1. College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao, People’s Republic of China
2. National Engineering Research Center for Equipment and Technology of C.S.R., YanShan University, QinHuangdao, People’s Republic of China
3. College of Mechanical and Electrical Engineering, Nanjing Forestry University, Nanjing, People’s Republic of China