223 results about "Medium frequency" patented technology

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 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 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 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 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 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 invention provides an electronic device which comprises a frame, a first antenna unit and a second antenna unit, the first antenna unit comprises a first feed source, a first antenna radiator and a first switch tuning circuit, the first antenna radiator is arranged in a first area of a first side frame, and the second antenna radiator is arranged in a second area of a second side frame. The first antenna radiator is switched to support a first frequency band and a second frequency band which are located in a middle frequency band; the second antenna unit comprises a second feed source, a first radiation branch knot and a first parasitic branch knot, at least part of the first radiation branch knot is arranged in the first area and located on the side, away from the top frame of the frame, of the first antenna radiation body, and the first parasitic branch knot is located on the side, away from the first antenna radiation body, of the first radiation branch knot and located outside the first area; the first radiation branch knot and the first parasitic branch knot support a third frequency band and a fourth frequency band which are located at a high frequency band or an ultrahigh frequency band. The electronic equipment provided by the invention can improve the communication efficiency and optimize the antenna layout.

The invention discloses a novel non-Newtonian fluid driven fixed abrasive polishing disc, and relates to the technical field of optical element polishing. The fixed abrasive polishing disc comprises an eccentric adjusting frame, a metal back plate, a caliber adjusting ring, a non-Newtonian fluid layer, a rubber sleeve, a fixing ring and a fixed abrasive polishing pad. The metal back plate is matched with the eccentric adjusting frame through the connecting shaft to achieve the adjustable eccentric distance, the caliber adjusting ring can be replaced with different calibers to meet different requirements, the rubber sleeve is filled with the non-Newtonian fluid layer, the fixed abrasive polishing pad is fixed with cerium oxide abrasive, and the size of the fixed abrasive polishing pad is slightly larger than that of the rubber sleeve. The dynamic stiffness characteristic of the non-Newtonian fluid layer is utilized to realize effective correction of full-band errors; the rigidity and efficiency are improved through the fixed grinding material, and hydration reaction is avoided; and multi-structure collaborative optimization of pressure transmission and fringe effect ensures process stability. Experiments show that the fixed abrasive polishing disk can reduce the intermediate frequency error of a fused quartz workpiece to 0.1 mu m and the Ra value to 1.6 nm, is suitable for diversified machining scenes and is high in practicability.

The invention provides an aspheric optical element partition processing path generation method based on an improved Lloyd algorithm, and belongs to the field of aspheric optical element processing.The aspheric optical element partition processing path generation method comprises the steps that firstly, on the basis of surface shape error data of an aspheric optical element, a processing area is divided into a high residual area, a low residual area and a non-processing area through self-adaptive double threshold and adjacent connectivity analysis; and combining the isolated regions. An improved Lloyd algorithm is adopted, high-order iteration and low-order iteration are carried out in a high residual error region and a low residual error region respectively, and a Voronoi grid which is adaptive to the region shape and controllable in density is generated. A spiral path is designed in each Voronoi unit on the basis of the center of mass, and a spiral path based on the Voronoi shape is formed, so that sufficient machining is ensured. According to the method, sudden rotation angles and curvature sudden changes in the path can be effectively avoided, and the processing density can be adaptively adjusted according to the surface shape error, so that the intermediate-frequency error is effectively inhibited, and the surface shape processing quality and efficiency of the aspheric optical element are improved.

The invention provides a noise reduction method, device and equipment for a thermal management system, a storage medium and a vehicle. The method comprises the following steps: obtaining assembly operation parameters related to noise in the operation process of a fluid mechanical assembly in the thermal management system; the assembly operation parameters comprise pressure pulsation signals; determining a component noise parameter of the turbomachine component based on the component operating parameter; environment noise signals are collected, and environment noise parameters corresponding to the environment noise signals are determined according to the environment noise signals; generating a noise reduction signal according to the component noise parameter and the environment noise parameter; and noise generated by the fluid mechanical assembly is subjected to noise reduction processing based on the noise reduction signal. According to the embodiment of the invention, by considering the noise influence of the pressure pulsation signal on the fluid mechanical component, the component noise parameter is determined based on the component operation parameter containing the pressure pulsation signal, and then the noise reduction information is generated, so that active noise reduction of low and medium frequency noise generated by the fluid mechanical component of the thermal management system is realized.

The invention relates to a low and medium frequency acoustic measurement and correction method in a high temperature environment, which comprises the following steps of: performing a calibration experiment on an acoustic conduit measurement system under a normal temperature condition to obtain an amplitude correction curve; acoustic measurement is carried out in a high-temperature environment, an inlet end area of a sound conduit is heated to a target high-temperature state through a heating device, a sound source generator is kept to output an excitation signal which is the same as that of a calibration experiment, and sound pressure data of an inlet microphone and sound pressure data of an outlet microphone are synchronously collected; sound pressure data of the inlet microphone and the outlet microphone are converted into frequency domain spectrums through a fast Fourier transform aggregation method, 1 / 3 octave spectrum analysis is carried out, and uncorrected sound pressure levels of all frequency bands are obtained through calculation; and according to the amplitude correction curve, carrying out band-by-band correction on the uncorrected sound pressure level of each frequency band, and synthesizing the corrected sound pressure level of each frequency band into a full-frequency sound level to obtain a corrected high-temperature acoustic measurement result. Compared with the prior art, the accuracy of acoustic measurement of middle and low frequency bands is improved.

The utility model discloses an improved bell gold pendant which comprises an outer shell, a plurality of hollow open grooves are formed in the surface of the outer shell, a bell tongue ball is arranged in the outer shell, an inner cavity shell is arranged in the outer shell, and the bell tongue ball is located between the outer shell and the inner cavity shell. A bell tongue ball is arranged in the inner cavity shell, the bell tongue ball can collide with the inner cavity shell and the outer shell to generate sound when shaking, a plurality of openings are formed in the surface of the inner cavity shell, a solid ball is arranged in the inner cavity shell, and the solid ball can collide with the inner wall of the inner cavity shell to generate sound when shaking. According to the utility model, the bell tongue ball impacts the housing and the inner cavity housing at the same time to generate two independent sound waves, and the sound waves are diffused outwards through the hollowed-out slots to form a high-frequency (housing) and intermediate-frequency (inner cavity housing) superposed sound effect, so that the stereoscopic impression and layering sense of sound are remarkably improved.

The application discloses a modeling method and system of an acoustic cavity in whole vehicle NVH medium frequency analysis and a storage medium, and comprises the following steps: vehicle body structure screening, CAS data screening, acoustic cavity blocking, acoustic cavity modeling, acoustic cavity separation and connection, and acoustic cavity material attribute assignment. The acoustic cavity model established by the method is closer to the actual situation, can be used for early medium frequency NVH performance analysis, and the simulation result has high accuracy.

The invention belongs to the technical field of nondestructive testing, and relates to a phase group velocity matching frequency dispersion removal method. The method comprises the following steps: S1, exciting a signal in a propagation medium, collecting a propagation signal, removing a frequency spectrum of an excitation signal in the propagation signal, and carrying out normalization processing; s2, solving a nonlinear frequency-wave number spectrum; s3, performing linear mapping according to the propagation medium frequency dispersion curve to obtain a linear frequency-wave number corresponding relation; s4, setting equal-interval wave number vectors, and performing linear mapping from the nonlinear wave number spectrum to obtain a linear wave number spectrum; s5, converting the linear wave number spectrum into a new normalized frequency spectrum according to a wave number-frequency corresponding relation, and adding an excitation signal frequency spectrum component to obtain a frequency spectrum of a non-dispersion propagation signal; and S6, performing calculation to obtain a frequency-dispersion-free reconstructed time domain signal. According to the method, the wave packet of the target mode can be extracted and separated, the frequency dispersion signal is recovered to the non-frequency dispersion signal, the signal quality and accuracy are improved, and the method is suitable for scenes such as structure health of ultrasonic detection.

The utility model relates to the technical field of sound insulation plasterboards, in particular to a honeycomb sandwich structure of a low-density sound insulation plasterboard, which comprises an upper surface layer, a lower surface layer and a honeycomb core layer, the honeycomb core layer is clamped between the upper surface layer and the lower surface layer and is formed by arranging a plurality of continuous honeycomb units along the plane direction; a resonance dissipation assembly is arranged in each honeycomb unit; the resonance dissipation assembly comprises a closed shell, gradient filling media and an elastic connecting piece, a plurality of through holes are formed in the closed shell, the gradient filling media are arranged in the closed shell in a layered mode, and the elastic connecting piece is elastically connected with the closed shell and the honeycomb unit, so that the resonance dissipation assembly is elastically hung in the honeycomb unit. According to the utility model, the low and medium frequency sound insulation performance can be improved while the light weight is maintained.

The anti-seismic drawing equipment based on liquid buffering comprises a drawing device, a working chamber, a first buffering chamber and a second buffering chamber, the drawing device is arranged in the working chamber, the working chamber is suspended in a buffering solution of the first buffering chamber, and the first buffering chamber is arranged in the second buffering chamber in a vacuum state; the working chamber is suspended in a buffer solution, high-frequency and large-amplitude impact instantaneously generated in the drawing process can be efficiently absorbed by utilizing viscous damping and density characteristics of the liquid, and the anti-seismic effect is improved; meanwhile, the vacuum state of the second buffer chamber can effectively obstruct sound transmission, vibration transmission is reduced in cooperation with the nested structure, the defect that a traditional sound insulation cover cannot obstruct low and medium frequency noise is overcome, the influence of high-strength noise generated by drawing operation on the surrounding environment is greatly reduced, and the sound insulation effect is improved. And the stability and the environmental protection property of equipment operation can be improved while the test precision is ensured.

The application discloses a kind of based on reinforcement learning's adaptive planner parameter tuning method and device, method includes: at low frequency control frequency, in parameter adjustment network, according to the input environmental data, using reinforcement learning algorithm to adaptively adjust the parameters of local planner;At medium frequency control frequency, in local planner, according to the adjusted parameter, the planning trajectory of robot travel is generated and the feedforward speed is generated according to the planning trajectory;At high frequency control frequency, in controller, according to the feedforward speed and the feedback speed calculated by error compensator, generate final control instruction;Parameter adjustment network and controller are alternately trained and tested iteratively, and according to the test result, the parameters of local planner and the final control instruction generated by controller are continuously optimized.The application can improve system robustness and navigation efficiency, effectively reduce tracking error and enhance obstacle avoidance ability, can complete more accurate, efficient and reliable robot navigation task in complex environment.

The invention belongs to the technical field of satellite communication, and particularly discloses an integrated KaKu dual-frequency transceiver, which comprises an all-in-one machine main body, and is characterized in that the all-in-one machine main body is internally provided with an intermediate frequency selection network used for selecting and separating intermediate frequency signals with different frequencies; the KaKu dual-band BUC module is used for performing up-conversion on the intermediate-frequency signal and amplifying the intermediate-frequency signal into a radio-frequency signal of a Ka or Ku band; the KaKu dual-band LNB module is used for down-converting the radio frequency signal of the Ka or Ku band to an intermediate frequency; and the KaKu dual-band feed network is used for separating and synthesizing the radio frequency signals of the Ka or Ku band which are down-converted to the intermediate frequency. According to the invention, receiving and transmitting duplex of Ka and Ku dual-band signals in one device can be realized, and the problems of single-frequency work, complex device and heavy weight of a traditional terminal can be solved.

The invention relates to the field of building materials, in particular to a ceramic crystal sand sound-absorbing material for wall decoration and a preparation method of the ceramic crystal sand sound-absorbing material. The ceramic crystal sand sound-absorbing material comprises the following components in parts by weight: 40-60 parts of red mud, 20-30 parts of electrolytic manganese residues, 10-15 parts of borosilicate glass powder, 3-8 parts of a toughening agent, 5-10 parts of a pore-forming agent and 3-5 parts of an adhesive. The ceramic crystal sand sound-absorbing material is a material for wall decoration, has high mechanical strength to resist impact and abrasion, and can effectively meet the sound-absorbing requirements of low frequency, intermediate frequency and high frequency due to the unique hierarchical pore structure design, so that broad-spectrum sound absorption is realized.

The invention discloses a multi-dimensional prediction method and system for periodic weighting of a coal mine working face for edge calculation, which are applied to the field of coal mine down pressure early warning and aim at solving the problems that the false alarm rate of the existing weighting early warning is high, the early warning time delay is relatively high, and sufficient time cannot be provided for speed reduction of a coal mining machine, secondary pressure supplement of a hydraulic support, personnel evacuation and the like. According to the method, whether impact noise exists or not is judged by calculating the standard deviation of collected data, when the impact noise exists, online HP filtering processing is carried out on the collected data, LSTM reasoning is carried out on an intermediate frequency fluctuation item after filtering processing, and early warning is carried out based on a reasoning result and a long-term trend item after filtering processing.

The invention belongs to the technical field of sound systems, and discloses a sound guide device and sound amplification equipment. The sound guiding device comprises a shell and a sound dividing structure, the shell is provided with a sound inlet and a sound outlet, the sound inlet of the shell is used for directly facing a loudspeaker, the sound outlet of the shell is used for directly facing a sound playing port of multimedia equipment, and the sound inlet is communicated with the sound outlet through a sound guiding channel in the sound wave propagation direction; the sound dividing structure is arranged in the sound guiding channel and divides part of the sound guiding channel into at least two flow dividing channels in the first direction, and the first direction is perpendicular to the extending direction of the sound dividing structure. According to the sound guide device, the medium-high frequency energy loss of sound waves is greatly reduced, and the condition that the medium-frequency peak value is prominent can be effectively reduced by sound wave shunting, so that a flatter sound wave frequency response curve is obtained, and the sound output effect and the sound output quality of the sound amplification equipment are further improved.

The present application relates to a kind of heat treatment processes for improving H13 mandrel impact energy, comprising the following steps: after forging ultrafine treatment, medium frequency quenching, first tempering, second tempering, after forging heat treatment adopts ultrafine treatment process, eliminates reticular structure, obtains good spheroidizing structure, prepares good organizational condition for subsequent quenching and tempering, performance heat treatment adopts medium frequency quenching and tempering, because medium frequency induction coil heating is carried out by skin effect, heating speed is fast, grain is more fine, product heating and cooling stress is small, product straightness is good, using the heat treatment mode of after forging ultrafine treatment+medium frequency quenching and tempering can make the refining steel diameter≤φ200mm specification mandrel obtain higher strength and good impact energy, better solve the problem of low impact energy of H13 mandrel forgings below specification ≤φ200mm of vacuum refining steel production using conventional heat treatment process, meet product design and use requirement, under the premise of strength satisfying design requirement, room temperature average impact energy KV2≥20J.