中文摘要：

把直角的基础基于双性人的途径，我们执行为开的系统的一个类的扩大与出去的波浪边界条件由波浪方程描述了的伪正常模式(QNM ) 。为如此的一个 non-Hermitian 系统，特徵函数不安扩大和格林功能方法，为关上的量系统基于 Hermitian Hamiltonian 的直角的特徵向量，能以双性人被概括直角的基础， H 和它的伴随海角 H ^†的特徵函数的二个集合。为复杂频率的时间无关的不安理论能也被开发。

英文摘要：

Based on the approach of biorthogonal basis, we carry out the quasinormal modes （QNMs） expansions for a class of open systems described by the wave equation with outgoing wave boundary conditions. For such a non-Hermitian system, the eigenfunction perturbation expansions and Green function method, which are based on the orthogonal eigenvectors of the Hermitian Hamiltonian for the dosed quantum system, can be generalized in terms of the biorthogonal basis, the two sets of eigenfunctions of H and its adjointness H . The time-independent perturbation theory for the complex frequencies can be also developed.