Abstract: A high-acoustic-resistance piston motion loudspeaker disclosed in the present disclosure belongs to the field of sound-electricity conversion. The loudspeaker includes a substrate, a driving assembly, a vibrating diaphragm, a connecting assembly and a vibration cavity. The connecting assembly is not coplanar with the vibrating diaphragm, which is of a concealed connecting structure. The driving assembly is configured to drive the vibrating diaphragm to generate a piston motion. The vibrating diaphragm is located in the vibration cavity, and a displacement range of the vibrating diaphragm in a perpendicular direction is within a height range of the vibration cavity formed by a supporting structure extending in a thickness direction of a base, so as to achieve purposes of reducing air leakage and improving a sound pressure level in a working process of the loudspeaker.

Abstract: Disclosed is a hollow sulfide microsphere with enriched sulfur vacancies, which is prepared by a method comprising the steps of: dissolving cobalt nitrate and nickel nitrate in a mixed solution of N, N-dimethylformamide and acetone with an equal volume; then adding a chelating agent thereto, subjecting a resulting mixture to a solvothermal reaction to obtain a coordination polymer microsphere; dissolving the coordination polymer microsphere and a sulfurization agent in an organic solvent, and reacting to obtain a hollow sulfide microsphere; and subjecting the hollow sulfide microsphere to reduction treatment with sodium borohydride, centrifuging, washing and drying to obtain the hollow sulfide microsphere with enriched sulfur vacancies having a particle size of 1-2.5 ?m, a shell thickness of 15-30 nm and a specific capacity of the material of 763.4 C g?1 (current density is 1 A g?1).

Abstract: One or more embodiments of the present specification provide a method and device for capacity degradation prediction of a lithium-ion battery. The method comprises the following steps: acquiring an original battery discharge capacity; decomposing the original battery discharge capacity through a predetermined mode decomposition method to obtain battery discharge capacities composed of a plurality of different frequency signals; inputting the respective frequency signals into a pre-constructed capacity prediction model to obtain capacity prediction results corresponding to the respective frequency signals; selecting capacity prediction result that satisfies a predetermined relevance condition corresponding to the respective frequency signals; and reconstructing the finally predicted battery discharge capacity according to the capacity prediction result that satisfies the predetermined relevance condition.

Abstract: One or more embodiments of the present description provide a method and device for risk prediction of thermal runaway in LIB. The method includes: acquiring knowledge of a mechanism for thermal runaway in LIB; describing an evolution process of thermal runaway in LIB by adopting a fault tree; mapping a fault tree structure to a dynamic Bayesian network model for thermal runaway in LIB to obtain quantitative results of a risk of thermal runaway in LIB; and taking the quantitative results of a dynamic Bayesian network as inputs of a machine learning model to obtain prediction results of the risk of thermal runaway. By using the method in the present embodiment, an evolution trend of battery thermal runaway can be predicted by fusing multiple thermal runaway causes and multi-source data, and thus, the prediction results are relatively accurate.

Abstract: A temperature-sensitive automatic rapid gas generation fire extinguishing device is provided, including a box body; a plurality of heat absorption fire extinguishing units are placed on an inner side wall of the box body, and a first trigger unit is arranged between one of the heat absorption fire extinguishing units close to the first baffle and the inner side wall of the box body; the one of the heat absorption fire extinguishing units triggers the first baffle to move down through the first trigger unit, and a relatively closed space is formed in the box body; a plurality of gas generation fire extinguishing units are placed on an inner side wall of the box body, and a second trigger unit is arranged between one of the gas generation fire extinguishing units close to the second baffle and the inner side wall of the box body.

Abstract: A self-powered wireless keyboard by modifying the structure of a traditional membrane keyboard having a volcanic crater structure. Not damaging the original membrane keyboard structure, a micro magnet core is installed inside a cylindrical protrusion block under the key cap as a mover of the induction power generation device, and an induction coil is wound in a key slot of the keyboard base as the stator of the induction power generation device. In this way, when each key is pressed, it will produce induction current. A layer of flexible solar cell can be laid on the upper surface of the key, which can generate electricity by collecting the light energy in the surrounding environment during the time of daily illumination.

Abstract: A control device for reducing and homogenizing welding residual stress by acoustic waves, comprising: a fixing tool having two rows of through holes; a plurality of ultrasonic transducers each having a body and a conical horn transmitting portion at a lower end of the body, wherein lower ends of the horn transmitting portions are fixedly connected with flanges, the horn transmitting portions of the ultrasonic transducers extend into respective through holes of the fixing tool to be in contact with welded parts below the fixing tool, the flanges are fixed to the fixing tool by bolts, and the two rows of through holes are arranged both sides of a welding seam of the welded parts; and a driving device for driving the ultrasonic transducers to operate. A corresponding control method is also provided. The control device can be used to control residual stress at the welding seam of steels.

Abstract: The present invention discloses a biaxial supporting device for a rotary opposed piston engine, comprising a cylinder body, a fixing component, a thick axle and a thin axle; the interior of the cylinder body has a cavity; the fixing component is fixed on the outer side wall of the cylinder body; the thick axle is provided with a through hole coaxial with the first axle hole, and is rotatably connected with the through hole; the thin axle is in transition fit with the through hole of the thick axle, and is rotatably connected with the fixing component. The present invention has simple structure, can effectively reduce a diameter difference of two axles to ensure the relatively small diameter of the thick axle and the relatively high strength of the thin axle, and can effectively realize biaxial support of the rotary opposed piston engine.

Abstract: The present disclosure relates to a risk early warning method and system for hydrogen leakage, and relates to the field of hydrogen leakage. The method includes: obtaining ventilation information of a hydrogen-related area; carrying out grid division on a pipeline system of the hydrogen-related area to obtain a gridded pipeline system; determining a risk coefficient corresponding to each grid of the gridded pipeline system according to leakage sources of the pipeline system; determining a high-risk region by means of a jet cone model according to the risk coefficients; determining a medium-risk region, a low-risk region and a safe region according to the risk coefficients and the ventilation information; and carrying out risk early warning according to the high-risk region, the medium-risk region, the low-risk region and the safe region.

Abstract: The present disclosure relates to a smart battery. The smart battery includes a battery shell, layered cells, a positive electrode, a negative electrode, an embedded multi-source sensor group and an intelligent chip. The smart battery can detect the temperature and the pressure of the core of the battery and the current of the battery in real time by using the intelligent chip and the embedded multi-source sensor group, thereby realizing a real-time monitoring of the working state and safety state of the battery, and improving a safety and the reliability of the battery on the basis of realizing the self-sensing function of the battery. The modification to the conventional battery structure by adding the intelligent chip and the embedded multi-source sensor group makes up the gap in research and development, manufacturing and production of the smart battery on the premise of ensuring that the battery volume remains unchanged.

Abstract: A wireless power transfer (WPT) system regulation method and system for implementing zero voltage switching (ZVS) in a wide power range are provided. The method includes: determining, according to a topology structure of a WPT system and based on a linear state equation, a phase -shift angle boundary and a switching frequency boundary of an inverter that meet ZVS; fixing a switching frequency at a resonance frequency of the WPT system, and determining, in a phase -shift manner, a phase-shift range and a corresponding first voltage output range for implementing ZVS; determining a frequency variation range of a frequency modulation method; determining an optimal switching frequency based on corresponding switching frequencies and phase-shift angles that meet ZVS at different expected output voltages of the WPT system; determining a second voltage output range for implementing ZVS at the optimal switching frequency; and regulating the WPT system by using different regulation methods.

Abstract: A method for controlling hybrid scanning based on a miniature reflecting device, which includes: loading parameters for determinant scanning and circular scanning, setting a scanning start point, and performing determinant scanning; performing low-pass filtering on received sampling data to filter an outlier in a sampling process, and performing singular value determining, to determine whether there is a valid connected domain within a scanning field of view; determining, as a target of interest, a valid connected domain with a maximum quantity of singular values, and obtaining a geometric center of the target of interest by calculating an average value of driving voltages corresponding to the singular values; performing circular scanning by using the geometric center as a scanning center, determining, in a process of scanning an outermost ring, whether singular values are centrosymmetrically distributed on the ring, to fine-tune the scanning center till the singular values are centrosymmetrically distributed

Abstract: Disclosed are a protection equipment, system and method for the destruction of explosives. The protection equipment for the destruction of explosives includes four modules: an inner fence, an outer fence, an anti-leakage fence and a top cover. The modular equipment takes an overall nonmetal flexible composite structure, and the individual modules are light in weight and convenient to operate. It can be operated by two persons or a single person. A protective effect can be achieved during destruction of explosives by using the protection equipment, and even if the explosives explode during destruction, it will not cause injury to surrounding personnel. A protection system for explosive destruction based on the protection equipment can be used to destroy unexploded bomb or explosives under protective conditions, thereby achieving rapid emergency disposal without making contact with the explosives.

Abstract: The present disclosure relates to a risk early warning method and system for hydrogen leakage, and relates to the field of hydrogen leakage. The method includes: obtaining ventilation information of a hydrogen-related area; carrying out grid division on a pipeline system of the hydrogen-related area to obtain a gridded pipeline system; determining a risk coefficient corresponding to each grid of the gridded pipeline system according to leakage sources of the pipeline system; determining a high-risk region by means of a jet cone model according to the risk coefficients; determining a medium-risk region, a low-risk region and a safe region according to the risk coefficients and the ventilation information; and carrying out risk early warning according to the high-risk region, the medium-risk region, the low-risk region and the safe region.

Abstract: Provided is a configuration construction and attitude control method for a pyramid deorbit sail. By taking into consideration environmental perturbation like atmospheric resistance perturbation and non-spherical earth perturbation, a dynamics model featuring three-dimensional orbit-and-attitude coupling based on position vectors and quaternion descriptions, the deorbit sail is taken as a rigid body, a spacecraft body is taken as a mass point, airflow obstruction is considered in the windward area, thereby improving the precision of the dynamics model; based on this model, the law of influence of the configuration parameters in the deorbit sail, such as a cone angle and a strut length, on the attitude stability and deorbiting efficiency of the spacecraft in different cases is analyzed, the configuration parameters of the pyramid deorbit sail system are analyzed and optimized according to the derived law, so as to obtain a pyramid deorbit sail achieving high attitude stability and high deorbiting efficiency.

Abstract: A device and a method for ultrasonic detecting a mechanical member based on magnetic fluid coupling. The device comprises a magnetic field generating apparatus, magnetic fluid and an ultrasonic probe. The magnetic field generating apparatus has a cylindrical structure, into which the magnetic fluid is injected, where an upper portion of the apparatus is provided with the ultrasonic probe a front end that vertically extends into a liquid level of the magnetic fluid, and a bottom portion of the apparatus covers a detected position of a member under detection. The magnetic fluid at least contains magnetic suspension particles and oil-based or water-based liquid. With the device and the method, the ultrasonic probe is coupled with the member under detection to realize ultrasonic detecting of the service stress of the member under detection.

Abstract: A mechanical energy-based self-powering counting system is provided. The system includes an electromagnetic power generator, a count measuring circuit, a count energy supply circuit, a controller and a wireless transmission module. The electromagnetic power generator is driven by an external device and produces an electric signal and outputs the electric signal to the controller after passing it through the count measuring circuit. The controller processes the received signal, updates a count according to certain programming rules and sends data to the wireless transmission module. The energy from the electromagnetic power generator flowing through the count measuring circuit can supply power to the controller. An energy storage module in the count energy supply circuit performs voltage feedback on the controller. The controller monitors the voltage of the energy storage module to control whether it enters a charging state.

Abstract: Disclosed is a multi-mode electro-hydraulic brake boosting system and a control method thereof. When the boosting system fails, an emergency mechanical braking mode is achieved through structural redundancy, in a normal boosting mode, the system has a general braking mode and an emergency braking mode according to the strength requirements of a brake, and a general brake boosting mode and an emergency active pressurizing mode are controlled, respectively. Accurate boosting can be provided in the general braking process so that the pressure of a brake master cylinder can accurately follow target pressure, pressure buildup of the brake master cylinder can be completed more quickly in the emergency braking process, braking force is output to the maximum extent, the system response time of an emergency braking working condition is shortened, the braking capacity is improved, and traffic accidents are avoided.

Abstract: A rotary-transmission-target microfocus X-ray source and an X-ray generation method based on the rotary-transmission-target microfocus X-ray source are provided. The X-ray source comprises a chamber, and an electron beam system is installed in the chamber. The electron beam system is arranged on a same side as an anode target rotating shaft. A motor in a rotary anode target system drives an anode target to rotate through a bevel gear transmission device. The microstructure of a target is designed. An electron beam emitted by the electron beam system vertically bombards the metal target of the rotating anode target. A cooling system is configured to cool the anode target.

Abstract: A device for reducing and homogenizing residual stress of a metal frame including a substrate, a frame fixing device and ultrasonic vibrators. A groove with an upward opening is provided in the middle of the substrate, and a shape enclosed by vertical side walls of the groove matches a shape of an outer frame of a metal frame to be processed. A plurality of through holes that are horizontally diverged are arranged around the side walls of the groove, and the through holes are vertically intersected with the groove. The ultrasonic vibrators are provided on the substrate and front ends of the ultrasonic vibrators extend into respective through holes to abut against the metal frame in the groove. The frame fixing device is also arranged in the groove where the metal frame is located, after the metal frame to be processed is placed in the groove.