43results about How to "Barrier contact" patented technology

The invention provides a halide solid-state electrolyte and a preparation method and application thereof. The halide solid-state electrolyte comprises a halide solid-state electrolyte inner core and a halide solid-state electrolyte outer core, and the hydrophobic layer is uniformly coated on the halide solid electrolyte core, and the hydrophobic layer comprises bis-hexadecyl phosphate. According to the halide solid electrolyte as well as the preparation method and the application thereof, the air stability of the halide solid electrolyte can be remarkably improved, the cycle performance of an all-solid-state lithium ion battery is improved, the manufacturing process is simple, and the cost is relatively low.

The invention relates to the field of dental care, in particular to a tooth polishing agent with an antibacterial effect and a preparation method thereof, and the tooth polishing agent is prepared from the following raw materials: silicon dioxide, sodium carboxymethyl cellulose, xanthan gum, propylene glycol, cocamidopropyl betaine, glycerol, modified nano-zinc oxide, modified nano-hydroxyapatite, glucolactone, stevioside and sodium benzoate. The modified nano-zinc oxide, the modified nano-hydroxyapatite and the glucolactone play a role through a synergistic effect, the modified nano-hydroxyapatite is used as a carrier to adsorb chemical substances such as the modified nano-zinc oxide and the like to form rod-shaped nano microcapsules, and a compact and uniform protective layer is formed on the tooth surface through a nano-size effect; the glucolactone promotes slow release of the rod-shaped nano microcapsules, and the glucolactone, the rod-shaped nano microcapsules and the glucolactone form a dynamic balance system, so that the antibacterial and remineralization effects are continuously exerted, the tooth structure is strengthened, the pH value is adjusted, the oral environment is maintained, and comprehensive and long-acting protection is provided for oral health.

This invention belongs to the technical field of aluminum powder passivating agents, specifically relating to an aluminum powder passivating agent and its preparation method. The preparation method of the aluminum powder passivating agent includes the following steps: heating a solvent, adding anchoring functional monomers, including styrene-based phosphoric acid, hydroxyethyl methacrylate phosphate, and 2-methacryloyloxyethyl phosphate, stirring until homogeneous, continuing to add mixed monomers, stirring until homogeneous, adding a mixed solution of initiator and solvent dropwise, allowing the reaction to complete, adding solvent to adjust the solid content after the reaction, cooling to room temperature, and obtaining the aluminum powder passivating agent. This invention provides a novel aluminum powder passivating agent and its preparation method. This passivating agent forms a stable protective layer through surface passivation, effectively blocking the contact between aluminum powder and water, inhibiting hydrogen generation, avoiding can bulging, and exhibiting high stability.

The application discloses an antioxidant composite ceramic aerogel and a preparation method thereof, and belongs to the technical field of composite ceramic aerogels.The main body of the antioxidant composite ceramic aerogel is a silicon nitride aerogel, the nanostructure of the silicon nitride aerogel is one of one-dimensional silicon nitride nanowires and two-dimensional silicon nitride nanobands or a combination of the two nanostructures, and a mullite coating and a copper-nickel metal coating are sequentially coated on the nanostructure of the silicon nitride aerogel from inside to outside.The application can solve the technical problem that the prior art cannot prepare silicon nitride ceramic aerogels which can stably serve in a high-temperature oxygen environment at low cost and in batches.

A spreader based on a self-propelled quantitative feeding system comprises a conveying auger, a conveying hopper and a connecting box, the conveying auger used for conveying materials is arranged in the conveying hopper, the discharging end of the conveying hopper is perpendicularly communicated with the vertical connecting box, and the lower end of the connecting box is communicated with the upper end of a funnel-shaped blanking cone; a plurality of scattering plates distributed in the center are arranged at the opening position of the lower end of the blanking cone, a center connecting shaft driving all the scattering plates to rotate penetrates through the blanking cone and the connecting box and is in transmission connection with a driving motor arranged at the top of the connecting box, and the conveying auger is driven by a driving motor at the other end to rotate. The device has the functions of scattering and feeding at the same time, the scattering function is used in the growing period, the feeding function is used in other growing periods, and manual fodder carrying and manual feeding are avoided.

The invention discloses an insulator fixture with a locking structure. A clamping piece is located below a fastening boss and arranged on an insulating spacer through a fastening bolt; a connecting thread and a positioning thread are arranged on the rod portion of the locking bolt, an internal thread matched with the connecting thread is arranged in the connecting section of the locking through hole, the positioning thread extends into the locking cylinder to be connected with the internal thread, a guide protruding strip is arranged on the outer wall of the locking cylinder, and a guide groove is formed in the inner wall of the locking through hole in the axial direction of the locking through hole. And the locking cylinder is provided with a wedge-shaped groove clamped at the thread of the fastening bolt, and the wedge-shaped groove forms locking. The fastening bolt is rotated to enable the clamping piece to make close contact with the cable and fix the cable on the fastening boss below the fastening boss of the insulating spacer, when the locking bolt rotates, the guide protruding strip drives the locking cylinder to move horizontally under the action of the guide groove, and finally the wedge-shaped groove of the locking cylinder is clamped at the thread of the fastening bolt to be locked. Accurate control and firm locking of the position of the clamping piece are achieved.

The invention discloses a tin-zinc-copper powder ultrafine powder batch preparation process, and relates to the technical field of metal powder preparation, and the tin-zinc-copper powder ultrafine powder batch preparation process comprises the following steps: dissolving tin salt, zinc salt and copper salt in deionized water, adding a complexing agent, and uniformly mixing to obtain a mixed metal salt aqueous solution; dissolving a rosin-based polyamine hyperbranched dispersant in an organic solvent to serve as an oil phase; slowly adding a mixed metal salt aqueous solution into the oil phase, and uniformly dispersing to obtain a water-in-oil microemulsion system; dropwise adding a reducing agent solution, and continuously carrying out heat preservation reaction for 0.5-3 hours after dropwise adding is finished, so as to obtain slurry containing alloy particles; and carrying out demulsification treatment, centrifugal separation, repeated washing and drying to obtain the surface-modified tin-zinc-copper superfine powder. Superfining of particles is achieved through confinement growth, synchronous co-deposition of multi-component elements is guaranteed, a homogeneous alloy phase is formed, component segregation is avoided, and a protective layer formed on the surface of the powder in situ endows the material with excellent oxidation resistance and good weld-aid wettability.

This invention discloses a low-corrosion chloride molten salt heat transfer and storage medium, method, and application, belonging to the field of molten salt thermal storage technology. The high-heat-capacity, low-corrosion carbonate molten salt heat transfer and storage medium of this invention is composed of 18%~22% potassium chloride, 6%~10% sodium chloride, 1%~3% aluminum powder, 1%~3% magnesium powder, 1%~3% zinc powder, with the remainder being zinc chloride. Its key feature is the introduction of metal powder into the molten salt, which not only achieves excellent thermal storage performance at 600℃~800℃, but also reduces corrosion by utilizing the potential regulation ability of dissolved metal ions and the formation of highly active [Al] from gaseous chloride products through physical and chemical adsorption. This low-corrosion chloride molten salt heat transfer and storage medium achieves excellent thermal storage performance and low corrosivity, and can be applied in solar thermal power generation and molten salt energy storage.

The present invention provides a special optoelectronic composite cable for use in extremely cold weather, belonging to the technical field of optoelectronic composite cable preparation; it comprises a cable core, a water-blocking layer, a cold-resistant reinforcement layer, and a cold-resistant sheath layer. The present invention effectively prevents moisture intrusion through the water-blocking layer, the cold-resistant reinforcement layer provides additional mechanical strength, and the cold-resistant sheath layer fully protects the internal structure of the optoelectronic composite cable. This multi-level and multi-functional structural design enables the optoelectronic composite cable in extremely cold weather to better meet the complex use requirements in extremely cold environments, and provides a reliable solution for communications and energy transmission in cold areas.

This invention discloses a chromium-free passivation and fingerprint-resistant composite treatment method for high-aluminum-zinc-aluminum-magnesium steel plates, belonging to the field of metal sheet surface protection technology. The specific steps of the method are as follows: A fine-grained high-aluminum-zinc-aluminum-magnesium steel plate is selected as the substrate, and firstly, it undergoes multi-stage cleaning and hot air drying. Next, the dried substrate is immersed in a composite chromium-free passivation solution to form a passivation precursor film. Then, a porous inorganic passivation layer is prepared through low-temperature hot air curing. Subsequently, a modified fingerprint-resistant resin is roller-coated onto its surface to form an organic precursor film. Finally, a constant-temperature curing treatment is performed to produce a chromium-free passivation and fingerprint-resistant composite film. This invention uses multi-stage cleaning and chromium-free passivation processes on the high-aluminum-zinc-aluminum-magnesium steel plate to form a porous inorganic passivation layer, enhancing corrosion resistance. Then, a composite protective film layer is constructed by reverse roller coating of modified fingerprint-resistant resin, achieving functional integration. This process improves the environmental protection and protective properties of the plate, meets the needs of multiple fields, and expands the application scenarios and market scope.

The invention relates to the technical field of aluminum electrolysis metallurgy, in particular to an aluminum electrolysis carbon anode anti-oxidation coating and a preparation method thereof. The coating is prepared from the following raw materials in percentage by mass: 45-60% of aluminum oxide powder; 15 to 25% of water glass; 8-12% of potassium feldspar powder; 0.5 to 2% of sodium fluoride; 7-11% of sodium acetate trihydrate; 8-12% of ionized water; the preparation method comprises the following steps: S1, preparing the catalytic compact component; s2, mixing the coating; s3, coating and drying; and S4, carrying out high-temperature calcination. The product provided by the invention has good oxidation resistance, adhesive force and compactness, and the preparation method provided by the invention has the advantages of simple process and low cost.

This application relates to a passivation treatment solution, aluminum alloy components, and a method for preparing the same. The passivation treatment solution comprises a solvent and components dispersed in the solvent at the following concentrations: fluorozirconate 5 g / L–30 g / L, fluorinated silane coupling agent 10 ml / L–50 ml / L, polyphenol complexing agent 1 g / L–8 g / L, and silicate 5 g / L–25 g / L. The passivation treatment solution, through a multi-component synergistic formulation composed of fluorozirconate, fluorinated silane coupling agent, polyphenol complexing agent, and silicate, exhibits different functions and molecular bridging synergistic effects. After passivation treatment of anodized aluminum alloys, the alkaline corrosion resistance of the aluminum alloys can be significantly enhanced.

The application discloses an electrolyte and a battery. The electrolyte comprises an electrolyte, a solvent, a first additive and a second additive. The first additive is selected from at least one of structural formula (1) to structural formula (4), and the second additive is selected from at least one of structural formula (5) to structural formula (7). The first additive has high oxidation resistance, and contains an unsaturated double bond which can be polymerized to form an SEI protective film on a negative electrode. The protective film inhibits the volume expansion of the silicon negative electrode. The second additive can form a polymer film on the surface of a positive electrode under high voltage, which can improve the oxidation resistance of the electrolyte. Through the joint action of the first additive and the second additive, a stable film layer is formed on the surface of the electrode, the volume expansion of the electrode is inhibited, the interface on the surface of the electrode is prevented from being damaged by expansion stress, the contact between the electrolyte and the electrode material is blocked, the oxidation resistance of the electrolyte is improved, the performance stability of the battery under high voltage is improved, and the high-temperature storage and cycle performance of the battery are improved.

This invention relates to the fields of fine chemicals and polymer materials technology, specifically a method for manufacturing toy adhesives. It includes steps for preparing the adhesive base material, preparing borax solution, and cross-linking molding. Polyvinyl alcohol, guar gum, methylparaben, etc., are prepared as base materials, which are then reacted with borax solution to undergo a cross-linking reaction. The core of this invention is the strict limitation of specific high-temperature ranges and constant-temperature stirring times during the base material preparation process, which promotes the complete extension and entanglement of molecular chains, constructing a dense and uniform three-dimensional network structure. This invention effectively avoids microscopic particle residue and stress concentration, achieving a significant improvement in the tensile strength, elongation at break, and resilience of the toy adhesive.

The invention relates to the technical field of functional films, and discloses a flame-retardant scratch-resistant ultraviolet-resistant colorful film and a preparation method thereof.The colorful film comprises a colorful layer, a flame-retardant layer and an ultraviolet-resistant scratch-resistant protective layer, the colorful layer, the flame-retardant layer and the ultraviolet-resistant scratch-resistant protective layer are of a DC-... ABA...-CD structure, the D layer is the ultraviolet-resistant scratch-resistant protective layer, and the D layer is the ultraviolet-resistant scratch-resistant protective layer. The C layer is a flame-retardant layer, and the middle layer is a colorful layer; the colorful layer is made of materials with different refractive indexes, the materials are arranged alternately according to the arrangement mode of ABA and the like, the layer A is made of polyethylene glycol terephthalate, and the layer B is made of polymethyl methacrylate; according to the preparation method, raw materials of the layer A and the layer B are prepared, and then the colorful layer is prepared in an alternate arrangement mode; then extruding the anti-ultraviolet and anti-scratch protective layer, coating one side, connected with the colorful layer, of the extruded anti-ultraviolet and anti-scratch protective layer with a flame-retardant material to form a flame-retardant layer, and finally performing hot pressing on the anti-ultraviolet and anti-scratch protective layer and the colorful layer to form the required colorful film.

The present invention relates to the field of battery material technology, and specifically to a composite positive electrode material, a preparation method and application thereof. The composite positive electrode material is a core-shell structure, including a core and a coating layer coated on the surface of the core; wherein the core is a carbon-coated lithium iron manganese phosphate-doped lithium-rich manganese-based material; and the coating layer is lithium iron manganese phosphate. The composite positive electrode material provided by the present invention not only greatly improves the discharge specific capacity and cycle stability of the lithium-rich manganese-based material, but also effectively blocks the contact between the lithium-rich manganese-based material and the electrolyte, greatly improving the safety performance of the positive electrode material system. The technical solution of the present invention effectively solves the problems in the prior art that the lithium-rich manganese-based material catalyzes the decomposition of the electrolyte, causing rapid attenuation of battery performance, potential safety hazards, and the improved composite lithium-rich manganese-based material has a complex structure, a long process and high cost.

The invention discloses an underwater super-oleophobic polyvinylidene fluoride porous membrane with oil stain adhesion resistance and a preparation method of the underwater super-oleophobic polyvinylidene fluoride porous membrane, and belongs to the technical field of material preparation. Aiming at the problem that the performance of the existing underwater super-oleophobic material is reduced due to the fact that the existing underwater super-oleophobic material is easily adhered and blocked by oil stains, the material is obtained by sequentially constructing a polyvinyl alcohol / tannic acid-polyethyleneimine hydrophilic layer and an amino-modified flexible molecular brush grafting layer on the surface of a polyvinylidene fluoride porous membrane. According to the composite structure, the membrane has underwater super-oleophobicity and dynamic oil stain adhesion resistance, oil drops can be effectively prevented from being attached and accumulated on the surface of the membrane, the anti-pollution performance of the membrane in the oil-water separation process is remarkably improved, and the service life of the membrane in the oil-water separation process is remarkably prolonged. The membrane can efficiently and continuously separate the oil-in-water emulsion with the stable surfactant under the assistance of vacuum, the process is simple, and the membrane has a good practical application prospect.

The present invention relates to the technical field of anticorrosive coatings, and in particular to an anticorrosive coating for oil well pipes and a preparation method thereof, comprising the following raw materials in parts by mass: 40-50 parts of phenolic epoxy resin, 10-15 parts of modified graphene, 1-5 parts of aliphatic amine curing agent, 5-10 parts of reactive diluent, and 5-10 parts of organic solvent; the preparation method of the modified graphene comprises the following steps: A1: preparing a Schif base complex by reacting 3,5-diaminopyrazole and salicylaldehyde; A2: preparing an isocyanate graphene suspension; A3: adding 1H,1H-heptafluorobutylamine and Schif base complex to the obtained isocyanate graphene suspension, stirring and reacting at 30-50°C for 3-5h, filtering, washing, and drying to obtain a modified intermediate; A4: reacting glycidol with the modified intermediate. The anticorrosive coating prepared by the present invention has high bonding strength with oil well pipes, and effectively blocks the contact between corrosive media and metal oil well pipes.

This invention discloses a process for preparing freeze-dried Cistanche deserticola powder with anti-oxidation properties, belonging to the field of traditional Chinese medicine technology. The preparation process is as follows: Fresh Cistanche deserticola is cleaned and impurities are removed, surface moisture is drained, and it is sliced ​​into thin slices. The slices are then immersed in a container filled with purified water. The soaking system and container are pre-frozen together. The pre-frozen whole slices are then freeze-dried and pulverized to obtain freeze-dried Cistanche deserticola powder. This invention effectively avoids the oxidation reaction of Cistanche deserticola during drying, increasing the content of phenylethanoid glycosides. Simultaneously, the freeze-dried Cistanche deserticola powder prepared by this invention can remain unoxidized for a long time in air at room temperature and humidity below 40%, maintaining a snow-white to yellowish-white color, significantly enhancing the product's storage stability and commercial appearance quality.

The invention provides a surface treatment method of a stainless steel water tank and the stainless steel water tank. The stainless steel water tank comprises a base material layer, and a sand blasting layer, a composite chromium carbide coating, a corrosion-resistant layer and a wear-resistant layer are sequentially arranged on the surface of the base material layer; the composite chromium carbide coating at least comprises four layers. Through the varnish coating with a multi-layer structure, the wear resistance and the corrosion resistance of the stainless steel water tank are remarkably improved, and even if the varnish on the outer layer is damaged, the middle layer can still effectively protect the base material from being corroded, so that the service life of the water tank is prolonged; meanwhile, the bottom composite chromium carbide coating improves the wear resistance of the stainless steel water tank and enriches the appearance of the stainless steel water tank. Due to the design of the multi-layer coating structure, the functions of all the layers are complementary, and the overall performance of the water tank is greatly improved.

The invention discloses a wall-crossing tower crane mounting structure and a construction method thereof.The construction method of the wall-crossing tower crane mounting structure comprises the steps that two vertical frame bodies are provided, a plurality of wall penetrating sleeves with the length equal to the thickness of a to-be-spanned wall are provided, and a plurality of half transverse rods arranged in the height direction of the vertical frame bodies at intervals are fixedly mounted on each vertical frame body; the half transverse rods on the two vertical frame bodies are made to be opposite in pairs to form a plurality of pairs of half transverse rods, and the two half transverse rods in each pair of half transverse rods are detachably connected in a butt joint mode to form a plurality of first transverse rods; according to the non-standard transition joint of the tower crane, the problem of cross-wall arrangement of the tower crane in a narrow and small space is solved, the cost of later plate repairing and large-scale machine dismantling is avoided, the cost is saved, the arrangement flexibility of the tower crane is improved, and the construction period is shortened. And the dismantling safety risk is reduced, the construction efficiency is improved, and the high popularization value is achieved.

This utility model relates to a printer, comprising: a frame; a printer core including a support assembly, a printhead assembly, and a roller assembly, wherein the support assembly is movably mounted on the frame, the printhead assembly is connected to the support assembly, and the roller assembly is disposed opposite to the printhead assembly; a paper feed motor mounted on the frame; a cutter assembly including a fixed bracket positioned above the frame; a contact spring located between the fixed bracket and the frame, the contact spring including a base plate and a support leg, the base plate being disposed on the outer bottom wall of the fixed bracket, and the support leg being connected to the housing of the paper feed motor and the support assembly; and a wire, the first end of which is connected to at least one of the support assembly, the housing of the paper feed motor, the fixed bracket, and the contact spring, and the second end being used for grounding; the housing of the paper feed motor, the support assembly, the fixed bracket, and the contact spring are all made of conductive materials. This device can discharge static electricity generated by the paper feed motor, the printer core, and the cutter assembly through a single contact spring, making assembly and disassembly convenient.

This invention relates to the field of marine fouling protection and bactericidal materials, and particularly to a quaternary ammonium salt / copper pyridinethione / montmorillonite composite antibacterial material, its preparation method, and its application. The quaternary ammonium salt / copper pyridinethione / montmorillonite composite antibacterial material uses montmorillonite as a carrier, with quaternary ammonium salt and copper pyridinethione intercalated between the montmorillonite layers. The preparation method involves obtaining copper-loaded montmorillonite through ion exchange, and then introducing pyridinethione anions and quaternary ammonium salt into the copper-loaded montmorillonite to obtain the quaternary ammonium salt / copper pyridinethione / montmorillonite composite antibacterial material. This material exhibits good adsorption performance, high stability, and durability, maintaining its antimicrobial effect for a long time, reducing the frequency and cost of antiseptic treatment, and has broad application prospects.

The invention relates to the technical field of alloy aluminum ingots, and discloses a preparation method of an alloy aluminum ingot containing a nanometer material, the preparation method comprises the following steps: adding an aluminum ingot into a smelting furnace, heating, and slagging off after the aluminum ingot is completely smelted to obtain an intermediate 1; adding copper, manganese, silicon, nano aluminum oxide and iron into the smelting furnace filled with the intermediate 1, and completely melting to obtain an intermediate 2; adding the intermediate 2 into a cavity of a casting grinding tool, and casting to obtain an intermediate 3; the intermediate 3 is put into an annealing furnace to be annealed and then put into a corrosion inhibitor to be soaked, and an alloy aluminum ingot containing the nanometer material is obtained after soaking is finished; after annealing is finished, a corrosion inhibitor is used for treating the aluminum alloy ingot, imidazole, quaternary ammonium salt and nanometer aluminum oxide contained in the corrosion inhibitor have a corrosion inhibition effect, a compact oxidation film can be formed on the surface of the aluminum alloy ingot, contact of corrosive media such as moisture and oxygen is blocked, and the synergistic effect plays a role in corrosion inhibition on the aluminum alloy ingot; and the hardness of the aluminum alloy ingot can be improved by the contained nano aluminum oxide.

The utility model discloses a lifting mechanism of a bar code scanner, and relates to the technical field of bar code scanners. Comprising a bottom plate and a lifting mechanism, the lifting mechanism is arranged on one side of the top of the bottom plate, a motor is arranged on the top of the lifting mechanism, a protective shell is arranged on one side of the lifting mechanism, a controller body is movably arranged in the protective shell, and a transparent movable door is connected to the front face of the protective shell through hinges; and a supporting seat is movably arranged at the bottom of the controller main body. By arranging the protective shell, an independent space can be provided for the controller main body, external personnel or objects can be prevented from accidentally colliding with the controller main body, a certain anti-collision effect is achieved, external pollutants can be prevented from being in contact with the surface of the controller main body, and a certain anti-pollution effect is achieved; these measures help to reduce adverse effects on the controller body, thereby helping to extend its service life.

The application relates to a vacuum rapid-congealing continuous furnace safety door which comprises a door frame arranged at the bottom of a continuous furnace, a maintenance opening arranged at the bottom of the continuous furnace and located in the door frame, a rectangular frame arranged at the front end of the door frame, a door body hinged to one side of the door frame, a plurality of pressing devices arranged on the rectangular frame and used for pressing the door body on the rectangular frame, and an observation window arranged on the door body. The safety door structure provides a preset rapid channel for the bottom of the furnace body. When extreme working conditions such as molten crucible liquid leakage or cooling system water leakage occur, the bottom safety door can be quickly opened to drain water.

The invention relates to the technical field of distribution boxes, and discloses a distribution box with an insulation function, which comprises a box body, the outer surface of the box body is fixedly connected with a driving device, the inner surface of the driving device is in transmission connection with a bidirectional screw rod, and the outer surface of the bidirectional screw rod is movably connected with a push block. The rear side face of the inner wall of the box body is fixedly connected with an inductor, and the two side faces of the inner wall of the box body are fixedly connected with sliding rails. The first insulating plate and the second insulating plate are combined to block the heat dissipation grooves, so that the box body is sealed, and dust in the box body is prevented from floating out of the box body after adsorbing charges; and dust adsorbed with charges is easy to generate static electricity after being accumulated, if flammable and explosive articles exist around, potential safety hazards exist, a sliding shaft bounces and is inserted into a through hole to limit a clamping plate, the first insulating plate and the second insulating plate are attached more stably, the sealing performance is improved, and then the anti-creeping effect is improved.

The utility model relates to the technical field of nitrogen protection equipment, in particular to a simple and convenient coupling agent nitrogen protection device which comprises a raw material barrel, a threaded sealing cover and a protection assembly, the protection assembly comprises a gas inlet pipeline, a discharging pipeline, a control component and an auxiliary component, and the gas inlet pipeline is detachably connected with the threaded sealing cover; in the process of using the raw material barrel, nitrogen is added into the raw material barrel through the gas inlet pipeline, and the pressure of the nitrogen in the raw material barrel is adjusted through the control component, so that the pressure is slightly higher than the atmospheric pressure; the pressure difference is used as power for discharging, so that the coupling agent is discharged outwards through the discharging pipeline, the phenomenon that the barrel cover needs to be frequently opened and closed in the using process to prevent the coupling agent from reacting with air is avoided, contact between the air and the coupling agent is blocked, and the coupling agent is protected.

This invention provides a single-cavity explosion-proof electromagnetic relay, comprising a base plate, a coil support on one side of the base plate, a coil mounted in the coil support, an adsorption plate above the coil support for contacting normally open or normally closed contacts, normally open, normally closed, and other contacts integrated into the base plate, a contact heat-conducting plate embedded within the base plate for contacting the normally open or normally closed contacts, and the upper and lower ends of the coil respectively contacting the coil heat-conducting plate; an inner sleeve connected to the base plate is provided outside the coil support, an outer sleeve is provided outside the inner sleeve, and a support grid is provided inside the outer sleeve, forming a gap between the inner sleeve and the outer sleeve for resin casting; heat dissipation fins are bolted to the outside of the movable cover. This invention maintains excellent explosion-proof performance while ensuring heat dissipation performance, achieving a balance between the two and meeting the requirements for use in a single explosion-proof cavity.

The application discloses a lead-free composite solder and a preparation method thereof. The lead-free composite solder comprises an alloy core and a surface modification layer, and the surface modification layer is coated on the surface of the alloy core. According to mass percentage, the alloy core comprises Ag 0.3%-4.5%, Cu 0.2%-0.8%, Bi 0.5%-3.0%, Sb 0.01%-3.2%, Ni 0.01%-0.2%, Ga 0.005%-0.15%, Ce 0.005%-0.08%, and the rest is Sn. The surface modification layer comprises tin dialkyldithiophosphate and cerium alkylsalicylate. The bimetallic chelate type surface modification layer formed by tin dialkyldithiophosphate and cerium alkylsalicylate is adopted, the interface bonding strength is further strengthened, the solder surface oxidation is effectively inhibited, and the storage stability and environmental adaptability of the solder are improved. The alloy core is prepared through the synergistic matching of multiple components, the excessive growth of interface intermetallic compounds and the grain coarsening are inhibited, and the thermal fatigue resistance and long-term service reliability of the solder joint are improved.