运用Schauder不动点定理研究了二阶非自治奇异耦合系统{x″+a1(t)x=f1(t,y(t))+e1(t),y″+a2(t)y=f2(t,x(t))+e2(t)正周期解的存在性,其中a:i,ei∈L1(R/TZ,R),fi∈Car(R/TZ×(0,∞),R),即fi|[0,T][0,T]×(0,∞)→R是L1-Carathéodory函数(i=1,2),并且f1,f2分别在y=0,x=0处允许有奇性。在扰动项积分值符号同正、同负和异号的情况下,分别获得了该奇异耦合系统存在正周期解的条件。
Using Schauders fixed point theorem,we study the existence of positive periodic solutions for second order non-autonomous singular coupled systems{x″ + a1( t) x = f1( t,y( t)) + e1( t),y″ + a2( t) y = f2( t,x( t)) + e2( t),where ai,ei∈ L1( R/TZ,R),fi∈ Car( R/TZ ×( 0,∞),R),that is,fi|[0,T]: [0,T] ×( 0,∞)→ R are L1-Carathéodory functions( i = 1,2),and f1,f2 may be singular at y = 0,x = 0,respectively. The existence of positive periodic solutions for the singular coupled systems are obtained under the conditions that the signs of integral disturbance terms are positive,or negative,or different.