1. Southwest Forestry University; Kunming 650224 Yunnan People's Republic of China
2. College of Wood Science and Technology; Nanjing Forestry University; Nanjing 210037 Jiangsu People's Republic of China
3. Institute of Scientific and Industrial Research; Osaka University; Ibaraki 565-0047 Osaka Japan
4. School of Engineering; Zhejiang A&F University; Lin'an 311300 People's Republic of China