  We have performed an angle-resolved photoemission study of the nodal
quasi-particle spectra of the high-Tc cuprate tri-layer Bi2Sr2Ca2Cu3O10+d (Tc~
110 K). The spectral weight Z of the nodal quasi-particle increases with
decreasing temperature across the Tc. Such a temperature dependence is
qualitatively similar to that of the coherence peak intensity in the anti nodal
region of various high-Tc cuprates although the nodal spectral weight remains
finite and large above Tc. We attribute this observation to the reduction of
electron correlation strength in going from the normal metallic state to the
superconducting state, a characteristic behavior of a superconductor with
strong electron correlation.
