368 results about "Medium frequency" patented technology

The invention discloses a Fourier transform and S transform combined battery impedance spectroscopy measurement method and device, and aims to improve the precision, speed and reliability of impedance measurement of a battery energy storage system. According to the method, a multi-frequency component excitation signal is generated through a controllable current source, and current and voltage response signals of a battery are synchronously acquired and are respectively input into a Fourier transform module and an S transform module for frequency domain analysis. The Fourier transform module extracts impedance spectrums of low and medium frequency bands, and the S transform module extracts impedance spectrums of medium and high frequency bands through Gaussian window time-frequency analysis. And a data fusion algorithm is adopted to perform composite processing on results of the two modules, including a direct selection method, an arithmetic average method, an amplitude and phase calibration method and a weighted average method, so that smooth transition and optimization between frequency bands are realized, and finally the electrochemical impedance spectrum is generated. Through collaborative analysis of Fourier transform and S transform, parameter optimization and a fusion algorithm, the efficiency and accuracy of impedance spectroscopy measurement are remarkably improved, and the method is suitable for rapid monitoring and diagnosis of the battery state.

The invention belongs to the technical field of noise reduction devices, and discloses an acoustic black hole combined noise reduction structure embedded with a micro-perforated structure. The device comprises an acoustic black hole cavity, a side cavity and a micro-perforated hole for communicating the acoustic black hole cavity with the side cavity, the acoustic black hole cavity comprises a thin plate array and an acoustic black hole cavity shell; the thin plate array is composed of a plurality of thin plates with round holes in the centers, the outer sides of the thin plates are fixed to the inner side of the acoustic black hole cavity shell, the thin plates are arranged at equal intervals, the centers of the thin plates are coaxial, the inner diameters of the thin plates are arranged in a monotonically decreasing or increasing mode, and an acoustic black hole structure is formed. The side cavity is located outside the acoustic black hole cavity and wraps the acoustic black hole cavity to form a closed space. The low-frequency, medium-frequency and high-frequency full-band noise reduction device is compact and simple in structure, convenient to use, diversified in form, capable of solving the noise reduction problem of low frequency, medium frequency and high frequency of 150 Hz or above, capable of improving the sound energy dissipation efficiency of system noise and wide in application prospect.

The invention provides an intelligent battery sorting method integrating impedance characteristics and deep learning. The method comprises the following steps: acquiring battery impedance data through an electrochemical workstation, drawing an electrochemical impedance spectroscopy (EIS), and extracting impedance characteristics of a medium-frequency region; a 25-dimensional impedance coupling feature space is innovatively constructed, a dual-network differentiated feature selection strategy (IC-GRU) is adopted, a main network selects 12 features with the highest correlation, a boundary expert network selects 10 features with the highest correlation and additionally constructs 5 boundary sensitive features, and finally, the main network selects 12 features with the highest correlation. And establishing an impedance coupling sensing gating circulation unit network to realize accurate prediction of the state of health (SOH). And performing four-stage sorting on the SOH result predicted by the IC-GRU through a random forest algorithm (RF). According to the method, more accurate SOH prediction is realized through deep learning guided by a physical mechanism, the battery pack health state sorting precision and consistency are improved, and an intelligent solution is provided for new energy automobile battery life management.

The invention belongs to the technical field of acoustic measurement, and particularly relates to an acoustic flow tube test platform and a test method thereof, transmission loss measurement of an acoustic metasurface under a flow field working condition is carried out through the constructed acoustic flow tube test platform, and a test piece mounting tube of the acoustic flow tube test platform can be used for mounting most acoustic metasurface test pieces. The related technical research of the acoustic metasurface is facilitated; meanwhile, the test platform creates a flow acoustic measurement environment, weakens the turbulence pressure disturbance influence by means of a reference signal, self-spectrum and cross-spectrum signal processing method based on a scattering matrix theory, and adopts a double-load method to perform parameter solution on a scattering matrix and calculate a class of acoustic characteristics of the acoustic metasurface to be tested, thereby solving the problem of low Mach number (llt; the method can be used for measuring the transmission loss of the acoustic metasurface in the low and medium frequency range (300-2000Hz) under the tangential flow (0.3 Mach), and the technology can be widely applied to the fields of unmanned aerial vehicles, eVTOLs, household appliances, automobiles and the like with noise reduction requirements.

The invention belongs to the technical field of artificial intelligence and data analysis, and discloses a time sequence prediction method and device based on wavelet transform and a large language model. The time sequence prediction method comprises the following steps: obtaining known historical time sequence data; based on the obtained known historical time sequence data, performing time sequence prediction in a future time period by using the trained time sequence prediction model to obtain predicted values of three frequency domain components of low frequency, intermediate frequency and high frequency; adding the obtained predicted values of the low frequency domain component, the intermediate frequency domain component and the high frequency domain component, and carrying out inverse normalization processing on the added result to obtain a final time sequence prediction result; the time sequence prediction model comprises a wavelet decomposition module, a backbone network of a pre-training large language model and a prediction head. According to the technical scheme disclosed by the invention, the accuracy of time sequence prediction can be remarkably improved.

The invention belongs to the technical field of wind power prediction, and particularly discloses an ultra-short-term wind power prediction method, which comprises the following steps: S1, obtaining an original wind power sequence; s2, decomposing the wind power signal into a series of sub-signals by adopting a CEEMDAN signal decomposition algorithm; s3, denoising and reconstructing the IMF1 component by adopting an improved singular spectrum analysis (SSA) algorithm; s4, the permutation entropy of each component is calculated, the components are divided into high frequency, medium frequency and low frequency according to the permutation entropy, the high frequency is combined together, and the medium frequency and the low frequency are combined together; and S5, sending the data into the established TCN-GRU prediction network, and superposing the results of the two prediction networks to obtain a final prediction result. According to the ultra-short-term wind power prediction method, the prediction performance of the model is better than that of a traditional model and other models based on TCN, high-precision and high-stability prediction of the wind power plant power is achieved, and decision support is provided for operation management of the wind power plant.

The invention discloses an offshore wind power frequency conversion gathering and sending control method, device and system based on onshore integration, and belongs to the technical field of power transmission and distribution of power systems, and the method comprises the steps: converting first AC electric energy generated by an intermediate-frequency / power-frequency wind power plant into first DC electric energy through an offshore converter station; the first direct-current electric energy is transmitted to a land integration station through a direct-current submarine cable; second alternating-current electric energy generated by the low-frequency wind power plant is transmitted to the land integration station through a low-frequency alternating-current submarine cable; and converting the second alternating-current electric energy into second direct-current electric energy in the land integrated station, carrying out collection and power frequency conversion on the first direct-current electric energy and the second direct-current electric energy, and transmitting power frequency alternating-current electric energy obtained after conversion to a land power grid. Therefore, by implementing the application, the problem that the electric energy cannot be transmitted at low cost due to the fact that it is difficult to directly send the electric energy of different frequencies out of the system for topological combination in the prior art can be solved.

The invention discloses a six-degree-of-freedom micro-vibration table in-situ calibration device and method, and the device comprises a six-degree-of-freedom micro-vibration table top, a mounting platform, a linear vibration calibration unit, an angular vibration calibration unit, a coordinate positioning tool, a coordinate positioning tool fine adjustment mechanism, and a data collection and analysis system upper computer. The linear vibration calibration unit comprises an acceleration measurement unit and a vibration displacement measurement unit, the acceleration measurement unit is used for in-situ calibration of linear vibration parameters of the test system, and the vibration displacement measurement unit is used for in-situ calibration of vibration displacement parameters of the test system; and the angular vibration calibration unit is used for carrying out in-situ calibration on angular vibration parameters of the test system. According to the invention, on-site in-situ calibration of three-axis vibration and three-axis angular vibration of the six-degree-of-freedom micro-vibration table is realized, calibration in a low and medium frequency, micro-amplitude and multi-axis angular compound vibration state is realized through the acceleration sensor and the angular vibration sensor, and the six-degree-of-freedom micro-vibration table has the advantages of low cost, fast response and high reliability.

The utility model discloses a dustproof and rainproof medium frequency power supply cabinet, which relates to the technical field of power supply cabinets, and comprises a power supply cabinet body and heat dissipation grooves symmetrically arranged on both sides of the power supply cabinet body. A clamping plate is elastically pulled by a tightening spring to stably fix the dust cover, which is convenient for subsequent disassembly and installation. The dust cover covers the heat dissipation groove, which not only plays a role of dustproof protection, but also plays a role of shielding rainwater splashing in. When the rainwater is heavy, the splashing rainwater drops into the waterproof cover and is collected by it. The waterproof cover is provided with waterproof cover ventilation holes, and the openings are gradually increased from bottom to top. While collecting the rainwater, the normal heat dissipation of the device will not be hindered. When the water level detection head detects that the water level in the waterproof cover reaches a predetermined point, a signal is sent to light up the alarm light, and the staff can drain the water from the waterproof cover through a drain pipe, thereby further improving the waterproof effect of the device when it encounters heavy rain when used outdoors.

The invention discloses an intermediate frequency electro-therapeutic apparatus, which comprises a controller and a waveform synthesis circuit, and is characterized in that the waveform synthesis circuit comprises a first amplitude adjusting circuit, a second amplitude adjusting circuit and a synthesis adjusting circuit, and the controller generates a first PWM signal according to the overall amplitude information; the first amplitude adjusting circuit performs amplitude modulation processing on an input original waveform according to the first PWM signal to generate a first analog waveform signal; the controller obtains amplitude information corresponding to the frequency of the modulation waveform by using the phase accumulator, and generates a second PWM signal; a second amplitude adjusting circuit performs multiplication operation on the second PWM signal and the first analog waveform signal to obtain a second analog waveform signal and obtain an inverted waveform signal; the controller obtains amplitude information corresponding to the frequency of the fundamental frequency waveform by using a phase accumulator, and generates a third PWM signal; and the synthesis adjusting circuit performs multiplication operation on the third PWM signal and the second analog waveform signal or the inverted waveform signal to generate an intermediate frequency treatment waveform.

The invention relates to the technical field of robot control. A humanoid robot gait generation system based on hierarchical control is characterized by comprising a multi-layer control system operating at different refresh frequencies, and the multi-layer control system comprises a high-layer gait and trajectory planning layer operating at a low frequency and used for generating a macroscopic motion instruction; the middle-layer whole-body motion optimization layer runs at medium frequency, serves as a bridge of high-layer planning and bottom-layer control and is used for converting expected plantar and trunk tracks into reference motion of all joints of the whole body; the bottom joint servo control layer runs at the highest frequency and is responsible for accurately tracking a joint-level instruction output by the whole-body motion optimization layer; the state sensing and feedback closed-loop layer is used for feeding back state information, obtained in real time, of the body state of the robot to all the layers, providing a basis for track re-planning of a high layer and providing a real-time state initial value for optimization of a middle layer; and a feedback signal is provided for servo control of a bottom layer.

The invention discloses a medium-frequency induction furnace molten metal leakage automatic cut-off system based on temperature monitoring, and relates to the technical field of industrial molten metal monitoring, and the system comprises a data acquisition module which is used for obtaining historical temperature data under different working conditions in a high-temperature and high-pressure environment by constructing a molten metal temperature feature library, and sending the historical temperature data to a data processing module; the data classification module is used for classifying and marking various flow scenes to form an initial data set containing a temperature distribution rule in a normal flow state and obtain reference data for subsequent mode definition, and the risk assessment module is used for generating a risk level according to the initial data set and determining the risk degree of a current flow state; according to the medium-frequency induction furnace molten metal leakage automatic cut-off system based on temperature monitoring, molten metal flowing abnormity is found in time, the risk degree is accurately evaluated, monitoring parameters are automatically adjusted to deal with the high-risk state, and the safety and controllability of the molten metal production process are effectively improved.

The invention discloses a photovoltaic power ultra-short-term prediction method, system and device and a storage medium, and relates to the technical field of new energy prediction. The method comprises the following steps: constructing an improved ensemble empirical mode decomposition algorithm to decompose original photovoltaic power data, and distinguishing and reconstructing a plurality of decomposed intrinsic mode functions to obtain reconstruction sequences of high, medium and low frequency components; for high-frequency and intermediate-frequency components, carrying out dynamic denoising by adopting an extended Kalman filtering algorithm; and inputting the original data, the low-frequency component, the denoised high-frequency component and the denoised intermediate-frequency component into a WTConv1d module, extracting multi-scale features through a wavelet filter and convolution operation, and inputting a multi-dimensional input matrix constructed by the multi-scale features and meteorological data into a Transform model for prediction. According to the method, noise interference can be effectively suppressed, multi-time scale feature expression is enhanced, and a self-attention mechanism is fully utilized to capture a cross-scale dependency relationship, so that the prediction precision and stability are improved.

The invention belongs to the technical field of new energy storage, and relates to a full-life-cycle capacity optimization configuration method for a photovoltaic-hybrid energy storage system. A traditional configuration method of photovoltaic energy storage does not accurately consider energy storage characteristics and whole life cycle cost, and is poor in economical efficiency and reliability. According to the method, a constraint model taking the minimum sum of modal estimation bandwidths as a target is constructed based on VMD decomposition, photovoltaic power is decomposed into different components, sorting is carried out based on modal center frequencies, and a differential power distribution strategy of high frequency-super capacitor, intermediate frequency-lithium battery and low frequency-vanadium battery is provided; the method achieves the precise matching of the energy storage technology and the power fluctuation characteristics, constructs a target function covering the whole life cycle investment, operation and maintenance, replacement and scrap cost, carries out the quantitative screening of an economical efficiency optimal scheme, and solves the limitation that a frequency demarcation point does not have a clear basis. Compared with two types of energy storage schemes which are divided into'high frequency and low frequency ', the'low-medium-high frequency' scheme is lower in comprehensive cost, and a technical scheme is provided for capacity configuration of the photovoltaic energy storage system.

The invention provides an intermediate frequency furnace cooling water system real-time monitoring and early warning platform based on the Internet of Things, and the platform comprises a sensing layer which is used for collecting the operation parameters of each water path of a cooling water system and the operation state of monitoring equipment in real time, and judging whether the cooling water system and the monitoring equipment are abnormal or not; the network layer is used for preprocessing the collected operation parameters and uploading the operation parameters to the platform layer; the platform layer is used for analyzing the uploaded data and optimizing and adjusting operation parameters of the cooling water system according to an analysis result; and when the cooling water system is abnormal, an abnormal early warning notice is sent to a communication end of related personnel by using a wireless communication technology. According to the invention, all-weather and all-directional remote online monitoring of the cooling water system of the intermediate frequency furnace is realized, the operation safety and stability of the cooling water system are effectively improved, the parameters of the cooling water system are optimized and adjusted according to the monitoring data, and the energy consumption and maintenance cost of cooling of the intermediate frequency furnace are reduced.

The invention provides a wireless bladder volume monitoring system based on inductive coupling. The wireless bladder volume monitoring system is composed of a passive LC sensor unit tightly attached to the bladder, an external reading coil integrated on clothes or a belt, and a portable impedance measuring unit arranged in a pocket of the clothes. According to the system, the high penetrability of low and medium frequency scanning signals is utilized, wireless monitoring of the in-vivo bladder state is achieved through electromagnetic coupling between the passive LC sensor unit and the external reading coil, and the influence of relative pose changes between the passive LC sensor unit and the external reading coil on the measurement result can be effectively overcome. According to the bladder volume wireless passive real-time monitoring system, the system resonant frequency of the passive LC resonant unit is obtained by continuously detecting the impedance of the input end of the external reading coil, and then the bladder volume wireless passive real-time monitoring system easy to wear is achieved, has the advantages of being simple in structure, high in reliability and portable and is suitable for long-term monitoring scenes.

The invention provides a Brown relaxation dominated magnetic nanoparticle nonlinear biological information parameter estimation method. The method comprises the following steps: putting a container of a magnetic nanoparticle sample into a to-be-detected object area; applying low and medium frequency alternating current magnetic field excitation to the magnetic nanoparticle sample; collecting magnetization response information of the magnetic nanoparticle sample in real time and extracting harmonic amplitude information from the magnetization response information; carrying out series expansion on the Fokker-Planck equation by using a disturbance expansion method, and deducing a harmonic analytical expression under the Brown relaxation condition; respectively establishing a corresponding temperature estimation model and a hydrodynamic diameter estimation model on the basis of the harmonic analytical expression; respectively substituting the measured harmonic amplitude information into a temperature estimation model or a hydrodynamic diameter estimation model based on a harmonic analytical expression; and respectively solving an equation set formed by the temperature estimation model or the hydrodynamic diameter estimation model to obtain temperature information or hydrodynamic diameter information. According to the invention, the measurement precision and the time resolution of the magnetic nanometer temperature measurement and biomarker identification tool can be improved.

The invention relates to the technical field of sound insulation materials, in particular to a high-performance sound insulation material for buildings and a preparation method thereof, and the high-performance sound insulation material comprises the following raw materials in parts by weight: 60-80 parts of polypropylene, 15-25 parts of filler, 10-20 parts of talcum powder, 5-15 parts of flexibilizer, 0.2-1 part of antioxidant and 0.2-0.4 part of light stabilizer. According to the invention, the SEBS with high damping performance is utilized to provide a main viscoelastic effect, and the density performance of the material can be directly increased by combining the barium sulfate material with high density, so that the low and medium frequency sound insulation function is improved, and the hollow glass beads can utilize the spherical surfaces to cause scattering and refraction of sound waves and disturb the propagation direction of the sound waves in the hollow glass beads; meanwhile, in cooperation with the high radius-thickness ratio state of the mica sheet, sound waves are further dispersed and refracted in combination with the hollow glass beads, the conduction path of the sound waves is prolonged, and therefore the medium-high frequency sound insulation performance is improved, and the sound insulation performance of the material is effectively improved.

The invention relates to a fringe projection high-reflection surface phase unwrapping method based on frequency reuse. The fringe projection high-reflection surface phase unwrapping method comprises the steps of collecting a multi-frequency fringe image and dividing the multi-frequency fringe image into an overexposure area and a non-overexposure area, solving a wrapped phase in the non-overexposure area by adopting a generalized phase shift method, obtaining an initial unwrapping phase based on a multi-frequency heterodyne algorithm, and performing block filtering and interpolation processing to obtain a fringe projection high-reflection surface phase unwrapping phase. A continuous unwrapped phase containing a high-reflection area is obtained, a complementary Gray code consistent with a wrapped phase period is constructed in combination with a multi-threshold constraint and is used for correcting the stripe level of an overexposure area, brightness attenuation design is further carried out on low and medium frequency stripes, frequency reuse is achieved, and the high-reflection area is obtained. Obtaining an unwrapped phase of an overexposure point in a non-high-frequency stripe and mapping the unwrapped phase to a high frequency; the method comprises the following steps of: extracting and fusing a wrapped phase by adopting one-dimensional Fourier and Hilbert transform for areas with overexposure of each frequency, and selecting and inhibiting spectrum leakage through a complete period, so that effective correction of the wrapped phase and stripe level of an overexposure point is realized, and a reliable unwrapped phase is obtained.

The invention provides a multimode radio frequency power amplifier module, a radio frequency chip and a mobile terminal. The module comprises two power amplifiers, four switching circuits and a control circuit, an input GSM low-frequency-band radio-frequency signal and a low-frequency-band radio-frequency signal of other communication systems are input into the low-frequency-band power amplifier through the first input switch circuit, and the output of the low-frequency-band power amplifier is connected with one of the low-frequency-band radio-frequency output ports through the first output switch circuit. An input GSM high-frequency-band radio frequency signal and a medium-frequency-band radio frequency signal of other communication systems are input into the medium-frequency-band power amplifier through a second input switch circuit, and the output of the medium-frequency-band power amplifier is connected with one of the medium-frequency-band radio frequency output ports through a second output switch circuit; and the control circuit provides proper working voltage for the low-frequency-band power amplifier and the middle-frequency-band power amplifier respectively. The integration level of the radio frequency amplifier module is improved, the area is reduced, and the cost of the mobile terminal is reduced.

The invention discloses a three-frequency-band dual-polarization coaxially-distributed indoor distribution antenna, and relates to an antenna. Comprising a first dielectric plate, a low-frequency symmetrical dipole antenna, an intermediate-frequency directional diagram repairing strip-shaped metal structure, a high-frequency directional diagram repairing strip-shaped metal structure, an intermediate-frequency decoupling strip-shaped metal structure, a high-frequency decoupling U-shaped metal structure, a high-frequency decoupling C-shaped groove structure, a low-frequency feeder line and a low-frequency coaxial line, the antenna comprises a first dielectric plate, a second dielectric plate, an intermediate-frequency patch antenna, a repaired high-frequency directional diagram gap annular metal structure, an intermediate-frequency feed copper column, a non-metallization cube hole, a third dielectric plate, a high-frequency patch antenna, a high-frequency feeder line, a high-frequency coaxial line, a fourth dielectric plate, a metal floor, an intermediate-frequency feeder line and an intermediate-frequency coaxial line. The overall profile of the antenna is not increased, the low-frequency symmetrical oscillator antenna works normally, and distortion directional diagrams of the intermediate-frequency patch antenna and the high-frequency patch antenna are repaired. And the port isolation degrees of low-intermediate frequency, low-high frequency and medium-high frequency are all below-20dB, and the directional diagram repairing and decoupling performance is good.

The invention relates to an oil outlet control assembly, a rotary machine, a compressor and an air conditioner in the technical field of air conditioners, the oil outlet control assembly comprises a shell, a control part and a damping assembly, and the damping assembly is designed to limit the corresponding position of the control part in a high-speed rotating state and a low-speed rotating state; therefore, the control piece can close part of the oil hole sets in the high-speed rotating state to reduce the oil spitting amount of the compressor, namely, the oil spitting amount of the compressor is ingeniously controlled along with frequency conversion of the compressor through cooperation of the control piece and the damping assembly, so that the oil spitting amount is not affected when the compressor operates at low and medium frequencies, and the service life of the compressor is prolonged. The mass flow rate of refrigerants in the compressor and the refrigerating capacity of the compressor are correspondingly kept, when the compressor operates at high frequency, the oil spitting amount is reduced, oil lubrication of a pump body assembly of the compressor can be normally maintained, meanwhile, refrigerant oil participating in circulation in the air conditioning system is reduced, an oil film covering the inner wall of an air conditioning system pipeline is reduced, and the heat exchange efficiency of the air conditioning system is effectively improved.

The utility model discloses a buried pipeline leak detection device, which comprises a sound acquisition device and a sound generating device, the sound generating device is led in from an upper branch of a buried pipeline, floats into the buried pipeline and can flow along with water flow in the pipeline, the sound generating device is provided with generating equipment, and the generating equipment is connected with the sound acquisition device. Low and medium frequency sound can be emitted; the sound collection device is located on the ground and can detect the frequency emitted by the sound generation device. When pipeline leakage exists, the sound generating device can flow to the leakage position along with water flow, low and medium frequency sounds with different frequencies are detected through the sound collecting device, good penetrability is achieved, attenuation of the sounds in soil is weakened, and the detection accuracy can be improved by detecting the sound with the specific frequency; and meanwhile, interference of environmental noise on detection can be effectively reduced, accurate and rapid positioning of the pipeline leakage point is achieved, and the construction amount is reduced.

Technology for wireless transmission of messages to remote receiving devices is disclosed. The technology includes receiving a message for transmission, determining transmission parameters for transmission of the message, and transmitting the message to a remote receiving device according to the determined transmission parameters. The technology may also include encoding the message to effect message latency and may be employed for message transmission via the ionosphere or other atmospheric layer at frequencies in the Medium Frequency (MF), High Frequency (HF), or Very High Frequency (VHF) spectrum. Further, the disclosed technology may be employed for message transmission to effect low latency financial transaction execution, such as high speed high frequency trading.

The present application relates to a medium frequency induction heating to forging blanking system, which belongs to the technical field of blanking systems, and includes a slide bracket and a slide rail, wherein the slide rail is tilted and arranged on the slide bracket; further includes a material receiving barrel, a flip drive source and a flip frame, wherein the flip drive source is arranged in the slide bracket, the material receiving barrel is arranged on the flip frame, and the flip drive source is used to drive the flip frame to flip; the driving assembly is used to drive the clamping assembly to move along the X, Y, and Z axes, and the clamping assembly includes a clamping arm, a first clamping block and a second clamping block, wherein the first clamping block is fixed on the clamping arm, the second clamping block is slidably connected to the clamping arm, and the second clamping block moves in a direction toward or away from the first clamping block. The present application has the beneficial effects of improving the consistency of multiple flipping angles during the automatic blanking process of the material blocks, reducing the position deviation generated when multiple material blocks are blanked, reducing the possibility of failure during automatic blanking, improving the smoothness of the blanking process, and thus improving the processing efficiency.

The invention discloses an acoustic metamaterial suitable for full-band coupling noise reduction of a large-curvature aircraft cabin, and relates to the technical field of aircraft noise reduction, the acoustic metamaterial comprises a core body layer, two panel layers which are located on two sides of the core body layer and have different thicknesses, and two hard frame layers located between the core body layer and the two panel layers, the hard frame layer is formed by attaching a plurality of hard frames with hollow patterns to the inner surface of the panel layer in a discrete distribution mode. The technical problems that when a traditional acoustic material is installed on a large-curvature surface, a supporting structure is complex, the low and medium frequency noise reduction efficiency is low, and full-band noise cannot be covered are solved, the acoustic metamaterial provided by the invention is installed by being matched with the large-curvature surface in an aircraft cabin, meanwhile, a multi-order modal vibration response and structural damping coupling mechanism is utilized, and the noise reduction performance of the acoustic metamaterial is improved. The low-frequency noise reduction limitation is broken through, low-frequency, medium-frequency and high-frequency full-band noise isolation is covered, cutting is convenient, and the cabin space is not occupied.

This invention discloses a medium-frequency heating quenching and forming device for steel pipe clamps, belonging to the field of quenching and forming technology. It includes a base plate with a supporting leg installed at the lower corner. A medium-frequency heating coil is installed at the upper end of the base plate. A feeding mechanism is provided on one side of the upper end of the base plate, and a spray quenching mechanism is provided on the other side. The feeding mechanism includes a second cylinder. A connecting block is installed on the side of the base plate, and a second piston rod is installed at the output end of the connecting block. A slider is installed at the other end of the second piston rod. A slide rail corresponding to the slider is opened inside the base plate, and a control component is installed inside the side of the slide rail. A first cylinder is installed at the upper end of the slider. This invention, by setting up a feeding mechanism, combined with an infrared sensor and controller, achieves automatic clamping, precise feeding, and automatic positioning, replacing manual feeding, reducing labor intensity, improving feeding accuracy and heating uniformity, and increasing production efficiency.

The present application relates to the technical fields of bell-shaped shell medium-frequency heat treatment, in particular to a kind of drive shaft bell-shaped shell inner chamber medium-frequency heat treatment shield ring tool, including inductor, hollow shield ring and inductor support, the upper end of the inductor is fixedly connected with inverted L-shaped frame, one end of the inverted L-shaped frame is fixedly connected with assembly seat, the back side of the inductor support is equipped with installation notch, the inverted L-shaped frame is fixedly installed in the inboard of installation notch, the upper end of the hollow shield ring is fixedly connected with two studs symmetrically, the surface of the inductor support is equipped with two limit holes symmetrically, the hollow shield ring is fixed on the inductor support in the present application, the action of manually sleeving shield ring is saved when bell-shaped shell medium-frequency heat treatment is processed each time, it is favorable to avoid the risk of missing shield ring, and the consistency of shielding effect before and after can be maintained, so that the quality of bell-shaped shell medium-frequency heat treatment processing is more stable.

The application mainly relates to an earphone, which comprises a supporting assembly and a core module connected with the supporting assembly, the supporting assembly is used for supporting the core module to be worn to a wearing position, the core module comprises a core shell, a transducing device, a first vibration transmission sheet and a vibration panel, the transducing device is suspended in a containing cavity of the core shell through the first vibration transmission sheet, the vibration panel is connected with the support and is used for transmitting the mechanical vibration generated by the transducing device to a user, wherein the core module is arranged so that the frequency response curve of the vibration panel in a non-wearing state has no effective resonance valley in the frequency range of 400Hz to 2kHz, which is beneficial to improve the medium frequency loss of the earphone, thereby improving the acoustic performance of the earphone; wherein the effective resonance valley is defined as that the reference line segment parallel to the horizontal axis of the frequency response curve has two intersection points with the frequency response curve, the intensity corresponding to the reference line segment is equal to 6dB minus the peak resonance intensity of the effective resonance valley, and the difference between the frequencies corresponding to the two end points of the reference line segment is less than or equal to 4 octaves.

The utility model discloses a medium-frequency induction heating device, comprising a medium-frequency power supply which is an induction heating power supply based on high-speed DSP chip control; the output transformer is connected with the medium-frequency power supply; a cantilever crane; the heating device comprises an induction heating coil connected with the output transformer, and the induction heating coil is mounted on the cantilever crane; the far infrared temperature measurement system and the induction heating coil are integrally designed; and the industrial constant-temperature water cooler is respectively connected with the output transformer, the medium-frequency power supply and the induction heating coil. The preheating device changes the preheating mode of top bending in a steel rail factory, the whole process is automatically controlled, the possibility of uncontrollable factors existing in manual operation is eliminated, it is ensured that the temperature meets the process requirement, heating is safe, efficient and uniform, steel rail breaking is avoided, the rejection rate is reduced, and the preheating device has popularization value in the industry.