Abstract
We study the pre-Lie algebra of specified Feynman graphs (V) over tildeT and we define a pre-Lie structure on its doubling space (F) over tilde (T). We prove that (F) over tilde (T) is pre-Lie module on (V) over tilde (T) and we find some relations between the two pre-Lie structures. Also, we study the enveloping algebras of two pre-Lie algebras denoted respectively by ((D) over tilde (T),(star,Phi)') and ((H) over tilde (T,star,Psi)') and we prove that ((D) over tilde (T),(star,Phi)') is a module-bialgebra on ((H) over tilde (T,star,Psi)').