321 results about "Magnetic field gradient" patented technology

The invention relates to the technical field of power batteries, in particular to a power battery pack health state detection method and system. The power battery pack health state detection method comprises the following steps: acquiring open-circuit voltage change data and terminal voltage fluctuation data of a battery under micro current pulse excitation, recording a change curve of voltage along with time through high-precision time sequence acquisition equipment, and obtaining an initial data set of voltage dynamic response; acquiring magnetic field intensity distribution and magnetic field gradient change data of the surface of the battery in a weak alternating magnetic field, and acquiring spatial magnetic field information through a magnetic sensor array to obtain a three-dimensional distribution diagram reflecting magnetic field nonuniformity; through a three-dimensional distribution diagram of magnetic field intensity distribution and magnetic field gradient change, a defect detection algorithm is adopted to analyze a mapping relation between magnetic field non-uniformity and internal micro cracks, and correlation distribution of defect positions and internal resistance growth rates is determined.

The invention provides an electrical equipment remote maintenance guidance method and system. The method comprises the following steps: capturing an aperiodic torque waveform and a magnetic field gradient abnormal signal by deploying a torque fluctuation sensor and a magnetoresistive sensor; performing multi-scale frequency band division on the non-periodic torque waveform, screening out a transient high-frequency component in a start-stop stage of equipment, and separating out a magnetic field polarity reversal characteristic from a magnetic field gradient abnormal signal; performing cross-domain matching on the occurrence time of the transient high-frequency component and the spatial orientation of the magnetic field polarity reversal feature to generate a mixed feature mark; calculating a frequency band overlapping degree based on the time-frequency energy distribution marked by the mixed features and generating a coherence map; and matching a fault historical case library according to the coherence map, and outputting a maintenance strategy set aiming at the rotating shaft dynamic unbalance and electromagnetic interference superposition fault. According to the invention, through fusion of torque fluctuation and magnetic field distortion collaborative analysis, the precision of mechanical and electromagnetic composite fault diagnosis of the rotating shaft is improved.

The invention belongs to the technical field of magnetic particle imaging, relates to a magnetic particle imaging reconstruction method based on a calibration magnetic field generation system matrix, and aims to solve the problems that a traditional magnetic particle imaging reconstruction method is poor in applicability in asymmetric bilateral structure magnetic particle imaging equipment (A-MPI) and cannot perform imaging in any region. The method comprises the following steps: performing grid division on an imaging area, calibrating magnetic field intensity, and obtaining magnetic field gradient distribution of each point; obtaining a theoretical system matrix according to a mathematical calculation mode; randomly moving the positions of the non-magnetic field points for scanning to obtain actually measured magnetic field gradient distribution and a system matrix, and constructing a data set; expanding the data set based on the simulation system; constructing a deep learning model, and inputting the extended data set and the measured data into the training deep learning model; and inputting a theoretical system matrix at any position, and obtaining an accurate system matrix by using the trained model. According to the invention, the system matrix at any position can be obtained under the A-MPI equipment, so that imaging at any position is realized.

The invention relates to the technical field of aluminum-based thin film preparation, and discloses an aluminum-based thin film uniform deposition system based on magnetron sputtering. The system comprises a substrate state detection module, a magnetic field dynamic regulation and control module, a sputtering power regulation module, a deposition process monitoring module and a central control terminal. The substrate state detection module collects and transmits surface flatness data of the substrate in real time, and the central control terminal carries out visual display. The magnetic field dynamic regulation and control module obtains magnetic field intensity correction through a magnetic field gradient algorithm according to the deviation value of the real-time flatness parameter and the standard parameter and sends the magnetic field intensity correction to the sputtering power regulation module. And the sputtering power adjusting module adjusts the sputtering rate of the target material accordingly. The deposition process monitoring module tracks the adjusting process, evaluates the dynamic response performance, generates a stable or fluctuation signal and sends the stable or fluctuation signal to the central control terminal, and the central control terminal triggers sound-light alarm when receiving the fluctuation signal. The system can improve the deposition uniformity and process stability of the aluminum-based thin film.

A sensor unit for detecting brain current-induced magnetic fields in an unshielded environment has a plurality of gradiometer units configured for arrangement around a head of a user. Each gradiometer unit has two magnetometers which are arranged at a fixed distance from each other. Each magnetometer has a sensor medium and is configured to detect a magnetic field strength at a measurement location by reading a spin resonance in the sensor medium depending on the magnetic field strength. The sensor unit further includes at least one excitation light source for radiating light into the sensor media of the magnetometer. The sensor unit further incudes at least one signal processing unit for determining a magnetic field gradient at a gradiometer unit as a difference of the output signals of the two magnetometers of the gradiometer unit and for detecting a time course of the magnetic field gradient.

The invention discloses an ion control method and device, an ion trap system and a related device, and belongs to the technical field of quantum information. A plurality of ions in the ion trap system are in a magnetic field with a magnetic field gradient, the magnetic field gradient enables transition frequencies of the plurality of ions to be different, and each ion is of a multi-energy-level structure. The method comprises the steps that according to the transition frequency of a plurality of first ions, the energy level of the first ions is adjusted so that the first ions irrelevant to quantum control can be transferred from a calculation space to an auxiliary space, and the energy level of the ions in the calculation space is different from the energy level of the ions in the auxiliary space; and performing quantum manipulation on the plurality of second ions in the calculation space to form a plurality of quantum bits. According to the scheme, light finding of ions is not needed, light finding of ions is not needed, multi-ion control can be achieved through global laser or microwaves, and implementation is easy. And moreover, multi-ion control can be realized by using a relatively small magnetic field gradient, and the ion control threshold is reduced.

The invention discloses an exciting current adjusting method for four-pole / eight-pole composite iron. The exciting current adjusting method comprises the following steps: establishing a two-dimensional data comparison table of coil currents of four-pole iron and eight-pole iron; performing experimental measurement to obtain a quadrupole field magnetic field gradient three-dimensional curved surface sample database and an octupole field magnetic field gradient three-dimensional curved surface sample database; performing two-dimensional interpolation on the magnetic field gradient three-dimensional curved surface sample database by using a cubic spline function; a quadrupole field magnetic field gradient plane and an octupole field magnetic field gradient plane are selected and intersect with the quadrupole field magnetic field gradient three-dimensional curved surface sample database curved surface and the octupole field magnetic field gradient three-dimensional curved surface sample database curved surface respectively, and current curves meeting the quadrupole field gradient and the octupole field gradient are obtained; and obtaining an intersection point of the two curves, and using the intersection point as a solution of the compound iron exciting current. According to the invention, based on magnetic field measurement data under a few groups of excitation currents, a large amount of excitation current debugging time is saved, and accurate adjustment of the magnetic field gradient of the composite multi-pole magnet can be realized.

The invention relates to the technical field of crane equipment health monitoring, in particular to a crane running state health monitoring system and method. A sensing data acquisition unit is used for acquiring a winding drum vibration harmonic component, a steel wire rope leakage magnetic field gradient and a pulley block real-time load; the data analysis unit performs rotating speed synchronous variational mode decomposition on the vibration component to extract resonance characteristics, performs temperature and stress double-compensation correction on a leakage magnetic field gradient, quantifies an energy entropy attenuation rate through wavelet packet decomposition, constructs a phase difference model of a load and vibration to output a slip risk phase offset, calculates a load spectrum damage cumulant, and calculates a load spectrum damage cumulant; and after the four heterogeneous features are fused, a residual life coefficient is output through a dual-channel convolution-long and short-term memory hybrid neural network, and an execution unit triggers crane speed reduction control when the residual life coefficient is lower than a threshold value, so that the problems of insufficient multi-source data fusion and lack of dynamic compensation in the traditional technology are solved, and the fault early warning accuracy is improved.

The invention discloses a residual capacity balance control method and system for an aged lithium battery, and relates to the technical field of new energy materials and devices, and the method comprises the steps: inputting quantum magnetic field response data and infrasonic wave signals into a single-chip microcomputer, carrying out the wavelet noise reduction and histogram equalization processing based on an STM32 single-chip microcomputer, and generating an acoustic-magnetic coupling feature matrix; inputting a dynamic pheromone equalization model based on the acoustic-magnetic coupling characteristic matrix, calculating a capacity difference coupling coefficient between the battery packs through an ant colony optimization algorithm, and generating a capacity redistribution path topological graph; according to the capacity redistribution path topological graph, the energy transfer direction is controlled through a bidirectional Buck-Boost circuit, and an equalizing current threshold value is dynamically adjusted based on the quantum spin resonance magnetic field gradient; according to the invention, the quantum magnetic field response data of the aged lithium battery pack and the infrasonic wave signal generated by electrolyte decomposition are collected, so that the physical and chemical states in the battery are accurately monitored.

The invention provides a liquid leakage detection method and device for a liquid cooling device, and the method comprises the steps: obtaining the fluorescence intensity and magnetic field gradient of a surface detection region of the liquid cooling device; wherein the cooling liquid of the liquid cooling device contains a fluorescent marker and a magnetic marker; based on the fluorescence intensity and the magnetic field gradient, determining whether a liquid leakage risk exists in the detection area; in response to the liquid leakage risk of the detection area, obtaining the liquid leakage probability of each grid position of the detection area based on the fluorescence intensity and the magnetic field gradient; and determining a target grid position where liquid leakage occurs in the detection area based on the liquid leakage probability. According to the technical scheme of the invention, the detection precision and detection efficiency of liquid leakage of the liquid cooling device can be improved.

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.

An array of spin qubits relies on a gradient magnetic field to ensure that the qubits are separated in frequency in order to be individually addressable. Furthermore, a strong magnetic field gradient is required to electrically drive the EDSR of the qubits. Quantum dot devices and related methods and systems that integrate magnetic materials in the gates to provide a gradient magnetic field are disclosed. Magnetic materials in different gates may be of different heights to improve frequency separation of neighboring qubits. Unlike previous approaches to quantum dot formation and manipulation, various embodiments of the quantum dot devices disclosed herein may enable improved control over magnetic fields and their gradients to realize better frequency targeting of individual qubits, help minimize adverse effects of charge noise on qubit decoherence and provide good scalability in the number of quantum dots included in the device.

The invention provides an easy-to-scale efficient biological magnetic separation system and method and application. The magnetic separation method comprises the following steps: marking a target object in a to-be-detected suspension by adopting magnetic nanoparticles, and putting the marked to-be-detected suspension into a separation container; a modularized magnet array is arranged in the separation container, the modularized magnet array is composed of permanent magnets, and the permanent magnets are assembled into the cuboid modularized magnet array; the surface of the permanent magnet is coated with a polytetrafluoroethylene coating; the modularized magnet array moves in the suspension under the control of a driving magnet arranged outside the separation container to generate a dynamic gradient magnetic field, and a target object is captured by the modularized magnet array under the action of the gradient force of the magnetic field; removing the liquid in the separation container; adding the resuspension into a separation container, and recovering a target object by physical ultrasonic washing; or adding a chemical dissociation solution into the separation container to recover the target object.

The invention discloses a magnetic circuit structure for adjusting the gradient of a magnetic field in a Hall thruster channel, relates to the technical field of Hall thrusters, and solves the problems that a krypton working medium Hall thruster is insufficient in krypton working medium ionization and low in thruster efficiency. The device comprises magnetic poles, an inner iron core, a bottom plate, a magnetic screen, an outer magnetic conductive cover, a coil and an annular channel, the inner iron core is arranged at one end of the upper surface of the bottom plate, the outer magnetic conductive cover is arranged at the other end of the upper surface of the bottom plate, and the magnetic poles are arranged at the upper ends of the inner iron core and the outer magnetic conductive cover; a magnetic screen is arranged on the bottom plate and comprises an inner magnetic screen and an outer magnetic screen, and an annular channel is arranged between the inner magnetic screen and the outer magnetic screen; a coil is arranged between the inner magnetic screen and the inner iron core, and a coil is arranged between the outer magnetic screen and the outer magnetic conductive cover; and grooves are formed in the inner magnetic screen and the outer magnetic screen. By adjusting the thicknesses of different positions of the magnetic screen, the magnetic flux density is saturated, so that the magnetic field distribution in the channel is changed, the magnetic field gradient is reduced, the length of an ionization area is increased, and the krypton working medium is ionized more sufficiently in the channel.

The invention discloses a nuclear magnetism safety interval confirmation device, and the device comprises a quantum noise suppression module which is used for eliminating radar signal noise caused by the quantum tunneling effect on the surface of a metal object in an ultrahigh field intensity environment; the multi-sensor fusion center is used for integrating the radar cleaning signal, the real-time magnetic field intensity data and the terahertz penetrability detection result to generate fused object position information; the dynamic magnetic field reconstruction engine is used for calculating a magnetic field distortion gradient by analyzing Hall sensor array data and a magnetohydrodynamic model in real time; the nonlinear danger scoring module is used for receiving object distance, magnetic field gradient, existence time and object classification data; the hierarchical response system is used for triggering a corresponding response according to the danger score; and the cesium atomic clock synchronization module is used for eliminating a timing error caused by a time crystal effect through a block chain timestamp verification mechanism. According to the invention, risk closed-loop control in a high-field-intensity MRI environment is truly realized.

The invention discloses a copper wire tinning method for tinned copper stranded wire production, which relates to the technical field of metal surface treatment, and comprises the following steps: releasing a copper wire to an ionic liquid electrophoresis tank, applying an electric field to strip surface oxides, and then carrying out three-stage countercurrent rinsing to generate a clean copper wire; putting the clean copper wire into a composite plating tank, monitoring the tin liquid viscosity and the copper wire linear speed in real time, calculating the magnetic field gradient, and controlling tin crystal oriented growth according to the magnetic field gradient to generate an oriented crystallization tinned copper wire; the surface temperature of the directionally crystallized tinned copper wire is monitored in real time and compared with a preset temperature threshold value, a temperature permission trigger signal is generated, the annular array spray gun is triggered to work according to the temperature permission trigger signal, and a densified tinned copper wire is generated; and the densified tinned copper wire is scanned through a micro-focus CT scanner, a gap three-dimensional point cloud picture is generated, the gap size and the normal angle of the gap three-dimensional point cloud picture are analyzed, the optimal spraying parameters are recognized, and the passivation film tinned copper wire is generated.

The invention discloses liquid dressing production equipment, and relates to the technical field of medical instrument production equipment.The liquid dressing production equipment is characterized in that firstly, neodymium iron boron magnets of a driving rotary disc and a driven rotary disc are in coupling transmission, and a middle isolation sleeve is matched, so that complete physical isolation inside and outside a kettle is achieved; a uniform magnetic field generated by Helmholtz coils is used for weakening attraction force among particles, a dynamic magnetic field gradient formed by rotation of a permanent magnet arranged in a stirring paddle can cooperate with mechanical shearing, so that the internal structure of an aggregate is deeply destroyed, meanwhile, the Helmholtz coils in three orthogonal directions provide a global uniform static magnetic field, and the aggregate is fully dispersed. The stability of the magnetic background in the kettle can be ensured, the global effect of the dynamic magnetic field gradient is matched, the local defect caused by purely depending on mechanical shearing is avoided, the dispersion uniformity is remarkably improved, the influence of the concentration gradient on the physical and chemical properties is reduced, and the influence of initial agglomeration on the subsequent process can be reduced by utilizing the efficient dispersion capacity of the magnetic mixing assembly.

The invention relates to the technical field of electromagnetic measurement, and discloses a measurement unit stabilization method and system, electronic equipment and a storage medium, and the method comprises the steps: obtaining three-dimensional displacement trajectory data in real time, and building a motion error compensation model containing a mechanical vibration direction vector and a phase offset; on the basis of asymmetric magnetic pole distribution, combined with phase difference calculation of a magnetic circuit gradient direction vector and a mechanical vibration direction vector, a closed loop current orthogonal to the mechanical vibration direction vector is generated on an interface to realize gradient isolation; based on a multi-branch common-mode suppression mechanism, an interference signal reaches a preset attenuation amplitude before a loop is closed through combination of a magnetic core impedance matching characteristic and an eddy current effect; and performing dynamic matching based on the displacement parameter and an electromagnetic interference attenuation result, adjusting a magnetic pole inclination angle in real time, and forming a closed-loop control path of magnetic field gradient compensation and mechanical vibration suppression. According to the invention, the stability and anti-interference capability of the measuring unit under severe working conditions can be improved.

The invention relates to the field of control valve positioning, and discloses a high-precision positioning system of a water treatment multi-path control valve based on magnetic induction. Through rigid linkage of the magnet and the valve element driving unit, accurate mapping of magnet rotation / linear motion and valve element stations is achieved. A sensing device array is adopted to detect the gradient change of a three-dimensional magnetic field in a non-contact manner along the movement track of a magnet, and the sensor array is arranged in a circumferential annular or axial linear manner. A pre-calibrated magnetic field intensity-spatial position multi-dimensional database and a two-stage matching strategy are adopted. For long-stroke application, a sensor relay detection technology is adopted. The method has the advantages of high precision, high reliability and low cost, and is suitable for the fields of water treatment, industrial automation and the like.

The invention relates to the technical field of magnetic field measurement error compensation, in particular to a single-axis Hall surface magnetic rapid imaging analysis system, which is characterized in that a magnetic field gradient real-time analysis unit calculates a magnetic field gradient change rate through a sliding window weighted difference algorithm, identifies a magnetic pole transition region and analyzes the magnetic field gradient change rate. The multi-source error coupling modeling unit synchronizes Hall probe spacing fluctuation, inclination angle and magnetic field gradient data and constructs a composite compensation function, the adaptive compensation unit corrects and counteracts spacing attenuation and projection errors through two-stage assembly lines, and the nonlinear trigger control unit generates an adaptive encryption trigger signal, so that the sampling spacing decreases progressively along with the gradient change rate, and the error compensation is realized. And the magnetic field distribution reconstruction unit fuses the compensation data and the sampling sequence, reconstructs a continuous magnetic field distribution curve by adopting gradient constraint cubic spline interpolation, accurately outputs a magnetic pole boundary position and a surface magnetic field intensity quantification result, and improves the surface magnetic imaging precision and efficiency.

The present invention concern a method and a device for the isolation of non-magnetic cells from a heterogeneous sample solution containing biological material including desired and undesired cells. The method comprises the steps of: —adding magnetic or magnetizable particles to the sample, wherein said particles have sizes in a range from 100 nm to 4 μm and exhibit surface components which support specific association with target cells, wherein said target cells comprise are either said desired or said undesired cells; —decreasing said external magnetic field gradient; —incubating said sample solution with said magnetic particles to obtain a magnetized cell fraction; —washing said magnetized cell fraction using a washing solution to reduce non-specific binding; —increasing said external magnetic field gradient; —separating said magnetized cell fractionation of target cells from said sample; wherein said sample solution is subjected to an external magnetic field gradient throughout said adding, incubating, washing and separating steps, and wherein said sample solution is rotated at least during said adding, incubating and washing steps.

A magnetic resonance imaging apparatus according to an exemplary embodiment includes a magnet, a gradient magnetic field coil, a sequence controller, and a plurality of metal shims. The magnet generates a static magnetic field. The gradient magnetic field coil applies a gradient magnetic field to a subject. The sequence controller applies a current to the gradient magnetic field coil by executing a first pulse sequence. The plurality of metal shims is used for passive shimming in which the plurality of metal shims is arranged based on the static magnetic field distribution in a state where a temperature of the gradient magnetic field coil is increased by execution of the first pulse sequence. The sequence controller executes a second pulse sequence for imaging the subject after completion of the passive shimming.

The invention belongs to the technical field of liquid level meters, and relates to a liquid level remote alarm system based on the internet of things and a liquid level meter thereof, and the liquid level remote alarm system comprises a liquid level detection module, a magnetic field interference compensation module, a turning plate stagnation detection module, a dynamic compensation module and a remote alarm module. Based on axial magnetic field gradient changes and radial magnetic field steady state characteristics, interference components are stripped, high-precision liquid level data are reconstructed, overturning action time sequence characteristics and mechanical vibration spectrum characteristics are fused to dynamically recognize the clamping stagnation state, liquid level deviation caused by magnetic field interference and mechanical clamping stagnation is cooperatively corrected, and multi-stage early warning of liquid level abnormity is achieved. The limitation of static shielding and manual maintenance in the prior art is broken through, the anti-interference capability and data reliability of liquid level signals under complex working conditions are remarkably improved, and a more accurate and stable liquid level monitoring solution is provided for industrial process control.

The invention discloses a real-time video positioning method based on ferromagnetic substance magnetic field signal three-dimensional imaging simulation, and relates to the field of ferromagnetic substance detection in a medical scene nuclear magnetic resonance room, and the method comprises the steps: carrying out the segmentation fitting of a magnetic field gradient through employing a B-spline basis function; performing omni-directional calibration on the array through a rotating platform, and establishing a nonlinear mapping matrix of sensor output and real magnetic field intensity; extracting target shape features; performing optical flow estimation on the video frame, and compensating magnetic field measurement delay caused by target motion; establishing an incidence matrix of the target state vector and the measured value; reconstructing the three-dimensional space distribution of the ferromagnetic substance through an inversion method based on a perspective transformation model; and fusing the three-dimensional imaging result with the real-time video. Magnetic field measurement delay caused by target motion is compensated by performing optical flow estimation on a video frame, and a state estimation convergence speed is improved by estimating a multi-mode parallel state.

The invention discloses an unmanned ship gravity and magnetic measurement method and system, and belongs to the technical field of geophysical exploration, and the method comprises the steps: obtaining the real-time attitude data of an unmanned ship, and generating an inclination angle compensation parameter; adjusting data acquisition frequency according to the inclination angle compensation parameter, and generating a positioning enhancement signal; triggering collection operation data based on the positioning enhancement signal, and generating gravity original data and magnetic force original data; extracting magnetic field gradient abrupt change points in the magnetic force original data, and generating wave characteristic parameters; fusing the inclination angle compensation parameter, the wave characteristic parameter and the gravity original data to generate a wave noise compensation value; and correcting the wave noise compensation value to generate target gravity field data. According to the method, three core technology systems of dynamic inclination angle closed-loop compensation, magnetic gradient-wave feature mapping modeling and time accurate alignment triggering are adopted, the interference influence of wave noise on a gravity field can be effectively overcome, and time-space synchronization jump of gravity and magnetic measurement is achieved.

The invention provides a quantitative detection method and system for corrosion of steel bars in concrete, and belongs to the technical field of nondestructive testing and health monitoring of civil engineering structures. According to the method, an alternating weak magnetic field is applied to a reinforced concrete structure through a controllable magnetic field excitation device; a superconducting quantum interference magnetic sensor array is adopted to collect magnetic field response signals, and a space magnetic field gradient data set is obtained; performing wavelet packet decomposition and feature extraction on the data set to obtain a corrosion feature frequency band signal; based on a magnetic diffusion-corrosion coupling physical model, inversely calculating steel bar section corrosion rate distribution; and generating and outputting a three-dimensional corrosion distribution cloud picture and a quantitative evaluation report. The system comprises a controllable magnetic field excitation device, a superconducting quantum interference magnetic sensor array, a data processing and inversion calculation device and a result output device which are sequentially connected and cooperatively work. According to the invention, nondestructive, accurate and quantitative detection of corrosion of steel bars in concrete is realized, and the method has the advantages of strong deep penetration ability, high sensitivity to micro-corrosion, good field applicability and the like.

A magnetic field measurement method based on multi-focus array laser pumping atomic spinning comprises the steps that pumping light is subjected to phase modulation through a spatial light modulator to generate a multi-focus circularly polarized light array, light intensity distribution of focuses of the multi-focus circularly polarized light array on a transverse plane is uniform, and the distances between the focuses of the multi-focus circularly polarized light array are consistent; therefore, the problem of non-uniform distribution of the laser in the transverse direction due to Gaussian light intensity is effectively compensated. In the longitudinal direction, according to the law of energy attenuation caused by the action of light and atoms, the focus light intensity is designed to be gradually enhanced along with the z-axis depth in combination with an anti-Lambert-W function, and a focus array is uniformly focused at the center of an alkali metal gas chamber by expanding the focus depth, so that the transverse and longitudinal polarizability uniformity of alkali metal atoms is remarkably improved, the optical frequency shift virtual magnetic field gradient is inhibited, and the stability of the alkali metal gas chamber is improved. And the common-mode rejection ratio, the signal-to-noise ratio and the response sensitivity of the SERF magnetic field measuring device are improved. The focus array is optimized in real time through detection feedback, efficient compensation and regulation are achieved, and the method is suitable for accurate measurement of the sub-fT-level weak magnetic field.

The invention discloses a current sensor structure based on tunnel junction magnetoresistance and a manufacturing method, the current sensor structure comprises a first array group and a second array group, and the first array group and the second array group are composed of a first tunnel junction magnetoresistance array unit and a second tunnel junction magnetoresistance array unit which are arranged along the same sensing direction, and a first electrode unit and a second electrode unit; the sensitive axis directions of the first array group and the second array group are opposite to each other, and the second array group rotates by 180 degrees relative to the first array group in the physical space and then is in cross connection through metal electrodes. The tunnel junction magnetoresistive sensor has the beneficial effects that the tunnel junction magnetoresistive sensor comprises the first array group and the second array group, and the first tunnel junction magnetoresistive array unit and the second tunnel junction magnetoresistive array unit in the first array group and the second array group respectively comprise eight arrays, so that the tunnel junction magnetoresistive sensor has higher physical reliability and stability; the measurement error of the tunnel junction magnetoresistive sensor caused by the magnetic field gradient can be reduced; when the magnetic field and the current are measured, the magnetic field with the magnitude as low as 17 nT / Hz can be measured.

A sensor device for determining the orientation of a magnet that is pivotable about a reference point. the sensor device includes a semiconductor substrate including a first and a second magnetic sensor spaced apart in a first direction, each configured for measuring a first magnetic field component oriented in the first direction, and a second magnetic field component oriented in a second direction; wherein the sensor device further includes a processing circuit configured for determining: i) a first magnetic field gradient; ii) a second magnetic field gradient; iii) a first angle based on the first magnetic field gradient; iv) a second angle based on the second magnetic field gradient. A sensor system includes the sensor device and the magnet.

The invention discloses a double-spindle turning and milling combined machining center, and relates to the technical field of machine tool machining, the double-spindle turning and milling combined machining center comprises a lathe bed, the lathe bed comprises a spindle unit, the spindle unit comprises a first spindle unit and a second spindle unit, and the first spindle unit and the second spindle unit are oppositely arranged in the horizontal direction and are both in sliding connection with the lathe bed through sliding mechanisms; and the main shafts are independently connected with main shaft driving motors. Temperature field distribution of different axial positions at the front end of the main shaft is identified in real time, each annular electromagnet is independently regulated and controlled to construct a non-uniform magnetic field gradient in the electric control heat conduction pad, and the magnetic response phase change microcapsules are driven to be directionally enriched towards a high-temperature area, so that cooling capacity space distribution and thermal load space distribution are dynamically matched in real time; and the main shaft thermal drift is actively inhibited from the source.