32results about How to "Non-toxic method" patented technology

The invention belongs to the field of electrochemistry battery, and more specifically relates to a black phosphorus nanosheet-graphene composite film anode used for flexible lithium ion batteries, and a preparation method thereof. According to the preparation method, high purity and large scale black phosphorus blocks are synthesized via mineral substance assistant vapor transporting method with high efficiency; a large amount of clean and high quality black phosphorus sheets are prepared in water via ultrasound treatment; the clean and high quality black phosphorus sheets and high conductive graphene nanosheets prepared via intercalation stripping method are subjected to mixing ultrasonic dispersion; and flexible high-strength laminated composite film is prepared via vacuum filtration. The preparation process of the flexible high-strength laminated composite film is simple and controllable; large scale low cost preparation can be realized; black phosphorus nanosheets are high in capacity, graphene is high in electrical conductivity, and the black phosphorus nanosheets and graphene both possess two-dimensional structures high in flexibility and strength, so that problems the black phosphorus is poor in electrical conductivity and stability are solved, lithium ion battery capacity, cycling stability, and entire energy density are increased, and lithium ion battery electrode integrated flexible design is realized.

The invention relates to a preparation method of porous boron nitride nanofibers. The preparation method mainly utilizes a three-step synthesis method, namely (1) synthesizing melamine diboronic acid precursor powder from boric acid and melamine in a hydrothermal manner; (2) rapidly freezing and cooling a hot water solution of a melamine diboronic acid precursor with liquid nitrogen by virtue of a freeze-drying method, then drying, and synthesizing melamine diboronic acid nanofibers; and (3) carrying out high-temperature thermal cracking on the melamine diboronic acid nanofibers in protective atmosphere, so as to obtain the porous boron nitride nanofibers. According to the preparation method, molecular crystals of melamine diboronic acid are rapidly separated and nucleated by virtue of a freeze drying technique, so that the growth of the crystals is avoided; the diameters of the prepared porous boron nitride nanofibers reach a nanometer scale, and the porous boron nitride nanofibers are high in purity, uniform in shape, high in slenderness ratio and large in specific surface area.

The invention belongs to the field of food and medicine and relates to a method for improving the viscosity of gelatin by using a glutamine transaminase for catalyzing gelatin crosslinking. According to the method, gelatin molecules are catalyzed to crosslink by using the glutamine transaminase at a certain pH value and temperature, the adjustment on the viscosity of the gelatin can be realized through controlling the reaction time and the addition of the glutamine transaminase. The method can be widely applied to bone gelatin and skin gelatin which are prepared by acid, alkali and enzyme methods. The method disclosed by the invention is safe and non-toxic, is simple in process and is applicable to gelatin production plants or application units; and the viscosity of the gelatin is improved through the method disclosed by the invention, so that the quality and application value of the gelatin are improved.

The invention relates to a preparation method of a boron nitride nano tube. The method comprises the steps of carrying out ball milling on metal magnesium powder and low-cost boron oxide as a boron source instead of B to prepare a precursor; preparing the pure-phase boron nitride nano tube with a high length-diameter ratio in high-temperature ammonia gas atmosphere in a vertical induction heating furnace. According to the invention, used raw materials are boron oxide powder and metal magnesium powder which both belong to ordinary chemical raw materials which are industrially produced, are low and easily available and non-toxic; the synthesized boron nitride nano tube is high in purity, large in length-diameter ratio, little in defect and uniform in morphology; the method is non-toxic, reliable and suitable for synthesis on large scale; the prepared boron nitride nano tube can be applied to the fields of nanoelectronics, electronic heat dissipation elements, solid / liquid lubricants, nano composite materials, high-temperature structure members and the like.

The invention relates to a preparation method of biobased water-borne UV (ultraviolet) curing environment-friendly nail polish. The preparation method is characterized by comprising the following steps of weighing 30 to 50% of biobased water-borne UV curing environment-friendly nail polish resin, 5 to 10% of deionized water, 40 to 60% of pigment, 0.1 to 0.5% of wetting dispersant, 0.1 to 0.5% of flatting agent, 0.2 to 0.5% of defoaming agent, and 1.0 to 2.0% of thickener; adding the pigment, the wetting dispersant, the flatting agent, the defoaming agent and the deionized water into a ball mill to mill, so as to obtain a color paste a; adding the biobased water-borne UV curing environment-friendly nail polish resin into the color paste a, stirring at high speed, adding the thickener, and filtering by a 200-mesh filter net, so as to obtain the biobased water-borne UV curing environment-friendly nail polish. The prepared biobased water-borne UV curing environment-friendly nail polish has the characteristics that the curing speed is quick, the transparency is good, the storage stability and luster are high, the adhesion force is good, and the like. The preparation method has the advantages that the green, environment-friendly, non-toxic and non-odor effects are realized, and the product cost is reduced.

The invention provides a method for preparing an oil body. The method comprises the following steps: (i) providing an oil material; (ii) damaging cell walls and / or damaging cellulose, pectin, hemicellulose or glucan in the cell walls of the oil material in the presence of water and an enzyme; (iii) separating to obtain the oil body.

The invention provides a method for simultaneously preparing an oil body and non-hydrolyzed protein, comprising the following steps: (i) providing an oil material; (ii) in existence of water and enzyme, destroying the cell walls of the oil material and / or destroying cellulose, pectin, hemicellulose or glucan in the cell walls of the oil material; and (iii) separating the oil body and protein obtained by reaction.

The invention discloses a preparation method of a silver phosphate film, belonging to a preparation method of a photo-catalytic and photo-electrochemical material of a semiconductor. The preparation method of the silver phosphate film comprises the following steps: (1) ultrasonically washing a glass or silicon wafer substrate by using ethyl alcohol and an acetone reagent sequentially; (2) depositing an Ag film on the substrate by using sputtering and thermal evaporation methods; (3) dropwise adding silver nitrate AgNO3 to the Ag film until the Ag film is fully filled with silver nitrate AgNO3, carrying out spin-coating and drying; and then dropwise adding a disodium hydrogen dodecahydrate Na2HPO4 aqueous solution, carrying out spin-coating and drying; and (4) putting the Ag film in a muffle furnace, heating to 300-550 DEG C, and sintering for 0.5-3h under the condition of preserved temperature to obtain the silver phosphate Ag3PO4 film, wherein the mass percent concentration of a silver nitrate AgNO3 aqueous solution is 0.017%-0.34%; the mass percent concentration of the disodium hydrogen dodecahydrate Na2HPO4 aqueous solution is 0.014%-0.28%; the silver phosphate Ag3PO4 film with the structure has a thickness of 0.3-10 microns. The preparation method of the silver phosphate film has the advantages that the method is simple, non-toxic and easy to operate; the inert atmosphere protection is not needed in the method, so that the method is low in cost and suitable for industrial production; the film prepared by the method is relatively good in adhesive force; and the thickness of the film is easy to control.

The invention relates to a novel method for preparing a chiral dicarbonyl derivative by catalysis, needs to overcome various defects in the conventional method for preparing the chiral dicarbonyl derivative and provides an environment-friendly, economic, efficient and nontoxic method for preparing the chiral dicarbonyl derivative. The method of the invention is characterized in that a chiral diamine derivative is used as a catalyst, the molar ratio of the catalyst to raw materials is 1:10-20 and the target product, namely the chiral dicarbonyl derivative is obtained by performing reaction at the normal pressure and the room temperature in a non-polar solvent; the raw materials are an achiral dicarbonyl derivative and a nitroolefin derivative and the molar ratio of the using amount of the achiral dicarbonyl derivative to the using amount of the nitroolefin derivative is 1:1; the non-polar solvent is toluene; and the catalyst is one of the following catalysts from a to i.

The invention discloses a heterostructure catalyst for decomposing water into hydrogen by utilizing solar energy and a preparation method of the catalyst, and belongs to a preparation method of a semiconductor photocatalytic material. The preparation method comprises the following steps: 1) dispersing SiO2 nanospheres into deionized water, adding urea and nickel nitrate, and uniformly conducting mixing; 2) transferring the mixed solution into a hydrothermal reaction kettle, and conducting reacting at 105 DEG C for 12 hours; (3) after natural cooling, centrifuging a product, and drying the product to obtain SiO2-coated nickel silicate powder; (4) dispersing the SiO2-coated nickel silicate into deionized water, adding sodium sulfide, and adjusting the pH of a mixed solution by using NaOH; 5) transferring the mixed solution into a hydrothermal reaction kettle, and conducting reacting at 160 DEG C for 12-20 hours; 6) after natural cooling, centrifugally collecting black precipitates, and performing vacuum drying to obtain NiS hollow nanosphere powder; 7) dissolving NiS and glycerin in water, and adding zinc chloride, indium chloride and thioacetamide; 8) reacting the solution for 2 hours at 80 DEG C in a stirring state; and 9) carrying out centrifugation, washing and drying to obtain NiS-coated ZnIn2S4. The NiS-coated ZnIn2S4 spherical heterostructure has the advantages of large specific surface area, low density, good surface permeability and visible light response.

The invention discloses a preparation method of a visible light absorption layer based on an Ag3PO4 film, and belongs to a preparation method of photocatalysis and photoelectric materials. The visible light absorption layer is prepared by using a four-step process including coprecipitation, spin coating, drying and sintering, and the method comprises the steps of 1) preparing Ag3PO4 nano-scale ultrafine powder of which the size scale is between 20 and 500 nm by using a coprecipitation method; 2) ultrasonically dispersing the Ag3PO4 powder into transparent organic solvents, and performing spin coating on the obtained sol shaped dispersion liquid on a substrate to obtain a prefabricated Ag3PO4 film layer; and 3) putting the prefabricated Ag3PO4 film layer into an oven at the temperature of 20-80 DEG C for drying, and putting into a muffle furnace for sintering and removing organic residues. The Ag3PO4 visible light absorption layer has a thickness of 0.2-10 microns, and is high in response characteristics and adhesive force of visible light; because the visible light absorption layer is used as a photocatalyst, the visible light absorption layer is easy to recover, can be used for a photo-anode of a photoelectrochemical cell, and has a large application potential on the fields of light degradation pollutants, photolysis of water, photovoltaic conversion and the like. The method is simple, free of toxicity, easy to operate and low in cost.

The invention relates to a method for detecting lithium ion content of an anodization tank liquid. The method comprises the steps of apparatus analysis condition selection, reagent preparation, standard solution preparation, spectrum measurement, theoretical tank liquid preparation and spectral measurement. The invention provides the method for detecting lithium ion content of an anodization tank liquid by an inductively coupled plasma emission spectrometer (ICP-OES). The method can effectively shorten analysis detection time by 50% and fills in the blank of detection of the metal ion content of the anodization tank liquid by the inductively coupled plasma emission spectrometer. The method is accurate, simple and fast. The method widens application of the inductively coupled plasma emission spectrometer in the tank liquid analysis field, is nontoxic and environmentally friendly and effectively solves the problem of environmental pollution in tank liquid analysis.

The invention relates to a preparation method of a TiO2 grading structure with visible light response, and belongs to a preparation method of a semiconductor photocatalysis and photoelectric chemical material. According to the method, firstly, villiaumite is dissolved in water; acetic acid is dropwise added into the villiaumite water solution; continuous stirring is performed; then, tetra-n-butyl titanate is dropwise added into an obtained mixed solution, and continuous stirring is performed; the mixed solution is put into a hydrothermal reaction kettle; the temperature is raised to 140 to 180 DEG C, enabling the reaction to be performed for 8 to 16h; after the reaction kettle is naturally cooled, precipitates are taken out; centrifugation or filtering, washing and drying are performed; the temperature is raised to 300 to 550 DEG C in air atmosphere; heat insulation sintering is performed for 0.5 to 3h. The prepared TiO2 grading nanometer structure has the advantages of large specific surface area, visible light response, single-crystal structure and the like, and is suitable for being applied to the fields of photocatalytic degradation of pollutant, photoelectrocatalysis water decomposition hydrogen production and the like. The preparation method has the advantages that the method is simple and nontoxic; the operation is easy; the cost is low; the preparation method is suitable for industrial production.

The invention provides a cleaning method of polyacrylonitrile carbon fiber precursor drying and densifying equipment. The cleaning method comprises the following steps: 1, smearing soil on the drying and densifying equipment; and 2, coating the soil with cloth and wiping the drying and densifying equipment to remove attachments on the surface of the drying and densifying equipment. According to the cleaning method of the polyacrylonitrile carbon fiber precursor drying and densifying equipment, the cleaning effect is good, the surface of the densifying equipment equipment is not damaged, and the performance of a precursor and a carbon fiber is not affected.

The invention relates to a deoxidized fresh-keeping method for pleurotus eryngii, and belongs to the technical field of fresh keeping of edible fungi. The deoxidized fresh-keeping method comprises thefollowing steps of 1, iron powder activation; 2, slow release of activated iron powder, wherein the activated iron powder is coated with hydrophobically modified sodium alginate; 3, preparation of adeoxidizing agent, wherein the deoxidizing agent is an iron-based deoxidizing agent; 4, packaging of the deoxidizing agent, wherein the prepared deoxidizing agent is put into 4-centimeter-long and 3-centimeter-wide breathable small packaging bags with holes; 5, pre-cooling of the raw material, wherein the pleurotus eryngii is pre-cooled for 24 hours at the temperature of 8 DEG C; 6, subpackaging of the raw material, wherein the pre-cooled pleurotus eryngii is subpackaged into polyethylene packaging bags; 7, deoxidized packaging; 8, low-temperature storage. By means of the fresh-keeping method,the cold storage life of the pleurotus eryngii can be obviously prolonged, and the original flavor and taste of the pleurotus eryngii can be well maintained. The method is simple in operation, safe,free of toxicity, low in cost and wide in market application prospect.

The invention discloses a method for reducing microbiological indicators of corn starch, and belongs to the technical field of corn starch. The invention discloses a method for reducing microbial indicators of corn starch, and the method comprises ozone treatment, ultraviolet treatment, filtration and temperature control for reducing the microbial indicators of washing water. Reverse osmosis water is added into washing water, so that the buffering capacity of the water is reduced, and pH regulation and control are facilitated; ozone is introduced into a pipeline for conveying starch milk, so that the microbiological indicators of the material is reduced. According to the method disclosed by the invention, no pollution is caused in the production process, the use is convenient, the effect is obvious, and the microbiological indicators in the obtained corn starch can be effectively controlled below the national hygienic standard requirement of edible corn starch.

The invention discloses a polysubstituted oxazoline compound and a preparation method thereof. In the present invention, 0.15-0.45 mmol N-(1-substituted vinyl) substituted amide, 0.15 mmol α-carbonylthio ylide, 10 mol% silver salt catalyst and 0.15 mmol additive are sequentially added into Schlenk sealed tube under nitrogen atmosphere to mix, The mixture was heated to 60-120° C. and stirred for 12-24 h, then the reaction solution was cooled to room temperature, and the polysubstituted oxazoline compound was obtained by separation by silica gel column chromatography. The reaction conditions required by the preparation method of the invention are mild, the raw materials used include enamide and sulfur ylide are cheap and easy to obtain, and the substrate is suitable for a wide range. Compared with the traditional oxazoline synthesis route, the method is greener, non-toxic, and has more synthetic steps. The target product can be obtained simply and in high yield, and the obtained oxazoline compound has potential application prospects in the field of pharmaceutical synthesis.

The invention discloses a cobalt-lanthanum co-doped visible-light response BiVO4 photoelectrode and a preparation method thereof, and belongs to the field of nano functional materials. The method comprises the following steps: 1) adding p-benzoquinone and ethanol into an aqueous solution dissolved with potassium iodide and bismuth nitrate, and fully stirring; 2) taking the solution as an electrolyte, carrying out electro-deposition for 5-15 minutes, and depositing on a conductive substrate to obtain a bismuth oxyiodide (BiOI) film; 3) dissolving vanadyl acetylacetonate in dimethyl sulfoxide, adding a proper amount of cobalt source and lanthanum source, and uniformly stirring and mixing; (4) transferring the dimethyl sulfoxide solution mixed with the vanadium source, the cobalt source and the lanthanum source, and uniformly coating a bismuth oxyiodide (BiOI) film with the dimethyl sulfoxide solution; 5) transferring into a muffle furnace, and calcining for 1-2 hours at the temperature of 400-550 DEG C; and (6) taking out a sample, soaking the sample in a sodium hydroxide solution for 30-60 minutes, cleaning and drying to obtain the cobalt-lanthanum co-doped bismuth vanadate (Co / La-BiVO4) nano-porous electrode. The preparation method has the advantages that the visible light response of the BiVO4 film can be effectively enhanced through co-doping of cobalt and lanthanum elements, and better photoelectrochemical hydrogen production performance is obtained.

The invention discloses a preparation method of a visible light absorption layer based on an Ag3PO4 film, and belongs to a preparation method of photocatalysis and photoelectric materials. The visible light absorption layer is prepared by using a four-step process including coprecipitation, spin coating, drying and sintering, and the method comprises the steps of 1) preparing Ag3PO4 nano-scale ultrafine powder of which the size scale is between 20 and 500 nm by using a coprecipitation method; 2) ultrasonically dispersing the Ag3PO4 powder into transparent organic solvents, and performing spin coating on the obtained sol shaped dispersion liquid on a substrate to obtain a prefabricated Ag3PO4 film layer; and 3) putting the prefabricated Ag3PO4 film layer into an oven at the temperature of 20-80 DEG C for drying, and putting into a muffle furnace for sintering and removing organic residues. The Ag3PO4 visible light absorption layer has a thickness of 0.2-10 microns, and is high in response characteristics and adhesive force of visible light; because the visible light absorption layer is used as a photocatalyst, the visible light absorption layer is easy to recover, can be used for a photo-anode of a photoelectrochemical cell, and has a large application potential on the fields of light degradation pollutants, photolysis of water, photovoltaic conversion and the like. The method is simple, free of toxicity, easy to operate and low in cost.

The invention relates to a preparation method of a foamed boron nitride block material. The preparation method comprises the following steps: (1) preparing a melamine-boric acid-water mixed solution; (2) carrying out ultrasonic treatment for 1h to 24h by an ultrasonic apparatus; separating out a white block body; (3) putting the white block body and a residual solution into a freezing dryer; freezing and pumping in vacuum to obtain a dried white solid precursor; (4) keeping the heat of the white solid precursor at 900 DEG C to 1500 DEG C for 2h to 6h under a protective atmosphere; cooling under the protective atmosphere to room temperature, so as to obtain a white block-shaped solid substance, namely a block-shaped boron nitride foam material. According to the preparation method of the foamed boron nitride block material, the energy consumption and cost of production are reduced; the method has no toxin and has high efficiency, and is applicable to large-scale and industrial synthesis of the foamed boron nitride block material; the prepared foamed boron nitride block material is composed of boron nitride micro-nano fibers with a high length-diameter ratio, and has the characteristics of good connectivity, large specific surface area, super hydrophobicity and the like.

The invention discloses a heterogeneous structure catalyst and a preparation method for decomposing water to produce hydrogen by using solar energy, and belongs to the preparation method of semiconductor photocatalytic materials. Steps: 1) SiO 2 Disperse the nanospheres in deionized water, add urea and nickel nitrate and mix evenly; 2) transfer the mixed solution to a hydrothermal reaction kettle, and react at 105°C for 12h; 3) after natural cooling, centrifuge and dry the product to obtain SiO 2 @nickel silicate powder; 4) SiO 2 Disperse @nickel silicate into deionized water, add sodium sulfide, and adjust the pH of the mixed solution with NaOH; 5) Transfer the mixed solution to a hydrothermal reaction kettle and react at 160°C for 12‑20h; 6) After natural cooling, centrifuge to collect the black Precipitation and vacuum drying to obtain NiS hollow nanosphere powder; 7) Dissolve NiS and glycerin in water, add zinc chloride, indium chloride and thioacetamide; 8) react the solution at 80°C for 2h under stirring; 9) After centrifugation, washing and drying, NiS@ZnIn was obtained 2 S 4 . Pros: NiS@ZnIn 2 S 4 Spherical heterostructures have large specific surface area, low density, good surface permeability and visible light response.

A TiO with visible light response 2 The preparation method of the hierarchical structure belongs to the preparation method of semiconductor photocatalysis and photoelectrochemical materials. First, dissolve the fluoride salt in water, add acetic acid dropwise into the fluoride salt solution, and continue stirring; then add tetra-n-butyl titanate dropwise into the mixed solution, and continue stirring; place the mixed solution in a hydrothermal reaction kettle , raise the temperature to 140~180℃ and allow it to react for 8~16h; after cooling the reactor naturally, take out the precipitate, centrifuge or filter, wash and dry; raise the temperature to 300~550℃ in an air atmosphere, and keep sintering for 0.5~3h . The prepared TiO 2 Hierarchical nanostructures have the advantages of large specific surface area, visible light response, and single-crystal structure, and are suitable for applications in photocatalytic degradation of pollutants, photoelectrocatalytic water splitting, and hydrogen production. It has the advantages of simple method, non-toxicity and easy operation. It has low cost and is suitable for industrial production.

The invention discloses a method for preparing a silver phosphate thin film, which belongs to the method for preparing semiconductor photocatalysis and photoelectrochemical materials. Steps: 1) Use alcohol and acetone reagents to ultrasonically clean the glass or silicon wafer substrate in sequence; 2) Deposit a layer of Ag film on the substrate by sputtering and thermal evaporation; 3) Drop silver nitrate AgNO on the Ag film layer. 3 , spin coating, drying; then drop disodium hydrogen phosphate Na 2 HPO 4 Aqueous solution, spin coating and drying; 4) Place it in a muffle furnace, raise the temperature to 300-550°C, heat-preserve and sinter for 0.5-3 hours to obtain silver phosphate Ag 3 PO 4 film. The silver nitrate AgNO 3 The mass percentage concentration of aqueous solution is 0.017%-0.34%; Described disodium hydrogen phosphate Na 2 HPO 4 The mass percent concentration of the aqueous solution is 0.014%-0.28%; the silver phosphate Ag 3 PO 4 The film is a structure with a thickness of 0.3-10 μm. Advantages: 1. The method of the present invention is simple, non-toxic and easy to operate. 2. The method of the present invention does not need to be protected by an inert atmosphere, has low cost, and is suitable for industrial production. 3. The adhesion of the obtained film layer is good, and the thickness of the film layer is easy to control.

The invention belongs to the field of electrochemistry battery, and more specifically relates to a black phosphorus nanosheet-graphene composite film anode used for flexible lithium ion batteries, and a preparation method thereof. According to the preparation method, high purity and large scale black phosphorus blocks are synthesized via mineral substance assistant vapor transporting method with high efficiency; a large amount of clean and high quality black phosphorus sheets are prepared in water via ultrasound treatment; the clean and high quality black phosphorus sheets and high conductive graphene nanosheets prepared via intercalation stripping method are subjected to mixing ultrasonic dispersion; and flexible high-strength laminated composite film is prepared via vacuum filtration. The preparation process of the flexible high-strength laminated composite film is simple and controllable; large scale low cost preparation can be realized; black phosphorus nanosheets are high in capacity, graphene is high in electrical conductivity, and the black phosphorus nanosheets and graphene both possess two-dimensional structures high in flexibility and strength, so that problems the black phosphorus is poor in electrical conductivity and stability are solved, lithium ion battery capacity, cycling stability, and entire energy density are increased, and lithium ion battery electrode integrated flexible design is realized.

The invention relates to a preparation method of a boron nitride nano tube. The method comprises the steps of carrying out ball milling on metal magnesium powder and low-cost boron oxide as a boron source instead of B to prepare a precursor; preparing the pure-phase boron nitride nano tube with a high length-diameter ratio in high-temperature ammonia gas atmosphere in a vertical induction heating furnace. According to the invention, used raw materials are boron oxide powder and metal magnesium powder which both belong to ordinary chemical raw materials which are industrially produced, are low and easily available and non-toxic; the synthesized boron nitride nano tube is high in purity, large in length-diameter ratio, little in defect and uniform in morphology; the method is non-toxic, reliable and suitable for synthesis on large scale; the prepared boron nitride nano tube can be applied to the fields of nanoelectronics, electronic heat dissipation elements, solid / liquid lubricants, nano composite materials, high-temperature structure members and the like.

The invention relates to a method for deoxidizing fresh-keeping of Pleurotus eryngii, and belongs to the technical field of fresh-keeping of edible fungi. It includes the following steps (1) activation of iron powder; (2) sustained release of activated iron powder: the activated iron powder is wrapped with hydrophobically modified sodium alginate; (3) configuration of deoxidizer: the deoxidizer is an iron-based deoxidizer; ( 4) Packaging of deoxidizer: put the prepared deoxidizer into a small air-permeable and perforated packaging bag with a length of 4cm and a width of 3cm; (5) Pre-cooling of raw materials: place the king oyster mushroom in an environment of 8 ℃ for pre-cooling for 24 hours ; (6) Packing of raw materials: Pack the pre-cooled loquats into transparent polyethylene packaging bags; (7) Deoxygenation packaging; (8) Low temperature storage. The fresh-keeping method of the invention can significantly prolong the refrigerating period of the king oyster mushroom, and better maintain the original flavor and taste of the king oyster mushroom. The method is easy to operate, safe, non-toxic and low in cost, and has broad market application prospects.

A preparation method of bio-based water-based UV curing environment-friendly nail polish, by weighing 30-50% of bio-based water-based UV curing environment-friendly nail polish resin, 5-10% of deionized water, 40-60% of pigment, moistening Wet dispersant 0.1-0.5%, leveling agent 0.1-0.5%, defoamer 0.2-0.5% and thickener 1.0-2.0%; add pigment, wetting and dispersing agent, leveling agent, defoamer to the ball mill Grind with deionized water to obtain color paste a; add bio-based water-based UV curing environmentally friendly nail polish resin to color paste a, add thickener after high-speed stirring, and filter through a 200-mesh filter to obtain bio-based water-based UV curing environmental protection nail polish. The nail polish prepared by the invention has the characteristics of fast curing speed, good transparency, storage stability, high gloss, good adhesion, etc. The method of the invention is green, environmentally friendly, non-toxic and tasteless, and reduces product cost.

The invention discloses the preparation of an ultra-thin porous nano-carbon nitride photocatalyst and its application in photocatalytic oxidation of fructose to synthesize lactic acid, which belongs to the technical field of catalysis. The preparation method of the catalyst is as follows: dispersing the nitrogen-containing compound precursor and manganese acetate hydrate in deionized water, and then calcining to obtain the Ut-OCN material with oxygen heteroatoms introduced into the structure. The application process of the catalyst in the photocatalytic oxidation of fructose to synthesize lactic acid is as follows: mix the Ut-OCN photocatalyst, fructose and alkaline solution, and react with visible light at 20-80°C for 45-180min; Determination of lactic acid content by liquid chromatography. The method for preparing the catalyst of the present invention has better universality, and the catalyst used has the advantages of high catalytic activity, good thermal stability, recyclability, etc., lactic acid is synthesized by simple and efficient catalysis, and has good application prospect.