1. Lecturer, Faculty of Mechanical and Electrical Engineering, Yunnan Agricultural Univ., Kunming 650201, China.
2. Postgraduat Student, Faculty of Mechanical and Electrical Engineering, Yunnan Agricultural Univ., Kunming 650201, China.
3. Professor, Faculty of Mechanical and Electrical Engineering, Yunnan Agricultural Univ., Kunming 650201, China.
4. Lecturer, Faculty of Mechanical and Electrical Engineering, Yunnan Agricultural Univ., Kunming 650201, China (corresponding author).