99results about How to "Many cycles" patented technology

The invention relates to an additive which can be added to buffers used in nucleotide detection processes and improved methods of nucleic acid sequencing using this additive. In particular the invention relates to use of the additive to improve the efficiency of fluorescence-based multiple cycle nucleic acid sequencing reactions.

The invention discloses a preparation method of a noble metal-loaded activated carbon fiber monoatomic catalyst for catalytic degradation of VOCs at room temperature. The method includes the steps of:(a) pretreatment of a carrier: immersing activated carbon fiber in a sulfuric acid solution, performing ultrasonic treatment, then subjecting the ultrasound treated solution to heating reaction in awater bath pot, then performing cleaning with distilled water to neutral, and conducting natural airing to obtain modified activated carbon fiber; (b) noble metal loading: impregnating the modified activated carbon fiber in a noble metal solution, and performing ultrasonic treatment and standing, then adding a sodium hydride solution to reduce noble metal, finally taking out the activated carbon fiber, and conducting washing and drying to obtain a noble metal-loaded activated carbon fiber semi-finished product; and (c) calcination: putting the noble metal-loaded activated carbon fiber semi-finished product in a muffle furnace for calcination, thus obtaining the noble metal-loaded activated carbon fiber monoatomic catalyst finally. The method provided by the invention greatly improves the catalytic degradation efficiency of the monoatomic catalyst.

The invention discloses a method for quickly acclimatizing active sludge mixed flora to prepare polyhydroxyalkanoate (PHA) by using an aerobic dynamic drainage method and relates to a method for preparing the PHA. The invention solves the problems that the acclimatization time for synthesizing PHA through active sludge mixed flora is long, a reactor works unstably and the synthesized PHA is low in content in the prior art. The method comprises the following steps: 1, active sludge is put into a sequencing batch reactor (SBR); 2, 6-12 hours are taken as a cycle of operation, in the cycle of operation, two-time water introduction, precipitation and drainage are carried out, the drainage rate is 1:1, during the first water introduction, a carbon source and various nutrients are introduced, and during the second water introduction, only the supplement of nitrogen nutrient is carried out; 3, 2-4 cycles are operated every day, the sludge detention time is 1-10 days and sludge-water mixed liquid is collected; 4, batch experiments are carried out, half supernatant is discharged, equivalent carbon source is supplemented, aeration, precipitation and drainage are carried out, and the process is repeated for 6 to 8 times. The invention belongs to the field of biodegradable plastic synthesis.

The invention relates to a preparation method of a supported catalyst for synthesizing chloroaniline through catalytic hydrogenation of chloronitrobenzene and particularly relates to a preparation method of a nitrogen-doped carbon material supported noble metal catalyst applied to the synthesis of chloroaniline through catalytic hydrogenation. The catalyst has the advantages of high catalytic activity, dechloridation inhibition capacity, long service life and the like, and the prepared chloroaniline product is high in purity.

The invention discloses a cobalt-free lithium-rich manganese-based cathode material as well as a preparation method and application thereof. The cathode material has a chemical formula Li[1+x]Ni[y]Mn[0.8-y]O2 (x is more than 0 and less than 1 / 3 and y is more than 0 and less than 0.8). The preparation method comprises the following steps: preparing a precursor in an ethanol or de-ionized water solvent by adopting a sol-gel method, pre-sintering at the low temperature, performing ball-milling, and performing high-temperature solid-phase sintering to obtain the cathode material. The cathode material prepared by adopting the method is applied to lithium ion batteries, is high in specific discharge capacity (278mAh / g) and energy density, is expected to replace commercialized mainstream products-LiCoO2 cathode materials and lithium iron phosphate power batteries, and becomes a novel material of high-specific-capacity cathode materials for electric vehicles at present.

The invention relates to a method for preparing phase change energy storage material in the MgCl2*6H2O-CaCl2*6H2O system. The method includes: firstly, mixing MgCl2*6H2O and CaCl2*6H2O to obtain mixture; and secondly, sequentially adding nucleating agent and thickening agent into the mixture, mixing well, and packing to obtain the phase change energy storage material with phase change temperature of 20 DEG C to 25 DEG C, wherein the MgCl2*6H2O in the mixture is 5%-30% in mass fraction, and each of the nucleating agent and the thickening agent accounts for 1%-10% of the mixture by weight. The method is low in cost and easy to implement, and the prepared phase change energy storage material is highly stable.

The invention discloses a core-shell material. A core material of the core-shell material is selected from at least one of compounds having the molecular formulae as shown in formula (I) and formula (II); and the core-shell material is prepared by a method of a multilayer precursor. The core-shell material is applied to the field of a lithium ion battery as a positive electrode material, and has good air stability and safety performance while the high capacity advantage is exerted.

The invention discloses a preparation method of a magnetic nanometer carrier for immobilized enzyme. The carrier takes nano Fe3O4 as a core and alginic acid alkaline-earth metal salt as a shell; the carrier has the characteristics of being small in particle size, uniform in particle, good in monodispersity, large in specific surface area, good in chemical stability, strong in load capacity, good in biocompatibility, strong in magnetic response and the like. The preparation method of the magnetic nanometer carrier comprises the following steps: (1) preparing nano Fe3O4 in a reverse microemulsion system; (2) adding a sodium alginate solution to a reaction system, mixing evenly, and then adding an alkaline-earth metal salt solution; (3) after reaction is ended, obtaining the magnetic nanometer carrier by separation and purification. The preparation method of the magnetic nanometer carrier related to the invention is mild in reaction condition, simple in preparation, and controllable in carrier particle size and pore structure in the preparation process.

The invention provides a negative pole active material for a silicon-based lithium ion battery and preparation and application thereof. The negative pole active material of the silicon-based lithium ion battery comprises porous reduced graphite oxide and a porous silicon material coated with conductive polymerization attached to the pores of the porous reduced graphite oxide; the porous reduced graphite oxide has a pore diameter of 50 nanometres-2 micrometers; a conductive polymer coating layer has a thickness of 50 nanometres-200 micrometers; the porous silicon has a pore diameter of 100 nanometres-300 nanometres. The conductive polymer is one or more of polyaniline, polypyrrole and polythiophene. When the material is applied to a negative pole of the lithium ion battery, the material hasthe significant advantages of difficult pulverization, good stability, a large number of cycles and the like.

The invention provides an additive combination of li-ion secondary battery electrolyte; wherein, the combination has three different compounds. By adopting the additive combination provided by the invention, the circulation performance, the high-temperature storage performance, the low-temperature discharging performance and the ratio discharging performance of the battery are greatly improved as a whole, and the comprehensive performance of the battery is greatly improved.

The invention discloses a multifunctional infusion nursing apparatus for neurological department. The multifunctional infusion nursing apparatus comprises a supporting rod, wherein a handle is arranged on the supporting rod; a first sleeve is arranged at the lower side of the handle; a second sleeve is arranged at the lower side of the first sleeve; a third sleeve is arranged at the lower side of the second sleeve; a transverse rod is arranged at the right side of the third sleeve; an elastic arc-shaped fixed plate is connected to the right side of the transverse rod; a plurality of air vents are formed in the elastic arc-shaped fixed plate; arm fixing straps are arranged at the upper and lower ends of the right side of the elastic arc-shaped fixed plate; fasteners are arranged at the other ends of the arm fixing straps; the left end of the elastic arc-shaped fixed plate is fixed to the transverse rod; a fixing tray is arranged at the lower side of the third sleeve; and the supporting rod is fixed to a base by virtue of the fixing tray. The multifunctional infusing nursing apparatus provided by the invention is simple and convenient to operate; by adopting a liquid heating box, cold stimulation to a patient can be relieved, and meanwhile, medicine absorption can be accelerated and an internal heating material, instead of being frequently replaced, can be recycled for many times, so that a resource is saved; the normal implementation of infusion is guaranteed; and the multifunctional infusion nursing apparatus for the neurological department is convenient to use, resource-saving, time-saving and labor-saving.

The invention provides a method for preparing immobilized fructosyltransferase through ion exchange fibers. The weakly basic anion exchange fibers are used as a carrier to immobilize a liquid free fructosyltransferase to the carrier, the activity of the immobilized fructosyltransferase can be maintained for a long time, and the immobilized fructosyltransferase can be repeatedly used for a long time. The method comprises two pieces of technological content, namely the liquid free fructosyltransferase is prepared through biolysis and the immobilized fructosyltransferase is prepared through the ion exchange fibers. Fermentation cultivation is conducted on aspergillus oryzae to obtain a large amount of thallus, the thallus is washed, celluloses are used for dissolving the thallus, free enzyme fluid is extracted, and then the fructosyltransferase is immobilized through the ion exchange fibers. The activity of the obtained immobilized fructosyltransferase is larger than or equal to 180 U / g, the half-life period of the immobilized fructosyltransferase is larger than or equal to 40 times, the saccharose inversion rate is larger than or equal to 90%, and the content of fructo-oligose generated through the saccharose inversion is 55-60%. Compared with the public prior art, the method has the advantages that enzyme extraction is simple, operation time is short, enzymes can be easily recycled, the immobilization process is conducted without cross-linking agents, and the product quality and safety are high.

The invention discloses a sharing system of recyclable packaging boxes. The sharing system comprises recyclable packaging boxes, renting and return sites and an operation platform, wherein the recyclable packaging boxes comprise packaging box bodies as well as locking devices and tags mounted on the packaging box bodies; the locking devices comprise concave male buckles, convex female buckles anddisposable facing slips; the facing slips have sole codes and box body information; the renting and return sites comprise artificial renting and return sites and self-service renting and return cabinet sites; the renting and return sites further comprise intelligent terminals and sterilization devices in match; the intelligent terminals comprise mobile intelligent terminals and solid-source intelligent terminals; and the operation platform is adopted to achieve intelligent management on the recyclable packaging boxes according to data uploaded by the intelligent terminals. The sharing system has the advantages that the recyclable packaging boxes provided by the sharing system are safe, intelligent and environment-friendly, a complete renting system is established, the packaging cost can bereduced, packaging wastes can be reduced, and the sharing system is very practical when being applied to express logistics.

The invention belongs to the technical field of lithium batteries and provides a lithium ion power supply unit for starting of an automobile. The lithium ion power supply unit comprises a battery box, an upper cover and an electrical core arranged in the battery box, wherein the upper cover is provided with positive and negative terminals, the electrical core is composed of a plurality of lithium ion monomers in tandem and parallel connection, and an electrolytic capacitor is bridged over the positive and negative terminals. According to the lithium ion power supply unit for starting of the automobile, a lithium ion battery has good security and a great cycle index; the power supply unit is easy to charge, ripple waves generated by an electric generator are eliminated, and a good voltage stabilization effect is exerted; transient discharge current is great, vehicle voltage is allowed to be smooth and steady, and needs of starting of the automobile are met; high energy conversion efficiency is realized, fuel oil is saved, and emission is reduced.

The invention provides a production technology of a polypropylene building template, which is the technology for producing the building template by adopting waste plastics as the raw materials. The production technology comprises the steps of pretreating the raw materials, mixing the materials, and carrying out extrusion molding. The raw materials are treated based on a certain ratio and prepared into the product building template under a certain condition. The product building template has the characteristics that the construction quality is high, the building template can be recycled for a plurality of times, the cost is reduced, the benefit is increased, the energy conservation and environment protection are realized, and the residues can be recycled; and the product building template has a large market demand and wide prospect, and is an excellent substitute for steel templates, bamboo plywood and wood plywood.

The invention relates to a battery sorting method based on a charging and discharging curve and fuzzy clustering. The method comprises the following steps: acquiring respective charging and discharging curves of batteries to be sorted, and performing data sampling on each charging and discharging curve every N seconds to form complete cyclic sampling data and a feature vector set of a single battery so as to form a battery sample set matrix; substituting the battery sample set matrix into an FCM clustering algorithm; obtaining classification results. The battery packs are grouped by a sortingmethod, the decreasing trend of the attenuation rate of the cycle life of the battery packs is effectively inhibited, the consistency is higher than that of the battery packs formed without any sorting method, the cycle times of the sorted battery packs are more, and the consistency of the battery packs sorted by combining FCM and multiple parameters is superior to that of the battery packs sortedby OCV and internal resistance.

A system and method for identifying and manipulating logic analyzer data from multiple clock domains is presented. A logic analyzer receives debug data and determines whether the debug data is a full frequency data type, a half frequency data type, or a crossed data type. Once determined, the logic analyzer reconstructs the debug data such that debug condition-matching logic may process the reconstructed data in a full frequency domain. For half frequency data types, the logic analyzer adds masked data values to the data in order to reconstruct the data into to the full frequency domain before processing the data. For crossed data types, the logic analyzer reconstructs the data into its original format before processing the data in a full frequency domain.

The invention provides a weather-resisting polyvinyl chloride building plastic formwork and a preparation method. The weather-resisting polyvinyl chloride building plastic formwork is prepared from the following raw materials in parts by weight: 100 parts of polyvinyl chloride, 60-65 parts of calcium powder, 8-10 parts of wood powder, 6-8 parts of tribasic lead sulfate, 10-15 parts of chlorinated polyethylene resin, 2-3 parts of polymethyl methacrylate, 1-2 parts of polyethylene wax, 1-2 parts of resin chloroprene rubber adhesive, 15-18 parts of a polypropylene grafted butyl acrylate copolymer, 0.5-1 part of azodicarbonamide, 1-2 parts of sodium bicarbonate, 1-2 parts of stearic acid, 1-2 parts of oxidized polyethylene wax, 1-2 parts of an ultraviolet light absorber and 1-2 parts of phosphite ester. The preparation method of the weather-resisting polyvinyl chloride building plastic formwork comprises the following steps: heating a mixer to 90 degrees centigrade, adding the calcium powder and the wood powder, then orderly adding polyvinyl chloride, and finally adding the other raw materials; putting the mixed materials into a double-screw extruder, and extruding and plasticizing the materials into a colloidal material; molding the colloidal material in a mold of a mold pressing forming machine, and thus obtaining the weather-resisting polyvinyl chloride building plastic formwork.

The invention discloses a preparation method of a high-capacity lithium-rich ternary positive electrode material. The method comprises the following steps of weighing a lithium salt, a manganese salt,a cobalt salt and a nickel salt according to a stoichiometric ratio in a general formula zLi2MnO3.(1-z)LiMO2 and dissolving the weighed salts into deionized water to form a mixed salt solution; dissolving a chelating agent into the deionized water to form a chelating agent solution; slowly dropwise adding the chelating agent solution into the mixed salt solution in a back titration manner and mixing evenly; and adding an alkaline solution to adjust the pH value of the solution, heating the solution into a sol form in water bath, carrying out spray drying and then putting a product into a muffle furnace for sintering according to a certain sintering curve to obtain the high-capacity lithium-rich ternary positive electrode material, wherein z is smaller than 1 and greater than 0, M is MnxNiyCo(1-x-y), x is smaller than 1 and greater than 0 and y is smaller than or equal to 0.6 and greater than 0. The high-capacity lithium-rich ternary positive electrode material is prepared by using a one-step sol method; the preparation method is simple, mild, environment-friendly and efficient; and the synthetic product has relatively high specific capacity and relatively good rate capability.

The invention relates to the field of energy, and provides a lithium battery. The lithium battery comprises a positive electrode, a negative electrode, a diaphragm and an electrolyte; the positive electrode is prepared from the material of lithium iron phosphate; the surface of the lithium iron phosphate is covered with a graphite layer, wherein the thickness of the graphite layer is equal to the thickness of 1-10 carbon atoms; and the electrolyte comprises the following components in parts by weight: 48-60 parts of lithium hexafluorophosphate, 30-35 parts of lithium bis(oxalate)borate, 0.1-1.2 parts of carbodiimide, 0.3-2 parts of methylphenyl ether or halogenated alkane, 0.1-1 parts of ortho-position or para-position dimethoxy substituted benzene, 0.1-4 parts of halogenated-alkyl phosphate, 2-8 parts of chain carbonate, 1.5-7 parts of cyclic carbonate and 0.5-0.7 parts of acrylamide. The lithium battery is high in electrical conductivity and cycling performance. The invention also provides a power utilization apparatus which comprises the lithium battery provided by the invention, so that the power utilization apparatus is long in service life.

The invention discloses a method of simple catalysis to prepare a spiro-1,3-dioxoindanpyrane derivative and a catalyst for preparing same and belongs to the technical field of chemical material preparation. In the preparation method, the molar ratio of ninhydrin, malononitrile and a 1,3-cyclohexanedione compound is 1:1-1.2:1, wherein the molar percentage of the catalyst is 3-6% by mole of the ninhydrin. The volume quantity of a reaction solvent, an ethanol water solution, is 4-7 times of the molar weight of the ninhydrin. Reaction temperature is 74-80 DEG C and reaction time is 8-24 min. After the reaction is finished, the reaction product is cooled to room temperature and is subjected to suction filtration. A filter residue is washed through an ethanol water solution and is vacuum-dried to obtain the spiro-1,3-dioxoindanpyrane derivative. Compared with the prior art, the catalyst is low in use amount and has more recycling utilization times. The whole preparation process is simple and convenient in operations and has high green degree, so that the method is easy to apply in industrial large-scale production.

The invention provides a synthetic method of p-tert-butylbenzaldehyde. A liquid-phase oxidation method is used, p-tert-butyltoluene as a raw material, oxygen as an oxidizing agent, N-hydroxyl phthalimide as an initiator and acetonitrile as a solvent are used under the action of a catalyst for reacting for 7 hours at the temperature of 70 DEG c under the magnetic stirring rotating speed of 200r / minso as to obtain the p-tert-butylbenzaldehyde. The selected catalyst is a Ni-loaded microporous molecular sieve, and preparation raw materials comprise a nickel salt, a molecular sieve and deionized water; the microporous molecular sieve is used as a carrier for loading of an active component by an impregnation method to prepare the catalyst containing the active component nickel, the catalyst hasrelatively high selectivity and activity, the conversion rate of the raw material in the reaction for preparing the p-tert-butylbenzaldehyde by the liquid-phase oxidation reaches 30.6%, the selectivity of the target product reaches 77.2%. Compared with other catalysts in the prior art, the catalyst has the advantages that the selectivity is obviously improved.

The invention relates to the technical field of drilling fluid separation equipment, and discloses a separation vibrating screen for drilling fluid. The separation vibrating screen comprises a base, ascreen frame is movably mounted at the top of the base, a placement plate is fixedly mounted at the top of the screen frame, a vibration excitation device is fixedly mounted at the top of the placement base, a screen device is fixedly mounted on the front surface of an inner cavity of the screen frame, a communicating hose fixedly communicates with the bottom of the screen device, and a negativepressure chamber is fixedly mounted on the front surface of the inner cavity of the base. According to the separation vibrating screen for the drilling fluid, a spiral pneumatic blade, an injector head and an eccentric block are arranged in the vibration excitation device and are matched with one another, external compressed air enters the outer side cavity through the air inlet, and the sprayinghead sprays the compressed air to the outer surface of the spiral pneumatic blade so that the device provides a vibrating source for the vibrating screen through the compressed air, a special vibrating motor does not need to be arranged, and energy is saved.

The invention discloses an environment-friendly type agricultural product baking machine. The environment-friendly type agricultural product baking machine comprises a body and a blower, wherein the body is provided with a baking chamber and a draft chamber; an auxiliary blowing mechanism and a hollow heat supply seat are arranged in the baking chamber; a moisture removal port and a moisture removal cylinder are arranged on the top surface of the body; a moisture removal adjusting device is arranged on the moisture removal cylinder; a side partition plate and a middle partition plate are arranged in the draft chamber; the blower is mounted in a front chamber; a heating element is mounted in a back chamber; the hollow heat supply seat communicates with the back chamber; a side port and a side seal plate are arranged on the side partition plate; a return air control device for controlling the side port to be opened or closed is arranged on the side seal plate; an air inlet and a front seal plate are arranged on the front side surface of the body; and an inlet air control device for controlling the air inlet to be opened or closed is mounted on the front seal plate. Compared with theprior art, by adjusting the air amount of the moisture removal port, the side port and the air inlet, the baking machine disclosed by the invention can adapt to a baking process required by shiitake mushrooms and also adapt to baking processes of different agricultural products, so the baking machine has the advantages of wide application range, energy saving, environmental protection and high baking speed.

The invention discloses a high-strength formwork free of layer separation and a method for manufacturing the high-strength formwork. The high-strength formwork and the method have the advantages that the length directions of battens a are consistent with the growth direction of wood, the height directions of battens b are consistent with the growth direction of the wood, accordingly, sufficient adhesive steeping and mechanical bracing effects can be realized, a core is extremely high in mechanical property in the vertical direction and the horizontal direction and is low in deformation, layer separation phenomena inside the machined core can be prevented, the high-strength formwork is high in modulus, and buckling deformation of the formed formwork can be prevented; the mechanical properties of the formwork can be improved by the aid of continuous fiber reinforcement composite surface layers, the high-strength formwork is light, waterproof and anticorrosion, is high in strength and recycling frequency, and can be easily released from forms, the recycling frequency of the high-strength formwork can reach a hundred at least, accordingly, the service life of the building formwork can be greatly prolonged, and the single-service cost can be reduced.

The invention discloses a quinoline derivative, a synthesis method of the derivative and a catalyst for synthesis, and belongs to the technical field of organic chemical synthesis. The molar ratio of 2-chloro-3-quinoline formaldehyde and beta-dione in synthesis reaction is 1:1, the molar amount of an acidic ionic liquid catalyst is 6-12% of the used 2-chloro-3-quinoline formaldehyde, the volume amount of a reaction solvent methanol aqueous solution in ml is 7-10 times of the molar amount of the 2-chloro-3-quinoline formaldehyde in mmol, the reflux reaction time is 7-15 min, cooling is performed to room temperature after the reaction is finished, suction filtration is performed, and the filter residues are washed with methanol and vacuum-dried to obtain the quinoline derivative. Compared with synthetic methods using other catalysts, the method has low use amount of the catalyst, reusability without treatment, high raw material utilization rate, simple and convenient operation of the whole synthesis process and the like, and is advantageous for large-scale industrial application.

The invention discloses an additive manufacturing product and powder treating system and a working method thereof. According to the technical scheme, the system is characterized by comprising a powdercleaning cabinet, wherein a powder cleaning table is arranged in the powder cleaning cabinet, a forming barrel is placed on one side of the lower portion of the powder cleaning table, used old powderis contained in the forming barrel, a vibrating screen used for screening the old powder or novel powder is arranged on the other side of the lower portion of the powder cleaning table, a material receiving barrel used for receiving screened powder is arranged below the vibrating screen, a dust collection cabinet communicating with the powder cleaning cabinet is arranged outside the powder cleaning cabinet, a dust collection device is arranged in the dust collection cabinet, a powder recycling barrel and a powder mixing barrel are further arranged outside the powder cleaning cabinet, and a powder mixing device for fully mixing the novel powder and the old powder is arranged in the powder mixing barrel. According to the system and the method, arrangement of the powder barrels is redesigned, the old powder and the novel powder need to be screened through the vibrating screen, coarse particles are prevented from entering mixed powder, purity and more recycling times of the mixed powder are guaranteed, and the surface quality of printing-formed parts is guaranteed.

The invention relates to a crop harvesting ploughing tool comprising a supporting rack connected to a tractor. A transferring case is mounted on the supporting rack; the transferring case is connected with a transmission shaft; the transmission shaft is connected with a tractor power output via a universal joint; the transferring case is connected with an eccentric wheel via a connection shaft; the eccentric wheel is connected with a vibration rod; a soil-lifting plough is fixed under the supporting rack; a front soil vibration shifting fork is hinged behind the soil-lifting plough; the front soil vibration shifting fork is hinged with a back soil vibration shifting fork; the front soil vibration shifting fork is hinged with a vibration rod; the vibration rod is connected with a second vibration rod; and the second vibration rod is hinged with the back soil vibration shifting fork. The crop harvesting ploughing tool can be installed on an elevated tractor; crops of two ridges or more can be harvested; the soil vibration shifting forks can vibrate in a waveform; and the back soil vibration shifting fork has more period and amplitude changes.

The invention discloses a method for preparing pyrano [4,3-b] pyran derivatives by basic ionic liquid catalysis, and belongs to the technical field of preparation of chemical materials. The molar ratio of aromatic aldehyde to 4-hydroxy-6-methylpyrane-2-ketone to an active methylene compound in preparation reaction is 1 to 1 to 1; the molar weight of the basic ionic liquid catalyst is 15%-20% of the molar weight of used aromatic aldehyde; the volume dose of reaction solvent water on the basis of milliliter is 10-14 times that of the aromatic aldehyde on the basis of millimole; the reflux reaction time is 15-45 minutes; the product is cooled to a room temperature after reaction is ended; suction filtration is carried out; filter residues are washed and dried in vacuum through dimethylformamide to obtain a pyrano [4,3-b] pyran derivative. Compared with the preparation method employing other ionic liquids as solvents, the method has the characteristics of being low in ionic liquid dosage, high in raw material utilization rate and the like; water is utilized as a reaction solvent; the operation in the overall preparation process is simple and convenient; and industrial large-scale application is facilitated.