  In this paper, a generalized (3 + 1)-dimensional variable-coefficient
nonlinear-wave equation is studied in liquid with gas bubbles. Based on the
Hirota's bilinear form and symbolic computation, lump and interaction solutions
between lump and solitary wave are obtained. Their interaction phenomena is
shown in some 3d graphs and contour plots, which include a periodic-shape lump
solution, a parabolic-shape lump solution, a cubic-shape lump
solution,interaction solutions between lump and one solitary wave, and between
lump and two solitary waves. The spatial structures called the bright lump wave
and the bright-dark lump wave are discussed. Interaction behaviors of two
bright-dark lump waves and a periodic-shape bright lump wave are also
presented.
