On the Number of Limit Cycles of a Piecewise Quadratic Near-Hamiltonian System

Figure 2

Possible portraits of (1) with two saddles and a generalized closed orbit.

(a) ,

(b) ,

(c) ,

(d) ,  ,  

(e) ,  ,  

(f) ,  ,  

(g) ,

(h) ,

(i) ,