中文摘要：

扩大 Jacobian 椭圆形的功能扩大方法被介绍并且适用解决联合 ZK 方程和弱长的非线性的波浪在液体系统建模的描述二的联合 KP 方程。二倍地周期的旅行波浪答案的许多类型被获得。在限制条件下面，这些答案被简化为独居的波浪答案。

英文摘要：

The extended Jacobian elliptic function expansion method is introduced and applied to solve the coupled ZK equations and the coupled KP equations describing two weakly long nonlinear wave models in fluid system. Many types of doubly periodic traveling wave solutions are obtained. Under limiting conditions these solutions are reduced into solitary wave solutions.