  We present molecular dynamics simulations on the segregation of binary
mixtures in a high-velocity rotating drum. Depending on the ratio of particle's
radius and density, the ring-like spin segregation patterns in radial direction
show similarities to the Brazil-nut effect and its reverse form. The smaller
and heavier particles are easier to accumulate towards the drum wall and the
bigger and lighter ones towards the drum center. Furthermore, we quantify the
effects of particle's radius and density on the segregation states and plot the
phase diagram of segregation in the ${\rho_b}/{\rho_s}$ - ${r_b}/{r_s}$ space.
The observed phenomena can also be well explained by the combined actions,
i.e., the percolation effect and the buoyancy effect.
