▎ 摘　　要

We study Dirac fermions in gapped graphene that are subjected to a magnetic field and a harmonically oscillating in time potential barrier. The tunneling modes inside the gap and the associated Goos-Hanchen (GH) shifts are analytically and numerically investigated. We show that the GH shifts in transmission for the central band and the first two sidebands change sign at the Dirac points epsilon + l (h) over bar(omega) over tilde (l = 0, +/- 1). We also find that the GH shifts can be either negative or positive and becomes zero at transmission resonances.