320 results about "Surface bonding" patented technology

The present application belongs to the technical field of mass concrete construction, and aims to solve the problem of high thermal resistance and slow heat dissipation of traditional cooling pipe laminar bottom layer, and discloses a gravity dam construction cooling water pipe based on destruction of laminar bottom layer and a method thereof. The cooling water pipe comprises a plurality of series water pipe units, each water pipe unit comprises a steel pipe, a flexible spring hose is arranged in the steel pipe, and the spring hose forms a spiral protruding turbulence structure along the inner wall of the steel pipe; the hose is fixed by pointwise anchoring and outer wall surface bonding with glue, and a ring is arranged at both ends for limiting and assisting turbulence. The present application breaks through the thermal resistance of laminar bottom layer, greatly improves the hydration heat conduction efficiency, is convenient to construct and has durable structure, and is suitable for mass concrete temperature control requirements.

The invention relates to a bonding structure and a preparation method thereof, and a light-emitting assembly and a manufacturing method thereof. The preparation method of the bonding structure comprises the following steps: providing a growth substrate; wherein a sacrificial layer with a preset thickness is epitaxially grown on the growth substrate; carrying out patterning processing on the sacrificial layer so as to expose a part of the surface of the growth substrate; manufacturing a flat layer on the exposed surface of the growth substrate and the surface of the sacrificial layer; bonding a first temporary substrate on the surface of the flat layer; dissociating the sacrificial layer to weaken the connection between the growth substrate and the flat layer; filling a bonding adhesive material at the position of the dissociated sacrificial layer; wherein the surface of the bonding glue material is flush with the surface of the flat layer; and bonding a second temporary substrate on one side, deviating from the first temporary substrate, of the bonding glue material, and removing the flat layer. By applying the technical scheme, the residue of the bonding glue material can be reduced, and the bonding yield is ensured.

This application relates to the field of printed circuit board processing technology, and more specifically, to a low-electrical-loss copper bonding compound, its preparation method, and its application. The compound has the following structural formula: a polythiourea molecule with a nitrazole structure, wherein the degree of polymerization n is 3-10. This application benefits from the compound's special structure (C=S and -NH2), effectively achieving bonding under copper-free etching conditions, and the smooth copper surface meets the requirements for high-frequency signal transmission.

The invention provides a phased array ultrasonic interface debonding detection method for a multilayer curved surface bonding structure, which comprises the following steps of: accurately calculating delay time of each array element in a phased array ultrasonic probe to a target focus by designing a delay block attached to a solid engine and aiming at a cylindrical special structure; therefore, in-phase superposition of sound waves at the target focus is achieved, focusing of sound beams is achieved, the problem of delay time calculation of sound waves emitted by all array elements of a phased array probe of a cylindrical structure is solved, and the problem of control over the deflection angle and the focusing depth of the sound beams synthesized after the sound waves pass through a plurality of curved surface interfaces is solved. Accurate positioning and visual representation of the debonding defect of the deep interface are realized. The technology provides a new technical means for accurately judging the interface debonding defect, and has important significance for guaranteeing the structural integrity and the use safety of the interface debonding defect.

The utility model discloses a printed circuit board element mounting device, and particularly relates to the technical field of circuit board processing, which comprises a three-axis moving platform, eight fixing blocks are fixedly connected in the three-axis moving platform, rotating shafts are rotatably connected in the two fixing blocks on the front side and the two fixing blocks on the rear side, and the rotating shafts are connected in the three-axis moving platform. And fixing rods and a lifting assembly are fixedly connected into the two fixing blocks located on the left side and the two fixing blocks located on the right side correspondingly, and the lifting assembly comprises two first stepping motors fixedly connected to the left side and the right side of the bottom of the three-axis moving platform. According to the utility model, the three-axis mobile platform, the solder paste extruder, the camera and the air supply pipe are arranged, so that the device can automatically finish the work of solder paste smearing, surface mounting and heating reflow soldering on a PCB surface bonding pad, the device can realize complete automation, the situation that manual interference is still needed in the surface mounting process is avoided, and the production efficiency is improved. And the working efficiency of the device is improved, and further use by workers is facilitated.

The invention discloses a method for improving the surface bonding strength of an ultra-high-temperature ceramic coating through additive coarsening, and belongs to the technical field of ceramic coating preparation. Bonding layer slurry is arranged on the surface of the ultra-high-temperature ceramic coating to obtain a bonding layer, then rough layer slurry is arranged on the surface of the bonding layer to be coarsened to obtain a rough layer, and the rough layer is prepared into the ultra-high-temperature ceramic coating through additive coarsening. The maximum height difference Ry of the surface in the rough layer is controlled to range from 0.15 mm to 0.5 mm, and finally sintering treatment is conducted to obtain the rough ceramic coating. According to the method, the bonding firmness of the surface coating of the ceramic material and other materials can be remarkably improved, the possible negative influence of a subtractive roughening process on the mechanical property of the material is effectively avoided, meanwhile, the method does not depend on specific equipment and material growth characteristics, and therefore the method has a wider application prospect.

Representative implementations provide techniques and systems for processing integrated circuit (IC) dies. Dies being prepared for intimate surface bonding (to other dies, to substrates, to another surface, etc.) may be processed with a minimum of handling, to prevent contamination of the surfaces or the edges of the dies. The techniques include processing dies while the dies are on a dicing sheet or other device processing film or surface. Systems include integrated cleaning components arranged to perform multiple cleaning processes simultaneously.

The invention relates to the technical field of oriented strand boards, and discloses a fine-surface oriented strand board and a preparation method thereof.The fine-surface oriented strand board sequentially comprises a surface layer, a core layer and a surface layer, and the fine-surface oriented strand board is prepared by conducting sizing, oriented paving, pre-pressing and hot pressing on wood shaving raw materials of all the layers; wherein the raw material of the surface layer is surface layer fine wood shavings, and the surface layer fine wood shavings are glued through an isocyanate adhesive with the mass fraction of 6% and a urea aldehyde acid ester adhesive with the mass fraction of 8-12%; the raw material of the core layer is core layer large-sheet wood shavings, and the core layer large-sheet wood shavings are glued by an isocyanate adhesive with the mass fraction of 4-6% and a paraffin emulsion with the mass fraction of 0.5-2%. According to the method, the isocyanate adhesive and the urea-formaldehyde resin adhesive are synchronously applied to the surface layer fine shavings, and the paraffin emulsion is only applied to the core layer large shavings, so that the surface bonding strength of the FOSB is higher, meanwhile, the 24-hour TS of the FOSB is lower, and the internal bonding strength and the bending strength can both meet the use requirements.

The invention discloses a preparation method of an all-composite mast, which belongs to the technical field of ships and comprises the following steps: a, preparing a bottom flange; b, preparing a mast main body, and winding an inner skin on the mast main body; c, the bottom flange is assembled to the mast body, and the inner skin is pre-cured; d, the boundary dimension of the inner skin is machined, and the honeycomb core is bonded to the surface of the inner skin; e, stabilizing the honeycomb core, and winding an outer skin on the honeycomb core; f, carrying out integral curing treatment, and carrying out boundary dimension processing and finishing on the cured outer skin; and g, demolding. The bottom flange is prepared and formed by the composite material through the autoclave technology, the bottom flange is inserted into the mast body to be integrally formed, the bottom flange prepared through the technology is light in weight, high in strength, easy to machine and good in connecting performance with the mast body, the strength and stability of the connecting part are improved, and the number and complexity of connecting pieces are reduced.

The utility model belongs to the technical field of seats, and particularly relates to a seat energy absorber using a turnup pipe, which comprises an inner sleeve and an outer sleeve sleeved outside the inner sleeve, an inner sleeve connecting lug and an outer sleeve connecting lug are respectively arranged at the outer ends of the inner sleeve and the outer sleeve, the inner sleeve and the outer sleeve are both made of carbon fiber materials, and the turnup pipe is arranged in the outer sleeve. A layer of stainless steel sleeve is arranged on the outer surface of the inner sleeve, one end or two ends of the stainless steel sleeve is / are provided with a turnup pipe which is formed by firstly flanging outwards and then flanging, and the outer surface of the turnup pipe is connected with the inner surface of the outer sleeve in a bonding mode. The energy absorber has no influence on passengers and the environment, is low in manufacturing, mounting and maintaining cost, light in weight and high in strength, and is suitable for aero seats.

The present application relates to a kind of high-temperature-resistant inductive angle sensor, belong to angle sensor technical field.The sensor includes: gradient composite ceramic substrate Al2O3-ZrO2-Al2O3, realize thermal expansion coefficient gradient matching by intermediate layer zirconium oxide doped yttrium oxide, reduce thermal stress cracking risk;Substrate surface is formed with micro-arc oxidation porous layer in turn titanium nitride nanocrystalline layer, improve surface bonding force;Atomic layer deposition process is used to prepare TiN or TiN / Ag composite film coil, improve temperature resistance;Through electron beam welding and transient liquid phase bonding composite process coil and circuit;Insulating encapsulation layer is made of boron nitride nanosheet and high-temperature-resistant resin, improve thermal conductivity and breakdown field strength.The present application is through gradient substrate design, thin film coil integration and composite process optimization, solves the thermal stress failure of traditional inductive sensor under high temperature, coil oxidation and insulation aging problem, suitable for angle measurement under extreme environment.

The application discloses a kind of X waveband wave-absorbing honeycomb composite layer structures based on graphene derivative, composite material and preparation method and application thereof, method steps include: honeycomb material processing: cutting and washing to honeycomb material;Configuration wave-absorbing slurry: configuration graphene derivative wave-absorbing slurry, and stirring and sanding are carried out;Two times of impregnation: aramid paper honeycomb sheet is impregnated into graphene derivative wave-absorbing slurry, then drying is carried out, and two times of impregnation are carried out;Surface bonding treatment: glass fibre and / or epoxy resin skin are bonded on the upper surface of honeycomb sheet, and conductive carbon fibre and / or epoxy resin skin are bonded on the lower surface of honeycomb sheet.The application can realize the strong absorption (RL<-15dB) characteristics of X waveband electromagnetic wave under thin thickness (8mm), and the material has good structural strength and environmental adaptability, and the preparation method is simple, the cost is moderate, and is suitable for large-scale industrial production.

The utility model relates to the technical field of waterproof coiled materials, and particularly discloses an APF self-adhesion waterproof coiled material which is characterized by comprising a supporting frame, a groove is formed in the upper end of the supporting frame, and a plurality of through holes are formed in the groove in a penetrating mode; a macromolecule sheet is arranged in the groove and connected with the groove in a matched mode, a plurality of self-adhesive layers are correspondingly arranged at the lower end of the groove, and the self-adhesive layers correspond to the through holes in position. The utility model aims to solve the problems of waste of a self-adhesive layer, poor air permeability, high possibility of swelling, high material cost, weak base layer deformation adaptability, high maintenance difficulty and the like caused by full-surface attachment of the self-adhesive layer of the existing waterproof roll.

The present invention discloses a tool for gluing special-shaped complex curved surfaces and a processing method thereof, comprising a tool body for supporting parts and a clamping member for fixing parts; the tool body comprises a plurality of horizontal petals, the plurality of horizontal petals are distributed hierarchically from top to bottom, and two adjacent horizontal petals are fixedly connected; the horizontal petals comprise an arc portion and a straight portion, and the arc portion and the straight portion are fixedly connected. The tool of the present invention is processed in steps, and independent arc portions and straight portions are obtained by CNC milling. The tool body is formed by two assembly processes. When the horizontal petals are assembled to form the tool body, the assembly process of each layer of horizontal petals is carried out on the same reference plane, which can reduce the error of the forming process; the split processing and then welding forming can reduce the processing difficulty of the tool body and save materials at the same time.

The present invention discloses a method for calculating the adsorption performance of water molecules on the surface of rare earth element-doped iron. The method comprises: firstly, constructing a reasonable surface model through software modeling, doping rare earth elements into the surface model, then adsorbing water molecules on the doped surface model, calculating the adsorption energy through first principle calculation, determining the optimal adsorption site of water molecules, and then using molecular dynamics to calculate the changes in the adsorption energy and adsorption site of water molecules with increasing temperature. Finally, electronic performance calculations are used to analyze the transfer of electrons and changes in surface bonding after the adsorption of water molecules. The present invention studies the adsorption of water molecules on the surface of rare earth element-doped iron from a computational perspective, provides a data basis for studying the influence of water molecules adsorbed on metal surfaces on metal properties, and further fundamentally explains the mechanism of corrosion, laying the foundation for solving the corrosion problem of steel materials.

The utility model discloses a waterproof wear -resisting type slipper relates to slipper technical field, including sole, the top surface bonding of sole has vamp, the top surface of sole is equipped with first drain and second drain, the top of sole is equipped with antiskid salient, the both sides of sole are bonded with first wear -resisting piece, the outer wall mounting of first wear -resisting piece has second wear -resisting piece, one side of first wear -resisting piece is equipped with third wear -resisting piece. This waterproof wear -resisting type slipper is provided with first drain and second drain, when the slipper is contacted with ponding, the user lifts the foot, and the water stain can be discharged quickly through first drain and second drain, prevents the water stain to remain, influences the comfort of wearing, and can first wear -resisting piece, second wear -resisting piece and third wear -resisting piece carry out quick positioning installation dismounting, is convenient for maintenance, and through first wear -resisting piece, second wear -resisting piece and third wear -resisting piece can obviously promote the wear -resisting capacity of slipper.

The invention relates to the technical field of oilfield exploitation, and provides a self-healing gel plugging system with high wall surface binding capacity and a using method and application thereof.The plugging system is composed of self-healing gel, a wall surface binding agent and a self-healing inducer, and the wall surface binding agent serves as an intermediate to play a bridge role; a catechol group on one side of the nano-sheet has multiple interaction with active sites on the rock surface, and amino on the other side of the nano-sheet and an aldehyde group of a cross-linking agent form a Schiff base bond, so that a wall surface-nano-sheet-gel bridging structure is constructed, and a gel network is firmly anchored on the rock wall surface. The gel network can be crosslinked again to realize self-healing after being damaged by depending on an amino-aldehyde group dynamic reversible bond; the self-healing inducer gradually releases acidic components under stratum conditions, adjusts local pH, promotes aldehyde group-amino condensation crosslinking and improves the long-term stability of the system. Particle fluid channeling can be effectively inhibited, the water flooding swept volume is improved, and therefore the crude oil recovery rate is increased.

The utility model relates to the technical field of cartons, in particular to a damp-proof and compression-resistant structure of a color box of a color box carton, which comprises a box body, a box cover is sleeved on the top of the box body, a damp-proof and compression-resistant piece is arranged in the box body and comprises four rectangular vertical pipes arranged in a matrix, reinforcing vertical plates are arranged in the rectangular vertical pipes, and rectangular sliding plates are arranged at the bottoms of the reinforcing vertical plates. Drying agents are placed in the rectangular vertical pipes and located on the two sides of the reinforcing vertical plates, a plurality of air holes a are formed in the opposite side faces of the two rectangular vertical pipes which are oppositely arranged in the front-back direction, and a plurality of air holes b are formed in the opposite side faces of the two rectangular vertical pipes which are oppositely arranged in the left-right direction. According to the damp-proof and pressure-resistant structure of the color box of the color box carton, the rubber sealing lining adheres to the side face of the inner wall of the carton cover to form a sealing structure, moisture is prevented from entering the carton body through a gap between the carton cover and the carton body, the damp-proof and pressure-resistant part is arranged in the carton body, structural reinforcement can be conducted on the interior of the carton body, and the pressure-resistant capacity of the carton body is remarkably enhanced.

The steel-plastic grating thermal composite geotextile comprises a non-woven fabric, and a transverse grating belt and a longitudinal grating belt are arranged on one side of the non-woven fabric; the length direction of the transverse grating belts is parallel to the length direction of the non-woven fabric, and the transverse grating belts are arranged in the width direction of the non-woven fabric at intervals. The length direction of the longitudinal grating belts is parallel to the width direction of the non-woven fabric, and the longitudinal grating belts are arranged in the length direction of the non-woven fabric at intervals. Every two adjacent transverse grating belts are located on the two sides, close to and away from the non-woven fabric, of the same longitudinal grating belt correspondingly. The adjacent surfaces of the transverse grating belts, the longitudinal grating belts and the non-woven fabric are bonded. The transverse grating belts and the longitudinal grating belts are arranged in a staggered mode, the strength of the composite geotextile can be effectively improved, the composite geotextile is different from a steel-plastic grating, the barrier effect can be achieved through the non-woven fabric, the problem that holes exist in a pure steel-plastic grating is solved, the structure is convenient to bend, and after the composite geotextile is matched with the non-woven fabric, the overall strength is reasonable, and the service life of the composite geotextile is prolonged. And the loading capacity is higher.

The present invention discloses a method for enhancing the surface bonding strength of ultra-high temperature ceramic coatings through additive roughening, belonging to the technical field of ceramic coating preparation. A bonding layer slurry is disposed on the surface of the ultra-high temperature ceramic coating to obtain a bonding layer, and then a rough layer slurry is disposed on the surface of the bonding layer for roughening to obtain a rough layer. The range of the maximum surface height difference Ry in the rough layer is controlled to be 0.15 - 0.5 mm. Finally, sintering treatment is carried out to obtain a rough ceramic coating, thus achieving the goal. The method of the present invention can not only significantly enhance the bonding firmness between the surface coating of ceramic materials and other materials, but also effectively avoid the possible negative impact of subtractive roughening process on the mechanical properties of materials. At the same time, it does not depend on specific equipment and material growth characteristics, and therefore has a broader application prospect.

The utility model discloses a packaging structure of an integrated circuit, which relates to the technical field of integrated circuit packaging, and comprises a bottom plate and a space groove arranged on the inner surface of the bottom plate, the inner surface of the space groove is provided with a sealing gasket, the upper surface of the bottom plate is bonded with a top cover, the surface of the bottom plate is provided with pins, and the pins are connected with the space groove. The upper surface of the top cover is provided with four pins, the lower surface of each pin is provided with a chamfer, the upper surface of the top cover is provided with four screw holes, the upper surface of the top cover is provided with an aluminum plate, the top cover is made of aluminum, the upper surface of the aluminum plate is fixedly connected with a plurality of fins, and the fins are uniformly distributed on the upper surface of the aluminum plate. Compared with an existing packaging structure of a common integrated circuit, the packaging structure of the integrated circuit has the advantages that the space between the space groove and the top cover is filled with the sealing gasket, the sealing performance of the packaging structure is enhanced, and the surface of the pin is provided with the chamfer, so that the pin can be conveniently inserted in a proper position.

The utility model provides a fine steel wire braided reinforced silicone rubber insulated power cable, which relates to the field of power cables and comprises a silicone rubber cable body, a cable outer structure layer and a conductive wire core are arranged in the silicone rubber cable body, and a shielding layer is arranged at the inner side end of the cable outer structure layer. A reinforcing structure layer is bonded to the outer surface of the shielding layer, a thin steel wire layer is arranged in the middle of the reinforcing structure layer, the inner side face and the outer side face of the thin steel wire layer are wrapped and bonded with a second silica gel cotton layer and a first silica gel cotton layer respectively, and the outer side face of the first silica gel cotton layer is wrapped with a first polyester elastic layer; and the inner side surface of the second silica gel cotton layer is connected with the shielding layer through the second polyester elastic layer. According to the utility model, the problem that in the prior art, when a silicone rubber cable is bent, an internal metal net layer easily generates pressure on a structural layer in contact with a bent surface, so that the structural layer in the silicone rubber cable is abraded or deformed is solved.

The application discloses a two-step plasma treatment method for enhancing the surface bonding performance of polytetrafluoroethylene material, and the treatment method comprises the following steps: (1) adopting a first plasma to perform surface treatment on polytetrafluoroethylene, wherein the discharge gas of the first plasma is argon or a mixed gas containing argon; (2) adopting a second plasma to bombard the surface of the polytetrafluoroethylene material after the surface treatment in step (1), so as to form a carbon-nitrogen cross-linked layer on the surface of the polytetrafluoroethylene, and obtain polytetrafluoroethylene with high bonding performance, wherein the discharge gas of the second plasma is a mixed gas of argon, methane and ammonia. The polytetrafluoroethylene sample treated by the above method has good hydrophilic performance and extremely strong bonding performance, the sample surface always maintains good hydrophilic performance in air for three months without any treatment, and the bonding strength between the treated polytetrafluoroethylene and special glue is as high as 77 N / 10 mm ‑1 .

The utility model relates to the technical field of application, and discloses an improved medical application which comprises an application main body, the lower surface of the application main body is divided into two sticking areas and an anti-sticking spacer mounting area, the anti-sticking spacer mounting area is located between the two sticking areas, a non-woven fabric breathable layer is arranged on the upper surface of the application main body in a sticking mode, and the non-woven fabric breathable layer is arranged on the lower surface of the application main body. First plastic tearing films are bonded to the two bonding areas on the lower surface of the application main body, an anti-bonding isolation piece is bonded to the anti-bonding isolation piece mounting area on the lower surface of the application main body, and side bonding strips are arranged at the left end and the right end of the application main body and the left end and the right end of the non-woven fabric breathable layer. The visible windows are formed in the middle of the application body, the middle of the anti-sticking isolation piece, the middle of the first plastic tearing film and the middle of the non-woven fabric breathable layer, so that nursing personnel can observe whether the puncture part of a patient is red and swollen, errhysis and seepage through the visible windows in the infusion and remaining needle maintenance process, and infusion safety of the remaining needle is guaranteed.

1. The name of this design product: Robotic flexible glue spraying device. 2. Purpose of this product with design: This product with design is used in the automotive field to automatically spray glue on the surface of the product body or the surface bonding surface. 3. The key point of the design of this product lies in its shape. 4. The picture or photo that best illustrates the design points: Stereoscopic drawing 1.

The utility model relates to the technical field of adhesive stickers, in particular to an easy-to-tear adhesive sticker which comprises bottom paper and an anti-deformation mechanism, the anti-deformation mechanism comprises an adhesive sticker layer, a memory support layer, a double-faced adhesive tape layer and an anti-deformation layer, the adhesive sticker layer is fixed to the upper surface of the bottom paper in an adhesive mode, and the memory support layer is fixed to the upper surface of the anti-deformation layer. The lower surface of the memory support layer is fixedly adhered to the upper surface of the non-setting adhesive layer, the lower surface of the double-sided adhesive layer is adhered to the upper surface of the memory support layer, and the lower surface of the anti-deformation layer is fixedly adhered to the upper surface of the double-sided adhesive layer; the anti-deformation layer is arranged, so that the non-setting adhesive sticker is not prone to wrinkling, the memory support layer is arranged, the non-setting adhesive sticker is prevented from being wound, the anti-static layer is arranged, static electricity is prevented from being generated, safety is improved, the easy-to-tear opening is formed in the release paper, and the arc-shaped openings are formed in the two sides of the release paper, so that the non-setting adhesive sticker is easier to tear; and an easy-to-tear handle is arranged on the side surface of the backing paper, so that the backing paper is easy to tear off from the non-setting adhesive layer.

The utility model provides a sand conveying belt scraping mechanism for concrete preparation. The sand conveying belt scraping mechanism comprises a first mounting plate and a second mounting plate which are fixedly connected with the outer wall of the end of a rack of a belt conveyor. Seat sleeves are mounted on the outer walls of the first mounting plate and the second mounting plate in a penetrating manner; rotating rods are mounted in the seat sleeves on the two sides in a running fit manner; a scraping plate in contact with the outer surface of the belt is fixedly mounted in the middle of the rotating rod; the two outer ends of the rotating rod are sleeved with rotating sleeves through locking mechanisms respectively, rotating plates are fixed to the outer walls of the rotating sleeves, and elastic pressing mechanisms for always pressing the scraper blade are fixed between the rotating plates and the first mounting plate and the second mounting plate on the corresponding sides. According to the scraping mechanism, the elastic pressing mechanism is adopted, the rotating plate can be pressed tightly all the time, then rotating torque is generated on the rotating rod, the scraping plate is pressed tightly on the outer surface of the belt all the time through the rotating rod, and therefore materials adhering to the outer surface of the belt are scraped away.

The invention relates to the field of aluminum alloy, in particular to a method for in-situ growth of an environment-friendly ceramic protective coating for an aviation aluminum alloy structural part through micro-arc oxidation and various coatings prepared through the method. Firstly, a micro-arc oxidation ceramic layer is prepared on the surface of an aluminum alloy, then a wave-absorbing coating is compounded on the surface of the oxidation ceramic layer, and the aluminum alloy wave-absorbing functional coating with the corrosion protection performance and the wave-absorbing function is prepared. The ceramic layer with a compact microstructure is prepared, and the corrosion resistance of the aluminum alloy is remarkably improved. The wave-absorbing coating compounding technology has the effect of sealing the porous ceramic layer, the corrosion resistance of the ceramic layer is further improved, meanwhile, the ceramic layer has the wave-absorbing function, and the absorption strength and the absorption peak frequency interval can be effectively changed by adjusting the type, content and electromagnetic parameters of a wave-absorbing agent and the thickness of the coating. The comprehensive coating prepared by the invention has the characteristics of excellent corrosion resistance, firm surface bonding, wide electromagnetic wave absorption frequency band and the like, and can be widely applied to the fields of aviation, aerospace, military industry, electronic products and the like.

The application discloses a metal thin layer structure for surface bonding and a preparation method. The metal thin layer comprises two WTi mixed metal layers and three Au metal layers. The metal thin layer is prepared by a magnetron sputtering process, an electroplating process and the like. Compared with the prior art, the metal thin layer structure is used as an upper plate of a capacitor, has higher adhesion and high bonding tensile strength, and can still maintain excellent performance after experiencing high-strength reliability tests.

The application discloses a kind of porous ultrafine silica powder with core-shell structure and its preparation method, the silica powder includes inner core and the shell of coating on the surface of inner core, the porosity of shell is greater than the porosity of inner core, the ratio of the radius r of inner core and the layer thickness d of shell satisfies 1:0.2~0.6;The silica powder gives consideration to mechanical strength and low dielectric property and high dimensional stability.The preparation method includes: on the basis of conventional silica powder as inner core, by sol-gel method, a layer of amorphous porous silica outer layer is coated, by adding dispersing agent, the agglomeration of particles is inhibited and the sphericity of the obtained porous ultrafine silica powder with core-shell structure is improved, further using the instantaneous high temperature during flash drying makes the surface of particles instantaneous shrinkage, improves the sphericity and surface bonding strength of the porous ultrafine silica powder with core-shell structure, and then the fluidity and mechanical strength of the material are improved.