1. Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China, Fax: +852‐2358‐1594, http://www‐chem.ust.hk/Faculty%20staff/leung/content.htm
2. Department of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
3. Department of Applied Chemistry, School of Petrochemical Engineering, Changzhou University, Jiangsu 213164, P. R. China