Abstract: The present disclosure provides a method for photo-curing 4D printing of a multi-layer structure with an adjustable shape recovery speed, and a multi-layer structure printed thereby. The multi-layer structure printed by the method for photo-curing 4D printing of the multi-layer structure with the adjustable shape recovery speed includes a plurality of deformation units sequentially connected in series, and each of the plurality of the deformation units includes two slow layers, a fast layer, and a transition layer; and the fast layer is arranged between the two slow layers, and the transition layer is arranged between at least one of the two slow layers and the fast layer. In the present disclosure, a low cross-linking layer is doped with a nanocarbon light-absorbing material to solve the problem that the low cross-linking layer is prone to over-curing when a high cross-linking layer is printed on the low cross-linking layer.

Abstract: Disclosed are a material analysis method based on the crystal structure database, a system, a computer-readable storage medium and an application. The material analysis method includes comparing experimental pattern information obtained from examination of a to-be-tested sample with theoretical pattern information calculated from material structure data in the crystal structure database, and obtaining crystallographic information and phase composition of the to-be-tested sample through intelligent analysis. The crystallographic information include space group, unit cell parameter, and specific coordinates of atoms in unit cell. The crystal structure database has material structure data obtained by experimental measurement and/or theoretical prediction, including chemical formula, space group, unit cell parameter and specific coordinates of atoms in unit cell.

Abstract: A battery pack including fire extinguishing equipment. The fire extinguishing equipment includes a first chamber, a second chamber, and an activation line. The first chamber stores a fire extinguishing chemical agent, the second chamber stores a gas-generating chemical agent, and the activation line extends into the second chamber to be in contact with the gas-generating chemical agent. The second chamber includes a pressure relief opening, and the pressure relief opening is in communication with the first chamber, and is configured to spray the gas in the second chamber to the first chamber. The first chamber includes a discharge opening, and the discharge opening is configured to discharge the fire extinguishing chemical agent in the first chamber after the gas generated after the gas-generating chemical agent is ignited enters the first chamber.

Abstract: Disclosed is a wrist-worn device, including a device body and a wristband. The wristband includes: a band body including two detachable ends; an installation part provided on the band body; and a memory metal wire in a shape of a long strip extending along a length direction of the band body. The band body is provided with a first installation cavity, the installation part is provided with a second installation cavity communicated with the first installation cavity, and the device body is provided in the second installation cavity; the memory metal wire is provided in the first installation cavity and passes through the second installation cavity; the memory metal wire is configured with a memory state of being annular in a natural state; and the device body is provided with a positioning groove extending along the length direction of the band body.

Abstract: Disclosed are a wristband and a wrist-worn device. The wristband includes a band body part and a memory metal part provided to the band body part. The band body part has two end portions separable from each other. The memory metal part has a memory state of being ring-shaped in a natural state, so that the band body part naturally maintains a ring shape, and the wristband naturally maintains a wearing state.

Abstract: Disclosed are a wristband and a wrist-worn device. The wristband includes a band body part and a memory metal wire. The band body part has two end portions separable from each other. The memory metal wire has a strip shape extending along a length direction of the band body part and provided to the band body part. The memory metal wire has a memory state of being ring-shaped in a natural state, so that the band body part naturally maintains a ring shape, and the wristband naturally maintains a wearing state. A first installation cavity is provided inside the band body part, and the memory metal wire is accommodated and installed in the first installation cavity.

Abstract: The present disclosure provides systems and methods for image filtering. The method may include obtaining an initial image block from a reconstructed image; determining at least one candidate image block by performing a filtering operation on the initial image block using at least one trained machine learning model; and determining a target image block based on the at least one candidate image block.

Abstract: An autonomous cleaning device and a noise reduction air duct device are provided for autonomous cleaning device. The autonomous cleaning device includes a body and a motor arranged on the body, and the noise reduction air duct device is mounted on the body. The noise reduction air duct device includes an upper housing, a lower housing and a support noise reduction structure made of elastic material. The lower housing and the upper housing enclose to form an air duct, an air inlet is arranged at a position of the air duct corresponding to the motor, and an air outlet is arranged on a side of the air duct away from the air inlet; the support noise reduction structure has a first end fixed on the lower housing, and a second end abutting against a lower surface of the upper housing.

Abstract: Embodiments of this application provide a method for displaying a two-dimensional code and an electronic device. The method is performed by an electronic device, and includes: obtaining first sensor data, where the first sensor data is collected at a first moment; if it is determined, based on the first sensor data, that a first action of a user corresponding to the first moment is a preset action, determining whether the user performs a wrist turning action within a preset duration range starting from the first moment; and displaying a preset two-dimensional code page when the user performs a wrist turning action within the preset duration range. In the method, a process of presenting a two-dimensional code by the user can be simple and efficient.

Abstract: Methods for large-scale additive manufacturing of high-strength boron nitride nanotubes (BNNT)/aluminum (Al) (e.g., reinforced Al alloy) metal matrix composites (MMCs) (BNNT/Al MMCs), as well as the BNNT/Al MMCs produced by the large-scale additive manufacturing methods, are provided. A combination of ultrasonication and spray drying techniques can produce good BNNT/Al alloy feedstock powders, which can be used in a cold spraying process.

Abstract: The present disclosure provides a method for preparing a composition including mesenchymal stem cells, extracellular vesicles produced by the mesenchymal stem cells, and growth factors, the composition prepared by the method, and use of the composition for treating arthritis. The composition of the present disclosure achieves the effect of treating arthritis through various efficacy experiments.

Abstract: Methods for large-scale additive manufacturing of high-strength boron nitride nanotubes (BNNT)/aluminum (Al) (e.g., reinforced Al alloy) metal matrix composites (MMCs) (BNNT/Al MMCs), as well as the BNNT/Al MMCs produced by the large-scale additive manufacturing methods, are provided. A combination of ultrasonication and spray drying techniques can produce good BNNT/Al alloy feedstock powders, which can be used in a cold spraying process.

Abstract: A low-carbon and low alloy hot-work die steel with a high toughness at low temperatures and a high strength at high temperatures and a high hardenability, comprises the following components: C: 0.15-0.35%, Si: 0.40-0.90%, Mn: ?0.80%, Cr: 1.50-2.40%, Ni: 2.50-4.50%, Mo: 1.00-1.60%, V: 0.10-0.40%, W: 0.20-0.90%, P: ?0.02%, S?0.02%, and a balance of Fe matrix and other inevitable impurities. The above percentages are mass percentages. The material of the present invention can have a V notch impact energy of 30 J or more than 30 J at ?40° C., a high temperature strength of 380 MPa or more at 700° C., and a hardenability of 200 mm or more to ensure the consistency of internal and external microstructures. The materials of the present invention can be applied to hot-work molds used in special working conditions that require high toughness at low temperatures, high strength at high temperatures and high hardenability.

Abstract: A system for a sandy soil landfill solid waste polluted river channel, includes a ground water interception and diversion system and a river channel ecological remediation system. The ground water interception and diversion system includes a water intake well arranged upstream of ground water in a landfill area, a buffer pool communicated with the water intake well, and a wastewater treatment system communicated with the buffer pool. The water intake well, the buffer pool, and the wastewater treatment system are communicated through a wastewater pipe. An electric wastewater valve and a variable frequency water pump are arranged on the wastewater pipe in sequence. The river channel ecological remediation system includes an impermeable layer arranged at a bottom of a river channel and ecological bank protections arranged on both sides of a river channel slope.

Abstract: The present disclosure provides a method for treating liver cirrhosis by using a composition including mesenchymal stem cells, extracellular vesicles produced by the mesenchymal stem cells, and growth factors. The composition of the present disclosure achieves the effect of treating liver cirrhosis through various efficacy experiments.

Abstract: The present invention relates to a method for preparing a modified stem cell, including the following steps: a cell culture step: culturing stem cells in a first culture medium of a culture dish at a predetermined cell density, and removing the first culture medium after a first culture time to obtain a first cell intermediate; an activity stimulation step: preserving the first cell intermediate in a freezing container having a cell cryopreservation solution, and performing a constant temperature stimulation treatment or a variable temperature stimulation treatment for at least more than 1 day; and a product collection step: after completing the activity stimulation step, placing the freezing container in an environment at a thawing temperature for thawing, and then removing the cell cryopreservation solution to obtain the modified stem cell. The modified stem cell can release at least one or more of IL-4, IL-5, IL-13, G-CSF, Fractalkine, and EGF.

Abstract: A fan-out semiconductor device includes stacked semiconductor dies having die bond pads arranged in columns exposed at a sidewall of the stacked semiconductor dies. The stacked dies are encapsulated in a photo imageable dielectric (PID) material, which is developed to form through-hole cavities that expose the columns of bond pads of each die at the sidewall. The through-hole cavities are plated or filled with an electrical conductor to form conductive through-holes coupling die bond pads within the columns to each other.

Abstract: The present disclosure discloses a blended ternary positive-electrode material, a preparation method thereof and a lithium ion battery, and relates to the field of lithium battery technologies. A temperature-sensitive precursor type material is taken as a raw material, a large-particle precursor, a small-particle precursor and lithium sources are presintered to obtain a first presintered material and a second presintered material, presintered materials and binders are then mixed, compacted and punctured to obtain a first to-be-sintered material block and a second to-be-sintered material block, the first to-be-sintered material block and the second to-be-sintered material block are loaded into a sagger together for primary sintering, and using a periphery-center regional mode or an upper-lower-layer distribution mode, the first presintered material is distributed at a periphery or an upper layer, and the second presintered material is distributed at a center or a lower layer.

Abstract: A micro-metering device with a constant flow rate, including a rotary shear valve, a mounting seat, a rotation drive assembly, an injection drive assembly and a controller. The rotary shear valve includes a valve main body and a valve spool. The valve main body is provided with a main flow channel and a plurality of branch flow channels. The valve spool is rotatably arranged inside the valve main body, and is configured to communicate the main flow channel with different branch flow channels. A pressure sensor is provided inside the valve main body, and is communicated with the main flow channel. The pressure sensor is configured for detecting a pressure inside the main flow channel. Whether the switching of the liquid path is correct is determined according to the pressure in the main flow channel.