Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

320 results about "Echo time" patented technology

Medical refrigerator body manufacturing detection system and method

The invention relates to the technical field of quality detection, in particular to a medical refrigerator body manufacturing detection system and method, and the system comprises a coating reflection detection module, a sound wave response measurement module, an optical signal fluctuation analysis module, a surface defect recognition module and a structural feature state evaluation module. According to the method, the reflection amplitude gradient change of the adjacent scanning areas is compared with the spectral curve continuity, so that the sensing precision of the surface reflection distribution continuity is improved, the recognition capability of weak anomalies is enhanced, and the internal potential defects are accurately captured in combination with the sound wave echo time and structural stability analysis of a specific part; a light intensity gradient model is constructed according to a sound wave analysis result, a splicing seam and a light intensity jump area of a sunken area are identified, abnormal forms such as scratches and bubbles are further extracted, coordinates are marked, the whole process depends on dynamic feedback and multi-signal linkage calibration, the identification precision and the coverage rate are improved, and medical box body quality global efficient detection is achieved.
Owner:HONGTAI ELECTRIC APPLIANCES LAIZHOU CITY

Magnetic resonance imaging method and device and storage medium

The invention relates to a magnetic resonance imaging method and device and a storage medium, and the method comprises the steps: scanning a target region through employing a first magnetic resonance sequence, setting a plurality of echo times, and collecting a plurality of spin echo images; recording a plurality of echo times and corresponding dispersion sensitivity coefficients according to the first magnetic resonance sequence; scanning the target area by using the second magnetic resonance sequence to obtain an apparent dispersion coefficient; and according to the plurality of spin echo images, the plurality of echo times, the dispersion sensitivity coefficient and the apparent dispersion coefficient, fitting to obtain a transverse relaxation time constant quantitative image for correcting the dispersion influence. According to the method and the device, the problem of dispersion when a magnetic resonance transverse relaxation time constant quantitative image is obtained through a variable echo time spin echo method in the prior art is solved, and the beneficial effect of effectively improving the quantitative accuracy is achieved.
Owner:WUHAN UNITED IMAGING LIFE SCIENCE INSTRUMENT CO LTD

Electromagnetic ultrasonic bolt stress detection system based on space-time complementation algorithm

The invention provides an electromagnetic ultrasonic bolt stress detection system based on a space-time complementation algorithm, and the system comprises the steps: carrying out the multi-channel ultrasonic signal collection of a to-be-detected bolt, and obtaining a multi-channel echo signal group; performing time-varying attenuation compensation and adaptive entropy weight denoising on the multi-channel echo signal group to obtain a denoised echo signal group; extracting echo time-domain features from the de-noised echo signal group, performing segmented time-frequency feature extraction on the de-noised echo signal group based on a short-time sliding window to obtain echo time-frequency features, and fusing the echo time-domain features and the echo time-frequency features into ultrasonic time-frequency features; performing wave field reconstruction on the de-noised echo signal group to obtain a spatial ultrasonic energy diagram, and extracting ultrasonic spatial features of the spatial ultrasonic energy diagram based on a self-attention map convolutional network; performing correlation detection and space-time complementary modeling on the ultrasonic time-frequency features and the ultrasonic space features to obtain ultrasonic space-time joint features, and performing stress analysis on the ultrasonic space-time joint features to obtain bolt stress data.
Owner:OPENEXTECH HANGZHOU CO LTD

Underwater weak echo signal detection method and system for airborne ocean laser radar

The invention belongs to the technical field of marine surveying and mapping, and discloses an airborne marine laser radar underwater weak echo signal detection method and system. According to the method, a waveform rising edge is determined by constructing a standard deviation curve, a water surface echo moment is accurately extracted, and two water surface geometric elements of a water surface point and a refraction vector are calculated on the basis; constructing a time-space constrained waveform superposition model, taking the Euclidean distance between the two water surface geometric elements as a neighbor discrimination standard, and screening and superposing neighbor waveforms by using a K neighbor judgment method to obtain a superposed pseudo waveform with a high signal-to-noise ratio; and finally, an improved normalized saliency peak detection method is utilized to judge the underwater echo position step by step and obtain the final underwater echo moment. After the model constructed by the invention is used for processing, the underwater weak echo detection of the airborne ocean laser radar is effectively realized, the maximum sounding performance of the airborne ocean laser radar is improved, and an effective technical support and a solution are provided for sounding data processing and application.
Owner:SHANDONG UNIV OF SCI & TECH

Water level measuring method and system based on ultrasonic waves

The invention relates to the technical field of water level online measurement, and discloses a water level measurement method and system based on ultrasonic waves. According to the invention, a variable time-sharing amplification circuit with a dynamic range is adopted, and the amplification times of echoes with different distances are automatically changed, so that the amplitude of an echo signal is kept to be more than five times of that of noise, and the influence of the noise on the measurement precision is effectively avoided; the method comprises the following steps of: receiving an echo signal, carrying out digital shaping on the echo signal according to a standard echo waveform near an echo peak value, and taking time corresponding to a waveform vertex after shaping as echo time, so that the influence of the measurement accuracy of echo waveform distortion is eliminated through the technology; meanwhile, the method that optimization is carried out after continuous three times of measurement is adopted, and the accidental phenomena of no echo and measurement value jumping can be effectively eliminated.
Owner:HANGZHOU ANLAN DIGITAL SENSING TECHNOLOGY CO LTD

Internal detection method and device for service closed metal structure and electronic equipment

The invention provides an in-service closed metal structure internal detection method and device and electronic equipment, and relates to the technical field of ultrasonic detection. The method comprises the following steps: acquiring geometric parameters of a metal structure; wherein the geometric parameters comprise the wall thickness and the outer diameter of the metal structure; controlling the high-frequency ultrasonic probe to emit high-frequency ultrasonic waves and receive first echoes; determining echo time according to the geometric parameters, and judging whether the working condition inside the metal structure is liquid or not according to the echo time and the first echo amplitude; when the working condition in the metal structure is non-liquid, the first low-frequency ultrasonic probe is controlled to emit, and the second low-frequency ultrasonic probe is controlled to receive a second echo; determining the internal working condition of the metal structure according to the second echo and the discrimination line of each working condition; wherein the working conditions comprise air, ice and concrete. The internal working condition of the closed metal structure can be rapidly detected.
Owner:SHIJIAZHUANG TIEDAO UNIV

Current transformer oil level monitoring system based on ultrasonic echo detection

The invention discloses a current transformer oil level monitoring system based on ultrasonic echo detection, which relates to the technical field of electric power monitoring and comprises the following steps: acquiring original echo time sequence data; calculating the distance between the transmitting end and the top of the metal expander by combining the propagation velocity of the ultrasonic waves in the air; and when the oil level height value is lower than a set threshold value, an alarm signal is triggered. According to the invention, the problems of easy clamping stagnation, complex installation, large temperature drift and environmental interference and the like of the traditional float-type, pressure-type and window observation methods are effectively overcome, remote uploading and local acousto-optic prompt are supported, and intelligent inspection and fault pre-warning identification under unattended operation are realized; and the operation safety, the monitoring reliability and the operation and maintenance intelligent level of the oil-immersed current transformer are remarkably improved.
Owner:STATE GRID ANHUI ELECTRIC POWER CO LTD ELECTRIC POWER SCI RES INST

Magnetic resonance temperature measurement imaging method and application thereof

The invention provides a magnetic resonance temperature measurement imaging method. According to the method, based on proton resonance frequency temperature dependence, phase self-calibration echoes are added in a temperature measurement imaging sequence; the phase unwrapping of the spatial dimension is carried out on the phase image by using the prior art, and the phase unwrapping of the time dimension is carried out on the temperature measurement phase image by using the self-calibration phase image. According to the method provided by the invention, the problem of reference basis failure of magnetic resonance temperature measurement imaging can be solved, the temperature measurement precision is not lost, and additional temperature measurement tools and intraoperative waiting time are not increased. According to the method provided by the invention, the temperature measurement precision can be improved by prolonging the echo time TE. The method provided by the invention can be used for thermal ablation treatment guided by magnetic resonance.
Owner:EAST CHINA NORMAL UNIV

Circumferential synthetic aperture radar imaging method

The invention provides a circumferential synthetic aperture radar imaging method, which comprises the following steps: acquiring a transmitting signal and an echo signal of radar circular motion, and preprocessing the transmitting signal and the echo signal to obtain a preprocessed echo signal; a compressed sensing method is adopted to convert a signal estimation and recovery problem into a norm minimization problem for signal filtering, and a target echo signal is obtained; dividing a plurality of sub-apertures by adopting a back projection algorithm, carrying out gridding processing on an imaging region, and calculating echo time delays of points in a grid and each position of the radar; and performing signal compensation on a target echo signal according to the echo time delay, performing azimuth focusing through coherent superposition processing to generate a plurality of corresponding sub-images, and performing step-by-step non-coherent fusion on the plurality of sub-images to obtain a circumferential SAR image. According to the invention, a small amount of effective data can be fully utilized for high-quality imaging, and high-resolution image quality is maintained while the imaging speed and the processing efficiency are improved.
Owner:SOUTHWEST UNIV

Steel belt fault detection method for spindle conveying

The invention relates to the technical field of fault detection, in particular to a steel belt fault detection method for spindle conveying, and the method comprises the steps: collecting echo signals received after an ultrasonic probe transmits ultrasonic waves to a steel belt in an operation process; obtaining each return band; calculating the echo time difference of each echo band; acquiring a peak-to-peak delay coefficient of each echo band; calculating an echo consistency coefficient of each echo band; obtaining all first quartered return bands; acquiring a steel belt echo attenuation value of the echo signal; after wavelet decomposition is carried out on the echo signal, a defect noise estimated value of each wavelet coefficient is obtained; and further obtaining a self-adaptive wavelet threshold value of each wavelet coefficient, and carrying out fault detection on the spindle transportation steel belt. According to the invention, the fault detection precision of the ultrasonic transmission mode is improved.
Owner:SHANXI XINHUAN PRECISION MFG CO LTD

Existing bridge pile foundation detection method and device based on phase difference method

The invention relates to the technical field of bridge detection, in particular to an existing bridge pile foundation detection method and device based on a phase difference method, and the method comprises the following steps: obtaining a first signal and a second signal detected by two acceleration sensors which are vertically arranged at an interval after a pile foundation is knocked; finding out an effective extreme value in the first signal and the second signal; obtaining a periodic phase difference between the effective extreme value in the first signal and the nearest effective extreme value in the second signal; and according to the abnormal change of the periodic phase difference, determining echo time so as to determine a defect position or a pile length. The problem that signal feature recognition and defect distinguishing are limited due to asymmetry of excitation positions and existence of an upper structure in the prior art can be solved.
Owner:CHINA RAILWAY MAJOR BRIDGE ENG GRP CO LTD +1

Sonar target motion identification method based on low-frame-rate bright spot structure sequence

The invention discloses a sonar target motion identification method based on a low-frame-rate bright spot structure sequence. The sonar target motion identification method comprises the steps of 1, roughly intercepting a bright spot structure; 2, accumulating a bright spot structure, sonar platform information and tracking information; step 3, motion compensation of the sonar platform; 4, accurately intercepting a bright spot structure; and 5, searching the optimal radial speed. According to the method, target radial motion parameters are extracted by means of distance steep motion of a sonar target among multiple frames of echoes, and a speed estimation loss function based on bright spot structure global optimal estimation is innovatively designed for the problems that the time interval between adjacent echoes of a low-frame-rate sonar target is long and the bright spot structure fluctuates greatly. According to the method, the global similarity between input period bright spot structures is fully utilized, the distance steep motion measurement precision is improved, the radial speed of the sonar target can be given at the same time, and the motion identification precision and stability of the sonar target are improved.
Owner:THE 715TH RES INST OF CHINA SHIPBUILDING IND CORP

SAR noise frequency modulation saturation interference suppression method based on time-frequency characteristics

ActiveCN119959888AWave based measurement systemsTime domainHigher order harmonics
The invention discloses an SAR noise frequency modulation saturation interference suppression method based on time-frequency characteristics, and belongs to the technical field of radar signal processing, and the method comprises the steps: building an SAR echo model under the condition of NFM saturation interference, carrying out the short-time Fourier transform of the interfered SAR echo, carrying out the fundamental wave and high-order harmonic detection, carrying out the notch filtering in each STFT window, and carrying out the noise modulation saturation interference suppression. And converting back to an echo time domain, and finally obtaining SAR echo data after interference suppression. According to the method, NFM saturation interference can be effectively suppressed, the effectiveness of the proposed method is verified through semi-actual measurement data of Radarsat-1, and compared with a time domain cancellation method, the method has better saturation interference suppression capability.
Owner:NANJING UNIV OF SCI & TECH

Sea wave feature inversion method based on reverse echo measurement

The invention belongs to the field of ocean wave feature extraction, and particularly relates to a sea wave feature inversion method based on reverse echo measurement, which comprises the following steps of: acquiring an echo signal from a seabed to an ocean surface, and performing adaptive time window smoothing processing on the echo signal to obtain an echo signal; carrying out abnormal value identification and missing data filling on the smoothed data; removing abnormal values by adopting an improved Tukey method, and filling missing data by adopting a segmented cubic spline interpolation method; through high-pass filtering and detrending processing, sea wave echo signals with low-frequency trends removed are obtained; and selecting a proper time window to calculate the dispersion of echo time, establishing a mathematical relationship between the dispersion and the significant wave height through a regression algorithm, and substituting observation data into an equation to obtain an inversion result of the significant wave height. According to the method, the sea waves are subjected to feature inversion based on the reverse echo measurement technology, the precision of sea wave feature extraction is effectively improved, the field measurement cost is reduced, and the stable and low-cost sea wave measurement method is provided.
Owner:INST OF OCEANOLOGY - CHINESE ACAD OF SCI

Municipal bridge damage defect detection method and system

The invention relates to the field of bridge damage detection, in particular to a municipal bridge damage defect detection method and system. The method comprises the following steps: carrying out edge detection and connected domain extraction on an acquired bridge surface grey-scale map to obtain a plurality of edge pixel points and a plurality of connected domains, and calculating the regularity of a target area; constructing a gray scale run-length matrix of the target rectangle, and calculating the texture confusion degree of the target area according to the gray scale run-length matrix; carrying out weighted summation on the regularity and the texture confusion degree, carrying out normalization, and taking a normalization result as the initial abnormal degree of the bridge; ultrasonic pulses are transmitted to the target area to obtain echo time and echo intensity, the echo time and the echo intensity serve as correction factors to correct the initial anomaly degree of the bridge to obtain a bridge damage index, and defect detection is completed. According to the technical scheme, the bridge defect detection efficiency and accuracy can be improved.
Owner:GUANGDONG RONGJUN CONSTR ENG TESTING CORP LTD

Audio-based information hidden transmission method, audio decoding method and electronic equipment

The invention discloses an audio-based information hidden transmission method, an audio decoding method and electronic equipment, which are applied to the field of communication. The audio-based information hidden transmission method comprises the following steps: acquiring to-be-embedded original information; generating symbol information according to the original information; obtaining a time delay corresponding to each symbol in the symbol information, obtaining an original audio carrier, and sequentially embedding the time delay corresponding to each symbol into the original audio carrier to generate an echo frame; and combining the echo frame and the original audio carrier to obtain a target audio. The original information to be embedded is embedded into the original audio carrier in the form of echo time delay, so that the confidentiality and security of the communication process are improved, and even if the target audio is accidentally recorded by third-party recording equipment, the embedded original information can still be analyzed from the recorded audio so as to trace the leakage source.
Owner:HARBIN HYTERA TECH CORP

Natural gas leakage detection method and device, electronic equipment and storage medium

The embodiment of the invention provides a natural gas leakage detection method and device, electronic equipment and a storage medium. The natural gas leakage detection method comprises the steps that all leakage areas of natural gas in a station are recognized; directionally transmitting an ultrasonic detection signal to each leakage area, and calculating the position information of each leakage area according to the echo time of the ultrasonic detection signal in each direction; calculating the natural gas concentration of the corresponding leakage area according to the gas temperature and the gas molecular weight of each leakage area; and displaying the position information and the natural gas concentration of each leakage area in a detection map of the station. According to the embodiment of the invention, through automatic and remote monitoring technologies, the exposure time of personnel on site is reduced, the safety risk is remarkably reduced, and powerful support is provided for emergency rescue work through accurate monitoring and visualization means.
Owner:PIPECHINA SOUTH CHINA CO +1

Relaxation time determination method and device and magnetic resonance quantitative imaging method

PendingCN119125982AReduce the impact of calculation accuracyimprove accuracyMeasurements using NMR imaging systemsMri imageMR - Magnetic resonance
The invention relates to a relaxation time determination method and device and a magnetic resonance quantitative imaging method. The method comprises the steps that preset echo time is acquired to generate a magnetic resonance image, the magnetic resonance image comprises a plurality of pixel points, and each pixel point has a corresponding pixel signal; acquiring a plurality of candidate relaxation times, and performing image simulation processing by using the plurality of candidate relaxation times and a preset echo time to obtain simulation pixel signals which are respectively corresponding to the candidate relaxation times and are matched with the intensity of the target emission field; the target emission field intensity is the emission field intensity of the position where the pixel point is located; and determining the difference degree between each simulation pixel signal and the pixel signal, and taking the candidate relaxation time corresponding to the simulation pixel signal with the minimum difference degree as the target relaxation time of the pixel point. By adopting the method, the accuracy of the relaxation time can be improved.
Owner:SHANGHAI UNITED IMAGING HEALTHCARE

Oil level online monitoring method based on ultrasonic waves

The invention relates to an online oil level monitoring method based on ultrasonic waves. The online oil level monitoring method specifically comprises the steps that ultrasonic probes are mounted at the bottom and the outer wall under an oil conservator in an adsorption mode through an ultrasonic coupling agent; ultrasonic waves enter the oil conservator through the coupling agent and are reflected when reaching the surface of the oil level in the oil conservator, a propagation path is calculated according to echo time, and then the height of the oil level is obtained; aiming at interference influence, measurement compensation is carried out, and a final result is corrected; the multi-frequency ultrasonic measuring sensor measures the height of the oil level in the oil conservator in real time and transmits the height to the system background; the multi-frequency ultrasonic measurement sensor compares the measured data with the reading of the traditional oil level gauge, and regularly performs online verification on the mechanical oil level; on the basis of online monitoring data, a corresponding relation graph of the oil level of the oil conservator, the environment and the working condition is established, and pre-judgment and early warning are achieved; based on the echo data information, the operation state is judged through a multivariate statistical analysis algorithm; the method has the advantages that the false oil level can be quickly distinguished, and the detection redundancy is increased.
Owner:STATE GRID HENAN ELECTRIC POWER CORP MAINTENANCE CO

Bolt pre-tightening force prediction method based on ultrasonic echo time-frequency characteristics

The invention discloses a bolt pre-tightening force prediction method based on ultrasonic echo time-frequency characteristics, and the method comprises the steps: S1, carrying out the ultrasonic excitation of a target bolt, obtaining an ultrasonic echo signal generated by the bolt, and carrying out the time-frequency analysis, and forming an initial time-frequency characteristic matrix; s2, according to a bolt material characteristic database, determining characteristic parameters of ultrasonic echo propagation corresponding to a target bolt material, and performing weighting processing on the initial time-frequency characteristic matrix to obtain a weighted time-frequency characteristic matrix; s3, extracting a time-frequency characteristic index through the weighted time-frequency characteristic matrix, and forming a target characteristic vector; and S4, inputting the target feature vector into the trained double-branch prediction model, outputting a pre-tightening force energy feature value and a pre-tightening force state change value, inputting the pre-constructed neural network model, and outputting a bolt pre-tightening force prediction value. According to the method, the bolt pre-tightening force can be predicted with high precision and high reliability, and the technical problems of low prediction precision and great environmental influence are solved.
Owner:CHENGDU TECHNICIAN COLLEGE (CHENGDU VOCATIONAL & TECH COLLEGE OF IND & TRADE CHENGDU ADVANCED TECH SCHOOL CHENGDU RAILWAY ENG SCHOOL)

Insulation silicone rubber thermal aging state detection method, device and equipment based on cable accessory

The invention relates to a cable accessory-based insulation silicone rubber thermal aging state detection method, apparatus and device. The method comprises the steps of obtaining a correlation model and a to-be-detected sample; transmitting ultrasonic waves to the to-be-detected sample for aging test to obtain a primary echo time domain signal; processing the primary echo time domain signal to obtain a spectrogram, and extracting a fundamental wave amplitude and a second harmonic amplitude from the spectrogram; calculating a relative nonlinear coefficient according to the fundamental wave amplitude and the second harmonic amplitude; and inputting the relative nonlinear coefficient into the correlation model for analysis to obtain the thermal aging degree. The method comprises the following steps: transmitting and receiving ultrasonic waves to and from a sample to be detected to obtain a primary echo time-domain signal, processing the primary echo time-domain signal to obtain a relative nonlinear coefficient, and inputting the relative nonlinear coefficient into a correlation model to analyze and evaluate the thermal aging degree of the identified thermal aging state of the sample to be detected. The microstructure change of the to-be-detected sample caused by thermal aging can be accurately captured, and the thermal aging state can be accurately evaluated.
Owner:ELECTRIC POWER RES INST CHINA SOUTHERN POWER GRID CO LTD +1

Method and system for identifying environment abnormity in direct current battery swap station

The invention provides a method and a system for identifying environment abnormity in a direct-current battery swap station. The method comprises the following steps: fusing multi-source images acquired by the direct-current battery swap station; determining at least one suspected abnormal region based on the fused image; constructing a three-dimensional structure model of an object in the suspected abnormal area based on reflection deformation information of structured light projected into the suspected abnormal area for multiple times; determining reflection change information of the object in the suspected abnormal area based on reflection echo intensity and reflection echo time of the obtained ultrasonic wave on the surface of the object in the suspected abnormal area; and performing logic correlation analysis based on the three-dimensional structure model and the reflection change information, and determining a target abnormal region in the to-be-identified direct-current battery swap station. According to the method and the system, the capability of identifying tiny and hidden abnormal objects of the direct-current battery swap station is greatly improved, missed judgment is effectively reduced, the accuracy and the reliability of environment abnormity identification in the direct-current battery swap station are improved, and stable operation of the battery swap station is guaranteed.
Owner:CSG EHV POWER TRANSMISSION +1

Method for acquiring a magnetic resonance image dataset

A method for acquiring a magnetic resonance image dataset of a field-of-view using a gradient-echo imaging protocol includes acquiring additional k-space lines within a central region of k-space at intervals throughout the imaging protocol, wherein the additional k-space lines are used for estimating motion parameters of the field-of-view. The imaging protocol has been amended by inserting additional gradient blips after at least some of the RF excitations, such that at least one additional gradient echo is generated, allowing the acquisition of at least one additional k-space line during one echo time.
Owner:SIEMENS HEALTHINEERS AG +1

High-precision wind measurement system based on double-frequency ultrasonic waves and measurement method thereof

The invention relates to the technical field of ultrasonic wind measurement, in particular to a high-precision wind measurement system and method based on double-frequency ultrasonic waves, and the method comprises the steps: deploying an orthogonal double-frequency ultrasonic transducer array in a horizontal plane, capturing an echo timestamp, and solving the wind speed through the dynamic changes corresponding to the high and low frequency characteristics; according to the forward and reverse wind round-trip time difference of the double-frequency ultrasonic waves on the X axis and the Y axis, the real-time temperature obtained through temperature compensation is combined, the wind speed components of the high-frequency ultrasonic waves and the low-frequency ultrasonic waves are calculated according to a forward and reverse wind formula, the X-axis final wind speed component and the Y-axis final wind speed component are obtained through weighted averaging, the wind direction angle is calculated according to an arc tangent function, and wind speed and direction results are output after quadrant correction; the wind speed and direction data obtained through calculation are preprocessed, and finally the processed data are stored in an internal storage. Double-frequency ultrasonic waves are adopted, high frequency is used for capturing rapid wind speed changes, low frequency is used for long-distance propagation to reduce environmental noise influences, the wind speed is solved in combination with a sound velocity formula, temperature compensation and a propagation equation, and high-precision measurement can be achieved.
Owner:NINGBO HANGNING INFORMATION TECHNOLOGY CO LTD

Relaxation exchange magnetic resonance imaging REXI sequence, acquisition and analysis method and application of relaxation exchange magnetic resonance imaging REXI sequence in measurement of cerebrospinal fluid transmembrane transport

The invention provides a relaxation exchange magnetic resonance imaging REXI sequence. A filtering module is composed of a 90-degree excitation radio frequency pulse and a 180-degree refocusing radio frequency pulse; the switching module is composed of a 90-degree excitation radio frequency pulse and switching delay; the detection module is composed of a 90-degree excitation radio frequency pulse and a plurality of 180-degree refocusing radio frequency pulses; paired crushing gradient pulses are applied to the filtering module and the detection module; and applying a phase-disturbing gradient pulse to the switching module. The invention further discloses an acquisition and analysis method of the REXI sequence, in REXI acquisition, the echo time of the filter module is fixed, and only the exchange delay time of the exchange module and the echo time of the detection module are changed; and performing REXI analysis, and fitting data by adopting a double-chamber exchange model. The invention also discloses an application of the REXI sequence and the acquisition and analysis method thereof in magnetic resonance imaging measurement of cerebrospinal fluid transmembrane transport, and the REXI sequence is especially suitable for magnetic resonance imaging for rapidly measuring the molecular exchange speed between a short T2 component and a long T2 component in a two-component system.
Owner:ZHEJIANG UNIV +1

Submarine topography surveying and mapping method and system based on underwater robot

The invention discloses a submarine topography surveying and mapping method and system based on an underwater robot, relates to the technical field of underwater robots, and provides reliable basic data for measurement based on an original measurement point sound wave data set S, and extracts a multipath disturbance feature set F of each sonar scanning point; the multi-path interference in the underwater environment is effectively identified and represented, data are clustered through density clustering analysis, dense clusters and discrete points are successfully identified, then a disturbance residual Cc is obtained and compared with a preset interference judgment threshold Omap, each sonar scanning point is endowed with a multi-path label, and the multi-path interference in the underwater environment is effectively identified and represented. According to the method, the time sequence and the amplitude sequence of sonar scanning points are combined, the main path echo time of each measuring point is accurately obtained, the continuity of landforms is effectively judged, and high precision and stability of underwater topographic survey are ensured, especially in the aspects of multi-path interference elimination, main path reconstruction judgment and final accurate topographic reflection.
Owner:YANGJIANG POWER SUPPLY BUREAU OF GUANGDONG POWER GRID

Water quality pollution tracing method and system applied to wave radar sea area

The invention provides a water quality pollution tracing method and system applied to a wave radar sea area, and the method comprises the steps: firstly obtaining a sea area polarization echo time sequence set captured by a wave radar and a sea area pollutant characteristic set measured synchronously, and then carrying out the polarization characteristic deconstruction processing of the sea area polarization echo time sequence set; a polarization characteristic parameter set of each sea area block is obtained, then a pollutant molecular structure and a polarization reflection coefficient in the sea area pollutant characteristic set are associated and adapted with the polarization characteristic parameter set to generate a pollution polarization association map, and a polarization-driven pollution traceability model is constructed based on the pollution polarization association map. The method comprises the steps of inputting a pollution polarization correlation map and preset sea area ocean current parameters, outputting a traceability path set of pollutants and an initial pollution area boundary, finally analyzing an original diffusion starting point of the pollutants according to a polarization-driven pollution traceability model, and generating a pollution traceability report containing information such as coordinates of the initial pollution area. Therefore, a sea water quality pollution source can be accurately positioned.
Owner:SHANGHAI ZHIXING ENVIRONMENTAL TECH CO LTD

Ultrasonic imaging system and method based on heart surface, medium and product

The invention discloses an ultrasonic imaging system and method based on a heart surface, a medium and a product, the system comprises an ultrasonic detection assembly and an imaging terminal which are in communication connection, an ultrasonic transducer is packaged at the head end of an attached ultrasonic probe in the ultrasonic detection assembly, and an acoustic window on the ultrasonic transducer is planar; the ultrasonic transducer is used for being attached to the surface of the heart or the aorta, and the plane of the ultrasonic transducer is parallel to the plane of the acoustic window; and the imaging terminal is used for generating a sound velocity mask pattern according to the reference ultrasonic image, determining echo time delay data according to the sound velocity mask pattern, synthesizing and reconstructing the radio frequency signal data according to the echo time delay data to obtain an ultrasonic image, performing motion compensation on the image sequence, performing multi-modal fusion on the ultrasonic image subjected to motion compensation, and obtaining a final ultrasonic image. The problem of acoustic interference of anatomical structures such as the chest wall and the esophagus in a traditional echocardiography technology is solved, and real-time and high-quality image support is provided for cardiac surgery.
Owner:XIAN HUAFENG MEDICAL TECH CO LTD +2

Ultrasonic surface wave probe zero offset, leading edge and sound velocity calibration method

The invention discloses an ultrasonic surface wave probe zero offset, leading edge and sound velocity calibration method. The method comprises the following steps: 1) preparing and selecting a test block; 2) positioning a probe to be detected; 3) performing initial resetting, and zeroing a zero offset parameter and a leading edge parameter; 4) translating the probe, and determining the echo time of the last stage before the upper end angle signal disappears as a zero offset parameter; 5) moving the probe until the front edge of the probe is flush with the side surface of the test block, and determining the echo time at the upper end corner of the test block as a front edge parameter; 6) calculating and calibrating a sound velocity value by using the primary echo time at the lower end angle and the secondary echo time at the lower end angle; the standardization and calibration precision of the calibration process are improved, and measurement errors caused by an existing method can be avoided.
Owner:XIAN THERMAL POWER RES INST CO LTD +1

Flying bird detection radar device

The invention discloses a flying bird detection radar device, and relates to the technical field of radio distance measurement. The bird detection radar device comprises a wind speed sensor used for obtaining wind speed time sequence data; the flying bird detection radar is used for acquiring echo time sequence data of a flying bird; the server is used for acquiring distance time sequence data between the flying bird detection radar and the flying bird based on the echo time sequence data; updating the flight prediction data; and the bird repeller is used for repelling flying birds based on the updated flight prediction data. In the bird trajectory prediction analysis process, the influence of the wind speed and the wind direction on the bird flight trajectory is considered, so that the flight prediction data of the bird can be predicted more accurately. And the flying birds are accurately repelled based on the flight prediction data subsequently, that is, if the flying birds do not enter the early warning area in the future, the flying birds are not repelled, and if the flying birds possibly enter the early warning area in the future, the flying birds are repelled.
Owner:ZHONGAN RUIDA (BEIJING) ELECTRONIC TECH CO LTD