We propose a new concept,the centre of energy,to study energy diffusion and heat conduction in a one-dimensional hard-point model.For the diatom model,we find an anomalous energy diffusion as x2 ～ tβ with β = 1.33,which is independent of initial condition and mass rate.The present model can be viewed as the model composed by independent quasi-particles,the centre of energy.In this way,heat current can be calculated.Based on the theory of dynamic billiard,the divergent exponent of heat conductivity is estimated to be α = 0.33,which is confirmed by a simple numerical calculation.
