This paper concerns the sharp threshold of blowup and global existence of the solution as well as the strong instability of standing wave eu(x) to the system iφt +Δφ+ a|φ|p−1φ+ bE1(|φ|)φ = 0 (DS) in R , where a > 0, b > 0, 1 ≤ p < N+2 (N−2)+ , N ∈ {2, 3} and u is a ground state. First, by constructing a type of cross-constrained variational problem and establishing so-called cross-invariant man...