128 results about "Tungstate" patented technology

The invention belongs to the technical field of functional materials, and particularly relates to ultra-thick tabular tungsten oxide and a preparation method thereof.The preparation method of the ultra-thick tabular tungsten oxide comprises the following steps that S1, ammonium tungstate is added into deionized water and stirred to be dissolved at the temperature of 70-90 DEG C, and a clarified ammonium tungstate solution is obtained; s2, cooling the clarified ammonium tungstate solution to normal temperature at a cooling rate of 0.5-2 DEG C / h, and then carrying out suction filtration to obtain plate-shaped ammonium tungstate crystals; s3, calcining the tabular ammonium tungstate crystal to obtain ultra-thick tabular tungsten oxide; ammonium tungstate is adopted as a raw material, controllability is high, tungsten oxide which is uniform in particle size and complete in plate shape is obtained through optimized crystallization and calcination, the purity is larger than or equal to 99%, the problems that traditional tungsten oxide is agglomerated and disordered in shape are solved, functional adaptability is high, the plate-shaped structure can be directionally oriented, the dielectric performance, the breakdown performance and other performance are improved, and the method is suitable for multiple high-end scenes; parameters are easy to control, and operation is simple, green and safe.

The invention belongs to the technical field of electro-catalysis water decomposition, and relates to a self-supporting W-NiCoP / NF composite material and a preparation method and application thereof. Cobalt salt, terephthalic acid, acetic acid and foamed nickel are subjected to a first solvothermal reaction, and defect type Co-MOF / NF is obtained; immersing the defect type Co-MOF / NF into a tungstate solution, and then carrying out a second solvothermal reaction to obtain a defect type W-Co-MOF / NF precursor; and carrying out phosphating heat treatment on the defect type W-Co-MOF / NF precursor and a phosphorus source in an inert atmosphere to obtain the W-Co-MOF / NF composite material. According to the preparation method disclosed by the invention, the tungsten-doped nickel-cobalt bimetallic phosphide with rich defect structures is successfully constructed on the foamed nickel substrate through a step-by-step solvothermal and gas-phase phosphating strategy, so that organic combination of a bimetallic synergistic effect and defect engineering is realized; the prepared self-supporting composite material has more active sites, a better electronic structure regulation effect and better stability.

The invention provides a cobalt tungstate and bismuth vanadate photocatalytic material as well as a preparation method and application thereof, and belongs to the technical field of material synthesis and photocatalytic application. In the presence of monoclinic-phase decahedron BiVO4, CoWO4 nanoparticles grow in situ on an electron-rich (010) crystal face of the CoWO4 nanoparticles through a hydrothermal reaction, and the cobalt tungstate and bismuth vanadate photocatalytic material is obtained. According to the cobalt tungstate and bismuth vanadate photocatalytic material, a simple hydrothermal method is adopted, in the synthesis process, a CoWO4 precursor is guided by electrostatic interaction, preferentially adsorbed and subjected to nucleation growth on the (010) crystal face of BiVO4, a compact chemical bonding interface is constructed through selective growth, the charge migration distance is effectively shortened, and the photocatalytic performance of the material is improved. The interface charge transfer resistance is reduced to the greatest extent, and the formed binary photocatalyst has excellent effects on photocatalytic hydrogen evolution and tetracycline degradation.

The invention discloses a post-treatment liquid and application thereof in an anode foil formation post-treatment process, and the post-treatment liquid comprises the following components in percentage by mass: 0.1-5% of a main film-forming agent, 0.05-3% of a synergistic stabilizer and the balance of a solvent, the main film-forming agent is selected from at least one of a waterborne polyurethane emulsion and a silane coupling agent; the synergistic stabilizer is selected from at least one of organophosphate, molybdate and tungstate. The main film-forming agent and the synergistic stabilizer are compounded to obtain the post-treatment liquid, on one hand, the synergistic stabilizer is firmly combined with an aluminum oxide substrate to carry out deep passivation treatment on an oxidation film on the surface of the anode foil, and on the other hand, the synergistic stabilizer is subjected to network crosslinking with a hydrophobic protection layer formed by the main film-forming agent; the three-dimensional composite protective film can effectively isolate water molecules, repair microdefects on the surface of an oxidation film, prevent the phenomena of specific volume attenuation, leakage current increase and the like of the anode foil, and improve the long-term working reliability of the capacitor.

The invention relates to a rare earth metal tungstate nanosheet material as well as a preparation method and application thereof. The rare earth metal tungstate nanosheet material comprises a PO4 < 3->-LnWO4 nanosheet, and Ln is at least one of lanthanide series rare earth metals. The preparation method comprises the following steps: dissolving phosphotungstic acid and a precursor in a solvent, and stirring to form a solution; adding an organic amine ligand, and stirring to form a transparent solution; performing solvothermal reaction on the solution; and centrifuging, washing with ethanol and drying to obtain the rare earth metal tungstate nanosheet material. A solvothermal reaction method is adopted to successfully construct a two-dimensional sheet structure material formed by interweaving nanowires, the material has high specific surface area, abundant pores and excellent structural stability, and the problems that a traditional photocatalytic material is single in structure and insufficient in active site are effectively solved. The photocatalyst shows excellent degradation capability on various typical antibiotic pollutants, breaks through the limitation that most photocatalytic materials are only effective on single pollutants, and realizes relatively high pollutant degradation universality.

The present application relates to a kind of preparation methods of sulfur vanadium co-doped bismuth tungstate visible light catalyst, the catalyst is assisted by urea hydrothermal method, with sodium tungstate, bismuth nitrate, thiourea, citric acid, ammonium metavanadate, urea as raw material, configuration certain concentration of thiourea and citric acid aqueous solution as sulfur source;Configuration certain concentration of ammonium metavanadate aqueous solution as vanadium source.Sulfur source and vanadium source are mixed after drop by drop to be added to bismuth nitrate solution, after stirring, transfer to hydrothermal kettle, the hydrothermal kettle is placed in blast oven and hydrothermal treatment cooling, centrifugal separation product, washing and drying obtain sulfur vanadium co-doped BWO visible light catalyst.The method is obtained by one-step hydrothermal treatment flower cluster of bismuth tungstate nanosheet composition, simple process, low equipment requirement, the composite photocatalyst prepared has stronger response under visible light condition, has higher application value in pollution control, environmental protection, new energy preparation and other fields.

The invention belongs to the technical field of photothermal conversion materials, and discloses a preparation method and application of an inorganic-organic hybrid polyoxotungstate photothermal material with wide spectrum absorption. The structural formula of the photo-thermal material is Per4W10O32, the crystal structure belongs to a triclinic system, the space group is P-1, and the photo-thermal material has specific unit cell parameters. The preparation method comprises the following steps: oxidizing perylene molecules through constant current electrolysis in a mixed solvent system containing perylene molecules and a decatungstate precursor in an electrochemical oxidation manner, and assembling the oxidized perylene molecules with decatungstate anions to form bulk crystals; the photo-thermal material has continuous strong absorption in a region from ultraviolet light to short wave infrared, the photo-thermal conversion efficiency is as high as 98.24%, when the photo-thermal material is applied to the fields of solar driven interface photo-thermal evaporation and water treatment, the evaporation rate of a two-dimensional system is 1.89 kg.m <-2 >. H <-1 >, the evaporation rate of a three-dimensional hydrogel system is increased to 3.02 kg.m <-2 >. H <-1 >, salt deposition can be inhibited in long-term seawater desalination operation, and the photo-thermal material has a good application prospect. Fresh water quality meets drinking water standards.

The application belongs to the field of antibacterial two-dimensional nanomaterial Mxene catalysts, and particularly relates to a monolayer W@MoS2 nanosheet as well as a preparation method and application thereof. The method comprises the following steps: 1) dissolving water-soluble molybdate and water-soluble tungstate in water to obtain a mixed solution; 2) adding a sulfur source and an organic solvent to the mixed solution, and then performing reaction after mixing, and drying to obtain a powder. The monolayer W@MoS2 nanosheet has a unique two-dimensional planar structure, a large specific surface area, and good optical and electronic properties, and has high light-heat absorption in the near-infrared two region, i.e., the light-heat conversion efficiency is improved. Meanwhile, the peroxidase-like activity of the monolayer W@MoS2 nanosheet material realizes efficient light-heat amplification, can treat methicillin-resistant Staphylococcus aureus infection, and avoids heat therapy damage to normal tissues.

This invention discloses a high-temperature conductive graphene solution and its preparation method, comprising the following components by weight: 1800-2000 parts of a dispersion containing 3-5 nm graphene quantum dots, wherein the quantum dot content is 5-10 wt%; 450-510 parts of tin dioxide with a particle size ≤0.2 μm; 15-20 parts of ammonium tungstate and 15-20 parts of lanthanum oxide; 30-40 parts of manganese chloride tetrahydrate, 20-30 parts of nickel chloride, and 20-30 parts of copper chloride; 8000-10000 parts of a solvent system, wherein deionized water ≤4000 parts, anhydrous ethanol ≤5000 parts, isopropanol ≤100 parts, and n-butanol ≤50 parts; 800-1000 parts of tri-n-butyltin hydride and 100-300 parts of citric acid. Due to the adoption of the above technical solutions, this application has achieved breakthroughs in the stability of conductive networks through quantum dot bridging mechanisms; the standard deviation of electron migration path length has been reduced from 1.2 μm to 0.08 μm; the heterojunction interface has been optimized and a Type-II band structure has been formed, resulting in an 82% reduction in contact resistance.

This invention relates to the field of metal protection and lubrication materials, and discloses a silent, vibration-damping, film-forming, long-lasting rust-preventive oil for bearings and its preparation method. The rust-preventive oil comprises a base oil, a dynamic borate ester-organosilicon-tungsten bridging synergistic modifier, itaconic acid hydrazine, a dimer ester, calcium petroleum sulfonate, polyisobutylene, a phosphate extreme pressure agent, and an antioxidant. The dynamic borate ester-organosilicon-tungsten bridging synergistic modifier forms a reversible dynamic covalent network of borate esters with phenylboronic acid through a diol-based compound, and then undergoes a confined sol-gel polymerization reaction with vinyltriethoxysilane to form silicon-oxygen segments. These segments are then coordinated and bridged by tungstate and diol groups to construct a three-dimensional coupled structure. The rust-preventive oil of this invention has advantages such as high film density, strong adhesion, good vibration damping and noise reduction effect, and strong rust prevention durability, making it suitable for the storage and operational protection of high-end bearings.

The application discloses a method for homogenizing a chemical synthetic multi-component alloy, and the method comprises the following steps: dissolving ammonium molybdate and ammonium tungstate in deionized water to obtain a mixed solution of ammonium molybdate and ammonium tungstate; dissolving polyethyleneimine in deionized water to obtain a polyethyleneimine solution; adding the polyethyleneimine solution into the mixed solution of ammonium molybdate and ammonium tungstate to uniformly disperse the precipitate; completely evaporating the solvent by using a rotary evaporation method to obtain a powder; performing secondary reduction on the powder to obtain a reduced powder; sintering the reduced powder in a graphite mold; heating the sintered product to 1500-1600 DEG C by using a medium-frequency induction furnace, extruding the sintered product on a horizontal extruder, naturally cooling the sintered product, and then annealing the sintered product at 1300-1400 DEG C. Compared with solid-state mixing, the method can save a mechanical alloying process and reduce sintering forming power in solidification forming; compared with liquid-phase mixing, the method can improve the uniformity of element mixing; compared with gas-phase mixing, the method can improve material utilization, reduce preparation cost and homogenization difficulty, and has no environmental pollution.

This invention belongs to the field of metal powder preparation technology, specifically relating to a uniform ultrafine tungsten powder and its preparation method. The preparation method includes the following steps: S1, obtaining an ammonium tungstate solution and a first solvent; the first solvent is obtained by mixing water and ethanol; S2, adding the ammonium tungstate solution and hydrazine hydrate solution dropwise into the first solvent to obtain a first system; the molar ratio of hydrazine hydrate to WO3 in the ammonium tungstate solution is (4-9):1; S3, continuously stirring the first system to allow it to crystallize, then filtering and drying to obtain a precursor powder; S4, heating the precursor powder under a protective gas atmosphere to cause the precursor powder to self-reduction to obtain uniform ultrafine tungsten powder. The prepared uniform ultrafine tungsten powder has a uniform particle size, with an average particle size of 100-400 nm. This invention allows for controllable dosage of the reducing agent, thorough reduction, and uniform tungsten powder particle size; it can obtain high-purity tungsten powder and avoids the introduction of impurities; it has advantages such as simple operation, high reproducibility, short process, simple equipment, easy industrialization, and cost savings.

Provided is a method for preparing a diol. In the method, a saccharide and hydrogen as raw materials are contacted with a catalyst in water to prepare the diol. The employed catalyst is a composite catalyst comprised of a main catalyst and a cocatalyst, wherein the main catalyst is a water-insoluble acid-resistant alloy; and the cocatalyst is a soluble tungstate and / or soluble tungsten compound. The method uses an acid-resistant, inexpensive and stable alloy needless of a support as a main catalyst, and can guarantee a high yield of the diol in the case where the production cost is relatively low.

The invention belongs to the technical field of recycling of rare and noble metal secondary resources, and discloses a method for preparing a tungsten compound and chloroplatinate from a waste catalyst and application of the method. The method comprises the following steps: (1) firing and crushing the waste catalyst, (2) reacting the waste catalyst with acid, (3) filtering and discarding filtrate, (4) reacting the precipitate with ammonia water, filtering to obtain an ammonium tungstate solution, and retaining filter residues; (5) concentrating the ammonium tungstate solution, crystallizing, separating and drying to obtain an ammonium paratungstate finished product; and (6) reacting the filter residues retained in the step (4) with aqua regia to prepare chloroplatinate. And (7) firing the ammonium paratungstate at a high temperature to obtain tungsten trioxide. According to the method, tungsten and platinum can be effectively separated from the carrier, and the recovery rate of rare and precious metals is increased.

The invention discloses a preparation method and application of a zinc negative electrode of a pre-corrosion in-situ modified water-based zinc ion battery, and provides the water-based zinc ion battery at the same time. The zinc negative electrode of the pre-corrosion modified aqueous zinc ion battery is one of a pre-corrosion in-situ zinc tungstate composite zinc electrode (ZnWO), a pre-corrosion in-situ zinc molybdate composite zinc electrode (ZnMoO), a pre-corrosion in-situ zinc vanadate composite zinc electrode (ZnVO) and a pre-corrosion in-situ zinc silicate composite zinc electrode (ZnSiO). The application of the corrosion reaction on the surface of the metal zinc negative electrode is discussed for the first time, the corrosion reaction on the surface of zinc is utilized to form the corresponding compact, multifunctional, stable and insoluble pre-corrosion in-situ zinc salt composite zinc electrode, various side reactions are relieved, uniform zinc deposition is guaranteed, the zinc is not prone to falling off in the repeated zinc deposition stripping process, and the service life of the zinc electrode is prolonged. And finally, stable and long-acting application of the aqueous zinc ion battery is realized.

A method for forming a dehydration catalyst may comprise peptizing a catalyst precursor with an acid, a cellulose ether, or both, thereby forming a catalyst precursor sol, wherein the catalyst precursor comprising a tungstated support of tungsten and at least one of zirconium oxides, zirconium hydroxides, or titanium oxides; subjecting the catalyst precursor sol to kneading and extrusion to form one or more catalyst precursor extrudates; calcining the one or more catalyst precursor extrudates to form a calcined catalyst precursor; and cooling the calcined catalyst precursor to form the dehydration catalyst.

The invention belongs to the technical field of photocatalysis, and provides a preparation method and application of a composite photocatalyst for photodegradation of lignin, the preparation method comprises synthesis of indium zinc sulfide, synthesis of bismuth tungstate and preparation of the composite photocatalyst ZnIn2S4 / Bi2WO6, and the composite photocatalyst is used for photodegradation of lignin in water. According to the present invention, the precursor indium zinc sulfide and the bismuth tungstate are synthesized through the hydrothermal method, and according to the morphology, the different response to light and the inherent characteristics of the indium zinc sulfide and the bismuth tungstate, the ZnIn2S4 / Bi2WO6 Z-type heterojunction is constructed from the indium zinc sulfide and the bismuth tungstate through the physical grinding in-situ method, and the composite photocatalyst has characteristics of more active sites, good light absorption ability, good charge transfer efficiency, and good photocatalytic activity. And the capability of photocatalytic degradation of lignin under visible light is obviously improved.

This invention relates to a method for preparing and applying a ternary heterostructure nanosheet of tungsten diselenide / tin diselenide / tin monoselenide, belonging to the field of gas sensor technology. The invention discloses a ternary heterostructure nanosheet of tungsten diselenide / tin diselenide / tin monoselenide and its application as a sensing material in a highly selective and sensitive flexible NO2 gas sensor. The invention utilizes a liquid-phase growth method, using SnSe2 nanosheets, ammonium tungstate, and diphenyldiselenoether as raw materials, and varying reaction conditions such as temperature, reaction time, and raw material content to prepare the ternary heterostructure nanosheet of tungsten diselenide / tin diselenide / tin monoselenide. Subsequently, these nanosheets are sprayed onto interdigitated electrodes and dried to form a film, thus preparing a chemielectric resistive gas sensor capable of detecting low concentrations of nitrogen dioxide gas at room temperature. It not only possesses high sensitivity and selectivity but can also be applied to flexible NO2 gas sensing.

To provide a new transition metal-doped tungsten molybdic acid doped with one or more transition elements.SOLUTION: In the transition metal-doped tungsten molybdate, a compound represented by MoxW1 - xO3 - nH2O (0 ≤ x ≤ 1, 0 ≤ n) is doped with one or more elements selected from the group consisting of transition elements (excluding Mo and W).SELECTED DRAWING: Figure 1

The invention discloses a cadmium sulfide quantum dot / bismuth tungstate / cadmium tungstate composite photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalytic materials. The cadmium sulfide quantum dot / bismuth tungstate / cadmium tungstate (CdSQDs / Bi2WO6 / CdWO4) composite photocatalyst which has full-spectrum photocatalytic activity and is used for degrading organic pollutants is prepared by adopting a microwave-assisted synthesis technology, and the molar ratio of cadmium sulfide quantum dots to bismuth tungstate to cadmium tungstate is 2: (2-3): (8-12). According to the cadmium sulfide quantum dot / bismuth tungstate / cadmium tungstate composite photocatalyst as well as the preparation method and application thereof, due to the introduction of the cadmium sulfide quantum dots, the light absorption range of bismuth tungstate / cadmium tungstate is widened, and the light utilization rate is increased; the cadmium sulfide quantum dots, the bismuth tungstate and the cadmium tungstate form effective heterojunctions in close contact, so that the separation efficiency of photon-generated carriers is improved, and the photocatalytic performance is effectively improved.

The present disclosure broadly relates to a high temperature chemical process for the synthesis of cesium tungstate in the solid state and the preparation of aqueous solutions or deuterated solutions of cesium tungstate. More specifically, but not exclusively, the present disclosure relates to a high temperature chemical process in which tungsten oxide compounds such as tungsten oxides, or natural or synthetic concentrates such as wolframite or scheelite, tungsten industrial by-products or there mixture thereof, are mixed with cesium compounds such as cesium carbonate, or cesium sulfate, or cesium hydroxide or their mixtures thereof and the mixture is roasted in air or oxygen at high temperature inside a kiln. After cooling, the solid sintered mass containing cesium tungstate is leached or dissolved with water or heavy water for producing dense aqueous solutions or deuterated solutions of cesium tungstate.

The application belongs to the technical field of nanometer material preparation, and particularly relates to a kind of spherical-like nanometer tungsten oxide and a preparation method thereof, wherein the preparation method of the spherical-like nanometer tungsten oxide comprises the following steps: S1, obtaining an ammonium tungstate solution; S2, adding liquid nitrogen dropwise into the ammonium tungstate solution to obtain spherical-like nanometer crystals; and S3, calcining the spherical-like nanometer crystals to obtain spherical-like nanometer tungsten oxide; the application has simple process, strong controllability, easy-to-adjust parameters, simple raw materials, is suitable for large-scale industrial production, introduces liquid nitrogen quenching process, uses ultra-low temperature environment to make solution reach high supersaturation instantaneously and generate a large number of fine crystal nuclei, at the same time, the tiny nitrogen bubbles formed by liquid nitrogen vaporization effectively inhibit the collision and agglomeration between the newly generated crystal nuclei, thereby ensuring good dispersity of the product.

The invention discloses rhenium alloy spherical powder, a preparation method and application, and the preparation method of the rhenium alloy spherical powder comprises the following steps: reacting and drying a metal acid ammonium solution containing ammonium rhenate to obtain precursor powder; the metal acid ammonium solution also comprises at least one of ammonium molybdate and ammonium tungstate; the precursor powder is sequentially subjected to first-stage hydrogen reduction and second-stage hydrogen reduction, and rhenium alloy pre-alloyed powder is obtained; the time of the first-stage hydrogen reduction is 300-450 DEG C, the heat preservation time is 1-2 hours, the time of the second-stage hydrogen reduction is 700-1100 DEG C, and the heat preservation time is 1-3 hours; and radio frequency plasma spheroidizing is conducted on the rhenium alloy pre-alloyed powder, and the rhenium alloy spherical powder is obtained. According to the method, the technical bottlenecks of'uneven components, high oxygen content, poor sphericity and difficulty in SLM forming 'in preparation of the refractory rhenium alloy powder are broken through, and the method has repeatability, parameter controllability and industrialization potential.

The application belongs to the technical field of iodine-containing wastewater treatment, and specifically provides a method for treating iodine-containing wastewater, which comprises the following steps: mixing a metal-doped bismuth tungstate material for treating iodine-containing wastewater with a binder and a conductive agent to prepare a slurry, coating the slurry on a conductive substrate, and drying to obtain a membrane electrode, and using the obtained membrane electrode to treat iodine-containing wastewater; and a preparation method of the metal-doped bismuth tungstate material for treating iodine-containing wastewater, which comprises the following steps: 1) dissolving bismuth salt and iron salt in a solvent to prepare a mixed solution; 2) adding a tungstate solution to the mixed solution to form a suspension, and then performing a hydrothermal reaction, collecting the precipitate after cooling, and washing and drying to obtain the product. The metal-doped bismuth tungstate material prepared by the application has the advantages of high specific surface area and good photo-assisted electric adsorption performance.

The present application relates to metal material anticorrosion technology, and aims to provide a preparation method of bismuth tungstate nanosheet photocatalytic anticorrosion coating. The method comprises the following steps: dispersing bismuth salt precursor and tungstate precursor, and then performing hydrothermal reaction; precipitating, cleaning and drying to obtain Bi2WO6 nanosheet powder; then mixing and uniformly dispersing with anhydrous ethanol, and then uniformly dispersing with a conductive polymer solution; coating the suspension on the surface of a steel sheet, and then drying at room temperature to form a nanosheet coating; uniformly coating a resin coating solution on the nanosheet coating, and then drying to form a Bi2WO6 nanosheet photocatalytic anticorrosion coating. The semiconductor photocatalytic material is directly loaded on the surface of the steel sheet, the conduction of photo-generated electrons is promoted, and the adverse effect of external current required by traditional photoanode anticorrosion is avoided; the transparent resin is uniformly coated on the surface of the nanosheet layer, and the semiconductor photocatalytic anticorrosion coating is constructed, so that the contact of corrosion substances such as water and oxygen with the surface of the steel sheet is effectively avoided, and the compactness and the shielding and anticorrosion capacity of the coating system are improved.

The invention belongs to the technical field of metallurgy, and particularly relates to superfine particle tungsten carbide powder and a preparation method and application thereof.The preparation method comprises the following steps that S1, carbon paste, hydrochloric acid and an ammonium tungstate solution are obtained, the carbon paste and the hydrochloric acid are subjected to first ultrasonic stirring, and a first mixed solution is obtained, performing second ultrasonic stirring on the ammonium tungstate solution and the first mixed solution to obtain a second mixed solution, washing the second mixed solution with pure water, and drying to obtain a tungstic acid and carbon precursor mixture; s2, calcining the tungstic acid and carbon precursor mixture to obtain a tungsten oxide and carbon mixture; s3, the tungsten oxide and carbon mixture is subjected to first carbonization, crushing and sieving, and first tungsten carbide powder is obtained; and S4, the first tungsten carbide powder is subjected to carbon blending to obtain second tungsten carbide powder, and the second tungsten carbide powder is subjected to second carbonization, crushing and sieving to obtain the ultrafine particle tungsten carbide powder. According to the preparation method, the ultrafine particle tungsten carbide powder with the specific surface area of 2.0-3.0 m < 2 > / g, the combined carbon content of 6.10-6.11 wt% and the free carbon content of 0.03-0.04 wt% is prepared by adopting carbon thermal reduction and step-by-step carbonization.

The invention provides a lead-free piezoelectric ceramic material, a preparation method thereof and a piezoelectric device. The lead-free piezoelectric ceramic material is represented by a chemical general formula as follows: (1-x-y) (K1-aNaa) (Nb1-bMb) O < 3-x > AWO < 4-y > BMoO < 4 >, wherein (K1-aNaa) (Nb1-bMb) O3 represents a potassium-sodium niobate-based ceramic material, a is greater than or equal to 0.4 and less than or equal to 0.6, b is greater than or equal to 0 and less than or equal to 0.1, and M is a doped metal element; x and y are mole fractions and satisfy 0 lt; x is less than or equal to 0.05, 0lt; y is less than or equal to 0.05, and 0 lt; x + y < = 0.1; the AWO4 is tungstate, and the BMoO4 is molybdate. Through the synergistic effect of tungstate and molybdate, the sintering temperature of the lead-free piezoelectric ceramic material is reduced, the piezoelectric constant of the lead-free piezoelectric ceramic material is improved, the dielectric loss of the lead-free piezoelectric ceramic material is reduced, the comprehensive performance of the lead-free piezoelectric ceramic material is greatly improved, and the lead-free piezoelectric ceramic material can be applied to piezoelectric devices such as piezoelectric motors with high requirements for piezoelectric performance.

The invention discloses a crevice corrosion and flash corrosion resisting liquid medicine for an MSAP process and a using method of the crevice corrosion and flash corrosion resisting liquid medicine. The flash etching liquid medicine comprises 40-60 g / l of sulfuric acid, 20-30 g / l of hydrogen peroxide, 0.5-2.0 g / l of a stabilizer, 2.0-5.0 g / l of hyperbranched polyol, 0.1-0.5 g / l of tungstate, 0.02-0.04 g / l of a wetting agent and the balance of water. The number-average molecular weight of the hyperbranched polyol is 500 to 1200, and the hydroxyl value of the hyperbranched polyol is 500 to 700 mKOH / g. Through the synergistic effect of the hyperbranched polyol and the tungstate, the corrosion reaction in the included angle gap is effectively inhibited, the bottom lateral erosion amount can be controlled within 0.5 [mu] m, the problem of accelerated lateral erosion caused by the included angle gap in the IC carrier plate MSAP process is solved, and the processing requirement of a high-end IC carrier plate for a fine circuit is met.

The invention belongs to the technical field of impurity removal in tungsten smelting, and particularly relates to a method for removing magnesium from an ammonium tungstate solution, which comprises the following steps: obtaining silicic acid and the ammonium tungstate solution, adding the silicic acid into ammonia water, and stirring to obtain a silicic acid solution, the ammonium tungstate solution contains magnesium element, and the concentration of the ammonia water is greater than or equal to 2mol / L; removing molybdenum from the ammonium tungstate solution; a silicic acid solution is added into the ammonium tungstate solution with molybdenum removed, stirring is conducted, and the molar ratio of silicic acid to magnesium in the ammonium tungstate solution is 0.8-3.0; according to the method, a solid-liquid form is replaced by a liquid-liquid form to remove magnesium, so that the reaction is more sufficient, and the reaction efficiency is improved; by controlling the concentration of ammonia water, the tungsten loss in the magnesium removal process is reduced; by controlling the addition amount of silicic acid, excessive introduction of silicon is avoided while deep magnesium removal is performed, so that ammonium paratungstate meeting national standard zero-level requirements is prepared.

The invention discloses an immunosensor for detecting porcine epidemic diarrhea virus as well as a preparation method and a detection method of the immunosensor. The preparation method of the immunosensor for detecting the porcine epidemic diarrhea virus comprises the following steps: S1, sequentially adding H2O2 and concentrated nitric acid into an aqueous solution of tungstate for reaction to obtain a modification solution; s2, performing electrochemical deposition on the glassy carbon electrode by taking the modification liquid as electrolyte; s3, taking an aniline solution composed of concentrated sulfuric acid, aniline and water as an electrolyte, and performing electrochemical polymerization on the glassy carbon / tungsten oxide electrode; s4, placing the glassy carbon / tungsten oxide / polyaniline electrode in a chloroauric acid solution for electro-deposition; s5, dispensing a porcine epidemic diarrhea virus antibody on the surface of the glassy carbon / tungsten oxide / polyaniline / gold electrode, and incubating; and S6, dropwise adding bovine serum albumin on the surface of the glassy carbon / tungsten oxide / polyaniline / gold-antibody electrode, and sealing. The sensor has the advantages of high detection speed, high stability, strong anti-interference performance and the like.