Time-dependent self-diffusion coefficients and magnetization attenuation of liquid with surface relaxation in porous media in an infinitely long cylinder are calculated with Monte Carlo random walk method.Relationship between parameters of NMR relaxation and random walk is obtained.In fast-diffusion area, magnetization of nuclear spins attenuates exponentially,and self-diffusion coefficients are independent of surface relaxivity within short diffusion time.In slow-diffusion area,both magnetization attenuation and self-diffusion coefficients are independent of surface relaxivity within short diffusion time.These results agree well with theoretical analysis.Surfaceto-volume ratio and pore size can be determined.

The valence band offsets ΔE_v(x) as a function of the alloy compositon x of two typical lattice matched ternary alloy heterojunctions (AlP)_x(Si₂)_1-x/GaP and (GaP)_x(Si₂)_1-x/GaP are studied by using the average bond energy theory in conjunction with the cluster expansion method.It is shown that the variations of ΔE_v(x) at (AlP)_x(Si₂)_1-x/GaP and (GaP)_x(Si₂)_1-x/GaP are nonlinear and non monotonous.The calculated results of ΔE_v are in very good agreement with the data previously reported.