1. MOE Key Laboratory of Resources and Environmental System Optimization
2. College of Environmental Science and Engineering
3. North China Electric Power University
4. Beijing 102206
5. P.R. China
6. NAAM Research Group
7. Department of Mathematics
8. Faculty of Science
9. King Abdulaziz University
10. Jeddah 21589
11. School of Public Health
12. Texas A&M University
13. USA