凯撒效应当材料受到外力或内应力时,其内部或表面产生缺陷的地方往往成为声源,发出较强的声波,就象地壳内部的震源一样;这产生的声波先在材料的内部向四方扩散传播,当到达表面后,再沿着表面向前传播。如果我们有一个能测量微小表面位移、速度或加速度的仪器,我们就可以测量这声波的特性,就如同地震仪侦测地球表面的地震波一样。假如我们有数个地震观测站,我们可以利用地震波到达时间的不同来确定地震的震中,进而可以了解地震的大小和频度分布,于是可以对地震活动性进行定量的描述和研究。采用同样的原理,我们可 Caesar effect When the material is subjected to external or internal stress, its internal or surface defects often become a source of sound, issued a strong sound waves, like the crust of the Earth’s source; the sound waves generated in the first spread to the Quartet Spread, when it reaches the surface, then spread along the surface. If we have an instrument that can measure small surface displacements, velocities, or accelerations, we can measure the characteristics of this sound wave just as seismometers detect seismic waves on the Earth’s surface. If we have several seismic stations, we can determine the epicenter of the earthquake by using the different arrival times of the seismic waves, and then we can understand the size and frequency distribution of the earthquake so that the seismic activity can be quantitatively described and studied. Using the same principle, we can