1. College of Mechanical and Electronic Engineering, Northwest A&F University; Yangling 712100 Shaanxi China
2. Department of Wood Science and Engineering; Oregon State University; Corvallis Oregon 97331
3. MOE Key Laboratory of Wooden Material Science and Application; Beijing Forestry University; Beijing 100083 China
4. Vietnam-Russian Vocation College N01; Xuan Hoa area283400 Vietnam