短語詞組短語drill string longitudinal vibration 鑽柱的縱曏振動string g vibration 弦振動string free vibration 弦自由振動drill string lateral vibration 鑽柱橫曏振動drill string vertical vibration 鑽柱縱曏振動drill string torsional vibration 鑽柱的扭轉(zhuǎn)振動piano string vibration 鋼琴弦振動string vibration equation 弦振動方程 返回 string vibration