87results about How to "Good electromagnetic shielding effect" patented technology

An electromagnetic shielding cloth is characterized by comprising nano electromagnetic shielding particles (1), a thermoplastic polyurethane slurry shield layer (2), a fabric (3) and a thermoplastic polyurethane slurry layer surface (4). The thermoplastic polyurethane slurry shield layer (2) comprises nano electromagnetic shielding particles (1); the thermoplastic polyurethane slurry shield layer (2) coats on the surface of the fabric (3); and the thermoplastic polyurethane slurry shield layer (2) is coated with the thermoplastic polyurethane slurry layer surface (4). The electromagnetic shielding polyurethane film woven fabric of the invention has the advantages of excellent electromagnetic shielding effect, water resistance, good flexibility, and long life.

The invention discloses a package structure and package method of an integrated tunable antenna array and a radio frequency module. The package structure comprises a rigid-flexible board and a radio frequency module package body, wherein the rigid-flexible board is used for arranging an antenna array patch, the radio frequency module package body is used for packaging a radio frequency chip, the rigid-flexible board and the radio frequency module package body are vertically and oppositely arranged and are fastened by four bolts and nuts, the four bolts and nuts are arranged at corners and arematched, and the rigid-flexible board is fixedly connected with one side of the radio frequency module package body by a second flexible substrate. With the package structure of the integrated tunableantenna array and the radio frequency module, fabricated by the invention, the integration of the integrated tunable antenna array and the radio frequency module is achieved, moreover, the tuning ofthe antenna array also can be achieved, the package structure has the characteristics of high integration, good electromagnetic shielding effect, antenna gain, high radiation efficiency, small radiation power and low loss, and the demands of different application occasions can be satisfied.

The invention discloses an electromagnetic shielding polymeric material which comprises the following raw materials in portions by weight: 100 portions of polyphenyl thioether, 60-150 portions of polyamide electromagnetic shielding master batch, 20-120 portions of electromagnetic shielding accessory ingredient, 0.2-0.6 portion of antioxidant, 0.4-2 portions of coupling agent and 0.5-3 portions of processing accessory ingredient. The electromagnetic shielding polymeric material of the invention has the advantages of favorable electromagnetic shielding effect, high mechanical strength, good toughness, temperature resistance and easy injection molding.

The invention provides a three-dimensional integration method for a tile TR component subarray element and aims at providing a three-dimensional integration method for a subarray element which is thinin body and light in weight and is capable of effectively improving the assembly efficiency and quality. The three-dimensional integration method is implemented through the following technical schemeof producing a tool base consistent with a radio-frequency T/R printed board in shape and a tool pressing plate, producing opposite and symmetric electroplated metallization steps on the upper and lower surfaces of the radio-frequency T/R printed board and a radiation surface printed board, making the radio-frequency T/R printed board vertically aligned at the radiation surface printed board andshielding and sealing the peripheries of work cavities of T-type MMIC chips; and burying fuzz buttons into circular holes in the radiation surface printed board and then fastening the radio-frequencyT/R printed board and the radiation surface printed board between the steps of the tool pressing plate and a TR low-frequency and wave-controlled circuit board and vertically interconnecting and fastening the radiation surface printed board and the radio-frequency T/R printed board together to achieve interconnection of radio-frequency inner and outer conductors and inner and outer conductors of an antenna board. Radio-frequency assembly of the subarray element of a chip phased-array antenna is achieved through integral integration.

The invention discloses an electromagnetic shielding device for a signal line control circuit protector with a power surge protector. The electromagnetic shielding device is characterized in that an inner shielding body with 1-5 layers and an outer shielding body are of a closed edge-free box structure; a power surge protector (SPD) is arranged between the inner shielding body and the outer shielding body made of low-carbon steel plates with the manufacturing thickness of 10mm; by virtue of the signal line control circuit protector (SPD), current inducted by a high-intensity magnetic field is prevented from entering the shielding bodies along a power supply and signal cable; the power surge protector (SPD) connected with a grounding conductor of the shielding bodies is in grounding or equipotential connection, high current which is instantaneously inducted on the surface of the shielding bodies in the high-intensity magnetic field is discharged, a non-conductive and non-magnetic fixing framework is used for fixing the inner and outer shielding bodies, wire inlet and outlet holes are in a corresponding relationship and are not on the same line, and outward push-and-pull doors are arranged on the side surfaces of the shielding bodies. The electromagnetic shielding device is novel in design, ingenious in combination and easy to mount, and the shielding requirements on the high/low frequency magnetic field are met.

The invention discloses a preparation method of a black polyimide film with static electricity prevention and shielding functions. The preparation method comprises steps as follows: an additive and polyamide acid are adopted, wherein the additive accounts for 0.5%-5% of polyamide acid in weight; the additive comprises nano-nickel powder, carbon black and a coupling agent, and nano-nickel powder accounts for 1%-8% of the total quantity of the additive; the carbon black accounts for 90%-98% of the total quantity of the additive; the coupling agent accounts for 1%-2% of the total quantity of the additive; polyamide acid is obtained from diamine and dianhydride through polycondensation in a solvent; during synthesizing, the nano-nickel powder, the carbon black and the coupling agent are dissolved in the solvent firstly, then respective required reacting weights of diamine and dianhydride are calculated in an equal molar ratio, polyamide acid is obtained through synthesis, and a product is obtained through defoaming and film casting. The product has the static electricity prevention effect, the volume resistivity of the product is 10<4>omega*cm-10<9>omega*cm, and meanwhile, the product has the excellent electromagnetic shielding effect and can be applied to the electronic fields such as a high-end flexible circuit board and the like.

The invention belongs to the technical field of conductivity and discloses a nylon fiber surface chemical silver plating method which comprises the following steps: (1) removing oil, namely putting afixed amount of a fiber into a clean container, and putting an alkali oil remover for reducing surface tension of the fiber into the container; (2) carrying out sensitization treatment with a sensitization liquid A, namely completely soaking the fiber obtained in the step (1) into the sensitization liquid A prepared on site, and enabling the surface of the fiber to adsorb a layer of a metal with catalysis activity; (3) carrying out sensitization treatment on a sensitization liquid B, namely completely soaking the fiber obtained in the step (2) into the sensitization liquid B prepared on site,and forming hydrogen bonds by carbonyl functional groups on the surface of the fiber and carbonyl functional groups in the sensitization liquid B; (4) carrying out activation, namely completely soaking the fiber obtained in the step (3) into a silver amino solution prepared on site; (5) putting a fixed amount of glucose restore into the solution obtained in the step (4). By adopting the method, asilver plated layer with a solid plated layer can be made, and a conductive fiber with good conductivity can be manufactured.

The invention discloses nickel-plated carbon fiber shielding paper and a preparation method thereof. The preparation method comprises the following process steps: firstly, preparing nickel-plated carbon fibers, preparing a bleached wood pulp, and after the nickel-plated carbon fibers are chopped, adding the chopped nickel-plated carbon fibers into the bleached wood pulp to mix according to a volume fraction of 5-30%; and then, adding a dispersant into the obtained mixture to carry out aqueous phase dispersion, carrying out papermaking on the dispersed mixed pulp, and squeezing and drying the obtained product so as to obtain nickel-plated carbon fiber shielding paper. Through preparing shielding paper by using nickel-plated carbon fibers, the electrical conductivity of the shielding paper is better than that of a common carbon fiber shielding paper, the electromagnetic shielding effect is better, and the shielding effectiveness of the shielding paper in a high-frequency area is similar to that of a conductive fabric, therefore, the shielding paper is suitable for being applied to occasions with stricter requirements on shielding effectiveness. Meanwhile, the strength of the nickel-plated carbon fiber shielding paper disclosed by the invention is higher than that of a common carbon fiber paper, and the comprehensive performance of the shielding paper is more excellent, therefore, the shielding paper accords with the requirements of high-performance materials.

The present invention provides a natural graphite/aluminium composite radiating fin and a preparation method thereof, relating to the field of heat radiation of heating elements of electronic products and the field of electromagnetic shielding of electronic products. The natural graphite/aluminium composite radiating fin includes an aluminum foil layer and graphite layers located on two faces of the aluminum foil layer. The aluminum foil layer includes an aluminium base material and coarsening layers located on two faces of the aluminium base material. Holes are distributed on the surface of the coarsening layer. The coarsening layer connects the graphite layer in an occlusion manner. The preparation method includes the steps as follows: pre-processing the surface of the aluminium foil; performing a coarsening process for the aluminium foil; stacking expanded worm-like graphite evenly and tiling the expanded work-like graphite on the aluminium foil; and performing staged rolling to obtain the natural graphite/ aluminium composite radiating fin. The graphite layer connects the aluminium foil layer in an occlusion manner through holes so that the interface resistance of the aluminium foil and the graphite is lesser and the thermal conductivity in the Z-axis direction is increased greatly, the radiating fin has the excellent thermal conducting property and the excellent electromagnetic shielding effect, the radiating fin has the anti-stretching property, and the radiating fin can be bended for 180 degrees.

The invention provides a CT (current transducer) energy acquisition-based ultrasonic bird repelling device for a series compensation platform, and can effectively prevent and control the problem of bird trouble of a series capacitor compensation device. In the ultrasonic bird repelling device, a circuit energy acquisition CT is adopted to supply power, large current passing through a circuit is converted into a required current, the current passes through an isolated CT realize electrical isolation, the high frequency part of power frequency current is filtered by virtue of a low-pass filter, direct current voltage is rectified and output by virtue of a rectifier, a high-frequency signal generator generates a high-frequency voltage signal between 16 and 25kHz immediately, and the high-frequency voltage signal is loaded to a piezoelectric ceramic plate of an ultrasonic speaker and is amplified to generate a high-volume ultrasonic wave which is between 16 and 25kHz and has a sound pressure level not lower than 90dB by virtue of the speaker. According to the bird repelling device, the energy acquisition CT is used as a power supply to guarantee stable high-power output, so that all-weather 24-hour uninterrupted large-area bird repelling is guaranteed; and a mode that two ultrasonic speakers are connected in parallel is adopted, and ultrasonic wave with variable frequencies is alternately and continuously generated, so that birds cannot adapt to the ultrasonic wave, and the durability of bird repelling effect is guaranteed.

The invention provides a wave-absorbing weaving piece of a compound bar with carbon filaments arranged in a buckling and extending manner and a preparation method thereof. The wave-absorbing weaving piece is characterized by comprising electromagnetic shielding strips which are woven together, wherein each electromagnetic shielding strip comprises a substrate and at least one of a carbon fibre endless tow existing in a buckling wave shape and a carbon fibre endless tow existing in an extending shape. The preparation method is characterized by comprising the following steps of: preparing an electromagnetic shielding piece; and cutting the electromagnetic shielding piece into long and narrow electromagnetic shielding strips, and weaving the electromagnetic shielding strips into the wave-absorbing weaving piece. The wave-absorbing weaving piece combines the wave-absorbing advantages of a buckling and extending array and the wave-absorbing advantages of a weaving structure periodic array secondary dot matrix, the wave-absorbing weaving piece is convenient and efficient to prepare, and a high electromagnetic shielding effect at the frequency of 0.02-2.0GHz is realized. The wave-absorbing weaving piece can be applicable to a lining material of electromagnetic shielding protective clothing, a light structure building material and an interior material of a vehicle.

The invention relates to a power battery box body, a preparation method thereof and a fiber reinforced composite material and belongs to the technical field of a power battery box body. The power battery box body of the present invention is mainly made of the following raw materials including, by weight, 40 to 65 parts of polymer base materials, 30 to 70 parts of reinforced fibers, 35 to 45 partsof flame retardants, 5 to 10 parts of lubricants, and 1 to 2 parts of fillers, and the reinforced fibers are metallized fibers or metallized fiber fabric. The power battery box body of the invention can be formed in one molding, the production process can be simplified, the cost is low, the yield is high, the power battery box body has a good electromagnetic shielding effect, a heavy metal plate or metal foil is not needed, and the power battery box body does not fail due to the vibration of a vehicle body. In addition, the power battery box body has the advantages of small weight, high strength, good insulation, corrosion resistance and high safety.

The invention relates to a surface treatment method for magnesium alloy. The surface treatment method disclosed by the invention comprises the following steps: (1), polishing and feeding a magnesium alloy component; (2), carrying out pre-treatment, such as acid pickling, ultrasonic treatment, degreasing and activating; and (3), carrying out chemical film-forming treatment, ultrasonic oscillation cleaning and the like under the action of a magnetic field. According to the invention, a film is chemically formed by using a treatment solution mainly containing stannate under the action of the magnetic field, so that the surface treatment method is free from pollution and environment-friendly; the treatment solution can be repetitively used; therefore, the resource is saved; the production cost is reduced; the process is simple; an automatic production line is easily formed; the adhesive force and the anti-corrosion property of a chemical conversion film and the macro-properties of parts formed under the action of the magnetic field are good; the properties are better; a stannate film layer is thinner; the average resistance is less than 0.5 omega; and the surface treatment method for magnesium alloy disclosed by the invention has good electrical conductivity and electromagnetic shielding effect, and is particularly applied to surface protection of magnesium alloy electronic products.

The invention belongs to the technical field of production of a cement board, and particularly relates to a cement board which has an electromagnetic shielding function and is prepared by adopting a semi-dry method. The electromagnetic shielding cement board comprises a material A and a solution B, wherein the material A comprises the following raw materials in parts by weight: 5-70 parts of cement, 5-10 parts of glass fibers, 3-7 parts of silica fume, 5-15 parts of fly ash and 0.3-1.5 parts of polyvinylpyrrolidone. The solution B is prepared from the following raw materials in parts by weight: 90 to 98 parts of water, 1 to 6 parts of silane coupling agent and 0.05 to 0.15 part of Fe3O4-modified graphene oxide. The cement board is low in water content, high in density, low in porosity, lowin water absorption rate, excellent in breaking strength and good in anti-freezing performance, and has good mechanical properties and excellent shielding performance. The product can completely meetthe performance requirements when the cement board is used as a decorative board and an external wall board, and has wide application potential.

The invention provides a corrosion-resistance electromagnetic shielding material. The material is prepared from the following raw materials in parts by weight: 60-100 parts of a plastic substrate, 15-30 parts of isocyanate, 5-10 parts of carbon fibers, 3-8 parts of wood fibers, 5-15 parts of a nano-magnetic metal material, 3-10 parts of silicon dioxide, 2-5 parts of a dispersing agent, 3-10 parts of plasticizer, 2-5 parts of a lubricating agent, 2-6 parts of a coupling agent and 1-3 parts of color masterbatch. The plastic material has excellent electromagnetic shielding effect and excellent corrosion resistance, has good mechanical performance and strong impact resistance, can be used for protecting healthy of human bodies, and is long in service life and simple in preparation method.

The invention provides a waterproof roll with an electromagnetic shielding function. The waterproof roll comprises a body base layer, a first waterproof layer is arranged on the upper surface of the body base layer, a second waterproof layer is arranged on the lower surface of the body base layer, a first conductive rubber layer is arranged on the upper surface of the first waterproof layer, a second conductive rubber layer is arranged on the lower surface of the second waterproof layer, and surface protection layers are arranged on the other surface of the first conductive rubber layer and the other surface of the second conductive rubber layer. The body base layer is a non-woven fabric layer, the first waterproof layer and the second waterproof layer are SBS modified asphalt layers, the first conductive rubber layer and the second conductive rubber layer are made of a graphene/natural rubber nanocomposite, and the surface protection layers are made of PE films. According to the waterproof roll, the adhesiveness between every two layers is high, the preparing process is simple, the electromagnetic shielding effect of the polymer modified asphalt waterproof roll can be greatly improved, the demands of the current building industry and the market are met, and high application value is achieved.

The invention discloses a signal detection cable for a digital substation and manufacturing technology. The signal detection cable includes a protective layer, a buffering layer, an armor layer, an aluminum foil layer, an insulating layer and a conductive core. An outer wall of the conductive core wraps the insulating layer, an outer wall of the insulating layer warps the aluminum foil layer, an outer wall of the aluminum foil layer wraps the armor layer, an outer wall of the armor layer includes the buffering layer, an outer wall of the buffering layer wraps the protective layer, the buffering layer includes a rubber shock absorption layer and buffering holes, the rubber shock absorption layer wraps the outer side of the armor layer, and a plurality of buffering holes are uniformly arranged in the rubber shock absorption layer. Through the arrangement armor layer and aluminum foil layer, two metal shielding layers are formed, a good electromagnetic shielding effect is achieved, external interference signals can be effectively prevented from influencing transmission of data, and safety of data transmission is effectively improved; and through arrangement of the buffering layer, a good buffering effect is achieved, and safety of use is effectively improved.

The invention belongs to the field of electromagnetic shielding functional materials and more particularly to a graphene-based electromagnetic shielding composite material which comprises at least twolayers of graphene films, and a non-graphene spacer layer is arranged between the two layers of graphene films and is used for separating the two layers of graphene films with a certain distance. Themain component of the graphene film layers is graphene with the content of high than 50%, and the graphene film layers adhere to the upper surface and the lower surface of the non-graphene spacer layer. By adhering the graphene film layers of certain thickness on two sides of a substrate material of a sheet material, by setting a certain distance between the two graphene film layers, the electromagnetic shielding effect of the material is improved by using the principle that an electromagnetic wave is repeatedly reflected, absorbed, and attenuated at two interfaces.

The invention relates to the field of electromagnetic shielding materials, and concretely relates to an ionic gel/conductive polymer electromagnetic shielding material, a preparation method thereof, and application of the ionic gel/conductive polymer electromagnetic shielding material in the field of electromagnetic shielding. The ionic gel/conductive polymer composite material is prepared by taking the ionic gel as a solid base material and taking the conductive polymer as a conductive filler. The ionic gel has good electrical conductivity and a good electromagnetic shielding effect. The ionic liquid and the conductive polymer have good compatibility, so that the mechanical property of the composite material is improved. Therefore, the preparation method has the characteristics of simplicity in operation, low cost and the like, and the prepared material has excellent flexibility and electromagnetic shielding effect and has wide application potential.

An artificial graphite/copper composite radiating fin and a preparation method therefor relate to the field of radiation of heat components of electronics and electromagnetic shield. The artificial graphite/copper composite radiating fin comprises a copper foil layer and artificial graphite layers located on the upper and lower sides of the copper foil layer; the copper foil layer comprises a copper substrate and roughened layers located on the upper and lower sides of the copper substrate; a tumor-like copper particle structure is uniformly distributed on the surface of each of the roughened layers; each of the roughened layers is mutually engaged with each artificial graphite layer through the tumor-like copper particle structure; and each artificial graphite layer is formed by roll-pressing fluffy artificial single graphite flakes to be adhered to a release film and paving the film on the copper foil. The preparation method comprises: performing roughening treatment and curing treatment on the cleaned copper foil; roll-pressing the fluffy artificial single graphite flakes to be adhered to the release film, then paving the film on the copper foil, and calendering stepwise so as to obtain the artificial graphite/copper composite radiating fin. The radiating fin provided by the invention has a good heat-conducting performance, an excellent electromagnetic shielding effect and low thermal resistance of the interface between the copper foil and graphite, thereby improving the heat-conducting performance.

The invention relates to a transformer substation. A transformer substation outer shell with fireproof electromagnetic shielding plastic comprises a plastic base body. A conducting fiber layer is buried in the plastic base body. The conducting fiber layer is a fiber layer made of conducting fibers. Perlite particles with the particle size smaller than or equal to 3 mm are buried in the plastic base body. A fireproof mica plate layer is arranged outside the plastid base body. The transformer substation outer shell with the fireproof electromagnetic shielding plastic further comprises a three-dimensional net-shaped structure formed mineral substance ropes in a weaving mode. The three-dimensional net-shaped structure penetrates through the plastic base body and the fireproof mica plate layer. The three-dimensional net-shaped structure made of the mineral substance ropes in the weaving mode is arranged, the connecting strength of parts can be enhanced, and the heat insulation performance can be further improved.

The invention discloses a flame-retardant electromagnetic shielding fabric and a preparation method thereof, and belongs to the technical field of textile materials for electromagnetic protection andpreparation methods thereof. The metalized flame-retardant fiber with good spinnability and flexibility and other flame-retardant fibers are blended and woven to obtain an electromagnetic shielding fabric which is based on the full-flame-retardant fiber and has good high-temperature flame-retardant performance, excellent electromagnetic shielding effect and good wearing comfort at the same time. The fabric and the preparation method overcome the inherent defects that a metal fiber blended fabric is limited in shielding effectiveness and poor in comfort, and a common metallized organic fiber blended fabric is not resistant to high temperature and poor in flame retardance; and the prepared flame-retardant electromagnetic shielding fabric can be used for meeting the electromagnetic protectionrequirements of occasions with higher requirements on electromagnetic shielding, high-temperature flame retardance and wearing comfort, such as radar workstations, naval vessels, airplane cockpits, medical treatment, electric power, mines, petrochemical engineering and the like.

The invention relates to a flexible high-frequency electromagnetic shielding material with a dual-network structure, and a preparation method thereof, and belongs to the technical field of electromagnetic shielding materials. The material comprises, by mass, 3-10 parts of conductive particles, 7-48 parts of insulating lightweight fibers and 32-88 parts of a flexible polymer material. The conductive particles and the insulating lightweight fibers are added to the flexible polymer material in order to construct a conductive network and a fiber network which are interpenetrated in the flexible polymer material, electron migration of the conductive network is used to reflect and absorb electromagnetic waves, and the interfacial multistage reflection and interference of the fiber network are used to lose the electromagnetic waves, so the finally produced material has an excellent electromagnetic shielding effect. Additionally, the use amounts of all the components in the flexible high-frequency electromagnetic shielding material are controlled to ensure that the material have an excellent electromagnetic shielding effect and ensure the improvement of the modulus and the strength of thematerial without significantly reducing the flexibility of the material, so the material can be widely applied to industries.

The invention discloses a composite polymer coating for buildings. The composite polymer coating is characterized by being prepared from the following raw materials in parts by weight: 65 parts of styrene-acrylic emulsions, 9 parts of serpentine powder with grain diameter of 2-5 microns, 7 parts of phosphogypsum powder with grain diameter of 5-10 microns, 1.2 parts of triethanolamine, 2.5 parts of benzene sulfinic acid sodium, 5 parts of zinc stearate, 2 parts of sodium dodecyl benzene sulfonate, 4 parts of praseodymium-neodymium alloy powder with grain diameter of 1-2 microns, 7.5 parts of nanometer ferrous powder with grain diameter of 20-30 microns, and 2 parts of tellurium powder with grain diameter of 2-3 microns. According to the composite polymer coating for buildings, composite functional powder which is prepared from nanometer ferric powder, praseodymium-neodymium alloy powder and tellurium powder are added; therefore, the composite polymer coating has a good electromagnetic shielding effect. The coating is in the frequency range of 100 kHz-1.5GHz, and the shielding efficiency can reach 62-78dB; meanwhile, the composite polymer coating is relatively high in physical performance and heatproof performance, and has a good waterproof effect.

The invention discloses a split level type shielding socket, which comprises a shell, a jack, a plunger ring, an upper insulator and a lower insulator. The jack is fixed in the upper insulator and the lower insulator, and then the upper insulator and the lower insulator are fixed in the shell by the plunger ring; the socket is provided with two metallic shielding layers which can relatively rotate at the joint end of the shell; an elastic resetting device is arranged between the two metallic shielding layers; the two metallic shielding layers are in a free state that hole sites are interlaced and shading mutually when the two metallic shielding layers are separated from a contact pin, thus improving the shielding function of the socket by the interface refection at the dislocation and holes between the two metallic shielding layers. The split level type shielding socket of the invention has the advantages of simple structure, better electromagnetic shielding effect and stable and reliable performance, which is suitable for the application situation of highly reliable electromagnetic shielding when the connector is separated, and the socket can satisfy the requirement of novel equipment.

The invention relates to a polyvinyl alcohol-based carbon aerogel using waste leather as a carbon source, and a preparation method thereof. The preparation method comprises the following steps of: performing circular grinding for 30-60 times on the waste leather through a force chemical reactor, adding processed waste leather ultrafine powder into polyvinyl alcohol aqueous solution to sufficientlystir and mix uniformly, processing through quick cooling by liquid nitrogen and freeze drying by a freeze dryer to obtain a PVA/leather compound aerogel, and finally, performing high-temperature oxygen-free carbonization to obtain the polyvinyl alcohol-based carbon aerogel using the waste leather as the carbon source. According to the invention, the waste leather ultrafine powder can be sufficiently complexed with hydroxyl in PVA in the preparation method, and suitable for being used as the carbon source; furthermore, a multi-layer carbon structure formed by high-temperature oxygen-free carbonization can achieve the effect of enhancing the electromagnetic shielding performance of the obtained carbon aerogel; simultaneously, the preparation method provided by the invention is simple in step and low in cost; and thus, high-value industrial utilization on waste leather materials can be easily realized.

The invention provides an electromagnetic shielding polypropylene composition as well as a preparation method and application thereof. The electromagnetic shielding polypropylene composition comprises the following components in parts by weight: 60 to 80 parts of polypropylene resin, 1 to 5 parts of an MOFs-porous carbon material, 5 to 30 parts of talcum powder, 15 to 20 parts of a toughening agent, and 0.3 to 1 part of a processing aid, wherein the metal center of MOFs in a MOFs-porous carbon material is magnetic metal; the pore diameter of the MOFs-porous carbon material is 0.3 to 0.55 nm; the pore volume is 0.4 to 0.65 cm<3>/g; and the specific surface area is 1200-1700 m<2>/g. By adding the MOFs-porous carbon material, the mechanical property and the electromagnetic shielding effect can be improved, and the MOFs-porous carbon material also has an odor adsorption effect.

The invention provides a door-opening shielding device of a magnetic shielding equipment case/ cabinet. The door-opening shielding device of the magnetic shielding equipment case/ cabinet comprises a cabinet body and an equipment installation framework arranged in the cabinet body, the cabinet body and the equipment installation framework are connected to form a closed equipotential body, and the door-opening shielding device of the magnetic shielding equipment case/ cabinet further comprises conductive fabric arranged between the equipment installation framework and the inner surface of the cabinet body and a shielding spring leaf assembly arranged on the mounting flange surfaces of the equipment installation framework. The shielding spring leaf assembly comprises an upper shielding spring leaf, a lower shielding spring leaf, a left shielding spring leaf and a right shielding spring leaf, wherein the upper shielding spring leaf is arranged on the upper framework mounting flange surface of the equipment installation framework, the lower shielding spring leaf is arranged on the lower framework mounting flange surface of the equipment installation framework, and the left shielding spring leaf and the right shielding spring leaf are arranged on framework mounting flange surfaces of the two sides of the equipment installation framework respectively. The door-opening shielding device of the magnetic shielding equipment case/ cabinet is simple in structure, can be directly improved on an ordinary metal equipment cabinet, has good electromagnetic shielding effectiveness, does not influence the operation of the equipment in the equipment case/ cabinet, and has no influence on the operation performance and heat dissipation effect of the equipment case/ cabinet and the equipment.

The invention belongs to the technical field of chemical water-based coatings, and especially relates to a graphene oxide-reinforced water-based plastic coating and a preparation method thereof. The graphene oxide-reinforced water-based plastic coating has the characteristics of high hardness, good friction resistance, good fingerprint resistance and good chemical resistance necessary for 3C consumer electronic product coatings. The graphene-modified water-based 3C consumer electronic product shell paint provided by the invention also has a good electromagnetic shielding effect. Monolayer graphene oxide with a single-layer ratio of above 99% is reduced at a high temperature to obtain the graphene-modified water-based 3C consumer electronic product shell paint, the graphene has excellent electrical conductivity, and has a good reflection loss to electromagnetic radiation; ferrite powder is a magnetic material with a very high magnetic permeability, and is a commonly used wave absorbingmaterial, and realizes electromagnetic radiation magnetic dielectric radiation loss, the graphene and ferrite powder synergistically provide a good electromagnetic shielding effect, and the introduction of the graphene improves the heat dissipation property of the coating and further ensures the use safety of the 3C consumer electronic product.

The invention provides a current transformer and a manufacturing method thereof. The current transformer is formed by assembling an upper magnetic core, a multi-layer PCB and a lower magnetic core, wherein the upper magnetic core comprises a magnetic core upper panel, a middle column located in the center of the upper panel and two side columns which are in the same direction as the middle column,are parallel to the middle column, are arranged in a mirroring mode and are flush with an edge of the magnetic core upper panel, the lower magnetic core comprises a magnetic core bottom column, a middle column located in the middle of the magnetic core bottom column and two side columns which are parallel to the middle column in the same direction and are symmetrically arranged, the middle columnof the upper magnetic core and the middle column of the lower magnetic core are equal in sectional area and equal in width and section, and the magnetic core panel of the upper magnetic core and themagnetic core bottom column of the lower magnetic core are equal in thickness. The current transformer is advantaged in that only combination of the magnetic core and the multi-layer PCB is provided,and process difficulty is low.