The PmP waveform data obtained from a deep seismic sounding profile, which ran through Zhangbei seismic region, were processed by means of both seismic wave complexity coefficient and frequency spectrum analysis methods, and the complexity characteristics of crust-mantle boundary beneath the studied area and its adjacent region were determined.

For an ancient stable block, the Moho complexity coefficient is small, which reflects the feature of first order discontinuous interface.

Research on heat integrated complex distillation system synthesis;