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

In this paper, the logarithmic perturbation scheme for the central potential field is investigated.

对中心势场的对数微扰论方法作了进一步探讨。

youdao

Using the perturbation method we have got the fourth order of approximation of the velocity potential to the problem.

运用摄动方法，给出了速度势的四阶近似，然后得到了圆柱表面的无量纲的压力系数和阻力系数。

youdao

To deal with the potential problem that some farmers might get disillusioned and withdraw early - creating perturbation - each group will have to deposit enough money into a bank account in advance to cover the entire cost of a four-year operation.

BBC: Badger cull heads for further consultation