1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing; Wuhan University of Technology; Luoshi Road 122 Wuhan 430070 P. R. China
2. Department of Physics; Faculty of Science; King Abdulaziz University; Jeddah 21589 Saudi Arabia
3. Department of Science and Environmental Studies and Center for Education in Environmental Sustainability; The Hong Kong Institute of Education; Tai Po N. T. Hong Kong P. R. China