In this work we studied the behavior of hydrogen atom under different potential well and found that with decreasing the distance between the electron and proton, the more multiple interaction terms start to take effect and the potential well becomes more and more sensitive to the distance between the electron and proton. Based on these results, the potential well for the neutron decaying is determined. Furthermore, the general topics, such as the origin of nuclear energy, the fundamental forces in the nature and the matter with negative mass, also are discussed. At the end of this work, the duality model of our universe is put forth.