132 results about "Resistivity distribution" patented technology

The invention discloses a while-drilling azimuth electromagnetic wave logging information real-time inversion method, and relates to the technical field of oil exploration and development, and the method comprises the steps: building various horizontal stratum models, carrying out logging forward modeling, and obtaining a response signal library; based on the response signal library, designing a while-drilling azimuth electromagnetic wave logging inversion model; inputting logging information, and automatically processing the information by using a zoom fidelity method; a neural network algorithm is introduced, a stratigraphic model integration multi-initial-value strategy is established, and initial value optimization is carried out for actual logging information; on the basis of a regularization gradient optimization algorithm and the initial value, upper / lower interface positions and resistivity distribution of the instrument are extracted in real time; and carrying out statistical processing on multiple groups of inversion results to obtain a final stratum model and the credibility of each inversion parameter. According to the method, the problems that while-drilling electromagnetic wave logging information is significant in difference, the target function changes severely and the minimum values are multiple can be solved, and a constraint and optimization method is provided for inversion initial value selection.

The invention discloses a coal seam working face floor detection and analysis method, and relates to the technical field of detection and analysis. Potential change conditions of different positions and different elevations are observed through a parallel electrical method instrument, resistivity distribution conditions of different depths in a working face and a bottom plate of the working face can be obtained through three-dimensional electrical method inversion, and the resistivity distribution conditions provide technical support for objective and accurate geological interpretation. The hydrogeological condition of the working face floor rock stratum can be better understood, so that an important reference basis is provided for safe mining; the thermal effect and the electromagnetic effect existing in the environment are evaluated and corrected, so that the deviation of the measured conductivity value can be accurately corrected, and the accuracy and the reliability of conductivity measurement data are improved; and inputting the corrected conductivity value SR (xi, yi, zi) of each grid point into a three-dimensional model, and marking to construct a conductivity three-dimensional model, so as to visually display the electrical property distribution information of the underground medium.

The invention discloses a tower grounding grid multi-frequency composite wave electric field imaging and soil environment medium diagnosis method, which comprises the following steps of: generating a composite excitation signal through superposition of a low-frequency sine wave and a high-frequency CHIRP square wave, and collecting multi-dimensional data such as voltage / current response, soil temperature and humidity, electric field intensity and the like in combination with a distributed sensor array; separating signal features by using wavelet transform and extracting impedance information of a target frequency point; a multi-grid homotopy algorithm is adopted to realize grounding grid three-dimensional resistivity distribution reconstruction, corrosion spots and abnormal areas are marked, and high-precision positioning of underground conductors is completed through UWB radar or a capacitance detector; meanwhile, based on the information entropy maximization optimization frequency band combination, the grounding grid state is comprehensively evaluated in combination with a multi-parameter fusion model. The method has the non-contact patrol capability, the unmanned aerial vehicle carries equipment to scan the grounding grid, the detection efficiency and convenience are remarkably improved, and an efficient and accurate solution is provided for guaranteeing safe operation of the power grid.

The invention relates to a SiC crystal ingot facet detection method based on Raman combined with resistivity detection, which comprises the following steps: S1, providing a silicon carbide workpiece, acquiring resistivity rho k of different detection areas on the surface layer of the workpiece based on a preset resistivity detection scanning path, and further preliminarily screening out resistivity abnormal areas; s2, on the basis of a preset Raman detection scanning path, obtaining the edge area on the surface layer of the workpiece, the Raman characteristic peak frequency omega ij of different detection points of the resistivity abnormal area obtained in the S1, a detection image, and an XY coordinate position on an XY plane perpendicular to the height direction of the workpiece; and S3, based on a preset n-rho inverse proportion function model of the doping concentration n and the resistivity rho, and a delta omega-n linear model of the Raman frequency shift delta omega and the doping concentration n, determining and associating the XY coordinate positions of the S2 and the corresponding resistivity rho ij, and constructing a resistivity distribution diagram of the surface layer of the workpiece. The method has the advantages of small detection error and short detection time.

The invention belongs to the technical field of semiconductor device performance testing, and particularly relates to a VCSEL epitaxial wafer resistivity distribution measuring method and system, and the method comprises the steps: constructing a three-dimensional discretization model representing an epitaxial wafer and an unknown parameter vector containing the vertical resistivity, the top transverse resistivity and the substrate leakage junction nonlinear resistance; a physical response function is defined, the vector is iterated through a discrete point fitting algorithm, so that the total residual error between the analog voltage difference output by the function and the actually measured voltage value under the cross-order-of-magnitude current is minimum, and the real vertical resistivity is extracted from the optimal parameter vector; and obtaining the vertical resistivity of each point on the two-dimensional test point grid so as to generate a distribution diagram and carry out anomaly detection. According to the invention, the problem of measurement distortion caused by the leakage defect of the substrate is solved, and the measurement accuracy of the vertical resistivity is improved.

The invention provides a fluid identification method, device and equipment and a storage medium, and the method comprises the steps: obtaining the geological information data of a to-be-identified region, building a plurality of well-connecting stratigraphic framework profiles, and calibrating the horizon; obtaining first wide-area apparent resistivity data of all layers in the to-be-identified area and second wide-area apparent resistivity data of a target layer in the to-be-identified area, and replacing the data of the target layer in the first wide-area apparent resistivity data with the second wide-area apparent resistivity data to obtain an electrical comprehensive data volume; carrying out joint constraint inversion according to the multiple well-connected stratigraphic framework profiles and the electrical comprehensive data volume to obtain multiple inversion apparent resistivity distribution profiles, determining a target inversion apparent resistivity distribution profile, obtaining a wide-area fluid identification standard, carrying out fluid identification division on the multiple inversion apparent resistivity distribution profiles, and carrying out fluid identification division on the wide-area fluid identification standard. And further obtaining a fluid plane identification result of the to-be-identified area. According to the invention, high-precision fluid identification of the target layer in the to-be-identified area can be realized through the logging data and the electromagnetic data.

The invention discloses a three-dimensional oil saturation imaging method and system based on multi-frequency electromagnetic-acoustic wave coupling, and the method comprises the following steps: transmitting an electromagnetic wave signal to a stratum through a multi-frequency electromagnetic array, and receiving an electromagnetic response signal reflected by the stratum; synchronously transmitting high-frequency sound wave pulses, collecting sound wave reflection signals and extracting stratum interface information; the formation resistivity distribution is calculated based on the electromagnetic response signal, the formation boundary is constrained by combining the sound wave reflection signal, and the resistivity multiplicity is eliminated through a joint inversion algorithm; utilizing a deep learning model to fuse electromagnetic and sound wave data, and constructing an oil saturation three-dimensional grid model; and three-dimensional saturation distribution is dynamically displayed through a visual platform, and injection-production scheme optimization is guided. The method is high in resolution, low in condition dependence degree, low in cost and high in modeling precision, achieves three-dimensional perspective oil reservoir through multi-physics field coupling and high-precision three-dimensional modeling, is suitable for remaining oil potential tapping, unconventional oil and gas development and carbon sequestration monitoring, and facilitates intelligent oil field construction.

The invention discloses a transient electromagnetic data polarizability extraction method based on frequency domain resistivity, and the method comprises the following steps: designing measuring line and wire emission source positions in a test mining area, selecting observation parameters, and collecting field electromagnetic data, the field electromagnetic data comprising transient electromagnetic method electric field data and frequency domain electromagnetic method electric field data; performing inversion on actually measured frequency domain electromagnetic method electric field data by adopting an Occam inversion algorithm to obtain resistivity characteristics of different measuring points, and further obtaining resistivity distribution information; and taking the resistivity distribution information obtained by inversion as a constraint condition of transient electromagnetic method electric field data inversion, performing transient electromagnetic method polarizability inversion by analyzing a relationship between the resistivity and a time constant, and extracting the polarizability. By analyzing and processing the frequency domain electromagnetic data and the time domain electromagnetic data, the resistivity and the polarizability can be accurately extracted, parameter separation is achieved, and the problem of traditional time domain inversion coupling is solved.

The invention discloses a geotechnical engineering investigation measuring method, medium and equipment, and relates to the geotechnical engineering investigation related technical field, and the measuring method comprises the following steps: deploying a composite sensor network comprising a geological radar, a high density electrical method instrument, a micromotion array and an optical fiber strain sensing unit; electromagnetic characteristics, resistivity distribution, an excellent period and soil deformation are collected; eliminating industrial interference and biological activity non-target signals by using an adaptive threshold denoising algorithm based on wavelet packet decomposition; and a double-flow CNNLSTM hybrid network is constructed, and feature level fusion is realized through attention mechanism dynamic weight distribution. According to the invention, by deploying the composite sensor network, synchronous acquisition of electromagnetic characteristics, resistivity distribution, excellent period and soil deformation is realized. The precision and resolution of data acquisition are improved, a shallow underground medium interface can be detected, and a low-resistance abnormal zone can be identified.

The invention relates to a mine roadway exploration method, system and device and a medium, and the method comprises the steps: carrying out the exploration of a to-be-detected region of a mine through employing an equivalent antimagnetic flux transient electromagnetic method, and obtaining an abnormal resistivity distribution condition; using a high-density resistivity method to determine the profile resistivity distribution condition based on the abnormal resistivity distribution condition; based on the abnormal resistivity distribution condition and the profile resistivity distribution condition, determining the position of an initially measured roadway; verifying the position of the primarily measured roadway to obtain the position of a target roadway; and performing drilling scanning on the target roadway position to obtain target survey information. The problems that in the prior art, the roadway position determined by directly surveying the ground surface environment of a roadway with complex physical property characteristics is large in error, the difficulty of source treatment is large, and the efficiency is low are solved.

The invention discloses an electrical source transient electromagnetic ground-air detection method and system, and relates to the technical field of geophysical exploration. The method comprises the following specific steps: arranging a transient electromagnetic transmitting device and a receiving device in a detection area; carrying out ground-air transient electromagnetic measurement at different flight height positions to obtain a transient electromagnetic data total set; preprocessing electromagnetic data in the transient electromagnetic data set to obtain preprocessed data; data interpretation is carried out on the preprocessed data, an underground electrical structure is reconstructed by using an inversion algorithm, and a resistivity distribution image of the underground geologic body is obtained to identify a low-resistance abnormal region; and based on an inversion result, expressing spatial distribution and physical property parameters of the deep geologic body by adopting a three-dimensional modeling technology. According to the invention, the deep geological target body can be accurately explored, so that the accurate and detailed geological information of the deep geological target body can be obtained.

The invention discloses a multi-scale loess foundation stability prediction method and system, a storage medium and equipment, and belongs to the technical field of geophysics and hydrogeology, and the method mainly comprises the steps that a high-density electrical method is used for collecting resistivity data of a loess foundation in a monitoring area; performing inversion on the resistivity data in different time periods to obtain different inversion profiles; gridding the resistivity data of the loess foundation in the monitoring area, comparing the difference of resistivity distribution among different inversion profiles, and screening out a high-risk area; and performing kernel density estimation and distribution difference analysis according to the screened high-risk area to obtain a low-resistivity data change trend, and predicting the collapse risk according to the low-resistivity data change trend by combining a multi-scale breakpoint detection technology. Based on the high-density electrical method, various data analysis technologies are combined, and efficient, economical and sustainable loess foundation stability monitoring and prediction are achieved.

The invention provides an early warning system and method for a radial artery compression hemostat based on multiple sensors, and belongs to the technical field of complication early warning. The method comprises the steps that S1, multiple types of physiological signals of a radial artery compression area are synchronously collected and subjected to digital processing; s2, discrete wavelet transform is carried out on the proximal end temperature and the telecentric end temperature; performing time domain analysis on the pulse signal, and extracting to obtain pulse amplitude; s3, constructing a temperature distribution model of the compression area based on the temperature difference signal; s4, the resistivity distribution of the compression area is reconstructed through the electrode impedance signal, and the errhysis position is positioned; s5, calculating a pressure change rate based on the pressure digital signal; calculating a pulse amplitude attenuation rate based on the pulse amplitude; and fusing the pressure change rate, the temperature gradient vector, the pulse amplitude attenuation rate and the errhysis index through a weighted summation formula to obtain a comprehensive risk value. According to the invention, through multiple types of sensors, the complication related parameter coverage rate is improved, and the complication early warning timeliness and accuracy are improved.

The invention relates to the technical field of data processing, discloses an earth and rockfill dam leakage positioning method based on joint inversion and data fusion, and aims to solve the problems of limitation and non-uniqueness of an existing single geophysical prospecting method in leakage hidden danger positioning. Converting the first apparent resistivity into a first apparent resistivity; second apparent resistivity distribution of the earth-rock dam is obtained through a high-density electrical method; acquiring electromagnetic wave velocity distribution by adopting a ground penetrating radar method, and converting the electromagnetic wave velocity distribution into third apparent resistivity; performing data standardization processing on the apparent resistivity to obtain standardized apparent resistivity data; performing dimension reduction fusion on the standardized apparent resistivity data corresponding to each apparent resistivity by adopting a principal component analysis method to obtain simulated apparent resistivity distribution; and determining the position of the leakage hidden danger channel in the earth-rock dam based on the pseudo-apparent resistivity distribution. The method improves objectivity, accuracy and reliability of leakage positioning, and is particularly suitable for danger removal and reinforcement of earth and rockfill dams.

The invention relates to the field of geophysical electromagnetic exploration, and provides a time-frequency electromagnetic data processing method, device, equipment and medium, and the method comprises the steps: calculating the similarity offset ratio of each measuring point on a measuring line, and determining a static displacement measuring point on the measuring line based on the similarity offset ratio; calculating equivalent apparent resistivity ratio of static displacement measurement point based on equivalent apparent resistivity of electric field component and corrected equivalent apparent resistivity of magnetic field component corresponding to adjacent measurement points on left and right sides of static displacement measurement point, and updating equivalence of electric field component of static displacement measurement point based on equivalent apparent resistivity ratio and corrected equivalent apparent resistivity of magnetic field component apparent resistivity; and completing static displacement correction in response to the static displacement measuring points on the measuring line, and performing inversion calculation on the magnetic field component amplitude and the electric field component amplitude of each measuring point on the measuring line to obtain resistivity distribution of a preset depth below the measuring line. The scheme disclosed by the invention is beneficial to improving the exploration and prediction precision of the time-frequency electromagnetic oil and gas target.

The invention discloses a deep geological anomalous body identification method based on transient electromagnetic and muon detection, which comprises the following steps of: respectively carrying out transient electromagnetic detection and muon detection on a region needing to be detected, and processing data obtained by the transient electromagnetic detection to obtain resistivity distribution data of the region needing to be detected; meanwhile, processing data obtained by muon detection to obtain density distribution data of the area needing to be detected; joint inversion is carried out on the data of the two physical properties through a cross gradient algorithm based on discrete smooth interpolation constraint, and the advantage of a cross gradient function does not depend on a relational expression between the physical properties, but inversion is carried out through the similarity of the underground structure; the discrete smooth interpolation algorithm performs smooth constraint on the inversion result of the cross gradient function, so that the influence of local oscillation and noise can be suppressed to a certain extent, the precision of the final inversion result is higher, and accurate identification of density anomaly and resistivity anomaly in the area needing to be detected is realized.

The invention belongs to the technical field of mine geophysical prospecting, and particularly relates to a three-dimensional direct current method roadway hole combined detection method and system. Firstly, a target drill hole and a roadway measuring line are combined to design a three-dimensional long measuring line; constructing a three-dimensional geologic model and establishing a space coordinate system according to the three-dimensional long measuring line, the mine laneway and the space structure of the stope face, installing an instrument and an electrode in the three-dimensional long measuring line, performing pole shifting to acquire voltage and current data, and calculating apparent resistivity data of the stope face of the mine laneway according to the acquired voltage and current data; performing three-dimensional resistivity inversion fitting calculation on the apparent resistivity data to generate an inversion three-dimensional resistivity data volume; and finally, the inversion three-dimensional resistivity data volume is analyzed, resistivity distribution conditions in different time periods are obtained, and the migration change condition of the water body of the stope face is speculated according to the change condition of the resistivity distribution along with time. The problem that a mine direct current electric method in the prior art still lacks the accuracy of water disaster abnormity monitoring can be solved.

The invention provides a coal rock resistivity dynamic real-time testing device and method in a water injection process, the device comprises a measuring electrode, a resistivity measuring system, a data acquisition system and a data processing system, the measuring electrode is used for forming an electrode network and is in contact with coal rock, and the resistivity measuring system is used for measuring the resistivity of the coal rock. The resistivity measurement system is used for measuring the resistivity of the coal rock; the data acquisition system is used for acquiring resistivity data in real time; and the data processing system is used for carrying out inversion processing on the collected resistivity data to obtain a resistivity distribution image in the coal rock. According to the invention, continuous or quasi-continuous resistivity measurement is carried out on a water injection area by arranging a specific electrode array according to the change rule of the resistivity of the coal rock along with factors such as moisture content, pore structure and ion migration in the water injection process, and the resistivity of the water injection area is measured through a data acquisition and processing system. The water injection state, the permeation path and the wetting effect in the coal rock are dynamically reflected in real time, and a scientific basis is provided for real-time adjustment and optimization of water injection parameters.

The invention provides an equivalent circuit analysis method and system for soil resistance heating efficiency, and relates to the technical field of soil remediation. Resistivity distribution data and salt content distribution data of a pile space are obtained; calculating the ionic conductivity according to the salt content distribution data, and calculating the target conductivity of each grid unit; constructing a topological graph, and constructing a weighted adjacent matrix based on the topological graph; constructing a degree matrix according to the degree of each graph node to obtain a feature value sequence and a feature vector corresponding to each feature value; extracting a second small feature value from the feature value sequence as a connectivity index, and marking a mutation position as a weak connection interface; the blocking factor is determined by counting the number of graph nodes located at the weak connection interface, the equivalent circuit transmission efficiency representing the soil resistance heating efficiency is calculated based on the negative correlation between the connectivity index and the blocking factor, and accurate quantitative evaluation of the heterogeneous soil resistance heating efficiency is achieved.

The invention provides a floating photovoltaic power station grounding resistor fault positioning method and device, the method is applied to a controller in a fault positioning system, and the fault positioning system further comprises a grounding grid of a floating photovoltaic power station, a sensing network formed by deploying sensors at key nodes of the grounding grid, and a signal generator. The method comprises the following steps: in response to a received fault positioning instruction, triggering a signal generator to inject a high-frequency test current signal into a grounding grid; acquiring a current-voltage data set through a voltage response signal of each key node acquired by a sensing network; based on the current-voltage data set, resistivity distribution reconstruction is carried out by adopting an impedance imaging algorithm, and a three-dimensional resistivity distribution diagram of the grounding grid is generated; and according to the three-dimensional resistivity distribution diagram, positioning an abnormal region with a resistance value exceeding a preset threshold value in the grounding grid. According to the method, three-dimensional visual imaging of resistivity distribution in the grounding grid and accurate positioning of an abnormal area are realized.

The present application belongs to the technical field of semiconductor device performance testing, and particularly relates to a VCSEL epitaxial wafer resistivity distribution measurement method and system, which comprises the following steps: constructing a three-dimensional discretization model representing the epitaxial wafer and an unknown parameter vector containing a vertical resistivity, a top lateral resistivity and a nonlinear resistance of a substrate leakage junction; defining a physical response function, and through a discrete point fitting algorithm, iterating the vector to minimize the total residual between the simulated voltage difference output by the function and the measured voltage value under a cross order of magnitude current, and extracting the real vertical resistivity from the optimal parameter vector; and obtaining the vertical resistivity of each point on a two-dimensional test point grid to generate a distribution map and perform anomaly detection. The present application solves the measurement distortion problem caused by substrate leakage defects and improves the measurement accuracy of the vertical resistivity.

The application discloses a brain injury identification method and an identification system. The identification system identifies the injury of a patient according to the identification method. The identification method comprises the following steps: firstly, the electrical impedance tomography (EIT) of the brain of the patient is performed to obtain the EIT image of the brain of the patient; then, the region with abnormal resistivity distribution in the EIT image of the brain is taken as a reference for scanning of a near-infrared spectrometer, and a scanning path of the near-infrared spectrometer is planned; finally, the near-infrared spectrometer is scanned along the scanning path, and the lesion range and the lesion type are determined according to the obtained near-infrared spectral data. The electrodes need not be arranged on the whole head of the patient, and the automatic and rapid identification of the lesion range and the nature of the brain injury is realized.

The invention discloses a method for improving resistivity distribution uniformity of a single crystal silicon rod, and belongs to the technical field of photovoltaic material production, and the method comprises the following steps: (1) preparing a multi-element master alloy which comprises a ternary master alloy or a quaternary master alloy and the like; (2) calculating the doping concentration of the multi-element mother alloy in the silicon raw material according to the target monocrystalline silicon rod parameter, wherein the target monocrystalline silicon rod parameter comprises the resistivity rho of the head of the target monocrystalline silicon rod; and (3) feeding the silicon raw material and the multi-element master alloy according to the calculated doping concentration of the multi-element master alloy, and preparing the silicon single crystal rod with good resistivity distribution uniformity by using a multi-feeding and multi-pulling method. Besides, a second movable auxiliary chamber is further arranged in a conventional single crystal furnace device, after drawing of the single crystal rod is completed in the main heating chamber, the next cooling process is performed in the first auxiliary chamber and the second movable auxiliary chamber in sequence, the heat preservation waiting time of the main heating chamber is shortened, and the crystal pulling efficiency is improved.

The application provides a kind of early warning system and method of radial artery compression hemostat based on multiple sensors, belongs to complication early warning technical field.The method comprises the following steps: S1, multiple types of physiological signals in the radial artery compression area are synchronously collected and digitized;S2, the temperature at the proximal end and the temperature at the distal end are subjected to discrete wavelet transform;the pulse signal is subjected to time domain analysis, and the pulse amplitude is extracted;S3, a temperature distribution model of the compression area is constructed based on the temperature difference signal;S4, the resistivity distribution of the compression area is reconstructed through the electrode impedance signal, and the bleeding position is located;S5, the pressure change rate is calculated based on the pressure digital signal;the pulse amplitude attenuation rate is calculated based on the pulse amplitude;the pressure change rate, the temperature gradient vector, the pulse amplitude attenuation rate and the bleeding index are fused through a weighted summation formula, and a comprehensive risk value is obtained.The application improves the complication-related parameter coverage rate through multiple sensors, and improves the timeliness and accuracy of complication early warning.

This application provides an automatic silicon core testing device, relating to the field of polysilicon technology. It includes: a positioning mechanism for positioning at least one silicon core, the silicon core being arranged laterally or vertically and capable of rotating about its own axis; a size measuring mechanism for measuring the dimensions of the silicon core; a resistivity measuring mechanism for measuring the resistivity distribution of the silicon core; and a driving mechanism for contacting or separating the resistivity measuring mechanism from the silicon core. This automatic silicon core testing device solves the technical problem that current silicon core testing mainly relies on manual sampling, which suffers from low efficiency, high missed detection rate, large human measurement errors, and the possibility of substandard silicon cores being used despite passing sampling. This leads to substandard silicon cores entering the production process and even causing serious accidents such as furnace collapse and silicon core detachment, resulting in huge economic losses.

The invention relates to the technical field of nondestructive testing of geotechnical engineering anchoring structures, in particular to an anchor cable grouting quality detection method based on electrical resistance tomography, which comprises the following steps: establishing a refined electrical simulation model, performing differential insulation parameter optimization design on a free section and an anchoring section of an anchor cable, and effectively inhibiting current shunt; optimizing the spatial arrangement of the electrode array based on targets such as the signal-to-noise ratio and the sensitivity field uniformity; in an inversion algorithm, the steel strand and an insulating layer are used as prior constraints, and the dynamic identification capability is improved in combination with time sequence regularization; and finally, performing intelligent comparative analysis on the resistivity distribution obtained by inversion and a pre-constructed grouting body resistivity characteristic reference library, and outputting a quantitative test result and a visual image containing defect positions, types, sizes and overall quality grades. According to the invention, high-precision, three-dimensional and quantitative nondestructive testing and dynamic monitoring of the grouting quality of the anchor cable are realized.

The present application discloses a method for testing the resistivity of a conductive silicon carbide wafer after cutting, which belongs to the technical field of silicon carbide wafers, and includes the following steps: a. Segmented cleaning: placing the cut silicon carbide wafer in a basket, and sequentially soaking it in an acid-base tank containing an organic solvent, an acid or alkali solution, and water, and ultrasonicating it in an organic solvent after cleaning, and drying it; b. Using an FRT surface tester, testing the thickness of multiple points on the surface of the wafer, and finally obtaining the average value of the thickness data; c. Using a non-contact resistivity tester, inputting the average thickness of the wafer, setting the test points according to the point distribution, and testing the probe twice at each point during the test, and finally drawing a resistivity distribution map of the entire wafer surface, and statistically calculating the maximum value, minimum value, and average value. The present application uses a limited type of solution for cleaning, advances the resistivity test to before grinding, and saves costs; matching a specific point distribution provides an accurate basis for judging the quality of the wafer.

A method for evaluating a silicon single-crystal ingot is provided that reduces the time required to evaluate the resistivity variation in the crystal length direction and improves wafer yield. In the method for evaluating a silicon single-crystal ingot according to the present embodiment, a counter doping is performed by adding a sub-dopant during the pulling of silicon single-crystals ingot by the CZ method, resistivity on a side surface in a crystal length direction is measured by a four-point probe method in a silicon single-crystal ingot 1 state after the silicon single-crystal ingot is pulled up, and a reject range is determined on the basis of a resistivity distribution in the crystal length direction.

The application discloses a GaN high-resistance layer preparation method and a GaN HEMT device preparation method. The GaN high-resistance layer preparation method is prepared by a MOCVD device and comprises at least one substrate layer, and a GaN high-resistance layer is epitaxially grown based on the substrate layer. The substrate layer at least comprises a pretreatment stage of nucleation and / or epitaxial growth. A Ga source in a reaction gas used when the substrate layer is pretreated is TMGa. When the GaN high-resistance layer is prepared, a C source for doping is independently supplied, and the Ga source in the reaction gas is switched to TEGa. The growth temperature is 900-1100 DEG C. Under the growth temperature, TEGa is less likely to decompose active C atoms beneficial to Ga-C bond formation than TMGa, so as to avoid that the concentration distribution of the C source available for doping is affected by the decomposition reaction of the Ga source. The high-resistance layer provided by the application has a uniform resistivity distribution.

The invention discloses a CO2 storage area intelligent monitoring method based on multi-source data combination, and the method comprises the steps: obtaining a hyperspectral image of a CO2 storage area through the macroscopic monitoring of the hyperspectral image, and extracting a spectral index which is high in CO2 sensitivity and correlation; the method comprises the following steps: inverting underground resistivity distribution of a CO2 sequestration area through a high-density electrical method, then measuring carbonate contents in soil at different positions, respectively determining a relationship between the carbonate contents and spectral indexes to establish a spectram-CO2 sequestration correlation model, determining a relationship between the carbonate contents and resistivity, and establishing a resistivity-CO2 sequestration correlation model; and finally, fusing various parameter data to construct a random forest joint monitoring model, and realizing CO2 storage area leakage prediction. According to the method, single data dimension limitation is broken through through spectrum-electrical characteristic coupling, monitoring of the full-area storage state of the CO2 storage area from the earth surface to the deep part is achieved, long-term stability of the CO2 storage area is guaranteed, and technical support is provided for safe implementation of coal mine carbon waste storage engineering.