Optoelectronic characteristics of single ZnAlO nanotetrapod

The ZnAlO nanotetrapods were prepared by a simple thermal evaporation method. The typical characteristics of I-V curves for one of our devices illustrated that both the green light and the UV light could induce the increasing of conductance, but the conductance under the UV light is much larger than that under the illumination of green light. With the increasing of temperature, the conductance of the sample is also increased. Furthermore, the change of current versus time as the UV light is switched on and off shows the sample has good switch characteristics. These findings illustrate the sample may be used in room temperature light sensors.     

Effect of attack angle change on hydrodynamic character of supercavitating bodies

A series of experiments has been done in a moderate-velocity cavitation tunnel to investigate the effects of attack angle change on hydrodynamic characters of supercavitation. Hydrodynamic characters of the aft section at various attack angles were compared. The investigation shows that hydrodynamic forces of the aft section are dependent of supercavity shapes at different attack angles,and the magnitude of hydrodynamic forces of the aft section varies with the change of attack angle. When the aft section is in the fully wetted case,the drag coefficient changes little. Lift and moment coefficients both increase with the increased attack angle,and the increase magnitude is not large. When the aft body planing is on the cavity boundary,the drag coefficient of nonzero attack angle is larger than that of zero attack angle,and the maximal lift and moment coefficients both vary obviously with the increased attack angle. In the case that the body is fully enveloped by cavity,the drag coefficient,lift coefficient and moment coefficient are nearly constant with the change of attack angles.