494results about "Shielding materials" patented technology

The invention discloses a non-contact magnetoelectric composite current sensor with magnetism gathering and magnetic shielding. A sensor core is composed of a magnetoelectric sensing element, a magnetofluid layer, a magnetism gathering structure and a magnetic shielding layer. The magnetoelectric sensing element is made of manganese-doped lead magnesium niobate and amorphous alloy film composite materials, the outer side of the sensing element is coated with a magnetofluid layer made of soft magnetic composite materials, the magnetism gathering structure is made of permalloy materials with high magnetic conductivity and is divided into an upper part and a lower part, the upper part accommodates the sensing element and the magnetofluid layer, and the lower part accommodates the magnetic gathering structure. And the lower part is provided with a standardized groove for placing a conductor to be tested. The outermost layer is a magnetic shielding layer composed of multiple layers of nanocrystalline alloy strips, the vertical split type design is also adopted, and it is ensured that the magnetic shielding layer is tightly matched with the magnetic gathering structure through precision machining. The upper magnetic shielding layer and the lower magnetic shielding layer are detachably connected, and field installation is facilitated. The overall structure is compact, a circuit does not need to be disconnected during installation, and the device is especially suitable for on-line current monitoring requirements in the fields of smart grids, industrial automation and the like.

The invention provides a flexible interference network deployment method and system based on carbon fiber conductive cloth. The method comprises the following steps: acquiring space field intensity data in a non-uniform electromagnetic field environment, and performing physical field correction on the space field intensity data to generate compensation field intensity data; a metal screen cloth structure is formed on the surface of the carbon fiber, and porosity distribution parameters are obtained through gradient difference generation treatment; forming a metal mesh cloth layer with gradient pore size distribution, and performing deformation adaptation on the pore size distribution in combination with real-time bending curvature data to generate dynamic and stable porosity distribution; based on electromagnetic field intensity associated region division on the metal mesh layer, dynamically adjusting the grounding resistance value of each divided region, and generating a resistance regulation and control parameter; physical connection between the metal screen cloth layer and the grounding end is realized, and electromagnetic shielding effectiveness parameters are output. According to the invention, adaptive shielding effectiveness optimization of the flexible interference network in a complex electromagnetic environment is realized.

The invention provides an iron-based magnetically soft alloy strip and a preparation method and application thereof, the alloy composition of the iron-based magnetically soft alloy strip is FeaCobCrcSidBeWfAlgGehRei (MxNy) j, 75 < = a < = 81, 5 < = b < = 11.9, 5 < = c < = 10, 2 < = d < = 4, 2 < = e < = 4, 2 < = f < = 4, 1 < = g < = 3, 0.5 < = h < = 2, 0.5 < = i < = 1.5, 0.1 < = j < = 1, x: y = 1, and a + b + c + d + e + f + g + h + i + j = 100; m is Ti and / or Zr, and N is nitrogen; wherein the nitride material has an iron-based grain phase and a germanium-tungsten-containing precipitated phase, the nitride is distributed between the interfaces of the iron-based grain phase, and the average grain size of the iron-based grain phase is 5-20 nm. The iron-based magnetically soft alloy strip can be suitable for complex application scenes, and the magnetic performance and reliability of the iron-based magnetically soft alloy are improved.

The embodiment of the invention discloses electronic equipment, a composite board and a preparation method thereof, and relates to the field of board structures. The conductive performance of the composite board is improved. According to the specific scheme, the composite board comprises a composite layer, a carbon fiber yarn layer, a conductive layer and a floor. The composite layer is provided with a groove structure; the carbon fiber yarn layer is embedded in the composite layer, and part of the carbon fiber yarn layer is located in the groove structure. The conductive layer and the composite layer are stacked, and the conductive layer covers at least part of the groove structure and is electrically connected with the carbon fiber yarn layer. One side of the conductive layer away from the composite layer is electrically connected with the floor. And the conductive layer is electrically conducted with the carbon fiber yarn layer. And the carbon fiber yarn layer embedded in the composite layer is electrically connected with the floor through the arrangement of the groove structure and the conductive layer. Therefore, charges in the whole carbon fiber yarn layer can flow to the floor through the conductive layer. And the whole carbon fiber yarn layer has an electromagnetic compatibility protection effect. When the composite board is applied to the electronic equipment, the electromagnetic compatibility protection performance of the electronic equipment can be improved.

The present invention provides a high-temperature nylon / nylon 66 alloy electromagnetic shielding composite material and a preparation method therefor. The raw materials of the composite material comprise: high-temperature nylon, nylon 66, modified glass fibers, modified carbon nanotubes, expanded graphite and an auxiliary agent. The high-temperature nylon and the nylon 66 serve as a matrix resin; the modified glass fibers, the modified carbon nanotubes and the expanded graphite are compounded to serve as a filling agent, so as to enhance the mechanical strength of the matrix resin; and the compatibility between the matrix resin and the filling agent is enhanced by means of the auxiliary agent. The dissipation path of electromagnetic waves is further increased by means of the modified carbon nanotubes, thereby enhancing the interfacial polarization effect; the dispersing capacity of the modified carbon nanotubes in the matrix resin is enhanced by means of the expanded graphite, thereby reducing the surface contact resistance; and the electrically conductive paths and the heat dissipation are increased by means of the modified glass fibers, so as to further improve the electromagnetic wave loss capacity. The high-temperature nylon / nylon 66 alloy electromagnetic shielding composite material prepared in the present application not only has excellent dielectric properties, but also has good heat-conducting properties.

An electromagnetic wave- and magnetic field-absorbing-and-shielding sheet according to an exemplary embodiment of the present invention is implemented by comprising: an electromagnetic wave- and magnetic field-absorbing-and-shielding unit having a plurality of magnetic layers stacked to shield electromagnetic waves and magnetic fields; and an electromagnetic wave-absorbing adhesive member, which is arranged between the adjacent magnetic layers to absorb electromagnetic waves that have transmitted the magnetic layers or are reflected from the magnetic layers, and fixes the adjacent magnetic layers. Accordingly, together with an electromagnetic wave- and magnetic field-shielding function, the present invention has a function of enabling most of the electromagnetic waves reflected during shielding to be absorbed to minimize influence on surrounding electronic components, electronic devices, or a user of the electronic devices, caused by electromagnetic waves reflected during shielding and the magnetic field shielding, and thus can be widely applied to various electronic devices and the like.

The invention discloses a zero magnetic shielding device and a use method thereof, and the device comprises a magnetic shielding cylinder which is composed of a shielding cylinder body and a shielding cover detachably connected with the shielding cylinder body. And the non-magnetic multifunctional test frame is arranged in the magnetic shielding cylinder and consists of an arc-shaped seat, a lifting mechanism, a test bedplate, a track, a storage rack, a Helmholtz coil and a folding nylon magnetic sensing assembly. When the magnetic flux and residual magnetism switching test is carried out on the object to be tested in the magnetic shielding cylinder, the non-magnetic multifunctional test frame does not need to be replaced, the efficiency of the magnetic flux and residual magnetism switching test on the object to be tested in the magnetic shielding cylinder is improved, and the advantage of convenient switching test is achieved. And the method has the advantages of high measurement precision and wide application range.

The invention relates to a composite nanofiber membrane and a preparation method and application thereof, and belongs to the technical field of wearable electromagnetic shielding materials. The preparation method comprises the following steps: dissolving polyacrylonitrile in a solvent, and spinning to obtain a polyacrylonitrile nanofiber membrane; then, the polyacrylonitrile nanofiber membrane is soaked in a trihydroxymethyl aminomethane hydrochloride solution containing dopamine; soaking the dopamine-coated fiber membrane in a mixed solution containing a copper salt or a silver salt, and then soaking the dopamine-coated fiber membrane in a reaction solution to obtain a modified nanofiber membrane; then spraying a dispersion liquid containing a conductive filler onto the modified nanofiber membrane to obtain a conductive filler modified nanofiber membrane; and finally, dissolving polyurethane into a solvent, and spinning by taking the conductive filler modified nanofiber membrane as a receiver to obtain the composite nanofiber membrane. The composite nanofiber membrane has excellent electromagnetic shielding performance, directional perspiration ability, air permeability, photothermal conversion ability, antibacterial property, mechanical strength and flexibility.

A display device includes a silicon substrate including a display area including a light emitting element, and a pixel circuit portion which is inside the silicon substrate and connected to the light emitting element, and a non-display area which is adjacent to the display area. The non-display area includes a driving circuit portion which is inside the silicon substrate and through which an electrical signal is provided to the display area, and an electrostatic shielding layer covering the driving circuit portion.

A battery pack with electromagnetic compatibility (EMC) for an electric vehicle is presented that includes a battery pack housing, at least one battery module enclosed within the battery pack housing, and an electronics assembly enclosed within the battery pack housing, in which the electronics assembly comprises a DC-DC converter and an electronics assembly casing, wherein at least one of the electronics assembly and battery pack housing includes an electromagnetic interference (EMI) shield to enable EMC. The electronics assembly includes a battery management system (BMS) circuit board and a DC-DC converter control circuit board and a DC-DC converter power electronics board. The electronics assembly is of substantially a same dimension of a battery module, in which the EMI shield comprises at least one of a metallic screen, metallic wires, a metallic tape, a metallic sheet, a metallic coating, paramagnetic materials, carbon based materials and metallic and / or carbon particle-infused composites.

The invention discloses a self-calibration strain test system and method for a propeller composite material, and solves the problems of high-precision measurement and real-time calibration of dynamic strain in a complex flow field environment. The core of the system comprises a linear fiber grating sensor array attached to the surface of a blade and an optical fiber demodulator integrated on a propeller hub, sensors are symmetrically arranged in the spanwise direction, and infrared transmitting / receiving devices in pairs intersect at the circle center O of the propeller hub when positioning is accurate, so that a global reference is formed; a single sensor is installed through a double-shaft flexible hinge, a shape memory alloy (SMA) wire driving mechanism is integrated, and spanwise / chordwise independent micro-motion calibration can be achieved according to infrared intersection point offset. A failure alarm is arranged in the sensor, gallium-indium-tin alloy is filled in hollow glass beads, alarm is triggered only when more than or equal to 3 beads are broken to form a conductive path, false alarm is avoided, and the problem of dynamic strain monitoring of the large-deformation composite propeller in high-pressure, low-temperature and strong-electromagnetic-interference environments is solved through the anti-electromagnetic-interference module.

The present invention belongs to the technical field of microwave-absorbing materials, and specifically relates to a method for preparing a cobalt / attapulgite / carbon nanocomposite fiber with microwave-absorbing properties. The preparation method comprises the following steps: mixing a magnetic metal salt, a polymer, a solvent, and nano-attapulgite in a specific proportion, reacting under heating conditions and at room temperature to obtain a mixed spinning solution; electrospinning the mixed spinning solution to obtain composite nanofibers; and carbonizing the obtained composite nanofibers to obtain a cobalt / attapulgite / carbon nanocomposite fiber with microwave-absorbing properties. The present invention has the beneficial effect that, due to the adoption of the above-mentioned technical solution, the carbon nanocomposite fiber of the present invention combines excellent properties such as light weight, strong absorption, a wide effective absorption bandwidth, and a low filling ratio. The carbon nanofibers have excellent dielectric properties, electrical conductivity, thermal stability, and low density. Carbon nanofibers are expected to be used to produce ideal microwave-absorbing materials.

Provided is a cured or uncured electromagnetic wave shielding sheet with a carbon nanotube unwoven cloth having a thickness of not larger than 1 mm being impregnated with a resin and / or with the resin being laminated thereon, the sheet exhibiting a superior electromagnetic wave shielding performance with respect to millimeter waves and terahertz waves. The sheet may for example be one with a carbon nanotube unwoven cloth having a thickness of not larger than 1 mm and a specific resistance of not larger than 0.005 Ω·cm being impregnated with a resin and / or with the resin being laminated thereon; or one with a carbon nanotube unwoven cloth having a thickness of not larger than 1 mm, an air permeability of not larger than 0.5 cm3 / cm2·s and a specific resistance of not larger than 0.005 Ω·cm being impregnated with a resin.

An electromagnetic shielding and heat-conducting multi-layer material and a preparation method thereof. The multi-layer material includes an electric field shielding layer, an epoxy heat-conducting adhesive layer, and a magnetic field shielding layer. The electric field shielding layer includes a copper foil layer with a thickness of 5-12 μm. The magnetic field shielding layer has a thickness of 1-3 mm and includes a resin matrix A and carbon fiber cloth. By weight, the resin matrix A includes: 100 parts of bismaleimide resin, 60-68 parts of 3,3-diallylbisphenol A, 32-40 parts of triallyl isocyanurate, 18-20 parts of N,N-dimethylformamide, 100-160 parts of magnetic field shielding filler, 8-10 parts of di-sec-octyl phthalate, and 0.3-0.8 parts of cobalt naphthenate. The magnetic field shielding filler is compounded by nano-manganese zinc ferrite and micron nickel powder in a mass ratio of (80-120):(30-40). The electromagnetic shielding and heat-conducting multi-layer material of the present invention has both electric field and magnetic field shielding functions and is particularly suitable for high magnetic field and high electric field application environments.

The embodiment of the invention provides a novel high-integration ultra-wideband dual-channel high-energy microwave module for countering an unmanned aerial vehicle system, and relates to the field of electronic countermeasure, the module comprises a module cavity, the module cavity is internally provided with a high-voltage-resistant radio frequency substrate and a high-energy-storage radio frequency power supply control daughter board, and the high-voltage-resistant radio frequency substrate and the high-energy-storage radio frequency power supply control daughter board are arranged in the module cavity; a high-power radio frequency chip, an ultrahigh-power radio frequency chip and a high-voltage isolator are welded on the high-voltage-resistant radio frequency substrate; the high-power radio frequency chip and the ultrahigh-power radio frequency chip are connected with the high-energy-storage radio frequency power supply control daughter board; the high-power radio frequency chip and the ultra-high-power radio frequency chip are arranged in a cascade form; and the high-voltage isolator is located at the output cascade end of the last-stage ultra-high power radio frequency chip in the cascade chip structure. According to the invention, ultra-wideband high-power radio-frequency signal and high-airtightness transmission can be realized, single-channel output power of tens of thousands of watts can be provided, and the ultra-wideband high-power radio-frequency power divider is suitable for application scenes such as portable unmanned aerial vehicle countering or high-maneuverability unmanned aerial vehicle countering.

The invention provides a preparation method of a CoFe alloy fiber microwave absorbent, which comprises the following steps: immersing cotton fibers in an aqueous solution containing ferric salt and cobalt salt for dipping, taking out, and drying to obtain cotton fibers loaded with iron ions and cobalt ions; under the nitrogen atmosphere, the temperature is increased to 600-800 DEG C from the room temperature at the speed of 4 DEG C / min, after constant-temperature roasting, natural cooling is conducted to the room temperature, and the CoFe alloy fiber microwave absorbent is obtained. The invention further provides application of the CoFe alloy fiber microwave absorbent, and the CoFe alloy fiber microwave absorbent is used for preparing stealth materials or / and electromagnetic protection materials. The raw materials are wide in source and low in cost, only an impregnation method and a roasting method are adopted, no organic solvent is used, and the method is green and environmentally friendly; the technological process is simple, easy to operate, low in synthesis cost and suitable for industrial production; the prepared CoFe alloy fiber microwave absorbent is high in magnetism, facilitates double-layer optimization design of microwave absorption performance, and has the advantages of being good in microwave absorption performance and light in weight.

The invention belongs to the technical field of hydrophobic electromagnetic shielding materials, and particularly relates to an asymmetric electromagnetic shielding composite film and a preparation method and application thereof. The PNTs are polypyrrole nanotubes, after Na2MoO4. 2H2O and CH4N2S are added and subjected to a high-temperature reaction, a MoS2 flower-shaped shell structure can grow on the PNTs, the layered structure and the high specific surface area of MoS2 contribute to enhancing scattering and absorption of electromagnetic waves, and rich defect sites can induce dielectric polarization to achieve dielectric loss. Introducing the PNTs (at) MoS2 core-shell nanowire as an electromagnetic wave absorbent into a polylactic acid / dichloromethane system, then putting the system into a culture container in which a conductive filler is pre-paved, and standing and volatilizing at room temperature by adopting an ethanol solution as a volatile agent to finally obtain a three-layer asymmetric electromagnetic shielding composite film comprising the conductive filler, the PNTs (at) MoS2 structure and a polylactic acid matrix from bottom to top. And an asymmetric conductive gradient network is constructed, and the EMI shielding performance which mainly focuses on absorption is remarkably improved, so that the secondary radiation problem of electromagnetic waves is reduced.

Provided is a sheet-shaped magnetic member. The sheet-shaped magnetic member comprises magnetic ribbons with anisotropy, and includes a first group, a second group, and a third group. The third group is arranged so that a direction of anisotropy of the magnetic ribbons is along a direction different from both a direction of anisotropy of the first group and a direction of anisotropy of the second group. The first group, the second group, and the third group are arranged next to each other.

Composite materials for simultaneous thermal management and electromagnetic interference screening of radiofrequency-based electronic systems are provided. The materials contain a phase change material and one or more electrically and thermally conductive filler particles. The materials provide a passive system for thermal management and EMI shielding that is lightweight, does not contain moving parts, and does not require an external power supply.

An electromagnetic pulse (EMP) protection control method and system for an electronic device, and a terminal device, relating to the technical field of EMP protection. The method comprises: acquiring EMP data of a target electronic device in real time; processing and analyzing the EMP data to obtain a signal strength and a signal frequency which correspond to the EMP data; on the basis of comparative analysis between the signal strength and a corresponding specific threshold, between the signal frequency and a corresponding specific threshold, and between the EMP data and a known EMP event database, determining whether an EMP event occurs; and if the EMP event occurs, using a protection strategy to perform a protection operation on the target electronic device. The EMP protection control method for an electronic device is applied to the electronic device, so that the protection strategy is used to protect the electronic device when the EMP event occurs to the electronic device, so as to enable the electronic device to continue working under a redundant system, thereby improving the running reliability of the electronic device, and also ensuring that the electronic device can continue working when the EMP event occurs.

The invention discloses a stealth plate, an integrated plate containing the stealth plate and a forming process method of the stealth plate. The forming process method comprises the following steps that a resistive film is coated with an adhesive in a scraping mode, the resistive film coated with the adhesive is laid on PMI foam, and a single-layer wave absorbing plate is obtained after curing forming; performing performance detection on the single-layer wave-absorbing plate, numbering the single-layer wave-absorbing plate, and performing laser engraving on the numbered single-layer wave-absorbing plate; preparing a plurality of single-layer wave-absorbing plates, stacking the plurality of single-layer wave-absorbing plates up and down, bonding and curing to obtain a multi-layer wave-absorbing plate; cutting and punching the obtained multi-layer wave absorbing plate; the inner skin and the outer skin are fixed to the inner side and the outer side of the multi-layer wave absorbing plate respectively; and excision, modification and inspection are carried out. The prepared invisible plate can be directly arranged on the outer side of a cabin body, not only can have the wave absorbing performance, but also can be used as a structural layer, and the overall structural performance is improved; by changing the structure of the cabin plate, the exposed layer outside the cabin can meet the performance requirement to reduce the expensive wave-absorbing coating cost.

Provided is an electromagnetic wave shielding material having a good shielding property in a low frequency range. The electromagnetic wave shielding material has a structure in which at least one ferromagnetic layer and at least one non-magnetic conductive metal layer is laminated together, wherein the electromagnetic wave shielding material further includes a treated film containing an alloy including copper and nickel on at least one surface of the non-magnetic conductive metal layer.

Provided is a magnetic field shielding module for an electric vehicle. The magnetic field shielding module for an electric vehicle according to an embodiment of the present invention is utilized in a wireless power transmission module for an electric vehicle, and comprises: a shielding layer including a plurality of unit blocks which are made of ferrite materials so as to be able to block a magnetic field generated from a flat coil in which a conductive member is wound multiple times; and a coil accommodation groove recessed to a certain depth from one surface of the shielding layer so as to be able to accommodate the thickness of the flat coil. The shielding layer is formed in a plate shape having a certain area by arranging the plurality of unit blocks adjacent to each other.

The invention belongs to the technical field of wave-absorbing composite materials, and particularly relates to a low-frequency-band high-permeability wave-absorbing film material and a preparation method thereof. The wave-absorbing film material provided by the invention is prepared from the following raw materials in parts by weight: 25 to 60 parts of conjugated structure modified polyimide, 25 to 40 parts of magnetic absorbent, 5 to 15 parts of carbon hollow fiber and 0 to 10 parts of functional additive. The wave-absorbing film material provided by the invention has relatively good wave-absorbing performance and mechanical performance in a low-frequency wave band, and has a relatively good application prospect.

The application belongs to the technical field of microwave absorbing materials, and relates to Fe3O4@C magnetic modification MXene-based aerogel microwave absorbing material and a preparation method thereof. The microwave absorbing material has a porous structure, and the inner wall is attached with magnetic double-layer structure Fe3O4@C particles. The outer shell is spindle-shaped amorphous carbon, and the inner core is Fe3O4 magnetic particles. The preparation method comprises the following steps: preparation of nano spindle-shaped Fe2O3 precursor, preparation of magnetic double-layer structure Fe3O4@C particles, preparation of single-layer MXene nanosheet, and preparation of Fe3O4@C magnetic modification MXene-based aerogel. The Fe2O3 precursor is generated by using a hydrothermal method. The Fe2O3 precursor can not only be used as a template of a polydopamine shell, but also can be partially reduced to generate magnetic Fe3O4, so that the wave absorbing performance is enhanced. The polydopamine shell is carbonized at high temperature, and the internal Fe2O3 precursor is reduced to Fe3O4. The magnetic particles are positively charged and naturally adsorbed with the single-layer MXene nanosheet by using polydiallyldimethylammonium chloride treatment. Gelatin is used as a cementing agent in the application, so that the strength of the aerogel is ensured while the economy is ensured.

An apparatus and method for thermal management of electronic devices are disclosed. A magnetic heatsink includes a thermally conductive base with vertical fins and one or more shielded magnet units having an exposed attachment face. A subset of fins form fan-receiving groups with inwardly curved extensions and a bottom slot bent upward to create a protruding lip, cooperating to provide lateral guidance and three-way mechanical locking of a micro fan module that also magnetically couples to the heatsink. A Smart Power Stage (SPS) board carries embedded magnet units and a board-to-board interface to magnetically and electrically engage a designated motherboard zone having a metal pad and connector, enabling tool-less installation, self-alignment and efficient heat transfer. Methods of configuring, servicing, and replacing the fan and SPS board are also described.

In various embodiments, the present application provides electrically conductive metal-plated fibers and continuous processes of preparing metal-plated fibers. Additionally, provided are polymeric articles comprising the provided metal-plated fibers or other fibers prepared by the provided process, said articles having electromagnetic interference shielding effectiveness.

An induction heating type cooktop includes: a case, a cover plate that is coupled to an upper end of the case and that includes an upper plate arranged to receive a target object, a working coil that is disposed in the case and that is configured to heat the target object, a thermal insulation material disposed on the working coil, and a heating thin film coating that is disposed on a surface of the upper plate of the cover plate or a surface of the thermal insulation material and that has a stacked structure in which an adhesive layer and a heating layer are consecutively stacked.

The invention relates to the field of structural wave absorption, in particular to an electromagnetic wave-absorbing material and a preparation method thereof. The electromagnetic wave-absorbing material comprises: a) a honeycomb substrate having a plurality of honeycomb holes penetrating along the thickness direction; the honeycomb holes are filled with the wave-absorbing medium; wherein the wave-absorbing medium is a condensate formed by cooling after paraffin and an absorbent are uniformly dispersed in a molten state; the absorbent has magnetic loss and / or dielectric loss properties. Impedance is adjusted through paraffin, loss is provided through the absorbent, a propagation path is prolonged through the honeycomb structure, and the electromagnetic wave-absorbing material which is reduced in interface reflection, improved in absorption efficiency, good in structural stability and adjustable in absorption performance is achieved.