18 results about "Phase change" patented technology

The invention discloses a concrete internal defect quantitative detection method and system based on reflected waves, and belongs to the technical field of nondestructive testing. A reflected wave data matrix is obtained through multi-angle excitation and synchronous receiving; calculating energy characteristics of each channel, and constructing an energy response residual field; extracting waveform offset, spectrum jitter and phase change caused by defects by adopting a disturbance comparison algorithm to form a disturbance feature vector set; a defect-response function curved surface is further constructed, a defect topological structure is inversed based on gradient and curvature analysis, and defect geometric parameters are output; and finally, inputting the multi-moment defect parameters into the recurrent neural network, and predicting a defect evolution path and a failure risk. The method has high resolution and trend prediction capability, and is suitable for detection and early warning of concrete structures in bridges, tunnels and nuclear power projects.

The invention provides a multi-reflection superposition enhanced microwave displacement measurement method and system, and the method comprises the steps: S1, constructing a microwave multi-reflection propagation path, enabling a microwave radar to transmit electromagnetic waves to the microwave multi-reflection propagation path as a transmission signal, and receiving a corresponding echo signal; s2, extracting length change information of a microwave multi-reflection propagation path according to the echo signal; s3, establishing a linear superposition relation model between the total length of the microwave propagation path and respective displacements of W reflection surfaces in the microwave multi-reflection propagation path; w2; and S4, based on the linear superposition relation model, displacement information of the corresponding reflection surface is obtained and output. According to the invention, a larger phase variation can be obtained under the condition of small displacement or weak vibration, so that the measurement sensitivity is improved and the signal-to-noise ratio is improved.

The invention provides a 2D-MUSIC beam line damage positioning method and system, and relates to the technical field of material safety monitoring. By collecting reference guided wave signals at different temperatures, amplitude-phase changes of direct waves of all sensor channels are analyzed, and a temperature-induced amplitude-phase error matrix is constructed; the error matrix is introduced into a two-dimensional multiple signal classification (2D-MUSIC) algorithm, an ideal steering vector is corrected, and a spatial spectrum under an actual propagation model is reconstructed; a cost function is established in combination with noise subspace characteristics, and high-precision and high-robustness positioning of tiny damage is realized through iterative optimization and synchronous inversion of damage positions and channel error parameters. According to the method, the applicability and the positioning accuracy of the 2D-MUSIC algorithm in a variable-temperature environment are remarkably improved.

The invention provides a phase change blasting excitation seismic wave reflection method, a medium, equipment and a product, and relates to the technical field of tunnel engineering, the method comprises the following steps: arranging a detection hole and a plurality of blasting holes in a tunnel face, placing blasting tubes in the blasting holes, placing detectors in the detection hole, and generating seismic waves through phase change blasting; carrying out longitudinal wave and transverse wave separation on seismic wave signals detected by a detector, processing longitudinal waves and transverse waves by adopting a two-dimensional F-K digital filtering method, filtering interference waves, separating effective waves and direct waves, and dividing a data set of the effective waves into a training set and a test set; building a prediction model of the unfavorable geological disaster body in front of the tunnel face based on a support vector machine, and obtaining optimal parameters of the model by using a particle swarm algorithm; and training and testing the model by using the training set and the test set, and applying the tested model to tunnel geological forecast. According to the method, the accuracy of advanced geological forecast of the gas tunnel is improved, and the gas explosion risk is reduced.

A sensing system (50) that can image a phase change medium comprises: a transmission device (10) that generates a radar signal, generates a code, generates a carrier signal, generates a high-frequency signal by using the carrier signal and a multiplication signal obtained by multiplying the radar signal by the code, and transmits the high-frequency signal from a plurality of transmission antenna elements (18); a reflection plate (22); and a reception device (30) that receives, by a plurality of reception antenna elements (32), a high-frequency signal that is a reflected wave reflected by the reflection plate (22) or a measurement target (21) that is a phase change medium, or a scattered wave scattered by the same, converts the high-frequency signal into a baseband or intermediate-frequency reception signal, generates transmission path information from the reception signal by using the radar signal, the carrier signal, and the code, identifies the position of the measurement target (21) by using the transmission path information, corrects the focal point of the measurement target (21), determines the phase change of the measurement target (21), and generates an image of the measurement target (21).

This application provides a long-wave infrared light absorber based on phase change materials and MIM structures, belonging to the field of integrated photonic devices. The absorber includes a reflective layer, a double dielectric layer, and a metasurface layer. The metasurface layer allows light waves to enter the double dielectric layer through diffraction. The reflective layer and the metasurface layer form two reflective surfaces, allowing the light waves to undergo multiple reflections and achieve FP-cavity resonance. When the metasurface layer is crystalline and the polarization state of the light wave is not parallel to that of the metasurface layer, both the reflective layer and the metasurface layer possess metallic properties, enabling plasmon resonance when the frequency of the incident light wave matches the collective oscillation frequency of free electrons in the metal. Both FP-cavity resonance and plasmon resonance lead to the localization and enhancement of the electromagnetic field within the double dielectric layer, thereby enhancing the absorption of light waves. This application achieves reversible switching between two light wave absorption states by changing the phase state of the phase change material.

Provided is an electromagnetic wave control plate capable of emitting a beam in a predetermined direction θ0 on the basis of an incoming electromagnetic wave, the electromagnetic wave control plate comprising a plurality of unit structures arranged so as to impart a gradient of phase change amount along a first direction. A phase change amount Ψn of the n-th (n is an integer) unit structure in the first direction is set in a region between a first line represented by formula (1) and a second line represented by formula (2) in a two-dimensional coordinate system in which the horizontal axis represents the positions of the unit structures in the first direction and the vertical axis represents the phase change amount.　(1) KynsinθA, (2) kynsinθB, where k is the wavenumber of the electromagnetic wave.　yn is the coordinate of the unit structure in the first direction.　θA < θ0 < θB.

A device is prepared having a layered structure including a layer of phase change material and a layer of matrix material having embedded quantum emitters. An electric field is applied through the layer of matrix material and the layer of phase change material to change the emission wavelength of the quantum emitters. The phase of the phase change material is non-volatilely changed in each of one or more localized regions of the phase change material to form localized changes opposing those of each of the quantum emitters in the layer of matrix material, locally changing the electric field at each quantum emitter.

The invention discloses a multipath effect suppression method based on sequential statistics and a reflective maximum likelihood method, and aims to solve the problems that in the prior art, because a target is in a low-altitude flight state, generated multipath waves are reflected by the ground and the sea surface and enter a radar main lobe together with direct waves, coherent superposition is caused, amplitude and phase change is violently generated, and the radar main lobe is influenced. In order to solve the problem of low accuracy of angle estimation due to the fact that K large values are subjected to non-coherent accumulation, the method effectively utilizes the increased part of the amplitude in the multipath effect, avoids the dramatic change of the amplitude and the phase, and can enhance the detection probability by using the multipath effect. Meanwhile, according to the angle measurement method based on the reflection type maximum likelihood method, the angle of the multi-path wave is represented by the direct wave, coherent superposition is avoided, and the angle estimation accuracy is greatly improved.

The invention provides a sound wave regulation and control method and device, a terminal and a storage medium. The method comprises the following steps: constructing a waveguide array; the multi-frequency acoustic metamaterial device comprises a plurality of waveguides formed by acoustic metamaterial devices, the waveguide structure is formed by arranging a slowly-changing centrosymmetric rotatable structure, and the acoustic metamaterial devices can keep the transmissivity not smaller than a preset transmissivity threshold value under multiple frequencies and continuously regulate and control the transmission phase. According to the slowly-changing centrosymmetric rotatable structure, the area of the rotatable structure is increased to a preset area threshold value in an exponential mode and then decreased in an exponential mode; calculating transmission phase gradient distribution required by the waveguide array in the direction perpendicular to the incident wave according to the required wave control function; and determining a rotation angle required by the rotatable structure in the waveguide array according to the distribution, and rotating to the angle to realize a wave control function. By rotating the angle of the rotatable structure in the waveguide, the phase change within the range of 0-2 pi can be covered, and the transmission phase is continuously adjustable. Therefore, the required wave control function can be realized only by rotating the angle of the rotatable structure.

This application provides a calibration method, apparatus, storage medium, and calibration device for radar angle measurement. The radar includes a radar body and a cover. The radar body includes a receiving antenna. The calibration method includes: acquiring a first phase change, which is determined based on the distance between different receiving antennas; acquiring a second phase change, which includes the phase change caused by the radar body's influence on the reflected wave and the phase change caused by the cover's influence on the reflected wave; calculating the sum of the first and second phase changes to obtain a phase calibration value in the echo direction; and calibrating the phases to be calibrated measured in multiple echo directions based on the phase calibration value to obtain multiple calibration data. This application solves the problem that traditional radar angle measurement calibration methods do not consider the influence of the radar cover on the angle measurement accuracy by calibrating the radar body and the cover as a whole.

The invention relates to a method for measuring the gas-liquid ratio of a fluid inclusion, which comprises the following steps: sample preparation: cutting a rock sample into temperature measuring sheets, polishing, and positioning a target fluid inclusion; sound tweezers are locked, wherein a standing wave sound field is generated by combining high-frequency sound waves with a piezoelectric transducer array and a holographic acoustic lens or phased array technology, and bubbles in the inclusion are locked; raman spectrum verification: before and after the acoustic tweezers are locked, scanning the inclusion by adopting a Raman spectrum technology, and verifying that the sound field operation does not cause phase change or component loss by comparing peak position offset; performing Raman three-dimensional CT scanning and deformation correction: performing layer-by-layer scanning on the inclusion by utilizing a Raman microscope, constructing three-dimensional component distribution information of the inclusion, analyzing and simulating the influence of sound radiation pressure on the bubble form through a finite element, establishing a relation model of bubble deformation and sound field intensity, and correcting an initial volume calculation result; and gas-liquid ratio calculation: calculating a gas phase volume, a liquid phase volume and a sub-mineral volume in combination with the corrected three-dimensional model.

The application discloses a control method and system of an automatic dispensing machine, and relates to the technical field of automatic control, which comprises the following steps: collecting the dielectric loss factor and temperature change rate of glue and preprocessing; calculating the dynamic viscosity, shear temperature rise and phase change rate of the glue by a time-frequency joint analysis method to generate a phase change parameter matrix; inputting the phase change parameter matrix into a soliton dynamics model to obtain a soliton waveform of the glue under the nonlinear action and dissipation effect, optimizing the soliton waveform in combination with real-time viscosity to generate pulse parameters and dispersion compensation coefficients, and forming a soliton driving instruction set; loading the soliton driving instruction set to an FPGA controller of an electric valve to generate a high-voltage pulse waveform and execute high-precision dispensing, and monitoring the jet waveform and performing dynamic calibration; and the application optimizes the waveform by the soliton dynamics model and the step-by-step Fourier method, and realizes the accurate balance of the dissipation effect and nonlinear action of the glue.

The application discloses a quantitative detection method and system for internal defects of concrete based on reflected waves, and belongs to the technical field of nondestructive testing. A reflected wave data matrix is obtained through multi-angle excitation and synchronous reception; energy features of each channel are calculated to construct an energy response residual field; a disturbance comparison algorithm is used to extract waveform offset, spectrum jitter and phase change caused by defects to form a disturbance feature vector set; a defect-response function surface is further constructed, and defect topological structures are inverted based on gradient and curvature analysis to output defect geometric parameters; finally, defect parameters at multiple time points are input into a recurrent neural network to predict defect evolution paths and failure risks; the application has high resolution and trend prediction capability, and is suitable for concrete structure detection and early warning in bridges, tunnels and nuclear power engineering.

Provided is a transmission directivity control apparatus comprising: a generator that generates a light wave in which Nh continuous waves of light from a continuous wave of light having a frequency of f1 to a continuous wave of light having a frequency of fN_h are wavelength-multiplexed with the phases thereof synchronized; a first optical splitter that splits the output of the generator into two directions; a frequency converter that shifts the frequency of the light wave which has been split in one of the two directions, to a prescribed direction by a prescribed frequency of fRF; a first optical circuit that provides the light wave which has been split in a second direction of the two directions with a phase change depending on the frequency; a modulator that modulates the light wave which has propagated through the first optical circuit; an optical coupler that is for obtaining a resultant wave from the output of the frequency converter and the output of the modulator; a first frequency divider that is for obtaining, from the output of the optical coupler, for each p, a p-th paired wave, which is a resultant wave from a modulated wave having a center frequency of fp included in the output of the modulator and a continuous wave having a frequency shifted by fRF from the frequency fp; a p-th photodiode that receives the p-th paired wave; and a p-th antenna element that is excited by the output of the p-th photodiode.

The invention relates to the technical field of terahertz metamaterial devices, in particular to a terahertz absorption device based on vanadium dioxide ultra-bandwidth. The invention aims to overcome the common defects of function solidification, narrow absorption band and insufficient regulation and control flexibility of the conventional metamaterial wave absorber. The invention provides a wave absorber formed by stacking a vanadium dioxide resonance layer, a Topas dielectric layer and a metal reflecting layer from top to bottom. Effective regulation and control of the conductivity can be realized by utilizing the insulator-metal reversible phase change characteristic of vanadium dioxide under temperature regulation and control. A simulation result shows that when vanadium dioxide is in a metal state, the wave absorber realizes ultra-bandwidth strong absorption of 6.45 Thz in a frequency range of 4.17-10.62 Thz, and the average absorption rate reaches 97.2%; when vanadium dioxide is changed to an insulation state, the absorptivity is as low as 1.3%. The terahertz wave absorbing material is simple in structure and easy to prepare, has excellent terahertz wave absorbing performance, and can be widely applied to the fields of invisible devices, thermal radiation, thermal detection and the like.

The invention belongs to the technical field of materials, and particularly relates to a phosphorus-based intelligent wave-absorbing agent based on temperature response and a method for regulating and controlling the wave-absorbing or wave-transmitting performance of the phosphorus-based intelligent wave-absorbing agent. The invention provides an application of tin phosphide (SnP) in preparation of a wave absorbing agent or a wave absorbing material. SnP is a SnP mixed phase, a SnP cubic phase or a SnP tetragonal phase. The method comprises the following steps: performing high-temperature induction on a SnP mixed phase or a SnP tetragonal phase to obtain a SnP cubic phase so as to realize conversion from wave absorption to wave transmission; and carrying out low-temperature induction on the SnP mixed phase or the SnP cubic phase to obtain a SnP tetragonal phase so as to realize conversion from wave transmission to wave absorption. By means of the reversible phase change of the SnP cubic phase and the tetragonal phase, the material can be reversibly switched between a wave absorbing state and a wave transmitting state in an in-situ and non-contact mode, the wave absorbing material is really endowed with dynamic, active and adjustable intelligent attributes, and the bottleneck that a traditional material is formed at a time and the performance is fixed all the time is broken through.

This invention discloses a reconfigurable silicon substrate polarizer based on phase change materials and its polarization filtering method. The polarizer includes an input waveguide, an output waveguide, and a three-waveguide directional coupling region connecting the two. The coupling region includes a central waveguide and side waveguides on both sides, with a width difference between them to form a waveguide width perturbation. A phase change material layer is loaded on top of the central waveguide or the side waveguides. This invention utilizes the waveguide width perturbation and the refractive index change during the reversible conversion of the phase change material. When the phase change material converts to a crystalline state, it guides non-target polarized light signals into the phase change material region for absorption, allowing the target polarized light signal to be output with low loss through a path without phase change material. This invention achieves spatial decoupling between the optical field transmission path and the high-loss region, breaking the constraint between extinction ratio and insertion loss at the physical level, and possesses advantages such as non-volatility, zero static power consumption, and ultra-compact size.