排序方式: 共有26条查询结果,搜索用时 15 毫秒
1.
2.
In the present paper, the effect of plasma absorption on lattice waves in 2D hexagonal dust crystals is investigated. The dispersion relations with the effect of plasma absorption are derived.It is found that the temperature effect(electron-to-ion temperature ratio τ) enhances the frequency of the dust lattice waves, while the spatial effect(dimensionless Debye shielding parameter k) weakens the frequency of the dust lattice waves. In addition, the system stabilities under the conditions of plasma absorption are studied. It is found that the temperature effect narrows the range of instability, while the spatial effect extends this range. And the range of instability is calculated, i.e. the system will always in the stable state regardless of the value of k when τ??3.5. However, the system will be unstable when τ?=?1 and k 4.1. 相似文献
3.
采用基于密度泛函理论的第一性原理方法研究了钇的含量对W-Y二元合金力学性质的影响,精确计算了W_(1-x)Y_x(x=0.0625,0.125,0.25,0.5)合金的力学常数,并对其力学特性进行分析。结果表明,W-Y合金的弹性常数、体模量、杨氏模量以及剪切模量随Y含量(原子分数)的增加而成非单调性减小,表明Y对W材料的合金化降低了材料的机械强度。然而,基于力学特性B/G、泊松比ν和柯西压力C'等分析,Y的合金化对W的延展性和韧性有明显的提高。当Y含量x为0.25时,可有效改善W-Y合金的延展性和抗变形能力。通过态密度分析,W-Y合金的金属性随Y含量的增加先减弱而后增强。 相似文献
4.
5.
6.
本文用Melinkov方法研究了描述气候演变的强迫Saltzman振子周期分叉及混沌运动,得到了系统产生混沌现象的临界值。 相似文献
7.
The wake bubble expansion and contraction by adding a dense-plasma wall in the background plasma during the mode transition from laser wakefield to plasma wakefield acceleration is investigated by particle-in-cell simulations.The electrons are injected continuously into the cavity until the lateral bubble size equals the inner diameter of the wall.The injected electron bunch from the laser wakefield acceleration(LWFA) scheme is quasi phase-stably accelerated forward because of the longitudinal contraction of the bubble.After the laser pulse is depleted completely,the electron bunch generated from the LWFA scheme drives a plasma wakefield.The electrons remaining in the channel are trapped and accelerated by the plasma wakefield.Ultimately,two energetic electron bunches with a narrow energy spread and low emittance are obtained. 相似文献
8.
9.
Kerr介质中受激三能级原子的场熵演化特性 总被引:3,自引:2,他引:1
本文研究了在Kerr介质中单模相干场与“Λ”型三能级原子相互作用的场熵演化规律,讨论了Kerr介质及初始场的平均光子数(初始场强)对场熵演化的影响。研究结果表明:初始场的平均光子数-↑n影响了场熵演化的周期性,在初始场强-↑n不太大(约-↑n<40)的情况下,随着-↑n的增加,场熵演化曲线的均值不断增大,光场与原子的关联程度增强;而在强场条件下(约-↑n>40),初始场强-↑n的增加将导致光场与原子的关联程度逐渐减弱直至脱耦。Kerr介质强度系数μ同样影响着场熵演化的周期性,随着μ的增大,场熵演化曲线的Rabi振荡频率明显变快,而其最大值却不断减小,这表明:场熵敏感于Kerr介质的非线性相互作用,非线性Kerr介质的存在会削弱场与原子的相互作用。 相似文献
10.
Kerr介质中双原子与光场相互作用的场熵演化 总被引:1,自引:0,他引:1
利用全量子化理论,研究了Kerr介质中耦合二能级双原子与单模光场相互作用的场熵演化规律。结果表明:Kerr介质和原子间的相互作用都影响着场熵演化的周期性,并使光场与原子的关联程度减弱;初始场强n^-同样影响着场熵演化的周期性,且随着初始场强n^-的增加,光场与原子的关联程度先增强后减弱。 相似文献