  We have measured the photoemission spectra of Nd$_{1-x}$Sm$_{x}$NiO$_{3}$,
where the metal-insulator transition and the N\'{e}el ordering occur at the
same temperature for $x \lesssim 0.4$ and the metal-insulator transition
temperature ($T_{MI}$) is higher than the N\'{e}el temperature for $x \gtrsim
0.4$. For $x \le 0.4$, the spectral intensity at the Fermi level is high in the
metallic phase above $T_{MI}$ and gradually decreases with cooling in the
insulating phase below $T_{MI}$ while for $x > 0.4$ it shows a pseudogap-like
behavior above $T_{MI}$ and further diminishes below $T_{MI}$. The results
clearly establish that there is a sharp change in the nature of the electronic
correlations in the middle ($x \sim 0.4$) of the metallic phase of the
$R$NiO$_3$ system.
