地极移动的非线性动力机制

用非线性动力学原理和非线性振动方法，结合Chandler摆动的时间序列反演，证实了Chandler摆动的衰减能量是由周年激发的非线性共振所补充的．由高布锡归算的ILS参数，按共振激发模型反演出的Chandler摆动衰减指数和频率品质因数等结果，符合已有的大量基本结论，反演出的非齐次项的强迫频率基本都在周年频率的周围．非线性共振模型还表明，Chandler频率的不稳定性是由于存在频率转换和漂移，摆动振幅的不稳定性是由于存在共振跳跃，非线性的存在还将引出组合共振频率．同时用推广的最小公倍数证实和频差频的存在，提供了非整数的最小公倍数算法，为数论的非线性推广和在天文中的应用提供了工具．

A NONLINEAR DYNAMICAL MECHANISM OF POLAR MOTION

Based on the principle of nonlinear mechanics and the method of nonlinear oscillations, we have proposed a model of resonance excitation as a nonlinear dynamical mechanism of polar motion. By comparison with the time series inverting of the Chandler wobber, it is shown that the decreasing energy of the Chandler wobber may be compensated by the nonlinear resonance of annual excitation. Then,the calculated parameters of ILS agree with the fundamental results of attenuated index and the quality factors of the inverted Chandler wobber from this resonance excitational model, and the forced frequencies of inverting nonhomogeneous terms are almost close to the annual frequency.Furthermore, the nonlinear resonance model also shows that the instability of Chandler frequencies may be caused by the existence of frequency alternation and shift.The instability of wobber amplitudes may be due to the existence of resonance jumping. The existence of nonlinear terms may introduce combined frequencies in polar motion.