动臂手动下降阀
boom manual lowering valve
滑阀的上下运动
up and down spool movement
水下运动目标
moving underwater targets
underwater moving target
水下运动目标搜索
searching for moving underwater target
下运动神经元综合征
Lower motor neuron syndrome
转速波动下降
The revolutions fluctuating decrease
自主水下运动平台
autonomous underwater vehicle
差异升降运动
differential uplifting-subsidence movement