The Hamiltonian of sodium atom is reduced by using screening Coulomb potential, and the energy levels of sodium atom are calculated by means of twofold perturbation.

用屏蔽库仑势简化了钠原子的哈密顿，用两次微扰法计算了钠原子的能量，结果与实验值符合得较好。

youdao

Based on the method of small parameters perturbation of 2nd order, the stochastic functional of potential energy for structures with stochastic stiffness under stochastic stimulus is derived.

利用小参数摄动法，建立了随机结构在随机激励下的二阶摄动随机势能泛函。

youdao

Based on the method of small parameters perturbation of 2nd order, the stochastic functional of potential energy for structures with stochastic stiffness under stochastic stimulus is derived.

利用小参数摄动法，建立了随机结构在随机激励下的二阶摄动随机势能泛函。

youdao