1. School of Electrical and Power Engineering, China University of Mining and Technology, Xuzhou 221116, P. R. China
2. Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
3. Joint Institute for Biological Sciences, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, P. R. China