唤俊在武汉开上巡演了

Using the centre operator and the initial mechanical momentum operator, four kinds of raising and lowering operators of a Landau system (planar charged particle moving in a uniform magnetic field) were derived and corresponding selection rules and conserved quantum number were discussed.

(Ag,Au)/Si nanocomposite films were deposited using the rf co-sputtering method. The absorption coefficient of Ag/Si nanocomposite film was calculated based on the Maxwell-Garnett theory and differential effective medium(DEM) theory;the experimental results of spectra agreed with the DEM theory.And the possible microstructure and the reason why the plasma resonance absorption peaks were broadened have been discussed.