31results about How to "Absorbing frequency band is wide" patented technology

The invention belongs to the technical field of manufacturing radar stealth materials for military aircrafts and particularly relates to a broadband wave-absorbing force bearing composite material adopting a secondary curing process and a preparing method thereof. The material is composed of a wave-transparent foam layer, a wave-transparent skin layer, an electrical loss wave-absorbing layer and a shielding bottom layer. The wave-transparent foam layer is made of an on-sale closed-hole hard organic foam material with the thickness of 2 mm-20 mm; the wave-transparent skin layer is made of a continuous wave-transparent fiber enhancing resin matrix composite material with the thickness of 0.1 mm-4 mm; the electrical loss wave-absorbing layer is made of a wave-transparent fiber cloth enhancing composite material which contains carbon black and is 0.5 mm-5 mm thick; the shielding bottom layer is made of a carbon fiber woven cloth material. According to the broadband wave-absorbing force bearing composite material adopting the second curing process, the wave-absorbing frequency band is wider, electrical performance is stable, and the composite material can be applied to various military targets and used for manufacturing stealth structural members with high broadband stealth performance.

The invention provides resin wave absorption paint, which is prepared from resin, graphene and ferroferric oxide compounded material, dispersing agents, anti-settling agents and solvents. The paint is characterized in that the addition mode of graphene materials in the resin wave absorption paint is creatively changed; firstly, the graphene is compounded with a hard material of ferroferric oxide in the paint to obtain the graphene and ferroferric oxide compounded material; then, the graphene and ferroferric oxide compounding material is combined with the other ingredients to obtain the resin wave absorption paint. The graphene dispersing problem can be better solved; the complete realization of the excellent performance is ensured; the problem of mixing nonuniformity of flexible graphene materials in a paint system is solved; in addition, the uniform dispersion of ferroferric oxide nanometer particles on the surface of the graphene can be realized; the performance is better achieved; more importantly, the specific ingredients are matched to be used, so that the prepared resin wave absorption paint has the advantages of thin film layer, high intensity, strong wave absorption capability, wide wave absorption frequency band and low cost; wide application prospects are realized.

The invention discloses a super-structure honeycomb composite wave-absorbing material, belonging to the technical field of wave-absorbing materials. The invention particularly relates to a honeycomb structure-metamaterial composite wave-absorbing material, which is mainly composed of an upper wave-transmitting skin layer, a middle sandwiched aramid fiber wave-absorbing honeycomb wave-absorbing layer and a bottom metamaterial wave-absorbing layer, wherein the three layers of materials are bonded through an epoxy resin adhesive. The metamaterial wave-absorbing layer is formed by manufacturing ametamaterial array on a printed circuit board, and the metamaterial array is an array formed by diamond-shaped, square, hollow-square-shaped or cross-shaped metal units. A metamaterial wave-absorbingbody and the honeycomb wave-absorbing material are creatively combined, and the broadband wave absorbing performance and the low-frequency wave absorbing function of the super-structure honeycomb composite wave-absorbing material are achieved through the selective wave absorbing function of the metamaterial wave-absorbing body.

The invention discloses an electromagnetic wave absorbing material which relates to an electronic material. The electromagnetic wave absorbing material comprises a wave absorbing glue substrate and a cover layer; and the electromagnetic wave absorbing material is characterized in that an aluminium foil pasting layer is arranged between the wave absorbing glue substrate and the cover layer, the aluminium foil pasting layer is prepared from square aluminum foils which are arranged in a matrix mode, the side length of each aluminum foil is 5-9 mm, and the distance between two adjacent aluminum foils is 1-5 mm. In the invention, the wave absorbing frequency range is greatly expanded nearly without increasing the thickness of a wave absorbing body. Through rationally adjusting the graphic size of each aluminum foil, the electromagnetic wave absorbing material disclosed by the invention is also suitable for rubber plates made of different materials.

The invention provides a preparation method of a wave absorbing material for a medical apparatus. The method comprises the steps of preparation of a vinyl ferrocene-4-vinylaniline-acrylonitrile triblock copolymer, preparation of a polypyrrole tube, preparation of a beta-cyclodextrin surface modified polypyrrole tube and a wave absorbing material and the like; the wave absorbing material for the medical apparatus can efficiently treat electromagnetic pollution, reduce electromagnetic wave damage to the human body and improve the data monitoring accuracy of the medical apparatus, and has wide wave absorbing frequency bands, a good wave absorbing effect and excellent market application prospects.

The invention relates to a metal-wire-loading type electromagnetic wave absorption structure improving the performances of oblique incidence, belongs to the technical field of electronic materials, and especially relates to an electromagnetic wave absorption structure and a method therefor. The structure consists of M*N square wave absorption units, wherein M is the number of rows, N is the number of columns, and the M and N are both natural numbers greater than two. Each square wave absorption unit comprises a metal plate and a magnetic wave-absorption material layer disposed on the metal plate, wherein the interior of the wave-absorption material layer is provided with a metal wire, and the direction of the metal wire is parallel to a side of the square wave absorption unit. Moreover, the directions of the metal wires of all the square wave absorption units are the same, and the lengths of the metal wires are less than the side lengths of the square wave absorption units. The structure can enlarge the wave-absorption frequency band under different incidence angles under the condition of reducing or increasing the thickness of the structure.

The invention relates to a skin scraping plate. The skin scraping plate is prepared from the following raw materials in part by weight: 60 to 70 parts of Fe2O3, 16 to 24 parts of ZnO, 5 to 15 parts of Ni2O3, 3 to 6.8 parts of CuO, 0.1 to 0.8 part of Bi2O3, 0.2 to 0.8 part of V2O5, 0.1 to 0.2 part of Nb2O5 and 0.1 to 0.5 part of Co2O3. The invention also relates to a method for manufacturing the skin scraping plate. A skin scraping plate crystal structure is stable and reliable, has high wave-absorbing property and wide wave-absorbing frequency band and has the effects of protecting from electromagnetic radiation and protecting human health. The skin scraping plate has a health-care function. Therefore, the skin scraping plate integrates an ornament, a skin scraping plate and an electromagnetic radiation-resistant product, wherein the functions are not influenced mutually.

The invention discloses an electromagnetic wave-absorption radiation-protection magnetic-health composite material and a mouse mat, and relates to a substance composition of an electromagnetic wave absorption material, a preparation method of the composite material, and a making method of the mouse mat. The composite material has multiple functionalities, and has very good health effects on the improvement of people's life and work environment and the improvement of people's body heath. The composite material has the advantages of strong practicality, wide use, wide prospect, and good economic and social benefits.

The invention discloses a metamaterial wave-absorbing structure applied to a millimeter wave radar, and a vehicle antenna thereof. The wave-absorbing structure comprises a plurality of square wave-absorbing units which are periodically and tightly arranged in the horizontal direction, each wave-absorbing unit comprises a metal reflecting layer, a first dielectric layer, a metasurface layer and a second dielectric layer which are sequentially stacked from bottom to top, the metal reflecting layer, the first dielectric layer and the second dielectric layer are all in a square sheet shape with the side length being p, the metasurface layer comprises two large circular wave absorbing plates and two small circular wave absorbing plates, the distance between the circle center of each large circular wave absorbing plate and the two sides of the corresponding right angle on the first dielectric layer is p/4, and the distance between the circle center of the small circular wave absorbing plate and the two sides of the corresponding right angle on the first dielectric layer is p/4. The wave-absorbing structure can reduce the back scattering waveform of the antenna, so that when the radar is installed in a vehicle, the wave-absorbing structure absorbs the back scattering wave of the radar, the multipath effect of the radar is reduced, and the working efficiency of the radar is improved.

The invention belongs to the technical field of wave absorbing materials, and particularly relates to a preparation method of a graphene-based wave absorbing material. The preparation method of the graphene-based wave absorbing material comprises the following technological steps: 1) dissolving cobalt metal salt, ammonium fluoride and urea into water to obtain a metallic salt aqueous solution; 2)putting the metallic salt aqueous solution obtained in the step 1) into a hydrothermal kettle; 3) adding graphene into a stannous chloride solution, performing sensitization and activation in sequence, performing filtration and washing to form a neutral state by using deionized water, so as to obtain pre-treated graphene; 4) adding the pre-treated graphene prepared in the step 3) into the metallicsalt aqueous solution prepared in the step 2); (5) heating and drying an alkali type carbonate/graphene material obtained in the step 4), and then performing calcination to obtain a graphene composite wave absorbing material product. The preparation method of the graphene-based wave absorbing material has the beneficial effects that a wave absorbing frequency band is wide, the operability is strong, a preparation condition is mild, a reaction process is clean and free of pollution, the reaction efficiency is high, the reproducibility is good, and the graphene-based wave absorbing material hasgreater synthesis application prospect.

The invention discloses a high-temperature resistant wave-absorbing coating and a preparation method and application thereof. The high-temperature resistant wave-absorbing coating mainly comprises a high-temperature resistant wave-absorbing filler, silica sol, nano-silica dispersion, an acidic medium, glass powder, ethylene glycol, a dispersant, an anti-settling agent, siloxane and the like, wherein the high-temperature resistant wave-absorbing filler comprises Fe3O4-graphene- SiO2 composite nanoparticles. The high-temperature resistant wave-absorbing coating can be naturally dried at room temperature, and can resist high temperature of 100-400 DEG C for a long time, and a formed coating layer has good adhesion with a substrate, high hardness, wide wave-absorbing frequency band, and excellent corrosion resistance and salt fog resistance.

The invention relates to a wave-absorbing material with a three-layer hollow structure as well as a preparation method and application thereof, and belongs to the technical field of wave-absorbing materials. The wave-absorbing material with the three-layer hollow structure has various loss modes such as magnetic loss, resistance loss and dielectric loss, so that the wave-absorbing frequency band of the particle is wider, and the wave-absorbing performance is better. According to the wave-absorbing material with the three-layer hollow structure, due to the existence of the multi-layer structureand the interlayer walls, the wave-absorbing performance of the three-layer hollow nanoparticles is improved.

The invention discloses a broadband-adjustable non-reflection wave-absorbing device and a wave-absorbing method. The broadband-adjustable non-reflection wave-absorbing device comprises a pumping layer and a wave-absorbing layer arranged on the pumping layer, and the wave-absorbing layer comprises a wave-absorbing material; the pumping layer is used for generating pumping laser; the wave-absorbing layer is used for receiving the pumping laser, inducing free carriers in the wave-absorbing material through the pumping laser, and changing the relative dielectric constant of the wave-absorbing material through the free carriers, so that the wave-absorbing material meets a preset impedance matching condition; and the wave absorbing layer is also used for receiving incident electromagnetic waves and absorbing the incident electromagnetic waves when the wave absorbing material meets a preset impedance matching condition. According to the wave-absorbing device, the free carriers are induced in the wave-absorbing material through the pumping laser, the relative dielectric constant of the wave-absorbing material is changed through the free carriers, the electromagnetic wave-absorbing function of the wave-absorbing device is achieved, the light intensity of the pumping light can be adjusted according to the frequency of incident electromagnetic waves, the working frequency can be adjusted from microwaves to far infrared rays. And the wave-absorbing frequency band is wide and the working bandwidth is long.