1. Mechanical and Electrical Engineering College, Hainan University, Haikou 570228, Hainan, China
2. Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Science, Changchun 130033, Jilin, China
3. Key Laboratory of Tropical Biological Resources of Ministry of Education, Ocean College, Hainan University, Haikou 570228, Hainan, China
4. School of Mechanical Engineering, Yeungnam University, Gyongsan 712-719, Korea