[Guo, Shihui] Nanyang Inst Technol, Sch Civil Engn, Nanyang 473000, Peoples R China.
[Li, Genquan; Zhang, Yu; Wang, Ping] Nanyang Normal Univ, Dept Phys, Nanyang 473061, Peoples R China.
[Tang, Huang] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.
[Dai, Wei] Hubei Univ Educ, Dept Phys & Mech & Elect Engn, Wuhan 430205, Peoples R China.
[Bi, Jie] China Univ Geosci Wuhan, Sch Math & Phys, Wuhan 430074, Peoples R China.