In this paper, we construct a continuous positive periodic function
p(
t) such that the corresponding superlinear Duffing equation
$$x'' + a\left( x \right){x^{2n + 1}} + p\left( t \right){x^{2m + 1}} = 0,n + 2 \leqslant 2m + 1 < 2n + 1$$
possesses a solution which escapes to infinity in some finite time, and also has infinitely many subharmonic and quasi-periodic solutions, where the coefficient
a(
x) is an arbitrary positive smooth periodic function defined in the whole real axis.