研究了$n$ -维分段光滑扰动微分系统
$ \begin{eqnarray*} \ \left\{\begin{array}{ll} \dot{x}_1=x_2+\varepsilon g^+_1({\bf x}),\\ \dot{x}_2=-x_1+\varepsilon g^+_2({\bf x}),\\ \dot{x}_3=\varepsilon g^+_3({\bf x}),\\ \cdots\\ \dot{x}_n=\varepsilon g^+_n({\bf x}),\\ \end{array}\right.x_1\geq0,\quad \quad \left\{\begin{array}{ll} \dot{x}_1=x_2+\varepsilon g^-_1({\bf x}),\\ \dot{x}_2=-x_1+\varepsilon g^-_2({\bf x}),\\ \dot{x}_3=\varepsilon g^-_3({\bf x}),\\ \cdots\\ \dot{x}_n=\varepsilon g^-_n({\bf x}),\\ \end{array}\right.x_1<0, \end{eqnarray*} $
其中${\bf x}=(x_1,x_2,\cdots,x_n)^T$, $0<\varepsilon\ll1$,且$g^\pm_i({\bf x})$, $i=1,2,\cdots,n$是关于${\bf x}$的$m$次实系数多项式.应用一阶Melnikov向量函数,得到了从其未扰动系统分支出周期轨个数的上界.