1. School of Materials Science and Engineering Hebei University of Technology Tianjin 300401 P. R. China
2. Key Laboratory of Hebei Province for Molecular Biophysics Institute of Biophysics School of Science Hebei University of Technology Tianjin 300401 P. R. China
3. School of Chemical Engineering and Technology Hebei University of Technology Tianjin 300132 P. R. China