272 results about "Magnetic orientation" patented technology

A magnetic alignment system can include a primary annular magnetic alignment component and a secondary annular magnetic alignment component. The primary alignment component can include an inner annular region having a first magnetic orientation, an outer annular region having a second magnetic orientation opposite to the first magnetic orientation, and a non-magnetized central annular region disposed between the primary inner annular region and the primary outer annular region. The secondary alignment component can have a magnetic orientation with a radial component. Additional features, such as a rotational magnetic alignment component and / or an NFC coil and circuitry can be included.

The invention provides a geomagnetic compensation and bias magnetic field generation system and method for cold atom interference. The system comprises a triaxial magnetometer, a triaxial Helmholtz coil, a voltage-controlled current source and an FPGA regulation and control module. The three-axis magnetometer is used for collecting space magnetic field data at a plurality of monitoring positions in the space where the three-axis Helmholtz coil is located in real time; the FPGA regulation and control module is used for calculating control voltage data required by the voltage-controlled current source according to a target magnetic field and any space magnetic field data collected by the three-axis magnetometer in each sampling period, controlling coil current transmitted to the three-axis Helmholtz coil, and outputting the coil current to the three-axis Helmholtz coil. And loop iteration is carried out until the three-axis Helmholtz coil generates a target magnetic field at a plurality of monitoring positions, wherein the target magnetic field is a near-zero magnetic field in the X / Y direction, and the magnetic field intensity in the Z direction is constant and is a non-zero value. The device can respond to the change of the environmental magnetic field in real time, and provides a stable and accurate magnetic field environment for the cold atom interference test on the basis of compensating the influence brought by the geomagnetic field.

A first winding is wound around a first middle column of a first magnetic core, and a second winding is wound around a second middle column of a second magnetic core. The third magnetic core is located between the first winding and the second winding, the third magnetic core has a through hole, and both the first middle column and the second middle column extend into the through hole. When a direction of a magnetic field generated by the first winding is the same as a direction of a magnetic field generated the second winding, the first magnetic core and the second magnetic core generate common-mode inductance. When a direction of a magnetic field generated by a third winding is opposite to a direction of a magnetic field generated a fourth winding, the third magnetic core generates differential-mode inductance.

This invention discloses a passive shimming method based on the displacement of a shimming plate, comprising the following steps: determining a set of shimming plate distribution information using a passive shimming method, including the initial installation position of the shimming plate, the spatial dimensions of the shimming plate, and the shimming plate itself; after installing the shimming plate, measuring the magnetic field distribution information on the surface of the target area, including the magnetic field values ​​of the main magnetic field direction components and the spatial position information of the measurement points; based on the shimming plate distribution information and the magnetic field distribution information, establishing an optimization problem, including a weighted objective function for magnetic field deviation and the total displacement of the shimming plate, and constraints determined based on magnetic field uniformity and the maximum displacement of the shimming plate; solving the optimization problem to obtain the displacement of the shimming plate, and operating the target shimming plate based on the displacement. This invention effectively compensates for shimming errors through the displacement of the shimming plate, avoiding excessive use of the shimming plate during the shimming iteration process.

The invention belongs to the field of magnetic materials. The invention provides a preparation method of a rare earth permanent magnet, which comprises the following steps: weighing rare earth magnetic powder, adding a binder solution, uniformly mixing, and drying until a solvent is completely volatilized to obtain bonded magnetic powder; the bonded magnetic powder is placed in a die cavity of a constant-temperature die for heat preservation and preheating; an inner cavity of the constant-temperature mold is vacuumized to form a vacuum environment, and gas adhering to gaps of the magnetic powder is exhausted; applying a magnetic field to the mold, forming an oriented magnetic field in the mold cavity, arranging easy magnetization axes of the magnetic powder along the direction of the oriented magnetic field, and applying pressing force to obtain a mold pressing blank; and heating and curing the molded green body to obtain the rare earth permanent magnet. The rare earth permanent magnet prepared through the preparation method has high compactness, the residual magnetism and the maximum magnetic energy product capacity of the permanent magnet are improved, rare earth magnetic powder is prevented from being oxidized, and the coercive force of the permanent magnet is remarkably improved.

The invention discloses a high-temperature pipeline magnetostrictive guided wave sensor and a monitoring method, and relates to the field of ultrasonic nondestructive testing. According to the sensor, a wrinkled iron-cobalt alloy belt is used as a sensitive element, and the sensor is in dry coupling contact with a to-be-detected pipeline; the high-temperature-resistant static magnetic field coil is wound on the outer side of the aluminum pre-tightening ring in a solenoid mode, and a bias pulse excitation mode is adopted. Alternately winding the bottom end of the wrinkle structure of the wrinkle-type ferrocobalt alloy belt and the back surface of the belt material, controlling the wrinkle-type ferrocobalt alloy belt to excite a guided wave signal in a pulse section, and receiving the guided wave signal in a bias section; the dynamic magnetic field and the static magnetic field generated by the two groups of coils are perpendicular in direction, and torsional mode guided waves are generated in the high-temperature pipeline based on the reverse Weidmann effect. The sensor is easy to install and stable in performance, the whole structure is resistant to high temperature for a long time, and the engineering problem of high-temperature failure is solved. The method provided by the invention comprises the steps of optimizing pre-tightening force, pulse voltage and bias current parameters, so that the transduction efficiency is improved, and the capability of detecting new defects of the pipeline in high-temperature and variable-temperature states is enhanced.

The application discloses a method for preparing a metal organic framework film by magnetic field induction regulation control. The method comprises the following steps: vertically immersing a sheet carrier into a film forming solution of the metal organic framework film; placing a container provided with the film forming solution and the carrier into a uniform magnetic field; and standing for 4-24 hours to obtain the metal organic framework film prepared by the magnetic field induction regulation control. The metal organic framework film is a cobalt-based, nickel-based or iron-based metal organic framework film. The carrier material comprises alumina, porous carbon and porous organic material. The magnetic field direction is perpendicular to or parallel to the surface of the carrier. The metal organic framework film prepared by the application has excellent gas separation performance, and the film forming process is simple, convenient, easy to enlarge and popularize.

The invention discloses an ultrafast terahertz response magnetic field measurement method and system based on a linear magneto-optical conversion material, and the method comprises the steps: preparing a linear magneto-optical conversion heterojunction film which comprises at least one signal generation layer with a linear magneto-optical conversion characteristic and at least one signal emission layer with a strong spin-orbit coupling effect; placing the heterojunction thin film at the position of a magnetic field to be measured, and irradiating the heterojunction thin film by using femtosecond laser pumping pulse so as to enable the heterojunction thin film to radiate a terahertz signal; through the terahertz vector detection and rotation detection system, the positive and negative and the magnitude of terahertz signals radiated by the heterojunction film in three groups of orthogonal directions are detected, and the magnetic field direction and the magnitude of the magnetic field position to be detected are calculated based on the three groups of terahertz signals. The sensor has the advantages of being high in sensitivity, high in response speed, non-contact and the like, can achieve rapid detection of various vector magnetic fields such as stable, periodic modulation and sub-picosecond transient pulse, and has hundred-nanometer-scale spatial resolution capacity.

The invention discloses a dry type reactor turn-to-turn short circuit fault positioning method based on a magnetic field direction angle. Obtaining radial and axial magnetic field component data of an outer side designated area under different working conditions; dividing a measurement area according to a reactor structure and magnetic field distribution characteristics; screening optimal measurement areas under different working conditions based on the divided measurement areas and initial moment magnetic field components in the obtained radial and axial magnetic field component data; calculating a magnetic field direction angle of the optimal measurement area under different screened working conditions; making a sensor layout scheme according to the calculated magnetic field direction angles of the optimal measurement area under different working conditions and the change characteristics of the magnetic field direction angles of the measurement points under different working conditions, and determining each measurement point; fault positioning is realized by analyzing the magnetic field direction angle difference between the short-circuit working condition and the normal working condition of each measuring point. According to the method, the problems of insensitive response to the turn-to-turn short circuit fault of the inner layer encapsulation and low positioning precision of a traditional method are solved, and a high-reliability technical scheme is provided for fault detection of the dry-type air-core reactor.

The invention provides a self-excited cesium optical pump atomic magnetometer and a magnetic field measurement method. The magnetometer comprises a physical probe part and a circuit part. The physical probe part comprises a cesium spectrum lamp, an optical element, a cesium atom absorption gas chamber, a radio frequency coil and a photoelectric detector; the circuit part comprises a photoelectric conversion circuit, a phase-locked amplification circuit and a radio frequency excitation circuit modulated by square waves. A macroscopic magnetic moment is generated by pumping cesium atoms through left-handed circularly polarized light, a radio frequency magnetic field induces Larmor precession, light intensity changes are detected and fed back to a radio frequency coil to form self-oscillation, and the external magnetic field intensity is calculated according to the linear relation between oscillation frequency and the magnetic field. Square wave modulation is adopted to broaden the measurement bandwidth, a magnetic field direction adjusting system is additionally arranged to automatically keep an angle of 45 degrees between an optical axis and a magnetic field so as to eliminate a blind area, the hemisphere automatic switching function is achieved, and the advantages of being high in sensitivity, fast in response, high in adaptability, small in size and low in power consumption are achieved.

A memory device includes a spin-orbit-transfer (SOT) bottom electrode, an SOT ferromagnetic free layer, a first tunnel barrier layer, a spin-transfer-torque (STT) ferromagnetic free layer, a second tunnel barrier layer and a reference layer. The SOT ferromagnetic free layer is over the SOT bottom electrode. The SOT ferromagnetic free layer has a magnetic orientation switchable by the SOT bottom electrode using a spin Hall effect or Rashba effect. The first tunnel barrier layer is over the SOT ferromagnetic free layer. The STT ferromagnetic free layer is over the first tunnel barrier layer and has a magnetic orientation switchable using an STT effect. The second tunnel barrier layer is over the STT ferromagnetic free layer. The second tunnel barrier layer has a thickness different from a thickness of the first tunnel barrier layer. The reference layer is over the second tunnel barrier layer and has a fixed magnetic orientation.

The invention provides a vector magnetic field detection method based on a surface acoustic wave magnetic field directivity model, and the method employs an external magnetic field to act on a magnetic sensitive film on a sound propagation path to generate a dynamic magnetoelastic coupling effect, modulates the propagation characteristics of surface acoustic waves, and carries out the decoupling of a sound signal, and obtains the magnetic field information. The response value of the sensor is influenced by the included angle between the direction of the external magnetic field and the anisotropic axis, so that the angle orientation of the sensor in the space and the size and direction of the magnetic field can be quantitatively calibrated by projecting the magnetic field to be measured in the space into a coordinate system of the sensor, and a surface acoustic wave magnetic field directivity model is constructed. The surface acoustic wave magnetic field sensing technology has the advantages of high sensitivity, quick response and the like, and the vector magnetic field detection method can realize the direction positioning function of a full-plane magnetic field and has important practical value in the application field of space vector magnetic field detection.

The invention discloses a dry-type air-core reactor turn-to-turn short circuit fault detection method and system based on magnetic field direction angle change, and the method comprises the following steps: firstly, obtaining a plurality of operation conditions of a dry-type air-core reactor, including a normal operation condition and a turn-to-turn short circuit fault condition containing different short circuit positions; time sequence magnetic field vector data of a measurement point position is preset on the outer side; secondly, calculating a magnetic field direction angle of each measurement point according to the acquired data, and drawing a time sequence change curve of the magnetic field direction angle under a corresponding working condition; and finally, comparing the time sequence curves of the magnetic field direction angles of the measuring points under different working conditions, and judging whether a turn-to-turn short circuit fault occurs or not based on the deviation degree characteristics of the magnetic field direction angles of the turn-to-turn short circuit working condition and the normal operation working condition, thereby completing fault diagnosis. The weak magnetic field characteristic of turn-to-turn short circuit can be sensitively captured, the limitation of a traditional monitoring method is effectively overcome, and a powerful guarantee is provided for stable operation of the dry-type air-core reactor.

The invention provides a magnetic resonance guided charged particle beam radiotherapy device and an electromagnetic navigation parameter debugging method for target coordinates, and belongs to the technical field of radiotherapy devices. The system comprises a charged particle beam electromagnetic navigation device which comprises multiple stages of electromagnetic navigation coils, charged particle beams sequentially pass through the multiple stages of electromagnetic navigation coils, and parallel charged particle beams consistent with a magnetic resonance main magnetic field in direction are generated; the MR imaging device comprises an MR main magnetic field coil upper group and an MR main magnetic field coil lower group, and an imaging treatment area is formed between the MR main magnetic field coil upper group and the MR main magnetic field coil lower group. The electromagnetic navigation parameter debugging method comprises the steps of constructing a target cost function, optimizing electromagnetic navigation parameters based on an optimization algorithm without gradient information, and determining and outputting optimal navigation parameters. According to the invention, the charged particle beam parallel to the MR main magnetic field can be generated, the influence of Lorentz force on the charged particle beam is greatly reduced, the difficulty of positioning a tumor target region by the charged particle beam under the guidance of MR can be reduced, and the treatment accuracy is improved.

This application relates to an ion cyclotron antenna device, including a controller; a detection component electrically connected to the controller, the detection component being used to detect the direction of the magnetic field in real time; a rotating device electrically connected to the controller; and an ion cyclotron antenna connected to the rotating device. When the direction of the magnetic field changes, causing the magnetic field direction to no longer be perpendicular to the ion cyclotron antenna, the detection component immediately feeds back a signal to the controller. The controller compares the relative positional relationship between the antenna and the magnetic field, and then outputs a command to the rotating device, enabling the rotating device to drive the ion cyclotron antenna to rotate and adjust, so that the ion cyclotron antenna is once again perpendicular to the direction of the magnetic field. Through the coordinated work of the detection component, the rotating device, and the controller, the relative perpendicularity between the ion cyclotron antenna and the direction of the magnetic field can always be guaranteed, thereby effectively suppressing the generation of parallel electric fields, reducing the generation of sheath potential, reducing the impact of high-energy particles on the antenna, and extending the steady-state operation time of the antenna and the nuclear fusion device.

To more easily heat an armature by induction heating.SOLUTION: A jig used when inductively heating a heated body by passing current through an induction coil, the jig is positioned between the induction coil and the heated body when viewed from the direction of current flow through the induction coil, the jig has a non-magnetized region and a magnetized region that can be magnetized by a magnetic field generated by passing current through the induction coil, the non-magnetized region is positioned on a straight line passing through the induction coil and the heated body when viewed from the direction of current flow, and the magnetized regions is provided on one side and the other side of the non-magnetized region in a direction along the magnetic field.SELECTED DRAWING: Figure 1

The invention discloses a magnetic generator based on magnetic bias current, and belongs to the technical field of generators, the magnetic generator comprises a casing, a rotating shaft and a stator, the rotating shaft is provided with a plurality of fan-shaped iron cores and fan-shaped permanent magnets, the fan-shaped iron cores and the fan-shaped permanent magnets are distributed on the rotating shaft along the circumference, the fan-shaped iron cores and the fan-shaped permanent magnets are symmetrically arranged, the fan-shaped iron cores are provided with armature windings, and the armature windings are arranged on the stator. The stator comprises four fan-shaped permanent magnets which are opposite in polarity and symmetrically distributed at the two ends of the machine shell, and the four fan-shaped permanent magnets form an axial magnetic pole pair. According to the technical scheme, the iron core and the permanent magnets are arranged in the rotor, the direction of the magnetic field of the permanent magnets is opposite to the direction of an induced magnetic field generated by an armature winding of the iron core, and the induced magnetic field hinders rotation of the rotor; meanwhile, magnetic circuit performance is optimized through magnetic biasing current, starting energy consumption is reduced, and efficient power generation is achieved through the synergistic effect of the permanent magnet and the induced magnetic field.

The utility model provides an embedded self-fixing anti-theft isolation type permanent magnet shielding directional magnetic conduction induction button. The button comprises a button fixing shell and a movable inner core. The movable inner core is installed on the button fixing shell through an elastic assembly in a rebounding mode. A shielding piece is arranged on the inner wall of the lower cavity of the movable inner core; a neodymium magnet is installed in the center of a lower cavity of the movable inner core through the shielding piece in an embedded mode. The button fixing shell is provided with embedded reverse teeth; the button fixing shell is mounted on the control panel through the embedded reverse teeth; a vacuum bidirectional magnetic switch is arranged below the embedded reverse teeth; and after a magnetic field generated by the neodymium magnet is isolated by the shielding piece, the neodymium magnet attracts the vacuum bidirectional magnetic switch in a directional manner to enable the vacuum bidirectional magnetic switch to act. According to the utility model, the direction of the magnetic field generated by the neodymium magnet can be accurately controlled, the accuracy and reliability of button operation are ensured, and the possible interference of disordered diffusion of the magnetic field on peripheral electronic components is avoided.

The invention discloses a bearing retainer production mold demagnetization device, and belongs to the field of mold demagnetization. The positioning bearing platform is fixedly arranged on the supporting rack and is used for bearing a bearing retainer production mold to be demagnetized; the full-coverage dynamic demagnetization module comprises a demagnetization coil assembly capable of linearly moving along the supporting rack, the demagnetization coil assembly moves to the position of the positioning bearing platform, and the magnetic field range of the demagnetization coil assembly can completely cover the geometric contour of the mold to be demagnetized; the demagnetization control unit is electrically connected with the demagnetization coil assembly and the demagnetization power supply, and is configured to trigger the demagnetization power supply to output an alternating magnetic field with preset parameters when the demagnetization coil assembly moves to completely cover the mold, and the alternating magnetic field has a constant amplitude and the direction of the alternating magnetic field is periodically reversed; and meanwhile, when the demagnetizing coil assembly reversely moves to be away from the mold by a preset distance, the demagnetizing current is attenuated to zero, and demagnetizing in a mode that the mold is away from the mold and attenuated is combined is achieved.

The invention discloses a light collimator based on magnetic particles and low-melting-point glass and a manufacturing method thereof. The manufacturing method comprises the following steps: uniformly mixing a low-melting-point glass raw material and the magnetic particles; the melting point of the low-melting-point glass is 300 DEG C to 500 DEG C; placing the obtained mixture in a heating device, and controlling the heating temperature to be within the melting point range of the low-melting-point glass raw material and to be lower than the Curie temperature of the magnetic particles; then adding a dispersing agent; pouring the uniformly mixed solution into a mold, and placing the mold in a uniform magnetic field with an unchanged magnetic field direction, so that the magnetic particles are arranged into a plurality of chain-shaped aggregates parallel to the magnetic field direction under the action of the magnetic field, and the chain-shaped aggregates are parallel to one another; and after complete cooling and solidification, the magnetic field effect is removed, and the optical collimator based on the magnetic particles is manufactured. Therefore, the technical problems that an existing optical collimator is poor in high temperature resistance and corrosion resistance and limited in light-transmitting wave band are solved.

The utility model discloses a vibration absorption damping device for a gear box, which comprises a gear box base, a damping mechanism and a lubricating mechanism, the gear box base is fixedly connected with a gear box upper cover, and the gear box base is provided with a first rotating shaft, a second rotating shaft and a third rotating shaft. The damping mechanism is arranged in the gearbox base; according to the vibration absorption damping device for the gear box, vibration is detected through a sensor, current is adjusted through a PLC, the magnetic field intensity is adjusted by changing the current of a magnet exciting coil, and magnetic particles in magnetorheological fluid in gaps can be arranged in the magnetic field direction to form a chain-shaped or columnar structure through the magnetic field intensity; according to the magnetorheological fluid damping device, the viscosity of the magnetorheological fluid is increased, so that damping force is generated, vibration energy is converted into heat energy and consumed, noise generated by vibration is reduced, the working environment of workers is improved, and the noise is effectively prevented from affecting physical and psychological health of the workers.

The present invention discloses a high spatial resolution magnetic Barkhausen noise (MBN) sensor and measurement method, which belongs to the field of micromagnetic non-destructive testing technology. The magnetic Barkhausen noise (MBN) non-destructive testing method is adopted to avoid destructive operations such as grinding and polishing the material surface and pickling, thereby realizing the measurement of the material grain boundary position and grain boundary inclination angle. First, through an innovative horseshoe-shaped yoke design, by optimizing the yoke structure and precisely processing its tip air gap, the preparation of a high spatial resolution MBN sensor is realized. Then, by utilizing the difference between the grain boundary position of ferromagnetic materials and the magnetic signals inside the grains, through plane scanning and eigenvalue extraction, it is possible to accurately distinguish between the interior of the grains and the grain boundary area, and realize the positioning of the grain boundary position. At the same time, a magnetic field rotation method is introduced to accurately measure the inclination angle of the grain boundary by comparing and analyzing the MBN signals under different magnetic field directions. The device and method effectively improve the measurement efficiency of microstructures such as grain boundaries of ferromagnetic materials.

The invention relates to a connecting device (3) comprising a first connecting element (1, 2) and a second connecting element (1, 2), wherein - the two connecting elements (1, 2) are shaped so that they engage in a form-fitting manner in a closed position (S) and can be separated from one another by displacement relative to one another along an opening direction (O), wherein relative movements of the connecting elements (1, 2) to one another from the closed position (S) in directions other than the opening direction (O) are blocked by the form-fitting of the connecting elements (1, 2), - the first connecting element (1, 2) has a locking magnet (6) which is movable back and forth between a predetermined unlocking position and a predetermined locking position along a locking direction (R), and is arranged such that its magnetic field direction is oriented transversely to the locking direction (R), - one of the connecting elements (1, 2) has a holding element (7) which is positioned such that, at least in the closed position (S), it exerts a force on the locking magnet (6) so that it tends towards the locking position, - the two connecting elements (1, 2) are shaped so that the locking magnet (6) blocks a relative movement of the connecting elements (1, 2) to each other from the closed position (S) along the opening direction (O) in the locking position and does not block it in the unlocking position, - one of the connecting elements (1, 2) has on its outer side a key area (B) above the unlocking position, which is shaped so that a magnet with an adhesive force of less than 1000 g and a magnetic field aligned coaxially and parallel to the magnetic field of the locking magnet (6) in the unlocking position can pull the locking magnet into the unlocking position and hold it there. Furthermore, the invention comprises a connection system.

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 disclosure provides a magnetoresistive quadrant detector for use in a magnetic sensing device comprising a magnetic multi-turn sensor and an angle turn sensor, in particular, an angle sensor configured to provide 180° absolute angle measurements, such as an anisotropic magnetoresistive (AMR) angle sensor. The quadrant detector is formed of at least two magnetoresistive elements, preferably giant magnetoresistive (GMR) elements, which may be integrated to the multi-turn sensor die or provided on a separate die within the sensor package. The magnetoresistive elements are configured to provide a unique combination of resistance states for each quadrant of magnetic field direction. This quadrant information can then be used to remedy any ambiguities in the multi-turn measurement without needing 360° absolute angle information from the single turn angle sensor.

The invention provides a neodymium iron boron magnet and a preparation method thereof. The method comprises the following steps: obtaining neodymium iron boron magnetic powder; the neodymium iron boron magnetic powder is put into the mold, and the neodymium iron boron magnetic powder is in a loose loading state in the mold; applying an alternating-current oscillation attenuation magnetic field to the neodymium-iron-boron magnetic powder in the mold; orientation profiling is conducted in a preset orientation static magnetic field, a pressed blank is obtained, and the magnetic field direction of the preset orientation static magnetic field is perpendicular to the magnetic field direction of the alternating-current oscillation attenuation magnetic field; and post-processing the pressed blank to obtain the neodymium-iron-boron magnet. The magnetic field is attenuated through alternating-current oscillation, the magnetic field direction is perpendicular to the static magnetic field direction, agglomeration of the magnetic powder can be scattered, and meanwhile the influence of non-parallel magnetic lines of the magnetic field on magnetic powder orientation can be reduced.

The invention discloses a three-dimensional magnetic control space optical switch device which comprises a first electromagnet (1), a second electromagnet (2), a third electromagnet (3), a first light source (4), a second light source (5), a third light source (6), a first collimating mirror (7), a second collimating mirror (8), a third collimating mirror (9), a three-dimensional magnetic fluid cavity (10), a first converging mirror (11), a second converging mirror (12), a third converging mirror (13), a first light intensity decision device (14), a second light intensity decision device (15) and a third light intensity decision device (16). The light intensity transmissivity of a light beam transmitted into the magnetic fluid along the direction of the magnetic field is increased along with the increase of the external magnetic field within a certain range, when the light intensity transmissivity reaches a certain value, the light path of the light beam is determined to be on, otherwise, the light path is off, the magnetic field intensity generated by the three electromagnets is respectively adjusted, and the on-off of the three light paths can be realized. The optical switch has strong environmental adaptability and light noise interference resistance, and has good application potential in the technical field of optical communication and optical sensing.

Provided is a notebook computer in which desired resonance frequency and characteristics can be easily achieved with respect to a magnetic field antenna disposed so as to overlap with a palm rest of a case. A notebook computer is provided with: a case which includes a palm rest and is foldable; a magnetic field antenna that generates a magnetic field and is housed in the housing so as to overlap the palm rest in the magnetic field direction in which the magnetic field is generated; and a metal plate part that is disposed so as to overlap the magnetic field antenna in the magnetic field direction and that adjusts the resonance frequency of the magnetic field antenna, in which a hole pattern is formed, the hole pattern including at least one hole, and the metal plate part is disposed so as to overlap the magnetic field antenna in the magnetic field direction. And an eddy current suppression unit that suppresses an eddy current generated at the metal plate section due to the magnetic field generated by the magnetic field antenna.

Disclosed are a winding apparatus and a winding method, the winding apparatus includes: a winding needle, being configured to wind a winding material; a power supply assembly, being configured to be electrically coupled to the winding needle, so as to form current on an axis of the winding needle; and a magnet supply assembly, being configured to provide a magnetic field to the winding needle, a magnetic field direction intersecting the axis of the winding needle so that the winding needle generates an ampere force for resisting a deformation of the winding needle in the magnetic field when the winding material is wound. By the above method, the present application may reduce the deformation of the winding needle, reduce a defective rate of a winding product formed by the winding of the winding material, and improve quality of the winding product.