1409 results about "Reflected waves" patented technology

A radar device which is installed in a vehicle or the like needs to detect a target at a short distance from several tens of centimeters to several tens of meters and, therefore, has a problem that a reflected wave from the target may be reflected by a front case of the radar device and then reflected by the target again to be received as a secondary echo by itself. To solve this problem, it is an object of the present invention to provide a radar device again that can prevent multi-reflection to accurately measure a distance to a target in a short range. In a radar device according to the present invention, a surface of a frame body provided around a transmitting antenna and a receiving antenna is shaped so that a reflected wave from a target may not be returned in a direction in which a transmitting wave is transmitted from the transmitting antenna.

The invention relates to the technical field of cable fault detection, in particular to a cable fault analysis system based on big data, which comprises a disturbance feature extraction module, a time sequence hierarchy judgment module, a reflection characteristic analysis module, a topological section identification module and a fault path mapping module. According to the method, gradient inflection points are extracted by calculating voltage and current increment included angles at adjacent moments, spatial-temporal characteristics of disturbance signals are correlated, interference of noise to a starting point mark is reduced, time difference is fitted in combination with cable length, deviation over-threshold abnormal points are dynamically filtered, influences of synchronization errors on sorting are eliminated, and fault path mapping stability is improved; the method comprises the following steps: generating characteristic parameters by fusing amplitude values and wave crest intervals of main waves and reflection waves, quantifying amplitude attenuation and phase offset coupling, enhancing the multi-path superposed signal separation capability, judging the reflection characteristic similarity of a physical section based on a Manhattan distance and a support vector machine, and dynamically dividing a fault section in combination with line topology. The problem of fuzzy positioning in a branch parallel scene in a traditional method is solved.

The invention discloses a target positioning method and system based on a single reference station, and relates to the field of wireless positioning, and the method comprises the steps: generating vortex electromagnetic waves carrying orbital angular momentum based on a transmitting end of a reference station, and generating a time-varying phase modulation transmitting signal and a metasurface time-varying coding sequence through a programmable metasurface; a time-varying phase modulation emission signal forms a multipath superposition effect in a propagation environment, a receiving end obtains a mixed signal of a direct wave and a reflected wave, and the receiving end carries out OAM mode separation on the mixed signal of the direct wave and the reflected wave through a spiral phase plate and an annular array to obtain signal components in different modes; and based on the signal component and the metasurface time-varying coding sequence, reconstructing an equivalent virtual array response by adopting a compressed sensing algorithm. According to the invention, the orbital angular momentum modal separation technology and the metasurface dynamic coding technology are creatively fused, and high-precision real-time direction finding in a complex multi-path environment is realized under a single base station architecture.

The invention provides a distribution line fault location optimization method based on single-ended traveling wave location, and relates to the technical field of traveling wave detection. The method comprises the following steps: carrying out segmented modeling on a line, calculating the traveling wave propagation speed and wave impedance of each segment, and correcting the traveling wave propagation speed and wave impedance; collecting a voltage / current traveling wave signal of a detection point, and extracting a line mode component; performing wavelet transformation on the line mode component, detecting the wave head position of the initial traveling wave through a modulus maximum search algorithm, and recording the arrival time of the initial traveling wave, a corresponding first energy value and polarity; calculating a reflected wave time window based on segmented modeling parameters, screening reversed polarity waves with qualified energy attenuation, and calculating a fault distance; if no effective reflected wave is detected in the reflected wave time window, triggering a pseudo double-end mode; a result is verified through quadruple constraints; the problems of poor parameter adaptability, low signal processing precision, strong reflected wave dependence and incomplete verification in traveling wave distance measurement of a complex distribution line are solved, and the accuracy and reliability of fault distance measurement are improved.

The invention provides a defect positioning accurate identification method considering the change of the section of a pile body, and the method comprises the steps: carrying out the simulation comparison of a constructed sound wave signal feature vector and a pre-constructed sound wave feature vector of a defect-free pile foundation, calculating the feature difference degree of the two, setting a difference degree threshold value, and if the feature difference degree exceeds the threshold value, carrying out the recognition of the defect-free pile foundation. If yes, preliminarily determining that the pile body has defects; on the basis of the adjusted sound wave detection, sound wave signals are collected again, signal processing and feature extraction are conducted through a self-adaptive path tracking algorithm, and the three-dimensional coordinates of the defect in the pile body are calculated according to the time delay and the propagation speed of reflected waves by combining the established multi-reflection model and an inversion sound wave propagation path; and according to the calculated three-dimensional coordinates of the defect reflection points, the influence degree of the defects on the bearing capacity of the pile foundation is calculated by combining the defect size estimated through the amplitude of reflected waves, the defect type recognized through waveform features and the strength parameter of a pile body material through a finite element method.

The invention relates to a settlement data analysis and early warning method based on a cloud platform, and the method comprises the steps: collecting settlement data of a basic part of a main transformer in real time through a high-precision electronic settlement observation device array, obtaining deformation stress data through data preprocessing and coordinate calculation, and uploading the deformation stress data to the cloud platform; transmitting an ultrasonic pulse signal to the stress concentration position of the local area through ultrasonic detection equipment, receiving reflected wave data, and identifying the depth and range of the crack initiation position according to the reflected wave data; a sensor array is arranged on the basic surface of a crack initiation position, sound wave signals released in the crack propagation process are captured, and a time sequence of the crack propagation direction and speed is determined; and detecting crack depth data of the repair priority region through ultrasonic waves, calculating an adjusted basic health state value, comparing the adjusted basic health state value with a preset safety threshold, and generating a corresponding safety early warning signal.

The invention discloses a power distribution network three-core cable fault distance measurement analysis method and system, and relates to the technical field of fault distance measurement, and the key points of the technical scheme are that the method comprises the steps: carrying out the empirical mode decomposition of three-phase voltage and current signals; generating a dynamic correction wave velocity based on the cable type, the environment temperature and the soil humidity parameter; determining the first arrival time of the wave head of the initial traveling wave according to the instantaneous frequency abrupt change point of the alpha-mode component, screening the second arrival time of the first reflected wave by using the amplitude gradient of the zero-mode component, and calculating the arrival time difference; and calculating an initial fault distance, and calling the impedance matrix to iteratively correct the initial fault distance. According to the method, the dynamic wave velocity is coupled with multiple factors, the limitation of single parameter correction is broken through, and the problem of transient drift of the wave velocity is solved; and the STFT high-frequency resolution and the wavelet low-frequency stability are fused, and the ridge continuity is optimized in combination with dynamic programming, so that the traveling wave head detection precision can be improved.

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 discloses a textile production defect detection method and system based on image processing, and belongs to the field of textile defect detection. According to the method, the point cloud data is generated by collecting the surface deformation stripes, and the penetrability reflection signal containing the sound wave propagation time is obtained through the multi-frequency ultrasonic probe. Denoising the point cloud data and then positioning a surface deformation candidate area based on a curvature gradient and a normal vector deflection angle; and an internal abnormal region is determined by separating and extracting a reflection wave amplitude value and a time delay parameter through an ultrasonic frequency band. And matching the surface point cloud coordinates with the ultrasonic propagation time by adopting an iterative nearest point algorithm to establish feature association between the normal vector deflection angle and the reflected wave amplitude. And dynamically distributing fusion weights for the surface features and the internal features according to the curvature gradient change rate and the amplitude attenuation rate to generate a multi-modal defect distribution diagram. And geometric shape and reflection intensity parameters are extracted and matched with a preset defect template to realize type and position judgment, and the method can be suitable for production defect detection of the thick textile with a multi-layer composite material structure.

The invention relates to the technical field of power system fault positioning, in particular to a power distribution network fault accurate positioning method, device and system based on the traveling wave principle, and the method comprises the steps: deploying traveling wave detection equipment at two ends of a certain section of line of a power distribution network, and enabling the traveling wave detection equipment to be used for synchronously collecting potential fault traveling wave signals; analyzing based on the acquired potential fault traveling wave signal, and screening out a fault traveling wave; in the time union set of the local time windows at the two ends, marking the fault traveling wave with the maximum peak value in the single end as a direct wave, analyzing the waveform similarity between the direct wave and the fault traveling wave arriving after the direct wave, and screening out a reflected wave according to the peak value difference; and based on the arrival time of the direct waves and the reflected waves at the two ends, calculating the distance from the fault point to the two ends of the line through a positioning formula to position the fault point. The invention aims to improve the positioning precision of the fault point in the power distribution network by analyzing the distribution characteristics of the pseudo traveling wave signal.

The invention provides a blade lightning protection channel online test method and system based on a pulse current method, and belongs to the technical field of blade lightning protection detection.The method comprises the steps that a pulse waveform is generated through a pulse current generator to simulate lightning impulse, and the lightning impulse is injected into the surface of a lightning arrester of a blade lightning protection system; measuring channel currents at different positions of the surface of the lightning arrester in the length direction by using a distributed sensor; a high-voltage differential probe is used for collecting and measuring the waveform of an incident wave and the waveform of a reflected wave of an injection point; detecting blade surface potential distribution by using a capacitive coupling sensor; comparing the waveform of the incident wave, the waveform of the reflected wave and the theoretical waveform, determining a time domain reflection coefficient and a frequency domain impedance spectrum, and determining a fault type; after the fault type is determined, the fault point is positioned based on the channel current and the blade surface potential distribution, the lightning impulse is simulated through the pulse waveform, the lightning protection channel is further tested, shutdown is not needed, the testing efficiency of the blade lightning protection channel is effectively improved, and the power generation efficiency is ensured.

The invention relates to the technical field of satellite altimetry, in particular to a height measurement method based on a feature-enhanced multi-base integrated re-tracking model, which is characterized in that the feature-enhanced multi-base integrated re-tracking model FMERM is constructed to optimize the position of a reflection waveform re-tracking point, and the FMERM model executes the following processing processes: 1, extracting input variable features by using PCA, and extracting the input variable features by using PCA; combining with an original input variable to form an enhanced feature set; secondly, optimizing the hyper-parameters of the XGBoost model by using a grid search method, so that the hyper-parameters of the XGBoost model are optimal; thirdly, utilizing the trained model to accurately calculate a re-tracking point normalization power value of the reflected signal waveform; fourthly, the sea surface height is inverted through the geometrical relationship and direct reflection signal time delay and atmospheric correction; an effective means is provided for solving the problem that a reflection waveform re-tracking method is inaccurate, and powerful support is provided for high-precision satellite-borne GNSS-R sea surface height measurement.

The invention relates to the technical field of reflected waves, in particular to a coal mine disaster comprehensive evaluation system based on three-component micro-motion detection, which comprises a frequency direction extraction module, a propagation included angle calculation module, a sensitive path identification module, a critical turning identification module and a structural disturbance mapping module. According to the method, the continuous sequence is formed in the space through the direction vector constructed through the main frequency value of the measuring point, an included angle screening strategy is used for eliminating incoherent direction sections, it is ensured that the path has trend consistency, the frequency amplitude difference value and symbol inversion are used for detecting a mutation point, and the response recognition capacity for directional changes is enhanced; the normalized frequency ratio is combined with a standard deviation and a difference value to carry out joint calculation so as to quantify a structure jump degree and improve the accuracy of reflex position expression, disaster boundary points form an image set, and a structure identification channel is established by taking a frequency direction as a principal line; and the spatial expression definition and precision are improved in the aspects of path aggregation, boundary precision, disaster recognition and partition and continuous structure drawing.

The invention discloses a wind driven generator blade lightning conductor broken line point positioning method based on a radio frequency transformer, and relates to the field of wind driven generator blade lightning conductor broken line point positioning. A to-be-detected line is connected in series with the radio frequency transformer before being injected into traveling waves, and the change of traveling wave current is converted into the change of transformer output voltage; therefore, the output voltage of the radio frequency transformer is detected to judge the arrival time difference of the incident wave and the reflected wave, and then the breakpoint position is judged by multiplying the wave velocity by the time difference and dividing by 2. According to the wind driven generator blade lightning conductor breaking point positioning method based on the radio frequency transformer, the position of the lightning conductor breaking point can be efficiently, accurately, conveniently and flexibly detected at low cost, positioning measurement of disconnection of a multi-core wire part can be achieved, the specific positions of the breaking point and an abnormal point of the lightning conductor can be effectively determined, and the working efficiency is improved. After the positions of the broken line point and the abnormal point are determined, specific positions are repaired in a targeted manner, so that the cost for replacing the lightning conductor is saved.

A method for analysing a sample comprising a layer having a first interface and a second interface, the method comprising: Irradiating the sample with a pulse of terahertz radiation, said pulse comprising a plurality of frequencies in the range from 0.01 THz to 10 THz; Detecting radiation reflected from the sample to produce a sample waveform; Obtaining a first reflection waveform from the sample waveform, the first reflection waveform corresponding to the reflection from the first interface; Obtaining a second reflection waveform from the sample waveform, the second reflection waveform corresponding to the reflection from the second interface; Comparing the first reflection waveform with the second reflection wave-form to produce an estimate of a thickness and a complex refractive index of the layer; Producing a synthesised signal using the estimate of the thickness and complex refractive index; Varying at least one of the thickness and complex refractive index to reduce an error between the sample waveform and the synthesised signal; and Outputting the thickness of the layer.

The invention discloses a method, a system, equipment and a medium based on a multi-composite ultrasonic penetration technology, and the method comprises the steps: generating high-frequency fundamental ultrasonic waves through a piezoelectric transducer array, and adjusting the frequency range to match the acoustic impedance characteristic of target soil; first, second and third harmonics are generated through the induction of a nonlinear medium in the fundamental wave propagation process, the phases of the harmonics are adjusted to realize coherent superposition, and the fundamental wave and the first, second and third harmonics are guided into a composite waveguide device for focusing and delay compensation to form a high-energy composite wave beam; a pulse interval is adjusted by adopting an intermittent emission strategy so as to inhibit energy attenuation in the soil; reflected wave spectrum components are monitored through an embedded acoustic sensor array, and driving parameters are dynamically adjusted; and residual ultrasonic energy is captured and fed back to a driving circuit to form a closed-loop energy utilization system. By integrating multi-order harmonic resonance and a dynamic frequency tuning technology, efficient transmission and deep penetration of ultrasonic energy in a complex medium are realized.

The invention discloses a VSP wellbore wave suppression method for improving U-Net based on physical constraints, which comprises the following steps: introducing apparent velocity constraints of an F-K transform domain, constructing physical constraint conditions, simultaneously realizing time sequence feature extraction and prediction of wellbore waves in combination with a GRU network, and learning a mapping relation between a noise image and a clean image by using the network so as to improve the suppression efficiency of the wellbore waves. The details and the structure of a noise image are accurately restored through a training network, the difference between a real de-noised image and network output is minimized so as to achieve the purpose of image de-noising, the model retains effective signals through a residual learning mechanism, and meanwhile precise suppression of shaft wave noise is achieved. The method provided by the invention can accurately identify and effectively suppress wellbore waves and reflected waves thereof in a complex VSP wave field, significantly improve the signal-to-noise ratio, reduce residual noise, improve data processing efficiency while improving data quality, provide technical support for high-precision seismic imaging under a complex geological condition, and have a wide application prospect. And meanwhile, a feasible solution is provided for popularization and application in an actual work area.

The invention provides an aero-engine blade damage detection method based on an improved ultrasonic sparse reconstruction algorithm, and relates to the technical field of aero-engine damage detection positioning, and the method comprises the steps: S1, setting a sensor array and a detection region of a to-be-detected blade, and obtaining an actual measurement damage reflection signal dictionary through a sensor; s2, wave number distribution of a detection area is determined according to a variable thickness structure Lamb wave propagation model, signal reconstruction is carried out, and a theoretical damage reflection signal dictionary is obtained; s3, an aero-engine blade damage detection model is constructed, an improved sparse reconstruction algorithm is adopted to solve and optimize, and damage judgment is carried out; and S4, according to the pixel value distribution condition of the aero-engine blade detection area, generating an aero-engine blade damage detection image, and positioning a damage position. According to the method, the reflected wave amplitude information can be obtained from the array sensor signals, and the reflected wave amplitude information is compared with the reconstructed theoretical reflected signals, so that the damage condition of the aero-engine blade is identified and positioned.

The invention discloses a seismic surface wave suppression method based on EWT-Curvelet, and belongs to the technical field of seismic exploration data processing. The method comprises the following steps: firstly, performing empirical wavelet transform (EWT) on post-stack seismic data channel by channel, extracting a frequency localized modal component through adaptive spectrum segmentation, and constructing a surface wave noise model; then converting the model to a curvelet domain, performing physical constraint filtering at a specific scale and in a nearly horizontal direction, and combining pixel connectivity analysis to suppress a continuous noise region; and finally, reconstructing and optimizing noise through inverse transformation and removing the noise from the original data. The method has the advantages that the modal aliasing problem is solved through channel-by-channel adaptive spectrum segmentation, a surface wave energy dense region is accurately locked by curvelet domain scale-direction combined filtering, isolated effective signals are protected in combination with connectivity analysis, high-precision suppression of surface waves is efficiently achieved in a non-iterative mode, meanwhile, the structural integrity of reflected waves is kept, and high-precision suppression of the surface waves is achieved. The seismic section signal-to-noise ratio and the geological interpretation precision are remarkably improved, and the method is suitable for land seismic exploration data processing.

The invention provides a multivariate numerical analysis method and system based on a TEHB test system, and the method comprises a multidirectional synchronous impact test numerical simulation step: building a rock numerical model with a real mineral structure and breakable mineral crystals, and constructing a single-axis bidirectional synchronous impact test simulation frame, the multi-directional synchronous impact test simulation module is used for implementing multi-directional synchronous impact test numerical simulation on the rock numerical model; a dynamic response index calculation step: separating and recombining the incident wave signal and the reflected wave signal obtained by monitoring, and obtaining a dynamic response index of the rock numerical model in the impact process; and a multi-element parameter intelligent analysis step: during numerical simulation of the multidirectional synchronous impact test, displaying spatial distribution characteristics of different types of cracks in real time, and realizing intelligent microscopic analysis of crack evolution, rock damage and energy characteristics. According to the invention, the dynamic mechanical behavior of the rock under the impact load can be simulated, and the real-time fracture information in the rock can be displayed more visually.

The invention provides a diffracted wave separation method and device under non-uniform space-time sampling, and relates to the technical field of seismic prospecting, the method comprises the following steps: obtaining common offset seismic data of a target area, the common offset seismic data comprising fluctuation signals of a plurality of sampling points, the position intervals among the sampling points of different seismic traces are non-uniform, and / or the time intervals among different sampling points of the same seismic trace are non-uniform; calculating the plane wave slope of each sampling point of the common offset seismic data through a finite difference method to obtain plane wave slope data; determining a reflected wave travel time curve of each sampling point according to the plane wave slope data; and diffracted wave separation of the common offset seismic data is carried out according to the reflected wave travel time curve of each sampling point. According to the method, accurate diffracted wave separation under non-uniform space-time sampling is realized, and the seismic data analysis accuracy is improved.

The invention provides a shale reservoir fracture prediction method and system based on three-dimensional full-waveform inversion and a medium, and relates to the technical field of data analysis, and the method comprises the steps: arranging a multi-channel seismic exploration instrument in a shale reservoir region, and collecting full-waveform seismic data, including longitudinal waves, transverse waves and reflected waves; performing three-dimensional full-waveform inversion based on the logging data, the geological structure map and the full-waveform seismic data to generate a shale reservoir attribute model; a multi-scale inversion strategy is constructed, fracture sensitivity analysis and fracture form dynamic prediction are carried out, and reservoir fracture distribution characteristics and reservoir fracture form characteristics are obtained; discrete fracture point connection and fracture network reconstruction are carried out, a reservoir three-dimensional fracture network model is constructed, and fracture prediction visualization display is carried out. The technical problems that in the prior art, only inference based on limited data can be provided, comprehensive capture of a complex fracture network is lacked, distribution and form of fractures cannot be comprehensively and accurately described, and reservoir analysis and mining decisions are affected are solved.

An information processing device including: a control unit configured to: acquire at least one frame image generated by using line data indicating intensity of a reflection wave with respect to an ultrasound radially transmitted from an ultrasound transducer moving inside a biological tissue, and extract a specific region from the at least one frame image based on a ratio between an average of luminance in a region of interest included in the at least one frame image and a dispersion of luminance in the region of interest.

The invention relates to the field of roadway surrounding rock loosening circle test and analysis, in particular to a roadway surrounding rock loosening circle test and analysis method, which comprises the following steps: data acquisition: distinguishing the current roadway area, and acquiring parameter information of roadway surrounding rock through devices; the deep loose zone analysis is to analyze each displacement parameter of the deep roadway surrounding rock corresponding to each monitoring time point; according to the obtained reflected wave amplitude parameter values and the reflected wave frequency parameter values, the position information of the surrounding rock loose circle is analyzed; according to the remote safety monitoring, the state information of the surrounding rock loosening circle is monitored in real time, and when a threshold value is exceeded, an audible and visual alarm is given out, the loosening circle range obtained by each method is preliminarily determined, and then the loosening circle range is determined by comprehensively comparing the test results of each method in the same area; and the range and characteristics of the loose circle can be judged more comprehensively and accurately.

The invention relates to a tide level obtaining method and system based on an OWC wave energy conversion device. The method comprises the following steps: constructing an energy loss prediction model in the air chamber; acquiring field incident wave energy, reflected wave energy, water potential energy increment, kinetic energy increment and pneumatic output energy at the current time period; inputting incident wave energy and reflected wave energy into the model to obtain predicted energy loss; and the tide level variation is solved based on the energy conservation relational expression, and the current tide level is calculated. The system comprises an energy loss prediction module, a wave energy acquisition module, a water body energy acquisition module, a pneumatic output acquisition module, an energy loss calculation module, a tide energy solving module and a tide level calculation module, which cooperatively realize the method. According to the scheme, an external tide gauge station is not needed, the local sea area tide level can be inversed in situ, at high frequency and with high precision, the method is suitable for an OWC-breakwater fusion scene, and cooperative operation of a port and ocean energy is supported.

The invention discloses an ultra-deep reflection imaging method based on passive source seismic data and a related device, and relates to the technical field of earth depth structure imaging, and the method comprises the following steps: firstly, for original continuous seismic waveform data, intercepting seismic waveform data with a first arrival of a P wave and a non-arrival of an S wave, and carrying out the preprocessing of the data, so as to obtain a far earthquake event data segment; the method comprises the following steps: firstly, analyzing and identifying a far earthquake event with a high signal-to-noise ratio by using a time-frequency-wavenumber domain, removing data which are greatly influenced by noise, and then, reconstructing a reflection wave field of a high-quality far earthquake data fragment by using a multi-dimensional deconvolution technology, and carrying out convolution on a seismic source wavelet to obtain ultra-deep reflection wave field data. And finally, performing reflection imaging processing in combination with velocity analysis and superposition imaging technologies, optimizing the analysis capability of a deep reflection interface, and finally obtaining an earth deep reflection imaging profile, so that a continuous structure interface extending from the shallow earth crust to the deep mantle can be clearly revealed, and coupling characteristics between shallow and deep earth structures can be effectively captured.

The invention provides a line fault positioning method, system and device and a storage medium, relates to the technical field of current collection line monitoring and is used for realizing fault positioning in a tail end area of a current collection line, the method is applied to control equipment in the line fault positioning system, and the line fault positioning system further comprises a traveling wave injection device. The method comprises the following steps: a control device obtains a first moment when a traveling wave injection device injects a traveling wave signal at the tail end of a current collection line and a second moment when the traveling wave injection device collects a reflected wave; furthermore, the control device determines a target distance between the fault point and the tail end of the current collection line according to the first moment, the second moment and the traveling wave speed of the traveling wave signal, and the target distance is used for representing the position of the fault point.

The invention discloses a fault positioning method based on impedance abrupt change point detection and related equipment, relates to the technical field of power transmission line fault positioning, and solves the problem that an impedance abrupt change point of a power transmission line is easily misjudged as a fault point. According to the invention, the fault point reflection wave and the impedance abrupt change point reflection wave of the fault traveling wave model are identified through the instantaneous frequency of the fault traveling wave signal, so that the misjudgment rate of the fault point can be reduced; by dividing the first line section near the impedance abrupt change point and the second line section farther from the impedance abrupt change point, respectively calculating the corresponding first wave velocity and second wave velocity, and then calculating the fault point distance based on the first wave velocity and the second wave velocity, the positioning precision can be improved.

The invention provides a transcendental extreme ultraviolet light source device which comprises a free electron laser main body which comprises an undulator system and an optical resonant cavity. The undulator system comprises a modulation section undulator and a radiation section undulator; the optical resonant cavity comprises resonant cavity reflectors and a dispersion section, and the modulation section undulator, the dispersion section undulator and the radiation section undulator are sequentially arranged in the direction of an electron beam and are all located between the resonant cavity reflectors; the resonant wavelength output by the radiation section undulator is 1 / h of the resonant wavelength of the modulation section undulator, h is the harmonic number, and when the resonant wavelength output by the radiation section undulator is 6-7nm, the radiation wavelength reflected by the resonant cavity is h times of the resonant wavelength output by the radiation section undulator, so that the resonant cavity is prevented from adopting a reflector with the reflection wavelength of 6-7nm. According to the device, the radiation of the target wavelength is output by using harmonic waves, and a reflector with relatively long wavelength and mature technology can be directly used; various accelerators are compatible, the energy efficiency of the accelerators is greatly improved, and power consumption is reduced.

The invention provides a circular pool wave making system and a wave making and absorbing method, and belongs to the technical field of ocean engineering equipment.The circular pool wave making system comprises a plurality of wave maker units distributed around the circumference of a circular pool at equal intervals; the wave maker unit comprises a linear motor; the linear motor is connected with a floater through a connecting rod; the linear motor is connected with the driver, the driver is connected with the upper computer, the upper computer sends a control command to the driver, and the floater floats on the water surface and has a motion freedom degree of vertical translation. By controlling the movement of each wave maker unit in the circular pool wave making system, full-circumferential wave making is realized, regular waves, irregular waves, rotating waves, annular focused waves and other focused waves in any shape can be made, and meanwhile, waves propagated to the periphery of a pool are absorbed based on an active wave absorbing technology, so that the wave making efficiency is improved. Therefore, various wave making requirements, including simulation of real sea conditions and wave making of extreme sea conditions, are met.