Zhentong Gao, an academician of the China Academy of Sciences, is an expert in metal structural fatigue. Before retiring, he worked as a professor at Beihang University, China, where his research focused on material fatigue performance and metal structural fatigue. Jiajin Xu is a researcher specializing in the fields of semiconductor, laser physics, nonlinear optics, and computational physics. He worked as a visiting scholar at the Optical Research Center, the University of Arizona in the US between 1988 and 1991.