225 results about "Magnetic field gradient" patented technology

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 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.

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.

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 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 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 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.

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 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.

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.

There is provide a circular accelerator and a particle beam therapy system that can improve the beam extraction efficiency. A circular accelerator that accelerates and extracts charged particle beams circulating in a magnetic field includes a first magnetic field region in which closed trajectories of the beams with different energies are eccentric and which has a magnetic field gradient decreasing in the magnetic field toward an outer peripheral side and a second magnetic field region having a magnetic field gradient increasing in the magnetic field toward the outer peripheral side. A border between the first magnetic field region and the second magnetic field region is located on a downstream side in a traveling direction of the beam with respect to a predetermined region in which an interval between the closed trajectories of the beams with the different energies is narrowest.

The application discloses a device and method for compensating magnetic field gradient of a segmented dDNP polarization system, which comprises a gradient monitoring module and a dynamic compensation module. The gradient monitoring module comprises a magnetic sensor combination, which comprises at least two magnetic sensors distributed along the transfer path direction of a sample, and the magnetic sensors are used for detecting a first gradient magnetic field corresponding to the transfer path of the sample. The dynamic compensation module comprises a segmented gradient coil, which is arranged along the transfer path of the sample to form multiple independent coil units. The current of each independent coil unit is independently adjusted according to the first gradient magnetic field, so that the segmented adjustment and overall homogenization of the magnetic field gradient of the transfer path are realized. The dynamic magnetic field gradient inside the polarizer is measured in real time by using the magnetic sensor combination, and the precise compensation of the gradient magnetic field is realized through the reverse compensation of the segmented gradient coil, so that the high polarization fidelity of the sample in the transfer process is ensured.

The present application relates to the technical field of magnetic shoe of wall-climbing robot, in particular to a special-shaped magnetic shoe of wall-climbing robot. The present application breaks through the non-uniform central angle permanent magnet arrangement structure, combines the adjacent permanent magnet radial reverse magnetization strategy, constructs an efficient closed magnetic circuit inside the magnetic shoe, thereby avoiding the symmetric magnetic field distribution mode of the traditional magnetic shoe, forcing the magnetic induction lines to densely converge along the preset path, significantly suppressing the edge magnetic leakage phenomenon, making the horizontal direction magnetic flux density jump up, and fundamentally reconstructing the magnetic field gradient distribution, providing the wall-climbing robot with revolutionary anti-skid traction force guarantee.

The invention relates to the technical field of water treatment, and discloses an intelligent response type mine wastewater treatment system which comprises a physical treatment subsystem and a control subsystem. The control subsystem calculates a normalized effective contact efficiency factor and a fluid drag strength factor based on the collected fluid flux and source frequency data. The calculation module adjusts the mechanical shear power of the mixing unit according to the effective contact efficiency factor, and keeps the Damkler number in the reaction system constant so as to compensate the contact time loss; and adjusting the excitation current of the separation unit according to the fluid drag strength factor, constructing a dynamic magnetic field gradient balanced with a fluid drag force vector, and executing pre-excitation when an impact precursor is identified. When the fluid drag strength exceeds a physical limit, the system controls the dosing interface to perform supersaturated dosing. Through cooperative regulation and control of a multi-dimensional physical field and chemical potential energy, rapid response and stable treatment of the unsteady hydraulic load are achieved.

The invention discloses an online magnetic separation device for packaging aluminum foil casting melt inclusions, and relates to the field of material magnetic separation. An on-line magnetic separation device for packaging aluminum foil casting melt inclusions comprises a separation box and further comprises an installation box fixedly connected in a feeding port of the separation box, a magnetic separation device and a control device, the multiple groups of flow guide pipes are all mounted in the mounting box, each flow guide pipe is provided with a hollow pipeline, and the hollow pipelines of the flow guide pipes are used for guiding a liquid solution to enter the separation box; a cavity is formed in the flow guide pipe, and a high-temperature-resistant electromagnet is installed in the cavity. The spiral groove is formed in the hollow pipeline of the flow guide pipe; through the flow guide pipe with the spiral groove, impurities are adsorbed in a gradient mode through a magnetic field in the spiral groove, the magnet does not make direct contact with a melt or the impurities, mechanical abrasion is avoided, only the flow guide pipe needs to be replaced during follow-up replacement, the high-temperature-resistant electromagnet can be reserved, and resources are effectively saved.

A traceable multi-mode extremely weak magnetic field measuring device and method, comprising helium-3 atoms and an atomic magnetometer in a spin-exchange relaxation-free state, the helium-3 atoms polarized by metastable exchange optical pumping under an extremely weak magnetic field provide a traceable magnetic field value for the atomic magnetometer, the value is compared with the output response of the atomic magnetometer to obtain a calibrated scale factor of the atomic magnetometer, so that the measurement values of the atomic magnetometer are traceable. The atomic magnetometer meter head comprises four independent detection channels, the four detection channels are obtained by beam splitting of two detection lasers with different frequency detuning amounts, and the channels have high consistency. The method proposed by the application is compatible with the cooperative use of multiple probes, and can realize single-meter-head multi-channel measurement, meter-head internal magnetic field gradient measurement and meter-head inter-magnetic field gradient measurement three measurement modes, each mode has high consistency and high sensitivity.

The utility model discloses a magnetic induction encoder for input equipment, and relates to the field of input equipment, the encoder comprises a mechanical main body formed by a fixed base and a rotatable part, and the rotatable part realizes the circumferential motion freedom degree relative to the fixed base through an axial supporting structure. The rotatable part is provided with periodically distributed magnetic coding structures in the circumferential direction, and the magnetic coding structures form continuously changing magnetic field gradient distribution in the circumferential direction. According to the encoder, a detection medium is converted from an optical nick to a magnetic array, so that the rigid constraint of a physical structure can be broken through, and dynamic precision adjustment is realized by utilizing the programmable characteristic of magnetic field distribution. The non-contact detection mechanism not only can effectively eliminate performance degradation caused by mechanical wear, but also can be compatible with different response curves through algorithm optimization, and endows the input equipment with intelligent characteristics of self-adaptive environment and use scene.

The invention relates to a method of MR imaging of an object (10) positioned in an examination volume of a MR device (1). It is an object of the invention to enable efficient spiral MR imaging without blurring artefacts, even in situations of strong B0 inhomogeneity. The method of the invention comprises the following steps: —subjecting the object (10) to an imaging sequence comprising at least one RF excitation pulse and modulated magnetic field gradients, —acquiring MR signals along two or more planar spiral k-space trajectories (31, 32, 33), wherein the radial k-space speed, i.e. the rate of variation of the radial distance from the spiral origin is essentially constant along each planar spiral k-space trajectory, and wherein the two or more k-space trajectories (31, 32, 33) are offset in-plane from each other, and—reconstructing an MR image from the acquired MR signals. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

A double-sided electric heating sheet magnetic field suppression configuration design method for an atomic gas chamber is used to solve the problem of the interference magnetic field and magnetic field gradient generated by the electric heating structure in the background technology. Through simultaneous optimization design of the parameters of the upper and lower heating sheets, the overall structure is formed to effectively suppress the electric heating magnetic field and improve the magnetic field uniformity. The method is characterized in that the NSGA-II algorithm based on Pareto sorting is used to simultaneously optimize the parameters of the two electric heating sheets located on the symmetric surface of the gas chamber, obtain the optimal parameter combination of the two electric heating sheets, and realize the simultaneous optimization of the wiring design of the double-sided electric heating sheets.

The invention provides a sensor device and a sensor system for determining an orientation of a magnet. A sensor device for determining the orientation (alpha, beta, phi, psi) of a magnet pivotable about a reference point (Pref), the sensor device comprising: a semiconductor substrate (703) comprising first and second magnetic sensors (S1, S2) spaced apart in a first direction (X), each magnetic sensor being configured for measuring a first magnetic field component (Bx1, Bx2) oriented in the first direction (X); a second magnetic field component (Bx2) oriented in a second direction (Y) and a second magnetic field component (By1, By2) oriented in a second direction (Y); wherein the sensor device further comprises processing circuitry configured to: i) determine a first magnetic field gradient (dBx / dx); ii) determining a second magnetic field gradient (dBy / dx); iii) determining a first angle (alpha, psi) based on the first magnetic field gradient (dBx / dx); iv) determining a second angle (beta, phi) based on the second magnetic field gradient (dBy / dx). A sensor system includes the sensor device and the magnet.

The invention relates to the technical field of rheological testing and material characterization, and provides a local rheological testing system and device based on electromagnetic driving and visual displacement tracking, and the system comprises a magnetic field generation module which is used for generating a stable magnetic field for magnetizing a magnetic needle in a sample area and a periodic gradient magnetic field for driving the magnetic needle, and a driving module, the magnetic field generation module is used for providing corresponding steady-state and alternating current excitation for the magnetic field generation module, and the image acquisition module is used for generating a uniform linear magnetic field gradient in a central area by a gradient field Maxwell configuration coil pair and an external trigger synchronization mechanism through the arrangement of the structures such as the gradient field Maxwell configuration coil pair and the external trigger synchronization mechanism; the driving force acting on the magnetic needle is ensured to be stable and repeatable; an external trigger synchronization mechanism controls driving signals to be strictly synchronized with image acquisition, and magnetic needle displacement and phase difference are accurately extracted by combining image recognition and a sub-pixel positioning algorithm, so that magnetic field fluctuation and time sequence errors are effectively reduced, the rheological parameter inversion precision is improved, and the problems of large errors and high cost in the prior art are solved.

The application relates to the technical field of downhole operation of oil exploitation, in particular to a lost fish head detection device and method for taking and replacing a casing, the method comprising the following steps: by collecting the magnetic variable of a downhole probe at each sampling depth, a potential interference section is first determined; then, by combining the magnetic field gradient distribution and the horizontal magnetic field direction characteristics, the magnetic field change balance degree and the direction consistency are calculated, the stratum lithology and external interference are effectively removed, and the real lost fish head section is accurately locked; finally, the horizontal distance is calculated by using the magnetic field vector weighted summation, and the fish collecting strategy is output. The application aims to improve the accuracy of fish head positioning and the fish collecting success rate.

The present invention relates to a method and a device for isolating non-magnetic cells from a heterogeneous sample solution containing biological material comprising desired and undesired cells. The method comprises the following steps: - adding magnetic or magnetizable particles to the sample, wherein the particles have a size in the range of 100 nm to 4 pm and exhibit a surface composition that supports specific binding to target cells, wherein the target cells comprise the desired cells or the undesired cells; - reducing the external magnetic field gradient; - incubating the sample solution with the magnetic particles to obtain a magnetized cell fraction; - washing the magnetized cell fraction using a washing solution to reduce non-specific binding; - increasing the external magnetic field gradient; - isolating the magnetized cell fraction of target cells from the sample; wherein the sample solution is subjected to an external magnetic field gradient throughout the adding, incubating, washing and isolating steps, and wherein the sample solution is rotated at least during the adding, incubating and washing steps.

Disclosed in the present invention are a superconducting magnet system for esophageal atresia traction anastomosis, and a method. The system comprises: a superconducting magnet device, a movable flat plate, a support, a ferromagnetic core and a permanent magnetic core, wherein the movable flat plate is movably arranged inside a central hole of the superconducting magnet device, the support is fixedly connected to the superconducting magnet device, and the ferromagnetic core and the permanent magnetic core are placed inside the central hole of the superconducting magnet device and are respectively located at a proximal esophageal end and a distal esophageal end of an esophageal atresia target; the superconducting magnet device is configured to generate a uniform magnetic field and a gradient magnetic field inside the central hole; and the ferromagnetic core and the permanent magnetic core are configured to provide opposite traction forces for the esophageal atresia target under the uniform magnetic field and the gradient magnetic field. According to the present application, by combining the uniform magnetic field, the gradient magnetic field, the ferromagnetic core and the permanent magnetic core, opposite traction forces that have adjustable magnitudes and that do not require directional adjustment are provided for the esophageal atresia target, thereby improving the traction force intensity, control flexibility and control precision.