183 results about "Magnetic susceptibility" patented technology

The invention relates to the technical field of geophysics, and particularly discloses a comprehensive inversion method and system based on bidirectional magnetic susceptibility weighted constraint, and the method comprises the steps: dividing an underground three-dimensional space, and building two different cuboid models; determining a total magnetic field observed on the ground and gradient anomaly thereof based on the observation point coordinates and the cuboid model position, and establishing a kernel function matrix; determining an inversion objective function reflecting the relationship between the total magnetic field and the gradient anomaly thereof and the physical property parameters; adding the bidirectional magnetic susceptibility weighted constraint function into an inversion objective function; the optimal solution of the comprehensive inversion target function is solved based on the conjugate gradient method, the high-level resolution capability of the magnetic gradient data and the deep detection advantage of the total magnetic field data are fused, the precision of fine depiction of the superficial anomalous body boundary and the reconstruction precision of the deep field source structure are remarkably improved, a vector cross multiplication regularization constraint mechanism is introduced, and the method has the advantages of high resolution and high resolution. The inversion multiplicity under the complex geological condition is greatly inhibited, and the reliability of the model result and the geological rationality are enhanced.

The invention relates to the technical field of general image data processing or generation, in particular to a collaborative detection method for ore concentration area transparency, which is executed by a processor and comprises the following steps: acquiring a gravity data set, a magnetic method data set and an electrical method data set; executing structural consistency joint inversion on the gravity data set, the magnetic method data set and the electrical method data set under the constraint of physical constraint information to form an initial model; forming an optimization model; executing hybrid joint inversion on the optimization model under the constraint of physical constraint information to obtain wave velocity distribution data, resistivity distribution data, density distribution data and magnetic susceptibility distribution data; constructing a three-dimensional geology-geophysical model and performing forward modeling calculation on the model; and an optimal three-dimensional geology-geophysics model is obtained. According to the method and the device, the problems that in the process of realizing the transparency of the ore concentration area, the existing joint inversion cannot meet the requirement of realizing the transparency of the ore concentration area on underground high-precision physical property distribution and the modeling precision is low are solved.

The invention discloses a nuclear magnetic T2 spectrum correction method for a shale reservoir, and relates to the field of object detection, and the nuclear magnetic T2 spectrum correction method for the shale reservoir comprises the following steps: 1, determining the gas logging porosity, saturated water porosity and main mineral components of the shale reservoir; compared with the prior art, the method disclosed by the invention has the beneficial effects that a drying-saturated water-centrifugal two-dimensional nuclear magnetic resonance experiment is carried out, and signals of crystal water, clay bound water and hydroxyl in a sample are preliminarily identified; through inversion of organic matter signals in the dry sample, signals of movable water are further determined; the relation between the difference value among the gas logging porosity, the saturated water porosity and the nuclear magnetic porosity and different mineral contents is discussed, and particularly the remarkable influence of iron-containing minerals on the porosity difference value is discussed; by eliminating the influence of diffusion relaxation caused by the magnetic susceptibility difference, the T2 spectrum correction method based on the mineral magnetic susceptibility is established, and the T2 spectrum accuracy obtained through nuclear magnetic resonance measurement is improved.

The invention relates to an active source magnetization-time domain electromagnetic induction polarization multi-parameter extraction method, and provides an active source magnetization-time domain electromagnetic induction polarization multi-parameter extraction method aiming at induction response caused by conductivity, polarization response caused by chargeable property and magnetization response caused by magnetic complex physical property in polymetallic ore detection. When the emission current is in a flat-topped stage, based on an active magnetic method, magnetic susceptibility extraction is carried out by using an Oxim method; when the emission current is in a turn-off stage, resistivity and polarization extraction is carried out by using a depth Q network method based on a time domain electromagnetic method by taking the extracted magnetic susceptibility as a constraint condition; and finally, multi-parameter extraction of resistivity, polarizability and magnetic susceptibility of the active source magnetization-time domain electromagnetic induction polarization method is realized.

The invention relates to the technical field of magnetic exploration, in particular to a deep learning network structure and method for magnetic anomaly inversion, and solves the problems that a traditional linear inversion method is slow in calculation stable speed and relatively low in precision, and a traditional ground and aeromagnetic data inversion method is insufficient in vertical resolution and relatively low in precision. A traditional linear inversion method is always encountered with the problems of low calculation efficiency and poor stability due to the local minimum value problem, and comprises an inversion network encoder, and a residual block and down-sampling method is adopted to realize the characteristics of magnetic anomaly data to extract an encoding network unit in a two-dimensional form. According to the method, feature extraction of magnetic anomaly data is realized, a residual module is added in an encoder to fuse feature maps from different sources, a three-dimensional magnetic susceptibility structure is reconstructed from two-dimensional observation magnetic field data, and in order to solve the problem that a sample library of deep learning inversion needs enough diversity and complexity, the method has high robustness. The generalization ability of the magnetic method inversion neural network is fully improved, and the inversion precision is further improved.

In various embodiments of the invention, a cooled nuclear magnetic resonance (NMR) probe can utilize a sliding band capacitor which can be moved relative to a parent coil inner conductance tapered skirt to adjust the frequency of the parent coil to allow the parent coil to detect the resonance of at least two nuclei without requiring leads between the parent coil and a lock coil. In this manner a cooled NMR probe can be provided without the disadvantages of prior art cooled NMR probes. In an embodiment of the invention, the sliding band capacitor comprises a diamagnetic insulator with a first volume magnetic susceptibility, at least one paramagnetic metal with a second volume magnetic susceptibility and at least one diamagnetic metal with a third volume magnetic susceptibility, where the sum of the first volume magnetic susceptibility, the second volume magnetic susceptibility and the third volume magnetic susceptibility is approximately zero.

The present invention relates to a magnetic susceptibility inversion method and system, the method comprising: S1, obtaining a spatial domain residual based on observed magnetic field intensity and theoretical magnetic field intensity; S2, expressing the spatial domain residual by two-dimensional discrete Fourier inverse transform based on wave number domain residual; S3, obtaining a wave number domain model perturbation based on the spatial domain residual, and further obtaining a spatial domain model perturbation based on Fourier inverse transform; S4, obtaining a magnetic susceptibility inversion model based on the spatial domain model perturbation. The present invention reduces the required memory space, improves the calculation efficiency, and further improves the inversion efficiency.

The invention relates to the technical field of chromatographic detection and material characteristic analysis, and discloses a multiphase chromatographic analysis system and method.The multiphase chromatographic analysis system comprises a multiphase sample injection module, a multi-field cooperative regulation and control separation column module and a plurality of separation chromatographic columns which are sequentially connected, and the separation chromatographic columns comprise partitions and are installed in a column box in an end-to-end connection mode; a temperature gradient field, an electric field gradient field, a controllable electromagnetic field and a fluid power field; and a multi-modal detection module, a data acquisition and control module and an auxiliary module. Through the brand-new multi-phase sample injection module, the multi-field coordinated regulation and control separation column module and the multi-mode detection module, direct input of detected objects in different phase states can be met, and phase state conversion is carried out according to needs, so that the phase state compatibility of the analysis system to the detected objects is obviously enhanced; and different components can be obviously separated according to different boiling points, migration speeds and magnetic susceptibilities by combining multi-field synergistic separation, so that the chromatogram is more accurate.

A system for controlling a translocation speed of a molecule through a nanopore may include a fluid chamber containing a solution with a magnetic susceptibility that is different from the magnetic susceptibility of the molecule, a nanopore situated in the fluid chamber, and at least one magnetic component configured to create a magnetic field gradient within the solution to control the translocation speed of a molecule through the nanopore. A system for controlling a translocation speed of a molecule through a nanopore may include a nanopore at least one magnetic component situated to create a magnetic field that causes the molecule to experience a rotational torque as it passes through the nanopore.

The invention relates to the technical field of marine geological resource exploration, in particular to a rapid seabed heavy placer detection method based on shipborne pull-type combined measurement, which comprises the following steps: S1, connecting a pull body integrating a gamma-ray spectrum detection assembly, a magnetic susceptibility detection assembly and a pressure-bearing sealing structure with a shipborne integrated control host through a cable; s2, acquiring gamma-ray spectrum data and sediment magnetic susceptibility; s3, performing water depth pressure compensation correction on the gamma-ray spectrum data, and performing inclination angle correction on the magnetic susceptibility data; s4, converting the corrected gamma-ray spectrum data into a radioactivity abnormal intensity graph, and converting the corrected magnetic susceptibility data into a magnetic susceptibility abnormal intensity graph; and S5, spatial superposition is carried out, and a heavy placer target area is screened out. According to the method, through integration of a multi-parameter detection and correction mechanism, accurate identification and standardized output of the seabed heavy placer abnormal region are realized, and the reliability and the judgment efficiency of near-bottom layer resource detection are remarkably improved.

The invention discloses a slope monitoring method and system based on an unmanned aerial vehicle, and relates to the technical field of intelligent geological disaster monitoring, and the method comprises the steps: carrying a magnetic gradient measurement unit and a laser radar through the unmanned aerial vehicle, and collecting magnetic gradient tensor collection and slope surface point cloud from multiple heights and multiple routes; on the basis of a gradient adaptive weighted total variation inversion method, slope gradient information extracted by a digital elevation model is introduced into regularization weight adjustment, so that an inversion result can be adaptively adjusted in different gradient areas; based on a magnetic susceptibility distribution model, a magnetic construction adaptive clustering and risk index calculation method is used, and through amplitude density index and gradient constraint search, clustering identification and risk quantitative partitioning of a high-gradient accumulation area are carried out. Therefore, expansion from surface slope deformation monitoring to deep concealed structure detection is realized, and concealed slip zones or fissure zones can be accurately revealed under complex terrain conditions.

A method for evaluating geological hydrogen source rock in a region is provided. The method includes: collecting magnetic susceptibility data from a plurality of subsurface locations in the region; receiving geophysical survey data of the region, wherein the geophysical survey data comprises geophysical data collected from above ground; tying the magnetic susceptibility data of the plurality of subsurface locations to the geophysical survey data; generating a geologic map of igneous rock, metamorphic rock, or mafic mineral- or iron-rich sedimentary rock within the region based on the magnetic susceptibility data using a model; and determining, based on the geologic map, a target zone of the geological hydrogen source rock with a potential for hydrogen production or with the potential for hydrogen accumulation.

The invention relates to the technical field of iron ore detection, and discloses a deep coverage area skarn type iron-rich ore target detection method based on gravity and magnetic data. The method comprises the steps of collecting and preprocessing gravity and magnetic measurement data of a target area to obtain a standardized gravity and magnetic data set; based on the geological background of the analysis area, the structure and lithology distribution characteristics are extracted, and the metallogenic conditions are matched to screen the potential metallogenic target area. And performing multi-scale decomposition on the gravity and magnetic data of the target region, obtaining different depth level abnormal features, constructing a three-dimensional geologic structure model, and obtaining density and magnetic susceptibility distribution based on model inversion. Accordingly, the ore body is recognized, spatial distribution features are extracted, continuity and scale of the ore body are determined through spatial correlation analysis, and a final prediction result is output after geological constraint condition optimization is combined. The method is suitable for a complex environment with signal shielding and abnormal superposition in a deep coverage area, deep ore body information can be accurately captured, and a feasible path is provided for skarn type rich iron ore detection.

The invention discloses a quantitative magnetic susceptibility imaging accelerated scanning method based on short gradient echoes, and belongs to the field of medical image scanning, and the method comprises the steps: designing scanning parameters suitable for short echo data; constructing a de-noising diffusion probability model comprising a forward noise adding process and a reverse de-noising process, wherein a wavelet transform module is embedded in the reverse de-noising process; extracting short echo data from full echo data of the multi-gradient echo sequence, and training the de-noising diffusion probability model based on the short echo data to obtain a trained de-noising diffusion probability model; configuring the scanning parameters in a magnetic resonance imaging system; acquiring short echo quantitative magnetic susceptibility imaging data based on the configured scanning parameters; and inputting the acquired short echo quantitative magnetic susceptibility imaging data into the trained denoising diffusion probability model, and reconstructing a quantitative magnetic susceptibility image. According to the method, through scanning parameter setting and deep learning model optimization reconstruction, the existing quantitative magnetic susceptibility reconstruction scanning time can be greatly reduced, and the image quality is kept consistent.

A system for controlling a translocation speed of a molecule through a nanopore may include a fluid chamber containing a solution with a magnetic susceptibility that is different from the magnetic susceptibility of the molecule, a nanopore situated in the fluid chamber, and at least one magnetic component configured to create a magnetic field gradient within the solution to control the translocation speed of a molecule through the nanopore. A system for controlling a translocation speed of a molecule through a nanopore may include a nanopore at least one magnetic component situated to create a magnetic field that causes the molecule to experience a rotational torque as it passes through the nanopore.

The invention discloses a grey matter brain region anti-magnetic component susceptibility map construction and analysis method and application thereof, which can be used for exploring a global distribution mode of cortical iron deposition of an AD patient on a voxel level and positioning a cortical region with susceptibility related to cognition. The method comprises the following steps: (1) carrying out MR data acquisition on a subject on a magnetic resonance scanner; (2) unwrapping the multi-echo phase image by using a phase unwrapping method based on Laplacian; performing brain stripping processing on the amplitude image of the first echo by using a BET algorithm built in FSL software and generating a binary brain mask image; removing a background field of the unwound phase diagram by using a V-SHARP algorithm in combination with the brain mask diagram; calculating a magnetic susceptibility map from the local field map by using an STAR-QSM algorithm; (3) calculating the cortex thickness by using the T1 weighted structure image, and performing post-processing on the 3D-FSPGR sequence structure image; and (4) carrying out voxel-based whole-brain QSM analysis and cortex thickness statistical analysis.

The invention discloses a gravity and magnetic data multi-scale fusion processing method based on physical property parameter joint inversion, and the method comprises the steps: collecting gravity and magnetic data of a target region, carrying out the preprocessing of the gravity and magnetic data, and obtaining the preprocessed gravity and magnetic data; for the superimposed volume effect of different-scale field source bodies of the gravity magnetic field in the target area, decomposing the preprocessed gravity magnetic data into different scales by adopting wavelet transform to obtain multi-scale gravity magnetic data; according to the physical property correlation model of the density and the magnetic susceptibility in the research area range, constructing a joint inversion objective function, and in combination with the joint inversion objective function, performing physical property joint inversion on the gravity and magnetic data of multiple scales on different scales to obtain a density three-dimensional data body and a magnetic susceptibility three-dimensional data body; and carrying out weighted fusion on the density three-dimensional data volume and the magnetic susceptibility three-dimensional data volume. According to the method, the abnormal body positioning precision and the deep structure identification capability are improved, and a reliable technical means is provided for resource exploration under complex geological conditions.

The linear measuring system includes one part of a (usually steel) rod, beam or strip that is profiled with a trapezium like (subset of a) De Bruijn sequence. Each element of the alphabet is represented by a discrete height of the profile. The profile can be coated with a material with low magnetic susceptibility to enable the application on a piston rod of a pressure medium cylinder. The second part of the measuring system reads the subsequences of the main sequence by using the signals of arrays of linear Hall effect sensors, placed in a magnetic field as input for a signal processing algorithm. With a look-up table, the position of this second part of the measuring system with respect to the profile is determined. An interpolation algorithm can be used to improve the resolution to well below the sequence pitch.

The fusion adaptive dynamic prior information magnetotelluric and magnetic method joint inversion method belongs to the field of geophysical data processing and inversion technology; by constructing a joint inversion objective function including data fitting term, model constraint term and physical coupling term, and using Gauss-Newton method for solving, the core innovation lies in introducing adaptive dynamic prior information extraction technology; the method can automatically generate and optimize prior constraints from data itself and intermediate results, without relying on external preset information, thereby significantly improving the accuracy and reliability of the boundary description and physical property recovery of underground abnormal bodies (such as resistivity, magnetic susceptibility anomaly); solve the problem that the traditional physical property coupling joint inversion technology has strong dependence on prior information and weak application generalization ability in information missing area.

A magnetic resonance imaging device (100) according to the present invention comprises a sequence control unit (120), a first calculation unit (150d), a range selection unit (150h), a second calculation unit (150e), and a display control unit (150c). The sequence control unit (120) executes a pulse sequence and collects data from an imaging target. On the basis of the data, the first calculation unit (150d) calculates a first map indicating an amount corresponding to volume magnetic susceptibility. On the basis of an echo time (TE) value and a phase change value of the first map, the range selection unit (150h) determines a selection range for a phase slope value. On the basis of the first map and the selection range, the second calculation unit (150e) calculates a second map indicating a feature amount of a voxel value of the first map or a region of a part of the first map. The display control unit (150c) displays an image on a display unit on the basis of the second map.

The present invention discloses a rare earth permanent magnet material, its preparation method and application. The average particle size of the main phase grains of the rare earth permanent magnet material is 5 to 10 μm; the particle size distribution ratio of the main phase grains of the rare earth permanent magnet material conforms to the curve distribution law. The average particle size of the main phase grains of the rare earth permanent magnet material in the present invention is relatively large, and it can ensure high coercive force while improving the magnetization characteristics of the rare earth permanent magnet material; the rare earth permanent magnet material in the present invention can achieve a magnetic susceptibility of more than 95% when the external magnetic field is greater than 20 kOe; and after the magnetic susceptibility reaches more than 93%, the slope of the curve of the external magnetic field and the magnetic susceptibility is large, the magnetic susceptibility growth rate is fast, and the "step-like" curve can be eliminated; the thermal demagnetization rate at 120°C can reach more than 98%.

The present invention provides a tunnel magnetoresistor, a method for manufacturing the same, and a tunnel magnetic device. The tunnel magnetoresistor comprises: a pinned layer; a free layer disposed opposite the pinned layer, the free layer being a superparamagnetic layer with a thickness less than or equal to a critical thickness; a tunnel barrier layer located between the pinned layer and the free layer; and an underlying conductive structure located on the side of the free layer facing away from the tunnel barrier layer. The free layer in the tunnel magnetoresistor is a superparamagnetic layer with a thickness less than or equal to the critical thickness. During magnetization, the magnetic moments of the single-domain particles constituting the superparamagnetic layer can be oriented in the same direction to achieve magnetic saturation, resulting in a high magnetic susceptibility. Therefore, the tunnel magnetoresistor provided by the present invention has a large saturation field and high linearity.

The application discloses a kind of low field intensity magnetic susceptibility weighted imaging optimization method and system, it is related to magnetic susceptibility weighted imaging field, comprising: obtaining the K space original data obtained by scanning target object;According to K space original data reconstruction image field data, extract the amplitude data and phase data of image field data;Phase data is preliminary unwrapping processing, and unwrapping phase data is obtained;Unwrapping phase data is separated from background field, and local phase diagram is obtained;Local phase diagram and amplitude data are operated based on complex domain phase separation high-pass filter, and high-frequency phase data is obtained;According to high-frequency phase data and amplitude data, the reconstruction of magnetic susceptibility weighted image is carried out, and the magnetic susceptibility weighted image of target object is obtained.The application can significantly reduce the phase artifact of SWI image, and improve the definition of image detail.

The present invention discloses a temperature measurement method under a complex excitation magnetic field of a two-dimensional magnetic nanoparticle imaging device, belonging to the field of nanomaterial testing technology. A magnetic nanometer temperature measurement method is proposed for the complex excitation magnetic field generated by the two-dimensional magnetic nanoparticle imaging device. Specifically, while utilizing the complex excitation signal to cause the magnetic nanoparticles to have a rich relationship between nonlinear magnetic susceptibility and temperature, the method also considers the influence of field strength and particle saturation magnetization on temperature measurement in actual two-dimensional MPI applications, establishes a compensation function, and provides a temperature measurement model when the dominant relaxation mechanism of the particles is Neel relaxation or Brownian relaxation. This realizes real-time temperature detection of magnetic nanoparticles on the two-dimensional magnetic nanoparticle imaging device, solving the problem that the current magnetic nanoparticle temperature measurement method cannot accurately measure temperature under the complex excitation magnetic field of the two-dimensional magnetic nanoparticle imaging device.

The invention relates to the technical field of magnetic resonance, in particular to a magnetic resonance coil device, a using method thereof and a liquid container used for magnetic resonance scanning imaging. The magnetic resonance coil device comprises a bearing body used for bearing an examined object, and the examined object is an animal; the liquid containing space is used for containing liquid, and the detected part of the detected object is immersed in the liquid; the radio frequency coil is arranged on the outer side of the liquid containing space and used for receiving magnetic resonance signals from the detected part. According to the device, the detected part of the detected object can be subjected to magnetic resonance imaging scanning in a liquid environment instead of an air environment, so that magnetic susceptibility artifacts at the boundary position of the detected part can be inhibited, the quality of a magnetic resonance image is improved, and accurate analysis and research on the detected part are facilitated.

The invention discloses a metal mass block with near-zero magnetic susceptibility and a preparation method thereof, and belongs to the field of gravitational wave detection. The invention aims to solve the problems that the magnetic susceptibility of the existing quality inspection material is still high, and the price of the used noble metal alloy is high. The metal mass block with the near-zero magnetic susceptibility is an AuPt precious metal mass block, an AuIr precious metal mass block or a CuAl non-precious metal mass block. The preparation method comprises the following steps: 1, weighing; and 2, smelting the alloy by adopting a vacuum precision suspension smelting furnace. The invention is used for the near-zero magnetic susceptibility metal mass block and the preparation thereof.

The invention discloses a method for calculating a quantitative magnetic susceptibility image through total field inversion based on a Green function. The method is used for separating a background magnetic field and reconstructing a whole-brain quantitative magnetic susceptibility image in magnetic resonance imaging. According to the boundary element method full-field inversion method, filtering and regularization processing on tissue magnetic susceptibility are prevented from being additionally introduced when background field interference is removed, the background field can be effectively separated, a whole-brain quantitative magnetic susceptibility image can be reconstructed, the boundary erosion phenomenon cannot occur, and the boundary element method full-field inversion method particularly shows excellent performance in a cortex area. According to the method, a fast multipole method is adopted to efficiently process storage and calculation of a dense matrix generated by a boundary integral equation.

The present disclosure relates to implantable markers for imaging and surgical guidance. An implantable marker for imaging and surgical guidance by susceptibility measurement, comprising one or more pieces of ferromagnetic material having a total aspect ratio of at least about 500 and a total volume of less than about 1 x 10-11 m3. The one or more pieces of ferromagnetic material may have a high initial relative permeability (μr,i) > about 1000. Also disclosed is a detection system for locating an implantable marker, comprising such an implantable marker; at least one drive coil arranged to excite the marker with an alternating magnetic field, and at least one sensing coil arranged to detect a signal received from the excited marker; a magnetic field generator arranged to drive an alternating magnetic field through the at least one drive coil; and at least one detector arranged to receive a signal from the sensing coil and detect one or more harmonics of the drive frequency in the received signal.

The invention discloses a vertical section stratum boundary line identification method based on an aeronautical geophysical prospecting susceptibility result map, which can quickly and efficiently delineate a vertical section stratum boundary line (including stratum lithology division and fault / fracture zone boundary division) by utilizing an aeronautical geophysical prospecting susceptibility result in a tunnel engineering geological survey stage in a complex and hard mountainous area, improve the survey efficiency and reduce the construction cost. The method has the advantages of simple process, low cost and low exploration cost investment, is especially suitable for detecting target bodies with large magnetic differences or geologic bodies with components of minerals (especially biotite, hornblende, magnetite and the like) in rocks changed due to different metamorphic degrees, and can be used for detecting the content of the rock according to the magnetic susceptibility value and the abnormal distribution form and by comprehensively considering factors such as stratum lithology and drilling data. A vertical section stratum lithology boundary or a fault fracture zone boundary can be specifically divided; the method is especially applied to tunnel areas with large differences between different stratum lithology and magnetic susceptibility, and has strong identification capability.

A system and method to create a static (DC) or near static magnetic field either using permanent magnets or a transmitter loop. The field magnetizes the objects as they pass through the field and response based on the volume of the material and the magnetic susceptibility. By making measurements of the resulting magnetic field (B field or in this case dB / dt), the system can measure how magnetized the object becomes. This property can be used alone and just recover information about magnetic susceptibility, or this information can be combined with other physical properties such as permanent magnetization or other properties such as electrical conductivity.