基于双参数微扰法，结合双重微扰方案，对类锂原子低激发态1s2ns (n=3,4,5)的能量进行了计算.所得结果与实验值吻合，相对误差小于0.8%，并发现在这些激发态中电子仍可看作处于特定的圆轨道，呼应了玻尔理论中的定态假设；随着体系激发态变高，内层电子的有效核电荷数基本不变，外层电子的有效核电荷数逐渐降低.这些研究加深了对原子中与电子相关效应的认识.

By using the double-parameter perturbation method combined with a double-fold perturbation scheme, the energy levels for the low-lying excited states 1s2ns (n=3,4,5) of lithium-like atoms are calculated. The calculated results are in well agreement with experiment within a relative error of 0.8%. It is found that the electron can be regarded as moving in a circular orbit, corresponding to the assumption of steady state in Bohr theory. Moreover, it is shown that with the increase of the excited state of atom, the effective charge of inner electron remains largely the same, but the effective charge of the outer electron of the atom decreases. These findings would deepen our understanding of the electron related effects in atoms.