1. School of Materials and Chemical Engineering, Hunan City University, Yiyang, Hunan, China
2. Department of Nursing, Yiyang Medical College, Yiyang, Hunan, China
3. College of Forestry, Northwest A & F University, Yangling, Shaanxi, China
4. Hunan Research Center of Engineering Technology for Utilization of Environmental and Resources Plant, Central South University of Forestry and Technology, Changsha, Hunan, China