Abstract: A method produces tantalum powder. The method includes: (1) uniformly mixing a tantalum powder raw material, metal magnesium and at least one alkali metal and/or alkaline earth metal halide, loading the mixture into a container, and putting the container in a furnace; (2) raising the temperature of the furnace to 600-1200° C. in the presence of inert gas, and soaking; (3) at the end of soaking, lowering the temperature of the furnace to 600-800° C., vacuumizing the interior of the furnace to 10 Pa or less, soaking under the negative pressure so that the excessive metal is separated; (4) thereafter, raising the temperature of the furnace to 750-1200° C. in the presence of inert gas, and soaking so that the tantalum powder is sintered in the molten salt after oxygen reduction; (5) then cooling to room temperature and passivating to obtain a mixed material containing halide and tantalum powder; and (6) separating the tantalum powder from the resulting mixture.

Abstract: A low-carbon, high-purity tantalum pentoxide powder has a carbon content of no greater than 15 ppm. A preparation method for the powder includes: (1) adding a fluotantalic acid (H2TaF7) solution into a reaction kettle, controlling the temperature of the reaction kettle at 30-60° C., adding a precipitator until the pH of the reaction solution is 8-10, then stopping introducing ammonia, and aging to obtain a tantalum hydroxide slurry; (2) filtering and washing the slurry obtained in step (1), and then carrying out solid-liquid separation to obtain a tantalum hydroxide filter cake; (3) drying the filter cake obtained in step (2) to obtain white tantalum hydroxide powder; (4) calcining the tantalum hydroxide powder obtained in step (3), crushing and screening the calcined sample to obtain tantalum pentoxide powder; and (5) subjecting the tantalum pentoxide powder obtained in step (4) to heat treatment at a temperature of 1000-1500° C. to obtain the powder.

Abstract: The present disclosure relates to a nitrogen-doped porous carbon material and a preparation method and use thereof. In the present disclosure, the preparation method of a nitrogen-doped porous carbon material includes the following steps: conducting carbonization on a biomass material to obtain a carbon source; and mixing the carbon source with a potassium 4-aminobenzoate aqueous solution, and drying and conducting calcination in a protective atmosphere sequentially to obtain the nitrogen-doped porous carbon material. In the preparation method, the potassium 4-aminobenzoate is used as a nitrogen source as well as an activator for preparing the nitrogen-doped porous carbon material. Nitrogen doping is simultaneously completed during the activation, and the nitrogen-doped porous carbon material can be prepared through one-step calcination.

Abstract: A system and method for performing electrochemically-cycled oxidation on landfill leachate are provided for the removal of organic materials in landfill leachate which have an ultraviolet absorbance at 254 nm (UVA254), thus pre-treating the landfill leachate for co-treatment through dilution with municipal sewage. Electrochemical oxidation is performed on the landfill leachate in a first reactor chamber to produce hypochlorite (OCl?), followed by delayed application of ultraviolet radiation to produce hydroxyl radicals (OH•) and reactive chlorine species to break bonds in the organic materials. A portion of this partially-treated landfill leachate is then fed to a second reactor chamber for subsequent dichlorination through ultraviolet photolysis. An equivalent volume of fresh landfill leachate is fed into the first reactor chamber to begin the cycle again, allowing for continuous treatment of a source of landfill leachate.

Abstract: The present document provides a scene recognition method and device based on ambient sound and a mobile terminal. The device includes: a sound collection module, a preprocessing module, a feature extraction module, a scene recognition module and a database. The method includes: collecting a sound signal; processing the sound signal into a frequency domain signal; extracting sound feature information from the frequency domain signal; inputting the sound feature information under a preset model, matching a model output result with weight values of sound sample models of scenes, and determining a scene corresponding to the sound feature information. The present document implements locating based on background sound information as the feature of the scene, so that the mobile terminal quickly and correctly recognizes the current scene under the maintaining low-consumption state.

Abstract: The present document provides a scene recognition method and device based on ambient sound and a mobile terminal. The device includes: a sound collection module, a preprocessing module, a feature extraction module, a scene recognition module and a database. The method includes: collecting a sound signal; processing the sound signal into a frequency domain signal; extracting sound feature information from the frequency domain signal; inputting the sound feature information under a preset model, matching a model output result with weight values of sound sample models of scenes, and determining a scene corresponding to the sound feature information. The present document implements locating based on background sound information as the feature of the scene, so that the mobile terminal quickly and correctly recognizes the current scene under the maintaining low-consumption state.

Abstract: Aspects of the invention relate to techniques for modeling content-addressable memory for emulation. An emulation device according to various embodiments of the invention comprises one or more memory modeling blocks reconfigurable to emulate a content-addressable memory or a random-access memory. The emulation device may be processor-based or FPGA-based. Each of the one or more memory modeling blocks comprises memory circuitry and a dedicated comparison unit configured to compare a search word or a portion of a search word received by the each of the one or more memory modeling blocks with data stored in the memory circuitry. The comparison unit may comprise a comparator and a register coupled to the comparator and configured to store matching data. The matching data may be unencoded matching data. A plurality of the memory modeling blocks may be programmable to emulate a single content-addressable memory.