Abstract: A brazing joint, a brazing method, and a device for promoting solder rheology and gas overflow are provided. The brazing joint includes a first base metal, a second base metal, and a brazing seam located therebetween. The brazing seam is formed by filling a solder in a gap formed by welding surfaces of the first and the second base metal and melting it to connect the first and the second base metal. The brazing seam is a concave-shaped brazing seam. The gap defines a first distance and a second distance, the first distance is located at an edge of the gap, the second distance is located at the edge or an inside of the gap, the first distance is greater than the second distance, and a curved surface is formed between the location of the first distance and the location of the second distance for transition.

Abstract: Image encryption and decryption methods based on biological information. The encryption method includes: obtaining the biological information; using the chaotic mapping method to preprocess the biological information to construct the first chaotic biological phase plate and the second chaotic biological phase plate; obtaining the original image to be encrypted and use the first chaotic biological phase plate and the second chaotic biological phase plate to determine the reconstructed optical encrypted image based on the discrete cosine transform method, and Fresnel transform method; and inputting reference light that interferes with the encrypted image of the reproduction light to determine the encrypted image. The invention can reduce the information amount of the key, improve the efficiency of storage and transmission, and improve security.

Abstract: Image encryption and decryption methods based on biological information. The encryption method includes: obtaining the biological information; using the chaotic mapping method to preprocess the biological information to construct the first chaotic biological phase plate and the second chaotic biological phase plate; obtaining the original image to be encrypted and use the first chaotic biological phase plate and the second chaotic biological phase plate to determine the reconstructed optical encrypted image based on the discrete cosine transform method, and Fresnel transform method; and inputting reference light that interferes with the encrypted image of the reproduction light to determine the encrypted image. The invention can reduce the information amount of the key, improve the efficiency of storage and transmission, and improve security.