“…Exact solutions can make people understand deeply the physical mechanism of the natural phenomena described by NLEs. Some methods for constructing explicit exact solutions of NLEs, such as the inverse scattering method [1-4, 18, 19], Hirota method [13,20], Bäcklund transformation [21][22][23], and Darboux transformation (DT) [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41], have been developed. Among them, the DT based on the Lax pair is an algebraic method which is an effective tool to solve the Lax integrable NLEs.…”