of;
Applied;
Mathematics,;
Chengdu;
University;
of;
Information;
Technology,;
Sichuan;
610225,;
P.;
R.;
China;
of;
Mathematics;
and;
Finance,;
Fuyang;
Teachers;
College,;
Anhui;
236041,;
P.;
R.;
China;
of;
Mathematics,;
East;
China;
Normal;
University,;
Shanghai;
200062,;
P.;
R.;
China;