本文研究在不连续介质中波动方程的本征模及其背后的物理机制，探讨波在界面的反射和透射规律，揭示了在特定参量条件下机械波发生全透射的效应，这一效应可能会在吸波材料中有应用价值.

The paper investigates eigen modes of the wave equation in discontinuous media and explores the underlying physical mechanism. We also study the reflection and transmission of wave at the interface and reveal a full transmission effect under specific physical conditions. This effect may find applications in wave-absorptive materials.