Mr Min Yang successfully defended his PhD thesis on May 23th, 2020, offline even the coronav-19 was spreading worldwide. The oral examination committee includes Prof Xingang Liang (Chair, Tsinghua University), Prof Xiaodong Wang (North China Electric Power University), Prof Wei Wang (Pecking University), Prof Yuanyuan Duan (Tsinghua University) and Prof Bingyang Cao (Tsinghua University). Congratulations!