| In this paper,we use the variational methods to study the following Schr(?)dinger-Poisson system:where 0≠λR,f:R3 × R→R,the functions K(x)and M(u)= ∫0u m(s)ds are nonnegative and nonzero,and for any given u ∈ D1,2(R3),the function K(x)M(u)∈L6/5(R3).Firstly,we consider one kind of Schr(?)dinger-Poisson system with two critical exponents,where λ∈R,2 ≤ p ≤ 6,|u|4u and φ|u|3u are local and nonlocal Sobolev critical terms respectively.By combining the variational methods,Mountain Pass theo-rem,strong maximun principle and Pohoz(?)ev identity,we prove the existence and nonexistence results for nontrivial solutions of system(SP1).Secondly,we study the following Schr(?)dinger-Poisson system which involves two critical exponents but no perturbation terms,where μ∈R.By using the variational methods,minimization techniques,Lagrange multiplier rule and Pohoz(?)ev identity,we prove the existence and nonexistence re-sults for nontrivial solutions of system(P1).At last,we study the following modified critical Schr(?)dinger-Poisson system:where V,K,g are asymptotically periodic functions of x and g ∈C(R3 × R,R).By combining the variational methods,Mountain Pass theorem,the Concentration-compactness principle and the strong maximum principle,we prove the existence of a positive ground state solution of system(SP2). |