Abstract: The present disclosure relates to the technical field of solid waste recycling and fabricated buildings, and provides a solid waste large-mixing-amount concrete prefabricated laminated slab and a preparation method thereof. The solid waste large-mixing-amount concrete prefabricated laminated slab provided by the present disclosure comprises a prefabricated layer and a laminated layer. Transverse grooves and longitudinal grooves are formed in the surface of the prefabricated layer. During application, the grooves can be used for erecting pipelines, the contact area of the prefabricated layer and the laminated layer can also be increased, the combined effect of new concrete and old concrete is improved, the integrity of a floor slab is enhanced, and the effect of improving the overall stress capacity of the floor slab is achieved.

Abstract: Examples of the present disclosure provide a method and an apparatus for processing a brightness of a display screen, and an electronic device. The method includes: obtaining a subject object of an image based on image information of the image; obtaining a first contrast of the subject object and a first gray level of the image; and adjusting a brightness of a display screen displaying the image based on the first contrast and the first gray level.

Abstract: Examples of the present disclosure provide a method and an apparatus for processing a brightness of a display screen, and an electronic device. The method includes: obtaining a subject object of an image based on image information of the image; obtaining a first contrast of the subject object and a first gray level of the image; and adjusting a brightness of a display screen displaying the image based on the first contrast and the first gray level.

Abstract: The present disclosure relates to the technical field of solid waste recycling and fabricated buildings, and provides a solid waste large-mixing-amount concrete prefabricated laminated slab and a preparation method thereof. The solid waste large-mixing-amount concrete prefabricated laminated slab provided by the present disclosure comprises a prefabricated layer and a laminated layer. Transverse grooves and longitudinal grooves are formed in the surface of the prefabricated layer. During application, the grooves can be used for erecting pipelines, the contact area of the prefabricated layer and the laminated layer can also be increased, the combined effect of new concrete and old concrete is improved, the integrity of a floor slab is enhanced, and the effect of improving the overall stress capacity of the floor slab is achieved.

Abstract: Multi-solid waste activated concretes with high-silicon iron ore tailings and preparation methods thereof are disclosed. In at least some embodiments, the concrete is prepared from raw materials including 360-380 kg/m3 of a cement, 30-40 kg/m3 of fly ash, 30-40 kg/m3 of a modified ultrafine sand of high-silicon iron ore tailings, 930-950 kg/m3 of a waste stone of tailings, 870-930 kg/m3 of a fine sand of tailings, 160-170 kg/m3 of water, and 4-8 kg/m3 of an additive.

Abstract: A method for a direct current (DC) islanding detection based on positive feedback of a bus voltage at a specific frequency, essentially including three steps: extraction of a specific frequency component of the bus voltage, injection of a disturbance component of the specific frequency, and determination of DC islanding. The extraction of the specific frequency component of the bus voltage and the injection of the disturbance component of the specific frequency constitute a positive feedback mechanism in a power management unit control loop. In a grid-connected mode of a DC grid, the positive feedback mechanism fails due to a control action of a voltage management unit on a bus, and the bus voltage remains stable. In an islanding mode of the DC grid, under an action of the positive feedback mechanism, the power management unit allows the bus voltage to generate a self-excited oscillation at the specific frequency.