1. Division of Graduate, Harbin University of Science and Technology, Harbin 150080, P. R. China
2. Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin 150001, P. R. China
3. Forest Woodworking Machinery Research and Development Center, Northeast Forestry University, Harbin 150040, P. R. China
4. School of Mechanical Engineering, Harbin University of Science and Technology, Harbin 150080, P. R. China