50 results about "Ceric ammonium nitrate" patented technology

The invention discloses an intelligent control method for ceric ammonium nitrate precipitation process continuous production and application, and belongs to the field of intelligent production control, the intelligent control method comprises a hydrogen peroxide section intelligent control method and an ammonia water section intelligent control method, and the method comprises the steps that S1, a server receives V2; s2, a second potential sensor sends V2 ''; the server makes X2 = V2 '-V2, if the absolute value of X2 is within the threshold value, production continues, and if the absolute value of X2 is outside the threshold value, an alarm instruction is output; m1, the server receives the V3; and M2, the third potential sensor sends V3 ''to the server, the server makes X3 = V3''-V3, if the absolute value of X3 is within the threshold value, production continues, and if the absolute value of X3 is outside the threshold value, an alarm instruction is output. The reaction process is intelligently controlled, the process is adjusted in time, unqualified products are prevented from entering the next procedure, and stable quality of the whole procedure is guaranteed.

The invention relates to a polycarboxylic acid water reducer and a preparation method thereof, and the water reducer is prepared from the following raw materials: 45 to 55 percent of isopentenyl polyoxyethylene ether, 28 to 35 percent of acrylic acid, 1.5 to 2.5 percent of modifier, 0.3 to 0.5 percent of ammonium persulfate, 0.03 to 0.06 percent of ascorbic acid, 5 to 8 percent of hydroxyethyl methylacrylate, 0.15 to 0.25 percent of 2, 4-diphenyl-4-methyl-1-pentene and the balance of water. The modifier is prepared from the following raw materials: 1, 5-dichloronaphthalene, p-nitrostyrene, dimethyl sulfate, ceric ammonium nitrate and tetramethylpiperidine oxide. The polycarboxylate superplasticizer has excellent neat paste fluidity and fluidity retention capability, has low 1h time-dependent variable slump which is below 18mm and optimally 10mm when applied to concrete, has a water-reducing rate of more than 40% and a gas content of less than 3.8%, and also has more advantages in compressive strength ratio.

Provided are a metal-organic framework nanomaterial, a preparation method therefor, and a use thereof, belonging to the technical field of bionanomaterials, and resolving the technical problem of inhibiting atherosclerosis using biomimetic metal-organic framework nanoenzymes. The solution is: the components of the of the metal-organic framework nanomaterial and the ratio thereof are: metal ions Ce4+ and a ligand fumaric acid in a molar ratio of 1:5. The preparation method therefor is: measuring an FA regulator and water to prepare a mixed solution, then adding fumaric acid and cerium ammonium nitrate dropwise into the mixed solution, stirring at room temperature, centrifuging, repeatedly washing alternately with water and ethanol, and finally drying overnight in a vacuum oven. A simple, efficient and convenient method for synthesizing the metal-organic framework nanomaterial is provided. The synthesized metal-organic framework nanomaterial has excellent CEH-like enzyme activity and intrinsic antioxidant activity, and can be used to increase lipid efflux and reduce lipid uptake, and decrease ox-LDL-induced foam cell formation, thereby alleviating atherosclerosis.

The invention discloses a non-woven fabric made of Juncao fibers, and belongs to the technical field of textiles. The non-woven fabric made of the Juncao fibers is obtained by opening and mixing modified Juncao regenerated cellulose fibers, carding to form a net and needling and reinforcing; the modified pennisetum sinese regenerated cellulose fiber is prepared by the following steps: dipping dried pennisetum sinese pulp, squeezing, carrying out graft copolymerization on the squeezed dried pennisetum sinese pulp, 2-acrylamide-2-methylpropanesulfonic acid and benzaldehyde PEG acrylamide under the catalysis of ceric ammonium nitrate, dissolving, then adding chamomile essential oil microcapsules, reacting, and spinning. The chamomile essential oil microcapsule is prepared by the following steps: dispersing chamomile essential oil into a continuous phase containing an allyl monomer by an SPG membrane emulsification method to form a microemulsion, and preparing the chamomile essential oil microcapsule by combining an interfacial polymerization method; wherein the allyl monomer is prepared from methacrylic acid, methyl methacrylate, pentaerythritol tetraacrylate and N-(4-acetylphenyl) prop-2-acrylamide.

The invention discloses a UiO-66 (Ce) / ZnO composite photocatalyst as well as a preparation method and application thereof, and relates to the technical field of photocatalytic degradation of water pollution. The method specifically comprises the following steps: preparing zinc oxide by taking zinc acetate dihydrate, absolute ethyl alcohol and sodium hydroxide as raw materials; and dispersing the obtained zinc oxide in a DMF solution containing terephthalic acid, adding a ceric ammonium nitrate aqueous solution, and carrying out a heating reaction to synthesize the UiO-66 (Ce) / ZnO composite photocatalyst. According to the invention, ZnO and UiO-66 (Ce) are used for constructing a heterojunction for the first time, and the design not only widens the visible light response range, but also significantly improves the charge separation efficiency, thereby greatly enhancing the photocatalytic performance. The preparation process is simple and convenient, and the conditions are environment-friendly. The degradation rate of the obtained composite photocatalyst on tetracycline in waste water under visible light can reach 91.2%, the composite photocatalyst has good recoverability and reusability, a new scheme is provided for efficient degradation of organic pollutants, and the composite photocatalyst has remarkable advantages in the field of environmental protection.

The invention relates to the technical field of silicon carbide ceramic materials, and particularly discloses a preparation method of high-performance silicon carbide granulation powder. The method comprises the following steps: S1, preparing a composite adhesive system; s2, pre-dispersing the slurry; s3, ball milling dispersion; s4, mixing and size mixing; s5, spray drying; and S6, low-temperature activation. The adhesive is a ceric ammonium nitrate-ascorbic acid-dicyandiamide composite catalytic oxidation system, in the low-temperature activation stage, high-activity Ce < 3 + > generated by reaction of ceric ammonium nitrate and ascorbic acid efficiently catalyzes and cuts off polyvinyl alcohol molecular chains and promotes thorough decomposition of the polyvinyl alcohol molecular chains, dicyandiamide is decomposed to release gas to form a micro-channel, and a local atmosphere is created; the carbon residual rate is remarkably reduced to 0.06% or below, the apparent density is larger than or equal to 0.85 g / cm < 3 >, the porosity of a sintered body is smaller than or equal to 0.7%, and the technical problems of residual carbon control and uniform forming are solved.

The invention provides a cerium-based metal organic framework as well as a preparation method and application thereof, the cerium-based metal organic framework is obtained by uniformly mixing a cerium salt solution and a regulator, then carrying out a primary microwave heating reaction, then adding a ligand, carrying out a secondary microwave heating reaction, and then washing and drying, the cerium salt is ceric ammonium nitrate, and the ligand is cerium nitrate. The ligand is terephthalic acid, and the regulator is acetic acid. According to the method, the UiO-66 (Ce) with bionic Lewis acid sites is designed through microwave-assisted heating and by utilizing acetic acid to regulate the local chemical environment of the UiO-66 (Ce), so that the activity of hydrolase is greatly improved, a large number of oxygen vacancies can be induced, the activity of oxidase is improved, efficient degradation of glyphosate is realized, and the method has a wide application prospect in the aspects of glyphosate hydrolysis and detection.

The application provides a synthesis method of active piperidone alkaloid, and the active piperidone alkaloid is Dysidone A. The raw material piperidine is used as a substrate, and the substrate is reacted with p-methoxy benzyl chloride under the condition of N,N-diisopropylethylamine, so that the secondary amine is protected, and the side reaction of sodium hydride and hydrogen on the secondary amine is avoided. Then, the secondary amine is oxidized under the condition of iodine and iodobenzenediacetic acid. Next, the secondary amine is reacted with triethyl phosphine acetic acid ester to obtain an alpha, beta unsaturated ester. Then, the p-methoxy benzyl protection is removed by using ammonium cerium nitrate in a mild and efficient manner. Finally, the ester is reduced into an alcohol by using diisobutylaluminum hydride. The piperidone alkaloid or the like is obtained through five reaction steps. The synthesis process is simple, the raw material is cheap and easy to obtain, the cost is low, the reaction condition is relatively mild, the purity is high, and the method has good economic and social benefits.

This invention discloses a cerium-doped diatom-based silicon-carbon anode material, its preparation method, and its application, belonging to the technical field of lithium battery anode materials and their preparation. Using a diatom shell as a framework, a bio-doping method is employed. When the diatoms grow to the early logarithmic phase in a culture medium, cerium ammonium nitrate is added to the diatom culture medium for co-cultivation. The co-cultivated diatom shells are then calcined at high temperature to obtain the cerium-doped diatom-based silicon-carbon anode material. This invention employs a two-stage cultivation strategy, introducing cerium ammonium nitrate after the diatoms have reached the early logarithmic phase to avoid toxic inhibition during the growth-sensitive period. Simultaneously, it utilizes the efficient absorption and doping capabilities of diatoms during the active biomineralization phase, achieving a balance between high doping efficiency and structural integrity. This method utilizes the biomineralization capabilities of diatoms to achieve uniform elemental doping, resulting in a simple, low-cost, and environmentally friendly process; providing a new approach for the development of high-performance silicon-carbon anode materials.

The application discloses a synthesis method of 3,4-dimethyl-6-nitrophenol, which comprises the following steps: S1, 3,4-dimethylphenol and silica gel are added into an organic solvent, after the 3,4-dimethylphenol is dissolved, heating and concentration are carried out at 50-80 DEG C, until the organic solvent is evaporated, and the silica gel containing 3,4-dimethylphenol is obtained; S2, cerium ammonium nitrate and silica gel are added into an organic solvent, after the cerium ammonium nitrate is dissolved, heating and concentration are carried out at 50-80 DEG C, until the organic solvent is evaporated, and the silica gel containing cerium ammonium nitrate is obtained; S3, a silica gel column is taken, the silica gel containing 3,4-dimethylphenol and the silica gel containing cerium ammonium nitrate are added into the silica gel column, and then mixed solvents are used for column pressing; yellow oil is obtained after concentration; S4, the yellow oil is passed through a silica gel column, elution is carried out by using an eluent, and after concentration, the product 3,4-dimethyl-6-nitrophenol is obtained. The synthesis method of 3,4-dimethyl-6-nitrophenol improves the reaction yield, reduces the cost, and is green and environment-friendly.

The invention relates to the technical field of composite materials, in particular to a carbon fiber composite material bridge. The hard-soft modified spiral carbon fiber composite material is prepared from the following raw materials in parts by weight: 70 to 75 parts of bisphenol A epoxy resin, 15 to 25 parts of diethylenetriamine curing agent, 12 to 15 parts of hard-soft modified spiral carbon fiber, 6 to 8 parts of uvioresistant mixed powder, 3 to 5 parts of organic pigment dispersing agent and 5 to 7 parts of organic pigment. Spiral polyacrylonitrile fibers are prepared through a rope winding effect, then surface modification, high-temperature calcination and fulvic acid solution vacuum impregnation are conducted on tetrabutyl titanate and ammonium ceric nitrate, rigid-flexible modified spiral carbon fibers are prepared, the rigid-flexible modified spiral carbon fibers are added into a resin matrix to form a stress buffer layer, stress concentration is effectively relieved, meanwhile, a large number of hydrogen bonds and hydroxyl bonds are introduced, and the tensile strength of the composite material is improved. The bonding force between the fiber and a resin matrix is enhanced, meanwhile, strong locking can be formed between the spiral shape of the fiber and the matrix, the bending strength, the tensile strength and the impact strength of the carbon fiber composite material are greatly improved, and the mechanical property of the bridge is improved.

The invention discloses a copper-titanium etching solution, and relates to the technical field of microelectronic device manufacturing, and the copper-titanium etching solution comprises the following components by mass: 4.5-8.5% of ammonium persulfate; 1.5%-3.5% of urea peroxide; 1.0% to 2.0% of 1-hydroxybenzotriazole-5-carboxylic acid; 0.3% to 0.9% of 2-mercapto benzimidazole; 0.5% to 1.5% of sulfobutyl ether-beta-cyclodextrin; 0.8%-2.2% of L-aspartic acid-N, N-diacetic acid; 0.1% to 0.7% of iso-tridecanol polyoxyethylene ether; 0.05%-0.15% of ceric ammonium nitrate; 0.02% to 0.08% of sodium polyacrylate; and the balance of deionized water. According to the method, the matching problem of the etching rate is solved, the stability is improved, and substrate corrosion is avoided.

The invention provides a preparation method and application of a mesoporous material Ce / Ti-UiO-66-NH2, and the preparation method comprises the following steps: 1) mixing a certain amount of template agent, ceric ammonium nitrate, terephthalic acid, TMB, acetic acid and sodium perchlorate, dissolving in deionized water, and reacting to obtain Ce-UiO-66; (2) adding a certain amount of tetrabutyl titanate into a N, N-dimethylformamide solution containing Ce-UiO-66, and carrying out hydrothermal reaction, so as to obtain a Ce / Ti-UiO-66 solid; and (3) carrying out ultrasonic treatment on a certain amount of 2-aminoterephthalic acid and the Ce / Ti-UiO-66 solid in a methanol solution to obtain a Ce / Ti-UiO-66-NH2 solid. According to the method, simple and convenient synthesis of mesoporous Ce-UiO-66 can be achieved, the problem that in the prior art, a mesoporous Ce-UiO-66 synthesis method is difficult is solved, the metal titanium ion-doped and amino-loaded Ce / Ti-UiO-66-NH2 mesoporous material is prepared, and meanwhile, a new material is provided for the fields of photocatalysis and the like.

A preparation method of a rare earth-containing heterojunction catalyst material CeO2 / Sm-MOF comprises the following steps: mixing and dissolving samarium nitrate hexahydrate and H4TBAPy in a composite solvent to form a mixed solution, carrying out a hydrothermal reaction to obtain Sm-MOF, mixing and dissolving ceric ammonium nitrate and Sm-MOF in an aqueous solution of gamma-valerolactone, then adding H2O2 and triethanolamine to form a mixed solution, carrying out magnetic stirring at 45-55 DEG C for 2-3 h, and carrying out hydrothermal reaction to obtain the rare earth-containing heterojunction catalyst material CeO2 / Sm-MOF. And then carrying out hydrothermal reaction and roasting treatment. The thermal stability of Sm-MOF is improved, ceric ammonium nitrate is adopted as a Ce source, a two-step heat treatment process is combined, the binding force and distribution uniformity of CeO2 on the surface of Sm-MOF are effectively improved, the catalytic activity and cycle stability of CeO2 / Sm-MOF are improved, and the Sm-MOF / CeO2 composite material has excellent degradation efficiency on MB, RhB, ATZ, CIP and the like and has excellent cycle stability in the cycle process.

The present invention discloses a cerium-based metal-organic framework material containing defective sites, its preparation method, and application, and belongs to the field of phosphorus adsorption materials. The preparation method of the cerium-based metal-organic framework material containing defective sites of the present invention comprises the following steps: dissolving ammonium cerium nitrate and terephthalic acid in water and an organic solvent, respectively, and then mixing them, then mixing them with a monocarboxylic acid, and performing a solvothermal reaction to obtain the cerium-based metal-organic framework material containing defective sites. The preparation method of the present invention is simple and low-cost; the prepared cerium-based metal-organic framework material containing defective sites has the advantages of large phosphorus adsorption capacity, fast adsorption rate, high selectivity, and a wide pH range of application.

The application provides a preparation method of a heat insulation tile composite aerogel material, and belongs to the technical field of heat insulation tiles; the preparation method comprises the steps of preparing silane-treated basalt fibers, preparing modified silicon carbide and compounding and forming; in the step of preparing the silane-treated basalt fibers, the basalt fibers are placed in a pretreatment solution, kept at 74-77 DEG C for 1.4-1.6 h, then put into a cerium ammonium nitrate solution, immersed at 56-60 DEG C for 36-45 min, and then the immersed basalt fibers are obtained; the immersed basalt fibers are put into an ethanol solution, gamma-mercaptopropyltrimethoxysilane is added, and stirring is carried out at 70-75 DEG C for 3.0-4.0 h, and then the silane-treated basalt fibers are obtained; the heat insulation tile composite aerogel material prepared by the preparation method has good heat insulation performance and mechanical strength, good high-temperature resistance and excellent stability in a complex environment.

The application provides a low-acidity-high-stability etching solution and an etching method. In the cerium ammonium nitrate etching system, the low-acidity glacial acetic acid is used in the application, and the etching rate is still stable under the low-acidity condition, the etching effect is equivalent to or even better than that of the traditional high-acidity etching solution, and the disadvantages caused by the high acidity in the prior art are overcome.

The present invention belongs to the field of chemical engineering and discloses a method for preparing a novel covalent organic framework photoelectrocatalyst and the photoelectrocatalyst thereof. The method comprises reacting bromophenylporphyrin with phenylboronic acid to obtain an aldehyde group, thereby obtaining biphenylporphyrin (PP). Triphenylene (TC) reacts with ammonium cerium nitrate under a palladium-carbon catalyst to obtain an amino group, thereby obtaining diaminotriptycene (TAT). Under acidic conditions, the aldehyde group of the biphenylporphyrin (PP) and the amino group of the diaminotriptycene (TAT) react with each other to form a -C=N- bond, forming a stable Schiff base structure. This novel covalent organic framework photoelectrocatalyst can photoelectrocatalyze the production of urea from CO2 and nitrite, and exhibits advantages such as physical and chemical stability, good dispersibility, minimal environmental impact, and low cost.

The invention provides a method for circularly leaching uranium from cerium oxide through electrochemical catalysis, which belongs to the technical field of uranium mining and metallurgy and comprises the following steps: preparing a leaching solution containing ceric ammonium nitrate and sulfuric acid; adding the crushed uranium ore into the leaching solution, and leaching to obtain a leaching solution; adsorbing the leachate by using an ion exchange resin column; eluting the adsorbed ion exchange resin column to obtain uranium-containing eluent; precipitating, filtering and drying the uranium-containing eluent to obtain a uranium compound product; and adsorbing tail liquid obtained after leach liquor passes through an ion exchange resin column is electrolyzed to oxidize and regenerate Ce (III) into Ce (IV) for recycling. The method for cyclically leaching uranium through electrochemical catalysis of cerium oxide is efficient, environmentally friendly, sustainable, economical and feasible.

The invention belongs to the field of marine antifouling, and particularly relates to a composite material (CeO2-MOF / C) with halogenated peroxide mimic enzyme catalytic activity and preparation and application thereof. The specific method comprises the following steps: adding activated carbon black into a CeO2-MOF precursor, and calcining an obtained sample in a muffle furnace at 350 DEG C for 2 hours to prepare a CeO2-MOF / C composite material; wherein the precursor of the CeO2-MOF is 4, 4-diphenyldicarboxylic acid and ceric ammonium nitrate; the mass ratio of the precursor 4, 4-diphenyldicarboxylic acid to the ceric ammonium nitrate is 1: (1-1.5). The antifouling coating is constructed on the basis of cerium-based halogenated peroxide bionic enzyme, the prepared antifouling coating is used for antifouling application in real sea environments, and the real sea environments comprise a sea total immersion zone and a tidal range zone. The antifouling coating has no pollution to the marine environment, is green and environment-friendly, and has a wide application prospect in marine fouling protection.

A metal-organic framework (MOF) nanomaterial, its preparation method, and its application belong to the field of bionanomaterials technology. It addresses the technical problem of inhibiting atherosclerosis using biomimetic nanoenzymes derived from metal-organic frameworks. The solution involves the composition and proportion of the MOF nanomaterial as follows: [The remaining text appears to be incomplete and requires further context for accurate translation.] 4+ The molar ratio of ions to fumaric acid ligand is 5:1. The preparation method is as follows: a mixed solution is prepared by measuring FA regulator and water; then fumaric acid and cerium ammonium nitrate are added dropwise to the mixed solution; the mixture is stirred at room temperature and centrifuged; the solution is washed repeatedly with alternating water and ethanol; and finally, it is dried overnight in a vacuum oven. This invention provides a simple, efficient, and convenient method for synthesizing MOF nanomaterials. The synthesized MOF nanomaterials possess excellent CEH-like enzyme activity and intrinsic antioxidant activity, and can be applied to increase lipid efflux and reduce lipid uptake, decrease ox-LDL-induced foam cell formation, and thus alleviate atherosclerosis.

This invention belongs to the field of anti-corrosion coating technology and discloses a thin-layer high-barrier heavy-duty anti-corrosion coating and its preparation method. The coating comprises component A and component B, wherein component A is composed of fluorocarbon-polyurethane hybrid resin, glass flakes, cerium-doped carbon nitride, additives, and solvent, and component B is a curing agent and a diluent. The fluorocarbon-polyurethane hybrid resin is prepared by reacting fluorocarbon resin with a mixed isocyanate, which is a compound of aliphatic and aromatic isocyanates; the cerium-doped carbon nitride is obtained by calcining urea followed by secondary calcination with cerium ammonium nitrate. This invention, through resin hybrid design and synergistic use of functional fillers, achieves excellent acid and alkali corrosion resistance and long-term barrier effect under thin-layer conditions. The coating maintains surface integrity and stable adhesion even after immersion in corrosive media, and is easy to apply and low in cost, making it suitable for steel structure protection in harsh corrosive environments.

The invention discloses a silver monatomic antibacterial and antiviral material as well as a preparation method and application thereof, and belongs to the technical field of wood processing. The preparation method of the silver monatomic antibacterial and antiviral material comprises the following steps: firstly, preparing ZIF-8, then dissolving ceric ammonium nitrate in isopropanol, and adding titanium isopropylate to obtain a precursor solution; zIF-8 is added into the precursor solution, and TiO2 (at) ZIF-8 is prepared; and preparing a silver-ammonia solution, and adding the silver-ammonia solution into the TiO2 (at) ZIF-8 dispersion liquid to prepare the silver monatomic antibacterial and antiviral material (Ag SACs). Introduced monatomic silver has good dispersity and chemical stability, the problem of activity reduction caused by agglomeration of traditional nano-silver can be avoided while efficient antibacterial and antiviral performance is achieved, the environmental burden caused by silver agent release is reduced, and long-acting antibacterial performance is achieved.

The invention provides a guar gum-polyacrylamide grafted copolymer and a preparation method thereof.The method comprises the steps that guar gum is dissolved in deionized water, heating and stirring are conducted till the guar gum is completely dissolved, and high-purity nitrogen is introduced to remove oxygen; adding an acrylamide monomer for dissolving, firstly adding a ceric ammonium nitrate dilute nitric acid solution for pre-activation, cooling, and then adding a V-50 initiator solution; raising the temperature to carry out polymerization reaction under the protection of nitrogen; and after the reaction is completed, pouring a crude product into absolute ethyl alcohol to precipitate, filtering, washing, carrying out vacuum drying to constant weight, and finally grinding and sieving to obtain the powdery guar gum-polyacrylamide grafted copolymer. According to the preparation method, a composite initiating system is adopted, and a step-by-step pre-activation and low-temperature initiating process is adopted, so that the grafting efficiency and the grafting rate are remarkably improved, the limitation of a single initiator is overcome, the reaction is more controllable, and the generation of homopolymers is effectively reduced, so that the grafted copolymer with a more regular structure and more stable performance is obtained.

The invention discloses a super absorbent material CF-g-PAM and also discloses a method for preparing the super absorbent material by waste modification, under the condition of water bath heating, ceric ammonium nitrate is taken as an initiator, macromolecular carbon free radicals are firstly formed among cellulose acetate molecules as a main component of a filter tip CF, and then in the presence of N, N-methylene bisacrylamide, the macromolecular carbon free radicals are polymerized to form the super absorbent material CF-g-PAM. And carrying out free radical graft polymerization reaction with an acrylamide (AM) monomer to obtain the graft polymer CF-g-PAM with a high water absorption function. The method has the advantages of simple operation and mild reaction process. The resource utilization of common wastes in life is realized through simple free radical polymerization reaction, and the purpose of turning waste into wealth is achieved.

A preparation method includes 1) dispersing cellulose nanocrystal in water and adjusting pH to 7; 2) adding carboxylate to the aqueous dispersion of the step 1), and stirring until uniform; and 3) adding a monomer and a ceric ammonium nitrate initiator to the system of the step 2), reacting for 0.5-3 h to obtain a precipitate, and subjecting the precipitate to suction filtration, washing, and drying to obtain the cellulose nanocrystal powder. By adding a small amount of carboxylate into a cellulose nanocrystal graft polymer modification system initiated by ceric ammonium nitrate, hydrolysis of cerium ions can be inhibited through complexation of the carboxylate to the cerium ions which play an initiating role in ceric ammonium nitrate, so that ceric ammonium nitrate can initiate the polymerization reaction under acid-free conditions, thereby achieving polymerization of polyvinyl acetate monomer on the surface of cellulose nanocrystals.

The application relates to the technical field of lead-free tin paste, in particular to low-residue lead-free tin paste and a preparation method thereof. The raw materials of the low-residue lead-free tin paste include, by mass fraction, 100 parts of tin powder, 1-2 parts of nickel powder, 0.1-0.5 parts of gallium powder, 1-2 parts of bismuth powder, 0.1-1 parts of copper powder, 0.01-0.1 parts of silver powder, 0.01-0.1 parts of nanocellulose aerogel, 1-2 parts of 2-phenylimidazoline, 0.01-0.1 parts of cerium ammonium nitrate, 0.01-0.1 parts of Gemini quaternary ammonium salt, 0.01-0.1 parts of acrylic anhydride, 0.01-0.1 parts of potassium nitrate, 1-5 parts of hydrogenated rosin pentaerythritol ester and 1-10 parts of a soldering flux. The application effectively realizes low residue under the premise of guaranteeing welding quality, the tin paste is not only excellent in storage stability and good in process adaptability, but also high in solder joint strength and low in solder wire defect rate, and is particularly suitable for high-end electronic packaging fields such as new energy automobile power modules.

This invention belongs to the field of catalytic denitrification technology, specifically relating to a manganese-cobalt composite oxide-supported CeO2 denitrification catalyst and its preparation method. The invention first dissolves manganese and cobalt salts in a mixed solution of ethylene glycol and N-methylpyrrolidone, and then performs a solvothermal reaction to obtain a manganese-cobalt composite oxide precursor. Next, the obtained manganese-cobalt composite oxide precursor is dissolved in water with cerium ammonium nitrate, and then calcined at high temperature to obtain a CeO2-supported manganese-cobalt composite oxide denitrification catalyst. Compared with existing technologies, the CeO2-supported manganese-cobalt composite oxide material synthesized in this invention has better crystallinity, dispersibility, and thermal stability. As a selective catalytic reduction (SCR) denitrification catalyst, it has the advantages of high low-temperature denitrification activity and a wide activity temperature window. Furthermore, the synthesis route is simple and easy to implement, suitable for large-scale production.

The invention discloses a selective etching solution for metal molybdenum, which comprises the following components in percentage by mass: 7%-15% of electronic-grade phosphoric acid, 38%-49.5% of electronic-grade acetic acid, 3.0%-5.5% of electronic-grade nitric acid, 15%-25% of acetonitrile, 0.5%-2.0% of ceric ammonium nitrate, 0.5%-3.0% of indium gallium zinc oxide (IGZO) etching inhibitor and the balance of deionized water. When the etching liquid is used for etching operation, on the premise that the etching rate of the IGZO is smaller than or equal to 0.05 nm / min, efficient removal of a metal molybdenum deposition layer can be achieved, no metal molybdenum and oxide residues of the metal molybdenum exist after etching, and etching of the metal molybdenum and the IGZO has a high selection ratio.

The invention belongs to the technical field of nano materials, and particularly relates to a nano cellulose composite material as well as a preparation method and application thereof. The preparation method of the nanofiber composite material comprises the following steps: uniformly mixing carboxylated nanocellulose with an ammonium ceric nitrate aqueous solution, incubating for 10-16 hours while stirring, centrifuging and collecting a precipitate, dispersing the precipitate into an N, N-dimethylformamide solution, and heating for 20-40 minutes at 80-100 DEG C to obtain the nanofiber composite material, according to the carboxylated cellulose prepared by the preparation method disclosed by the invention, antioxidant active ingredients are uniformly distributed on the surface of the carboxylated cellulose, and agglomeration of the carboxylated cellulose in a physiological environment is effectively prevented, so that lasting and stable exertion of the antioxidant activity of the carboxylated cellulose is ensured; therefore, the invention provides application of carboxylated cellulose in preparation of an antioxidant material.