384 results about "Frequency wave" patented technology

The invention provides a frequency converter dynamic fault diagnosis method and system based on a multi-brand load test platform. According to the method, multiple real-time operation parameter sets are acquired, the amplitude attenuation threshold and the frequency fluctuation interval of a voltage waveform fragment are dynamically adjusted according to a load mode configuration file, the dynamic voltage reference parameter corresponding to the current load mode is generated, and then the actual waveform and an expected current phase curve are compared frame by frame; the method comprises the following steps: firstly, calculating to obtain a phase offset, then constructing a multi-dimensional operation characteristic spectrum, then carrying out time sequence cross validation on a sudden change time node of a power factor jump trajectory and an abnormal waveform position in a harmonic distortion incidence matrix, outputting an abnormal mode code, and finally, matching a load adaptation grade constraint condition to generate a diagnosis report; according to the technical scheme provided by the invention, the fault diagnosis precision and the cross-brand system adaptation capability in a complex load scene are remarkably improved, and the problem of misjudgment of a single brand threshold rule in a multi-device scene is effectively solved.

The invention relates to a time-varying power high-precision calculation technology of an electric drive system under strong electromagnetic noise interference, and mainly solves the problem of inaccurate power calculation of the electric drive system under strong electromagnetic environment noise and frequency time-varying fluctuation scenes. According to the core technology, a dominant frequency fluctuation curve of a signal is obtained through dynamic tracking of a dominant frequency, and a dynamic band-pass filter changing along with the dominant frequency of the electric drive system is constructed; suppressing pulse noise by combining amplitude self-adaptive filtering of a nonlinear weighting function; a phase demodulation technology fusing zero crossing point correction and Hilbert transform is adopted to eliminate the phase interference problem caused by complex waveforms and weak noise signals; and finally, establishing a time-varying power physical model based on the sliding window. According to the technology, the power calculation accuracy of the electric driving system under the conditions of strong field environmental noise and continuous main frequency conversion is remarkably improved.

The invention relates to the technical field of pipeline detection, and provides a non-contact pipeline fluid flow velocity measurement method based on a frequency wavenumber domain spatial spectrogram, and the method comprises the steps: collecting a turbulence signal in a pipeline through a piezoelectric film sensor; carrying out snapshot number segmentation on the turbulence signal to obtain a plurality of segmented turbulence time domain signals; fourier transform and narrowband signal processing are carried out on the segmented turbulence time domain signals, and a spatial spectrum corresponding to each narrowband signal component is obtained; constructing a three-dimensional frequency-wave number domain spectrogram according to the spatial spectrum function; and according to the three-dimensional frequency-wavenumber domain spectrogram, calculating the flow velocity of the pipeline fluid. According to the method, a three-dimensional spectrogram characteristic space is constructed through conjoint analysis of the frequency and the wave number, the angle, distance and frequency characteristics of the turbulence signals are decoupled through spatial spectrum estimation methods such as the MUSIC algorithm, multipath interference and noise are effectively restrained, the flow speed of fluid in a pipeline can be accurately estimated, and limitation in a traditional method is overcome.

The invention discloses a broadband wave-absorbing material based on an MAX-phase metasurface structure and an impedance matching optimization method of the broadband wave-absorbing material. The wave-absorbing material comprises an MAX-phase ceramic substrate and periodic metasurface structures which are arranged on the surface of the MAX-phase ceramic substrate in an array mode and composed of conductive resonance units. The resonance units are isolated through gaps, an equivalent R1L1C1 series resonance circuit is formed in an electromagnetic field, and a base body is equivalent to a parallel resistor R2. By establishing an equivalent circuit model and optimizing parameters R1, L1, C1 and R2, impedance matching of the wave-absorbing material in a target frequency band can be regulated and controlled, so that the wave-absorbing material at least has an absorption peak of which the reflection loss is less than-10 dB. According to the optimization method, electromagnetic simulation and circuit simulation are combined, optimized circuit parameters are reversely mapped into structure geometric parameters, material preparation is guided, and accurate design and broadband absorption of the wave absorbing performance are achieved.

The invention discloses a low ionosphere intelligent inversion method based on VLF radio wave detection, and the method comprises the steps: collecting ground-based very-low-frequency wave amplitude data, defining a gated cycle unit network objective function as an optimized performance index, and employing a mean square error as the objective function; and carrying out dynamic position updating by adopting a whale optimization algorithm, setting a double-stop criterion, and stopping iterative training to obtain an optimal model when the maximum number of iterations or a verification error convergence threshold value is reached. The calculation result of the LWPC model is used as a training set, the GRU network is used as an objective function estimator from foundation very low frequency data to low ionosphere parameters, the inversion method can accurately approach a real model, and the algorithm performance is effective and feasible and is remarkably improved compared with an existing model.

The invention belongs to the technical field of comprehensive utilization of ocean renewable energy sources, and particularly relates to a pilot frequency coupling-based wind wave energy multi-degree-of-freedom broadband control method, which comprises the following steps of: performing frequency domain identification on wind wave environment characteristics, and constructing a wind wave pilot frequency energy coupling model; based on the motion response characteristics of the multi-degree-of-freedom floating platform, designing a pilot frequency energy regulation and conversion mechanism; a full-working-condition dynamic optimization control strategy is adopted, and cooperative operation and energy flow self-adaptive distribution of the wind energy conversion unit and the wave energy conversion unit are achieved. Aiming at the significant difference and relevance of wind energy and wave energy in frequency characteristics, time scale and spatial distribution, a pilot frequency wind wave coupling dynamic model is established, and broadband capture of low-frequency wind-induced and high-frequency wave-induced coupling energy is realized under complex sea conditions through multi-degree-of-freedom motion decoupling and state observation, so that the wind-induced and high-frequency wave-induced coupling energy is obtained. The energy utilization rate, the attitude stability and the structural safety of the system are effectively improved, and good robustness and engineering adaptability are achieved.

To ensure the power supply adjustment capability to respond appropriately on a node-by-node basis to frequency fluctuations on a node-by-node basis.SOLUTION: A power system adjustment power management system 100 includes a frequency fluctuation index calculation unit 102 that calculates a frequency fluctuation index that represents a frequency fluctuation within a predetermined time at a point connected to each generator in the power system in response to a fault disturbance, a frequency fluctuation index constraint determination unit 103 that compares the frequency fluctuation index of the power system with a threshold value and determines whether the frequency fluctuation index is within an appropriate range or not, and an output response amount increment calculation unit 104 that calculates a change sensitivity of the frequency fluctuation index to an output response amount when the frequency fluctuation index is not within the appropriate range, and calculates an increment in the output response amount at the point on the basis of the change sensitivity of the calculated frequency fluctuation index.SELECTED DRAWING: Figure 2

The invention provides a low-frequency improved antenna structure which comprises a substrate, an antenna circuit is arranged on the front face of the substrate, an antenna ground is arranged on the back face of the substrate, an antenna unit is arranged on the front face side of the first edge of the substrate, and a low-frequency lifting branch knot is arranged on the back face side of the second edge of the substrate. The first edge and the second edge are a group of opposite sides of the substrate; the feed point supporting foot of the antenna unit is connected with the feed point of the antenna circuit, and the grounding supporting foot of the antenna unit and the low-frequency lifting branch knot are both connected with the antenna ground. According to the low-frequency improved antenna structure, the low-frequency lifting branch knot is arranged on one side of the antenna ground of the other edge, opposite to the antenna unit, of the substrate to form low-frequency waves with new frequency, and the problems that the antenna unit is narrow in low-frequency bandwidth and low in efficiency when the size of the substrate is limited are solved.

The present invention relates to the technical field of seismic exploration. Provided are a three-component seismic data vector anti-aliasing interpolation reconstruction method and an apparatus. The method comprises: representing three-component seismic data in a time domain as pure quaternions for vector joint; transforming the pure quaternion data in a time-space domain to a frequency-space domain to obtain frequency-space domain data; transforming the frequency-space domain data into a frequency-wave number domain; in the frequency-wave number domain, using an inclination angle scanning strategy to construct a mask matrix; performing vector anti-aliasing interpolation reconstruction on the frequency-space domain data and the mask matrix, so as to obtain a frequency-space domain reconstruction result; and inversely transforming the frequency-space domain reconstruction result to the time-space domain to obtain a time domain three-component three-dimensional data anti-aliasing reconstruction result. The present invention can effectively solve the problem of vector anti-aliasing reconstruction for three-component seismic data that contain both irregular and regular missing traces, thus improving the accuracy of effective wave event identification.

The present invention relates to the field of stem cell technology. The present invention discloses a method for inducing stem cells to secrete specific factors, which includes stimulating stem cells with high-frequency waves, emitting sound waves of a specific frequency to stem cells, regulating stem cells in a hypoxic environment, culturing stem cells in a hypoxic environment, stimulating stem cells with oxidative stress, and subjecting stem cells to oxidative stimulation treatment. The present invention can significantly enhance the proliferation ability of stem cells, promote the secretion of multiple active factors, and improve cell function and adaptability. As a non-invasive physical method, high-frequency wave stimulation can activate internal cell signal pathways without introducing exogenous substances, significantly improving the proliferation ability and tissue repair potential of stem cells. Hypoxic environment regulation simulates the naturally existing microenvironmental conditions in the body, greatly promoting the secretion of active factors such as vascular endothelial growth factor, basic fibroblast growth factor, and brain-derived neurotrophic factor for tissue repair and immune regulation.

Employing methodologies and systems to detect damage initiation and growth inside a composite material (matrix cracking, delamination, fiber break, fiber pullout, etc.) wherein damage produces high-frequency acoustic emission (AE) waves that are transported to recording sensors along with relatively lower frequency waves representing the flexural deformation of the impacted composite structure.

The invention provides a TMD lockout control method for motion suppression of a semi-submersible platform, and the method comprises the steps: carrying out the frequency domain decomposition of a random wave predicted by a target sea condition, obtaining the energy distribution of each frequency component, obtaining the equivalent amplitude of each frequency component according to the energy distribution, considering the amplitude response of the platform under the action of waves of different frequencies, and achieving the motion suppression of the semi-submersible platform. The method comprises the following steps of: calculating a weight ratio of platform motion response caused by each frequency component under the action of random waves by integrating three types of information, namely amplitude, amplitude response and motion suppression effect, and finally carrying out weighted combination on the locking time corresponding to each frequency component according to the weight ratio, so as to obtain the motion suppression effect of the platform. And the optimal locking control time suitable for the current random wave is obtained. According to the method, a high-complexity non-causal control command does not need to be deduced, control parameters can be updated in real time according to short-term sea condition changes, pitching response of a platform is effectively reduced, and comprehensive optimization control over multi-frequency waves is achieved.

The invention discloses a hydrophone low-frequency sensitivity calibration method based on time domain scaling average processing, relates to the technical field of hydrophone low-frequency sensitivity calibration, and solves the problem of inaccurate direct sound wave amplitude measurement caused by boundary sound reflection superposition of an experimental pool and a measuring device in hydrophone calibration. Comprising the following steps: placing a light-reflecting and sound-transmitting thin film in a water body, and carrying out transducer and thin film laying and laser focusing; the underwater sound pressure value is reproduced based on a laser interference method; when reflection sound and direct sound superposition occurs in low-frequency measurement data, adjacent frequency points are selected to carry out multiple times of measurement. The arrival time of the direct sound is accurately measured by transmitting the high-frequency sound pulse, so that alignment of starting points of waveform data with different frequencies is realized; when low-frequency measurement is carried out, not only data of the inspected frequency is collected, but a narrow frequency band near the inspected frequency is selected, and multi-frequency-point data is sequentially collected and subjected to subsequent algorithm processing.

The present invention relates to a tip for a high-frequency skin care device, the tip comprising: a housing; a first substrate which is disposed inside the housing; at least one electrode which is disposed on the first substrate and applies high-frequency waves to the skin; a second substrate which is disposed opposite the first substrate inside the housing in order to supply power to the first substrate; and a connector which electrically connects the first substrate and the second substrate, wherein the connector has a length which is longer than the distance between the first substrate and the second substrate.

The invention discloses a synchronous control method for improving a multi-machine black-start frequency phase angle coupling effect, and aims to improve the black-start recovery capability. The system adopts a parallel recovery strategy, so that a plurality of black-start micro-sources are started at the same time, and synchronization is quickly realized. However, the requirement of parallel recovery on the precision of pre-synchronization is extremely high, and due to the fact that in the pre-synchronization process before parallel connection and brake connection, the frequency and the phase angle have a coupling relation, and the rapid change of the phase angle difference in phase angle control easily causes frequency overshoot. In order to solve the problem, the system introduces a linear active disturbance rejection control (LADRC) method on the basis of traditional phase angle control, fast adjustment is made when frequency fluctuation is caused by phase angle difference change by means of high interference resistance and dynamic response speed, and phase angle change becomes more stable and controllable through timely and stable control of frequency, so that the system is more stable and controllable. Therefore, the interference on the frequency is reversely reduced, and the weakening of the frequency phase angle coupling effect is realized. The design not only ensures the rapidity of black start, but also improves the stability and recovery capability of the system.

The invention discloses a magnetic suspension bearing displacement detection method and device, a magnetic suspension bearing system, a storage medium and a computer program product, an axial displacement detection area of a magnetic suspension bearing is provided with four displacement detection probes used for detecting axial displacement of a rotor, and the four probes are divided into two groups; the first group of two probes are installed along a first symmetrical direction, the second group of two probes are installed along a second symmetrical direction orthogonal to the first symmetrical direction, the design parameters of the same group of probes are consistent, and the design parameters of the different groups of probes are not consistent; the method comprises the following steps: carrying out mean value and difference operation on signals acquired by four probes to eliminate radial coupling interference; and filtering the signal subjected to mean value operation and differential operation by adopting same-frequency notch processing so as to filter radial coupling interference. According to the scheme, high-precision stable operation of magnetic suspension axial displacement is realized.

The invention discloses a shield segment support crack disease impact elastic wave detection method and device based on KNN-BiLSTM. The detection method specifically utilizes impact elastic wave equipment to test a shield segment support, collects the frequency, wave velocity, amplitude, frequency and curve change characteristics of Rayleigh waves propagated from the surface of a structure, and uses a network structure based on KNN-BidirectionalLSTM to carry out data processing on a multi-element elastic wave characteristic and lining disease characteristic mapping model. And obtaining the shield segment support crack depth and water permeability detection result at the detection position. According to the method, the accuracy of crack depth detection is remarkably improved, the over-fitting phenomenon is effectively relieved, the recognition accuracy and speed of the model are improved, meanwhile, the crack depth prediction result can be obtained, the crack water permeability type can be detected, and the method has important practical value and popularization significance.

The invention discloses a step frequency continuous wave ground penetrating radar imaging device and a rapid imaging method, and belongs to the technical field of microwave ground penetrating imaging. The vector network analyzer is adopted, the radio frequency power amplifier is carried, the ultra-wideband directional antenna is combined, signals of a step frequency continuous wave system are adopted, the frequency range is 700 MHz to 3 GHz, the bandwidth is large, meanwhile, the large transmitting power can be achieved, and meanwhile the requirements for the detection depth and the detection resolution are met; according to the method, direct wave interference is eliminated by adopting a singular value decomposition algorithm, then the effective signal strength is improved based on an automatic gain algorithm, and finally clutter interference is eliminated by adopting a block matching algorithm, so that the signal-to-noise ratio is improved; according to the method, an F-K migration imaging algorithm is developed, processed data are converted to a frequency wavenumber domain through Fourier transform, wavenumber domain data are filled before fast inverse Fourier transform, and the transverse space sampling rate and the imaging speed are increased.

The invention belongs to the technical field of frequency selective surface radomes, and particularly relates to a frequency selective surface-based low-frequency wave-transparent and high-frequency reflection device and a satellite radome, which sequentially comprise a first low-pass layer, a first dielectric isolation layer, a first band-stop layer, a second dielectric isolation layer and a second low-pass layer from top to bottom, the first low-pass layer and the second low-pass layer are the same in structure, and each of the first low-pass layer and the second low-pass layer comprises first metal patch patterns which are periodically arranged; each first metal patch pattern is composed of four square ring patterns and a cross-shaped pattern, and the four ends of the cross-shaped pattern are connected with the four square ring patterns respectively; and the first band stop layer comprises second metal patch patterns which are periodically arranged. The novel low-pass layer / band-stop layer pattern multilayer structure is constructed, the effects of ultra-wideband low-frequency wave transmission and high-frequency reflection are achieved under the condition that the thickness is sacrificed, the problem that in-band ultra-wideband wave transmission and out-of-band ultra-wideband reflection are difficult to give consideration to in-band ultra-wideband wave transmission and out-of-band ultra-wideband reflection at the same time in existing frequency selection is effectively solved, and then normal work of a satellite antenna housing is guaranteed.

The invention provides hot-melt wave-absorbing resin, a low-frequency wave-absorbing prepreg and application of the hot-melt wave-absorbing resin and the low-frequency wave-absorbing prepreg in a low-broadband magnetic wave-absorbing composite material. The hot-melt wave-absorbing resin is prepared from the following raw materials: hot-melt resin and a composite absorbent, the composition comprises a combination of a coupling agent modified conductive absorbent and a magnetic absorbent. The raw materials of the low-frequency wave-absorbing prepreg comprise the hot-melt wave-absorbing resin and reinforced fibers with low dielectric constant and low gram weight. The hot-melt wave-absorbing resin provided by the invention realizes the low-frequency wave-absorbing performance covering 1GHz. Through the synergistic effect of the conductive absorbent and the magnetic absorbent, the broadband wave-absorbing prepreg covering low frequency is prepared by using a hot melting method, the dielectric loss of the wave-absorbing prepreg is improved, and the low-frequency wave-absorbing performance is enhanced. And the formula can be changed according to frequency band requirements to meet the wave absorbing requirements of different frequency bands (from 0.3 GHz to 18GHz). According to the low-broadband magnetic wave-absorbing composite material with the wave-absorbing honeycomb provided by the invention, the wave-absorbing bandwidth coverage is expanded by 1-18 GHz.

This paper provides a high-resolution frequency-wavenumber method capable of modal separation. Based on the frequency, wavenumber, and phase velocity characteristics of multimodal Rayleigh surface waves, a method for enhancing high-modal energy by weighting the F-K spectrum with a two-dimensional Gaussian window is proposed. This algorithmic approach enhances high-modal Rayleigh wave information, resulting in simple computation and clear physical meaning. Using probability distribution statistics, a frequency-phase velocity probability distribution is plotted. All extreme points are statistically analyzed, and the median of their phase velocity intervals is taken as the phase velocity of the frequency point in that mode. This more accurately separates and extracts multimodal dispersion curves.

The invention provides an L-band wave-absorbing material and a preparation method thereof, the wave-absorbing material comprises a Fe-Si-Al composite material, and the composite material is Fe-Si-Al soft magnetic particles with oxide layers formed on the surfaces; wherein the content of each element in the raw materials of the Fe-Si-Al soft magnetic particles is as follows: 84.5 to 85.5 weight percent of Fe, 9.5 to 10 weight percent of Si and 5 to 5.5 weight percent of Al; the diameter-thickness ratio of the Fe-Si-Al soft magnetic particle raw material is 50-100, and the average diameter of the Fe-Si-Al soft magnetic particle raw material is 20-40 [mu] m; and the thickness of the oxide layer is 5-12 nm. The wave-absorbing material disclosed by the invention has excellent low-frequency wave-absorbing performance and has the characteristics of being thin, light, wide and strong; the impedance matching Z of the wave-absorbing material is larger than or equal to 4, the minimum reflectivity of a product with the thickness being 5 mm is smaller than-10 dB within 1-2 GHz, and the wave-absorbing material can be suitable for being used under multiple wavelengths of the L wave band and meets the use requirement of the wave-absorbing material.

The invention discloses a seismic wave impedance high-resolution inversion method and device based on physical model constraint, equipment and a storage medium. The method comprises the following steps: training a forward modeling network by using logging wave impedance data and corresponding seismic data; performing well logging constraint-based training on the inversion network by using the well logging data, the initial low-frequency wave impedance data and the seismic trace position text data; training the inversion network based on the cyclic consistency constraint by using the unlabeled data under the constraint of the forward modeling network; utilizing an inversion network to obtain wave impedance data and a reflection coefficient of initial prediction; and performing iterative training on the inversion network, training the inversion network by using logging constraint and loop consistency constraint in each round of iteration, using an inversion result of the previous round of iteration as input, and outputting a final inversion result when an iteration termination condition is satisfied. The forward modeling physical model and the inversion network model are combined to form a closed-loop network, label-free data are fully utilized, and the physical interpretability of an inversion result is improved.

The invention discloses a deep strike-slip fracture fracture zone identification method, and the method comprises the steps: converting original seismic data into a frequency-wavenumber domain through Fourier transform, carrying out the multi-scale decomposition and downsampling through a radial filter cascade architecture, converting the data into a time-space domain through a directional basis filter, and carrying out the filtering. And acquiring an optimal direction by adopting an optimization strategy, and constructing characterization attributes based on neighborhood attribute differences to extract multi-scale fracture attributes. And introducing a plurality of level set functions to construct an energy functional model, and solving through a dynamic weight adjustment algorithm to realize internal and external band identification. And constructing a model by means of a topological relation based on distance-angle constraint to analyze the three-dimensional space topology. The problems that traditional data processing is not fine and model analysis is insufficient are solved, accurate recognition of the deep strike-slip fracture fracture zone is achieved, and the method has important application value in the fields of oil and gas exploration and development and the like.

The invention discloses a single-node water leakage position positioning method based on distance parameter inversion, and the method comprises the steps: firstly installing a noise sensor in an experiment pipeline, and repeatedly collecting signal data through changing the flow of fluid in the pipeline and simulating the position parameters of a leakage point from the noise sensor in a to-be-detected experiment pipeline operation state; decomposing and reconstructing a sound signal acquired by the sensor by using a self-adaptive variational mode decomposition method; analyzing the reconstructed collected sound data, constructing a low-frequency dispersion equation based on an elastic constitutive relation and a global matrix method, solving group velocity and phase velocity of modal waves in a low-frequency band range, namely waveguide invariants, and constructing a relation between a frequency wave number relation and a distance by utilizing the waveguide invariants; a distance parameter # imgabs0 # and a frequency dispersion parameter # imgabs1 # are introduced, frequency dispersion elimination transformation is established, the distance of a leakage point is calculated, and the defect that the detection range is small due to the fact that medium-high frequency signals are collected in acoustic emission detection is overcome.

The invention provides a temperature-resistant radar infrared compatible stealth coating and a preparation method thereof. The problems that an existing radar infrared compatible stealth coating is insufficient in temperature resistance and poor in low-frequency wave absorbing performance are solved. The temperature-resistant radar and infrared compatible stealth coating sequentially comprises a bonding layer, a wave absorbing layer and an infrared stealth layer from bottom to top, the bonding layer is made of NiCrAlY or NiCoCrAlY, and the bonding layer is made of NiCoCrAlY; the material of the wave absorbing layer is 20 wt%-65 wt% of a ceramic matrix and 80 wt%-35 wt% of an absorbent; the chemical formula of the absorbent is Fe0. 7Al0. 3Ti (1-x) RxO3, in the formula, x is equal to 0.2-0.55, and R is Ni, Nb or Ta; the infrared stealth layer is a precious metal layer arranged in a periodic structure.

The invention relates to the technical field of crossing of geophysical exploration and artificial intelligence, and discloses a three-dimensional VSP data reconstruction method based on a three-dimensional blind sidewalk time frequency-space multi-domain interpolation network model, and the method comprises the steps: obtaining a to-be-reconstructed three-dimensional VSP data volume containing an irregular missing sidewalk; inputting the three-dimensional VSP data volume into a trained three-dimensional space-time-frequency mixed domain convolutional network model; performing down-sampling on the input data through an encoder to extract initial spatial-temporal characteristics; inputting the initial spatiotemporal features into a residual spatiotemporal-frequency wavenumber domain joint convolution feature fusion module to obtain fusion features; and inputting the fusion features into a decoder, and reconstructing a complete three-dimensional VSP data volume through up-sampling operation. According to the invention, through joint learning of ground seismic data (providing a macrostructure) and illuminance data (providing a physical propagation path), a reconstruction result with a reasonable geologic structure and extremely high fidelity of wave field features can be generated.

The invention discloses an active power filter control method and system suitable for frequency fluctuation, and the method employs an FIR filter based on a Lagrange interpolation method to correct the decimal part of the sampling times, and employs a variable bandwidth adjustment internal model control (VBAI) technology to improve the bandwidth after frequency fluctuation. The problem that the control effect is seriously reduced due to the fact that traditional repeated control sampling times change caused by power grid frequency fluctuation is effectively solved, and control gain stability under frequency fluctuation is guaranteed.

The invention provides a method, device and equipment for exciting a single-mode guided wave in grounding flat steel, and belongs to the technical field of engineering structure detection, and the method comprises the steps: building a two-dimensional section model of the detected grounding flat steel through finite element analysis software, defining boundary conditions for the width and thickness in the two-dimensional section model, and carrying out the mode analysis and solving of the grounding flat steel. Performing statistics to obtain frequency-wave number data; based on frequency-wave number data, a phase velocity frequency dispersion curve and a group velocity frequency dispersion curve are drawn, after a corresponding mode is selected, excitation of specific single-mode guided waves is achieved in combination with a wave structure diagram and the application size and direction of a modulation load, and due to the fact that a two-dimensional section model including a width condition is obtained through finite element analysis, the excitation accuracy of the guided waves is improved. The phase velocity frequency dispersion curve and the group velocity frequency dispersion curve are recalculated, the corresponding wave structure diagram is combined, and the appropriate modal guided wave under the specific frequency is reselected for single excitation, so that the appropriate modal can be more accurately selected, and the defect detection accuracy is improved.

Enhanced growth, yield, chlorophyll, and nutrition value of plants is achieved by using a vector sum of high frequency impulse waves resulting from an intersection of fixed and variable frequency waves targeted below the soil. This results in an avalanche of waves with a broad range of frequencies travelling at very high velocities, thereby creating micro cracks and nano cracks in the roots. These high frequency impulse waves are created by a system comprising two microcontrollers and an energy source. Each of the microcontrollers comprises an oscillator, a buffer amplifier, a reset circuit, electrode terminals, and an IOT module. The first microcontroller also comprises a modulator and a feedback circuit. The high frequency waves reduce the water requirement of the plants, and their susceptibility to pest attack.