73results about How to "Improve diffusion efficiency" patented technology

The invention relates to the field of disposable hygienic products, in particular to a paper diaper with a fluffy non-woven fabric core body of a net structure and a preparation process of the paper diaper, and mainly solves the problems that in the prior art, macromolecular water-absorbent resin particles of an online water-absorbent paper core body are difficult to enter fluffy non-woven fabric, and the strength is poor. The paper diaper body comprises a liquid-permeable surface layer, an absorption core layer and a liquid-tight bottom layer which are sequentially stacked from top to bottom; the absorption core layer comprises a first fluffy non-woven fabric, a second fluffy non-woven fabric compounded on the lower surface of the first fluffy non-woven fabric and macromolecular water-absorbent resin particles laid on the upper surface of the first fluffy non-woven fabric; at least two material storage areas are arranged on the first fluffy non-woven fabric side by side in the transverse direction, holes are punched or embossed on the first fluffy non-woven fabric in each material storage area, and the macromolecular water-absorbent resin particles comprise first macromolecular water-absorbent resin particles which are distributed in each material storage area.

The invention provides a method for strengthening the coercive force of a neodymium-iron-boron magnet through composite reduction grain boundary diffusion, which comprises the following steps of: (1) mixing a reducing agent, a dispersing agent and a composite rare earth diffusion source to obtain mixed powder; the composite rare earth diffusion source comprises a multi-element rare earth compound diffusion source and / or a composite compound diffusion source; (2) coating the mixed powder obtained in the step (1) on the surface of a neodymium-iron-boron magnet to obtain a coating layer magnet; and (3) carrying out sectional composite reduction-grain boundary diffusion heat treatment and tempering treatment on the coated magnet in the step (2) to obtain the neodymium iron boron diffusion magnet. According to the method, the composite rare earth diffusion source is adopted, the preparation cost of the neodymium iron boron diffusion magnet is reduced, meanwhile, the grain boundary diffusion efficiency is improved, and the large-scale market application prospect is achieved.

The utility model discloses a multifunctional aroma diffuser capable of quickly diffusing aroma, which comprises a bottom shell provided with a spice storage cavity, spices capable of diffusing are arranged in the spice storage cavity, a surface cover is arranged at an opening of the bottom shell, and a power supply and a driving motor are arranged in the bottom shell; the top of the face cover is provided with a multi-layer vertical face fanning light-transmitting structural part which is fixed to a main shaft of the driving motor and generates breeze to achieve the function of a small fan during rotation. The driving motor drives the multi-layer vertical face fanning light-transmitting structural part to rotate, and the fragrance of the perfume is diffused outwards through the multi-layer vertical face fanning light-transmitting structural part. The fan is reasonable in structural arrangement, and the top of the face cover is provided with the multi-layer vertical face fanning light-transmitting structural part which is fixed to the main shaft of the driving motor and generates breeze to achieve the function of a small fan when rotating. The driving motor can drive the multilayer facade fanning light-transmitting structural member to rotate to generate gentle breeze to realize fanning, and the generated airflow can quickly diffuse fragrance, so that the diffusion efficiency of the fragrance is improved, and the effectiveness of aromatherapy is improved.

The invention relates to the technical field of oxygen reduction catalysts, in particular to a transition metal-based triatomic oxygen reduction catalyst and a preparation method and application thereof. The invention relates to a preparation method of a transition metal-based triatomic oxygen reduction catalyst. The preparation method comprises the following steps: dispersing carbon nanotubes in a solvent to obtain a dispersion liquid; adding transition metal acetate, urea and 4, 4 '-dihydroxy [1, 1'-biphenyl]-3, 3 ', 5, 5'-tetracarboxaldehyde into the dispersion liquid, performing ultrasonic treatment to obtain mixed liquid, and then performing heating reaction in an inert atmosphere; and after the reaction is finished, naturally cooling to room temperature, filtering, washing and drying to obtain the transition metal-based triatomic oxygen reduction catalyst. The catalyst designed by the invention not only has an efficient catalytic active site, but also remarkably improves the material transmission efficiency and enhances the utilization rate of a catalytic active center by optimizing the structure of a composite material, so that the synergistic enhancement of the electro-catalytic performance is realized.

The application belongs to the technical field of carbonyl sulfur hydrolysis catalysts, and discloses a high-efficiency sulfur-resistant catalyst for carbonyl sulfur hydrolysis, a preparation method and application thereof.The preparation method comprises the following steps: (1) preparing a porous ceramic carrier containing alumina, titanium dioxide and zirconium dioxide; (2) in-situ growing a metal organic framework material containing lanthanum, bismuth and cerium on the surface of the porous ceramic carrier by using a solvothermal method; (3) performing a calcination treatment on the porous ceramic carrier loaded with the metal organic framework material in an oxygen-containing atmosphere to obtain a catalyst precursor; and (4) performing a reducing gas plasma bombardment treatment on the catalyst precursor to obtain the high-efficiency sulfur-resistant catalyst.The high-efficiency sulfur-resistant catalyst has high-efficiency low-temperature activity, excellent sulfur resistance and long service life.

The invention discloses a lithium iron manganese phosphate composite material and a preparation method and application thereof, belonging to the technical field of lithium batteries. The composite material comprises the following raw materials: a lithium source, a manganese source, an iron source, phytic acid, graphene oxide, polyvinyl alcohol, pyrrole and a dopant. The invention adopts a hydrothermal method to make hydroxyl groups on the surface of graphene oxide react with phytic acid to obtain a mixed solution a, and similarly obtains a mixed solution b containing polyvinyl alcohol phytate, combines a manganese source, a lithium source and an iron source, prepares a semi-finished product by roasting, and then coats a doped polypyrrole layer on the surface of the semi-finished product to finally obtain a lithium iron manganese phosphate composite material with a three-dimensional structure. The three-dimensional structure is a composite structure of a rod-like structure and a sheet structure. Compared with the lithium iron manganese phosphate material with a single morphology in the prior art, the specific surface area is significantly improved, the stability is stronger, the contact area with the electrolyte is larger, and the diffusion efficiency of lithium ions and the charge and discharge performance of the battery are improved.

The invention discloses a cobalt-free lithium-rich manganese-based oxide material for a lithium ion battery and a preparation method thereof.The preparation method comprises the steps that a lithium source and a precursor in a preset proportion are mixed and ball-milled to obtain a mixture, and then the mixture is subjected to first calcination to obtain a first reactant; the first reactant is soaked in a citric acid ethanol solution, magnetic stirring is carried out at the same time, the soaked first reactant is subjected to second calcination, and a second reactant with the surface coated with a spinel phase is obtained; mixing and stirring a second reactant and an aluminum source according to a preset proportion, and performing third calcination on the stirred second reactant to enable the aluminum element to enter a lattice structure of the second reactant to obtain a third reactant; and calcining the carbon source and the third reactant together to obtain the cobalt-free lithium-rich manganese-based oxide material for the lithium ion battery coated with the carbon layer. The cobalt-free lithium-rich manganese-based oxide material for the lithium ion battery, which is obtained by the method, shows better cycling stability.

The invention provides a preparation method of a high-performance grain boundary diffusion sintered neodymium iron boron material, and belongs to the technical field of permanent magnet materials. The low-melting-point heavy-rare-earth-free alloy coating is coated and cured on the easy-to-diffuse surface of the neodymium-iron-boron base material magnet, and the heavy-rare-earth alloy coating is coated and cured on the low-melting-point heavy-rare-earth-free alloy coating; and the coated magnet is sequentially subjected to low-temperature pre-diffusion heat treatment, grain boundary diffusion heat treatment and aging treatment, and then the grain boundary diffusion neodymium-iron-boron magnet is obtained. According to the invention, the diffusion efficiency of heavy rare earth elements can be effectively improved, the coercive force of the magnet is improved, and relatively high residual magnetism can be achieved.

The utility model discloses a Mylar film structure for aluminum shell battery, aluminum shell battery and electronic product belong to battery technical field, including Mylar film body, Mylar film body includes first cladding piece, second cladding piece and the connecting cladding piece of first cladding piece and second cladding piece are connected respectively, recesses is formed in first cladding piece and is used to store the first liquid storage groove of electrolyte, recesses is formed in second cladding piece and is used to store the second liquid storage groove of electrolyte, first liquid storage groove and second liquid storage groove all are located on the side surface of battery roll core. The utility model reaches the technical effect of improving diffusion efficiency, and promotes the long -term cycle performance of battery.

The application provides a positive electrode active material, a preparation method of the positive electrode active material and a potassium ion battery, and relates to the field of secondary batteries. The positive electrode active material comprises a core and a carbon layer covering the core, and the chemical formula of the core is K 3+x V 3‑x Ni x (PO4)4, 0.05<=x<=0.5. In the application, Ni 2+ is doped in the KVP material, so that the structural stability and the electrochemical performance of the positive electrode active material are effectively improved. Specifically, by doping Ni 2+ , the product purity and the crystalline integrity of the positive electrode active material are significantly improved, the structural stability of the product is enhanced, and the problems of low product purity and many impurities in the existing preparation method are solved. Moreover, the reaction kinetics and the cycle performance of the positive electrode active material are synergistically optimized.

The utility model discloses a fogging disinfection device for central air conditioning, including air duct, air duct bottom is equipped with air duct flange, air duct below is equipped with solution tank, the top of solution tank is equipped with the solution tank flange of air duct flange adaptation, air duct inside is equipped with the two piece microporous ceramic atomizing piece of inclination setting, the surface of microporous ceramic atomizing piece is equipped with annular piezoelectric driver, the cavity is formed between microporous ceramic atomizing piece, the inside of cavity is equipped with atomizing nozzle, the atomizing nozzle is extended to the inside of solution tank through hose, the utility model discloses through secondary atomization processing, and the disinfectant spreads along the direction of air current, plays good atomization efficiency processing effect, and the effect of atomization diffusion is effectively improved with the air direction and the inclination direction of microporous ceramic atomizing piece, and the efficiency of diffusion is improved.

The application provides an image encryption method based on ring rotation and generalized Feistel cipher structure. The method comprises the following steps: generating a chaotic sequence by a hyperchaotic Chen system, and performing ring rotation twice on a plaintext image to realize efficient global scrambling; then, a one-dimensional chaotic system 1DL-SCS is used to perform line-by-line index scrambling on the image, and then the pixel points are redistributed column by column to further break the correlation between the pixels; in the diffusion stage, the plaintext is divided into four parts, substituted into an improved generalized Feistel cipher structure for calculation, and further divided into two parts in the round function, so that the diffusion efficiency is greatly improved, and through two rounds of iteration operation, a good encryption effect can be obtained, and the security is high.

This invention discloses the application of an electrode material for reducing intracellular resistance genes in drug-resistant bacteria. A platinum-doped dendritic TiO2 nanowire structure based on a three-dimensional material is formed by growing a micron-sized TiO2 backbone array and platinum-doped nano-sized TiO2 branches on the surface of a porous electrode. The prepared dendritic nanowire three-dimensional electrode material has a larger specific surface area, providing more reactive sites and strong electric field sites. Platinum doping enhances the conductivity and electrocatalytic performance of the nanowires. Furthermore, by combining it with chloride salts / oxidants, the electroporation and electrocatalysis of the nanowire electrode surface are coupled. The strong electric field confined at the nanowire tip induces perforation of the drug-resistant bacterial cell structure, strengthening the contact and reaction between the oxidant and the resistance gene. The high electrocatalytic activity confined at the nanowire tip induces the generation of strong oxidizing free radicals, achieving the goal of destroying the drug-resistant bacterial cell structure and efficiently reducing intracellular resistance genes.

The application discloses a preparation method of nanosheet TS-1 molecular sieve and application thereof, relates to the technical field of catalysts, and synthesizes the TS-1 molecular sieve through a double quaternary ammonium salt structure directing agent containing a benzene ring; the obtained TS-1 molecular sieve has rich surface active sites and contains almost no impurities such as non-framework titanium and anatase TiO2; meanwhile, the nanosheet morphology significantly improves the diffusion and mass transfer performance of macromolecular reactants in a catalytic process, effectively enhances the accessibility of active sites; in a cyclohexene epoxidation reaction, the molecular sieve exhibits excellent catalytic performance and shows good application prospect; and the problems of significant channel diffusion limitation and low accessibility of active sites of the TS-1 molecular sieve in a catalytic process are solved.

The application discloses a kind of perovskite laminated solar cell and preparation method thereof, photovoltaic module and photovoltaic device, belong to solar cell technical field.The perovskite laminated solar cell from light-receiving front to light-receiving back successively includes substrate, bottom electrode, first hole transport layer, wide band gap perovskite layer, first electron transport layer, barrier layer, intermediate interconnection layer, narrow band gap perovskite layer, second electron transport layer, hole blocking layer, top electrode;The intermediate interconnection layer includes first sublayer, self-assembled monolayer and second sublayer, first sublayer faces first electron transport layer, second sublayer faces narrow band gap perovskite layer, and self-assembled monolayer is located between first sublayer and second sublayer.The application can inhibit interface scattering and reduce wide-angle reflection loss under oblique incidence, while maintaining excellent electrical transmission to promote carrier transfer and recombination, significantly improve the overall photovoltaic performance of device.

This invention relates to the field of titanium alloy chemical heat treatment technology, specifically to a method for preparing a nitrided layer in titanium alloy using ion implantation-assisted plasma nitriding and its application. First, the titanium alloy is polished. Then, different dosages of Ti-La elements are implanted into the surface of the titanium alloy using ion implantation technology. Finally, the implanted titanium alloy is subjected to plasma nitriding. The purpose of this invention is to pre-introduce vacancies, dislocations, and other crystal defects on the surface of the titanium alloy using high-energy ion implantation technology, increasing the nitrogen diffusion channels during the nitriding process and improving nitriding efficiency. Under the same nitriding conditions, a thicker nitrided layer can be achieved. Simultaneously, the extremely fine nitride nucleation formed on the surface under the catalysis of La results in a denser surface, achieving higher surface hardness under the same conditions. This helps improve the mechanical, tribological, and fatigue properties of titanium alloys, and can be applied in aerospace, biomedical devices, and marine equipment fields.

The invention discloses a preparation method of a catalyst for preparing acetaldehyde from ethanol, and belongs to the technical field of chemical synthesis, and the method comprises the following steps: dissolving a metal salt in deionized water, adding a silicon source and a template agent, adjusting the pH value, atomizing the solution, and carrying out aerosol spray drying to form a catalyst precursor; immersing the precursor into a dopamine-Tris buffer solution, and performing in-situ polymerization to form a polydopamine shell layer; and performing high-temperature carbonization and hydrogen reduction to obtain the catalyst. The method comprises the following steps: adding a catalyst into a reaction tube, fixing in a fixed bed reactor, preheating ethanol, introducing into the fixed bed reactor, reacting on the surface of the catalyst to generate acetaldehyde and hydrogen, condensing and separating acetaldehyde, and collecting hydrogen through a gas device arranged at the outlet of the reactor. According to the invention, the problems of low acetaldehyde selectivity, easy sintering deactivation of the catalyst and the like in the prior art are solved, the acetaldehyde selectivity is effectively improved, and the service life of the catalyst is prolonged.

The utility model provides a hydrogen peroxide atomizing sterilizer, which relates to the technical field of sterilizing equipment and comprises a shell, a disinfectant box, a fan, at least one atomizing nozzle and a vaporization cavity, the atomizing nozzle is connected with the vaporization cavity, and the fan and the disinfectant box are respectively connected with the vaporization cavity through hoses. A lifting assembly used for driving the atomizing nozzle is arranged in the shell, the lifting assembly is an electric push rod, a guide hole allowing the vaporizing cavity to slide vertically is vertically formed in the shell, the electric push rod is vertically arranged in the shell, and the output end of the electric push rod is connected with the bottom of the vaporizing cavity. According to the hydrogen peroxide atomization disinfection machine, the height of the atomization spray head is changed through the lifting assembly, so that the atomization spray head can spray a disinfectant to spaces with different heights, the diffusion efficiency of the disinfectant in the spaces is improved, the diffusion uniformity of hydrogen peroxide gas is improved, and finally the disinfection and sterilization effects are improved.

The invention relates to the cross technical field of sodium-ion batteries and glass preparation, in particular to a sodium-ion battery negative electrode material and a preparation method thereof, and the sodium-ion battery negative electrode material comprises a current collector and a composite active coating attached to the current collector; the composite active coating is formed by coating and drying slurry, and the slurry comprises a glass material, a conductive material and a binder. According to the invention, the glass material is introduced into the composite active coating, so that the structural stress in the sodion deintercalation process is effectively buffered, and the phase change and structural collapse of the electrode material are inhibited, thereby remarkably improving the cycling stability; meanwhile, the ion diffusion rate and the electron conduction efficiency are enhanced and the rate capability and the capacity performance are improved by a three-dimensional conductive network formed by the glass material, the conductive material and the binder in a synergistic manner, the overall preparation process is simple, the cost is relatively low, and a feasible material solution is provided for high-performance application of the sodium-ion battery in the field of large-scale energy storage.

The present invention relates to a particle fusion supercritical compression foaming production process and device, and belongs to the field of supercritical foaming technology. In the foaming method provided by the present invention, by increasing the gas-solid interface of the material, short-distance diffusion is carried out in units of polymer particles, the swelling time is shortened, and at the same time, the advantage of the compression foaming process in producing large-sized foam materials is ensured by utilizing one-piece molding in a confined space. In addition, the present invention also adopts the design of inner and outer molds, wherein the inner mold can be replaced in size and shape, which improves the utilization rate of the equipment itself and the product diversification to a certain extent. That is, the new method of this patent adopts particle fusion technology to effectively overcome the shortcomings of supercritical compression foaming and utilizes the design of one-piece molding and double molds to fully retain its advantages, which is very important for the industrial development of this technology.

The utility model discloses a semiconductor optical glass batch mixer, and belongs to the technical field of semiconductor optical glass production equipment. A semiconductor optical glass batch mixing machine comprises a mixing shell, an access cover, a feeding hopper, a conveying pipe and a rotating mechanism, the conveying pipe is rotatably arranged on the access cover in a penetrating mode, a driving shaft is rotatably connected into the conveying pipe, a first auger blade is fixedly connected to the driving shaft in a sleeving mode, and a plurality of guide pipes are fixedly connected to the conveying pipe; and a plurality of discharging pipes are fixedly connected to the lower side of the material guiding pipe. According to the technical scheme, by arranging the material guiding pipe and the material discharging pipe, when glass raw materials are mixed, the first auger blade rotates, an additive is input into the material guiding pipe and can be dispersed to all positions of the raw materials in the material mixing shell through the material discharging pipe, and the uniform mixing efficiency is effectively improved; and the material guide pipe not only can stir the raw materials, but also can further improve the diffusion efficiency of the additive.

The invention belongs to the technical field of new energy materials, and particularly relates to a secondary battery and electric equipment. Compared with the prior art, by selecting the first active substance and the second active substance with specific compositions and matching with the arrangement of the first coating and the second coating, the energy density of the battery can be improved, and the first coulombic efficiency and the cycle performance can be improved. Specifically, a soft carbon and hard carbon composite material is matched with a graphite coated hard carbon material, so that the energy density can be improved; the first element and the second element are adopted to dope the active substance, so that the conductivity of the negative electrode plate can be improved, the ion diffusion kinetics is improved, and the de-intercalation of sodium ions is facilitated; meanwhile, the arrangement of the double active material coatings is adopted, so that the ion diffusion efficiency can be improved, the de-intercalation of sodium ions is accelerated, the first coulombic efficiency is improved, and the cycle performance of the battery is improved.

This invention discloses a grinding wheel and a silicon carbide electrochemical nanogrinding method using the same. The grinding wheel includes a grinding wheel ring, grinding wheel blocks, and an ultrasonic vibration module; multiple grinding wheel blocks are arranged at intervals at the bottom of the grinding wheel ring, and the ultrasonic vibration module is installed at the top of the grinding wheel ring; each grinding wheel block includes a core and an outer layer surrounding the core; the core has a porous structure; the outer layer is made of composite abrasive particles, active metal, carbon fiber, and a conductive binder, and the composite abrasive particles, active metal, and carbon fiber are embedded within a conductive matrix formed by the conductive binder. The grinding wheel proposed in this invention can effectively enhance the grinding force and grinding ratio of the grinding wheel, thereby significantly improving the grinding efficiency when used for electrochemical nanogrinding; on the other hand, it can significantly reduce the wear and damage of the grinding wheel during electrochemical nanogrinding, thus extending the service life of the grinding wheel.

The invention relates to the technical field of carbon dioxide capture and adsorption, in particular to a calcium oxide-based adsorbent for high-temperature carbon dioxide capture and a preparation method. The adsorbent comprises a biomass calcium carbonate matrix, a skeleton proppant, a Ce-Zr-Cu composite oxide bifunctional aid, a conductive dispersant, a macropore-mesopore-micropore hierarchical porous structure formed by biomimetic mineralization of a biological template agent, and an amino functional group grafted by a surface modifier. The biomass calcium carbonate matrix is formed by compounding egg shells, shells and coral bones according to the mass ratio of 1: 1: 0.5; the skeleton proppant is formed by compounding a ZSM-5 molecular sieve and mesoporous gamma-aluminum oxide according to a mass ratio of 2: 1; in the scheme, biomimetic mineralization is realized by compounding a ZSM-5 / gamma-alumina skeleton and a Ce-Zr-Cu ternary auxiliary agent, introducing a PAN-based nitrogen-doped carbon network and matching with a diatom-egg white biological template, and APTES + PEI surface modification is performed, so that the problems of poor sintering, poor circulation, agglomeration and the like of a traditional adsorbent are solved in a targeted manner, double-temperature-zone adsorption is also realized, and the comprehensive performance is greatly improved.

The utility model relates to the field of sewage treatment, in particular to a conditioning tank for advanced sludge treatment, which comprises a tank body and a power shaft coaxially fixed in the tank body, a stirring impeller for stirring sludge and a conditioning agent is coaxially arranged on the power shaft, and a sludge feeding port is arranged on the tank wall of the tank body; a diffusion impeller located on a sludge falling path is arranged in the tank body, the axis of the diffusion impeller is arranged in the radial direction of the tank body, all blades of the diffusion impeller gradually expand outwards in the direction away from the sludge feeding opening to form a horn-mouth-shaped structure, and the diffusion impeller is driven by a power source to rotate so as to scatter the falling sludge. According to the utility model, the sludge conditioning time is greatly shortened, and the conditioning efficiency is improved.

The utility model discloses a silicon wafer diffusion device and gas source diffusion quartz boat, this silicon wafer diffusion device includes first end plate and second end plate, and the first end plate and second end plate are connected with support column, and support column is spaced apart and is provided with multiple rows along the preset direction, and the installation space of accommodating silicon wafer is formed between every two adjacent rows of support column. First end plate and second end plate all have first preset area, and first preset area is equipped with the first air hole of intercommunication installation space, and first preset area is opposite with the junction area of two adjacent installation spaces. This silicon wafer diffusion device can bear multiple rows of silicon wafer, to carry out diffusion process to multiple rows of silicon wafer simultaneously, improve diffusion efficiency. The first air hole provides the junction area of two adjacent installation spaces with airflow circulation channel, and airflow can more evenly circulate the whole silicon wafer diffusion device, solve the problem of insufficient air flow between two adjacent rows of silicon wafer, improve the square resistance uniformity and film thickness uniformity of silicon wafer after diffusion process, reduce production cost.

The invention discloses a miniature unmanned ship and a water quality detection and oxygenation method thereof, and the miniature unmanned ship is used for water quality detection. Comprising a ship body, a jet device, an oxygenation device and a water quality detection device, the water quality detection device is used for detecting the oxygen concentration in water after arriving at a set point, and comparing the oxygen concentration with the set normal oxygen concentration for analysis; the jet device is connected with the oxygenation device, the oxygenation device is used for mixing and micronizing air, and the treated air is jetted into water through the jet device to form a large number of bubbles so as to increase the oxygen concentration in the water; according to the unmanned ship, air can be efficiently mixed and micronized, the treated air is jetted into water through the jet device, and a large number of fine bubbles are formed; the bubbles can be quickly dissolved in water, so that the oxygen concentration in the water is improved, and the water quality is effectively improved; and efficient and accurate detection and oxygenation treatment of water quality are realized.

The utility model provides insect trapping and killing equipment for rice diseases and insect pests. Comprising a supporting rod and a connecting block, a lamp cylinder is installed on the connecting block, a top plate is installed on the lamp cylinder, a lifting cover is arranged in the top plate, a medicine containing box is installed below the lifting cover, a connecting cylinder is installed below the lamp cylinder, and a draught fan is installed in the connecting cylinder. According to the LED lamp tube, pests can be attracted through the light source and the pheromones at the same time, heat can be released in the working process of the lamp tube, the diffusion range and efficiency of the pheromones can be improved in cooperation with the draught fan due to the fact that movement between molecules is quickened along with temperature rising, and the pest attracting effect can be effectively improved; pests can be killed under the action of current after making contact with the electric net cover, meanwhile, the surface of the electric net cover is effectively cleaned through an insulation brush driven by a motor, residual of pest bodies is avoided, and the high practicability and the high pest killing effect are achieved.

The invention discloses a D-A type covalent organic framework material as well as a preparation method and application of the D-A type covalent organic framework material. The material is obtained through aldehyde amine condensation by using N, N ', N'-tetra (p-aminophenyl) p-phenylenediamine (TAPB) as a donor unit and 3, 6-bis (5-aldehyde thiophene-2-yl)-2, 5-bis (2-ethylhexyl) pyrrolo [3, 4-c] pyrrolo [3, 4-c] pyrrole-4 (2H, 5H)-diketone (DSZ) as an acceptor unit, and the material is of a two-dimensional layered porous structure, is dark blue and has reversible switching electrochromic performance from dark blue to nearly transparent color. According to the invention, a donor-receptor type covalent organic framework structure is constructed through TAPB and DSZ, and reversible color change from dark blue to nearly colorless in a near-infrared region is realized by using synergistic oxidation reduction of a D-A unit and charge transfer characteristics of a conjugated framework.

The invention provides a platinum-bismuth alloy catalyst, a preparation method thereof and a direct methanol fuel cell, and belongs to the technical field of electrochemical catalysts. The method comprises the following steps: mixing carbon black with an acidic aqueous solution, and sequentially carrying out acidizing treatment and roasting treatment to obtain pretreated carbon black; mixing the pretreated carbon black, Bi2O2CO3, a platinum source, a precipitant, a pH regulator, a first dispersing agent and first water, and performing replacement reaction to obtain a suspension; mixing a reducing agent, a second dispersing agent and second water to obtain a mixed solution; dropwise adding the suspension into the mixed solution for reduction reaction to obtain a catalyst precursor; and calcining the catalyst precursor under first protective gas to obtain the platinum-bismuth alloy catalyst. The prepared platinum-bismuth alloy catalyst has excellent electro-catalytic performance, shows relatively high catalytic activity and cycling stability, and can be applied to oxygen reduction reaction of a cathode of a direct methanol fuel cell.