有限体系能量耗散运动的功率谱分析

研究了有限的多自由度耦合哈密顿系统能量耗散过程的动力学问题. 通过数值模拟，实现有关自由度的能量耗散过程，采用功率谱方法研究有关系统运动中的坐标q(t)或动量p(t)的演化过程. 结果发现：在有关系统的能量耗散过程中，有关自由度运动的频率成分向高频和低频方向都有明显展宽，随着无关系统自由度增多，展宽明显增加；低频成分比较稳定，高频成分随着时间的演变逐渐减少. 关键词： 有限系统 能量耗散 有关自由度 功率谱

Spectrum analysis on dissipative motion in finite systems

Dynamical problems about energy dissipation in a finite multi-degree of freedom Hamiltonian system are studied. The energy dissipation in the relevant system is realized by numerical simulation. By employing power spectrum analysis on q(t) or p(t) of the motion in the relevant system, it is found that during the dissipative process, distribution of the power spectral density about the motion extends to both lower and higher frequencies. The more irrelevant degrees of freedom are, the broader the distribution extends. Higher frequencies decrease as time evolves but there are no remarkable changes for lower frequency components.