Two sorts of echoes caused by the reradiation of elasticsurfacewave have been observed in experimentation: the radial surface backscattering wave and the longitudinal surface backscattering wave.
实验观测到两类由弹性表面波的再辐射产生的回波：径向表面反向散射波和纵向表面反向散射波。
2
The theory expresses the sound fields by a superposition of various surfaceelastic waves-circumferential waves and reveal the vibro-acoustic coupling mechanism in viewpoint of wave.
此理论将声场表示成各种表面弹性波-环绕波的再辐射的叠加，从波动的角度揭示声-振耦合机理。
3
For the piezoelectric crystal, not only a mechanical source distribution at the surface, but an electrical source distribution also can excite the elasticwave fields.