Left: 2D density (top) and temperature (bottom) distributions of model Σ_peak = 2 × 10⁻⁴ g cm⁻², α = 0.01, σ = 20 au and Σ_floor/Σpeak = 0.001. Middle: the density and temperature distributions with only small grains included. Right: with only big grains included. The white curves in top panels are the one scale-height contours of small (upper one) and big (lower one) grains.