Sometimes we would also try to hit the hubcaps of passing cars and, when we succeeded, it made a loud pinging noise. 有时我们还砸过往车辆的毂盖,每当击中了就会响亮地发出砰的一声。
The main noise source in cutting is the noise from the work piece hit by the teeth of the saw, which concludes stable state pulsed excitation noise, vibration noise, frictional noise and aerodynamic noise. 负载噪声主要是由圆锯片击打工件,圆锯片与工件相互作用产生的稳态脉冲激励噪声、振动噪声、摩擦噪声和空气动力性噪声组成。
The flour mill noise origin mainly has the mechanical noise, the material and the machinery hit and the friction and the air current noise. 面粉厂噪声的来源主要有机械噪声、物料与机械的撞击和摩擦及气流噪声。