969 results about "Saturation (magnetic)" patented technology

The invention belongs to the technical field of soft magnetic materials, and discloses an amorphous nanocrystalline soft magnetic material with high saturation flux density and a preparation method thereof. The preparation method comprises the following steps that an iron-based amorphous strip is crushed into flat powder with the thickness being 5-25 microns and the diameter being 30-80 microns, and scaly amorphous soft magnetic powder is obtained; the method comprises the following steps: performing insulation coating treatment on spherical iron-silicon soft magnetic powder with the average particle size of 2-20 microns to obtain insulation coating modified spherical magnetic powder; and mixing the obtained scaly amorphous soft magnetic powder, the insulating coated modified spherical magnetic powder and bonding resin, performing compression molding, performing annealing crystallization treatment at the temperature of 450-550 DEG C, and then raising the temperature to 600-900 DEG C for sintering treatment to obtain a finished product. According to the amorphous nanocrystalline soft magnetic material and the preparation method thereof, the spherical iron-silicon soft magnetic powder modified through insulation coating is compounded with the scaly amorphous soft magnetic powder, and low loss is maintained while the obtained amorphous nanocrystalline soft magnetic material Bs is remarkably improved.

The invention discloses an anti-direct-current component nanocrystalline current transformer and a using method thereof. The anti-direct-current component nanocrystalline current transformer comprises a current transformer body, and a magnetic core hole penetrating front and back is formed in the middle of the front side of the current transformer body. The device is provided with a secondary side open circuit detection and protection mechanism, so that imbalance of a magnetic field in the mutual inductor caused by disconnection of a secondary loop is effectively prevented, iron core magnetic flux saturation and potential high electromotive force generation are avoided, the safety of the mutual inductor and peripheral equipment is protected, the risk of power system faults such as fire disasters or short circuits is reduced, and meanwhile, the safety of the mutual inductor is improved. A live wire centering fixing mechanism is arranged, so that the stable centering position of a wire in a magnetic core hole of the mutual inductor is ensured, magnetic field distribution is optimized, the magnetic leakage phenomenon is reduced, the accuracy and stability of current measurement are remarkably improved, meanwhile, measurement fluctuation caused by wire shaking is reduced, and the measurement precision is improved. And more accurate data support is provided for harmonic analysis, fault detection and electric energy quality monitoring of a power system.

The invention belongs to the field of microwave communication, and relates to a double-frequency microstrip circulator based on multi-layer material nesting, and the circulator comprises a substrate, a magnetic conductive sheet, a high dielectric ceramic, a high dielectric constant ferrite ring, a high magnetic saturation ferrite, a circuit layer, a ceramic sheet, and a permanent magnet. The magnetic conductive sheet is arranged at the bottom of the base body, the high-dielectric ceramic is arranged on the magnetic conductive sheet, the high-dielectric-constant ferrite ring is annularly embedded in the high-dielectric-constant ceramic, and the high-magnetic-saturation ferrite is embedded in the high-dielectric-constant ferrite ring. The circuit layer is arranged on the substrate consisting of the high dielectric ceramic, the high dielectric constant ferrite ring and the high magnetic saturation ferrite, the ceramic chip is arranged on the circuit layer, and the permanent magnet is arranged on the ceramic chip. The overall size is small, weight is light, and reliability is high; the working frequency range is wide, through different transformations, the system is not easily detected by enemies, the confidentiality is high, and the anti-interference capability is strong; the method can be widely applied to the fields of mobile communication, satellite communication, radar detection, electronic countermeasures and the like.

The invention relates to a high-frequency and high-performance iron-nickel alloy magnetic powder core and a preparation method and application thereof, belongs to the field of metal magnetic powder cores, and solves the problems that in the prior art, when a metal magnetic powder core is applied at high frequency, high magnetic conductivity, high magnetic conductivity stability and high quality factor are difficult to consider, and the saturation flux density is low. And the preparation process is tedious. The invention discloses a preparation method of a high-frequency high-performance iron-nickel alloy magnetic powder core. The preparation method comprises the following steps: S1, preparing raw materials; s2, performing pretreatment; s3, the pretreated iron-nickel alloy powder and nano SiO2 powder are blended, and inorganic insulation coating powder is obtained; s4, adding the inorganic insulating coating powder into a first coating agent to obtain inorganic and first organic insulating coating powder; s5, adding the inorganic and first organic insulation coating powder into a second coating agent to obtain inorganic and double-layer organic insulation coating powder; and S6, compression molding. The comprehensive magnetic performance of the iron-nickel magnetic powder core is improved, and the preparation process is simplified.

The invention provides a composite ferrite circulator and electronic equipment, the composite ferrite circulator comprises a first bias magnetic circuit assembly, a ceramic gasket, a composite material substrate and a second bias magnetic circuit assembly which are sequentially arranged along a first direction, and one side, close to the ceramic gasket, of the composite material substrate is provided with a microstrip circuit; one side, close to the second bias magnetic circuit assembly, of the composite material substrate is provided with a grounding metal layer, the composite material substrate comprises a ceramic dielectric substrate, the surface of the ceramic dielectric substrate is provided with a cylindrical ferrite penetrating along the first direction, and the outer side of the cylindrical ferrite is sequentially sleeved with a plurality of circular ring ferrites; the saturation magnetization intensity of the cylindrical ferrite and the saturation magnetization intensity of the circular ferrite are sequentially reduced from inside to outside. According to the scheme, a higher relative bandwidth of the circulator can be realized, and the non-reciprocal transmission performance of the circulator is improved, so that the overall working performance of the electronic equipment is improved.

The invention discloses a method for characterizing the pore size of the full pore diameter of shale based on combined measurement of a gravimetric method and NMR. The method comprises the following steps: drawing a curve that the pore distribution frequency of a rock sample changes along with the pore diameter; calculating the saturated water porosity of the rock sample based on the weight of the dried rock sample and the weight of the saturated rock sample; based on the saturated water porosity of the rock sample, converting the nuclear magnetic semaphore of the nuclear magnetic resonance T2 spectrum after saturation treatment of the rock sample into a porosity component; based on the porosity component, drawing a change curve of the porosity component and the porosity accumulated value along with the relaxation time T2 after saturation treatment of the rock sample; calculating a space-time conversion coefficient between the nuclear magnetic resonance relaxation time T2 value and the pore size; and based on the space-time conversion coefficient, drawing a full-aperture pore size result graph after saturation treatment of the rock sample on the basis of the change curve of the porosity component and the porosity accumulated value along with the relaxation time T2 after saturation treatment of the rock sample. The phenomenon that the measurement ranges of the pore sizes are overlapped does not exist through multiple simultaneous measurement means, and the obtained full-aperture pore size result is higher in precision.

The invention belongs to the technical field of magnetic functional materials, and particularly relates to a nanocrystalline magnetically soft alloy and a preparation method and application thereof. The invention provides a nanocrystalline soft magnetic alloy which comprises the following chemical components: Fe, Si, B, Nb, Cu, P and rare earth metal, and the rare earth metal is selected from at least one of Nd and Sm. According to the nanocrystalline magnetically soft alloy, a proper amount of rare earth metal is added, the ferromagnetic coupling exchange effect between ordered phases of the nanocrystalline magnetically soft alloy is improved, so that the magnetic induction intensity and the high-frequency magnetic conductivity of the nanocrystalline magnetically soft alloy are both improved, the magnetic conductivity of the nanocrystalline magnetically soft alloy at 100 kHz can reach 42000 or above, and the high-frequency magnetic conductivity of the nanocrystalline magnetically soft alloy at 100 kHz can reach 42000 or above. Meanwhile, the saturation flux density reaches up to 1.75 T or above, and the coercive force is as low as 0.8 A / m.

The invention relates to a Fe-Si-Nb-B-Cu-Er amorphous alloy and a preparation method and application thereof, and belongs to the technical field of metal materials. The atomic percent expression of the Fe-Si-Nb-B-Cu-Er amorphous alloy disclosed by the invention is (Fe < 83 > Si < 3 > Nb < 4 > B < 9 > Cu < 1 >) < 100-x > Er < x >, wherein x is equal to 3.5 to 4.5. The rare earth element Er is added to optimize the soft magnetic performance of a Fe-Si-Nb-B-Cu amorphous alloy system, the coercive force of the Fe-Si-Nb-B-Cu amorphous alloy system is reduced, the preparation method is simple and easy to implement, and the Fe-based amorphous alloy with the excellent soft magnetization performance is obtained. The magnetization intensity of the amorphous alloy is sharply increased along with increase of a magnetic field under a low magnetic field and then gradually reaches saturation, typical soft magnetic performance is presented, and the amorphous alloy has wide application space in the field of magnetic materials.

The invention discloses an iron-based nanocrystalline soft magnetic alloy and a preparation method thereof. A magnetically soft alloy strip is prepared through smelting and a single-roller melt-spinning method, stress relief annealing is carried out on the magnetically soft alloy strip through assistance of a magnetic field, and then crystallization annealing treatment is carried out. Different from a traditional method for regulating and controlling the magnetic performance of the alloy through precipitation of a large number of nanocrystals, the method only induces precipitation of a very small number of nanocrystals, and high saturation flux density and low coercive force can be obtained while the toughness of the strip is ensured; the iron-based nanocrystalline soft magnetic alloy with high saturation flux density and low coercive force can be prepared by taking Fe as a main element, Co element with the atomic fraction lower than 8%, Cu element with the atomic fraction lower than 1% and at least one of oxygen, sulfur, phosphorus, carbon, silicon, boron and the like as other trace elements.

The invention discloses a stator assembly, a compressor and refrigeration equipment, and relates to the technical field of motors. The stator assembly comprises a stator core formed by stacking a plurality of amorphous alloy sheets, the stator core comprises a yoke part, a tooth part and a shoe part, and the stator core is formed by stacking a plurality of amorphous alloy sheets, so that the iron loss of the stator assembly can be reduced. For a motor, the area of a stator slot is expected to be as large as possible to increase the winding wire diameter so as to reduce copper loss, and the smaller the minimum width of a tooth part is, the better is, but the smaller the width of the tooth part is, the more likely to cause magnetic field saturation. In order to reasonably design the minimum tooth width of the tooth part so as to reduce the problem of magnetic voltage drop increase caused by magnetic field saturation, the minimum tooth width Wt of the tooth part is set in a range of 2piD / 9Q to 2piD / 3Q, so that the area of the stator slot can be effectively increased, the problem of magnetic voltage drop increase caused by magnetic field saturation can be improved, the magnitude of current can be reduced, and the service life of the stator slot can be prolonged. The working efficiency of the motor is improved.

The invention relates to a magnetic saturation evaluation method and system for a magnetic component in a strong magnetic field environment, and the method comprises the steps: constructing a target component model of a to-be-tested magnetic component according to a target geometric parameter and a target material parameter, and respectively setting excitation and boundary conditions of the target component model according to the target working current parameter and the target working environment magnetic field parameter, and performing simulation. The method comprises the following steps: acquiring simulated BH data of a target position in a target component model and corresponding simulated working environment magnetic induction intensity, and determining that the target component model reaches a magnetic saturation state according to the simulated BH data of the target position; and taking the corresponding simulated working environment magnetic induction intensity as a simulated saturated external magnetic field threshold value of the to-be-tested magnetic component. According to the embodiment of the invention, analog simulation of the saturation external magnetic field threshold of the to-be-tested magnetic component in the magnetic field environment is realized, and important support can be provided for model selection application and design optimization of the magnetic component in the high-intensity magnetic field environment.

A smart variable inductor based on magnetorheological materials comprises an "EE"-shaped iron core, two DC control coils, one AC coil, and a magnetorheological material gap. The magnetorheological material gap is located on the central column of the "EE"-shaped iron core. The two DC control coils and the AC coil are wound around the two side columns and the central column of the "EE"-shaped iron core, respectively. By controlling the DC current in the DC control coil, the magnetic saturation of the side columns can be changed, thus achieving intelligent wide-range adjustment of the inductance of the AC coil. The beneficial effects of this patent are: the provided smart variable inductor based on magnetorheological materials, due to the higher permeability of magnetorheological materials than air, which decreases with increasing magnetic field strength, has advantages such as a wide inductance adjustment range and low diffusion flux. When used in LLC resonant converters, it can achieve intelligent wide-range adjustment of input / output voltage and load, as well as intelligent current sharing control in multi-parallel converters.

Magnetic saturation detectors for power converters are presented herein. An energy transfer element has an input power winding wrapped around a center post. Single or multiple transverse windings are positioned perpendicular to the input power winding and coupled to receive a transverse current that provides a transverse magnetic flux density within the energy transfer element. The transverse magnetic flux density produces a transverse voltage waveform. A voltage detection circuit is configured to receive the transverse voltage waveform and detect a change in the sign of the slope of the transverse voltage waveform. The change in the sign of the slope indicates magnetic saturation. The voltage detection circuit is configured to detect an occurrence of an extremum in the transverse voltage waveform. The extremum indicates the change in the sign of the slope.

The invention relates to the technical field of soft magnetic materials, in particular to an iron-based amorphous alloy strip, a preparation method of the iron-based amorphous alloy strip, an amorphous alloy iron core and a transformer. The iron-based amorphous alloy strip is composed of main elements of Fe, Si, B and C and inevitable impurities. Nicks distributed at intervals are formed in the surface of the iron-based amorphous alloy strip; the iron-based amorphous alloy strip has B80 / BS > = 0.96, where B80 / BS is the ratio of the magnetic flux density B80 generated when an external magnetic field of 80 A / m is applied to the iron-based amorphous alloy strip to the saturation magnetic flux density BS of the iron-based amorphous alloy strip. According to the amorphous iron-based alloy strip disclosed by the invention, the effective component proportion is combined with the strip for nicking, B80 can be effectively improved, the magnetic density design space of a transformer iron core is improved, the soft magnetic performance is improved, and meanwhile, a transformer has relatively low noise and no-load loss.

The invention discloses a defect detection system based on a bias alternating current magnetization modulation TMR sensor, and the system is characterized in that through the cooperation of an alternating current and direct current magnetization module, a TMR sensor and a defect prediction module, the alternating current and direct current magnetization module is used for simulating an alternating current and direct current superimposed magnetic field test environment, and a reverse alternating current and direct current magnetic saturation magnetic field is formed; the TMR sensor obtains defect signal characteristics of a to-be-detected workpiece and sends the obtained defect signal characteristics of the to-be-detected workpiece to the defect prediction module, and the defect prediction module achieves full-scale detection of defects from 20 micrometers to millimeter by analyzing peak values (micron-scale narrow defects) and waveform widths (millimeter-scale defects) of alternating-current waveforms. The balance of high sensitivity and wide range of the same sensor is realized, and meanwhile, the dual requirements on precision and efficiency in actual detection are met. Meanwhile, through alternating current and direct current magnetic field cooperative modulation, the measuring range TMR sensor is expanded to 300 Gs, and the full range from weak magnetic leakage to strong magnetic leakage is covered.

The invention belongs to the field of hard alloy materials, and provides a modified high-performance non-magnetic hard alloy and a preparation process thereof. The surface of a WC particle is chemically plated with a Ni-P-B-Cr-Cu amorphous shell layer, and a binding phase is converted into Ni3P and Ni3B nanophase through two-stage sintering. The WC alloy comprises the following components in parts by weight: 85-95 parts of WC, 12-25 parts of a binding phase and 0.5-1.4 parts of a grain growth inhibitor, the nanophase accounts for 35-50% of the volume of the binding phase and 35-50% of the total volume of the binding phase, and the grain size is 80-125 nm; the average grain size of WC is 0.6-1.0 [mu] m; and the thickness of an interface P enrichment layer is 8-15 nm (the coverage rate is 85-95%). Through interface engineering and controlled crystallization from amorphous to nanocrystalline, the relative magnetic conductivity is 1.001-1.015, the hardness HRA is 90.5-93.0, the strength TRS is 2.2-3.0 GPa, the toughness KWP is 300-450 N / mm, and the magnetic saturation strength is 0.02-0.15 T. The problem of decoupling of the magnetic property and the mechanical property of a traditional non-magnetic hard alloy is solved, and the non-magnetic hard alloy is suitable for magnetic sensitive environments such as semiconductor equipment, precise measurement, MRI tools and oil service logging.

The invention belongs to the technical field of high-frequency planar transformers, and relates to a butterfly-shaped planar transformer with a twisted primary side and an anti-coupling secondary side and a switching power supply. The winding comprises a primary winding and a secondary winding; the magnetic core is of a four-core-column butterfly-shaped structure, and the secondary winding and the primary winding respectively surround two core columns in the center of the magnetic core; the winding directions of the secondary winding current around the two middle columns of the magnetic core are the same; the primary winding is positively coupled with one secondary winding and reversely coupled with the other secondary winding; according to the two-core-column matrix type transformer, the problem that magnetic saturation is caused by the magnetic flux of direct-current magnetic bias at the connecting part of the transformer is solved, so that the two-core-column matrix type transformer can be applied to a switching power supply with direct-current magnetic bias and a power electronic converter; compared with a traditional scheme, the efficiency and the power density of the transformer are remarkably improved.

The invention belongs to the field of integrally-formed inductor preparation, and provides iron-based alloy powder, a preparation method of a transfer plastic package integrally-formed inductor and the inductor. In order to solve the problem of a formula of atomized powder with high magnetic conductivity and high bias, the iron-based alloy powder is provided and comprises the following components in percentage by weight: 75 to 92 percent of Fe, 5 to 10 percent of Ni, 3.0 to 5.0 percent of Si, 0.5 to 2 percent of B, 1 to 2 percent of P, 0.1 to 0.5 percent of Co, 0.5 to 1 percent of C, 0.5 to 3 percent of Cr and 0.1 to 1 percent of Mn. And the magnetic conductivity and the saturation characteristic of the alloy iron-silicon-chromium powder can be improved.

The present invention belongs to the field of fast mechanical switch operating mechanism, and discloses an electromagnetic repulsion mechanism coil based on a slotted yoke, comprising: a coil frame, a baffle, a fastener, a winding coil and a yoke; the yoke is a radially slotted separate structure, a coil frame is arranged at the center of the yoke, the outside of the yoke is surrounded by fasteners and fixed together on the baffle, and a winding coil is arranged inside the yoke; the flow path of the induced eddy current in the yoke is increased by radial grooving, and the eddy currents in the yokes on both sides of the slots are in opposite directions, which offsets the demagnetization effect of the eddy current, reduces spatial magnetic leakage, improves energy conversion efficiency, and improves driving efficiency. The electromagnetic repulsion mechanism coil provided by the present invention can effectively reduce the eddy current loss and magnetic saturation effect of the yoke itself, help reduce spatial magnetic leakage, and improve the driving efficiency of the electromagnetic repulsion mechanism.

The invention provides an iron-silicon-aluminum magnetic powder core and a preparation method and application thereof. The Fe-Si-Al magnetic powder core comprises a Fe-Si-Al magnetic powder base body and a coating layer coating the surface of Fe-Si-Al magnetic powder. And the coating layer comprises silicon dioxide and aluminum phosphate. According to the Fe-Si-Al magnetic powder core provided by the invention, the silicon dioxide and the aluminum phosphate are used as the mixed insulating coating layer, so that the resistivity of the Fe-Si-Al magnetic powder core is increased, the eddy-current loss among particles is effectively reduced, meanwhile, the maximum forming density of the material is ensured, and a relatively high saturation magnetic flux density Bs is obtained, so that a high direct-current superposition characteristic is obtained; and the aim of giving consideration to low loss and high direct current superposition characteristics is fulfilled.

The invention discloses a method for preparing (SmxY1-x) Co5 rare earth magnetic particles with high magnetic properties by a chemical method, and belongs to the field of rare earth magnetic materials. The invention particularly relates to a novel technology for preparing (SmxY1-x) Co5 ternary alloy magnetic powder with high magnetic properties by combining chemical liquid phase synthesis with calcium reduction reaction. A Sm (OH) 3 / Y (OH) 3 / Co (OH) 2 (at) Ca (OH) 2 crystalline state mixed precursor prepared by chemical coprecipitation and a hydrothermal reaction is uniformly subjected to a complete calcium reduction reaction with a certain amount of metal calcium particles, KCl and CaCl2 diffusion media in an argon atmosphere, and the magnetic powder is prepared. The saturation magnetization intensity and the residual magnetization intensity of the magnetic powder are improved by doping the yttrium element, but the coercive force of the magnetic powder is slightly reduced, and the method provides a new thought for preparing high-performance rare earth magnetic particles.

The invention provides NiCuZn ferrite with high magnetic conductivity and a preparation method thereof. The preparation method comprises the following steps: (1) carrying out primary ball milling on raw materials of the NiCuZn ferrite, and pre-sintering to obtain a pre-sintered material; and (2) the pre-sintered material and a doping agent are subjected to secondary ball milling, and after granulation, molding and sintering, the NiCuZn ferrite is obtained, and the doping agent comprises WO3 and TiO2. Through combined doping of WO3 and TiO2, the sample density can be improved, the magnetic conductivity, the Curie temperature and the saturation flux density can be improved, meanwhile, the magnetic loss is reduced, and the final ferrite can be suitable for electronic elements with high requirements for the magnetic conductivity.

The invention belongs to the technical field of low-voltage power distribution, and particularly relates to a control method and system for low inductive reactance and low transient impulse voltage, the magnetic flux density and the change rate of a magnetic core are collected in real time through a sensor, a dynamic threshold value is calculated based on the magnetic flux density, and the critical point of the magnetic core entering a nonlinear magnetization area is accurately identified. And comparing the magnetic flux density monitored in real time with a dynamic threshold value, generating a deviation signal and judging the state of the magnetic core. Once it is confirmed that the magnetic core is in a non-linear magnetization state, an adjustment mechanism is triggered immediately, winding current distribution is adjusted to change the magnetic flux path length of the magnetic core, and periodic pulse signals are applied to prevent depth saturation of the magnetic core. In addition, by monitoring the adjusted magnetic core magnetic flux density recovery rate, demagnetization processing parameters and pulse signal strategies are optimized, and continuous and efficient operation of the system is ensured. According to the method, the transient voltage suppression capability and stability of the system are remarkably improved, and the overall performance and reliability are enhanced.

The present invention discloses a nanocrystalline current transformer with DC component resistance and a method for using the same, comprising: a current transformer having a magnetic core hole extending from front to back in the middle of the front side of the current transformer. The device is provided with a secondary-side disconnection detection and protection mechanism, which effectively prevents the internal magnetic field imbalance of the transformer caused by the disconnection of the secondary circuit, avoids the core magnetic flux saturation and the generation of potential high electromotive force, thereby protecting the transformer itself and peripheral equipment, and reducing the risk of power system failures such as fire or short circuit. At the same time, a live conductor centering fixing mechanism is provided to ensure the stable centering position of the conductor in the transformer core hole, optimize the magnetic field distribution, reduce magnetic leakage, significantly improve the accuracy and stability of current measurement, and reduce measurement fluctuations introduced by conductor shaking, providing more accurate data support for harmonic analysis, fault detection, and power quality monitoring of the power system.

The application relates to a method for one-step synthesis of strong magnetic hydrophobic Fe3O4 nanoparticles at low temperature and the Fe3O4 nanoparticles and application, and belongs to the technical field of nano material preparation. The method comprises the following steps: adding a ferrous sulfate solution into a mixed solution of sodium hydroxide and sodium nitrate, heating and stirring to react, adding oleic acid in the reaction process, and obtaining black Fe3O4 crystals after the reaction is completed. The saturation magnetization of the obtained strong magnetic hydrophobic Fe3O4 nanoparticles can reach 85.69 emu / g at most, and the water contact angle can reach 148.95 DEG. The one-step synthesis reaction only needs to use oleic acid as a regulator, avoids an extreme high-temperature and high-pressure environment, does not need to use a toxic chemical solvent, the condition is mild, the process is simple, the operation condition is easy to control, and the method has a wide application prospect.

A raw material alloy for a magnetic refrigeration material according to the present invention is expressed by compositional formula R1(M1 1-xA1 x)y. The magnetic refrigeration material of the present invention contains as a main phase a La(Fe,Si)13 compound that is expressed by the compositional formula R1(M1 1-xA1 x)y and has a NaZn13 crystal structure, and further contains a sub-phase containing a rare earth element (R2). The percentage of the sub-phase containing the rare earth element (R2) in the raw material alloy for the magnetic refrigeration material is 0.1 vol% or more, and the percentage of alpha-Fe is 0.5 vol% or less when alpha-Fe is not included or when alpha-Fe is included. The present invention makes it possible to provide a raw material alloy for a magnetic refrigeration material in which the amount of change in the transition temperature due to the homogenization temperature is small, and in which hydrogen is absorbed to a saturation amount of hydrogen and the transition temperature is stable under a wide range of hydrogenation conditions.

The invention discloses a ferromagnetic material internal defect leakage magnetic field increasing method based on alternating current and direct current composite magnetization, which comprises the following steps of: fixing a workpiece at the center of a composite exciting coil, and synchronously applying direct current and high-frequency alternating current; after pure direct current magnetization is saturated, current is locked, and a basic leakage magnetic field is established; the surface magnetic conductivity is dynamically reduced by overlapping alternating current, and the magnetic shielding effect is weakened; a leakage magnetic field signal is scanned and collected through a differential Hall sensor array, and background magnetic field deduction, peak value comparison and adaptive filtering processing are carried out; and determining an optimal magnetization parameter combination by adopting a gradient descent method and Bayesian optimization. The system is integrated with a composite excitation coil and a signal conditioning unit, so that synchronous excitation, signal acquisition and real-time analysis are realized. The leakage magnetic field signal at the deep defect is enhanced through alternating-current and direct-current composite magnetization, the problem of signal weakening caused by traditional direct-current saturation is solved, the defect detection sensitivity and efficiency are improved, and the method is suitable for non-destructive detection scenes of ferromagnetic materials.

The invention discloses an ocean deepwater weakly cemented sandstone saturated water nuclear magnetic T2 spectrum correction method, which comprises the following steps: 1, making a standard rock sample, and drying the rock sample until the quality is kept stable; 2, saturating the dried rock sample to a completely saturated state by using a turbid liquid, and carrying out nuclear magnetic T2 spectrum measurement to obtain a nuclear magnetic T2 spectrum of the weakly cemented rock sample under the condition that pores contain tiny solid impurities; 3, after displacing and drying the rock sample in the previous step, carrying out saturated water treatment by utilizing pure water, and then carrying out nuclear magnetic T2 spectrum measurement to obtain a nuclear magnetic T2 spectrum of the rock sample in a state that the pores contain the pure water; 4, constructing the nuclear magnetic T2 spectrums in the two states into a data set, and inputting the data set into a deep neural network model for training; and 5, correcting the nuclear magnetic T2 spectrum under the condition that the pores contain the tiny solid impurities by using the trained deep neural network model. According to the method, the nuclear magnetic T2 spectrum is corrected by using the deep neural network model, and the problem of signal attenuation distortion caused by impurity interference is effectively solved.

The present invention comprises a method for jointly processing data from the nuclear magnetic resonant (NMR) response of oil and rock samples in in natura condition, and its main product is the delimitation of the oil saturation (So) present in the rock samples, i.e., the determination of the range of admissible values of the volumetric fraction of the porous volume of the rock occupied by such fluid. The method requires a small volume of oil, originating from or of a composition similar to the oil present in the rock being tested, since it is based on both the measurement of the NMR response of the rock sample and the response of the fluid sample. These two sets of data feed a statistical inference scheme that (1) determines a range of admissible values for the So of the sample, delimited by the minimum and maximum oil saturation values compatible with the two sets of data presented; (2) produces, for each of these extreme values of admissible So, a decomposition of the rock relaxation time spectrum into two complementary spectra, the first highlighting the signatures relating to oil and the second comprising the distribution of the rock relaxometric signatures that cannot correspond to such fluid under the prescribed saturation condition.

The invention discloses a plastic package magnetic material for a chip inductor, a preparation method of the plastic package magnetic material and the inductor. The plastic package magnetic material comprises 96wt%-99wt% of alloy powder, 1wt%-4wt% of a resin layer and at least two atomic layer deposition layers, the two adjacent layers in the at least two atomic layer deposition layers are made of different materials; the at least two atomic layer deposition layers are coated on the outer surface of the alloy powder, and the resin layer is coated on the outer surfaces of the at least two atomic layer deposition layers. The plastic package magnetic material provided by the invention has relatively high magnetic conductivity, high saturation and low loss in a low-frequency band while having good fluidity, insulation and voltage resistance, so that miniaturization, lightness, thinness and high performance of an inductor are realized.