Growth and passivation of aluminum etch tunnels at on-off controlling DC

In order to control the length of tunnels within Al foil etched in HCl-H₂SO₄ solutions, the influence of on-off control of the DC on growth and passivation of tunnels has been investigated. From SEM of oxide replicas of tunnels, it was found that, in a given etchant solution at a special temperature, the longest tunnel length depended only on the turn-on interval of DC, and the number of pits was determined by the total electricity of the DC. The corresponding mechanism is that the potential of Al foil changed rapidly at the point of the switch of DC by the result according to the anodic polarization curve and potential-time (E-t) response curves. The moment the DC was switched on, the potential increased immediately over pitting potential, leading to nucleation of pits at the surface and growth of tunnels at special lengths. When the DC was switched off, the potential rapidly decreased to a passive state, leading to the cessation of nucleation and the death of tunnels. Therefore, the longest tunnel length can be controlled and a non-piercing layer can be obtained. Furthermore, consequent etching of Al foil by the on-off control of the DC is beneficial for maintaining a good mechanical strength.     

客车电动外摆门驱动控制系统

本文介绍了新开发成功的客车电动外摆门驱动控制系统 .该驱动控制系统满足了豪华客车对外摆自动门的要求 ,特别适用于无压缩气源的中型豪华旅游客车     

Growth and characterization of CuInSe2 thin films prepared by successive ionic layer adsorption and reaction method with different deposition temperatures

CuInSe₂ films were prepared at different deposition temperatures (T_D) by successive ionic layer adsorption and reaction method with chelating solutions. Influence of T_D on film growth, morphology, crystal structure, and band gap energy was investigated. Results showed that elevation of T_D mainly enhanced reaction kinetics and ionic diffusion velocity, resulting in fast growth rate of CuInSe₂ films, and maximum 20-30 nm/cycle depended upon T_D were acquired. Films with 60 dip-cycles could grow from 180 nm to 1000 nm by elevating T_D from 30 °C to 90 °C. Surface roughness of CuInSe₂ films was closely related to dip-cycle times and T_D. Accelerated growth rate by T_D could reduce the dip-cycle times for a required film thickness, which improved quality of film morphology.