Abstract: A Head up display system includes a projection light source, laminated glass, and a transparent nano film. The transparent nano film includes at least one laminated structure consisting of a high refractive-index layer and a low refractive-index layer, where the high refractive-index layer and the low refractive-index layer is deposited sequentially outwards from the surface of the inner glass pane. The projection light source is configured to generate P-polarized light. A ratio of near-red light reflectivity R1 at wavelengths ranging from 580 nm to 680 nm of the laminated glass with the transparent nano film to near-blue light reflectivity R2 at wavelengths ranging from 420 nm to 470 nm of the laminated glass with the transparent nano film is R1/R2=1.0˜2.0.

Abstract: Disclosed in embodiments of the present invention are a control method and device for an alternating-current and direct-current conversion circuit, and a computer storage medium. The alternating-current and direct-current conversion circuit comprises a first commutation unit, a second commutation unit, and a coupling unit. By obtaining voltage information and current information of the alternating-current and direct-current conversion circuit, a controllable device of the first commutation unit can be controlled to be turned on in delay or turned off in advance; and the second commutation unit is controlled to work in a controllable rectification state or a controllable inversion state or an uncontrollable rectification state.

Abstract: Disclosed in embodiments of the present invention are a control method and device for an alternating-current and direct-current conversion circuit, and a computer storage medium. The alternating-current and direct-current conversion circuit comprises a first commutation unit, a second commutation unit, and a coupling unit. By obtaining voltage information and current information of the alternating-current and direct-current conversion circuit, a controllable device of the first commutation unit can be controlled to be turned on in delay or turned off in advance; and the second commutation unit is controlled to work in a controllable rectification state or a controllable inversion state or an uncontrollable rectification state.

Abstract: A geothermal power system includes a steam turbine and a closed loop working fluid system having a preheater, a vaporizer, a superheater, an expander, a condenser, and a pump and a working fluid disposed to pass sequentially through the preheater, vaporizer, superheater, expander, condenser, and pump. Geothermal fluid is separated into a steam stream and a brine stream. The steam is expanded across the steam turbine to generate power, and thereafter exhaust from the steam turbine passes through the vaporizer to vaporize the working fluid. Geothermal brine is first used to heat vaporized working fluid in the superheater and is then used to preheat liquid working fluid in the preheater.