Spectral Properties of MHD Turbulence in 2.5-Dimensional Compressible Plasmas

<正> Spectral properties of magnetohydrodynamic(MHD)turbulence with a strong back-ground mean magnetic field in 2.5-dimensional compressible plasmas are studied by high-resolutionnumerical simulations.The spatial properties of MHD turbulences and the energy transfer pro-cess in the k-space are analyzed through angle-averaged energy spectrum.It is found that in theinertial phase,the energy spectrum index of compressible MHD turbulences during the decayingphase is evolved with time.The index varies in a quite wide regime from Kolmogorov's 5/3 toIK's 3/2 during the late simulation period.The energy spectrum index in the later nonlinear stageis also dependent on the chosen initial conditions.The spectral index increases with the increaseof the initial magnetic fluctuation while the index decreases with the increase of the initial flowperturbation.