Modelling atom/solid-surface inelastic collisions are a longstanding problem that has inspired theoretical and experimental interests.[1-3] Various models have been presented to reveal the underlying physical principles.[4-6] In these models,the solid surface is often simplified as a one-dimensional semiinfinite coupled-harmonic-oscillator chain,usually referred to as the Zwanzig model (or Rubin model).[7]This assumption provides an exact but formal procedure for eliminating irrelevant environmental variables and leads to a generalized Langevin equation (GLE) for the variable of interest.In recent years,due to its rationality and solvability,this model has been extended and widely applied to explain a variety of phenomena in physics,chemistry,engineering,and biology,such as atom/solid scattering,[8] lattice vibrations,[9,10] heat conduction,[11,12] and stochastic resonance.[13] Indeed,the size of a realistic bath environment is usually not too large,and the chain with a finite oscillator number can be regarded as a heat bath here,which presents unique features and leads to the results which are not usual for cases of an ideal infinite bath.