Guo-Ying Tang, Zhu-Ling Sun, Ru-Bin Jiang, Feng-Quan Li, Ming-Yuan Liu, Kun Liu, Xiu-Shu Qie. Characteristics and mechanism of a triggered lightning with two polarity reversals of charges transferred to ground [J]. Acta Physica Sinica, 2020, 69(18): 189201-1