短語詞組短語oscillation time period 脈動周期Proper oscillation period 固有振動周期period oscillation 周期振蕩long -period oscillation damping 長周期振動阻尼short -period oscillation 短周期振動;短周期振蕩year period oscillation 年周期振蕩longline effect period oscillation 長周期振蕩period of oscillation 振蕩周期;擺動周期 返回 oscillation period