We present the centrality dependence of proton and deuteron rapidity distributions inRu+Rucollisions at400A MeV.The ratio of baryon rapidity distributions in isospin asymmetric collision systems shows incomplete mixing and transparency of the projectile and target nucleons at this beam energy. In addition, we also present the results of thermal model calculations including both a modification of the &Dgr;(1232) spectral function and the Coulomb interaction. The model calculations are compared with the published pion spectra for centralAu+Aucollisions at1A GeV.©2001 American Institute of Physics.