Abstract: Disclosed is a ruthenium-based catalyst for ammonia synthesis, preparation method and use thereof. The ruthenium-based catalyst comprises Ru—Ba-A core-shell structure which comprises a ruthenium nanoparticle as a core covered with a first shell and a second shell sequentially, wherein the first shell consists of a barium nanoparticle, and the second shell consists of a metal oxide. The Ru—Ba-A core-shell structure can effectively preventing agglomerations of ruthenium nanoparticles during the use of the catalyst and avoiding direct contact between the ruthenium nanoparticles and the metal oxides. In addition, barium nanoparticles have a promoting effect as an electronic promoter, which can effectively improve the stability and catalytic activity of ruthenium-based catalyst for ammonia synthesis, especially in the system for synthesizing ammonia from a coal gas.

Abstract: This application discloses a Bluetooth reconnection method, and relates to the field of short-range wireless communications technologies. The method includes: When a charging case is closed, a first earbud breaks a Bluetooth connection, where the first earbud stores a Bluetooth address of a terminal and a Bluetooth address of a second earbud. When the charging case is opened, the charging case accommodates only the first earbud, and a first preset condition is met, the first earbud sends a first paging request to the second earbud based on the Bluetooth address of the second earbud. The first preset condition is that the Bluetooth connection includes a Bluetooth connection between the first earbud and the second earbud. In this way, reconnection duration of the first earbud when the charging case is opened can be reduced.

Abstract: A wireless short-range audio sharing method implemented by an audio device, where the wireless short-range audio sharing method includes detecting a first operation of a user, enabling, in response to the first operation, a BLUETOOTH Low Energy (BLE) advertising function, detecting a second operation of the user, selecting, in response to the second operation, an audio file, converting the audio file into an audio data packet, performing BLE advertising on the audio data packet, and performing periodic advertising corresponding to the BLE advertising.

Abstract: An ammonia decomposition apparatus comprises a casing, a heating zone, a heat exchange zone, a reaction section and a heat exchange coil. The heat exchange coil is spirally wound on an outer wall of the reaction section to efficiently heat ammonia gas. The reaction section has a first reaction zone and a second reaction zone communicated successively, the ammonia gas decomposed into a nitrogen-hydrogen mixture after entering the first reaction zone, with the second reaction zone decomposing for the second time the residual ammonia gas in the nitrogen-hydrogen mixture produced in the first reaction zone, so that the ammonia gas is decomposed more thoroughly. The conversion rate of ammonia gas can reach 99.9% or more, and the residual amount of ammonia gas in the nitrogen-hydrogen mixture can be less than 1000 ppm.

Abstract: Disclosed is a ruthenium-based catalyst for ammonia synthesis, preparation method and use thereof. The ruthenium-based catalyst comprises Ru—Ba-A core-shell structure which comprises a ruthenium nanoparticle as a core covered with a first shell and a second shell sequentially, wherein the first shell consists of a barium nanoparticle, and the second shell consists of a metal oxide. The Ru—Ba-A core-shell structure can effectively preventing agglomerations of ruthenium nanoparticles during the use of the catalyst and avoiding direct contact between the ruthenium nanoparticles and the metal oxides. In addition, barium nanoparticles have a promoting effect as an electronic promoter, which can effectively improve the stability and catalytic activity of ruthenium-based catalyst for ammonia synthesis, especially in the system for synthesizing ammonia from a coal gas.

Abstract: An ammonia decomposition apparatus comprises a casing, a heating zone, a heat exchange zone, a reaction section and a heat exchange coil. The heat exchange coil is spirally wound on an outer wall of the reaction section to efficiently heat ammonia gas. The reaction section has a first reaction zone and a second reaction zone communicated successively, the ammonia gas decomposed into a nitrogen-hydrogen mixture after entering the first reaction zone, with the second reaction zone decomposing for the second time the residual ammonia gas in the nitrogen-hydrogen mixture produced in the first reaction zone, so that the ammonia gas is decomposed more thoroughly. The conversion rate of ammonia gas can reach 99.9% or more, and the residual amount of ammonia gas in the nitrogen-hydrogen mixture can be less than 1000 ppm.