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We study the linear and nonlinear properties of two-dimensional matter-wave pulses in disk-shaped superfluid Fermi gases.A Kadomtsev-Petviashvili I(KPI) solitary wave has been realized for superfluid Fermi gases in the limited cases of Bardeen-Cooper-Schrieffer(BCS) regime,Bose-Einstein condensate(BEC) regime,and unitarity regime.Onelump solution as well as one-line soliton solutions for the KPI equation are obtained,and two-line soliton solutions with the same amplitude are also studied in the limited cases.The dependence of the lump propagating velocity and the sound speed of two-dimensional superfluid Fermi gases on the interaction parameter are investigated for the limited cases of BEC and unitarity. 相似文献
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Small amplitude double layers in an electronegative dusty plasma with q-distributed electrons 下载免费PDF全文
The small amplitude dust ion-acoustic double layers in a collisionless four-component unmagnetized dusty plasma system containing nonextensive electrons, inertial negative ions, Maxwellian positive ions, and negatively charged static dust grains are investigated theoretically. Using the pseudo-potential approach and reductive perturbation method, an energy integral equation for the system has been derived and its solution in the form of double layers is obtained. The results appear that the existence regime of the double layer is very sensitive to the plasma parameters, e.g., electron nonextensivity,negative-to-positive ion number density ratio etc. It has been observed that for the selected set of parameters, the system supports rarefactive,(compressive) double layers depending upon the degree of nonextensivity of electrons. 相似文献
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In this paper, the Fisher equation is analysed. One of its travelling wave solution
is obtained by comparing it with KdV--Burgers (KdVB) equation. Its amplitude, width
and speed are investigated. The instability for the higher order disturbances to the
solution of the Fisher equation is also studied. 相似文献
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We study the nonlinear solitary wave solution under the transverse perturbations for a system of coupled nonlinear electrical transmission lines.In the continuum limit and suitably scaled coordinates,the voltage on the system is described by a modified Zakharov-Kuznetsov equation.The cut-off frequency of the growth rate for the solitary waves under transverse perturbations has been analytically obtained.It is in agreement with the cases P=1/2 and p=1 which have been studied previously. 相似文献
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用一维Frenkel-Kontorova模型,对相互接触的两个单原子分子链具有相对运动趋势时所产生的最大静摩擦力进行了研究.分别在相邻原子的距离与周期势场的周期比b/a为可公度(commensurate)、黄金分割(golden mean)、螺旋分割(spiral mean)三种情况下,描述了特殊垫底势力的振幅A与分子链静摩擦力的关系,在特殊垫底势力的作用下上层原子链弹性系数K对静摩擦力的影响.研究表明,垫底势力的形式对静摩擦力的大小有很重要的影响.
关键词:
Frenkel-Kontorova模型
静摩擦力 相似文献
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The effects of dust temperature and the dust charge variation in a dusty plasma with vortex—like ion distribution 下载免费PDF全文
By considering both the dust temperature and the dust charge variation in dusty plasma with vortex-like ion distribution, we obtained a modified Korteweg-de Vries equation. It indicates that the effect of dust charge variation can cause the one-dimensional soliton amplitude to become larger, and the dust temperature can cause the soliton amplitude to become larger as well. Moreover, as the dust temperature increases, the soliton amplitude will increase. 相似文献
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We study the Landau-Zener tunneling of a nonlinear two-level system
by applying a periodic modulation on its energy bias. We find that
the two levels are splitting at the zero points of the zero order
Bessel function for high-frequency modulation. Moreover, we obtain
the effective coupling constant between two levels at the zero
points of the zero order Bessel function by calculating the final
tunneling probability at these points. It seems that the effective
coupling constant can be regarded as the approximation of the higher
order Bessel function at these points. For the low-frequency
modulation, we find that the final tunneling probability is a
function of the interaction strength. For the weak inter-level
coupling case, we find that the final tunneling probability is more
disordered as the interaction strength becomes larger. 相似文献