174 results about "Magnetism" patented technology

The invention relates to the technical field of magnetic separation, in particular to a magnetic gradient separation fire metal material evidence screening machine and a multistage magnetic field regulation and control method thereof.The magnetic gradient separation fire metal material evidence screening machine comprises a machine body, a feeding pipe and rotating cylinders are rotationally connected to an inner cavity of the machine body, magnetic separation assemblies are installed between the feeding pipe and the rotating cylinders and between the two rotating cylinders, and driven gears are installed on the outer walls of the feeding pipe and the rotating cylinders; according to the multi-stage magnetic separation device, the multi-stage magnetic separation design is adopted, magnetic force sequentially increased from top to bottom of the magnetic separation assembly is combined with centrifugal force generated by rotation of the feeding pipe and the rotating cylinders, and materials are evenly dispersed and make full contact with the magnetic separation assembly; meanwhile, the valve plate assemblies are sequentially opened in the descending process of the abutting blocks, so that the materials sequentially fall down layer by layer, sorting disorder caused by falling of a large number of materials at a time is avoided, the materials can be kept for enough time on each magnetic separation assembly, it is ensured that metal material evidences with different magnetisms are fully adsorbed, and the screening accuracy is greatly improved.

The invention discloses a method for measuring and analyzing residual magnetism characteristics of an iron core. According to the method, a to-be-detected iron core is demagnetized, preset residual magnetism is set, direct-current voltage excitation with opposite polarities, the same amplitude and the same duration is applied to a primary winding of the to-be-detected iron core, and transient current response signals are synchronously collected; two groups of current under positive / negative polarity excitation are extracted, and the residual magnetism direction is judged by comparing the change rate of the current; a curve of equivalent resistance changing along with time is calculated based on forward current and voltage, a resistance value corresponding to a characteristic inflection point moment is selected, the resistance value is substituted into a pre-established residual magnetism-equivalent resistance empirical formula to deduce the magnitude of residual magnetism, and a matched iron core residual magnetism detection and demagnetization integrated system integrates information management, residual magnetism detection, demagnetization and display modules. And closed-loop automation of detection, analysis and demagnetization is realized. According to the method, a magnetic field sensor is not needed, the residual magnetism direction and size can be synchronously obtained in a high-precision and robust mode only through port electric signals, and the method is suitable for on-site off-line or live detection.

The invention discloses an overlying strata fracture electromagnetic imaging method and a grouting system, and particularly relates to the technical field of geological fracture imaging. The invention discloses an overlying strata fissure electromagnetic imaging method and a grouting system. The method comprises the steps that S1, magnetic source slurry containing permanent magnetic material particles is injected into a target overlying strata fissure area through the grouting system; s2, magnetizing the magnetic source slurry injected into the crack through an electromagnetic coil group arranged on the grouting system; s3, tracer slurry containing magnetic responsive nanoparticles is injected into the fissure area where the guiding magnetic field is formed through a grouting system; s4, in-hole electromagnetic detection equipment is adopted to scan the fracture area filled with the tracing slurry, and electromagnetic response data are obtained; and S5, processing and analyzing the electromagnetic response data. According to the overlying strata fissure electromagnetic imaging method and the grouting system provided by the invention, through a technical path of'pilot magnetism and post tracing ', the tracing slurry is actively guided to directionally migrate by utilizing the magnetic field, and high-precision filling and electromagnetic imaging of an overlying strata fissure network are realized.

The invention discloses a cerium-containing high-abundance rare earth sintered neodymium iron boron permanent magnet which does not contain heavy rare earth and does not need a grain boundary diffusion process and a preparation method thereof. The magnet is formed by crushing and mixing three alloy casting pieces, the three alloy casting pieces are an Nd / Pr-rich phase, a Ce-La-rich phase and a Y-Nd-rich phase respectively, and Ce accounts for more than or equal to 30wt% of the total amount of all rare earth elements; the trace elements (Al, Cu, Ga, Nb, Zr and the like) are uniformly introduced in the smelting stage of each main phase, and grain boundary reconstruction is induced through in-situ hydrotreating to form a thin and continuous rare earth-rich grain boundary phase; and after orientation compression molding, vacuum sintering and multi-stage heat treatment, a sintered magnet with excellent magnetic performance is obtained. According to the product, the intrinsic coercive force Hcj is larger than or equal to 15 kOe, the residual magnetism Br is larger than or equal to 13.7 kG, and the maximum magnetic energy product (BH) max is larger than or equal to 39 MGOe. The problems that a high-Ce magnet is low in coercive force, discontinuous in grain boundary phase and the like are solved, the method does not need to depend on Dy / Tb heavy rare earth and a grain boundary diffusion technology thereof, the cost is reduced by 30% or above, and the method is suitable for the fields of new energy automobiles, wind power generation and the like and has a good industrialization prospect.

The invention discloses a sintered neodymium-iron-boron permanent magnet material with a low coercive force temperature coefficient for a new energy automobile, and relates to the technical field of sintered neodymium-iron-boron permanent magnet materials. Collaborative optimization of high residual magnetism and high coercive force is realized through preparation of the sintered neodymium-iron-boron permanent magnet material; the performance bottleneck of a traditional sintered neodymium-iron-boron magnet material is broken through, and the energy density and the demagnetization resistance of the magnet are doubly improved, so that the magnet is excellent in high-temperature and high-intensity magnetic field environments.

The invention discloses a preparation method of a ferromagnetic annular rubber magnet, which comprises the following steps: providing a sheet material of the rubber magnet, and cutting the sheet material into strips to form a plurality of rubber magnetic strips; performing primary cold pressing treatment on the rubber magnetic strip, so that the two ends of the rubber magnetic strip are jointed to form a conical annular magnet; performing secondary cold pressing treatment on the conical annular magnet to form an annular magnet; and carrying out hot-pressing vulcanization, cooling shaping and magnetizing on the annular magnet in a high-intensity magnetic field to realize special magnetic circuit magnetization so as to obtain the ferromagnetic annular rubber magnet. According to the preparation method, the annular rubber magnet which is high in raw material utilization rate and has strong magnetism can be prepared.

The invention provides a spacecraft magnetic moment measurement method and system based on a four-point method, and the method comprises the steps: controlling a spacecraft to rotate a circle after a plurality of magnetometers are radially arranged at the geometric center height of the spacecraft, and measuring the magnetic intensity values corresponding to four preset measurement points through the plurality of magnetometers; calculating a plurality of key magnetic moment values according to the magnetic intensity values and the measurement spacing values corresponding to the four measurement points; based on the multiple key magnetic moment values, the magnetic core height of the spacecraft is obtained through calculation; adjusting the arrangement height of the plurality of magnetometers to the magnetic core height of the spacecraft; and controlling the spacecraft to rotate for a circle, and obtaining a magnetic moment measurement value of the spacecraft according to the magnetic intensity readings corresponding to the magnetic core heights of the plurality of magnetometers. According to the scheme provided by the invention, the equatorial plane positioning basis of the near-field method can be adjusted from the geometric center of the spacecraft to the magnetic core, the magnetic moment is accurately measured under the condition that the magnetism in the spacecraft is relatively dispersed, and the measurement precision and reliability of the magnetic moment of the spacecraft are improved.

The invention provides samarium-iron-nitrogen magnetic powder and a preparation method and application thereof, the samarium-iron-nitrogen magnetic powder comprises a first samarium-iron-nitrogen particle, the surface of the first samarium-iron-nitrogen particle is provided with at least one step structure, and each step structure comprises at least two layers of steps. The surface of the first samarium-iron-nitrogen particle is of a step structure, the first samarium-iron-nitrogen particle is high in density, few in crystal defect and high in intrinsic coercive force, and when the samarium-iron-nitrogen magnetic powder comprising the first samarium-iron-nitrogen particle is applied to preparation of a magnet, the residual magnetism and the intrinsic coercive force of the magnet can be improved, and the service life of the magnet can be prolonged.

To provide a magnetic shield device for shielding magnetism from the outside, which maintains a low magnetic field environment in the magnetic shield device (magnetic shield space) and reduces a fluctuation amount of a magnetic field by suppressing temperature fluctuation of the magnetic shield device itself causing magnetic field fluctuation (maintaining temperature stability).SOLUTION: The magnetic shield device 1 includes two or more layers of magnetic shield members 11,12, a thermally conductive member 13 which can accommodate a magnetic sensor and a test object therein, is disposed outside the innermost magnetic shield member 11, and is in thermal contact with substantially the entire surface of the innermost magnetic shield member 11, and a thermally conductive member temperature stabilizing means (here, a constant-temperature fluid 14, a constant-temperature fluid passage 15, a constant-temperature fluid delivery function, and a heat insulating layer 19) for maintaining the thermally conductive member 13 at a constant temperature.SELECTED DRAWING: Figure 2

The invention belongs to the technical field of magnetic measurement testing, and particularly relates to an implementation method of a multi-layer magnetic field coil, which can realize the consistency of the side-to-side ratio of different layers of coil windings. According to the implementation method of the multi-layer magnetic field coil, along with the increase of the number of winding layers, the edge-to-edge ratio of the multi-layer magnetic field coil can be kept unchanged all the time, it is ensured that the technical performance of the magnetic field coil is kept unchanged, and the consistency of the edge-to-edge ratios of different layers of coil windings is achieved.

The invention provides a layered Van der Waals material with full-compensation ferrimagnetism and a topological Hall effect as well as a preparation method and application of the layered Van der Waals material. The chemical formula of the material is MnxCrTe2, wherein 0 lt; and x is 1. The material provided by the invention has a wide compensation temperature range, a large magnetoresistance effect, anisotropy and a topological Hall effect, is a CrTe2 intercalation ferromagnetic material doped in different proportions, and can realize optimization and continuous adjustability of performances such as magnetism, Curie temperature and Hall parameters of the material through regulation and control of mechanisms such as the doping proportion, the temperature and the magnetic field; and a material basis is provided for researching the application of the Mn intercalation CrTe2 crystal material in the field of magnetic induced storage.

The application relates to the technical field of magnetic variable measurement, in particular to a magnetic induction electric field dynamic compensation control method based on online disturbance response, which comprises the following steps: injecting a characteristic test signal to the induction axis of a magnetism sensor, extracting an amplitude-phase deflection response characteristic by using a digital lock-in amplifier to construct a dynamic mapping matrix, and online identifying the gain, time constant and pure lag measurement model parameters of a calibration coil loop; an error processing unit sets an error offset coefficient and generates a reverse compensation control instruction to drive a loop to generate an offset magnetic field; the intensity of a multi-node parasitic induction electric field is obtained as a dynamic weight, a Steiner-Weber algorithm is used to solve a space equivalent interference radiation center, and the test duty ratio and calibration weight of each node are adjusted. The application actively injects orthogonal signals to online decouple a measurement baseline drift, and adaptively cooperates with a multi-node measurement array, so that wide-band and extremely low dynamic residual measurement of a large-space alternating magnetic field is realized.

The invention discloses an air-magnetic overhanging type micro-low gravity test air-floating workbench capable of inhibiting residual magnetism and eddy current interference. The air-magnetic overhanging type micro-low gravity test air-floating workbench comprises a rigid bearing framework and a functional composite material layer. The rigid bearing framework is made of non-magnetic high-specific-stiffness aluminum alloy, and mechanical supporting and magnetic field isolation are achieved. And the functional composite material layer is compounded by uniformly dispersing and consolidating corrosion-resistant nickel-based soft magnetic particles in a non-magnetic matrix, and is used as a gas-magnetic coupling working interface. The adopted nickel-based soft magnetic particles have high saturation flux density, low coercive force, high resistivity and good chemical stability, it is ensured that the functional composite material layer formed by the nickel-based soft magnetic particles has lasting and reliable working surface performance, and residual magnetism interference force and eddy current damping force are fundamentally eliminated on the premise that needed vertical adsorption force is maintained. According to the design, the unexpected horizontal disturbing force generated by the air floatation working table is reduced to one thousandth of the rated vertical bearing force of the gas magnetic bearing, and the precision of dynamic simulation in a micro-low gravity ground experiment is remarkably improved.

The utility model discloses a double-sided magnetic ring adaptive to a mobile phone, which comprises a shell, the shell is in a circular ring shape, the shell is made by adopting an alloy die-casting process and has higher strength, an installation cavity is arranged in the shell, a first magnetic ring, a refraction piece and a second magnetic ring are sequentially stacked in the installation cavity, and the refraction piece is arranged in the first magnetic ring. The sides, close to the refraction piece, of the first magnetic ring and the second magnetic ring are weak magnetic faces, the faces, away from the refraction piece, of the first magnetic ring and the second magnetic ring are strong magnetic faces, the refraction piece shields magnetism of the weak magnetic faces, magnetic force is refracted to the corresponding strong magnetic faces, and therefore the magnetic attraction force of the strong magnetic faces is enhanced. During use, one side of the magnetic ring is magnetically attracted to ferromagnetic metal surfaces such as handrails, refrigerator doors and iron wall surfaces, the other side of the magnetic ring is magnetically attracted to fix the mobile phone, the two sides of the magnetic ring are strong magnetic surfaces, adsorption is stable, reliability is high, the magnetic ring or the mobile phone on the magnetic ring can be taken down at any time, and use is more convenient.

The invention discloses a Terfenol-D magnetostrictive material-based optical force magnetometer magnetic measurement method, which comprises the following steps of: firstly, densely winding a single-mode optical fiber on the surface of a Terfenol-D magnetostrictive element in multiple circles, so that the magnetostrictive deformation of the Terfenol-D magnetostrictive element under the action of an external magnetic field is transmitted to the single-mode optical fiber; an unequal-arm Mach-Zehnder interferometer is constructed; the method comprises the following steps: applying magnetic fields under magnetic fields with different intensities, measuring change values of interference phases under the magnetic fields with different intensities according to a magnetostrictive strain relationship of a Terfenol-D magnetostrictive element, and establishing a calibration curve between the change values of the interference phases and the external magnetic field intensity; when a magnetic field to be measured acts on the sensing arm, the corresponding external magnetic field intensity is calculated according to the calibration curve. The magnetic measurement method is simple in structure, all signals are transmitted through an optical path, and electromagnetic interference can be effectively resisted; the measuring process is quick in response, and is suitable for quickly changing magnetic field measurement.

The application belongs to the field of material calculation simulation, and relates to a prediction method for magnetic coupling evolution characteristics of two-dimensional Janus materials based on first principles. The technical problem to be solved is that the existing technology fails to uniformly analyze the magnetic freedom and structural evolution behavior, resulting in interlayer abnormal shrinkage, spontaneous bond collapse and lack of judgment basis for the coupling relationship between magnetism and interlayer structure. The technical scheme comprises the following steps: establishing a crystal structure model taking MA2Z4 material as a mother body; cutting and constructing an asymmetric Janus single layer; constructing a double-layer AA stacking initial model; performing geometric structure optimization and static self-consistent calculation under non-spin polarization and spin polarization conditions respectively; comparing the interlayer spacing, magnetic moment distribution and electronic state characteristics under the two conditions; analyzing the inhibitory effect of interface magnetism on interlayer bonding tendency by combining the electron localization function and the crystal orbital Hamiltonian population; and finally establishing the cooperative evolution relationship among magnetism, interlayer coupling and electronic structure, thereby providing a theoretical basis for identifying stable double-layer van der Waals configuration.

This invention discloses a neodymium iron boron (NdFeB) magnet, its preparation method, and its applications. The NdFeB magnet of this invention includes a first easily demagnetized region, a first transition region, a non-easily demagnetized region, a second transition region, and a second easily demagnetized region, sequentially distributed along a direction perpendicular to the orientation. All three regions—the first easily demagnetized region, the second easily demagnetized region, the non-easily demagnetized region, the first transition region, and the second transition region—are rectangular. By controlling the Tb content introduced by diffusion in the transition region, the easily demagnetized region, and the non-easily demagnetized region, as well as the Dy content in all regions, this invention can reduce inter-regional Tb diffusion caused by the Tb concentration gradient difference in the transition region. This reduces the attenuation of the surface magnetism and magnetic flux of the NdFeB magnet while maintaining its remanence, thereby improving the demagnetization resistance of the NdFeB magnet. Furthermore, by setting the easily demagnetized region, the non-easily demagnetized region, and the transition region to be rectangular, this invention can improve the demagnetization resistance of the four corners and the long side of the NdFeB magnet.

Disclosed in the present invention are a neodymium-iron-boron magnet, and a preparation method therefor and the use thereof. In the neodymium-iron-boron magnet, the contents of heavy rare earth in a first vulnerable-to-demagnetization region, a second vulnerable-to-demagnetization region, a third vulnerable-to-demagnetization region and a fourth vulnerable-to-demagnetization region are the same; the contents of Tb in a first transition region, a second transition region, a third transition region and a fourth transition region are the same; the contents of Dy in the first vulnerable-to-demagnetization region, the transition region and an invulnerable-to-demagnetization region are the same and are not 0; the ratio of the content of Tb in the invulnerable-to-demagnetization region to the content of Tb in the first vulnerable-to-demagnetization region is (0-0.9):1; and the ratio of the content of Tb in the first transition region to the content of Tb in the first vulnerable-to-demagnetization region is (0.5-0.96):1. On the premise that the residual magnetism of the neodymium-iron-boron magnet of the present invention is guaranteed, the attenuation of the surface magnetism and magnetic flux of the neodymium-iron-boron magnet can be reduced, and the magnet has good demagnetization resistance.

The application relates to the technical field of refrigeration equipment, and provides a magnetic refrigeration structure, which comprises a magnetic field source and a ring-shaped magnetic conductive outer frame, the magnetic field source is arranged on the inner side of the magnetic conductive outer frame, the magnetic field source comprises parallel first magnetic supply groups and second magnetic supply groups, a plurality of first magnetic blocks are arranged in the first magnetic supply groups, a plurality of second magnetic blocks are arranged in the second magnetic supply groups, the polarities of the first magnetic blocks and the second magnetic blocks are opposite, the magnetic conductive outer frame forms working air gaps and a plurality of closed magnetic circuits, the magnetic conductive outer frame has a specific structure and is provided with a cooling pipe, and the magnetic conductive outer frame is further provided with a connecting plate, a heat-resistant adhesive layer, a connecting assembly, an auxiliary cooling assembly and the like. The application solves the problems of uneven magnetic field and easy loss of magnetism, and improves the uniformity and reliability of cooling when the magnetism is lost.

The invention relates to a method for improving fluidity of magnetic powder and preparing a high-consistency magnet, belongs to the technical field of rare earth permanent magnet material preparation, and solves the problem of low performance and density consistency of a sintered neodymium-iron-boron magnet caused by poor fluidity of the magnetic powder, non-uniform pressing density and sintering deformation in the prior art. The method comprises the following steps: optimizing a jet milling process and controlling the granularity of magnetic powder to be 2.4-3.0 microns; the preparation method comprises the following steps of: mixing powder in a mixer filled with inert shielding gas and loaded with hard magnetic grinding particles by adopting a composite additive which is divided twice and has the total amount of 0.18-0.22% and the ratio of (1.5-2): 1 so as to improve the flowability and morphology consistency of the magnetic powder; orientation pressing with the magnetic field not smaller than 2T is adopted, variable-speed segmented pressing and pressure maintaining are executed, and the density of the green body reaches 4.0-4.4 g / cm < 3 >; and finally, through auxiliary low-temperature sintering and two-stage tempering treatment, the heating / cooling rate is controlled not to exceed 4 DEG C / min. The high-uniformity sintered neodymium-iron-boron magnet with the residual magnetism Br consistency superior to 0.4% and the density consistency superior to 0.2% is prepared, and the method is suitable for batch production of high-end equipment.

This invention relates to the field of molding press technology, and more particularly to a pulsed magnetic field molding press and molding method. The equipment includes a pulsed electromagnet, molding components, and a pulse control circuit, etc. A high-intensity pulsed magnetic field is generated by capacitor discharge to achieve rapid orientation of magnetic powder. Compared with traditional DC magnetic field molding, this invention can significantly shorten the charging and demagnetizing time and improve pressing efficiency. The mold uses a combination of magnetic and non-magnetic materials to optimize the magnetic field distribution. Demagnetization is achieved through reverse pulses, avoiding the influence of residual magnetism. This invention is suitable for one-time molding of magnets with a single unit weight ≤300g, simplifying the process and improving production efficiency and product quality.

A current sensor (1) for detecting magnetism generated by a conductor (51) in which a current flows in a first direction (D1), the current sensor (1) comprising: a magnetic detection unit (2) capable of detecting magnetism, a first magnetic shield (3) and a second magnetic shield (4); wherein the first magnetic shield (3) comprises a first shielding section (31) and two continuous second shielding sections (32) each located near two ends (31E) of the first shielding section (31); the second magnetic shield (4) comprises a third shielding section (41) and two continuous fourth shielding sections (42), each located near two ends (41E) of the third shielding section (41); the first shielding section (31) and the third shielding section (41) are positioned such that they are opposite each other and essentially parallel to each other; a conductor placement area (5) is provided between the first shielding section (31) and the third shielding section (41), wherein the conductor placement area (5) is an area in which the conductor (51) is placed such that the first direction (D1) is substantially parallel to the first shielding section (31); near the two ends (31E) of the first shielding section (31) in a second direction (D2) which is orthogonal to the first direction (D1), the two second shielding sections (32) are continuous in the direction of the second magnetic shielding (4) and are substantially parallel to a third direction (D3) which is orthogonal to the first direction (D1) and the second direction (D2); near the two ends (41E) of the third shielding section (41) in a second direction (D2) which is orthogonal to the first direction (D1), the two fourth shielding sections (42) are continuous in the direction of the first magnetic shielding (3) and are substantially parallel to the third direction (D3) which is orthogonal to the first direction (D1) and the second direction (D2); the length (W31) of the first shielding section (31) along the second direction (D2) is greater than the length (W41) of the third shielding section (41) along the second direction (D2); the magnetic detection unit (2) is arranged between the first shielding section (31) and the conductor placement area (5); and the magnetic detection unit (2) is provided at a magnetic field cancellation position where the residual magnetic field remaining in the first magnetic shield (3) and the second magnetic shield (4) in the second direction (D2) is essentially zero at times when no current is applied, after a prescribed current has flowed in the conductor (51), with respect to the length (H42) of the two fourth shield sections (42) along the third direction (D3).

The invention relates to the technical field of high-quality stainless steel processing, and particularly discloses a diamagnetic low-conductivity stainless steel strip for an electronic element and a preparation method of the diamagnetic low-conductivity stainless steel strip. The stainless steel strip comprises, by mass, 0.06%-0.10% of C, 14%-20% of Mn, 16%-18% of Cr, 4.0%-6.5% of Ni, 0.02%-0.06% of Nb, 0.01%-0.03% of Ti, smaller than or equal to 0.003% of S, smaller than or equal to 0.04% of P, smaller than or equal to 20 ppm of O, 0.08%-0.20% of N, smaller than or equal to 1 ppm of H and the balance Fe and inevitable impurities. The preparation method comprises the steps of EAF primary smelting, AOD refining, RH vacuum circulation degassing refining, continuous casting, hot rolling, cold rolling, annealing, self-adaptive pickling, precise leveling and the like. By accurately regulating and controlling the components of C, Mn, Cr, Ni, Nb and Ti and matching with EAF-AOD-RH refining, hot rolling three-stage controlled cooling, gradient annealing and other processes, the low magnetic conductivity (mu 25 is smaller than or equal to 1.002 H / m) of the strip in the wide temperature range of-40 DEG C to 125 DEG C is achieved, the tensile strength reaches 680 MPa, the ductility reaches 45%, the surface Ra is smaller than or equal to 0.02 micrometer, the requirements for magnetism resistance, high strength, high corrosion resistance and precision machining of electronic elements are met, and the industrial adaptability is high.

A method for monitoring the state of health and / or correct functioning of an elastomeric component, the method comprising the steps of: (a.) providing the elastomeric component, the elastomeric component comprising a matrix of elastomer material and homogenously dispersed magnetic particles; (b.) providing a magnetic sensor element for measuring magnetic properties of the elastomeric component with the dispersed magnetic particles, wherein the sensor is positioned in or near the elastomeric component; (c.) measuring magnetic properties of the elastomeric component with the dispersed magnetic particles; (d.) based on the measurements of the magnetic properties of step c.: (i.) determining mechanical properties of the elastomeric component related to strain of the elastomer matrix, a temperature effect on magnetism influenced by the magnetic particles or structural changes of the magnetic particles within the elastomer matrix due to humidity; (ii.) correlating the mechanical properties with the state of health and / or the proper functioning of the elastomeric component.

The utility model particularly relates to an inductance type displacement sensor, a magnetic suspension bearing system and a compressor, the inductance type displacement sensor comprises a stator and at least two sensor coil assemblies, the stator is of an annular structure, and the at least two sensor coil assemblies are arranged on the inner circle of the stator and are arranged along the inner circumference of the stator at intervals. The sensor coil assembly comprises a first magnetic pole and at least one second magnetic pole set, each second magnetic pole set comprises two second magnetic poles, the two second magnetic poles in each second magnetic pole set are symmetrically arranged on the two opposite sides of the first magnetic pole in the inner circumferential direction of the stator, and the magnetism of the second magnetic poles is opposite to that of the first magnetic pole. According to the inductance type displacement sensor, the number of the magnetic poles is arranged to be an odd number such as three or five, so that the magnetic field of the stator yoke part can be effectively improved, the magnetic field distribution is more uniform, and the problems of over-high magnetic density and large magnetic resistance of the existing inductance type displacement sensor can be solved.

This invention relates to the field of iron ore beneficiation technology and discloses a method for preparing efficient roasting and separation of refractory iron ore, comprising the following steps: S1, raw material pretreatment and pre-enrichment: refractory weakly magnetic iron oxide ore is crushed, and a dry separation method is used to pre-remove some low-grade waste rock to obtain pre-enriched rough concentrate; S2, intelligent grinding and drying; S3, magnetized roasting; S4, rapid quenching and stabilization of roasted ore. This invention, through rapid cooling (quenching) combined with an atmosphere protection process, stabilizes and solidifies the magnetism of the magnetized roasting product—magnetite—avoiding magnetic loss due to subsequent processing, providing a high-magnetic, stable feed for subsequent weak magnetic separation operations, which is a prerequisite for ensuring a high magnetic separation recovery rate; through strong magnetic separation to ensure recovery rate, combined with intelligent flotation to improve concentrate grade, a deep cleaning process is formed, achieving refined separation of complex roasting products, maximizing both the total iron metal recovery rate and concentrate grade simultaneously.

This utility model belongs to the field of wastewater treatment equipment, specifically relating to a high-gradient magnetic separation device, including a flocculation reaction tank, a magnetic field separation box, a sludge tank, and a clear water tank connected by pipes; the flocculation reaction tank is located above the magnetic field separation box, and the sludge tank and clear water tank are located below the magnetic field separation box; the magnetic field separation box is equipped with a stainless steel wool layer, and electromagnets are installed at the upper and lower ends of the magnetic field separation box, with rectifiers connected to the electromagnets; wastewater containing heavy metal ions is first mixed with the magnetic flocculation composite material in the flocculation reaction tank and stirred, and then flows into the magnetic field separation box under gravity. The rectifier applies a magnetic field to the upper and lower ends of the magnetic field separation box. Under the action of the magnetic field, the non-magnetic part is discharged into the clear water tank through the gaps in the stainless steel wool layer, while the magnetic part is captured in the stainless steel wool layer. After the magnetism is deactivated, the magnetic part enriched in the stainless steel wool layer flows into the sludge tank, thereby achieving the effect of sludge-water separation.

Magnetism of each layer of two magnetic layers having different coercive forces and forming a magnetic tunnel junction of a memory cell of an MRAM is inspected with high accuracy in a state of being covered with a nonmagnetic body before wiring. An inspection device includes: an NVC probe in which diamond having an NVC is set at a tip, the NVC being a composite impurity defect formed of a pair of nitrogen substituting for carbon in a diamond lattice and a vacancy from where a carbon atom adjacent to the substitution nitrogen is removed; and a pulse magnetic field applying unit. The pulse magnetic field applying unit executes an applying step of applying a pulse magnetic field to a magnetic body in a sample, and the NVC probe executes a detection step of detecting a magnetic field from the magnetic body when application of the pulse magnetic field by the pulse magnetic field applying unit is stopped.

The invention discloses a neodymium-iron-boron magnet and a preparation method and application thereof. The neodymium-iron-boron magnet is provided with a non-parallel magnetic circuit; the neodymium-iron-boron magnet is in a curved surface shape, and the cross section of the neodymium-iron-boron magnet is in a circular arc shape; wherein any position of the same cross section meets the following formula; wherein B0 is the surface magnetism at the center of the arc; theta is an angle formed by any position of the arc and the center line of the arc; b (theta) is a surface magnet at a position corresponding to theta; theta max is an angle formed by the two ends of the arc and the center line of the arc; and alpha satisfies 0.8 < = alpha < = 1. The neodymium-iron-boron magnet has a non-parallel magnetic circuit and also has uniform surface magnetic distribution and high residual magnetism; after the motor is actually used for a permanent magnet motor, the motor efficiency can be improved, and the sound pressure level is reduced.

The invention discloses a preparation method for improving the initial permeability of permalloy, which is based on Fe-Ni-Mo permalloy and adopts a ternary synergistic process of electron beam smelting, ultra-large cold rolling deformation and magnetic field heat treatment. The permalloy strip with the ultrahigh initial permeability is prepared through the method, three microscopic barriers including an impurity pinning barrier, a grain boundary and defect barrier and an intrinsic magnetic barrier which limit the magnetic performance of permalloy are overcome, the permalloy strip with the ultrahigh initial permeability is obtained, and the method has the advantages of being simple in process, low in cost, easy to produce in batches and the like, and can well meet the requirements of high-end electromagnetic elements.