  We study numerically time evolution of a system which consists of two
attractors connected by Fermi-Pasta-Ulam (FPU) chain. It is found that after
sufficiently long time there exits self-consistent large scale structure in the
system. The wavelet transform is used to separate the modes in different
scales. We found that the nonlinear long wavelength mode propagating along the
chain assists the energy transport. Further, all points in the system are found
to be correlated. Our results explain satisfactorily why the chaotic behaviour
is not enough to ensure the Fourier heat law and the thermal conductivity
diverges as it is found recently by Lepri et al (PRL 78, 1897(1997).).
