Department;
of;
Mathematics,;
Yibin;
University,;
Yibin;
644007,;
Sichuan;
Province,;
P.;
R.;
China;
Department;
of;
Mathematics;
and;
Computer;
Science,;
Amirkabir;
University;
of;
Technology,;
424;
Hafez;
Avenue,;
Tehran;
15914,;
Iran;
Volterra积分方程; 内积空间; 直觉; 应用; 固定点; 定理;