superimposition

n.叠印；重叠

Future shock arises from the superimposition of a new culture on an old one. 未来冲击来自新文化与旧文化的重叠。

The superimposition method adds a signal at its resonance frequency with a signal at the subharmonic frequency. 本研究并提出两类波形以有效诱发穴蚀效应，分别为串接法及重叠法。