1. Department of Biology and Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon,
Hong Kong S.A.R., P. R. China
2. Department of Physics, Anhui Normal University, Wuhu, Anhui 241000, P. R.
China
3. Department of Science
and Environmental
Studies, Faculty of Liberal Arts and Social Sciences, The Hong Kong Institute of Education, Tai Po, Hong
Kong S.A.R., P. R. China