Λ u= f (u),\quad t> 0,\quad x ∈ Ω ⊂ R^ N, where− Λ denotes the Laplacian with zero
Dirichlet boundary condition in L 2 (Ω). For a dissipative nonlinearity f satisfying a suitable
growth restrictions these equations define on the phase space H^ 1_0 (Ω) * L^ 2 (Ω)
semigroups {T_ η (t): t\geqslant 0\} which have global attractors A η, η\geqslant 0. We show
that the family {A_ η\} _ η\geqslant 0, behaves upper and lower semicontinuously as the …