Abstract: The present application relates to an LED epitaxial structure and the preparation method and application thereof. The LED epitaxial structure comprises a first multiple-quantum-well light-emitting layer and a second multiple-quantum-well light-emitting layer. The first multiple-quantum-well light-emitting layer comprises a first shoes layer, a first well layer, a first cap layer, and a first Barrier layer epitaxially grown from bottom to top in sequence. The second multiple-quantum-well light-emitting layer comprises a second shoes layer, a second well layer, a second cap layer, and a second Barrier layer epitaxially grown from bottom to top in sequence. The technical solutions disclosed in the present application can solve the problem that the 365 nm to 375 nm wave band LED would emit yellow light.

Abstract: Disclosed are a sleeve grouting device and method for prefabricated building, relating to the technical field of engineering construction. The grouting device includes a sleeve, a driver and an oscilloscope, sleeve openings at two ends of the sleeve each are configured to be penetrated by connection rebars of each of two different prefabricated components, a piezoelectric ceramic is provided horizontally at each of the sleeve openings at two ends of the sleeve, a corresponding one of the piezoelectric ceramics is electrically connected to the driver and another corresponding one of the piezoelectric ceramics is electrically connected to the oscilloscope; a bottom end of the sleeve is connected to an inlet pipe to be communicated with a g grout injection equipment, and a top end of the sleeve is connected to an outlet pipe.

Abstract: Disclosed are a sleeve grouting device and method for prefabricated building, relating to the technical field of engineering construction. The grouting device includes a sleeve, a driver and an oscilloscope, sleeve openings at two ends of the sleeve each are configured to be penetrated by connection rebars of each of two different prefabricated components, a piezoelectric ceramic is provided horizontally at each of the sleeve openings at two ends of the sleeve, a corresponding one of the piezoelectric ceramics is electrically connected to the driver and another corresponding one of the piezoelectric ceramics is electrically connected to the oscilloscope; a bottom end of the sleeve is connected to an inlet pipe to be communicated with a g grout injection equipment, and a top end of the sleeve is connected to an outlet pipe.