871 results about "Pretreatment method" patented technology

The invention discloses a water quality prediction method based on machine learning and an SWAT model, and belongs to the technical field of water environment simulation and water quality early warning. The method comprises the steps that S1, hydrology, water quality, meteorology, land utilization types, pollution sources and spatial elevation multi-temporal data are collected from multiple channels in a drainage basin, and noise reduction, normalization and missing value filling preprocessing methods are adopted for original data; s2, performing sensitivity analysis on the nonlinear relationship between the SWAT model parameters and the output by adopting SVR, and screening out key parameters with remarkable influence; s3, on the basis of the water quality monitoring data, constructing a water quality time sequence prediction model by adopting an LSTM model; and S4, constructing a self-learning mechanism based on the LSTM and the SVR model, and retraining the model by adjusting a learning time window and regularly utilizing latest data. The method is excellent in the aspects of model efficiency, prediction precision and application adaptability, and has remarkable engineering application value and popularization potential.

The invention discloses a chicken manure crude protein content detection model construction method, a chicken manure crude protein content detection system and a detection method, relates to the technical field of bioinformatics, solves the problems of high cost, serious pollution and low efficiency of an existing chicken manure crude protein content detection technology, and improves the accuracy of chicken manure resource application. The obtained sample set comprises visible-near infrared reflection spectrum and crude protein content of the chicken manure; carrying out pretreatment on the visible-near infrared reflection spectrum by adopting a plurality of pretreatment methods; screening out an optimal preprocessing method and a corresponding preprocessing spectrum by using a partial least square regression model; obtaining a characteristic wave band by using a plurality of characteristic selection methods; and based on the crude protein content and the characteristic wave band, constructing and screening an optimal chicken manure crude protein content detection model. The method provided by the invention is suitable for detecting the content of crude proteins in chicken manure by using manure resources.

The invention relates to the technical field of low-temperature studs and bolts, and discloses a low-temperature stud steel hardenability optimization treatment method which comprises the steps of S1, a pretreatment method, S2, quenching method optimization, S3, tempering method optimization, S4, a post-treatment method and S5, a performance verification method. According to the method, the low-temperature impact stability is remarkably improved, the low-temperature impact energy of the material at about-100 DEG C can stably reach 35 J or above by accurately controlling the proportion of alloy elements and optimizing the heat treatment process (for example, the tempering temperature is increased to 640 DEG C or above and the heat preservation time is prolonged), the low-temperature impact energy is improved by about 20%-30% compared with a traditional process, and the problem that the low-temperature impact performance of the wire rod fluctuates is thoroughly solved; and the service safety in a low-temperature environment is ensured.

The invention discloses a chicken manure crude protein content detection model construction method, a chicken manure crude protein content detection system and a detection method, relates to the technical field of bioinformatics, and solves the problems that an existing chicken manure crude protein content detection technology is serious in pollution in the detection process, and a spectral analysis technology is serious in information redundancy during detection, high in cost and poor in model stability. The sample set comprises visible-near infrared reflection spectrum and crude protein content of chicken manure; obtaining three spectral indexes corresponding to the visible-near infrared reflection spectrum, the MSC pretreatment spectrum and the SNV pretreatment spectrum, and screening out the optimal wavelength position and the corresponding three spectral indexes; constructing a data set by using the three spectral indexes and the crude protein content, and performing fitting through multiple fitting modes; evaluating the plurality of fitting equations, and screening out an optimal fitting equation and a corresponding pretreatment method and wavelength position as a chicken manure crude protein content detection model. The method provided by the invention is suitable for detecting the content of crude proteins in chicken manure by using manure resources.

The invention discloses an intelligent carbon anode quality detection system, particularly relates to the field of electrolytic aluminum, and comprises a data acquisition module, a data preprocessing module, a data analysis module and a comprehensive judgment module. According to the method, a full-process data acquisition system covering raw materials, forming, roasting and appearance is constructed, accurate acquisition of multi-source data is realized by using equipment such as an X-ray fluorescence spectrometer and a hydraulic sensor, the problem of dispersion of traditional detection data is solved, and the detection accuracy of the multi-source data is improved through multi-stage pretreatment methods such as outlier elimination, sliding window filtering, temperature compensation and wavelet noise reduction. Dimension difference and sensor noise interference are effectively eliminated, and data reliability is improved. A multi-level evaluation model composed of a raw material comprehensive index, forming energy density, roasting maturity and appearance integrity is innovatively established, and intelligent comprehensive evaluation and accurate grading management and control of the carbon anode quality are achieved in combination with a dynamic weighting comprehensive quality index formula and a four-level grading mechanism.

The invention discloses a pretreatment method for efficiently extracting calcium in shrimp and crab shells. The pretreatment method comprises the following steps: carrying out microwave treatment on the shrimp and crab shells until the weight is constant, rehydrating for 10 minutes in a water bath at 90 DEG C, carrying out microwave treatment until the weight is constant, crushing, mixing with an acetic acid solution, stirring, centrifuging, and measuring the calcium concentration. According to the method, through microwave-rehydration-secondary microwave pretreatment, the carapace structure is destroyed, the contact area of organic acid and calcium is increased, the calcium recovery rate is increased, the treatment time is shortened, the energy consumption is reduced, the universality of raw materials is enhanced, comprehensive utilization of resources is facilitated, and the method is environmentally friendly and economical.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a pretreatment method for improving the leaching rate and the carbon adsorption rate of high-sulfur-arsenic gold ore. Comprising the following steps that the high-sulfur-arsenic gold ore is ground and then prepared into ore pulp; a green oxygen activating agent and hydrogen peroxide are sequentially added into the ore pulp, oxidation pretreatment is conducted on the high-sulfur-arsenic gold ore, ore pulp activating liquid is formed, and the green oxygen activating agent is a mixture of calcium oxide, sodium persulfate and soluble bivalent iron salt; and adding a gold leaching agent into the ore pulp activation solution, adjusting the pH value of the ore pulp to 9-12, carrying out stirring gold leaching treatment, filtering to obtain a leaching solution, and then adding activated carbon to adsorb and extract gold. According to the method, a stronger oxidation environment is provided, meanwhile, the residual concentration of arsenate radicals in the solution is effectively reduced, the leaching rate of gold and the adsorption rate of activated carbon are greatly increased, excellent oxidation performance and environment friendliness are shown, and a more sustainable high-sulfur-arsenic gold ore pretreatment process is provided.

This invention discloses a spectral preprocessing method and related equipment for online coal quality detection using multispectral coupling. The method includes: simultaneously acquiring LIBS and NIRS spectra of raw coal using an online coal quality detection device; screening the effectiveness of the synchronized LIBS and NIRS spectra; identifying the defocusing amount of each set of synchronized LIBS and NIRS spectra and assigning a corresponding defocusing amount label to each set of spectra; correcting the defocused spectra according to the defocusing amount label using a spectral correction method to obtain corrected LIBS and NIRS spectra, and then fusing them to obtain a corrected fused spectrum; analyzing the LIBS spectrum, NIRS spectrum, and fused spectrum using quantitative analysis methods, and calculating the fixed carbon content. This invention's LIBS and NIRS spectral fusion overcomes the limitation of a single spectrum only characterizing atomic or molecular information, enabling a complete characterization of the chemical information of the coal sample and achieving simultaneous and accurate analysis of multiple coal quality indicators.

The invention mainly relates to the technical field of underground engineering safety, and provides a tunnel rockburst pretreatment method and system based on multi-physics field parameters while drilling in order to improve the rockburst risk recognition and pressure relief effect through the multi-physics field parameters in the deep hard rock tunnel drilling process. The core of the method is that a surrounding rock three-dimensional geologic model is established based on multi-source physical field parameters in the surrounding rock while-drilling process; establishing a rockburst risk index prediction model of the surrounding rock three-dimensional geologic model based on an improved D-S evidence theory to calculate a rockburst risk index; and determining simulated pressure relief parameters according to the rockburst risk indexes, performing simulated pressure relief, judging whether the change rate of the multi-source physical field parameters meets the set requirements or not, if so, performing pressure relief according to the simulated pressure relief parameters, otherwise, re-determining the pressure relief parameters, and performing pressure relief until the change rate of the multi-source physical field parameters meets the set requirements.

The invention belongs to the technical field of hydrometallurgy, and particularly relates to a pretreatment method for enhancing peroxide to improve the leaching rate of high-sulfur-arsenic gold ore. Comprising the following steps that the high-sulfur-arsenic gold ore is ground and then prepared into ore pulp; an oxidizing agent is added into the ore pulp, oxidation pretreatment is conducted on the high-sulfur-arsenic gold ore under the catalytic action of ultraviolet light, and ore pulp activation liquid is formed; and the pH of the ore pulp activating solution is adjusted to 9-12, a gold leaching agent is added into the ore pulp complexing solution, and stirring gold leaching treatment is conducted. According to the method, efficient oxidation of sulfide and arsenide is achieved under the mild condition through the synergistic effect of photocatalysis and chemical oxidation, the leaching rate of gold is remarkably increased, compared with a conventional peroxide oxidation method for pretreatment, the leaching rate can be increased by 10%-35%, and meanwhile the agent use amount and environmental pollution are reduced.

The invention provides a method for improving the interface performance of an aramid fiber laminate composite material through high-temperature pretreatment and a preparation process of the aramid fiber laminate composite material, and relates to the field of performance improvement of composite materials. Comprising the following steps: S1, heating aramid fibers at 150-300 DEG C for 3-15 minutes, and immediately taking out the aramid fibers; s2, fully and uniformly coating epoxy resin on the aramid fiber obtained in the step S1; and S3, carrying out molding treatment on the aramid fiber obtained in S2 to obtain the aramid fiber composite material with improved interface performance. The simple high-temperature pretreatment method is adopted, the number of polar functional groups on the surface of the aramid fiber is increased, the resin impregnation degree of the aramid fiber and the bonding performance between fiber-resin interfaces are improved, and the interlaminar shear strength of the composite material is greatly improved.

The invention discloses a method for determining and analyzing primary and secondary elements in dolomite and magnesite based on ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry), and relates to the technical field of determination and analysis of the primary and secondary elements, the method comprises the following steps: obtaining determination samples of the dolomite and the magnesite, pretreating the determination samples, obtaining spectral line interference conditions of each element based on the determination samples, and determining the spectral line interference conditions of the elements based on the spectral line interference conditions; the method comprises the following steps: pre-processing measured data, drawing a calibration curve of each element, obtaining the interference condition of the calibration curve of each element, and carrying out ICP-AES measurement on the pre-processed measured data to obtain a characteristic spectral line. According to the method, the source and the influence degree of the interference spectral line are determined by analyzing the spectral line interference condition, then targeted measures are adopted for correction, and meanwhile, concentration measurement deviation caused by chemical interference, physical interference, ionization interference and other factors is found by evaluating element concentration interference factors, so that the accuracy of the concentration measurement is improved. And correction is carried out by means of optimizing a sample pretreatment method, adjusting instrument working conditions and the like, so that the reliability and the stability of the analysis method are improved.

The invention provides a ship ballast water system fault diagnosis model establishment method, belongs to the technical field of ship ballast water systems, and adopts a random noise data enhancement and maximum and minimum value standardization preprocessing method to improve data quality. Designing a CNN-I nformer hybrid architecture, fusing a probability sparse self-attention mechanism and distillation operation to extract time sequence features, and establishing a double-layer game optimization framework including an adaptive spiral flight sparrow search algorithm to perform joint optimization on model hyper-parameters; a softmax classifier is adopted to realize accurate identification of five states of sea chest filter filth blockage, ballast water pump bearing wear, valve blockage, pipeline leakage and system normal operation, and generalization ability and practicability of the model are ensured through an early stop strategy and multi-index performance evaluation. The technical problems that the ship ballast water system fault diagnosis precision is insufficient and the calculation complexity is too high are solved.

The invention discloses a pretreatment method for increasing the yield of anaerobic fermentation methane of a lignocellulose material, and belongs to the technical field of high-efficiency anaerobic fermentation methane production of organic solid waste. The method comprises the following steps: (1) crushing straws; (2) mixing the straw powder and deionized water according to a mass ratio of 1: (19-21), stirring at a rotating speed of 120-180r / min, treating for 22-26h, fully and uniformly mixing, adjusting the pH value of the system to 3.4-3.7, adding 0.08-0.12 wt% of cellulase according to the mass of the straw, and carrying out enzymolysis at 49-51 DEG C for 2-4d to obtain an enzymatic hydrolysate; (3) yeast pre-fermentation: inoculating 4-6% v / v activated angel high-activity dry yeast into the enzymatic hydrolysate in the step (2) for anaerobic pre-fermentation, wherein the pre-fermentation time is 16-20 hours; and (4) anaerobic fermentation for methane production: adding 20-30% v / v of introduction sludge into the fermentation system in the step (3), and carrying out anaerobic fermentation for methane production, wherein the fermentation temperature is 36-38 DEG C. Compared with the prior art, the method has the advantages of being high in adaptability, short in treatment period, good in economic benefit, free of environmental pollution and the like, and has certain guidance and inspiration effects on engineering of producing methane from straw.

The invention belongs to the technical field of coating breeding, and particularly relates to a pretreatment method for iron powder coating breeding. Comprising the following steps: (1) mixing granular urea, calcium superphosphate and potassium chloride to obtain granular fertilizer; (2) dissolving granular fertilizer in water to prepare a granular fertilizer aqueous solution, soaking the rice seeds in the granular fertilizer aqueous solution for 3-5 hours, taking out the rice seeds, spreading the rice seeds in a shade place, and airing the rice seeds for 10-20 minutes to obtain fertilizer-soaked seeds; (3) mixing iron powder, granular fertilizer and bentonite in a powerful mixer for 5-10 minutes to obtain an iron fertilizer mixture, and rolling the iron fertilizer mixture through a high-pressure roller mill to obtain a roller-milled material; the rice seeds are coated with iron powder, so that the dead weight of the seeds is increased, the floating rate and the bird damage loss rate are greatly reduced, and the purpose of direct seeding of the rice seeds can be achieved.

The invention discloses a micro-fine particle gold ore normal-pressure alkaline leaching pretreatment method based on sodium percarbonate reinforcement, and belongs to the field of precious metal metallurgy. The method comprises the following steps: adding an oxidizing agent sodium percarbonate in batches under the condition that air is filled into ore pulp, starting to monitor the oxidation potential and the pH value of a reaction system after adding, judging that the reaction reaches the end point when the sudden drop amplitude of the oxidation potential of the ore pulp within one hour is greater than or equal to 30mV and the pH value is increased by 0.3-0.5 unit, and stopping aeration to finish pretreatment; in the segmented oxidation process, the oxidation potential is controlled within the range of + 520 mV to + 550 mV by dynamically adjusting the air charging rate. According to the basic technical scheme, the gold leaching rate reaches 86.01%, the gold leaching rate reaches up to 88.92% through the optimized technical scheme, and the utilization rate of gold ore resources is remarkably increased.

The invention discloses a heterogeneous Fenton-like catalyst, a preparation method, a reaction device and a pretreatment method thereof. According to the catalyst, high-iron-content ash is used as a base material, porous magnetic particles of 3-5 mm are prepared through biomass reduction, magnetic separation enrichment, bonding granulation and roasting, the specific surface area is 200-300 m < 2 > / g, and the porosity is 70-80%. The device is of a closed vertical three-area structure, a pipeline mixer and a tangential nozzle are adopted to form rotational flow, and a gas collecting hood collects waste gas and is provided with a backwashing loop from bottom to top. During operation, H2O2 is added according to 1-1.5 times of the COD (Chemical Oxygen Demand) of inlet water under the nearly neutral condition that the pH value is 5-7, and the catalyst stays for 30-60 minutes, so that high-salt high-chlorine refractory organic wastewater can be efficiently degraded, iron mud can be reduced, backwashing and recycling are easy, the operation cost is reduced, and the method has engineering popularization value and is stable and reliable in operation.

The present invention provides a pretreatment method for determining the stable isotope ratio of non-exchangeable hydrogen in acetic acid, belonging to the field of stable isotope analysis of foods. The pretreatment method comprises the following steps: adding a reaction reagent to a vinegar sample extract to replace the carboxyl hydrogen in the acetic acid with the exchangeable hydrogen to achieve isotope exchange equilibrium. The present invention can be used to simply and rapidly determine the isotope ratio of non-exchangeable hydrogen in acetic acid in vinegar products and can be used in research and applications for detecting the authenticity or adulteration of vinegar products.

The invention discloses a treatment system and method for high-temperature waste gas of a gas-based shaft furnace. The treatment system comprises a gas-based shaft furnace reactor, a top gas heat exchanger, a process gas preheater and a process gas quench tower, a high-temperature waste gas outlet of the gas-based shaft furnace reactor is sequentially communicated with a top gas heat exchanger, a process gas preheater and a process gas quench tower; the process gas quench tower comprises a tower body, a vortex gas inlet device is arranged at the inner lower part of the tower body, a structural filling layer is arranged at the inner middle part of the tower body, and a high-pressure water spray cooling device is arranged at the inner upper part of the tower body. According to the process gas quench tower, the vortex gas inlet device and the vortex technology are adopted as an effective pretreatment mode, and by optimizing the gas inlet flowing state of waste gas, the temperature of the waste gas can be effectively reduced and the heat energy loss can be reduced under the condition that the gas flow speed is ensured; and due to the application of the structural filling layer, the heat transfer efficiency between the waste gas and the cooling medium is improved by increasing the heat exchange surface area, and the cooling effect is further improved.

A method of pretreatment of a sample containing a cell for mass spectrometry, including contacting the cell with a first acidic solution containing an organic acid; and extracting a cytoplasmic component of the cell by heating the cell in contact with the first acidic solution.

The invention relates to the technical field of monocrystalline silicon raw material pretreatment, in particular to a monocrystalline silicon raw material impurity pretreatment method based on a thermal migration effect, which comprises the following steps: (1) silicon block pretreatment: ultrasonically cleaning a polycrystalline silicon block to obtain a cleaned polycrystalline silicon block; (2) in an inert gas environment, carrying out gradient heating on the cleaned polycrystalline silicon block to migrate impurities so as to obtain a heat-treated polycrystalline silicon block; (3) carrying out directional gas purging on the heat-treated polycrystalline silicon block to obtain a purged polycrystalline silicon block; and (4) cooling and post-processing: cooling the blown polycrystalline silicon block to below 100 DEG C along with the furnace, and taking out the polycrystalline silicon block. Compared with direct acid pickling, the method has the advantages that the metal impurity removal rate is increased by 30% through the specific monocrystalline silicon raw material impurity pretreatment method based on the thermal migration effect, and the method has a good application prospect.

The invention provides a method for recovering scandium from scandium-containing lithium slag and a pretreatment method of the scandium-containing lithium slag. The method for recovering scandium from the scandium-containing lithium slag comprises the following steps: mixing the scandium-containing lithium slag with concentrated sulfuric acid, and heating and roasting to obtain a roasted product; the roasted product is subjected to water leaching, and scandium-containing leaching liquid and leaching residues are obtained; the scandium-containing leachate is extracted, and a scandium-containing organic phase and raffinate are obtained; washing the scandium-containing organic phase to obtain a purified scandium-containing organic phase and a washing solution; carrying out reverse extraction on the purified scandium-containing organic phase, and filtering to obtain a reverse extract; the reverse extract is subjected to acid dissolution, and a scandium-containing acid solution is obtained; adding oxalic acid into the scandium-containing acid solution for precipitation, filtering to obtain scandium oxalate precipitation, and roasting to obtain scandium oxide.

The invention relates to a reverse osmosis membrane pollution control method based on green biological scale inhibition, which is especially suitable for reverse osmosis membrane pollution treatment in an industrial wastewater zero discharge system. The method comprises the following steps: regulating and controlling the composition of organic components of inlet water through a sand filtration pretreatment unit, and directly interfering the nucleation and crystallization processes of inorganic scaling on a membrane surface by utilizing naturally enriched microbial communities and extracellular polymeric substances thereof in a sand filtration process without adding a fungicide or a chemical scale inhibitor, so as to form a loose and reversible pollution layer structure. The method effectively reduces the scaling rate of inorganic salts such as calcium carbonate and the like, inhibits membrane surface biological pollution, delays compaction of a pollution layer, improves the membrane flux retention rate, prolongs the membrane operation cycle and reduces the cleaning frequency. Compared with an existing traditional physical or chemical pretreatment method, the natural scale inhibition effect of an ecological system in the sand filtration unit is fully utilized, and the method has the remarkable advantages of being low in operation cost, environmentally friendly, high in adaptability and the like.

The invention relates to the technical field of iodide content detection, in particular to a method for determining radiochemical purity and iodine content of sodium iodide capsules for diagnosis by HPLC (High Performance Liquid Chromatography), which comprises the following steps: setting chromatographic conditions, and connecting a radioactive flow detector and an ultraviolet detector in series; preparing a disodium hydrogen phosphate solution, a glucose solution, a vitamin C solution, a first control solution, a potassium iodate solution, a second control solution, a carrier solution, a first sample solution, a second sample solution, a negative control solution and a test solution; and determining the radiochemical purity and iodide content of the first sample solution and the second sample solution in three batches based on the chromatographic conditions and the determination standard. According to the method, test parameters such as capsule sample analysis time, a pretreatment mode and a sample size are optimized, the radiochemical purity of the capsule is accurately determined, and the iodide content is controlled, so that the problem that main components cannot be accurately quantified and potential radioactive impurities cannot be detected by a traditional diagnosis sodium iodide [131I] capsule determination method is solved.

The invention relates to the field of biogas energy utilization, and discloses a biogas intelligent regulation and control storage and use method, which comprises the following steps: carrying out preliminary impurity screening on original biogas, buffering pressure by using a gas buffering device, detecting component preset pressure and temperature range, and carrying out graded pressurization and segmented cooling to obtain biogas. Mixing with a hydrating agent and an accelerant to generate a gas hydrate for storage, judging whether to start a decomposition process or not according to stock and demand data, and establishing a hydrating agent closed-loop recovery mechanism. According to the system, pretreatment means such as impurity screening, pressure buffering, staged pressurization and staged cooling are combined with a decomposition process dynamic regulation and control and hydration agent recycling mechanism based on real-time data, so that whole-process intelligent management of biogas from purification, storage to gas supply is realized, the hydration reaction efficiency and the stability of a storage system are improved, and the energy consumption is reduced. The continuity and flexibility of gas supply are guaranteed, and meanwhile, the operation cost and the resource consumption are reduced.

The invention provides a surface pretreatment method of an aluminum alloy, which comprises the following steps: polishing an LDH growth surface by using abrasive paper, washing the surface of the aluminum alloy by using deionized water and absolute ethyl alcohol in sequence, putting the washed aluminum alloy into absolute ethyl alcohol to ultrasonically remove surface impurities, and treating the surface of the aluminum alloy by using acid to obtain the aluminum alloy. The method can weaken the adverse effect of an intermetallic compound when LDH grows on the surface of the aluminum alloy, and then a ZnAl-LDH film layer is generated on the surface of the treated aluminum alloy by adopting a hydrothermal method. By means of the treatment method, part of intermetallic compounds can be dissolved, a complex film is formed on the surface, the potential difference of different areas of the surface is reduced, the adverse effect of the intermetallic compounds when LDH grows on the surface of the aluminum alloy can be weakened, an LDH film layer with better corrosion resistance is generated, and when a corrosive medium invades the film layer, the corrosion resistance of the film layer is improved. The metal substrate is effectively prevented from being damaged by a corrosive medium through chloride ion absorption and a physical barrier effect, so that corrosion of chloride ions to the substrate is reduced, and the corrosion resistance of the substrate is improved.

The invention discloses a sample pretreatment method for measuring organic components in titanium tetrachloride and a measurement and analysis method, and belongs to the technical field of detection and analysis of the organic components in inorganic materials. The sample pretreatment method and the measurement analysis method comprise the following steps: carrying out liquid-liquid extraction on a titanium tetrachloride sample to be detected by adopting a combined reagent, fully reacting, standing for layering to obtain a clear, transparent, non-emulsified and clear-interface two-phase system, separating and collecting a subnatant liquid phase to obtain a solution to be detected for detecting and analyzing the organic components in titanium tetrachloride; and sending the solution to be detected to an organic analysis instrument for organic component detection and analysis by adopting a direct sample injection mode. The method provided by the invention can effectively solve the influence of deposition blockage, matrix effect, highly corrosive volatile gas of HCl and the like caused by high-concentration inorganic components such as Ti < 4 + >, Cl <->, H < + > and the like in TiCl4 on a detection instrument and a determination result.

The invention discloses a pretreatment method for improving water-retaining property and tenderness of low-temperature slowly-cooked chicken, and relates to the technical field of food processing.The pretreatment method comprises the steps that a chicken raw material is prepared, and unfreezing, surface drying and finishing treatment are conducted; the method comprises the following steps: soaking chicken in a pre-cooled weak acid solution to preliminarily relax a protein structure; transferring the chicken into a pre-cooled weak alkaline solution, promoting protein to be fully hydrated, and establishing an electrostatic repulsion network; immersing chicken in a precooled polysaccharide solution, and permeating to form a thermostable hydrophilic protective layer; and draining the chicken, performing vacuum packaging, and performing low-temperature slow cooking with precise temperature control. According to the method, the low-temperature slowly-cooked chicken can keep a stable hydration structure in the cooking process through a method for regulating protein and constructing an interface protection layer in stages, so that the water-retaining property, tenderness and flavor fusion degree of a finished product are improved.

The invention relates to the technical field of oxidation treatment of powder metallurgy products, and discloses a surface oxidation treatment device for high-airtightness powder metallurgy products, which comprises a pretreatment mechanism, one end of the pretreatment mechanism is fixedly connected with a steam treatment furnace, and a conveying mechanism is mounted between the pretreatment mechanism and the steam treatment furnace; a powder metallurgy product assembly is conveyed on the conveying mechanism; the pretreatment mechanism comprises a first machine body, an outer shell, a ventilation shell, a vacuum assembly and a first steam assembly, the outer shell is connected to the upper side of the first machine body, and the ventilation shell is fixedly connected to the inner side of the outer shell. According to the active pretreatment method, the closed cavity is vacuumized firstly to form negative pressure, then low-temperature steam is injected, and the steam is forcibly and rapidly permeated into all the deep holes of the powder metallurgy product through the pressure difference. The problem of non-uniform permeation caused by obstruction of residual air in pores in traditional direct steam treatment is fundamentally solved.

This invention belongs to the field of bile acid detection technology, and discloses a sample pretreatment method for determining the content of bile acid subtypes and its application. The pretreatment method includes the following steps: S1, acidifying the sample to be tested with an acidifying agent to a pH of 2-4 to obtain an acidified sample; S2, eluting the acidified sample onto a mixed-mode anion exchange column to obtain an eluent; S3, evaporating the eluent and reconstituted with a rehydration solution to obtain the test sample. The test sample obtained by this pretreatment method can effectively eliminate or compensate for matrix interference when used for targeted analysis of bile acid subtypes by LC-MS / MS, thus effectively improving detection sensitivity.