摘要：Active fluids consist of self-propelled agents, which inject energy into the system at microscopic scales. The hydrodynamic interactions between these agents play important roles in material properties of active fluids. In this talk, I employ bacterial suspensions as model systems to study two hydrodynamics-dominated phenomena in active fluids and try to answer the following questions. (1) Whether universal scalings exist in active turbulence, and how the dimensionality changes the behaviors of active turbulence? (2) How the hydrodynamic interactions affect the effective interactions between two passive walls in active fluids?