We have analyzed the narrow components in the positron annihilation angular correlation spectra of stage-2 graphite-potassium intercalation by using the topological charge density of the skyrmion-like soliton, and have discussed the energy loss rate for low-energy positrons through "topological quasi-positronium" effect.

We have discussed the behaviour of adsorbed hydrogen on Ni(111) surface from the viewpoint of the topological quasi-hydrogen model. The anomalous hydrogen liquid phase and hydrogen-glass phase on Ni(111) surface are proposed. The soliton-catalytic effect of hydrogens on Ni(111) surface is suggested.