613 results about "Tungstic acid" patented technology

The invention belongs to the technical field of superfine tungsten powder, and particularly relates to superfine tungsten powder and a preparation method thereof.The preparation method includes the steps that an ammonium tungstate solution, hydrochloric acid and carbon black serve as raw materials to prepare a mixture of tungstic acid and a carbon precursor; calcining the tungstic acid and carbon precursor mixture in a nitrogen atmosphere to obtain a tungsten oxide and carbon mixture; a tungsten oxide and carbon mixture is calcined in an argon atmosphere, the argon atmosphere is kept for natural cooling, the superfine tungsten powder is obtained, the superfine tungsten powder is uniform in dispersion, complete in grain development, smooth in surface, free of pores and complex in morphology, the crystal structure of the superfine tungsten powder is a body-centered cube, the average particle size is smaller than or equal to 0.7 micrometer, and the specific surface area is smaller than or equal to 1.0 m < 2 > / g.

The invention relates to the field of shielding materials, and provides lead-free rubber with ionizing radiation shielding performance and a preparation method thereof, and the lead-free rubber is mainly prepared from barium titanate / boron nitride composite filler, barium tungstate / boron carbide composite filler, tungsten powder, bismuth powder, a rubber matrix and an auxiliary agent according to a proportion. The barium titanate particles are uniformly loaded on the surface of the flaky boron nitride, so that the gamma ray and X ray shielding performance is improved, and meanwhile, the boron nitride provides excellent neutron shielding capability; barium tungstate particles are loaded on the surfaces of the boron carbide nanowires to form a multi-scale shielding network, and the shielding effect of neutrons and ionizing radiation is remarkably enhanced. The rubber matrix endows the material with excellent flexibility and mechanical properties. By scientifically optimizing the component proportion and the preparation process, the problems that a traditional high-density shielding material is prone to agglomeration, poor in flexibility and the like are solved, and the material shows excellent performance in the fields of gamma ray, X ray and neutron shielding and is suitable for the fields of nuclear energy, medical protection, industrial radiation protection and the like.

The invention discloses a self-adaptive light-dimming temperature-control polyurethane protective film and a preparation method thereof, and relates to the technical field of high polymer materials. When the self-adaptive light-dimming temperature-control polyurethane protective film is prepared, castor oil reacts with sulfhydrylated thiosemicarbazone to prepare modified castor oil; the preparation method comprises the following steps: carrying out ring opening polymerization on flame-retardant cyclotetrasiloxane and tetramethyl cyclotetrasiloxane to prepare a siloxane oligomer; enabling vanadium pentoxide, oxalic acid and tungstic acid to react to prepare tungsten-doped vanadium dioxide; the preparation method comprises the following steps: carrying out a reaction on tungsten-doped vanadium dioxide and allyltriethoxysilane to prepare modified vanadium dioxide; uniformly mixing castor oil, modified castor oil, siloxane oligomer, isophorone diisocyanate and copper chloride, pouring the mixture into a mold, and performing curing molding, so as to obtain the self-adaptive light-dimming temperature-control polyurethane protective film. The self-adaptive light-dimming temperature-control polyurethane protective film prepared by the invention has excellent flame retardance, tensile strength and self-adaptive light-dimming temperature-control performance.

The present invention provides an electrochromic fabric and a preparation method thereof. The conductive fabric is treated to make its surface rich in active functional groups; oxalic acid and sodium tungstate solution are mixed, hydrochloric acid is added to adjust the pH, and then n-butanol is added to obtain a precursor solution. The fabric is placed in the precursor solution for high-temperature reaction to obtain the electrochromic fabric. By pre-treating the fabric, the number of functional groups on the fabric surface is increased, and adjusting the pH enhances the binding force between WO3 and the fabric; n-butanol ensures the stable formation of tungsten trioxide, promotes the interaction between oxalic acid and the functional groups on the fabric surface, improves the interfacial interaction force between the WO3 crystal nucleus and the fabric, and at the same time affects the crystal nucleus growth direction, forming a nanorod-like or three-dimensional microsphere structure, and improving the electrochromic performance. Through the synergistic cooperation of each process and related parameters, the electrochromic fabric of the present invention has obvious color change, good cycle stability and high mechanical properties; and the process is simple, the cost is low, and it is suitable for industrial mass production.

The invention discloses a lubricating oil preparation method, which comprises: contacting a raw material containing waste rubber with a catalyst in a closed container in a hydrogen atmosphere, and carrying out a catalytic cracking reaction to obtain a lubricating oil-containing product, the catalyst comprises a carrier, an acidic component and an active component loaded on the surface of the carrier, the active component is selected from at least one of a ruthenium elementary substance, a rhodium elementary substance, a platinum elementary substance, a palladium elementary substance, an iridium elementary substance and a nickel elementary substance; the acidic component is selected from at least one of silicotungstic acid, ammonium metatungstate, phosphotungstic acid and tungstic acid. The invention discloses a new path for preparing the lubricating oil by utilizing the waste rubber through a carbon = carbon hydrogenation and carbon-carbon bond breakage strategy under a relatively mild condition. According to the path, new application of waste rubber catalytic conversion is developed through C = C hydrogenation and C-C bond fracture strategies, and a new method for synthesizing lubricating oil with important application value is provided.

The invention provides application of a silver-bismuth tungstate catalyst in preparation of methanol from light-driven CO2, and belongs to the technical field of CO2 conversion and reduction. Bismuth tungstate nanosheets, silver salt and water are mixed, the size of silver particles is controlled by adjusting the pH value, the silver-bismuth tungstate catalyst is obtained, and the size of the silver particles is 20-50 nm; silver is evenly distributed on the surface of bismuth tungstate, the obtained silver-bismuth tungstate catalyst is large in specific surface area and high in light response capacity, the silver-bismuth tungstate catalyst can generate a large number of high-energy hot electrons during illumination, in-situ photo-thermal conversion is achieved, no external heat source is needed for heat supply, the photo-thermal effect is enhanced, CO2 conversion is promoted, and the methanol yield is increased.

The invention belongs to the technical field of electrode materials and nuclide recovery, and discloses a W18O49 / graphene / phosphorylation / amidoximation electrode material and preparation and application thereof. The preparation method comprises the following steps: dispersing ammonium tungstate and graphene in a trihydroxymethyl aminomethane solution, and heating and stirring for reaction to obtain a mixed solution; then adding dopamine hydrochloride, ethanol and ammonia water, stirring and reacting, and washing and drying a product to obtain a precursor; and carbonizing the obtained precursor in an inert atmosphere at the temperature of 600-900 DEG C to obtain a W18O49 / graphene material, then dispersing the W18O49 / graphene material in a hydroxylamine hydrochloride solution and / or a phytic acid solution for stirring reaction, and washing and drying the product to obtain the W18O49 / graphene / phosphorylation / amidoximation electrode material. The selective recovery efficiency of the obtained electrode material on uranyl ions can reach 95% or above, and the electrode material has wide application prospects in the field of nuclide uranium recovery.

The invention relates to the technical field of hazardous waste utilization, in particular to a comprehensive utilization method of a waste catalyst. The method specifically comprises the following steps: sequentially carrying out oxidizing roasting, wet ball milling and pressure leaching on the waste catalyst to obtain a first leaching solution and leaching residues; the first leachate is extracted in a multi-stage counter-current extraction mode, molybdenum and tungsten in the first leachate are extracted, and back extraction is conducted to obtain back extraction liquid containing molybdenum and tungsten; the strip liquor is subjected to standing deoiling, evaporation concentration and multi-stage counter-current extraction vanadium removal in sequence, and raffinate and vanadium-containing strip liquor are obtained; the raffinate mainly contains molybdate radicals and tungstate radicals; determining a separation mode according to different molar ratios of molybdenum and tungsten; carrying out acid leaching on the leaching residues by utilizing a sulfuric acid solution at normal temperature and normal pressure to obtain a second leaching solution; and a cobalt extraction agent and a nickel extraction agent are respectively used for extraction, and a cobalt sulfate product and a nickel sulfate product are obtained after reverse extraction and evaporative crystallization. According to the method provided by the invention, metal resources such as vanadium, tungsten, cobalt, molybdenum and nickel in the waste catalyst can be recycled.

The invention discloses a high-sulfur-tolerance SCR honeycomb denitration catalyst and a preparation method thereof, and belongs to the technical field of industrial catalysts.The preparation method comprises the steps that S1, anatase type TiO2 and NH4HCO3 are mixed for pulping, pre-drying and calcination are conducted after extrusion forming, and a green body is formed; s2, carrying out nitric acid treatment on the green body, dipping the green body in a mixed solution of copper nitrate hydrate and cerium nitrate hydrate, and carrying out vacuum dipping, microwave drying and two-stage calcination to obtain a desulfurization carrier; s3, depositing an ammonium metatungstate precursor on the surface of the desulfurization carrier through CVD, and calcining to form a WO3 transition layer; and S4, dipping the transition layer in an acid solution containing NH4VO3 and ammonium metatungstate, and calcining after ultrasonic treatment to obtain a finished product. According to the method, the pore structure of the carrier is optimized through chambering treatment, and the stability and denitration efficiency of the catalyst in high-sulfur flue gas are remarkably improved by combining a multistage sulfur-resistant mechanism that the desulfurization layer preferentially captures SO2, the WO3 transition layer obstructs sulfur penetration and the denitration layer is protected by active sites.

The invention discloses a method for preparing a core-shell structure phase hydrorefining catalyst, comprising the following contents: (1) gelling, aging and filtering a first precipitant, a sodium molybdate solution and a solution containing Ni and Si to obtain a filter cake of a first slurry, and then treating it with a mixed aqueous solution of aluminum salt and organic alcohol to obtain a mixed slurry; (2) adding a Ni-containing solution, a sodium tungstate solution, a second precipitant and the mixed slurry obtained in step (1) to a reactor containing water and an oily liquid to gel and age them to generate a second slurry; (3) filtering, drying and molding the slurry to obtain a molded product; (4) soaking the molded product in an organic acid solution, and desalting the soaked molded product to obtain a catalyst. The preparation process of the method is clean and pollution-free, and the prepared catalyst has a core-shell structure, a large pore volume and a large pore size, and is used in processes such as distillate hydrodesulfurization and denitrogenation, and has high hydrodesulfurization and hydrodenitrogenation reaction performance.

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a manganese ferrite / bismuth tungstate heterojunction photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: 1) dissolving sodium tungstate dihydrate, bismuth nitrate pentahydrate and hexadecyl trimethyl ammonium bromide in deionized water, and obtaining bismuth tungstate by using a hydrothermal method; 2) dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in water, then adding a sodium hydroxide solution, and obtaining manganese ferrite by using a hydrothermal method; and 3) dissolving bismuth tungstate and manganese ferrite into a sodium hydroxide solution, stirring, and drying to obtain the manganese ferrite / bismuth tungstate heterojunction photocatalyst. The formation of the heterojunction can greatly improve the activity of the manganese ferrite / bismuth tungstate in photocatalytic reduction of carbon dioxide.

The invention provides a rapid preparation method of tungsten trioxide, which specifically comprises the following steps: step 1, weighing crude tungstic acid, dissolving in ammonia water, heating and stirring to obtain an ammonium tungstate solution; step 2, slowly dropwise adding the ammonium tungstate solution in the step 1 into a poor solvent to obtain an ammonium paratungstate suspension, and step 3, filtering the ammonium paratungstate suspension in the step 2 to obtain an ammonium paratungstate filter cake, and leaching the ammonium paratungstate filter cake with the poor solvent; 4, the ammonium paratungstate filter cake in the step 3 is placed in a drying oven to be dried; and (5) roasting the ammonium paratungstate filter cake in the step (4) at high temperature to obtain a faint yellow irregular flaky tungsten trioxide product. According to the preparation method, a mixed solvent crystallization and high-temperature roasting two-step process is adopted, the solubility of ammonium tungstate in water is reduced by adding a poor solvent, so that an ammonium tungstate solution rapidly reaches a saturated state and is separated out, the crystallization process of ammonium paratungstate is accelerated, and the preparation speed and the crystallization rate of a tungsten trioxide product are high.

The invention belongs to the technical field of building glass and coating materials thereof, and discloses a one-step chemical synthesis method of W-VO2 (M) nano-particles and application of the W-VO2 (M) nano-particles in thermochromic smart windows.The method comprises the steps that firstly, ammonium metavanadate, hydrazine hydrate and ammonium metatungstate serve as raw materials, tungsten-doped M-phase vanadium dioxide nano-particles are chemically synthesized through a one-step hydrothermal method, and the tungsten-doped M-phase vanadium dioxide nano-particles are prepared; the obtained W-VO2 (M) nanoparticles are high in crystallinity, small in particle size (10-40nm), high in purity and low in phase change temperature; then, by taking a polyvinylpyrrolidone material as a parent material, uniformly distributing the W-VO2 (M) nanoparticles in PVP (Polyvinyl Pyrrolidone) to form a uniformly dispersed thin film; according to the application of the W-VO2 (M) nanoparticles in the thermochromic intelligent window, not only can high visible light transmittance be obtained, but also the solar energy regulation and control capability of the W-VO2 (M) nanoparticles can be improved, and the application of the W-VO2 (M) nanoparticles in the fields of the thermochromic intelligent window and radiation refrigeration is further promoted.

The invention belongs to the technical field of tungsten metallurgy, and particularly relates to a method for reducing the water content of tungstic acid, which comprises the following steps: S1, heating a container filled with a sodium tungstate solution in a water bath kettle, stirring the sodium tungstate solution, and adding ethanol; s2, adding hydrochloric acid into the sodium tungstate solution added with the ethanol, adjusting the pH value of the solution, monitoring in real time in the reaction process to ensure that the pH value of the solution is stable, stopping heating to naturally cool the solution to an aging temperature for constant-temperature aging, and then filtering and washing; and S3, drying to obtain tungstic acid. The water content of the tungstic acid obtained after filtering and washing is less than or equal to 30wt%.

The invention relates to the technical field of all-vanadium redox flow battery electrodes, and discloses a preparation method of an iron-tungsten loaded graphite felt for a vanadium redox flow battery, which comprises the following steps: dissolving a tungstic acid compound, ferrite and a surfactant in water to prepare an electrodeposition solution; the preparation method comprises the following steps: immersing a graphite felt in an electro-deposition liquid, carrying out vacuum standing, taking out the graphite felt as a working electrode, carrying out electrochemical deposition, cleaning and drying, immersing the obtained metal-loaded graphite felt in an aqueous solution containing benzene peroxide series and phenylenediamine substances, carrying out hydrothermal treatment, cleaning and drying, and carrying out high-temperature treatment on the obtained precursor graphite felt to obtain the metal-loaded graphite composite material. And obtaining the iron-tungsten loaded graphite felt for the vanadium battery. By loading iron and tungsten on the graphite felt, the catalytic activity site and conductivity of the graphite felt can be effectively improved, the benzene peroxide series can partially oxidize tungsten, generated carboxylic acid and phenylenediamine substances form a condensate, and the catalytic activity and stability of the graphite felt fiber are further improved.

This invention relates to a method of reducing abnormal combustion events in a hydrogen fueled internal combustion engine (HICE) during operation of the engine. The method includes the steps of: a) providing to the HICE a lubricating oil composition including or resulting from the admixing of: i) a base oil having a KV100 of less than or equal to 12 cSt and included at greater than 50 wt.% of the composition and comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof; ii) at least one organoammonium tungstate compound included at a treat level to deliver between 10 to 5000 ppm by weight of total tungsten to the composition; iii) at least one overbased metal containing detergent with a Total Base Number (KOH / g) greater than or equal to 9 and less than or equal to 500 and included at a treat level to deliver between 100 to 5000 ppm by weight of total metal and between 0.15 wt. % to 8.0 wt. % of total soap to the composition; and iv) the lubricating oil composition having a total sulfated ash of less than or equal to 2.5 wt.%, a total phosphorous level of less than or equal to 0.120 wt.%, and a SAE viscosity grade of 25W-X, 20W-X, 15W-X, 10W-X, 5W-X or 0W-X, where X represents any one of 8, 12, 16, 20, 30, 40, 50 or 60; b) providing a fuel comprising hydrogen to the HICE; and c) combusting the fuel in the HICE. Also provided are lubricating oil compositions and concentrates for use in a HICE to reduce the propensity for abnormal combustion events.

The invention relates to a WO-NiSe CeO2 self-supporting heterostructure catalyst and a preparation method thereof. The preparation method comprises the following steps: preparing Ni LDH at CeO2 on foamed nickel through a hydrothermal method, then realizing high-valence tungstate radical doping through impregnation exchange, and finally carrying out secondary hydrothermal selenylation to obtain a porous nanosheet heterojunction material with CeO2 nanoparticles attached to the surface, namely WO-NiSe at CeO2. The introduction of high-valence tungstate radicals and the coupling of CeO2 form a strong electron coupling interface on the surface of NiSe, and HER / OER charge transfer is accelerated. And according to a hard-soft acid-base (HSAB) theory, the high-valence metal serving as a relatively hard Lewis acid shows higher selectivity on OH <-> than Cl <->, so that accumulation of Cl <-> on the surface of the catalyst can be inhibited, the catalytic activity is remarkably improved, and the corrosion-resistant life is remarkably prolonged. According to the strategy, a new'activity-stability-cost 'ternary equilibrium normal form with the advantages of low overpotential, long-period stability and salt corrosion resistance is provided for seawater electrolytic hydrogen production, and the theoretical value and the industrialization potential are both achieved.

The invention discloses a regeneration method of a marine vanadium-titanium denitration catalyst. The regeneration method comprises the following steps: (1) immersing a deactivated catalyst into a diluent of a special cleaning agent for grease for cleaning; (2) carrying out spray cleaning on the catalyst cleaned in the step (1), wherein a spray cleaning solution is water; (3) carrying out acid chemical cleaning on the catalyst cleaned in the step (2) to remove alkali metal harmful substances such as sodium, potassium and the like attached to the catalyst; (4) washing the catalyst cleaned in the step (3) with water; (5) drying the catalyst cleaned in the step (4); (6) the catalyst dried in the step (5) is soaked in an active solution for active reimplantation, and the active solution mainly comprises ammonium paratungstate and ammonium molybdate and further comprises one of ammonium metavanadate and vanadyl oxalate; and (7) draining the catalyst subjected to activity reimplantation in the step (6), and putting the catalyst into a calcining furnace for activity activation. According to the method disclosed by the invention, more than 98% of pollutants such as grease, ash, alkali metal and sulfate can be removed, and the use temperature after regeneration is reduced by 20-60 DEG C compared with the original use temperature.

The invention discloses a separation and purification method of vanadium-containing tungstate. The method comprises the following steps: providing a vanadium-containing tungstate aqueous solution; providing an extraction liquid, wherein the extraction liquid comprises a sulfuric acid type quaternary ammonium salt extraction agent, a modifier and an organic solvent; mixing the vanadium-containing tungstate aqueous solution with the extraction liquid, and performing first extraction to obtain a first extraction phase and a first raffinate phase; providing strip liquor, wherein the strip liquor comprises alkali metal sulfate and alkali metal hydroxide; mixing the first extraction phase with the strip liquor, and carrying out first reverse extraction to obtain an alkali metal vanadate solution; and carrying out the same extraction and reverse extraction method on the first raffinate phase to obtain an alkali metal tungstate radical solution, thereby realizing respective separation and purification of vanadate radicals and tungstate radicals.

The invention discloses a molybdenum-manganese composite metal oxide catalyst for efficiently purifying NO2 as well as a preparation method and application of the molybdenum-manganese composite metal oxide catalyst, and relates to the technical field of catalysts. According to the technical scheme, ammonium metavanadate, oxalic acid, ammonium metatungstate and titanium dioxide are mixed to prepare turbid liquid, the turbid liquid is heated in a water bath, stirred and evaporated until the turbid liquid is solidified, and a vanadium-tungsten-titanium composite oxide precursor is prepared after drying and calcination; the preparation method comprises the following steps: dissolving manganese salt and ammonium molybdate in formamide, carrying out ultrasonic treatment to form a uniform solution, mixing the solution with the vanadium-tungsten-titanium composite oxide precursor powder, carrying out heat preservation and stirring, and finally drying and calcining to prepare the molybdenum-manganese metal diatom vanadium-tungsten-titanium composite oxide catalyst. The molybdenum-manganese composite metal oxide catalyst provided by the invention can realize efficient catalytic reduction of NO2 to form N2 and H2O at a low temperature of 200 DEG C, and the conversion rate of NO2 in a temperature interval of 200-400 DEG C is higher than 85%; and meanwhile, the N2 selectivity is kept close to that of a V2O5-WO3 / TiO2 catalyst.

The invention discloses a method for recovering valuable metals tungsten and tin from hazardous waste tungsten slag, and aims to solve the problems that the existing method for recovering the valuable metals from the tungsten slag needs higher temperature and the recovery rate of the valuable metals tungsten and tin needs to be improved. The recovery method comprises the following steps: S1, uniformly stirring and mixing tungsten slag powder with a reducing agent and a vulcanizing agent A; s2, the slag agent mixture in the S1 is placed in a tubular furnace to be subjected to high-temperature reduction treatment; s3, carrying out sulfuric acid leaching treatment on the furnace slag; s4, the acid leaching residues serve as a vulcanizing agent B, and high-temperature reduction treatment and sulfuric acid leaching treatment are repeated for multiple times; and S5, stirring the tungsten-enriched sulfide slag and sodium hydroxide, roasting, performing water leaching on a product to obtain a sodium tungstate solution, and finally performing evaporative crystallization. The valuable metal tin in the hazardous waste tungsten slag is extracted through high-temperature vulcanization reduction. Tin is recovered through sulfuration reduction reaction, sulfide generated by lead and arsenic oxides is separated from scheelite slag and enters smoke dust, iron and manganese oxides are subjected to sulfuration reduction reaction and enter a slag system, and harmless treatment of hazardous wastes is achieved.

The invention belongs to the technical field of optical glass. The invention relates to an electrochromic glass device, in particular to a preparation method of the electrochromic glass device. The preparation method comprises the following specific preparation steps: cleaning the surface of a glass substrate, and depositing an indium tin oxide transparent conductive layer on the surface of the glass substrate by adopting magnetron sputtering; the preparation method comprises the following steps: by taking nano spherical silicon dioxide as a template, dispersing the nano spherical silicon dioxide in an ethanol solution, then adding a sodium tungstate solution, then adjusting the pH value to 2-3, carrying out a stirring reaction, and then cleaning with a sodium hydroxide solution to remove the template so as to obtain a hollow spherical precursor dispersion liquid; coating the hollow spherical precursor dispersion liquid on the surface of the transparent conductive layer in a spin coating mode, drying and annealing; preparing a liquid electrolyte: taking propylene carbonate as a solvent, and taking lithium perchlorate as an electrolyte lithium salt; niO is deposited on the surface of the WO3 electrochromic layer to serve as a counter electrode through magnetron sputtering; epoxy resin is adopted to package the edge, after liquid electrolyte is injected, internal residual bubbles are removed through hot pressing, and the product is obtained.

The invention relates to the technical field of oral products, and particularly discloses a manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening and a preparation method thereof. The preparation method comprises the following steps: preparing manganese tungstate nano-particles, dispersing tungsten hexacarbonyl and a surfactant in a first organic solvent, adding an oleic acid / oleylamine ligand pair under a first reaction condition, and then carrying out stirring reaction, cooling, centrifuging, washing and drying under a second reaction condition to prepare the manganese tungstate nano-particles. And preparing a manganese tungstate nanoparticle / polyethylene glycol composite material, dispersing the manganese tungstate nanoparticles and a polyethylene glycol derivative in a second organic solvent, uniformly stirring, and carrying out nitrogen drying to prepare the manganese tungstate nanoparticle / polyethylene glycol composite material. The manganese tungstate nanoparticle / polyethylene glycol composite material is dissolved in artificial saliva, a hydrogen peroxide solution is added and mixed, and the manganese tungstate nanoparticle / hydrogen peroxide composition for tooth whitening is prepared.

The invention discloses a tungsten trioxide electrochromic film for multi-tungsten oxygen cluster induced in-situ crystallization as well as a preparation method and application of the tungsten trioxide electrochromic film. The preparation method comprises the following steps: S1, adding hydrochloric acid into a sodium tungstate dihydrate aqueous solution to obtain a precipitate; washing the precipitate until the pH value of the supernate is greater than 3, and then drying the precipitate to obtain hydrated tungstic acid powder; dissolving the hydrated tungstic acid powder in a hydrogen peroxide solution to obtain a peroxy tungstic acid solution; s2, heating, evaporating and concentrating the peroxy tungstic acid solution to obtain a precursor solution containing multi-tungsten-oxygen clusters; and transferring the precursor solution containing the multi-tungsten-oxygen cluster to a substrate by adopting a film coating process, and annealing to obtain the tungsten trioxide electrochromic film with multi-tungsten-oxygen cluster induced in-situ crystallization, a matrix of the tungsten trioxide electrochromic film for multi-tungsten-oxygen cluster induced in-situ crystallization is amorphous tungsten trioxide, and hexagonal-phase tungsten trioxide nanocrystals are dispersed and distributed in the amorphous tungsten trioxide.

The invention discloses a preparation method of nano tungsten-nickel-iron composite powder, which comprises the following steps: 1, dissolving ammonium metatungstate, nickel chloride hexahydrate and ferric chloride hexahydrate in water, and stirring to obtain a solution; step 2, atomizing the solution and spraying the atomized solution into liquid nitrogen for pre-freezing to obtain frozen particles; 3, freeze-drying the frozen particles to obtain precursor composite powder; and 4, the precursor composite powder is subjected to roasting and reduction in the hydrogen atmosphere in sequence, and the nano tungsten-nickel-iron composite powder is obtained. According to the preparation method, frozen particles containing tungsten, nickel and iron are obtained through pre-freezing, then solid ice of the frozen particles is directly sublimated into gas to be separated through a freeze-drying process, nanoscale precursor composite powder is obtained, and the nano tungsten-nickel-iron composite powder is prepared through roasting and reduction in the hydrogen atmosphere. The method is suitable for the technical field of powder preparation engineering.

The invention discloses a preparation method of high-purity nano tungsten oxide, which comprises the following steps: S1, dispersing an ammonium metatungstate crude product in ethanol to obtain a mixture, and centrifugally separating the mixture with the ammonium metatungstate crude product to obtain solid ammonium metatungstate and an impurity solution; s2, dissolving the ammonium metatungstate crude product solid ammonium metatungstate in water to obtain an ammonium metatungstate aqueous solution, and then sequentially adding a complexing agent and a chelating agent to obtain a mixed solution; s3, stirring the mixed solution with the ammonium metatungstate crude product, performing evaporative crystallization to obtain crystals, and then calcining the crystals with the ammonium metatungstate crude product to obtain the high-purity nano tungsten oxide with the ammonium metatungstate crude product; according to the method, ammonium metatungstate is primarily purified by utilizing the solubility difference of ethanol on ammonium metatungstate and water-soluble inorganic salt, transition metal impurities and alkaline earth metal ion impurities are sequentially complexed by combining a complexing agent and a chelating agent, step-by-step purification is performed, meanwhile, charge adsorption on the surfaces of particles is reduced, ammonium metatungstate agglomeration is inhibited, and the purity of the ammonium metatungstate is improved. The particle size is uniform and dispersed.

The invention provides a glass substrate through hole machining method, and belongs to the technical field of glass substrates. Comprising the following steps: S1, carrying out ultrasonic cleaning on a glass substrate by using a cleaning solution, and drying; s2, dissolving ammonium tungstate in water, dipping the glass substrate in the solution, dropwise adding concentrated nitric acid for reaction, taking out the glass substrate, calcining, carrying out reverse hydrogen heating reduction, scattering carbon powder on the surface for carbonization, taking out, washing and drying; s3, dissolving an organic zinc salt and an organic aluminum salt in water, adding citric acid and ethylene glycol, adjusting the pH value of the solution, dipping the glass substrate, carrying out a heating reaction, taking out the glass substrate, and calcining the glass substrate; s4, irradiating the target area of the glass substrate with laser to modify the glass in the target area; and S5, carrying out spray etching on the glass substrate to form a through hole, taking out, washing and drying. According to the invention, the problems of easy cracking, crack generation, low adhesion to metal and the like in the traditional glass substrate processing are solved, and the method has industrial application prospects.

The invention relates to the technical field of water electrolysis hydrogen production catalysts, in particular to an integral tungsten-doped ruthenium dioxide catalyst and a preparation method and application thereof.The preparation method comprises the steps that tungstic acid and ruthenium trichloride serve as raw materials and are dissolved in different solvents to prepare precursor solutions, then the precursor solutions are mixed to be uniform, and the integral tungsten-doped ruthenium dioxide catalyst is obtained; and dipping and coating a current collector, and carrying out drying and heating treatment to obtain the integral tungsten-doped ruthenium dioxide catalyst. The tungsten element is uniformly doped on the surface of ruthenium dioxide, so that the catalytic activity and the catalytic stability of the catalyst are greatly improved. And the tungsten-doped ruthenium dioxide catalyst is loaded on the current collector in the form of nano-scale particles, so that more active sites can be exposed, and the catalytic activity and the catalytic stability of the catalyst are further improved. The catalyst can be directly used as a working electrode, the preparation process is simplified, the preparation cost of the anode is saved, and the catalyst has a good application prospect in oxygen evolution reaction in hydrogen production through acidic water decomposition.

The invention discloses a preparation method and application of a catalyst with a high-valence tungsten coordination structure, and the preparation method of the catalyst comprises the following steps: enabling tungstic acid and hydrogen peroxide with specific concentration and proportion to react at a certain temperature to prepare a peroxy tungstic acid solution; dissolving a polydentate organic ligand capable of forming a stable chelation structure with a tungsten center in an organic solvent, mixing the obtained ligand solution with a peroxytungstic acid solution according to a specific ratio, and carrying out a coordination reaction at a certain temperature until the ligand is completely reacted; and finally, carrying out solid-liquid separation, washing and drying to obtain the high-valence tungsten coordination structure catalyst. The catalyst can be used for a reaction for synthesizing glutaraldehyde through cyclopentene oxidation, under the mild condition, hydrogen peroxide serves as a green oxidizing agent, the conversion rate of cyclopentene reaches 90% or above, the selectivity of glutaraldehyde exceeds 60%, the catalyst is stable in structure and can be recycled for 10 times or above, and the problems that in the prior art, a catalyst is difficult to separate, low in activity, poor in stability and the like are solved; the method has a remarkable industrial application value.

The invention belongs to the technical field of chemical mineral detection, and particularly relates to a full-spectrum titration detection method for total iron content in ore. According to the method, after ore sample decomposition is completed, a stannous chloride solution, a sodium tungstate solution, a titanium trichloride solution, a dilute potassium dichromate solution, sulfur-phosphorus mixed acid, a sodium diphenylaminesulfonate solution indicator and a potassium dichromate standard solution are sequentially added into sample liquid, and the whole titration process is measured through a visible light full-spectrum titrator. And presetting a titration condition change point to mark the change of the titration condition, and calculating the total iron content in the ore by taking the volume value corresponding to the full-spectrum titration color change parameter of the titration of the potassium dichromate standard solution as the volume value of the titration end point.