1. Institute of Hybrid Materials National Center of International Research for Hybrid Materials Technology National Base of International Science & Technology Cooperation College of Materials Science and Engineering Qingdao University Qingdao 266071 P. R. China
2. School of Information Science and Engineering Shandong University Qingdao 266237 P. R. China
3. College of Electronic information Qingdao University Qingdao 266071 P. R. China
4. Department of Chemical and Biological Engineering Colorado State University Fort Collins CO 80523 USA