中文摘要：

采用局域非简谐近似（LAA）和旋转波近似（RWA），讨论一维β-FPU双原子链中的能隙呼吸子．在驻波边界条件下数值求解一维β-FPU双原子链品格振动的运动方程组，得到不同耦合系数，不同非线性系数以及不同原子质量比情况下的能隙呼吸子，并进行了分析和讨论．无论是在硬非线性还是软非线性情况下，呼吸子解都是随着耦合系数的增大，其空间扩展范围也随之增大；非线性作用越强，能隙呼吸子局域化越强；随着原子质量比的增大，能隙呼吸子在空间越来越局域；软非线性情况下的呼吸子随不同参数发生变化的程度，要比硬非线性的呼吸子明显得多．

英文摘要：

Using local anharmonicity approximation （LAA） and rotating-wave approximation （RWA）, discrete gap breathers （DGBS） in one-dimensional diatomic β-FPU chain were investigated. Under standing wave boundary conditions, gap breather solutions of complete motion equations were calculated numerically. By numerical calculation method, GB profiles were obtained under various coupling coefficient, nonlinearity coefficient and atomic mass ratio. Whether quartic nonlinearity effect was soft or hard, gap breathers＇ spatial field was expanded with increasing coupling coefficient. With greater quartic nonlinearity effect DGB localization also became stronger. At the meantime, with higher atomic mass ratio, DGB localization also became stronger. Degree of DGB change became more obvious with soft-nonlinearity than with hardnonlinearity.