45results about How to "Solve Oxidation Problems" patented technology

The invention relates to the technical field of circuit substrate manufacturing, and particularly discloses a preparation method of a composite solder sheet and an AMB ceramic copper-clad plate. The composite solder sheet is composed of an active metal foil and a copper-containing layer modified on the surface of the active metal foil, and the preparation method of the copper-clad plate comprises the following steps: after the surface of the active metal foil is pretreated, the copper-containing layer is deposited to prepare the composite solder sheet, and the composite solder sheet is placed between a copper substrate and a ceramic sheet to be pressed and assembled. And performing vacuum brazing on the assembly to complete the preparation of the ceramic copper-clad plate. A composite solder sheet containing active metal is adopted, high-temperature element diffusion during vacuum brazing is utilized at the diffusion temperature to achieve alloying of a composite solder layer, and then heat preservation is conducted at the brazing temperature to achieve uniform melting of solder and wetting metallurgical reaction between the solder and copper and between the solder and a ceramic substrate. By means of the preparation method, low-cost and high-reliability preparation of the AMB ceramic copper-clad plate can be achieved, and the prepared AMB ceramic copper-clad plate also has high peel strength and lower weld porosity.

The invention belongs to the technical field of welding, and discloses a dissimilar metal power modulation galvanometer laser welding method which comprises the following steps: finely cleaning a 6061 aluminum alloy and a 304 stainless steel plate by using acetone, and then airing for more than 20 minutes; the aluminum steel sheet is assembled, pressed and fixed on a welding test platform in a steel-up-aluminum-down mode; the position of the welding test platform is adjusted, argon serves as welding protection gas, and a protection gas nozzle is arranged to be aligned with a welding pool area; laser welding parameters are set, a laser power modulation mode is set to be a gradient power mode, and the gradient power mode is to regulate and control phase point laser power in a circular scanning track in the advancing direction of a welding seam; a welding test is carried out in the mode that a galvanometer laser head is fixed and a welding test platform is moved, and a laser and the welding test platform are synchronously started and stopped; and the protective gas is started 5 seconds before the laser is started, and after the laser is stopped, the protective gas is stopped lagging for 10 seconds so as to continuously protect the welding seam and prevent oxidation.

The invention discloses a two-dimensional layered MXene nanosheet and a preparation method thereof, and belongs to the technical field of MXene preparation. The method comprises the following steps: (1) etching an MAX phase powder material by using hydrofluoric acid to obtain an etched MAX phase; (2) centrifuging and drying the etched MAX phase to obtain multi-layer MXene powder; (3) carrying out homogenization treatment on the multiple layers of MXene powder; and (4) carrying out rapid annealing treatment on the powder obtained after homogenization treatment to remove functional groups on the surface of MXene so as to prepare the MXene nanosheet with a regular structure and few defects. The method effectively avoids the oxidation problem of MXene, realizes feasible preparation with uniform thickness, stability, regular shape and fewer defects, and has the advantage of replacing an organic reagent intercalation preparation method to become a mainstream preparation method.

The invention discloses a laser welding method for a large-size ultrathin diaphragm assembly. The laser welding method comprises the steps that the butt joint portion of a diaphragm support and a diaphragm is cleaned; mounting the diaphragm bracket and the diaphragm on a welding positioning tool; the welding positioning tool is clamped to an external laser welding machine rotary table, a welding seam is aligned, laser positioning welding is conducted, and whole-circle positioning welding of the diaphragm support and the diaphragm is completed; and a positioning pressing plate in the welding positioning tool is replaced with a welding pressing plate, laser welding is conducted on the diaphragm and the diaphragm support, and the diaphragm assembly is obtained. By means of the method, efficient and high-quality welding of the large-size ultra-thin diaphragm can be achieved, the welding qualification rate of the diaphragm assembly is increased, the problems that when the large-size ultra-thin diaphragm is welded at present, weld gaps, weld beading, weld joint sinking, wave weld joints and the like are prone to occurring are effectively solved, and the purpose that the product qualification rate is increased to 95% from 30% is achieved.

The invention discloses a preparation method of sphere-like superfine copper powder. The preparation method comprises the following construction steps that raw materials are subjected to extraction, replacement, primary centrifugal separation, primary reduction, secondary centrifugal separation, secondary reduction, tertiary centrifugal separation, antioxidant coating and drying operation, and then the sphere-like superfine copper powder is finally obtained. The method solves the problems of large powder particle size and easy introduction of impurities in various existing superfine copper powder processing technologies, or the problems of expensive equipment, high cost, low yield and easy oxidation of prepared copper powder in preparation. According to the method, the traditional copper powder preparation process is improved, the reaction system is simplified, the reaction is more stable and controllable, the cuprous oxide and the copper are prepared by sequentially reducing the bivalent copper salt, the reaction protective gas is added in the secondary reduction, and the antioxidant is added, so that the prepared superfine copper powder is prevented from being oxidized in the air.

The invention belongs to the technical field of coal mines, discloses a method and a system for determining key pressure injection parameters of liquid CO2 for preventing oxidation of residual coal in a goaf, and aims at taking a coal mine as a research object, and obtaining comprehensive basic data by measuring the inclination length and mining height of a working face and the air distribution amount of the working face in detail. Meanwhile, the oxygen concentrations of different burial depths of the air inlet side of the working face in the test area are measured, and the pressure injection amount of the liquid CO2 and the inhibition effect of the liquid CO2 on coal seam oxidation can be analyzed more accurately in combination with oxygen concentration distribution in the actual coal mine environment. By analyzing the pressure injection period of the liquid CO2, the oxidation reaction of the residual coal is effectively controlled on the premise of not influencing the normal coal mine production. The method not only can be used for fire extinguishing and oxidation control under emergency conditions, but also can use a liquid CO2 injection technology as a daily prevention and control measure, so that the efficiency of coal mine safety production is improved, the risk of fire caused by oxidation is reduced, and the method has a wide industrial application prospect.

The invention belongs to the field of preparation of brazing filler metal, and particularly relates to a preparation method of brazing filler metal. The preparation method of the brazing filler metal comprises the following steps that the upper brazing filler metal strip, the at least one middle brazing filler metal strip and the lower brazing filler metal strip are welded together under the action of an electrode roller; the components of at least one middle brazing filler metal belt are different from those of the upper brazing filler metal belt and the lower brazing filler metal belt, and the upper brazing filler metal belt, the at least one middle brazing filler metal belt and the lower brazing filler metal belt are fused into the whole alloy brazing filler metal during brazing. According to the preparation method of the brazing filler metal, after the multiple brazing filler metal strips enter the electrode roller, the composite interfaces of every two adjacent brazing filler metal strips are melted under the action of resistance heat and form metallurgical bonding under the pressure of the electrode roller, and the functional composite brazing filler metal with extremely high integrity is obtained; on the basis of metallurgical bonding, the brazing filler metal can be conveniently fused into an integral alloy, the deviation design or instability condition of brazing filler metal composition is reduced, and it is guaranteed that the expected welding seam function is achieved.

The invention belongs to the technical field of hot dip coating, and relates to an alloyed powder spraying system and a zinc-aluminum-magnesium coating process based on the alloyed powder spraying system.The alloyed powder spraying system comprises the following steps that 1, alloyed powder is dried for standby application, when the alloyed powder is prepared, high-magnesium-content zinc-aluminum-magnesium alloy is molten in a zinc-aluminum-magnesium pot to form hot dip molten liquid, and the hot dip molten liquid is cooled to the room temperature; the hot-dip coating is waited for use during hot-dip coating; 2, the strip steel is fed into a zinc-aluminum-magnesium pot to be subjected to hot dipping, so that a high-magnesium-content zinc-aluminum-magnesium coating is formed on the surface of the strip steel, and air knife treatment is conducted; and 3, the standby alloy powder in the step 1 is adopted as a cooling agent, alloy powder spraying is conducted on the surfaces of the two sides of the strip steel subjected to hot dipping at the same time through an alloy powder spraying system, a high-magnesium-content zinc-aluminum-magnesium coating is cooled and serves as a nucleation for solidification of a zinc-aluminum-magnesium coating alloy, and the high-magnesium-content zinc-aluminum-magnesium coating alloy is obtained. And cooling control over the solidification process of the high-magnesium-content zinc-aluminum-magnesium coating is achieved by adjusting parameters of the alloy powder.

The invention provides a method for improving the nutrition retention capability of an aqueous solution product, which comprises the following steps: carrying out nitrogen filling treatment on an aqueous solution before ultrahigh-temperature instant sterilization, then carrying out ultrahigh-temperature instant sterilization, and then filling. The method provided by the invention can significantly improve the nutrient retention rate, flavor stability and shelf life of the water aqua product. Experimental data show that the water aqua product prepared by the method disclosed by the invention shows excellent effects in the aspects of nutrient component retention, flavor stability and shelf life, and has a wide application prospect.

This invention discloses a single-component moisture-curing conductive and thermally conductive adhesive and its preparation process, comprising the following raw materials in parts by weight: 100 parts SMP adhesive; 15-30 parts flake silver powder; 500-900 parts spherical silver-coated copper powder; 0-400 parts dendritic silver-coated copper powder; 10-20 parts decamethyltetrasiloxane; 1-1.5 parts β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate isooctyl ester; 7.5-10 parts N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane; and 1-1.5 parts vinyltrimethoxysilane. This invention allows the adhesive to cure at room temperature / low temperature using moisture in the air, eliminating the need for temperatures above 120°C. This completely avoids thermal stress damage to heat-sensitive substrates such as plastics, flexible circuit boards, and PET / PI films, making it perfectly suited for low-temperature processing scenarios such as flexible electronics manufacturing, wearable devices, and flexible sensors.

The invention discloses an argon arc welding seam back face blowing protection device for a titanium alloy annular radiator. The argon arc welding seam back face blowing protection device comprises a protection cover, steel wool and an air guide pipe which are arranged in the protection cover, and a rectifying plate arranged at the upper end in the protection cover. The protective cover is composed of a side plate and a bottom plate with holes, the end of the side plate is provided with grid teeth with bending radian, and the radian of the grid teeth is determined according to the cambered surface of the annular radiator. Protective gas enters the gas guide pipe through the gas inlet in the bottom of the gas guide pipe, passes through the flow dividing pipe and then is exhausted through the guide-out pipe with the exhaust holes, the protective gas is disturbed by the steel wool filled in the protective cover after being exhausted through the guide-out pipe, the disturbed protective gas is exhausted out of air in the protective cover, and finally the protective gas is evenly exhausted through the rectifying plate. Therefore, the back of the argon arc welding seam is protected from being oxidized. The bent grid teeth are arranged at the ends of the side plates and can be bent according to the cambered surface of the annular radiator, so that the protection device is attached to the back face of a weld joint needing to be protected, and protection is sufficient.

The invention relates to the technical field of electrocatalysis, in particular to an oxygen / sulfur heterostructure oxygen evolution electrocatalyst and a preparation method and application thereof. Based on an in-situ oxidation strategy, a CuFeO layer is generated on the surface of CuFeS, and the CuFeS-coated CuFeO high-performance oxygen evolution electrocatalyst with a heterostructure is obtained. By constructing a sulfide-oxide heterojunction, a built-in electric field can be formed at an interface to promote charge separation and transfer, so that the electrocatalytic activity is remarkably improved. And on the other hand, the CuFeO layer on the outer layer serves as an armor, and the problem of oxidation of the surface of CuFeS is solved. The electro-catalytic performance and the long-term stability are obviously improved.

The present invention relates to the field of catalyst preparation, and in particular to the preparation of a peanut shell nitrogen-doped carbon-supported copper catalyst and its application in the synthesis of diethyl carbonate. The present invention adopts peanut shell as a raw material, and prepares a biomass carbon carrier by hydrothermal carbonization and co-pyrolysis. The raw material cost is low and it complies with the chemical principle of green and low carbon. Nitrogen is doped to adjust the composition and distribution of the pore structure. The prepared peanut shell nitrogen-doped carbon-supported copper catalyst has a pore structure with coexistence of micropores and mesopores, and a specific surface area of ​​up to 2731 m 2 •g ‑1 The surface of the carrier is rich in carbon defects and oxygen-containing functional groups, which is conducive to providing more active sites to anchor copper nanoparticles, thereby improving the dispersion of copper species and improving catalytic activity and stability. At the same time, the electron donation effect of N increases the Cu content in the catalyst. 0 and Cu + The generation and antioxidant capacity of the catalyst further improved the yield and activity.

The element welding rotary table based on the automatic directional transposition mechanism comprises a support, a rotary table is arranged on one side of the support, a rotary table is arranged on one side of the rotary table, and a jacking limiting mechanism and an air guide mechanism are arranged on one side of the rotary table; the sleeve rod is arranged on the rotary table, the sleeve rod is sleeved with a workpiece, then the workpiece is limited and fixed through the ejector block pushed out through air pressure in the sleeve rod, the workpiece can be welded, meanwhile, the air holes capable of exhausting are formed in the vertical rods, and then protective gas is guided into the workpiece, so that the workpiece can be welded. The problem of internal oxidation caused by high welding temperature is conveniently solved, and after workpiece welding is finished, the workpieces are lifted and supported out through the multiple brackets, so that the welded high-temperature workpieces can be rapidly stripped from the welding table, and the working efficiency is prevented from being affected.

The invention discloses an anti-oxidation production process of apple juice, which comprises the following steps: carrying out whole-process control such as cleaning, crushing, squeezing, storing and sterilizing on apples in a low-temperature environment so as to inhibit oxidation reaction and bacterium breeding; in the cleaning process, ozone water and RO water are adopted for fine cleaning, so that the cleaning and sterilizing effects of the apples are ensured; apples are crushed and oxygen is isolated through the crushing adsorption machine with a parallel blade structure; the totally-closed squeezing cavity is adopted for squeezing, and fruit juice oxidation is reduced; in the whole production process, air is isolated through nitrogen protection, and oxidation is delayed; the fruit juice is conveyed to a low-temperature storage tank and sterilized by adopting an HPP ultrahigh-pressure cold sterilization technology, so that the freshness, the taste and the flavor of the fruit juice are ensured; finally, the quality of the juice is preserved through cold-chain transportation; the invention solves the problem of oxidation discoloration of the apple juice caused by oxidase reaction in the existing juice production process, provides an effective anti-oxidation technology, and ensures the quality and stability of the apple juice.

The utility model relates to lithium ion battery technical field discloses a high solid content type lithium manganate production manganese dioxide chlorine element removal device, including mounting bracket and rotating plate rotation connection in the left and right sides of the inner wall of mounting bracket, still include: fixed in the left side of mounting bracket motor, and the output shaft of motor penetrates mounting bracket and is fixedly connected between the left rotating plate, the utility model has multiple dehydration function, this device can first to the wet manganese dioxide filter cake extrusion dehydration, can remove the large amount of free water in filter cake in advance, greatly reduce the water content required to remove subsequent drying, then continue to the wet manganese dioxide filter cake and rotate drying treatment, make the wet manganese dioxide filter cake and hot air can fully contact, accelerate the moisture evaporation rate, further improve the drying efficiency, effectively avoid the manganese dioxide oxidation problem caused by local temperature too high, guarantee the chemical property stability of manganese dioxide, ensure that the product quality is not influenced.

The invention discloses a gallium nitride HEMT (High Electron Mobility Transistor) device capable of monitoring temperature distribution in real time and a preparation method of the gallium nitride HEMT device. The device comprises a GaN buffer layer, a GaN channel layer, an AlGaN barrier layer, a P-GaN layer, a Ti / Al / Ni / Au ohmic contact layer, a SiNx isolation layer, a field plate, gate metal, a SiO2 passivation layer, a first metal layer, a first PI insulating layer, a first SiNx passivation layer, a second metal layer, a second PI insulating layer, a second SiNx passivation layer, a third metal layer, a patterned PI coating, an array temperature sensor and a PI passivation layer. The array temperature sensor is formed by connecting a TaN resistive film deposited by pulse laser, a carbon structure which is carbonized by direct writing of hundred TW / cm < 2 > magnitude high-intensity laser and takes graphene as a main part, and a copper nanowire electrode sintered by hundred TW / cm < 2 > magnitude high-intensity laser in a bridge manner. According to the gallium nitride HEMT device, the real-time accurate measurement of the heat distribution of the large-size packaged gallium nitride HEMT device can be realized.

The present invention discloses a vacuum welding device and method for amorphous alloys, and relates to the field of welding technology. The welding device includes a vacuum mechanism and a welding mechanism. The vacuum mechanism includes a vacuum cavity and a vacuum component arranged in the vacuum cavity for evacuating the vacuum cavity, and an optical lens is embedded in the vacuum cavity; the welding mechanism includes a laser and a welding component, the laser is arranged outside the vacuum cavity, and the emission port of the laser is arranged opposite to the optical lens, the welding component is arranged in the vacuum cavity, and the welding component has a welding platform for placing the workpiece to be welded, and the welding platform is arranged opposite to the optical lens. Through the arrangement of the vacuum mechanism and the welding mechanism, the device can use vacuum laser welding technology to weld amorphous alloys in a vacuum environment, effectively solve the problem of joint oxidation, and at the same time can be conducive to increasing the penetration depth, reducing the weld width and reducing the probability of defects such as pores and undercuts, thereby obtaining a good weld surface.

The application relates to a low-cost high-performance titanium-based composite plate preparation method. First, ingredients are prepared, smelting is carried out, an ingot is prepared, and a titanium-based composite slab is obtained through cutting. The raw materials include 3%-6% of high-purity Cr3C2 powder, and the balance is 0-grade titanium sponge particles; then the surface of the titanium-based composite slab is polished, alkali-washed, acid-washed, and air-dried, a high-temperature oxidation-resistant coating is coated on the surface of the slab, the slab is subjected to incremental gradient deformation hot rolling treatment, and the slab is air-cooled to room temperature to obtain a semi-finished titanium-based composite plate; finally, the plate is subjected to annealing treatment, the surface of the plate is polished, alkali-washed, acid-washed, and air-dried after the annealing treatment, and a finished titanium-based composite plate is obtained. The application shortens the hot rolling process, avoids the oxidation problem of the plate caused by multiple times of hot rolling treatment, effectively controls the distribution mode of the reinforcing phase in the titanium-based composite plate, realizes the uniform distribution of the reinforcing phase, and is simple in process, so the production cost is lower.

The invention discloses a semi-coke wastewater biochemical treatment system and a treatment process thereof, and relates to the technical field of semi-coke wastewater biochemical treatment, the semi-coke wastewater biochemical treatment system comprises a treatment system, the treatment system comprises an oil removal flotation module, an anaerobic module and a multi-stage anaerobic-aerobic module; the oil removal air floatation module comprises an oil separation tank, a buffer tank, an accident tank and an inert air floatation tank, and the oil separation tank, the buffer tank, the accident tank and the inert air floatation tank are connected with one another. Through combination of oil removal flotation, anaerobic treatment and multi-stage anaerobic-aerobic treatment, oil, phenols and other refractory organic matters in the wastewater can be effectively removed, and the biodegradability of the wastewater is remarkably improved. The oxidation problem of phenolic substances is avoided by adopting inert gas floatation, the toxicity of the wastewater is remarkably reduced by the composite anaerobic fluidized bed reactor, finally, organic pollutants are stably degraded by virtue of a multi-stage anaerobic-aerobic process, the concentration of the pollutants can be effectively reduced, the effluent quality is ensured to be stable and reach the standard, and the semi-coke wastewater treatment device is suitable for biochemical treatment of semi-coke wastewater.

The invention discloses a high-power graphite electrode for an electric arc furnace. The high-power graphite electrode comprises an electrode body and an electrode tip, the electrode body comprises a graphite base body, the whole graphite base body is of a drum-shaped cylinder structure, and a through inner hole is formed in the graphite base body to serve as an air hole; a plurality of long-strip-shaped blind grooves are evenly formed in the outer cylindrical surface of the graphite base body, and the long-strip-shaped blind grooves are annularly formed in the outer cylindrical surface of the graphite base body at intervals. The long-strip-shaped blind grooves are filled with superfine graphite filler, and the surface of the superfine graphite filler is flush with the outer cylindrical surface of the graphite base body; the outer cylindrical surface of the graphite substrate and the outer surface of the superfine graphite filler are coated with graphite fiber cloth, the outer side of the graphite fiber cloth is subjected to medium-temperature coal tar pitch dipping treatment, graphitization forming is carried out after secondary roasting to obtain an electrode body blank, and the surface of the formed electrode body blank is coated with a film protection layer. The erosion resistance and oxidation resistance of the graphite electrode can be remarkably improved, the service life of the graphite electrode is prolonged, and therefore the operation cost of the electric arc furnace is reduced.

A high-speed kneader for producing composite materials relates to the field of kneader technology and solves the problem of easy oxidation and performance degradation of composite materials during the kneading process in existing technologies. It includes a tank body, with a feeding tank connected to the bottom of the tank body. A discharge pipe is connected to the lower end of the feeding tank. An inlet pipe and a vacuum pipe are connected to the upper side wall of the tank body. A rotating shaft is coaxially rotatably connected to the tank body. The lower end of the rotating shaft is disposed inside the feeding tank. An air inlet is opened on the bottom end face of the rotating shaft, and multiple air outlets are evenly opened on the top side wall of the rotating shaft. An electric heating element is connected inside the rotating shaft, and multiple mixing blades are connected around the circumference of the rotating shaft. A material receiving plate is provided on the top of the feeding tank, and an air inlet pipe is connected to the side wall of the feeding tank. The beneficial effect is that it can inhibit the contact between materials and oxygen, improving the performance stability of composite materials.

The invention discloses a preparation process of a composite electrode for a ceramic chip, which comprises the following steps of: placing the ceramic chip in a clamping jig, thermally spraying an aluminum electrode layer on the surface of the ceramic chip through a first electrode spray gun, thermally spraying a copper electrode layer on the aluminum electrode layer through a second electrode spray gun, and performing nitrogen atomization spraying during spraying, and carrying out anti-oxidation treatment to obtain the ceramic chip of the composite electrode. The aluminum electrode layer and the copper electrode layer are sequentially sprayed on the surface of the ceramic chip, so that the binding force between the copper electrode layer and the ceramic chip can be improved; in the spraying process, nitrogen is adopted as compressed gas, so that the problem of oxidation of the ceramic chip can be avoided; the ceramic chip is subjected to anti-oxidation treatment, so that a stable anti-oxidation protection layer can be formed on the surface of the copper electrode layer, and the service life of a product is prolonged; the whole preparation process is reasonable in design, the structural stability, the conductivity and the durability of the ceramic chip electrode are effectively improved, and the overall performance of the product is improved.

The invention belongs to the technical field of nanocrystalline hard alloy, and discloses tungsten carbide-based nanocrystalline hard alloy and a preparation method thereof. The preparation method comprises the following steps that tungsten carbide powder is put into a modified solution containing soluble cobalt salt and soluble lanthanide series metal salt to be soaked, solid matter is collected, washed and dried after soaking is completed, and first powder is obtained; calcining the first powder in a reducing atmosphere to obtain second powder; and mixing the second powder, high-entropy metal carbide powder or high-entropy metal carbonitride powder and boron carbide powder, and then forming and sintering to obtain the tungsten carbide-based nanocrystalline hard alloy. The comprehensive effect of lanthanide series metal, high-entropy metal carbide powder or high-entropy metal carbonitride powder and boron carbide is utilized, and a novel introduction mode is adopted, so that the granularity of tungsten carbide is effectively inhibited, the nanocrystalline hard alloy with excellent hardness, obdurability and high temperature resistance is successfully prepared, and the practicability is very high.

The invention relates to the field of traditional Chinese medicine preparation preparation, and discloses an anti-fatigue Longquan drink preparation method, which comprises: 1, carrying out low-temperature steam distillation treatment on radix fici simplicissimae, and collecting the distillate; step 2, carrying out curing treatment on the distillate to obtain aroma powder; step 3, mixing dried mulberry leaves, dried papaya, fried coix seeds and the radix fici simplicissimae treated in the step 1, and performing water extraction to obtain a water extract; 4, alcohol extraction is conducted on the medicine residues, and alcohol extraction concentrated extract is obtained; step 5, performing juicing treatment on the bamboo and the sugarcane to obtain bamboo and sugarcane concentrated juice; step 6, combining the bamboo cane concentrated juice, the water extract and the alcohol extraction concentrated extract, refining, and spray-drying to obtain extracted powder; and 7, uniformly mixing the extracted powder with the aroma powder, and carrying out dry granulation. According to the preparation method of the anti-fatigue Longquan drink, by optimizing the preparation process, the symbolic coconut fragrance of the radix fici simplicissimae is reserved to the maximum extent, and the product has high identification degree and traditional identification sense.

The utility model discloses a high thermal insulation off-line coated hollow glass door body, which comprises a door frame, and on-line coated glass, a spacing bar and off-line coated glass which are sequentially fixed on the door frame from inside to outside, the off-line coated glass comprises a coated area overlapped with the on-line coated glass and a frame film removing area positioned at the peripheral edge of the coated area, and a cavity is formed among the coating area, the spacing bar and the on-line coating glass. According to the utility model, a hollow glass door body formed by arranging the off-line coated glass and the on-line coated glass from inside to outside is changed into a hollow glass door body formed by arranging the on-line coated glass and the off-line coated glass from inside to outside, so that the off-line coated glass with better thermal insulation performance is positioned on the outer side of the hollow glass door body, and the thermal insulation performance is improved; meanwhile, aiming at the problem of coating oxidation of the off-line coated glass, the frame of the off-line coated glass is subjected to film removal through a laser film removal technology to form a frame film removal area, so that oxidation is avoided.

A method for in-situ synthesis of PbCl2-coated PbSe quantum dots. The synthesis steps are as follows: mixing lead oxide (PbO), 1-octadecene (ODE), oleic acid (OA) and lead chloride (PbCl2), removing water oxygen in the reaction system under vacuum conditions, slowly heating to completely dissolve yellow PbO, then passing nitrogen and continuing to heat to temperature stability; injecting diphenylphosphine selenium (DPPSe) solution into Pb precursor solution, then slowly pushing into the mixed solution of diphenylphosphine (DPP) and tri-n-octylphosphine selenium (TOPSe) with a stepper motor to obtain PbCl2-coated PbSe quantum dots. By changing the amount of PbCl2, the particle size distribution of the synthesized PbSe quantum dots is controlled, and the finally prepared quantum dots have uniform particle size distribution and high air stability.

The nitrogen tunnel furnace with the vacuumizing function comprises a tunnel furnace body and a baking device, the tunnel furnace body comprises a feeding port and a discharging port, and the baking device at least comprises a baking box; one end of a feeding hole of the tunnel furnace body is hermetically connected with a baking box, and a baking chamber is formed in the baking box; a feeding door is formed in the end, away from the feeding port of the tunnel furnace body, of the baking box. The feeding door is provided with a feeding door plate which is used for opening or closing the feeding door; a discharging door is arranged at the end, connected with the feeding port of the tunnel furnace body in a sealed mode, of the baking oven, the discharging door is provided with a discharging door plate used for opening or closing the feeding door, and the discharging door directly faces the feeding port of the tunnel furnace body. A first pipeline is arranged on one side of the baking box, the first pipeline is communicated to the baking chamber, and the first pipeline is configured to be switched between vacuumizing of the baking chamber and nitrogen filling of the baking chamber. The problems that bubbles remain in AB glue and the AB glue is oxidized in the heating and curing process are effectively solved.

The invention relates to the technical field of epitaxial furnaces, and particularly provides an epitaxial furnace maintenance system and method. A maintenance chamber; an image acquisition assembly; a transfer chamber; the controller is used for controlling the first switch valve to be opened after the epitaxial growth process is completed, then moving the reaction cavity in the last half month to the position above the image acquisition assembly by utilizing the mechanical arm, and is also used for acquiring the image information of the bottom surface of the reaction cavity by utilizing the image acquisition assembly, then acquiring deposition particle parameter information according to the image information of the bottom surface of the reaction cavity and sending the deposition particle parameter information to the control module; analyzing whether the reaction cavity needs to be maintained in the last half month according to the deposited particle parameter information and preset particle parameters, if so, controlling a first switch valve to be closed, and generating maintenance reminding information; the system can effectively solve the problem that the graphite piece and the gas path element in the reaction chamber are oxidized due to contact between the graphite piece and the gas path element in the reaction chamber and air, and effectively improve the maintenance efficiency.

The application provides a ring-shaped combined structure ring seam laser welding method, which comprises the following steps: sequentially connecting multiple connecting rings and a bent pipe end to end to form a semi-ring-shaped combined structure; spot welding multiple welding points on any one ring-shaped welding seam; coating the outer surface of any one ring-shaped welding seam to prevent air leakage; injecting protective gas from one end of the semi-ring-shaped combined structure to exhaust the air in the semi-ring-shaped combined structure, then sealing the end of the semi-ring-shaped combined structure; welding the upper half of multiple ring-shaped welding seams by adopting a full-position welding process; turning over the semi-ring-shaped combined structure which has completed half of the welding; sequentially welding the other half of the multiple ring-shaped welding seams by adopting the full-position welding process; repeating the above steps to complete the welding of the other semi-ring-shaped combined structure. The two semi-ring-shaped combined structures which have completed the welding are connected by bolts and nuts to form a ring-shaped combined structure, which reduces the clamping requirement, simplifies the clamping process, reduces the turning over difficulty, and realizes self-locking butt joint assembly.