852results about How to "Large specific surface area" patented technology

The invention provides a chemical restoration method for treating heavy metal-polluted terrain soil by ferromagnetic artificial nucleuses. In a ferromagnetic artificial nucleus soil restoration method, the ferromagnetic artificial nucleuses are applied to heavy metal-polluted soil; soil above a heavy metal pollution depth is overturned by cultivation equipment to uniformly mix with the ferromagnetic artificial nucleuses; and after heavy metal can be dispersed from the soil to the artificial nucleuses by a period of time, the soil containing the artificial nucleuses is overturned by using the cultivation equipment to increase the change of the artificial nucleuses contacting with other soil. After the soil overturning procedure is repeated by multiple times, the cultivation equipment provided with magnets can be used for separating the ferromagnetic artificial nucleuses, absorbed with the heavy metal, from the polluted soil; and the content of the heavy metal of the polluted soil is reduced due to shifting-out of the ferromagnetic artificial nucleuses, so that the purpose of soil restoration is gradually achieved.

This invention discloses a method for preparing a heavy metal ion adsorbent, the heavy metal ion adsorbent itself, and its applications. The preparation method includes the following steps: obtaining a mixture of steel slag and red mud; adding water to the mixture obtained in the above step and wet-milling it using a ball mill to obtain slurry 1; introducing CO2 gas into slurry 1 under stirring conditions to carbonize the modified porous framework particles in slurry 1 to obtain slurry 2; and filtering slurry 2 to obtain a solid, washing the solid until the pH is neutral, and drying it to obtain the heavy metal ion adsorbent. This invention uses two industrial solid wastes, steel slag and red mud, as reaction raw materials, resulting in low cost. It prepares a porous adsorbent material loaded with nano-calcium carbonate at room temperature, exhibiting high adsorption efficiency, and realizing high-value utilization of steel slag and red mud for wastewater treatment.

The invention relates to a uniform carbon-coated mesoporous silicon carbon negative electrode material and a preparation method and application thereof.The preparation method comprises the steps that a product obtained after pyrolysis and carbonization of a biomass carbon source is subjected to alkali activation treatment, acid pickling, drying, smashing, passivation, water washing and drying are conducted to obtain a mesoporous carbon matrix, nanometer silicon particles are deposited in pores of the mesoporous carbon matrix, and the uniform carbon-coated mesoporous silicon carbon negative electrode material is obtained. Then selecting a low-temperature carbonization material and polyethylene glycol to perform pre-carbonization and complete carbonization treatment on the mesoporous silicon carbon material to obtain a carbon coating layer, and finally obtaining the uniform carbon-coated mesoporous silicon carbon negative electrode material. When the uniform carbon-coated mesoporous silicon carbon negative electrode material is applied to a lithium battery, the mesoporous skeleton can effectively inhibit volume expansion of silicon in a battery circulation process, and the uniform carbon-coated layer can effectively reduce the risk of direct contact between the negative electrode material and an electrolyte, so that a stable SE I film is formed to reduce the occurrence of side reactions; and the first coulombic efficiency and the cycle performance of the battery are further improved.

The application belongs to the technical field of polymer materials, and particularly relates to a high-performance fiber composite material and a preparation method thereof. The preparation method of the high-performance fiber composite material comprises the following steps: adding pretreated aluminum oxide whiskers into a solvent, then adding pretreated carboxymethyl cellulose and gallic acid, and heating to reflux to obtain modified aluminum oxide whiskers; then mixing epoxy resin, the modified aluminum oxide whiskers, a curing agent and an accelerator uniformly to coat a film to obtain a resin adhesive film; and compounding the resin adhesive film and carbon fibers through hot pressing to obtain carbon fiber prepreg, and heating and curing the obtained prepreg to obtain the high-performance fiber composite material. The fiber composite material obtained by the application not only has high strength and rigidity, but also has excellent toughness, can effectively resist the impact of the external environment, has oxidation resistance and long-term stability, and has a wide application prospect in the fields of aerospace and new energy equipment.

The application discloses a biomimetic urchin-shaped asymmetric structure composite phase change chitosan aerogel loaded with TiO2 / rGO heterojunction and a preparation method and application thereof, adopts argon plasma etching GO, step-by-step dropwise adding tetrabutyl titanate to prepare TiO2 / rGO heterojunction; prepares a multi-level structure phase change microcapsule by an interfacial polymerization method; mixes the heterojunction with a chitosan solution, and prepares a biomimetic urchin-shaped asymmetric chitosan aerogel framework through a customized asymmetric mold and a unidirectional freezing process; fixes the phase change microcapsule by a vacuum-assisted impregnation method, and then performs in-situ coating through polydopamine to obtain the biomimetic urchin-shaped asymmetric structure composite phase change chitosan aerogel loaded with TiO2 / rGO heterojunction, the removal rate of VOCs of the biomimetic urchin-shaped asymmetric structure composite phase change chitosan aerogel loaded with TiO2 / rGO heterojunction is greater than or equal to 80% at low temperature, the phase change microcapsule dispersion rate is less than or equal to 3% after 100 cycles, the structural stability and the cycle durability are excellent, and the biomimetic urchin-shaped asymmetric structure composite phase change chitosan aerogel loaded with TiO2 / rGO heterojunction is suitable for efficient purification of VOCs in low-temperature closed scenes such as cold chain workshops and indoor environments in winter.

This invention provides a coal tar pitch-based nickel catalyst, its preparation method, and its application, belonging to the field of solid waste resource recycling and synthetic carbon materials technology. This invention uses a mixed roasting method to prepare a coal tar pitch-based nickel catalyst with micropores and mesopores from the residual coal tar pitch after coal tar extraction. The synergistic effect of active nickel as an active site and the functional groups on the support surface significantly improves its catalytic liquefaction performance, exhibiting the advantages of "low cost, high temperature resistance, and strong adaptability." The preparation method provided by this invention not only offers an effective way for the high-value recycling of coal tar pitch but also provides a low-cost material for green conversion, environmental governance, catalysis, and other fields. It represents a green resource utilization strategy with significant economic and environmental benefits and broad commercial prospects.

The invention provides an electrochemical method, an electrode and a system for synthesizing hydrogen peroxide without aeration, and relates to the technical field of electrochemical preparation of hydrogen peroxide. The multistage hole penetrating type cathode with a specific multistage hole channel structure is adopted, the oxygen-containing electrolyte penetrates through the multistage hole penetrating type cathode for electrochemical reaction under the non-aeration condition, dissolved oxygen in fluid is forced to make efficient contact with catalytic active sites through the multistage hole channel structure, the mass transfer process is greatly enhanced, and the catalytic activity of the catalyst is improved. And the diffusion limitation of the traditional flow-through electrode is overcome. And meanwhile, the structure required for synthesizing hydrogen peroxide is simplified by an aeration-free operation mode, and the energy consumption and the cost are reduced. Finally, through the synergistic effect of the technical characteristics, the high-yield and high-flux synchronous output of hydrogen peroxide can be realized under the condition that an expensive catalyst and external gas aeration are not needed.

The application discloses an electrolytic synthesis method of 3,6-dichloropicolinic acid, which comprises the following steps: S1, adopting a diaphragm electrolytic cell, taking an aqueous solution containing 3,4,5,6-tetrachloropicolinic acid and CO2 gas as the cathode liquid, taking an aqueous solution of alkali metal hydroxide as the anode liquid, taking a rhodium modified foam nickel electrode as the cathode, and taking a nickel-based material as the anode to perform an electrolytic reaction; and S2, after the reaction is completed, performing acid precipitation and filtration to obtain 3,6-dichloropicolinic acid. The cathode material is improved, the rhodium modified foam nickel electrode is used to replace the traditional silver mesh electrode, the three-dimensional porous structure of the foam nickel and the high catalytic activity of rhodium are utilized, the electrolytic efficiency is improved, the energy consumption is reduced, and meanwhile, the high product yield is maintained.

This invention belongs to the field of gas sensor technology and discloses a method for preparing europium ferrite nanosensors and their applications. This method utilizes electrospinning technology combined with a specific low-temperature confined-domain calcination process (550℃~700℃) to prepare EuFeO3 nanotubes with a hollow structure and rough surface by taking advantage of the thermal decomposition kinetics differences of poly(p-v) magnets (PVP). This process effectively suppresses excessive repair of lattice oxygen while forming a unique tubular morphology, effectively "freezing" oxygen vacancies (O2) accounting for up to 34.44% on the material surface in situ. v This invention addresses the shortcomings of traditional solid fiber materials by constructing a sensor using a grinding, dispersion, and coating process. Utilizing the dual reactive surfaces of hollow nanotubes and high-concentration oxygen vacancy active sites, it achieves highly sensitive and selective detection of low-concentration ethylene gas released during fruit ripening. This invention solves the problems of small specific surface area and insufficient active sites in traditional solid fiber materials.

The invention belongs to the technical field of synthesis of 2, 3-dipicolinic acid, and relates to a catalyst for synthesizing 2, 3-dipicolinic acid as well as a preparation method and application thereof, the catalyst is prepared from a carrier, and active components and auxiliaries loaded on the carrier; the carrier is boron nitride modified aluminum oxide, the active component is palladium-cobalt bimetal, and the auxiliary agent is magnesium; the catalyst comprises the following components in percentage by mass: 0.2 wt%-3wt% of palladium, 0.5 wt%-4wt% of cobalt, 0.05 wt%-0.3 wt% of magnesium, 5wt%-15wt% of boron nitride and the balance of an aluminum oxide carrier. The catalyst is prepared by adopting an ultrasonic-assisted sol-gel method, so that high dispersion and strong interaction of active components are realized. The catalyst shows high catalytic activity, high selectivity and excellent stability in a dichloropyridine carbonylation reaction, carbon monoxide is used as a carbonyl source, the atom economy is high, and the green chemical requirement is met.

The invention provides a nitrogen-doped hierarchical pore carbon material as well as a preparation method and application thereof, and the preparation method comprises the following steps: sequentially dissolving urea, alkali metal hydroxide and / or a pore-forming agent in water to obtain a mixed solution, cooling the mixed solution, adding cellulose-based biomass, and dissolving the cellulose-based biomass to obtain transparent sol; freezing the transparent sol into a solid, and performing vacuum freeze drying to obtain a white loose solid; mixing and grinding the liquid polymeric monomer and the white loose solid, and performing heat treatment to obtain a solid product; and carbonizing the solid product in an inert atmosphere, and then pickling and washing the carbonized product. According to the preparation method, chain-shaped arrangement in cellulose-based biomass molecules is converted into three-dimensional net-shaped arrangement through dissolution, macropores are formed, a macropore framework is kept stable and does not collapse in the carbonization process through polymerization reaction, and the formed hierarchical pore carbon material has a micropore / mesopore / macropore coexisting three-dimensional structure and controllable specific surface area and pore size distribution; meanwhile, in-situ nitrogen doping can also be realized.

The application discloses a mesoporous carbon preparation process with recyclable silicon source and mesoporous carbon with small pore size and large specific surface area. The mesoporous carbon preparation process comprises the following steps: preparing a silicon template: reacting a fluosilicic acid solution with calcium carbonate, and separating calcium fluoride precipitate and silica sol; the pH of the silica sol is 2-5; the concentration of silicon dioxide in the silica sol is 1-8 wt%; preparing a precursor: dissolving a carbon source and an organic acid in the silica sol, drying, grinding, and carbonizing in an inert atmosphere to obtain a C / Si precursor; the organic acid comprises at least one of oxalic acid, tannic acid, acetic acid and citric acid; removing the silicon template and recycling the silicon source: treating the C / Si precursor with hydrofluoric acid, and performing solid-liquid separation to obtain mesoporous carbon and a fluosilicic acid solution, wherein the fluosilicic acid solution is used for preparing the silicon template. The specific surface area of the mesoporous carbon is greater than 800 m 2 / g, and the pore size is less than 6 nm.

The utility model relates to alumina microsphere preparation technical field, concretely relates to a kind of preparation device of hundred-micron alumina microsphere, including feeding device, with the feeding pipe of feeding device connection, still including heating kettle, solvent cylinder being set in heating kettle, rotating shaft being rotationally arranged in solvent cylinder, rotating cavity being set in the lower end of rotating shaft and located in solvent cylinder, multiple micropore tubes being annularly arranged on rotating cavity, stirring paddle being set in the lower end of rotating cavity, servo motor being set in the upper end of heating kettle;The upper end of heating kettle is provided with the jack for the insertion of solvent cylinder, the rotating shaft is rotationally arranged in the upper side of heating kettle and is drivingly connected with servo motor, the upper end of rotating shaft is connected with feeding pipe, and the lower end is inserted in solvent cylinder.This device preparation hundred-micron alumina microsphere's specific surface area is large, and particle size is uniform, and equipment structure is not complex, easy to operate, and low in cost.

This invention discloses a magnetic solid-phase extraction method for detecting trace amounts of glucocorticoids in hydrophilic media, belonging to the field of sample pretreatment and chromatographic analysis technology. The method includes: adjusting the pH of a hydrophilic medium sample containing glucocorticoids and adding an ionic strength modifier to obtain a pretreated sample; mixing a magnetic covalent organic framework-based composite nanomaterial with the pretreated sample and performing oscillatory extraction under a dynamic gradient magnetic field to adsorb the glucocorticoids onto the material surface; separating the material adsorbed with glucocorticoids using an external magnetic field and discarding the supernatant; performing ultrasonic-assisted elution of the material using an elution solvent and collecting the eluent; and detecting the eluent using high-performance liquid chromatography-diode array detector (HPLC-DID) and calculating the glucocorticoid concentration based on a standard curve.

The invention discloses a method for preparing porous activated carbon based on pulse electrochemical activation, the porous activated carbon and application, and the method comprises the following steps: preparing a working electrode plate from carbon powder, and placing the working electrode plate in an electrolyte for pulse electrochemical square wave circulation treatment, wherein the electrolyte is an aqueous solution containing sulfuric acid, persulfate, sulfate and a cationic surfactant, stripping, cleaning and drying to obtain the porous activated carbon. According to the preparation method, the carbon powder is prepared into the working electrode plate, and the working electrode plate is subjected to pulse electrochemical square wave circulation treatment in the electrolyte containing the sulfuric acid, the persulfate, the sulfate and the cationic surface active agent, so that the porous activated carbon with large specific surface area, high electro-adsorption capacity and good conductivity can be prepared; when being used as a raw material for preparing a capacitive deionization electrode, the composite material shows good conductivity, high desalination capacity and high desalination rate, can be widely used for electro-adsorption desalination, and is high in use value and good in application prospect.

This invention belongs to the field of wet electronic chemicals technology, specifically relating to a method for preparing electronic-grade hydrogen peroxide. The method includes the following steps: adjusting the concentration of raw hydrogen peroxide, and then filtering it sequentially through a reverse osmosis membrane, a modified cation exchange resin, an anion exchange resin, and a mixed ion exchange resin to obtain electronic-grade hydrogen peroxide. The modified cation exchange resin used is modified based on conventional cation exchange resin through pore expansion and grafting, optimizing the spatial matching of pore structure and functional sites. This achieves passivation of metal ions, enhanced adsorption capacity, and improved oxidation resistance, as well as a deep synergistic effect of these three effects. Ultimately, it achieves the dual goals of efficient purification and stable operation of the resin in the hydrogen peroxide system. The resulting electronic-grade hydrogen peroxide can reduce the content of single impurity metal ions to below 5 ppt, meeting the requirements of SEMI G5 standards, and can be directly applied to high-end manufacturing fields such as semiconductor wafer cleaning.

A method for preparing a capacitive deionization anode for phosphate adsorption and desorption, and its application, belong to the field of inorganic phosphorus wastewater adsorption and enrichment. This invention aims to solve the problems of existing adsorption materials, such as low phosphate adsorption capacity, difficulty in reusing the adsorbent, or poor conductivity. Method: 1. Preparation of a PEDOT / YMOF-NH2 composite material; 2. Preparation of a capacitive deionization anode. Application: It is used for the adsorption and desorption of phosphates in phosphate-containing water. This invention is used for the preparation of a capacitive deionization anode for phosphate adsorption and desorption.

This invention belongs to the field of fluorescent detection materials technology, specifically disclosing an open-type colorimetric fluorescent covalent organic polymer and its preparation and application. The preparation includes the following steps: dissolving 4,4',4''-(1,3,5-triazine-2,4,6-triyl)tris(2,6-dimethylaniline) and trialdehyde-resorcinol in 1,4-dioxane; uniformly adding acetic acid via ultrasonication; degassing three times using a refrigerated pump followed by heating reaction; sequentially washing with tetrahydrofuran and dichloromethane using a Soxhlet washing method; drying; passing through a 200-mesh sieve; and dry grinding. This invention utilizes the aforementioned open-type colorimetric fluorescent covalent organic polymer and its preparation and application. This open-type colorimetric fluorescent covalent organic polymer reacts sensitively with aminourea and 3,5-dinitro-2-hydroxyphenylenehydrazine, and can be used in open-type fluorescent chemical sensors to reduce the influence of other impurities on the detection results, thereby improving the detection sensitivity.

The present application belongs to the technical field of biochar, and particularly relates to a high-activity acidolysis biochar, which is prepared by the following steps: S1, pretreating agricultural and livestock waste; S2, acidolysing the pretreated biomass with dilute acid to obtain acidolysed biomass; S3, placing the acidolysed biomass into a high-temperature furnace to perform carbonization under an oxygen-free condition, and using a step-by-step heating mode to obtain preliminary biochar; and S4, mixing the preliminary biochar with a copolymer solution to prepare the high-activity acidolysis biochar. In the present application, the sodium lignosulfonate-polyglutamic acid copolymer forms a stable connection with the biochar through chemical bonding, the porous surface of the biochar is uniformly covered with the copolymer to form a nanoscale film, the composite has stronger complexing, chelating and ion exchange capacity for heavy metal ions and other cations in the soil, and is helpful to reduce toxic substances in the soil and improve the soil environment.

The application discloses an electrode material based on MOF@COF / BC and application thereof in wastewater treatment and belongs to the technical field of wastewater treatment. The electrode material is prepared by the following method: NH2-MIL101(Fe), melamine and phthalocyanine molybdenum are dissolved in dimethyl sulfoxide, reaction is carried out at 160-200 DEG C for 10-14 h, the precipitate is collected after reaction, and washing, drying are carried out to prepare NH2-MIL101(Fe)@Mel-MoPc; the biochar and NH2-MIL101(Fe)@Mel-MoPc are mixed in deionized water, ultrasonic treatment is carried out for 8-12 min, stirring is carried out for 10-14 h, then the precipitate is collected by centrifugation, and washing, drying are carried out to prepare the electrode material. The application develops and designs a novel electrode material, which is used for electrocatalytic activation of peroxymonosulfate to degrade OFX wastewater, and the degradation efficiency of the OFX wastewater is greatly improved.

The application discloses a preparation method of polyurea porous material with flower cluster structure and application thereof. The material prepared by the application is a flower cluster porous polyurea material prepared by a self-assembly reaction in a mixed solvent of acetone and water, with hexamethylene diisocyanate as a reaction monomer. Nucleophilic addition reaction occurs between isocyanate groups and water molecules to generate a urethane intermediate, the intermediate rapidly decomposes to release CO2 gas and generate an amine group; the newly generated amine group immediately reacts with the remaining isocyanate groups in the system to form a polyurea oligomer, and then self-assembles into a flower cluster porous structure. The polyurea flower cluster structure has a high specific surface area, rich pores and controllable surface chemical properties, is an ideal material as an adsorbent, and can effectively capture dye molecules in a solution. The application solves the key technical problems of low adsorption capacity and poor selectivity of traditional adsorption materials in dye wastewater treatment.

The application relates to a composite type corrosion and scale inhibition water treatment agent, which is obtained by in-situ copolymerization of phosphono carboxylic acid copolymer after modification of nitrogen-doped carbon quantum dots on the surface of attapulgite as a carrier. The application has the beneficial effects that: the attapulgite is used as the carrier, can be used as a grafting bridge to load the carbon quantum dots on the surface and in-situ generate the phosphono carboxylic acid copolymer, and has a synergistic effect; the nitrogen-doped carbon quantum dots have rich amino, carboxyl and hydroxyl functional groups on the surface, make it difficult for calcium carbonate microcrystals to gather or interfere with the normal growth of the crystals to inhibit scale crystal generation, have high stability, are coated with zinc ions, improve the antibacterial property of the material, are modified on the surface of the attapulgite, have excellent adsorption performance, and can effectively remove organic matters, heavy metals and the like in water; the phosphono carboxylic acid copolymer is in-situ generated on the surface of the attapulgite, has a good compounding effect, has a good effect on corrosion inhibition, and has good corrosion inhibition performance.

This invention discloses a Cu2O / Cu3VO4 heterojunction catalyst, its preparation method, and its application in the photocatalytic reduction of CO2 to multi-carbon products, belonging to the field of catalyst materials technology. The preparation method includes: dissolving a copper source and a vanadium source in water to obtain a solution; mixing the solutions and adjusting the pH to 5-8 to obtain an initial solution; dispersing the solid from the initial solution after centrifugation in a mixture of ethylene glycol and water; and performing a hydrothermal reaction at 150-200℃ for 8-12 hours; washing and drying the reactants, and then calcining them at 500-600℃ for 2-5 hours under an inert atmosphere to obtain the Cu2O / Cu3VO4 heterojunction catalyst. In this catalyst, Cu2O and Cu3VO4 form a closely contacted heterojunction structure, enabling efficient separation of photogenerated electrons and holes under a built-in electric field and enhancing the absorption of visible light. Under visible light irradiation, this catalyst can reduce CO2 to multi-carbon products such as CO, CH4, C2H4, and C2H6, with an electron selectivity of up to 79% for the C2 products. The preparation process of this invention is simple and low-cost, and the resulting catalyst has broad application prospects in the field of photocatalytic CO2 reduction.

The utility model relates to an automatic slag discharging device for metallurgical slag, and aims to solve the problems that the slag cooling efficiency is low and the slag discharging process is not environment-friendly. The device comprises an L-shaped cooling pipe with a bent bottom, wherein the upper section of the L-shaped cooling pipe is communicated with a slag discharge port of the metallurgical furnace; the circulating cooling part is arranged on the cooling pipe and is used for cooling slag; the dispersing part comprises a rotating power mechanism, a rotating shaft and a dispersing plate, dispersing holes are densely distributed in the dispersing plate, the dispersing plate is located below the slag discharging opening, the rotating shaft is driven by the rotating power mechanism to rotate, slag is discharged from the dispersing holes under the action of gravity and centrifugal force and dispersed into particles, and rapid cooling and subsequent recycling treatment are facilitated; the blades are arranged on the rotating shaft and located above the slag discharging opening, and the blades rotate synchronously when the rotating shaft rotates; one end of the waste gas discharge pipe is communicated with the top of the cooling pipe, and the other end is connected with a waste gas treatment system for discharging and treating waste gas generated by slag cooling. According to the utility model, the slag cooling efficiency is improved, and the slag discharging process is more environment-friendly.

The invention relates to the technical field of adsorbent materials, and discloses a CoMn2O4 spinel adsorbent and a method for removing trivalent antimony in a water body by using the CoMn2O4 spinel adsorbent. The adsorbent is prepared by adopting a co-precipitation and low-temperature thermally induced crystallization synergetic green process: dissolving cobalt salt and manganese salt according to a stoichiometric ratio, dropwise adding a sodium hydroxide solution for co-precipitation, washing an obtained precursor, and drying at 80-120 DEG C under normal pressure for 12-48 hours to directly obtain the adsorbent. According to the method, the spinel material with low crystallinity, high specific surface area and rich surface hydroxyl is controllably synthesized by regulating and controlling the concentration of the precipitator and the drying condition, and the problems of active site loss and high energy consumption caused by traditional high-temperature calcination are avoided. When the composite material is used for treating wastewater containing trivalent antimony, antimony ions can be efficiently removed through the adsorption effect under the appropriate pH condition, excellent adsorption capacity is shown, the technology is simple, cost is low, safety is good, and an efficient and stable adsorption material and a feasible method are provided for water body antimony pollution treatment.

The application provides a synthesis method of a polymerization inhibitor 706 by using a sulfonated silicon dioxide catalyst, and the synthesis method comprises the following steps: dissolving a polyoxypropylene polyoxyethylene copolymer solution in water, adding concentrated hydrochloric acid and heating to 40 DEG C, adding tetraethyl orthosilicate to the solution, adding 3-mercapto propyl trimethoxysilane and 30wt.% hydrogen peroxide after stirring, continuing to stir, and after the reaction is completed, filtering the solution to obtain a filter cake and a filtrate, mixing the filtrate with the filter cake after treating the filtrate with activated carbon, and obtaining the sulfonated silicon dioxide catalyst through aging, washing, acidification and drying; the sulfonated silicon dioxide catalyst synthesized by the method has the advantages of simple synthesis method, high catalytic reaction activity and high reaction selectivity in the synthesis of the 706 polymerization inhibitor.

This invention discloses a method for preparing tin dioxide powder by freeze-drying to inhibit tin hydroxide agglomeration. The method involves adding a tin source solution (36-54 g / L) and a precipitant solution (5-30 g / L) at a mass ratio of 1:0.1-0.25 under constant temperature and magnetic stirring. The precipitant solution is then added dropwise to the tin source solution, reacting to form tin hydroxide colloid. After static aging, the colloid undergoes rapid cryogenic freezing to instantly freeze it into an ice state. The ice-state colloid is then subjected to low-temperature vacuum sublimation drying to obtain loose tin hydroxide dry powder. The dry powder is then calcined to obtain tin dioxide powder. This invention fundamentally eliminates the agglomeration of tin dioxide powder, resulting in tin hydroxide dry powder with an agglomeration rate of less than 10% and a purity of over 99.9%, providing a high-quality precursor for high-performance electronic-grade tin dioxide.

The application discloses a preparation method of a large-bore air-cooled diesel engine piston and specifically comprises the following steps: S1, modeling and dividing regions; S2, gradient printing; and S3, coating addition; and relates to the technical field of diesel engine pistons. The preparation method of the large-bore air-cooled diesel engine piston realizes the synergistic optimization of the overall performance of the piston through gradient printing of the piston, realizes the lightweight of the piston in cooperation with the honeycomb lattice structure, reduces the abrasion amount by using silicon carbide, improves the wear resistance of the top region, forms zirconium tri-aluminum nano precipitated phases by zirconium, refines the grains, forms a composite precipitated phase by using scandium, zirconium and aluminum, improves the high-temperature strength, constructs an efficient heat conduction network by using graphene nanosheets, improves the heat conductivity of the middle region, forms a three-dimensional network by using carbon nanotubes, improves the toughness of the skirt region, and has high interfacial bonding strength by spraying a wear-resistant and corrosion-resistant coating on the surface of the piston, reduces the friction, improves the service life of the piston and effectively reduces the maintenance cost.

The invention discloses a preparation method of organic acid modified biochar as well as a product and application of the organic acid modified biochar, reference and a method are provided for resource utilization of a large number of waste grape branches, salicylic acid modified grape-based biochar obtained by modifying salicylic acid with the concentration of 50 mg / L and 500 mg / L has excellent specific surface area; therefore, excellent adsorption performance is obtained. According to the invention, the grape-based biochar obtained by modification with 500 mg / L of salicylic acid can improve the salt resistance level of eggplants under the stress of 100 mmol / L of NaCl. The invention provides a new method for efficient resource utilization of the rape straws. The rape straw biochar obtained by modifying the 100 mg / L ferulic acid can obviously improve the fresh weight of lettuce.

This invention belongs to the field of membrane separation technology, specifically relating to a method for preparing a polytetrafluoroethylene (PTFE) composite membrane. The preparation method includes: (1) dissolving a spinning aid, a barium source, a titanium source, and a manganese source in a composite solvent, and then electrospinning to obtain precursor fibers; subsequently, blending the precursor fibers with a grain refiner, and heat-treating to obtain doped ferroelectric fiber bundles; (2) further polymerizing organic acids, inorganic acids, conductive fillers, and conductive polymers with monomers and oxidants to finally obtain a conductive polyaniline composite; (3) incorporating Mxene and the conductive polyaniline composite into an aqueous PTFE emulsion, and then further incorporating the doped ferroelectric fiber bundles and stirring to obtain a suspension; the suspension is then coated, post-treated, and kept warm to obtain a PTFE composite membrane. This invention improves the long-term fouling resistance of the PTFE membrane by doping the doped ferroelectric fiber bundles, the conductive polyaniline composite, Mxene, and PTFE.