Abstract: The present disclosure provides a reservoir desilting device having a funnel with a bivariate normal surface, which belongs to the technical field of water conservancy projects. The device includes a sediment inlet funnel and a sediment transport pipeline, where the sediment inlet funnel is located in a sediment accumulation area in a reservoir, the sediment transport pipeline is laid on a river bed of the reservoir, a bottom of the sediment inlet funnel is connected to one end of the sediment transport pipeline, and the other end of the sediment transport pipeline penetrates out of a bottom of a dam; and the sediment transport funnel has a shape of a bivariate normal surface, the sediment transport pipeline has a shape of an inverse hyperbolic geodesic curve, and the sediment transport pipeline is provided with a valve.

Abstract: This invention is related to the process and apparatus for applying stressed skin sheet coverings to large passenger vehicles. The apparatus for the process, provided by this invention includes a single phase transformer, conductors, electric contactors and a guiding apparatus. The present invention uses a specialized transformer, capable of producing a strong electric current of low voltage as an energy source, utilizing the steel skin sheet as a resistor element in the output circuit, welding the steel sheet onto the frame while the steel sheet is heated by the electric current passing through the sheet, thereby elongating the sheet at a set value due to the rise in temperature, cutting off the electricity and welding the upper and lower sides quickly onto the frame, thus finishing the process of skin covering and resulting in residual stresses within the steel skin sheet.