1. Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, College of Energy, Xiamen University, Xiamen 361102, P. R. China
2. College of Forestry, Hebei Agricultural University, Baoding 071001, P. R. China
3. Fujian Engineering and Research Center of Clean and High-Valued Technologies for Biomass, Xiamen 361102, P. R. China