1077 results about "Magnetic powder" patented technology

The application relates to the technical field of integrally-formed inductors, in particular to a moisture-resistant soft magnetic composite material and a preparation method thereof and an integrally-formed inductor. The moisture-resistant soft magnetic composite material comprises the following components by mass: 100 parts of soft magnetic powder, 2-5 parts of a resin bonding agent and silicon resin, wherein the mass ratio of the silicon resin to the resin bonding agent is (0.3-2.0):100. The moisture-resistant soft magnetic composite material can avoid the phenomenon of explosion of the integrally-formed inductor during a reflow soldering process after moisture absorption.

The invention discloses a nondestructive flaw detection method in a seamless steel tube production process, which comprises the following steps of: initially acquiring a seamless steel tube image, quickly judging whether a crack exists or not, quickly detecting and judging a seamless steel tube product, positioning the crack position of the seamless steel tube according to the initially acquired seamless steel tube image, and spraying dry magnetic powder. Therefore, the seamless steel tube image data after spraying of the dry magnetic powder is collected for the second time, and the edge contour information of clearer magnetic traces at crack positions in the seamless steel tube image data is extracted. And finally, classifying the cracks and generating accurate pixel-level masks of the cracks by adopting a crack classification model. Inputting the cracks into a preset crack generation fault table in a classified manner to inquire fault generation steps and equipment in the seamless steel pipe production process; and the staff can quickly check faults and complete repair according to the inquired and output fault generation steps and equipment in the seamless steel pipe production process, so that the production recovery of the seamless steel pipe production line is accelerated.

The invention relates to the technical field of magnetic material injection molding, and discloses an injection molding magnetic powder orientation optimization method and system based on rheology-magnetic field coupling. The method comprises the following steps: deploying a distributed sensing network at key positions of a mold runner and a mold cavity, and synchronously capturing dynamic viscosity change gradient and magnetic field intensity space distribution of a melt in real time in a filling process. The captured data are input into a multi-physics field coupling simulation engine based on micromechanics, an instantaneous orientation vector field of the magnetic powder in the cavity is obtained through calculation, then an orientation order degree topological graph is constructed through tensor analysis and an image algorithm, and a weak orientation area and the boundary of the weak orientation area are accurately recognized. And finally generating a composite regulation and control instruction of the magnetic field and the injection parameters according to an identification result. According to the method, online diagnosis and active compensation regulation and control of the orientation state of the magnetic powder can be realized, and the orientation uniformity and consistency of the injection molding magnet are improved.

The invention discloses a visual tactile sensor, an electronic skin and a robot, relates to the field of sensors, and is used for improving the comprehensiveness and sensitivity of stress detection. The sensor comprises a magnetic film covering the top surface and the side surface, and the magnetic film is prepared by mixing magnetic powder and silicone rubber; the support supports the magnetic thin film, a magnetic display card and a light source are arranged in the support, the visual touch collector collects magnetic induction data and development data of stress of the magnetic thin film, and then the multi-mode pressure detection model analyzes the stress position and / or the stress size. The stress detection sensitivity is high, comprehensive detection of the top face and the side faces can be achieved, and the detection precision is high.

The invention relates to the technical field of magnetic powder inspection detection, and discloses a petroleum pipeline weld joint on-line detection device based on magnetic powder inspection, which comprises a flaw detector body internally provided with an electromagnetic yoke device for generating a magnetic field and a contact roller rotatably arranged at the bottom of a support leg of the flaw detector body, and a mounting groove is formed in the bottom surface of the flaw detector body. A fixing rod is fixedly arranged on the inner wall of the mounting groove, a telescopic rod is elastically arranged on the rod wall of the fixing rod, a sealing cylinder is fixedly arranged on the bottom face of the telescopic rod, two guide wheels used for positioning a welding seam are arranged at the bottom of the sealing cylinder, and elastic touch plates are fixedly arranged on the opposite faces of the two guide wheels; and a pressure adjusting assembly is arranged in the mounting groove. According to the equipment, the physical track of the weld joint is actively used as an automatic tracking mechanism of the flaw detector body, so that the detection sensitivity of the equipment to the weld joint is effectively improved.

The invention belongs to the technical field of preparation of soft magnetic composite materials, and particularly relates to an insulation coating method and application of a soft magnetic powder material. The insulating coating method comprises the following steps: (1) uniformly mixing low-melting-point metal or alloy powder with silica sol, a silane coupling agent and a thermocuring resin glue solution to obtain coating slurry; and (2) uniformly mixing soft magnetic powder with the coating slurry obtained in the step (1), firstly performing hot-pressing curing molding at the temperature of 60-100 DEG C under a vacuum condition, and then performing hot-pressing sintering treatment at the temperature higher than the melting point temperature of low-melting-point metal or alloy powder and under an oxygen-containing atmosphere condition to obtain the insulated and coated soft magnetic powder material. According to the insulating coating method, the advantages of an organic material insulating coating method and an inorganic material insulating coating method are combined, the defects of the organic material insulating coating method and the inorganic material insulating coating method are overcome, and the stability and the insulating coating effect of the insulating coating layer are remarkably improved.

The invention belongs to the technical field of soft magnetic materials, and particularly relates to a high-permeability low-loss FeSiAl magnetic powder core and a preparation method and application thereof. The preparation method comprises the following steps: (1) uniformly mixing pure Al powder with organic silica sol, an aluminate coupling agent, a lubricant and an organic binder to obtain coated bonding slurry; and (2) uniformly mixing FeSiAl soft magnetic powder with the coating and bonding slurry obtained in the step (1), carrying out hot-pressing curing molding at the temperature of 60-100 DEG C under a vacuum condition, and then carrying out hot-pressing sintering treatment at the temperature of 750-1000 DEG C under an oxygen-containing atmosphere condition to obtain the FeSiAl magnetic powder core with high magnetic conductivity and low loss. The FeSiAl soft magnetic powder is subjected to insulation coating and bonding treatment by adopting the coating and bonding slurry with specific composition, the high-frequency loss of the obtained magnetic powder core can be reduced by combining a specific treatment process, and the influence on the magnetic conductivity is relatively small.

The invention discloses a phased array, TOFD and magnetic powder integrated detection system and method for medium and large diameter pipeline welded joints, the detection system comprises a control system, a liquid storage and supply system and a scanning system, the control system is connected with the liquid storage and supply system, the control system is connected with the scanning system, and the scanning system is connected with the control system. The liquid storage and supply system is connected with the scanning system through a flexible water pipeline and a flexible magnetic suspension pipeline; the liquid storage and supply system comprises a magnetic suspension tank and a water tank which are respectively used for storing magnetic suspension and water; the scanning system is a data acquisition center, is provided with a phased array probe, a TOFD probe, an electromagnetic yoke and a video sensor in a centralized mode, operates in a sub-control mode, is driven by a magnetic attraction wheel driving mechanism to achieve automatic scanning of a welding joint, and transmits detection data information to the control system. The device is compact in structure, convenient for later maintenance and low in manufacturing cost; according to the invention, the parameter control is accurate, the detection data can be analyzed in real time, the data interpretation is convenient, the detection precision is high, the detection speed is fast, and safety and reliability are realized.

The invention belongs to the related technical field of high-speed permanent magnet disc type motors, and provides a preparation method of a high-speed permanent magnet disc type motor and a gradient hierarchical composite rotor in order to solve the limitation of an existing axial disc type motor under the working condition of ultrahigh rotating speed, the high-speed permanent magnet disc type motor comprises a stator iron core, a winding and the gradient hierarchical composite rotor; the gradient hierarchical composite rotors are symmetrically distributed on the two sides of the stator core. The gradient hierarchical composite rotor comprises a gradient hierarchical composite magnetic circular ring, a circular ring pressing plate and a rotor yoke magnetic conductive ring; the gradient hierarchy composite magnetic ring is formed by winding gradient hierarchy composite magnetic strips, the gradient hierarchy composite magnetic strips are composed of magnetic powder resin mixed colloid and carbon fiber strips, and the thickness of the magnetic powder resin mixed colloid is decreased in a gradient mode in the radial direction. According to the scheme, the mechanical strength of the high-speed disc type permanent magnet motor rotor is enhanced, the eddy current loss of the rotor is reduced, and the rotor forming flexibility is improved.

The invention discloses a 2: 17 type rare earth soft magnetic / Fe-based soft magnetic laminated composite material and a preparation method thereof. The method sequentially comprises the following steps: 1) screening 2: 17 type rare earth soft magnetic powder, performing insulation coating, mixing with polyurethane, and performing magnetic field orientation to obtain a thin ring green body; (2) Fe-based soft magnetic powder is sieved and mixed with polyurethane, and then a thin ring green body is obtained through magnetic field orientation; (3) alternately stacking the 2: 17 type rare earth soft magnetic thin ring green bodies and the Fe-based soft magnetic thin ring green bodies in the direction perpendicular to the plane of the thin ring green bodies; and 4) carrying out hot press molding on the laminated soft magnetic composite material. Based on the high-frequency characteristic of the 2: 17 type rare earth soft magnetic material and the high magnetic conductivity characteristic of the Fe-based soft magnetic material, collaborative optimization of the magnetic conductivity and the cut-off frequency is achieved within the ultra-wideband range from MHz to GHz, the problem that the magnetic conductivity of a traditional soft magnetic composite material is attenuated along with the frequency is effectively solved, high-frequency loss is greatly reduced, and the service life of the soft magnetic composite material is prolonged. And a solution is provided for high-frequency soft magnetic components (such as inductors and transformers) with high magnetic performance and low power consumption.

The invention relates to the technical field of inductors, in particular to a preparation method of an integrally-formed inductor containing nano-diamond alkene, which comprises the following preparation methods: S1, preparing a heat dissipation material, preferably a nano-diamond alkene material; s2, preparing magnetic powder, uniformly mixing the raw powder, adding a dispersing agent, a surfactant and a heat dissipation material in the mixing process to obtain soft magnetic powder particle cores, and sieving the soft magnetic powder particle cores to obtain sieved soft magnetic powder particle cores; s3, preparing a composite insulating layer, uniformly mixing a first solution, a heat dissipation material and the sieved soft magnetic powder particle cores, volatilizing, removing, heating and drying to form a coating layer I, and coating the outer surfaces of the soft magnetic powder particle cores with the coating layer I; s4, a bonding insulating layer is prepared, a second solution and the soft magnetic powder in the step S3 are evenly mixed and volatilized to be removed, then heating and drying are carried out, a second coating layer is formed to coat the outer surface of the first coating layer, resin is crosslinked through heating curing, a firm composite insulating shell layer containing nano diamond alkene is formed, the composite insulating layer has heat dissipation performance and pressure resistance, and the bonding insulating layer is formed. Wherein the nano-diamond alkene can be interconnected with the nano-diamond alkene in the magnetic powder to achieve a better heat dissipation effect, the bonding insulating layer is mainly used for increasing the bonding force between the magnetic powder, the heat dissipation performance of the magnetic powder is conveniently improved, the inductor short circuit is reduced, and the service life of the inductor is prolonged.

A nanocrystalline alloy soft magnetic powder contains: impurities; and a composition represented by a composition formula FeaCubNbc(Si1-x(B1-yCry)x)100-a-b-c-dSd represented by an atomic ratio, where a, b, c, d, x, and y satisfy 75.5≤a≤79.5, 0.3≤b≤2.0, 2.0≤c≤4.0, 0.001≤d≤0.080, 0.55≤x≤0.91, and 0≤y≤0.185. The nanocrystalline alloy soft magnetic powder has crystal grains having a crystallite diameter of 1.0 nm or more and 30.0 nm or less, a particle diameter D10 is 7.0 μm or more and 15.0 μm or less, and a particle diameter D50 is 22.0 μm or more and 32.0 μm or less.

The invention discloses a high-insulativity coating treatment method of a metal soft magnetic composite material, which belongs to the technical field of metal soft magnetic materials, and comprises the following steps: firstly, performing vacuum dehydration treatment on metal soft magnetic powder, and controlling the moisture content to be not higher than 0.1%; carrying out ultrasonic dispersion treatment on the boron nitride nanosheets to form a suspension, and modifying the magnesium borate nanowires and a silane coupling agent for later use; preparing an inorganic coating solution and an organic coating solution; activating the powder in the fluidized bed by adopting radio frequency plasma of argon-oxygen mixed gas; enabling the activated powder to enter a three-fluid nozzle fluidized bed reactor, and implementing synchronous spray coating in two stages: in the first stage, spraying inorganic coating liquid and applying pulse plasma to form a composite bottom layer; in the second stage, spraying organic coating liquid and carrying out ultraviolet precuring to form a resin layer; and the coated powder is treated by a stepped thermocuring procedure to obtain a finished product. The technical problem of how to improve the insulation coating performance of the metal soft magnetic composite material is solved.

This invention proposes a metal soft magnetic powder core with excellent low-frequency magnetic properties and its preparation method, belonging to the field of magnetic materials. Using at least nano-boron powder and iron-silicon soft magnetic alloy powder as raw materials, high-temperature diffusion and high-temperature nitriding treatments are employed. Part of the nano-boron powder forms a high-resistivity iron-silicon-boron permeation layer on the surface of the iron-silicon soft magnetic alloy powder, while some nano-boron powder forms a boron nitride insulating layer with both high resistivity and high thermal stability between the iron-silicon soft magnetic alloy powders, effectively controlling eddy currents. Hot pressing further increases the density of the metal soft magnetic powder core, reduces the demagnetizing field, thereby improving permeability and reducing hysteresis loss. Thus, excellent low-frequency magnetic properties of high density, high permeability, and low loss are simultaneously obtained in the metal soft magnetic powder core.

The utility model discloses an axle gear magnetic powder inspection device which comprises a lathe bed, a movable support module is arranged on one side of the top end of the lathe bed, a fixed support module is arranged on the other side of the top end of the lathe bed, a guide rail is fixedly installed on the surface of the top end of the lathe bed, and an opening and closing coil module is arranged on the surface of the top end of the guide rail. A rotating magnetic field magnetizing shell is arranged on one side of the opening and closing coil module, a rotating magnetic field magnetizing module is arranged in the rotating magnetic field magnetizing shell, and the axle is movably installed on the surface of the top end of the lathe bed. Through the cooperation of the opening and closing coil module and the rotating magnetic field magnetization shell, when the device is used, the position of the opening and closing coil module can be adjusted by moving the movable base on the surface of the guide rail, so that magnetic powder inspection operation can be performed on each position on the surface of an axle, and the device can be conveniently used for axles with different lengths.

A method for preparing a highly oriented anisotropic bonded magnet belongs to the field of magnetic material preparation technology. The preparation method is as follows: First, a binder is dissolved in a solvent to form a homogeneous and stable solution. Then, surface-pretreated anisotropic magnetic powder is added to the solution. Next, the magnetic powder / binder solution is placed in a ball mill jar for ball milling to refine the powder, ensuring uniform dispersion and achieving better calendering orientation anisotropy. Finally, an extractant is added while vacuum filtering the ball-milled suspension, causing the magnetic powder / binder composite to precipitate as a pre-oriented precipitate. The precipitate is crushed, sieved, and then calendered. During calendering, the pre-oriented magnetic powder / binder composite undergoes further mechanical orientation, thereby preparing an anisotropic bonded magnet with a higher degree of orientation.

The invention relates to the field of distance measurement, and particularly discloses a detection reagent card shell adaptability detection system, which is used for detecting a detection reagent card shell filled with magnetic powder, and comprises a matrix type magnetic field detection module, a processing module and a magnetic field imaging module, the matrix type magnetic field detection module comprises a substrate and magnetic field sensors, the magnetic field sensors are fixed on the substrate in an array mode, and the magnetic field sensors are used for collecting magnetic field intensity signals at different positions in the plane of the outer side of the to-be-detected reagent card shell and converting the magnetic field intensity signals into electric signals to be output; the processing module is used for getting close to the to-be-detected reagent card shell after the matrix type magnetic field detection device is started. By the adoption of the technical scheme, key information such as the actual fitting degree, pressing force distribution and local gaps of the internal test strip and the card shell can be obtained, and the specific position of the assembly problem can be accurately positioned.

A method for making an iron-based oxide magnetic powder includes adding raw material solution containing trivalent iron ions, or trivalent iron ions and ions of a metal element that partially substitutes Fe sites, and an alkaline aqueous solution for neutralizing the raw material solution to a reaction system to adjust the pH of the reaction system to 1.0 or higher and 3.0 or lower. Hydroxycarboxylic acid is added to the obtained reaction solution and thereafter the pH of the reaction system is neutralized to 7.0 or higher and 10.0 or lower. The obtained precipitate of a substituent metal element-containing iron oxyhydroxide is coated with silicon oxide and then heated, whereby an iron-based oxide magnetic powder is obtained with a reduced content of fine and coarse particles, a particle shape close to a perfect sphere, and particles of ε-iron oxide in which Fe sites are partially substituted by other metal elements.

The invention belongs to the technical field of electromagnetic wave absorbing materials, and discloses a composite coating with electromagnetic protection and explosion-proof functions as well as a preparation method and application of the composite coating. The coating comprises 40 to 60 parts of polycarbodiimide modified diphenylmethane diisocyanate, 40 to 60 parts of a semi-prepolymer which is synthesized from polycarbonate diol with the equivalent weight of 1000 and has the NCO content of 10 to 20 percent, 73 to 100 parts of a polyether amine curing agent, 15 to 20 parts of diethyl toluenediamine or dimethyl thio toluenediamine, 0.5 to 2 parts of calcium carbonate and 3 to 6 parts of magnetic powder. And the two components are quickly reacted and molded through a spraying process. According to the invention, the polyurea elastomer is used as a matrix, so that the coating is endowed with excellent impact resistance, explosion-proof characteristics, water impermeability, oil resistance, low temperature resistance and other environmental tolerance; meanwhile, an adjustable electromagnetic wave absorption function is realized by doping specific magnetic powder. The coating is simple in preparation process and excellent in comprehensive performance, and is particularly suitable for equipment surfaces with high requirements on stealth and survival protection, such as oil storage equipment.

The utility model relates to the technical field of inductors, and particularly discloses a duplex-winding coupling inductor which comprises an inductor body made of magnetic powder, a first coil, a second coil, two first electrode plates and two second electrode plates. The first coil and the second coil are wound together, the two first electrode plates are connected with the two ends of the first coil respectively, and the two second electrode plates are connected with the two ends of the second coil respectively; the inductor body wraps the first coil and the second coil, the two first electrode plates and the two second electrode plates extend out of the inductor body and extend to the bottom face of the inductor body, the two first electrode plates are located at one set of opposite angles of the bottom face of the inductor body, and the two second electrode plates are located at the other set of opposite angles of the bottom face of the inductor body. According to the utility model, the magnetic circuit can be prolonged, and the two electrode plates connected with the same coil are not easy to be short-circuited.

The invention provides an inductor based on iron-based nanocrystalline powder and a preparation method of the inductor. The inductor is provided with an I-shaped main body, a coil and a wrapping part wrapping the I-shaped main body and the coil; wherein the I-shaped main body comprises a core column and a platform part which extends from the core column to two ends and is provided with a groove, the coil comprises a winding part which is wound on the core column and a fixing part which extends outwards from the winding part and is arranged in the groove, and the surface of the fixing part is flush with the surface of the platform part and is exposed; the I-shaped main body is a mixture of iron-based nanocrystalline powder and high-temperature organic silicon epoxy resin, the wrapping part is a mixture of magnetic powder and high-temperature organic silicon epoxy resin, specifically, the iron-based nanocrystalline powder is adopted as the material of the I-shaped main body, the I-shaped inductor has the advantages of being high in inductance value and low in loss, allowing larger current to pass through and being unsaturated and suitable for high-power scenes, and meanwhile, the high-power inductor has the advantages of being high in inductance value and low in loss. And a coating material adopts high-molecular-weight high-temperature organic silicon epoxy resin, so that the product strength is higher, and the production efficiency and the preparation yield are effectively improved.

This application belongs to the field of nondestructive testing technology, specifically relating to an automated method and device for wet magnetic particle inspection and identification of weld areas in drill pipes, aiming to solve the problem of insufficient automation in weld area inspection and identification of drill pipes. This application includes: acquiring magnetic trace images of the surface of the weld area of ​​the drill pipe; processing the magnetic trace images based on a preset image analysis model to identify abnormal regions in the magnetic trace images; comparing the abnormal regions with pre-established defect feature information to determine whether the abnormal regions are defective regions; if the abnormal regions are determined to be defective regions, obtaining the spatial coordinates of the defective regions in the drill pipe cylindrical surface coordinate system based on the position of the defective regions in the image coordinate system; and controlling the rotation of the drill pipe based on the spatial coordinates to position the defective regions at a marking station for automatic marking. This ensures the stability and reliability of the inspection quality, effectively avoids missed detections and false judgments, and solves the problem of insufficient automation in existing equipment.

This invention relates to a neodymium iron boron (NdFeB) magnet and its preparation method, comprising the following steps: providing NdFeB pre-formed magnetic powder; mixing the NdFeB pre-formed magnetic powder with alloy powder to obtain a mixed powder, and subjecting the mixed powder to hot pressing sintering and hot deformation treatment to obtain the NdFeB magnet. The alloy powder contains at least one of Cu or Al elements, heavy rare earth elements, light rare earth elements, and Ga elements, with the atomic percentage of heavy rare earth elements in the alloy powder being less than or equal to 45%. This preparation method can improve the utilization rate of heavy rare earth elements, thereby effectively improving the coercivity and temperature stability of the iron boron magnet with less heavy rare earth elements, thus reducing the amount of heavy rare earth elements used and lowering the raw material cost of the NdFeB magnet.

An Sm-Fe-N-based sintered magnet comprising a sintered body of a magnetic material containing an Sm-Fe-N-based magnetic powder and a Zn-Al alloy powder, wherein the Al content of the Zn-Al alloy powder is 6-84 atom%, and the open porosity of the sintered magnet is not more than 15%.

The application belongs to the technical field of magnetic material preparation, and particularly relates to a production process of high-performance rare earth permanent ferrite magnetic powder. The process comprises the following steps: preparing iron red and auxiliary materials, wherein the auxiliary materials comprise calcium carbonate, strontium carbonate, lanthanum oxide and cobalt oxide; mixing raw materials in proportion, then performing dry ball milling to obtain mixed materials; performing steam treatment on the obtained mixed materials to make the water content of the mixed materials reach 2-5%, then performing ripening, and the ripening time is at least 30 min, and the ripening process is completed in the screw conveyor; balling; pre-sintering; performing coarse crushing on the pre-sintered materials and sieving to obtain rare earth permanent ferrite magnetic powder. Through steam pretreatment and ripening, the strength and thermal stability of the ball materials are significantly improved, the ball materials remain complete in the kiln, the flowability is good, and the consistency and qualified rate of the product are improved.

The present disclosure provides a magnetic material that can achieve an improvement in the gap-filling properties of a product made from the magnetic material, an improvement in the magnetic permeability of the product, and an improvement in the withstand voltage of the product. The magnetic material comprises a first magnetic powder and a second magnetic powder. The 50% particle size based on the volume-based particle size distribution of the first magnetic powder is greater than the 50% particle size based on the volume-based particle size distribution of the second magnetic powder. The 50% particle size based on the volume-based particle size distribution of the first magnetic powder is 5.5-16.5 μm. The 90% particle size based on the volume-based particle size distribution of the first magnetic powder is not more than 31 μm.

This invention discloses a low-leakage, high-stability magnetic sludge biochar adsorbent, its preparation method, and its application, comprising the following steps: S1: preparing a sludge biochar matrix from dewatered sludge; S2: mixing the sludge biochar matrix obtained in step S1 with nano-magnetic powder, and performing high-energy ball milling under an inert atmosphere to obtain a composite powder with a physically interlocked structure, thereby preparing the low-leakage, high-stability magnetic sludge biochar adsorbent. This invention provides a structurally stable, high-adsorption-performance, and environmentally friendly magnetic sludge biochar adsorbent that can effectively remove polyether ionocarrier antibiotics (such as maduramycin) from water, showing promising practical application prospects and environmental benefits.

The invention discloses a real object test block and method for calibrating magnetic particle inspection sensitivity of a locomotive axle, the test block is made of the axle, the test block is provided with sections B, C, D, E, F, G, H, I, J, K and L and an end face A, four longitudinal defect holes with the diameter of 1mm and the hole depth of 8mm are formed in the end face A, the section B, the section C, the section D and the section E, and the four longitudinal defects are equally arranged at 90 degrees in the circumferential direction; four longitudinal defects formed in the F section are arranged at intervals of 36 degrees in the circumferential direction; the H section, the I section, the J section, the K section and the L section are each provided with four transverse defect holes with the diameter of 1 mm and the hole depth of 8 mm, the four transverse defects are equally arranged at 90 degrees in the circumferential direction, and the four transverse defects formed in the G section are arranged at the intervals of 60 degrees in the circumferential direction. According to the physical test block and the method for calibrating the magnetic powder inspection sensitivity of the rolling stock axle, provided by the invention, the accuracy of magnetic powder sensitivity calibration is improved.

The invention relates to the field of sewage treatment reagents, in particular to a composite alkaline carbon source for sewage treatment and a preparation method thereof.The preparation method comprises the following steps that S1, magnetic microwave pretreatment and magnetic powder recovery are conducted, and pretreated sludge is obtained; s2, performing alkaline fermentation to obtain a fermentation product; s3, carrying out solid-liquid separation and deep removal of nutritive salt to obtain a suspension; s4, refining the fermentation liquor to obtain an alkaline carbon source crude product; and S5, compounding and curing the carbon source to obtain the composite alkaline carbon source. The composite alkaline carbon source for sewage treatment is prepared, a traditional combination of sodium acetate and sodium carbonate is replaced, solid waste utilization is achieved, and the proportion of nitrogen, phosphorus and heavy metal elements is small.

The application discloses a composite patch for promoting hair growth, a hair growth cap and a preparation method. The composite patch for promoting hair growth comprises the following raw materials in parts by weight: medical grade liquid silicone 40-60 parts, gelatin 20-35 parts, silane coupling agent 1-2 parts, far infrared ceramic powder 1-2 parts, tourmaline powder 1-2 parts, chisel stone powder 0.5-1.5 parts and neodymium-iron-boron magnetic powder 4-6 parts. The composite patch for promoting hair growth is prepared by selecting the raw materials, so that the composite patch has the functions of radiating far infrared, generating a micro electric field and a magnetic field and having weak negative electric characteristics at the interface to improve the directional migration of calcium ions, thereby achieving the purposes of improving the micro environment of hair follicles and promoting hair growth.