Abstract With the mass application of drones in daily work, more attention has been paid to noise problem. The generation mechanism low Reynolds number propellers is studied this paper. It found that there are laminar separation bubbles on suction surface, causing an increase broadband noise. Leading edge boundary layer trips added remove bubbles. Finally, experimental measurements indicate iso...

The 3-D coordination polymer with the basic formula Cd2(TCNQ)3.5(H2O)2 is the first instance of the coexistence of the bridging modes μ2, μ3 and μ4 for TCNQ in one network. Single crystal measurements revealed the compound to be a good semiconductor with a room temperature conductivity of 5.8 × 10(-3) S cm(-1).