Guan Yi-Jun, Sun Hong-Xiang, Yuan Shou-Qi, Ge Yong, Xia Jian-Ping. Propagation characteristics of laser-generated surface acoustic waves in composite plate with gradient changes of near-surface viscous moduliJ. Acta Physica Sinica, 2016, 65(22): 224201. DOI: 10.7498/aps.65.224201