Abstract: A tracer particle spreading device for a boundary layer flow visualization experiment based on a flat plate includes a tracer particle generator, a smoke storage box, and a wall-surface particle distribution box. Fume and oil are pressurized by a micro pump and flows into a heating pipe to be heated and vaporized, and then is ejected from a nozzle to form tracer particles. The tracer particles enter the smoke storage box via a smoke guiding tube. An axial flow fan is mounted on a wall surface of the smoke storage box. The tracer particles enter a cavity of the wall-surface particle distribution box via the smoke guiding tube, and the tracer particles are rectified by a rectifying plate and ejected from a spreading slit. An outlet of the spreading slit is at an angle of 15° with respect to an experiment flat plate.

Abstract: A multimedia playback method includes: playing first multimedia data, switching from playing the first multimedia data to playing a multimedia frame corresponding to a target starting point of second multimedia data, based on a media switching operation, the second multimedia data including multimedia frames corresponding to a plurality of time points, the plurality of time points including pre-configured P candidate starting points, and the target starting point belonging to the P candidate starting points, and switching, during the playing of the second multimedia data, from playing a first multimedia frame in the second multimedia data to playing a new multimedia frame corresponding to a new starting point, based on a target triggering operation, the first multimedia frame being a multimedia frame played at a moment at which the target triggering operation is performed, and the new starting point being a candidate starting point other than the target starting point. .

Abstract: A read-write method includes: sequentially writing, in a first direction, a code word obtained by information-bit encoding into a target memory cell in each layer of memory cell array in the three-dimensional memory; randomly reading the target memory cell in each layer of memory cell array, or sequentially reading the target memory cell in each layer of memory cell array in a second direction; and determining an LLR value of a current target memory cell according to a storage time corresponding to the current target memory cell when reading, a threshold voltage partition corresponding to the current target memory cell when reading, a comprehensive distribution state corresponding to the current target memory cell when reading, and a pre-established LLR table, so as to perform a soft decoding operation on the code word in the current target memory cell based on the LLR value of the current target memory cell.

Abstract: The method includes: reading a memory cell having a encoded information bit, so as to obtain an LLR value of a current memory cell with reference to a pre-established LLR table according to a storage time, a threshold voltage partition and a comprehensive distribution corresponding to the current memory cell during reading; and performing a soft decoding operation on a codeword in the memory cell having the encoded information bit according to the read LLR value of the current memory cell, wherein the comprehensive distribution of the current memory cell is determined according to an influence of a memory cell adjacent to the current memory cell on a distribution of the current memory cell; an input of the pre-established LLR table comprises a storage time, a threshold voltage partition and a comprehensive distribution, and an output of the pre-established LLR table comprises an LLR value.

Abstract: The disclosure provides a micro-groove drag reduction flexible film and a preparation method thereof. The micro-groove film has a triangular groove structure on the upper surface along the direction of an air flow, and an adhesive layer on the lower surface for quick adhesion to an aircraft surface. After the surface of the aircraft is covered with a micro-groove film, it could limit the spanwise movement of the bottom air at the boundary layer of the aircraft surface, improve the flow field characteristics of the aircraft near the wall, and effectively reduce the frictional resistance of the wall. The micro-groove flexible film is prepared by a roller hot pressing method. The triangular groove structure is processed on the surface of the mold roller of the double roller hot press. After pretreatment of the thermoplastic polyurethane (TPU) polymer film, a micro-groove structure is hot-pressed on the surface of the TPU film.

Abstract: A tracer particle spreading device for a boundary layer flow visualization experiment based on a flat plate includes a tracer particle generator, a smoke storage box, and a wall-surface particle distribution box. Fume and oil are pressurized by a micro pump and flows into a heating pipe to be heated and vaporized, and then is ejected from a nozzle to form tracer particles. The tracer particles enter the smoke storage box via a smoke guiding tube. An axial flow fan is mounted on a wall surface of the smoke storage box. The tracer particles enter a cavity of the wall-surface particle distribution box via the smoke guiding tube, and the tracer particles are rectified by a rectifying plate and ejected from a spreading slit. An outlet of the spreading slit is at an angle of 15° with respect to an experiment flat plate.