机译:
College of Mathematics Sichuan University Chengdu 610064 China;
College of Mathematics Sichuan University Chengdu 610064 China;
College of Mathematics Sichuan University Chengdu 610064 China;
College of Mathematics Sichuan University Chengdu 610064 China;
College of Aeronautics and Astronautics Sichuan University Chengdu 610064 China;