27 results about "Frequency wave" patented technology

This invention relates to a method for extracting guided wavenumbers in variable thickness structures, belonging to the field of nondestructive testing technology. It utilizes an excitation signal to generate guided wave signals on the surface of the object under test. Based on a set window function and a set window length, the two-dimensional wavefield signal obtained by sampling the guided wave signal is divided into multiple local wavefield signals. A short-space Fourier transform is then performed on each local wavefield signal to obtain the amplitude-frequency-wavenumber array corresponding to each local space. A frequency range is then selected by summing the amplitude-frequency-wavenumber arrays of each local space, using the center frequency of the excitation signal as the midpoint. The weighted average wavenumber of each frequency point within the selected frequency range is calculated using the amplitude corresponding to the wavenumber sequence at each frequency point as the weight. The mean of the sum of the weighted average wavenumbers at each frequency point is then used as the wavenumber corresponding to the center position of each local signal space, and these values ​​are sequentially spliced ​​to obtain the wavenumber curve of the guided wave signal. This method solves the problem in existing technologies where the obtained guided wavenumbers cannot accurately reflect the thickness changes of variable thickness structures.

The application discloses a wave compensation system and method for umbilical cable deployment of engineering ships, and belongs to the technical field of umbilical cable tension control. The system comprises a winch mechanism, a cable arrangement mechanism, a compensation mechanism and a detection and control unit. The compensation mechanism adopts a double-layer parallelogram winding structure composed of four pulleys, and the path length of the umbilical cable is changed by driving the pulley frame to move through a linear composite oil cylinder. The system adopts a hybrid compensation strategy combining passive compensation and active compensation. The passive compensation utilizes the energy storage characteristics of the accumulator to achieve rapid response to high-frequency wave disturbance, and the active compensation realizes compensation accuracy correction through feedforward control and feedback control. The controller monitors the pulley displacement and controls the winch to wind or unwind the cable when the threshold is exceeded, thereby expanding the effective compensation range of the system. The cable arrangement mechanism and the winch are synchronized to ensure that the umbilical cable is uniformly arranged on the drum. The application realizes stable umbilical cable tension in complex sea conditions, and provides a more reasonable solution for underwater deployment.

This application relates to the field of wearable device technology, and more particularly to a wearable device. The wearable device body includes a housing, a screen assembly, a motherboard, a functional module, and an elastic wave receiving unit. At least one of the screen assembly and the housing is configured to deform under user operation to generate elastic waves. The elastic wave receiving unit is configured to receive the elastic waves and generate an elastic wave signal. The motherboard is configured to control the functional module to perform corresponding functions when the elastic wave signal matches a target elastic wave signal. The wearable device of this application, by utilizing the elastic wave receiving unit to achieve functional control of the wearable device, not only facilitates user operation but also, because elastic waves are low-frequency waves with high energy and long wavelengths, have strong anti-interference capabilities, thereby improving signal transmission reliability. Furthermore, it eliminates the need for additional openings in the wearable device, thus reducing the difficulty of waterproofing and effectively improving the waterproofness of the wearable device.

The application discloses a kind of high-temperature-resistant polymer-based electromagnetic shielding composite material and preparation method thereof, in-situ growth polypyrrole on the surface of magnetic metal powder, obtain composite filler with good magnetic performance and conductivity, then the obtained composite filler is introduced into polyimide matrix, and high-performance electromagnetic shielding material is obtained.The material obtained by the application has good electromagnetic shielding performance, and the electromagnetic shielding performance in L wave band can reach up to 39dB, and the shielding efficiency in X wave band can reach up to 35dB, and good electromagnetic shielding characteristics are exhibited in low-frequency wave band and high-frequency wave band.The lowest thermal decomposition temperature of the material obtained by the application is 500 DEG C, and it can be used in 350 DEG C environment for a long time, and it has important value in the field of polymer-based high-temperature-resistant electromagnetic shielding materials.

A cooking apparatus includes: a cooking chamber; a first heating source disposed above the cooking chamber; a second heating source disposed below the cooking chamber; and a shelf. The first heating source includes a plurality of heaters, and the second heating source includes a magnetron configured to generate high-frequency waves. The cooking chamber includes a first cooking area formed above the shelf and a second cooking area formed below the shelf. The first cooking area supports a first object to be cooked using the first and second heating sources. The second cooking area supports a second object to be cooked using the second heating source. The shelf includes a cooking surface and a heat generator. The heat generator is configured to generate heat due to the high-frequency waves and transfer the heat to the cooking surface.

This invention relates to the field of micro-motion surface wave exploration methods, and discloses an automatic extraction method for dispersion curves of micro-motion surface waves based on connected component analysis. The method includes cross-correlation extraction of virtual source surface wave shot gathers, frequency-wavenumber domain amplitude spectrum calculation, adaptive threshold binarization, connected component analysis, frequency-wavenumber domain surface wave mask generation, mask-amplitude matrix element multiplication, phase velocity picking, Hampel filtering, and automatic generation of dispersion curves. This invention utilizes image connected component analysis and other operations to process the amplitude spectrum of micro-motion surface waves, separating the surface wave signal region from the frequency-wavenumber domain amplitude spectrum image. It automatically identifies discrete phase velocity points from images containing only surface wave dispersion energy stripes and uses Hampel filtering to remove distortion points, ultimately achieving high-precision automated measurement of the dispersion curve.

This invention discloses a lightweight, broadband traveling wave suppression and absorption integrated structure in the field of absorbing materials technology. The structure includes a structural layer comprising a wave-transmitting layer, a traveling wave suppression layer, an absorption layer, and a reflection layer. The wave-transmitting layer is located on the upper surface of the structural layer, and the reflection layer is located on the lower surface. This invention improves high-frequency absorption performance through a multi-layered composite structure. First, the wave-transmitting layer prioritizes reducing surface reflection, ensuring efficient entry of high-frequency electromagnetic waves. The traveling wave suppression layer optimizes attenuation for high-frequency traveling wave modes. The absorption layer employs an alternating stacking configuration, extending the electromagnetic wave propagation path through multi-stage impedance matching and enhancing high-frequency energy dissipation. The reflection layer facilitates the re-entry of unabsorbed residual high-frequency waves into the loss region, overcoming the deficiency of reduced polarization loss at high frequencies and achieving stable absorption across a wide bandwidth.

The application provides a longitudinal and transverse wave separation water exploration method and system based on a reflection coefficient and a stress gradient, and the method comprises the following steps: collecting original seismic record data of a tunnel site and performing pretreatment; a longitudinal and transverse wave separation method is used to separate longitudinal waves and transverse waves from the pretreated seismic wave data; wherein, F-K filtering separates wave fields with different apparent velocities through frequency-wavenumber domain transformation, and realizes preliminary separation of longitudinal waves and transverse waves; for the overlapping part of the longitudinal waves and the transverse waves remaining in the F-K domain; linear Radon transformation is used to map the data from the time-space domain to the ray parameter domain, and further separate the wave fields with similar apparent velocities; a polarization filter is used to finally separate the longitudinal waves and the transverse waves by using the polarization characteristics; based on the separated longitudinal waves and the transverse waves, reflection coefficient imaging and stress gradient imaging are calculated respectively; and according to the reflection coefficient imaging result and the stress gradient imaging result, the underground water occurrence condition is identified. The identification precision of the underground water occurrence condition is improved.

This invention discloses a method and system for extracting vehicle signals based on distributed acoustic sensing, comprising: acquiring raw spatiotemporal vibration signals collected along a road by a distributed fiber optic acoustic sensing system; performing bandpass filtering on the raw spatiotemporal vibration signals to obtain a preliminary filtered signal; superimposing the preliminary filtered signals in the time dimension within a preset time window to obtain a signal-enhanced superimposed signal; normalizing the signal amplitude of each sensing channel in the superimposed signal to obtain a normalized vibration signal; transforming the normalized vibration signal to the frequency-wavenumber domain; and applying a hard threshold filter to the frequency-wavenumber domain signal to remove irregular noise to obtain a first filtered signal. The method and system of this application improve the accuracy and robustness of extracting vehicle signals from complex road noise backgrounds.

The present application relates to a kind of double air chamber OWC wave energy structure based on artificial island steel cylinder, belong to marine wave energy utilization technical field, structure includes adjacent steel cylinder and the wave energy unit embedded between them;Wave energy unit is provided with air chamber main body, air chamber main body is separated into first air chamber and second air chamber by partition wall sequentially arranged along the direction of wave propagation inside, first air chamber is located outside, and second air chamber is located inside;Second air chamber extends horizontally via one side of first air chamber, and is connected to water inlet.The structure integrates wave energy unit in the assembly space between adjacent steel cylinder, realize seamless integration with artificial island main body, save space and cost;Second air chamber effectively prolongs hydraulic path because flow channel is longer, inertia is greater, and stable response long-period wave.First air chamber is close to water inlet, response is fast, and short-period wave is efficiently captured.Double air chamber cooperates to realize the frequency utilization of wide frequency wave energy, significantly improve conversion efficiency and power generation stability.

This application relates to a seismic wavefield extension method, apparatus, device, storage medium, and computer program. The method includes: acquiring a seismic image at any time within a reference time period; performing image denoising on the seismic image to obtain a target seismic image; calculating the dispersion relation of the wave equation corresponding to the target seismic image according to a preset spatiotemporal finite difference method; performing a Fourier transform on the wave equation according to the dispersion relation to obtain the frequency-wavenumber domain seismic wavefield corresponding to the target seismic image; selecting the negative frequency component in the wavenumber domain seismic wavefield; and performing wavefield extension on the frequency-wavenumber domain seismic wavefield according to the negative frequency component to obtain the target seismic wavefield. This application improves the efficiency of seismic wavefield extension.

The application relates to the technical field of exploration and development, and discloses a high-frequency noise suppression method and device based on frequency-wavenumber, which comprises the following steps: obtaining seismic data of a target area to establish a standard frequency spectrum of the target area, identifying high-frequency noise of the target area, determining a wavenumber range of effective signals in a frequency-wavenumber domain, suppressing the high-frequency noise, obtaining a suppressed frequency spectrum, and obtaining seismic data after high-frequency noise suppression. In this process, whether the seismic data contains high-frequency noise is identified by establishing a standard frequency spectrum, the wavenumber range of effective signals in the frequency-wavenumber domain is determined, the interval range of the effective signals in the high-frequency band is circled, data outside the interval range is suppressed, the high-frequency effective signals are not suppressed in the high-frequency noise suppression process, the risk of effective signal damage is reduced, and the fidelity denoising processing is realized.

This invention provides a three-dimensional full-focusing ultrasound imaging method based on a frequency-wavenumber domain row-column addressable array, belonging to the field of three-dimensional full-focusing ultrasound. The method includes the following steps: using a row-column addressable array with a total of N+N transmitting elements to perform ultrasonic scanning on a medium to obtain acquired signals; based on the acquired signals, performing spatial sampling to obtain a three-dimensional voxel network; using a frequency-wavenumber domain method to beamform the radio frequency data corresponding to the three-dimensional voxel network; and performing envelope processing on the beamformed data to form a three-dimensional image. This invention's beamforming method for three-dimensional full-focusing ultrasound imaging based on a frequency-wavenumber domain row-column addressable array significantly reduces the number of elements and beamforming channels required for three-dimensional imaging by using a row-column addressable array, while providing a larger imaging area. The imaging process employs full-matrix capture to obtain high-resolution images, and the frequency-wavenumber domain beamforming method significantly shortens the imaging time.

This invention provides a steel-concrete floating platform with a roll reduction mechanism. The suspended main body includes a central column and multiple side columns. A wind turbine is installed on the top of the central column, and the bottom is anchored to the seabed via a mooring system. A central liquid storage tank is installed inside the central column, and multi-functional integrated compartments are installed in each side column. The central liquid storage tank and the multi-functional integrated compartments are connected by horizontal connecting pipes. When the platform is excited by high-frequency waves, the roll reduction system uses liquid to circulate back and forth between the central liquid storage tank and the multi-functional integrated compartments, generating reverse inertial force and damping force to suppress high-frequency vibration. When the platform is excited by low-frequency waves and tilts at a large angle, the liquid sloshing in the multi-functional integrated compartments generates a reverse overturning moment, and the energy is dissipated through an energy dissipation mechanism to suppress low-frequency rigid body motion. By adjusting the liquid level in the multi-functional integrated compartments, the platform's center of gravity is adjusted simultaneously, and the natural frequency of the roll reduction system is tuned, effectively covering the entire frequency band of wave loads.

The present application relates to a kind of active deviation weighted adjustment and frequency oscillation intensity driving parameter adaptive frequency control method for virtual synchronous generator, comprising: active deviation weighted adjustment based virtual synchronous generator frequency control;Based on the adaptive adjustment of virtual inertia and virtual damping to frequency oscillation intensity.The present application is by introducing the active power deviation adjustment link of weight coefficient α Net active acceleration power into rotor motion equation is equivalently adjusted, frequency excessive deviation caused by power imbalance is weakened as a whole, frequency variation process is more gentle under the premise of not increasing convergence time, and steady-state frequency difference under island can be reduced;At the same time, in the parameter adaptive adjustment, frequency oscillation intensity is introduced, improved disturbance stage division logic is proposed, and instantaneous frequency characteristic quantity and sliding time window statistics are used to adjust parameters in stages;The present application can suppress frequency fluctuation as a whole in the whole time domain, speed up the attenuation of frequency oscillation, further suppress the residual oscillation in adjacent disturbance gap, and realize the collaborative improvement of frequency peak suppression and vibration elimination.

The application provides a method, device, equipment and system for suppressing ground roll. The method comprises the following steps: performing frequency-wave number domain filtering preprocessing on original seismic data to obtain an initial suppression result; performing frequency band segmentation processing on the initial suppression result to obtain medium frequency band sub-data and low medium frequency band sub-data; obtaining a low medium frequency prediction signal according to the medium frequency band sub-data and a pre-trained unsupervised deep neural network model, wherein the pre-trained unsupervised deep neural network model is trained according to the medium frequency band sub-data and the low medium frequency band sub-data; performing difference calculation on the low medium frequency prediction signal and the low medium frequency band sub-data to determine ground roll noise to be processed; and subtracting the ground roll noise to be processed from the initial suppression result to complete the suppression processing of the ground roll, thereby solving the problem of ground roll residue and improving the suppression accuracy of the ground roll.

The application belongs to the field of polymer composite materials, and provides a low-frequency wave-absorbing / heat-conducting composite material and a preparation method thereof.The low-frequency wave-absorbing / heat-conducting composite material is prepared from CoNi fillers and polydimethylsiloxane; the CoNi fillers are prepared from cobalt salt and nickel salt under the conditions of a directing agent and a reducing agent; and the directing agent includes one or more of polyvinylpyrrolidone, cetyltrimethylammonium bromide and diethylenetriamine. The CoNi fillers are prepared by using one or more of polyvinylpyrrolidone, cetyltrimethylammoniun bromide and diethylenetriamine as a shape directing agent, so that the composite material has excellent heat conductivity and wave-absorbing performance; meanwhile, the composite material has high saturation magnetization, low coercivity and low-frequency wave-absorbing performance.

This invention discloses a wide-frequency-domain active resonant built-in point absorption wave power generation device and its control method, belonging to the field of wave power generation technology. The device includes an energy harvesting system, a PTO system, an active resonant control system, and an energy storage system. The energy harvesting system includes a cylindrical float. The active resonant control system includes a wireless data transceiver unit, a control unit, a pull-wire sensor, and a variable inertia mechanism. The wireless data transceiver unit is fixed to the top of the cylindrical float, the control unit is fixed to the upper part of the cylindrical float, and the pull-wire sensor is located between the upper and lower parts of the cylindrical float. This invention uses the above-mentioned device and method to track and match the changing wave frequency through active resonant control, achieving resonance. This maintains high energy conversion efficiency even in sea areas with wide-frequency wave variations, solving the problems of traditional point absorption devices that can only operate at a single resonant frequency and generating a large amount of reactive power by controlling the electromagnetic force of a motor to achieve resonance.

The application discloses a semi-submersible floating wind turbine foundation with moon pool structure, comprising a plurality of pontoons, the center of each pontoon is a hollow moon pool structure, the top of each pontoon is provided with a cover plate for closing the top of each moon pool structure and forming a closed air cabin above the moon pool; each pontoon is connected by a support structure to form a foundation platform. The application forms a closed air cabin above the moon pool, when the pontoon swings, the gas in one side of the air cabin is compressed to generate positive pressure, and the other side generates negative pressure to generate a restoring moment, so that the moon pool has its own characteristics, and the swing amplitude of the foundation platform is further reduced by the restoring moment. At the same time, by combining the vibration water column characteristics of the moon pool and the aerodynamic characteristics of the air cabin with the self structural dynamic characteristics of the semi-submersible wind turbine foundation, the suppression ability to low-frequency and high-frequency waves is enhanced, so that the widely applicable roll reduction effect is achieved, and the stability of the foundation platform is further improved.

The present application relates to the technical fields of wideband power amplifier, and especially relates to a wideband power amplifier input control circuit, which comprises: a first operational amplifier circuit, a same-phase input end of which is connected with a related voltage signal of a wideband power amplifier output signal, an opposite-phase input end of which is connected with a voltage signal corresponding to a preset voltage threshold for amplitude stabilization, and an output end of which outputs a voltage signal for amplitude stabilization; a waveband selection circuit, an input end of which is connected with a preset waveband selection control signal, selects and outputs a segmented preset voltage signal corresponding to a frequency waveband of the output signal; a second operational amplifier circuit, a same-phase input end of which is connected with the segmented preset voltage signal, an opposite-phase input end of which is connected with the voltage signal for amplitude stabilization, and an output end of which outputs an attenuation value control voltage signal; and an electrically tunable attenuator, an input end of which is connected with the attenuation value control voltage signal, and an output end of which outputs a working radio frequency signal to the wideband power amplifier. The present application can solve the technical problem of unstable power output amplitude of the wideband power amplifier.

The application discloses a radar target active stealth test system and test method based on active cancellation, and relates to the electromagnetic field and microwave technology field.The technical scheme points of the application are as follows: the test system and test method for reducing the target RCS by actively emitting electromagnetic wave signals to cancel the scattered echo by using the retransmission type amplitude modulation phase shift active cancellation circuit.The active stealth system based on active cancellation comprises a radar signal frame receiving antenna, a retransmission type active cancellation circuit module, a control system program and a cancellation parameter library, and a cancellation wave signal emitting antenna.The target RCS is reduced under the condition of a specific frequency after the vector synthesis of the scattered echo of the target and the cancellation wave signal generated by the cancellation antenna, and the active stealth effect is achieved.The test system of the application is suitable for the cancellation of various radar signal wave forms including continuous wave and step frequency wave, has high cancellation precision, and the hardware equipment and test method involved are simple and easy to realize.

The present application relates to a kind of superpower high frequency on-line ash removal device, it relates to industrial ash removal equipment field, the device includes installation cylinder, movable cylinder, waveguide, frequency wave resonance generator and loudspeaker extension tube, and the depth is adjusted by multistage air cylinder driving movable cylinder axial telescopic adjustment, motor drives rotating ring rotation adjustment circumferential position, air cylinder drives ball hinge swing adjustment angle, realize that loudspeaker extension tube is adjusted in any position and orientation in three-dimensional space, high frequency sound wave makes soot resonance drop, realizes on-line ash removal, the ash removal range of the present application is wide, positioning is accurate, strong adaptability, and it is applicable to the on-line ash removal operation of boiler, preheater, dust collector and other equipment.

The present application belongs to the technical field of seismic signal processing, and particularly relates to a method and system for suppressing single-frequency interference, obtaining a seismic shot gather to be processed; performing frequency-wavenumber domain transformation on the seismic shot gather to obtain a first frequency-wavenumber domain amplitude spectrum, and saving phase information of each time sampling point in the transformation process; performing 3*3 small-scale smoothing processing on the first frequency-wavenumber domain amplitude spectrum to improve the signal-to-noise ratio; performing Hough transformation on the smoothed amplitude spectrum to identify the stripe position corresponding to the single-frequency interference; performing energy zeroing processing on the stripe and the surrounding area of the first frequency-wavenumber domain amplitude spectrum according to the stripe position and a preset blank band length to obtain a second frequency-wavenumber domain amplitude spectrum.