173results about How to "Efficient process" patented technology

The invention provides an automatic SRAF exposure development suppression method and device, a medium, a program product and a terminal, and aims to optimize an SRAF placement area when an interference pattern is detected in an initial exposure pattern through a multi-round iterative optimization technical means, and when a new exposure pattern meets a preset termination condition, the iterative optimization operation is ended, so that the SRAF exposure development is suppressed. Therefore, the problems of time waste and flow complexity caused by redesigning the SRAF placement rule in the traditional method are solved. According to the method, the original spatial position of the SRAF is kept, the enhancement effect on the resolution of the main graph is guaranteed to the maximum extent, and the definition and precision of the graph are improved, so that the production efficiency is improved, the manufacturing process is simplified, and a more convenient solution is provided for practical application.

The invention relates to the technical field of hydroelectric generators, in particular to a three-dimensional flow field load reconstruction method based on reinforcement learning of a gated circulation unit, which comprises the following steps of: establishing a Python-based finite element secondary development platform, and realizing finite element simulation and obtaining a finite element simulation result; fusing a plurality of simulation characteristic indexes extracted from the finite element simulation result by using a multi-scale model fusion algorithm to obtain a finite element simulation result evaluation index, and optimizing simulation parameters; constructing an initial three-dimensional flow field load reconstruction model based on reinforcement learning of a gated circulation unit, and training the initial three-dimensional flow field load reconstruction model by using the optimized simulation parameters; and based on the trained three-dimensional flow field load reconstruction model, obtaining a reconstructed three-dimensional flow field load. By means of the reconstruction method, automatic simulation of finite element software and full-automatic optimization iteration of a parameter decision and reinforcement learning reconstruction network in the three-dimensional flow field load reconstruction process of the hydroelectric generating set component can be achieved.

The invention particularly relates to a gas station oil gas recovery online monitoring system, method and device and a medium, the monitoring system comprises a sensor network, an edge controller and a cloud computing monitoring platform, and the sensor network is used for collecting working parameters at key nodes in the oil gas recovery process. And the edge controller is used for performing preliminary data processing based on the working parameters to obtain oil gas recovery performance parameters and refueling equipment early warning information. And furthermore, the cloud computing monitoring platform is used for acquiring the oil gas recovery performance parameter sent by each edge controller in the gas station, and performing multi-dimensional data analysis based on each oil gas recovery performance parameter to obtain an oil gas recovery multi-dimensional monitoring result. By executing multi-dimensional data analysis, abnormal conditions in the oil and gas recovery process can be found and fed back in time, efficient oil and gas recovery work is ensured, meanwhile, potential fault points can be recognized in advance, the downtime and maintenance cost caused by faults are reduced, and the stability and reliability of the oil and gas recovery process are improved.

The invention relates to the technical field of infrared optical materials, and particularly discloses a large-size high-resistance infrared silicon single crystal and a preparation method thereof. The doping concentration of cobalt oxide in the large-size high-resistance infrared silicon single crystal is 10 ppm to 100 ppm, and the atomic concentration of phosphorus in the large-size high-resistance infrared silicon single crystal is 2 * 10 < 13 > / cm < 3 > to 6 * 10 < 13 > / cm < 3 >. The oxide of transition metal cobalt and phosphorus impurities are doped into the infrared silicon single crystal, carriers of cobalt and phosphorus and carriers of impurities such as boron and oxygen generate a recombination effect, so that the concentration of free carriers in the silicon single crystal is reduced, and the absorption coefficient of the doped silicon single crystal is relatively small; the infrared transmittance of the silicon single crystal in a medium wave band can be obviously increased, the resistivity can reach 600 omega.cm or above, and the use requirement of the infrared silicon single crystal in a high-performance infrared optical system can be met.

The invention discloses a preparation method of a sodium alginate fiber biological material fiber with a hollow structure and a sodium alginate fiber.The preparation method comprises the following steps that 101, CaCl2 particles are dissolved in deionized water and fully stirred, and a CaCl2 / H2O core layer spinning solution is prepared; step 102, dissolving sodium alginate in deionized water, heating to improve the solubility of the sodium alginate in the deionized water, and fully stirring to obtain an SA / H2O cortex spinning solution; and step 103, respectively extruding the SA / H2O skin layer spinning solution and the CaCl2 / H2O core layer spinning solution into a CaCl2-removed coagulating bath through a coaxial needle at the speeds of 200 [mu] L.min <-1 > and 200 [mu] L.min <-1 >, and aging to obtain the hollow fiber. According to the preparation method, a coaxial spinning process is adopted, and the problems of fluid fracture and the like caused by drafting instability can be effectively avoided. Hollow fibers are used for replacing solid rod-shaped fibers, the process is efficient, convenient, energy-saving and environment-friendly, the experiment repeatability is high, a high-voltage electric field and toxic substances are not involved in the preparation process, and damage to biological tissues is avoided.

The invention discloses an intelligent operation and maintenance management system, and relates to the technical field of system operation and maintenance management, the intelligent operation and maintenance management system comprises a data acquisition module, a data processing module and a data analysis module, the data acquisition module collects performance data from a network device, a Windows server and an application program by using a simple network management protocol, a WMI interface and an API interface, and the data processing module processes the performance data and analyzes the performance data. The data processing module is used for establishing a unified technical monitoring standard and realizing comprehensive real-time monitoring and data analysis of a technical environment by utilizing an autoencoder anomaly detection algorithm, and rapidly finding and responding to anomaly and fault, so that the technical environment is monitored and monitored in real time; and the data analysis module is used for setting an intelligent alarm and early warning rule based on an abnormal detection result, immediately sending out early warning information once a problem is detected, and presenting an analysis result in a graphical mode, so that operation and maintenance personnel are assisted to intuitively understand a system state and an operation and maintenance effect, and efficient operation and maintenance work is ensured.

The invention provides an ultraviolet disinfection device for producing nursing pads, which relates to the technical field of ultraviolet disinfection, and comprises a disinfection box, wherein a central column is fixed at the inner center of the disinfection box, a feeding inlet is opened on one side of the disinfection box, and a feeding outlet is opened on the other side of the disinfection box, and a conveyor belt is arranged outside the feeding inlet and the feeding outlet of the disinfection box, a nursing pad body is placed on the surface of the conveyor belt, and a pushing assembly is arranged on the top of the conveyor belt on one side of the feeding outlet. Compared with the prior art, the nursing pad for feeding inlet is clamped by a translation assembly and a clamping assembly, and is transformed from a planar shape to a vertical shape, and circulates around the annular disinfection box, and the two sides of the nursing pad are irradiated by ultraviolet lamp columns on the inner wall of the disinfection box and the outer wall of the central column to improve the disinfection effect, and then the nursing pad is sent out from one side of the feeding outlet. The overall process is efficient, with less human intervention, and is suitable for cyclic disinfection in a production workshop.

The embodiment of the invention provides a public opinion information recommendation method and device, a storage medium and a terminal, and the method comprises the steps: obtaining one or more pieces of public opinion information related to a target public opinion theme to form a public opinion information set after the target public opinion theme is determined; obtaining one or more of correlation dimension information, source dimension information and propagation dimension information of each piece of public opinion information in the public opinion information set; and according to the scoring rule corresponding to each piece of dimension information, determining the score of each piece of dimension information, and calculating the value score of each piece of public opinion information in combination with the weight of each piece of dimension information. And performing public opinion information recommendation according to the value score sequence of all public opinion information in the public opinion information set. By applying the method, the public opinion information can be automatically analyzed and screened from multiple dimensions, the efficiency and authority of public opinion information acquisition are improved, and real-time updating is supported, so that enterprises or governments and the like can acquire the latest public opinion information in real time and quickly take countermeasures, and potential business risks are avoided.

The invention discloses PCB (printed circuit board) through hole plugging resin which is prepared from the following raw materials in parts by weight: 35-100 parts of epoxy resin composition, 5-15 parts of curing agent, 1-10 parts of curing accelerator and 0.1-5 parts of assistant. By adopting the combination of the bisphenol A epoxy resin, the bisphenol F epoxy resin and the trifunctional epoxy resin, the prepared hole plugging resin is easy to plug holes, not easy to sag and excellent in hole plugging performance. The thermosetting resin composition is used for permanently filling the through hole in the printed circuit board, has the properties of low viscosity, easiness in hole filling, good sagging resistance and high glass transition temperature, not only can meet the requirements of an existing vacuum hole filling machine, but also can meet the hole filling requirements on high efficiency and high cost performance in a complex printed circuit board.

The invention discloses a quartz fiber with an yttrium oxide coating and a preparation method of the quartz fiber, and belongs to the field of preparation of wave-transparent ceramics. Aiming at the problem that the performance of the existing quartz fiber is reduced at a high temperature, the invention provides the preparation method of the quartz fiber with the yttrium oxide coating, which comprises the following steps: impregnating the quartz fiber by using yttrium oxide sol, and drying and sintering the impregnated quartz fiber to obtain the quartz fiber coated with the yttrium oxide coating on the surface; the preparation process of the yttrium oxide sol comprises the following steps: sequentially adding a coordination agent and a stabilizer into a yttrium nitrate solution, stirring and dissolving to form a mixed solution, adding a pH regulator to adjust the pH value of the mixed solution to 7-8, heating to a target temperature, and cooling to obtain the yttrium oxide sol. The yttrium oxide coating covers the surface of the quartz fiber, so that the high-temperature sintering resistance of the quartz fiber can be greatly improved; the preparation process of the yttrium oxide sol is simple in technology and low in cost, the prepared yttrium oxide sol is good in stability and can be better attached to the surface of the quartz fiber, and the dipping effect is improved.

The invention relates to the field of terminal control, in particular to an angle measurement method and device and a storage medium. The angle measurement method provided by the invention is applied to first reference equipment, and comprises the following steps: based on communication connection between target equipment and second reference equipment, determining a plurality of phase measurement values of signal interaction between the target equipment and each reference equipment under a plurality of signal frequencies; based on the plurality of phase measurement values, respectively determining a signal phase change estimation value corresponding to each signal frequency, and obtaining a plurality of signal phase change estimation values; determining a distance difference between the target device and the two reference devices based on the plurality of signal phase change estimated values; and determining deflection angles between the target equipment and the two pieces of reference equipment based on the baseline length and the distance difference between the two pieces of reference equipment. The purpose of high-precision angle measurement can be achieved under the condition that other measurement sensors do not need to be added.

The invention relates to the technical field of phosphorus chemical solid waste treatment, and particularly discloses a reverse-direct flotation desilicication and impurity removal combined process for phosphogypsum. According to the process, C12-18 alkyl dimethyl ethyl benzyl ammonium chloride is used as a reverse flotation reagent, a mixture of R-NH2 or hydrochloride thereof and R-OSO3Na according to a certain proportion is used as a direct flotation reagent, R in the direct flotation reagent is alkyl and is the same as the alkyl in the reverse flotation reagent, and through the one-reverse-one-direct flotation process, the content of the R in the reverse flotation reagent is reduced, and the content of the R in the reverse flotation reagent is reduced. And various impurities such as silicon, organic matters and fluorine in the phosphogypsum can be synchronously removed. After flotation, the yield of concentrate can reach 75%, the grade of CaSO4. 2H2O is 97.7% or above, and the desilicication rate reaches 75% or above. The method is simple in process, efficient and low in cost.

The invention relates to a copper-iron bimetallic Fenton-like catalyst and a preparation method and application thereof.The preparation method comprises the steps that copper salt, iron salt and gamma-Al2O3 are mixed in deionized water and stirred through a mechanical stirring rod, and a mixed steeping liquor is obtained; carrying out spray drying on the mixed impregnation liquid on a spray dryer, and preliminarily removing moisture to obtain a precursor of the copper-iron bimetallic Fenton-like catalyst; and calcining the precursor of the copper-iron bimetallic Fenton-like catalyst in a tubular furnace to obtain the copper-iron bimetallic Fenton-like catalyst. The catalyst provided by the invention has the characteristics of easy recovery, high catalytic activity and the like, and solves the problems of low catalytic efficiency of an iron-based catalyst and difficult recovery of a copper-based catalyst in the prior art.

The invention belongs to the field of heavy metal complex wastewater treatment, and particularly relates to a non-metal doped titanium-based metal monatomic electrode for decomplexing complex-state heavy metals and a preparation method and application thereof, the non-metal doped titanium-based metal monatomic electrode comprises a titanium substrate, and non-metal atoms and metal monatomic which are respectively loaded on the surface of the titanium substrate; the non-metal atoms are selected from one or more of phosphorus, boron and sulfur; the metal single atoms are selected from one or two of iron and cobalt. Compared with the prior art, the problems that in the prior art, an electrochemical anode material is poor in activity and insufficient in stability when breaking complex-state heavy metal are solved, the strong bonding interaction between an inherent oxide layer on the surface of the titanium-based material and a metal monatomic site is utilized, and metal monatomic is fixed to the surface of the material; meanwhile, nonmetal is introduced to regulate and control an electronic structure of metal, so that the metal site stability and decomplexing performance are improved.

The invention discloses a fresh water ecosystem health monitoring method and system. The method comprises the following steps: acquiring a historical remote sensing image, and acquiring a physical index; acquiring historical ground measured data, and extracting chemical indexes and biological indexes; establishing a training set and a test set based on each index; a classification machine learning model is selected to construct a sub-model for each index, the training set is used as input for training, and a plurality of water quality evaluation sub-models are obtained; performing accuracy analysis on each water quality evaluation sub-model, calculating relevancy and stability between different models, and obtaining fusion weights of the corresponding water quality evaluation sub-models; combining all the water quality evaluation sub-models based on the fusion weight to construct a comprehensive water quality evaluation model; and performing fresh water ecological water quality evaluation through the comprehensive water quality evaluation model to generate an evaluation report. According to the invention, accurate evaluation of fresh water ecological water quality is realized by combining remote sensing and ground measured data.

The invention provides a whole-process continuous production system for an aliphatic epoxy diluent. The invention further provides a whole-process continuous production process of the aliphatic epoxy diluent. The invention further provides an aliphatic epoxy diluent which is prepared by the production process. According to the full-process continuous production system and process for the aliphatic epoxy diluent, through continuous process design and device optimization, the problems of high labor intensity and large product quality fluctuation in traditional intermittent method epoxy diluent production are effectively solved, the production efficiency and the product quality stability are improved, and the production cost is reduced. And the method has great application value and market competitiveness.

The invention provides a process and system for synthesizing a bismaleimide compound, and relates to the technical field of chemical synthesis, and the process comprises the following steps: (1) amidation reaction; (2) ring-closure dehydration reaction; (3) recovering the organic solvent; (4) a toluene thermal washing process; (5) a cooling crystallization process; (6) alkali washing process; (7) washing with hot water; and (8) drying. The process provided by the invention is high in production efficiency, the synthesized bismaleimide product is high in yield and purity, and compared with the prior art, the process is a clean production process in which the solvent can be recycled, no waste liquid is generated, the environment-friendly requirement is met, and the process has great environmental benefits, social benefits and economic benefits.

The invention discloses a method for extracting tobacco flavor components, which comprises the following steps: distillation-dry distillation, collection and elution recovery: the distillation-dry distillation comprises the following steps: adding tobacco into a dry distillation device, preheating the dry distillation device, introducing superheated steam into the dry distillation device, and collecting the tobacco flavor components; heating the dry distillation device until the temperature in the kettle is 100-450 DEG C so as to simultaneously perform distillation and dry distillation on the tobacco; the collection comprises collection of distillates distilled in the whole distillation-dry distillation process; the elution recovery comprises the following steps: adding ethanol into the distillate, placing the distillate in refrigeration equipment, carrying out alcohol precipitation, carrying out coarse filtration, and finally carrying out membrane filtration to obtain a solution containing tobacco aroma components. According to the method, the process steps are further optimized, so that the production process is simplified, meanwhile, the yield of the tobacco aroma components is increased, and the pollution to the environment is reduced.

The invention provides a nursing personnel electronic shift-change system and a processing method thereof, which are used for establishing a set of nursing personnel electronic shift-change system by utilizing a modern information technology, so that the nursing personnel electronic shift-change system can be quickly and conveniently switched under the condition that a standardized communication mode is met. The system can well meet the efficient and accurate high-quality handover requirements of nursing personnel for the handover work, and provides a series of more complete and intelligent matching schemes from the detail aspect, thereby promoting the high-quality clinical nursing work. The system comprises a user terminal and a server, wherein the server is further configured with a database; the user terminal displays a visual interface to the shift-change nursing personnel; the user terminal receives shift change content input by the shift change nursing personnel in the standardized communication mode; the server receives the shift change content; the server checks and confirms the shift change content; and the server generates a shift change report based on the audited and confirmed shift change content, and the shift change report is archived and is received and used by the shift pick-up nursing personnel.

The invention discloses a mold for measuring the low-pressure casting solidification rate of aluminum alloy and an implementation method of the mold, and the method comprises the following steps: 1, installing a thermocouple, and calibrating the thermocouple; 2, defining experimental parameters, and adjusting a mold cooling system; 3, recording temperature data in real time, and analyzing and evaluating the temperature data; 4, cutting the standard mechanical sample, and carrying out mechanical property test and microstructure characterization; and 5, feeding back to production according to an experimental result, optimizing an experimental process, and improving the product quality. The temperature distribution in the casting can be accurately measured in real time, so that the solidification rate is indirectly controlled and measured, and the quality and the production efficiency of the casting are remarkably improved by monitoring the solidification process in real time.

The invention discloses an in-situ preparation method of a nano-silver-antibacterial peptide conjugate agar antibacterial film. The in-situ preparation method comprises the following steps: dissolving pectin in an alkali solution to obtain a pectin alkali solution; adding nisin and silver salt into the pectin alkali solution, and mixing to obtain a colloidal solution; agar and an emulsifier are added into the colloidal solution, and the nano-silver-antibacterial peptide conjugate agar antibacterial film is obtained after mixing. Biomacromolecule pectin is used as a reducing agent and a stabilizing agent, pectin molecules contain a large number of carboxyl groups, the carboxyl groups can be ionized under the alkaline condition to form carboxyl anions, the reducing capacity of the pectin molecules is improved, silver ions can be reduced into silver atoms, and therefore synthesis of nano-silver is promoted; in addition, the alkaline condition can improve the reaction rate, improve the dispersity of the nano-silver and improve the stability of the nano-silver. The colloidal solution contains a nano silver-antibacterial peptide conjugate.

This invention belongs to the field of cosmetic raw material preparation technology, specifically relating to a method for preparing a low-odor Xinjiang Lithospermum extract, its product, and its application. The method includes: raw material pretreatment: drying and pulverizing Xinjiang Lithospermum raw material to obtain pretreated material; first-stage extraction: loading the pretreated material into a supercritical fluid extraction device, adding a composite entrainer for extraction, and collecting the first fraction in a first separator; second-stage extraction: collecting a second fraction rich in naphthoquinone components in a second separator; and post-treatment: concentrating the second fraction and removing the alcohol solvent to obtain the low-odor Xinjiang Lithospermum extract. This invention can separate and discard most of the odor-causing volatile components in the raw material under mild conditions in the first stage, and then efficiently extract the core active substances of naphthoquinone in the second stage, achieving a significant reduction in the odor of the extract and a significant improvement in its sensory quality.

The invention belongs to the technical field of metal separation, and particularly relates to a deep eutectic solvent, a preparation method and application thereof, and a method for selectively extracting lithium from a lithium battery positive electrode material. According to the deep eutectic solvent provided by the invention, nearly 100% selective leaching of lithium is realized in an extremely short time, and Ni, Co and Mn are almost not leached, so that the bottleneck that the rate and the selectivity are difficult to obtain at the same time in a traditional method is broken through; and the process conditions are mild and efficient, are far superior to the traditional process and are more suitable for practical industrial application, and the energy consumption and material consumption are remarkably reduced.

The invention relates to a method for integrating supercritical CO2 extraction (SCE) and a microcapsule technology to be applied to citrus combined medicinal materials, the effective component is essential oil, three factors including pressure (P), temperature (T) and time (t) are optimized, and then microencapsulation is carried out. The extracted essential oil contains a plurality of pharmacological active ingredients and has a unique fragrant smell. According to the essential oil extraction optimization process of the combined medicinal material, a fitted equation with a very high correlation coefficient is obtained through optimization fitting of a total extraction rate equation, and the essential oil extraction optimization process of the combined medicinal material has a great promotion effect on essential oil extraction of the citrus combined medicinal material in a Chinese patent medicine or health-care product preparation process. The extracted essential oil of the citrus combined medicinal material can be wrapped in a multi-layer structure through a microencapsulation process, and component volatilization and oxidation are prevented.

A cosmetic treatment method includes: spraying, toward skin or hair: an atomized medicinal agent in which a medicinal agent containing a predetermined active ingredient is atomized; and fine water that is uncharged and has a particle size of less than or equal to 50 nanometers. Therefore, the sprayed fine water enters the skin or hair to contribute to maintenance of moisturization, and at the same time, forms a route through which the active ingredient permeates, thereby promoting the permeation of the active ingredient; therefore, the permeability of the active ingredient can be more appropriately improved.

The invention discloses a lactobacillus delbrueckii subsp. Bulgaricus CCFM1520 for transforming curcumin to produce tetrahydrocurcumin to relieve nervous anxiety, and belongs to the technical field of microorganisms. The lactobacillus delbrueckii subsp. Bulgaricus CCFM1520 screened by the invention has the capability of converting curcumin, and can utilize curcumin and generate tetrahydrocurcumin. The invention further provides a synbiotic preparation prepared from the lactobacillus gasseri CCFM1481 and curcumin, the synbiotic preparation can be used as an anti-fatigue functional medicine, the individual behavioral memory level can be improved, the imbalance of body neurotransmitters (DA, 5-HT and NE) can be slowed down, the expression of body neuroprotection related genes (BDNF, TrkB, DRD1 and TH) can be improved, and the synbiotic preparation has a huge application prospect.

The application discloses a fishing device used in the technical field of phosphating, which comprises a first hook, a second hook and a third hook, the first hook is connected with the second hook and the third hook, the third hook is connected with the first hook and the second hook, the top of the first hook, the second hook and the third hook is connected with a traction part, the traction part is used for pulling the first hook, the second hook and the third hook, when the force applied on the first hook by the traction part is greater than the force applied on the second hook and the third hook, the first hook vertically rises, the second hook and the third hook downwardly incline, and the second hook and the third hook are fixed from the side or the bottom of the hanging object by the downward inclination of the second hook and the third hook.

The present application discloses a viscous liquid filling machine for online cleaning by using reset time, aiming at solving the problem that the feeding pipeline cleaning of the existing viscous liquid filling machine needs to be stopped, cannot be cleaned online, and is prone to cause pipeline blockage and delay production due to untimely cleaning. The present application is based on a following type filling machine, a scraping ring is arranged in the hose connecting the raw material bin and the quantitative cylinder, the movement gap of the filling mechanism in the reset section of the annular electric slide rail is utilized, the scraping ring is driven to move up and down along the hose by the cable driven by the first and second electric winding mechanisms, the viscous material adhered to the inner wall of the hose is scraped off, and the online cleaning of the hose is realized. The cleaning process does not need to stop, does not occupy production time, and does not need to be washed with water, avoiding the problem that the material is diluted by water, cleaning is more thorough, effectively preventing pipeline blockage, and improving the filling production efficiency.

The present invention discloses a bag-smoothing assembly for a packaging machine with separated inner and outer packaging bags, comprising a bracket, a lifting assembly is arranged above the bracket, an elastic bag-smoothing mechanism is connected to the bracket below through a tension adjustment assembly, a telescopic connection mechanism is also arranged inside the bracket, an exhaust pipe is arranged above the telescopic connection mechanism and at the top of the bracket, a bag-supporting assembly plate is arranged below, and the bag-supporting assembly plate and the elastic bag-smoothing mechanism jointly open the bag opening. The beneficial effects of the present invention are: the elastic bag-smoothing mechanism can adjust the action range of the frame, which is convenient for applying packaging bags of different models; the spring pressure plate and the bag-supporting assembly plate can jointly open the inner bag opening, and can jointly straighten the inner bag opening upward; the lifting assembly includes a pulley lifting mechanism and a cylinder lifting mechanism, which realizes the stable up and down movement of the bracket, and avoids excessive force when the cylinder lifting mechanism is instantly started and stopped, thereby damaging the packaging bag.

The present invention provides a thiamine sulfate crystal and an extraction method thereof, and relates to the technical field of thiamine sulfate purification, and the extraction method comprises the following steps: thiamine thiosulfate is oxidized by hydrogen peroxide to obtain an oxidation liquid, and the oxidation liquid is added into an organic solvent for crystallization and separation to obtain the thiamine sulfate crystal; the organic solvent comprises at least one of methanol, ethanol and acetone. According to the extraction method, the specific organic solvent is adopted to crystallize the thiamine sulfate, high-purity thiamine sulfate crystals can be extracted from the aqueous solution oxidized by thiamine thiosulfate, the purity can reach 99.70% or above, and the process is simple, efficient and suitable for industrial production.