductive perturbation method.The basic features of PA SHWs are significantly modified by the cold positron kinematic viscosity(η),superthermal parameter of electrons(κ_e),superthermal parameter of hot positrons(κ_p),the ratio of the electron temperature to hot positron temperature(σ),the ratio of the electron number density to cold positron number density(μ_e),and the ratio of the hot positron number density to cold positron number density(μ_(ph)).This study could be useful to identify the basic properties of nonlinear electrostatic disturbances in dissipative space and laboratory plasmas. 相似文献
18.
19.
BAO Jing-Dong 《理论物理通讯》2005,44(10)
The coupling between system and reservoir is considered to be linear in the coordinates of the bath but nonlinear in the system‘s coordinate. A dissipative threshold is observed at finite temperatures due to nonlinear dissipation. The quantum decay rate of a metastable state including higher-order expanded terms of the coupling form function is proposed, which can be strongly decreased at finite temperatures when the quantum dissipative threshold is added to the saddle point of the potential. 相似文献
20.
BAO Jing-Dong 《理论物理通讯》2005,44(4):697-700
The coupling between system and reservoir is considered to be linear in the coordinates of the bath but nonlinear in the system's coordinate. A dissipative threshold is observed at finite temperatures due to nonlinear dissipation. The quantum decay rate of a metastable state including higher-order expanded terms of the coupling form function is proposed, which can be strongly decreased at finite temperatures when the quantum dissipative threshold is added to the saddle point of the potential. 相似文献