1. School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu, People's Republic of China
2. Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu, People's Republic of China
3. School of Science, Shandong Jianzhu University, Jinan, People's Republic of China
4. College of Computer Science, Sichuan University, Chengdu, People's Republic of China