The angular difference between the astronomical axis and the axis of figure called a "nutation" causes an earth orbit al spirical oscillation known as the famous chandler "wobble".

在天文学轴和形状轴之间的角度差称做“章动”，引起地球轨道螺旋摆动，就是著名的卡南德尔“摆动”。

youdao

Based on the character of off-axis and multi-pass amplification systems, the possibilities are analyzed that some part of the line could form optical oscillator and occur self-excitation oscillation.

根据离轴多程放大系统的光路特点，对产生谐振腔最可能的光路部分进行了自激振荡形成条件的分析，根据分析结果并结合实际情况采取了一些抑制自激振荡的措施。

youdao