52results about How to "Improve absorbing ability" patented technology

The present invention provides a wave absorbing material, which comprises one layer resin glue film or multiple layer resin glue films, and one-layer carrier or multiple layer carriers, wherein the resin glue film comprises 50-200 parts of a resin and 50-150 parts of a filler, the one layer resin glue film or multiple layer resin glue films and the one-layer carrier or multiple layer carriers are alternately placed, and the filler comprises a wave absorbing agent. The present invention further provides a wave absorbing material preparation method. According to the present invention, the wave absorbing material and the object requiring good wave absorbing capability are combined, such that the defect that only the coating or sheet adhering way can be used to preparing the wave absorbing material in the prior art is effectively solved; the wave absorbing material has characteristics of light weight and strong wave absorbing ability; and the fiber compounding way is used, such that the prepared wave absorbing material has good wave absorbing ability and good mechanical property.

The invention relates to multilayer-structure radar wave-absorbing cloth and a preparation method thereof. The multilayer-structure radar wave-absorbing cloth is mainly used for production of gun covers, tank outer covers, vehicle canvases, camping tents, camouflage nets and other military use fields, and includes a substrate canvas, wave-absorbing material layers and adhesion agent layers; the wave-absorbing material layers are respectively pasted on the substrate canvas through the adhesion agent layers in a superimposed mode, and the surface of the outermost layer of the wave-absorbing material layers is also provided with the adhesion agent layer. The wave-absorbing material layers are wave-absorbing coating layers, wherein a wave-absorbing coating is a polyurethane coating containing a magnetic metal alloy micropowder, and the magnetic metal alloy micropowder of the wave-absorbing material layers comprises the components by mass percentage: 85%-95% of Fe, 0.5%-5% of Cr, 0.1%-3% of Si, and 0.05%-7% of Al. The wave-absorbing cloth has the advantages of strong wave-absorbing ability, wide wave-absorbing frequency band, water proof, gas permeation, flame retardance.

The invention provides a method of preparing an electromagnetic wave absorber. The method comprises the following steps: carrying out a ball milling technology carbonyl iron powder; carrying out surface treatment on the ball-milled carbonyl iron powder by using strong base; treating the carbonyl iron powder by virtue of a titanium-containing compound to obtain carbonyl iron-TiO2 core-shell-structured microparticles; and magnetizing the carbonyl iron-TiO2 core-shell-structured microparticles. The electromagnetic wave absorber is prepared from the following components in percentage by weight: 10-60 percent of modified carbonyl iron powder and 40-90 percent of a coating material. The electromagnetic wave absorber prepared by virtue of the method is capable of effectively showing good electromagnetic wave absorption capability in multiple frequency bands; compared with the prior art, the electromagnetic wave absorber is wide in electromagnetic wave absorption frequency band.

The invention belongs to the field of composite material manufacturing and structure microwave-absorbing materials, and relates to a microwave-absorbing composite material with a discontinuous impedance gradient structure. A five-layer discontinuous impedance gradient structure comprising a wave-transparent layer, a low-concentration electrical loss layer, another wave-transparent layer and a high-concentration electrical loss layer and yet another wave-transparent layer is adopted; the used absorbent is electrical loss absorbent short carbon fibers; a mixed liquid is sprayed on quartz glass fiber cloth by adopting a spraying technology; and the short carbon fibers are uniformly distributed. An impedance gradient structure design is adopted by the electrical loss microwave-absorbing composite material, impedance matching can be achieved and an absorption band is effectively expanded. The short carbon fibers have the advantages of light weight, diversified loss mechanism and relatively high electromagnetic wave loss ability as an electrical loss absorbent, and the weight of the microwave-absorbing composite material is not increased. The designed and manufactured microwave-absorbing composite material has good micro-wave absorbing ability on X and KU bands.

The invention relates to an ultra-high frequency (UHF) radar frequency spectrum shifting method of a frequency selective surface (FSS)-based multi-layer reflective modulation plate, and belongs to thetechnical field of electromagnetic field microwave. By means of electromagnetic characteristic controllability of an electromagnetic metamaterial, an FSS-based three-layer structured reflective modulation plate is designed, dynamic conversion of a transient characteristic impedance state is achieved, so that the electromagnetic characteristic such as margin and phase of a low-frequency radar incident wave and a reflective wave direction are changed, and the problem of frequency spectrum shift of an UHF radar incident wave and receiver signal detection are solved. The three-layer reflective modulation plate is designed on the basis of FSS, conversion between a high-impedance state and a low-impedance state of a surface of an active layer is controlled, and two-phase constant-mode modulation of the radar incident signal is achieved; and meanwhile, based on a transmission line principle, an equivalent circuit of an adjustable reflective modulation plate is designed and has ideal wave absorption capability, and frequency spectrum shift of the UHF frequency radar signal is achieved.

A method for producing vegetable oil fuel with low viscosity, including a transesterification step P1 with respect to vegetable oil with triglyceride structure having unsaturated fatty acid, an ozone treatment step P2 with respect to unsaturated fatty acid methyl ester generated in the transesterification step P1, and a reduction step P3 with respect to the ozonide generated in the ozone treatment step P2.

The invention relates to the field of wireless communication, and particularly to a two-phase modulating board for performing radar spectrum shifting and a method thereof. The two-phase modulating board comprises a frequency selection surface (FSS), a medium spacing layer and a metal grounding layer. The two-phase modulating board is constructed through setting a three-layer adjustable-frequency reflection modulation board based on the FSS. The FSS is constructed to an adjustable resistor, a capacitor and an inductor. A mathematical model is established by means of a dynamic transmission line equivalent circuit. The spectrum shifting on a two-phase modulating surface is researched according to the mathematical model. When the two-phase modulating surface is in a high-impedance state and a low-impedance state, an average reflection coefficient in a time period is 0, and energy of a radar reflection echo is shifted to a sideband. On other conditions, multiple reflections occur in the modulating board, thereby changing the frequency response characteristic of a system. The two-phase modulating board provided by the invention can shift the energy of the reflection echo to the sideband and furthermore performs functions of reducing a reflection coefficient and realizing high wave absorbing capability.

The invention belongs to the technical field of electromagnetic wave absorbing materials, and discloses a Ni / NiO-C composite material with a porous structure as well as a preparation method and application thereof. The composite material comprises carbon spheres and Ni / NiO composite particles attached to the surfaces of the carbon spheres, micropores are distributed in the surfaces of the carbon spheres, and the Ni / NiO composite particles are flower-shaped. The preparation method comprises the following steps: adding glucose, water-soluble nickel salt and urea into water, and uniformly stirring; controlling the temperature of the obtained solution at 170-190 DEG C, standing and carrying out hydrothermal reaction for 15-18 hours; after the hydrothermal reaction is finished, taking out precipitates, cleaning and drying to obtain a precursor; and in an inert or protective atmosphere, controlling the temperature of the precursor to be 400-800 DEG C, and calcining for 2-3 hours to obtain acalcined product, namely the Ni / NiO-C composite material with the porous structure. The prepared Ni / NiO-C composite material has a better electromagnetic wave absorption characteristic, and can be widely applied to the corresponding fields of electromagnetic protection and microwave stealth as an electromagnetic wave absorption material.

The invention provides Fe2O3@MXene composite powder and a preparation method thereof. The preparation method of the Fe2O3@MXene composite powder comprises the following steps that step one, Fe2O3 is mixed with MXene powder with the molar ratio of (1-3) to 1, and a mixture is stirred thermostatically at room temperature to intensive mixing; and step two, a mixed composite material is placed under the room temperature condition for drying to constant weight, and the Fe2O3@MXene composite powder is obtained; the Fe2O3 is mixed with the MXene powder, more Fe2O3 nano-particles are attached to layered edges of the MXene composite powder, the particle sizes of the Fe2O3 nano-particles are uniform and no agglomeration phenomenon generates, and the uniformity of interlayer spacing of the MXene powder is better; the Fe2O3 nano-particles are doped in the MXene powder, so that a real part Epsilon' and an imaginary part Epsilon'' of a dielectric constant are reduced, a real part Mu' and an imaginary part Mu'' of the magnetic conductivity are risen, and a loss tangent value tan Delta is risen; and the composite material of the Fe2O3 nano-particles are doped in the MXene powder, so that the reflectivity loss is reduced, the largest absorption peak can move to low frequency, and it means that the wave-absorbing capacity is improved. The preparation method of the Fe2O3@MXene composite powder islow in cost, short in production period and environmentally friendly.

The invention belongs to the technical field of electromagnetic wave absorbing materials, and discloses a core-shell structure C@CoNi composite material as well as a preparation method and applicationthereof. The composite material is a core-shell structure formed by uniformly wrapping several CoNi alloy particles around a carbon sphere, and the CoNi alloy particles are in a flower-like structure. The preparation method comprises the following steps of adding glucose and hexadecyl trimethyl ammonium bromide into water, and uniformly stirring; carrying out standing hydrothermal reaction on theobtained solution at a temperature of 180-200 DEG C for 12-15 hours; after the hydrothermal reaction is finished, taking out precipitate, and cleaning and drying to obtain a precursor carbon sphere;dispersing the carbon sphere, water-soluble cobalt salt, water-soluble nickel salt and hydrazine hydrate in water, and uniformly stirring; carrying out standing hydrothermal reaction on the obtained solution at a temperature of 160-180 DEG C for 15-18 hours; and after the hydrothermal reaction is finished, taking out precipitate, and cleaning and drying to obtain the core-shell structure C@CoNi composite material. The C@CoNi composite material of the prepared core-shell structure has good electromagnetic wave absorption characteristics.

The invention provides a strontium titanate / polypyrrole nanocomposite fiber with a one-dimensional core-shell structure, and a preparation method thereof. The nanocomposite fiber is composed of a polymer polypyrrole body and a barium strontium titanate nanofiber material, and the barium strontium titanate nanofiber is coated with the polypyrrole to form the core-shell structure. The barium strontium titanate / polypyrrole nanocomposite fiber with the core-shell structure is prepared by an electrospinning process combined gas phase polymerization technology, and the core-shell structure of the barium strontium titanate / polypyrrole nanocomposite fiber is formed by adopting barium strontium titanate as a hard template and polyvinylpyrrolidone as a soft template in the polymerization process. The one-dimensional fibrous wave absorbing material has obvious better wave absorbing ability than a spherical wave absorbing material, the shell thickness of the composite fiber is controllable, and the material of the shell has good electrical conductivity, so the expansion of the wave absorbing band of the composite material is benefited, and the composite nanofiber has the advantages of good one-dimensional morphology, uniform size distribution, good dispersion stability, and simple and easy preparation process.

The invention discloses a preparation method of a ZnSnO3@rGO composite material. The preparation method comprises the following steps: 1) adding a dried graphene sheet and potassium permanganate intoa strong H2SO4 / H3PO4 mixed solution respectively, stirring at a constant temperature of 50 DEG C for 12 hours, cooling to room temperature, adding the reaction solution into ice containing 30 percentof H2O2, filtering after the color of the mixture changes to luminous yellow to obtain graphene oxide, washing with hydrochloric acid to remove metal ions, and performing vacuum freeze drying for 24 hours; 2) adding the prepared graphene oxide into a beaker filled with deionized water, performing ultrasonic treatment for 24 hours, adding SnCl4.5H2O and Zn(NO3)2.6H2O which are equal in molar mass respectively, performing magnetic stirring, adding 24 percent by weight of ammonia water into the reaction mixture dropwise, continuously stirring till the pH value is 9, heating the mixed solution ata temperature of 130 DEG C for 15 hours, washing with distilled water and ethanol respectively to obtain black powder particles several times, and drying the black powder particles to obtain a ZnSnO3@rGO composite material. The prepared composite material has the advantages of small thickness, good wave absorbing effect and wide absorbing wave band.

The present invention relates to an inkjet recording sheet for forming an image using aqueous pigment ink comprising: a substrate; and an ink-receiving layer formed on the substrate, wherein the ink-receiving layer is obtained by applying, on the substrate, a coating composition containing: a cationic acrylic silicone emulsion-based resin having a hydrolyzable silyl group as a crosslinking component; a cationic polyether-based urethane resin; and a carbodiimide group-containing resin, followed by curing the applied coating composition, and wherein, in the coating composition, the content of the cationic acrylic silicone emulsion-based resin is 2 to 7% by mass, the content of the cationic polyether-based urethane resin is 88 to 94% by mass, and the content of the carbodiimide group-containing resin is 2 to 6% by mass in terms of solid matter.

The invention discloses a graphene-containing lightweight anti-electromagnetic pollution composite material plate and a preparation method thereof. The lightweight wave absorbing multi-layered composite plate is prepared through the following steps that a, graphene, nanosized ferrite, sendust and a foaming agent are mixed and added into a thermosensitive bag material and subjected to spray drying,and three kinds of microcapsules are obtained; b, the three kinds of microcapsules are mixed with polyolefin and a processing assistant, and three kinds of first polyolefin compositions are obtained;and c, the compositions are added into a three-layer co-extrusion machine, extrusion and overlaying are conducted, and the lightweight wave absorbing composite plate with the three-layer structure isprepared. The method has the following beneficial effects that the gas generated in the extrusion and foaming processes of each layer is subjected to secondary dispersion, so that a microwave absorbent is uniformly dispersed in a polymer, and the obtained lightweight composite plate with the three-layer structure has the excellent wave absorbing capability, and the outstanding damping propertiessuch as damping and wave absorbing.

The invention discloses an electromagnetic wave absorbing material prepared on the basis of MXene waste precipitates as well as a preparation method and application of the electromagnetic wave absorbing material, and belongs to the technical field of nano materials and electromagnetic wave absorbing materials. The invention provides an electromagnetic wave absorbing material obtained on the basis of MXene waste precipitates, which is obtained by taking the MXene waste precipitates left after MXene is prepared by MAX phase etching as raw materials, collecting, drying and carbonizing. The carbonization treatment comprises the steps of putting the dried MXene waste precipitates into a crucible, putting the crucible into a tubular furnace, and carbonizing for 1-5 hours at the temperature of 400-1000 DEG C in an N2 atmosphere so as to obtain the electromagnetic wave absorbing material. The invention also provides a preparation method and application of the electromagnetic wave absorbing material. The method disclosed by the invention is simple, secondary utilization is performed on the MXene waste precipitate, and the wave-absorbing performance and the wave-absorbing bandwidth of the wave-absorbing material are effectively improved.

The invention discloses a preparation method of a nickel-iron-zirconium compound ferrite. The preparation method comprises the specific steps of mixing nickel salt, iron salt and zirconium salt solutions together, and then carrying out titration by use of an alkali liquor under an ultrasonic condition for precipitating, and filtering, drying and sintering at a high temperature the precipitate, thereby obtaining the nickel-iron-zirconium compound ferrite. The compound ferrite shows excellent wave absorbing capacity; all the components are mixed more evenly.

The invention provides silicon carbide polycrystalline shell-core wave-absorbing particles with graphene on the surface, and a preparation method and an application thereof in textile finishing. The particular preparation method comprises the steps: fully immersing a graphite paper electrode in concentrated sulfuric acid, and carrying out ultrasonic treatment to obtain a pretreated graphite paperelectrode; carrying out an electro-hydrolysis reaction of the pretreated graphite paper electrode in a dilute sulfuric acid solution with the voltage of 5-8 V, taking out the graphite paper electrode,carrying out ultrasonic wave washing of the graphite paper electrode with water, and dispersing to obtain a graphene oxide solution; adding polycarbosilane into the graphene oxide solution, then fully impregnating, taking out the product, drying, and thus obtaining graphene oxide pretreated polycarbosilane; and placing the graphene oxide pretreated polycarbosilane in a horizontal tubular furnace,carrying out heat treatment at the temperature of 1250-1400 DEG C, and thus obtaining the silicon carbide polycrystalline shell-core wave-absorbing particles with graphene on the surface. The siliconcarbide polycrystalline shell-core wave-absorbing particles with graphene on the surface are mixed with auxiliary agents to form a wave-absorbing textile finishing solution, and the wave-absorbing textile finishing solution is adhered to the surface of textile base cloth to form a wave-absorbing coating layer by a coating, impregnation or spraying process.

The invention provides a cement-based conductive composite material, and relates to the technical field of cement materials. The cement-based conductive composite material comprises the following components by weight: 80-100 parts of cement; 110-140 parts of fly ash; 80-100 parts of silica fume; 70-120 parts of water; 1-5 parts of a water reducing agent; 10 to 15 parts of rubber powder; 1-5 partsof steel fibers; 1-3 parts of carbon fiber; 1-3 parts of polyvinyl alcohol fiber; and 30-50 parts of ferrite. The invention also provides a preparation method of the cement-based conductive compositematerial, which comprises the following steps of: uniformly mixing the cement, the fly ash, the silica fume and the rubber powder; adding the water, the steel fibers, the carbon fibers, the polyvinylalcohol fibers, the ferrite and the water reducing agent, and stirring for 5-10 minutes; pouring the mixture into a mold, and vibrating for 1-3 minutes; pressurizing to remove bubbles, strickling thesurface, and maintaining for 24-36 hours; and carrying out demolding maintenance for 28-30 days. The material disclosed by the invention has a relatively strong electromagnetic wave absorption function in a wide frequency range, and has relatively good compressive strength.

The invention discloses a preparation method of ammonium nitrate assisted macroporous thin-layer carbon, which comprises the following steps: by using glucose as a carbon source and zinc nitrate as acomplexing pore-forming agent, dissolving different amounts of zinc nitrate and glucose in deionized water at room temperature to form a uniform mixed solution; and then obtaining the high-specific-capacitance macroporous thin-layer carbon through caramelization reaction, carbonization treatment and acid pickling. The preparation method of the high-specific-capacitance macroporous thin-layer carbon is green and environment-friendly, and the preparation process is simple. The method belongs to the technical field of preparation of novel carbon materials, and the carbon material prepared by themethod has high specific capacitance and high specific surface area as a supercapacitor electrode material, and has important application prospects in the fields of national defense science and technology, aerospace and the like.

The invention discloses an aircraft anti-radar stealth material and a preparation method thereof, and belongs to the technical field of functional materials. The stealth material comprises a reflecting layer and an absorbing layer which are sequentially arranged from outside to inside, and the reflecting layer is prepared from, by weight, 30-70 parts of epoxy resin and 10-35 parts of aluminum foil and gold scraps. The aircraft anti-radar stealth material is of a double-layer structure, the outer reflecting layer and the inner absorbing layer both have good wave absorbing capacity, and the anti-radar stealth capacity of the material is greatly improved.

The invention discloses an environment-friendly purifier for soldering tin smoke. The environment-friendly purifier comprises a purifying tank (1), a gas inlet pipe (2) penetrating through a top plate of the purifying tank (1) and stretching into the purifying tank (1), and at least one exhaust pipe (3) communicated with the purifying tank (1). The outer wall of the gas inlet pipe (2) is connected with the top plate of the purifying tank (1) in a sealed mode. The end face of the gas outlet end of the gas inlet pipe (2) is concaved inwards to form a concave cavity (2.1), and the outer wall of the gas inlet pipe (2) surrounds the cavity wall of the concave cavity (2.1) to form a cavity (2.2); a plurality of exhaust holes are formed in the cavity wall of the concave cavity (2.1). The environment-friendly purifier has the advantages of being capable of being miniaturized, high in purifying efficiency, convenient to maintain, easy to use, environmentally friendly and capable of saving energy.

The invention discloses a babylonia (gastropod) fattening feed. The invention is characterized in that the babylonia fattening feed is prepared from the following raw materials in parts by weight: 22-28 parts of bean curd residues, 23-25 parts of soybean powder, 20-25 parts of wheat bran, 20-25 parts of Chinese yams, 12-16 parts of oat, 40-50 parts of kelps, 13-15 parts of sea worms, 23-24 parts of salmon meat, 18-21 parts of ribbon fishes, 30-35 parts of freshwater snail meat, 26-30 parts of fish meal, 17-19 parts of egg yolks, 14-18 parts of avocados, 9-13 parts of pumpkin seeds, 13-16 parts of carrots, 12-15 parts of bananas, 9-15 parts of freshwater mussel meat, 15-18 parts of egg shell powder, 6-8 parts of protein powder, 3-5 parts of bone calcium powder, 3-4 parts of yeast dextran, 3-4 parts of vitamin E and 3-5 parts of health-preserving traditional Chinese medicine liquid. The raw materials of the aquaculture feed for culturing the babylonia are easy to obtain; and the prepared feed is high in nutritive values, good in babylonia adaptabilities and strong in absorbing properties for the babylonia; thus, the babylonia in the fattening period is improved in size and meat texture, and the aquaculture benefits are thereby improved. Moreover, the traditional Chinese medicine ingredients are added so as to ensure cleanliness of the water, so that the babylonia is not liable to get sick.

The invention discloses a device used for tin soldering flue gas purification. The device comprises a purification box (1), a gas inlet pipe (2) penetrating through a top plate of the purification box (1)to extend into the purification box (1), and at least one gas outlet pipe (3) communicated with the purification box (1), wherein the outer wall of the gas inlet pipe (2) is hermetically connected with the top plate of the purification box (1); the end surface of the gas outlet end of the gas outlet pipe (2) is inwards recessed to form a recessed cavity (2.1); the outer wall of the gas inlet pipe (2) surrounds the cavity wall of the recessed cavity (2.1) to form a cavity (2.2); and a plurality of gas outlets are formed in the cavity wall of the recessed cavity (2.1). The device has the advantages that the device can be miniaturized, the purification efficiency is high, the device is maintained conveniently, the use is simple, and the device is environment-friendly and energy-saving.

The invention discloses a soldering tin smoke purifier. The soldering tin smoke purifier comprises a purifying tank (1), a gas inlet pipe (2) penetrating through a top plate of the purifying tank (1) and stretching into the purifying tank (1), and at least one exhaust pipe (3) communicated with the purifying tank (1). The outer wall of the gas inlet pipe (2) is connected with the top plate of the purifying tank (1) in a sealed mode. The end face of the gas outlet end of the gas inlet pipe (2) is concaved inwards to form a concave cavity (2.1), and the outer wall of the gas inlet pipe (2) surrounds the cavity wall of the concave cavity (2.1) to form a cavity (2.2); a plurality of exhaust holes are formed in the cavity wall of the concave cavity (2.1). The soldering tin smoke purifier has the advantages of being capable of being miniaturized, high in purifying efficiency, convenient to maintain, easy to use, environmentally friendly and capable of saving energy.

The invention discloses a device used for tin soldering flue gas purification. The device comprises a purification box (1), a gas inlet pipe (2) penetrating through a top plate of the purification box (1)to extend into the purification box (1), and at least one gas outlet pipe (3) communicated with the purification box (1), wherein the outer wall of the gas inlet pipe (2) is hermetically connected with the top plate of the purification box (1); the end surface of the gas outlet end of the gas outlet pipe (2) is inwards recessed to form a recessed cavity (2.1); the outer wall of the gas inlet pipe (2) surrounds the cavity wall of the recessed cavity (2.1) to form a cavity (2.2); and a plurality of gas outlets are formed in the cavity wall of the recessed cavity (2.1). The device has the advantages that the device can be miniaturized, the purification efficiency is high, the device is maintained conveniently, the use is simple, and the device is environment-friendly and energy-saving.

The invention discloses a smoke absorbing and purifying system of a ventilation cabinet. The smoke absorbing and purifying system comprises a purification tank (1), an air inlet pipe (2) penetrating a top plate of the purification tank (1) and stretching into the purification tank (1), and an exhaust pipe (3) communicating with the purification tank (1). The outer wall of the air inlet pipe (2) and the top plate of the purification tank (1) are in sealed connection. The end face of the air outlet end of the air inlet pipe (2) is inwards concaved to form a columnar concave cavity (2.1). The outer wall of the air inlet pipe (2) surrounds the cavity wall of the columnar concave cavity (2.1), and a cavity (2.2) is formed. The smoke absorbing and purifying system has the beneficial effects that the purification efficiency is high, the purification effect is good, maintaining is convenient, and using is simple.

The invention relates to the field of wireless communication, and particularly to a two-phase modulating board for performing radar spectrum shifting and a method thereof. The two-phase modulating board comprises a frequency selection surface (FSS), a medium spacing layer and a metal grounding layer. The two-phase modulating board is constructed through setting a three-layer adjustable-frequency reflection modulation board based on the FSS. The FSS is constructed to an adjustable resistor, a capacitor and an inductor. A mathematical model is established by means of a dynamic transmission line equivalent circuit. The spectrum shifting on a two-phase modulating surface is researched according to the mathematical model. When the two-phase modulating surface is in a high-impedance state and a low-impedance state, an average reflection coefficient in a time period is 0, and energy of a radar reflection echo is shifted to a sideband. On other conditions, multiple reflections occur in the modulating board, thereby changing the frequency response characteristic of a system. The two-phase modulating board provided by the invention can shift the energy of the reflection echo to the sideband and furthermore performs functions of reducing a reflection coefficient and realizing high wave absorbing capability.