We look for similarity transformations which yield mappings between different
one-dimensional reaction-diffusion processes. In this way results obtained for
special systems can be generalized to equivalent reaction-diffusion models. The
coagulation (A + A -> A) or the annihilation (A + A -> 0) models can be mapped
onto systems in which both processes are allowed. With the help of the
coagulation-decoagulation model results for some death-decoagulation and
annihilation-creation systems are given. We also find a reaction-diffusion
system which is equivalent to the two species annihilation model (A + B ->0).
Besides we present numerical results of Monte Carlo simulations. An accurate
description of the effects of the reaction rates on the concentration in
one-species diffusion-annihilation model is made. The asymptotic behavior of
the concentration in the two species annihilation system (A + B -> 0) with
symmetric initial conditions is studied.Comment: 20 pages latex, uuencoded figures at the en