The purpose of this paper is to give a characterization of the structure of
non-autonomous attractors of the problem ut=uxx+λu−β(t)u3 when the parameter λ>0 varies. Also, we answer a
question proposed in [11], concerning the complete description of the structure
of the pullback attractor of the problem when 1<λ<4 and, more
generally, for λ=N2, 2≤N∈N. We construct
global bounded solutions , "non-autonomous equilibria", connections between the
trivial solution these "non-autonomous equilibria" and characterize the
α-limit and ω-limit set of global bounded solutions. As a
consequence, we show that the global attractor of the associated skew-product
flow has a gradient structure. The structure of the related pullback an uniform
attractors are derived from that.Comment: 32 pages, 04 figure