342 results about "Sodium nitrite" patented technology

The invention discloses a novel synthetic method for 5-phenyl tetrazole, which includes the following steps: firstly performing acid neutralization to hydrazine hydrate; then adding mixing solution formed by cyanobenzene, water and ethyl alcohol to generate phenyl aminoguanidine salt; adopting sodium nitrite for diazotization to obtain nitrine amidine under the acidic condition; obtaining 5-phenyl tetrazole crude product through closed loop under the alkaline condition; obtaining 5-phenyl tetrazole acceptable product through adopting ethyl alcohol for refining. The method has the advantages of simple technology, simplicity in operation and high product yield.

The invention relates to the technical field of cement mortar compositions, and particularly discloses a double-component anti-freezing early-strength slurry and a preparation method and application thereof. The double-component anti-freezing early-strength slurry provided by the invention is composed of a component A and a component B in a weight ratio of 25: (4-10), the component A is prepared from the following components in parts by weight: 250 to 280 parts of Portland cement, 90 to 100 parts of admixture, 145 to 165 parts of sand and 6.4 to 8.4 parts of water reducing agent; and the component B comprises the following components in parts by weight: 8-10 parts of a sodium nitrite antifreeze agent, 50-58 parts of a reinforcing aid, 32-40 parts of anhydrite, 240-270 parts of an admixture, 155-175 parts of sand and 4.1-6.1 parts of a water reducing agent. By utilizing the technical scheme, the prepared double-component anti-freezing early-strength slurry has the advantages of rapid development of early compressive strength and stable growth of later compressive strength under different ultralow temperature conditions.

The invention belongs to the field of lithium ion battery material preparation, and provides a preparation method of low-impurity battery grade iron phosphate, which comprises the following steps: dissolving titanium dioxide ferrous sulfate in water to obtain a solution A, adjusting the pH value of the solution A to 3.0-4.0, reacting, and carrying out solid-liquid separation to obtain a clear liquid; adjusting the pH value of the clear liquid, and then mixing the clear liquid with sodium nitrite to obtain a solution B; adding the solution B into a reaction kettle, introducing compressed oxygen until the pressure in the kettle body is 5-15 bar, reacting until the pressure in the kettle body is reduced to a constant value, and carrying out solid-liquid separation to obtain a purified iron source solution; preparing iron phosphate dihydrate by taking the purified iron source solution and a phosphorus source as raw materials through a precipitation method; and calcining the iron phosphate dihydrate to obtain the low-impurity battery-grade iron phosphate. The preparation method is simple and feasible in process, low in cost, wide in source of required raw materials, good in safety, low in cost, easy to realize large-scale production, good in impurity removal effect and low in iron loss, and the Mn content of the battery-grade iron phosphate prepared from the impurity-removed ferrous sulfate can be as low as 10 ppm or below.

The invention provides a preparation method of 4-fluoro-3, 5-dimethylphenylhydrazine hydrochloride, which comprises the following steps: salifying 4-fluoro-3, 5-dimethylaniline serving as a substrate with concentrated hydrochloric acid, reacting with sodium nitrite to prepare a diazo solution, reducing the diazo solution into corresponding phenylhydrazine by using alkaline sodium sulfite as a reducing agent system, and reacting the 4-fluoro-3, 5-dimethylphenylhydrazine hydrochloride with the diazo solution to prepare the 4-fluoro-3, 5-dimethylphenylhydrazine hydrochloride. And acidizing the 2, 5-dimethyl phenylhydrazine to obtain corresponding phenylhydrazine hydrochloride. According to the preparation method, sodium sulfite which is low in cost and easy to obtain is used as a reducing agent, the defects that metal residues are high, the environment is prone to being polluted and the raw material cost is high due to the fact that a metal reducing agent is adopted when phenylhydrazine hydrochloride is prepared in the prior art are overcome, the reaction is completed in a water phase, no organic solvent is adopted, and the concept of green chemistry is met; and the problems of complicated post-treatment and easy pollution caused by the adoption of an organic solvent can be effectively avoided.

The invention relates to a pickling process of a cold-rolled strip, and belongs to the technical field of metal surface treatment. The acid pickling process comprises the steps of surface pretreatment, sand blasting treatment, acid pickling, water washing, passivation and the like. In the surface pretreatment, an oil removing agent and a rust removing agent are used for removing oil stains and rust stains on the surface of the cold-rolled strip, and then deionized water is used for cleaning. 200-mesh brown aluminum oxide and high-purity nitrogen are used for blowing and removing solid impurities in the sand blasting treatment. And pickling is carried out by using a 180-220g / L hydrochloric acid solution at 60-80 DEG C for 3-10 minutes. And after washing, drying at 110 DEG C in a nitrogen atmosphere. In the passivation step, a sodium nitrite passivation solution with the mass fraction of 30-50% is sprayed under the nitrogen atmosphere, and a laser drying method is used for drying. In addition, the invention further provides a preparation method of the oil removal agent and the rust removal agent and specific parameters of sand blasting treatment, nitrogen purging, acid pickling, spraying and laser drying.

The invention belongs to the technical field of food processing, and particularly relates to fermented beef jerky and a preparation method thereof. The preparation method of the beef jerky comprises the following steps: (1) removing fascia and fat from fresh cattle hind leg meat, washing with clear water, and cutting into meat slices; (2) adding table salt, glucose, white granulated sugar and sodium nitrite into the sliced meat, uniformly mixing, adding a fermentation inoculant which comprises staphylococcus calcaratus, pediococcus acidilactici, bifidobacterium bifidum and Witzia ciliaris, and fermenting; and (3) after fermentation, drying and cooling to obtain the fermented beef jerky. Specific strains are selected to form a fermentation inoculant for fermentation, and the prepared fermented beef jerky is high in free amino acid and soluble peptide content, low in nitrite residual quantity, uniform red brown in color and slightly bright in surface, and belongs to high-quality beef jerky.

The invention discloses a nano phase change heat storage material with high decomposition temperature as well as a preparation method and application thereof, and belongs to the technical field of mixed molten salt energy storage materials. The nanometer phase change heat storage material is composed of 99 wt% of low-melting-point mixed molten salt and 1 wt% of SiO2 nanometer particles. The low-melting-point mixed molten salt is composed of potassium nitrate, sodium nitrite and sodium nitrate according to the mass ratio of 53: (10-30): (17-37). The low-melting-point and high-decomposition-temperature nanometer phase change heat storage material with the melting point being 150-175 DEG C and the decomposition temperature being 660-723 DEG C is prepared by combining the mixed molten salt composed of potassium nitrate, sodium nitrite and sodium nitrate according to the specific dosage ratio with SiO2 nanoparticles, the melting point of the phase change material is low, energy consumption can be effectively reduced, and the energy consumption is reduced. And the composition has good decomposition temperature, melting latent heat and other thermophysical properties.

The invention discloses a continuous kettle type nitromethane production process, and relates to the technical field of basic chemical raw material synthesis and flow chemical reaction process control, which comprises the following steps: quantitatively and continuously pumping a temperature-regulated sodium nitrite mixed solution into a raw material mixer in a closed-loop automatic control mode through a variable-frequency feeding pump matched with a mass flow meter; synchronously, quantitatively and continuously pumping dimethyl sulfate into the raw material mixer in a closed-loop automatic control manner by matching a feeding pump with a stop valve and a mass flow meter, and uniformly mixing the two raw materials in the raw material mixer according to the stoichiometric molar ratio of the dimethyl sulfate to the sodium nitrite, according to the tandem type segmented design, each reaction kettle can be subjected to customized temperature field control and heat transfer design specially aiming at the special thermodynamic and dynamic requirements of the reaction stage where the reaction kettle is located, the heat transfer efficiency of the whole system is greatly improved, and due to the fact that reaction heat is taken away timely and accurately, the heat transfer efficiency is greatly improved. And a by-product generation path induced by local abnormal high temperature is effectively restrained.

The invention discloses delayed coagulation type super-early-strength quick-hardening mortar and a preparation method thereof, and relates to the technical field of building materials, a shell-core structure targeted modified early strength agent is designed, a staged dry-wet mixing technology is adopted, seabed in-situ curing is combined, cooperation of mortar delayed coagulation construction and super-early-strength development is achieved, and the construction efficiency is improved. According to the present invention, with the design of the targeted modified early strength agent, the surface delayed coagulation shell and the core early strength core structure are formed through the grafting reaction of the sodium nitrite and the hydroxyl carboxylic acid monomer, and the 15-25% accurate grafting rate control is matched, such that the antagonism problem of the traditional early strength agent and the delayed coagulation agent can be solved, and the deep sea open caisson grouting temporary support requirement can be met; in the deep sea environment, the delayed coagulation shell can guarantee a construction window of 75-105 min, the requirement for long-distance grouting of the seabed is met, deep sea high pressure can trigger the delayed coagulation shell to be broken, the core early strength core rapidly activates cement to be hydrated, and the mortar can rapidly form the requirement for rapid bearing of the open caisson temporary support with enough strength.

The invention discloses a water-based compensation sodium source sodium ion battery positive pole piece and a preparation method thereof. Mixing a positive active material, a conductive agent, a water-based binder, a water-soluble sodium supplement agent and a solvent to obtain positive slurry; wherein the water-soluble sodium supplement comprises sodium nitrite, sodium oxalate and sodium citrate; the solvent is water; and coating the surface of a current collector with the positive electrode slurry to prepare the positive electrode plate. Deionized water is used for replacing a traditional organic solvent to serve as a pulping solvent, and dual-function optimization is achieved by adding a specific water-soluble sodium supplementing agent. The sodium supplementing agent is uniformly distributed in the pole piece through a dissolution-recrystallization mechanism, and an efficient sodium ion pre-compensation system is formed. According to the method, the production cost and the energy consumption are remarkably reduced, the structural degradation of the positive active material in a water system environment can be effectively inhibited, irreversible sodium loss caused by formation of a first-week solid electrolyte interface (SEI) of a negative electrode is counteracted through a sodium source compensation mechanism, and the method has remarkable environmental friendliness and industrial application value.

The invention belongs to the field of textile dyeing and finishing, and relates to a dyeing method capable of regulating and controlling in-situ assembly of dye molecules through cellulose fiber graft modification. The dyeing method comprises the following steps: soaking a cellulosic fiber textile in a 4-beta-hydroxyethylsulfonyl sulfate aniline-2-sulfonic acid aqueous solution for reaction, washing with water, drying, soaking in a hydrochloric acid aqueous solution, adding a sodium nitrite aqueous solution for reaction, adding urea, washing with water, and drying to obtain the cellulosic fiber textile. Soaking in a coupling component aqueous solution containing a coupling component, sodium hydroxide and sodium carbonate for reaction, alternately washing with hot water and cold water, and drying to obtain the dyed textile. The dyeing method is mild in condition, dye hydrolysis is avoided, the dye uptake and the dyeing fastness are improved, and the dye utilization rate is high; high temperature and a large amount of inorganic salt or auxiliaries are not needed, the dye is directly generated and fixed in the fiber, energy consumption is remarkably reduced, and waste water treatment pressure is reduced.

The invention discloses a polyfunctional group synergistic reverse osmosis membrane and a preparation method thereof, and relates to the technical field of new materials and membrane separation. The polysulfone porous base membrane is sequentially soaked in a water phase monomer solution and an oil phase monomer solution, the polyamide reverse osmosis membrane is prepared through interfacial polymerization, sulfonic acid groups are introduced in the process, and water transfer channels are increased; soaking in an aminobenzene sulfonic acid aqueous solution, and introducing a benzenesulfonic acid group to improve the hydrophilicity of the reverse osmosis membrane; then treating with a sodium nitrite aqueous solution, and carrying out diazotization coupling reaction on the surface, so as to improve the crosslinking degree of the polyamide separation functional layer. The reverse osmosis membrane is cleaned by using a sodium sulfite aqueous solution, and an unreacted diazo group is replaced by a sulfurous acid group, so that the surface stability of the reverse osmosis membrane is improved. The preparation method provided by the invention is easy to control and simple in process, and the reverse osmosis membrane obtained by the preparation method has a synergistic effect of polyfunctional groups, so that the desalination rate and the water permeation flux of the reverse osmosis membrane are both improved, and the reverse osmosis membrane can be applied to the fields of purified water preparation, industrial sewage and wastewater deep treatment, seawater desalination and the like.

The invention provides a composite heat storage material and a preparation method thereof, and relates to the technical field of phase change heat storage materials. The composite heat storage material comprises the following raw materials in percentage by mole: 10-70% of sodium hydroxide, 1-5% of potassium hydroxide, 10-60% of sodium nitrate and 10-70% of sodium nitrite. The prepared composite heat storage material has the characteristics of stable thermal cycle performance, high phase change heat storage density and the like, and is suitable for the field of medium-temperature heat storage.

The invention discloses a phototherapy reagent and a preparation method and application thereof. The preparation method comprises the following steps: 1-[4-(diethylamino) phenyl]-ethane-1-ketone and 4-methoxybenzaldehyde are subjected to a condensation reaction in a NaOH ethanol solution, and a product and nitromethane are subjected to addition; performing condensation and addition on the other groups of raw materials by the same method; cyclizing the two addition products with ammonium acetate, and coordinating with boron trifluoride diethyl etherate to obtain NHM; carrying out substitution reaction on the NHM and sodium nitrite to obtain NOO; and oxidizing NOO by m-chloroperoxybenzoic acid to obtain NNOO. The reagent can target a tumor hypoxia microenvironment, hypoxia monitoring is achieved, NO is released through photostimulation for tumor gas therapy, meanwhile, the secondary amplification photo-thermal therapy effect is achieved, preparation is controllable, diagnosis and treatment are integrated, and the reagent is sensitive, safe and suitable for biomedical research and clinical diagnosis.

The present invention relates to a method for preparing a high-purity peramivir intermediate. The method comprises the following steps: Step 1: adding compound II to a reaction kettle, and dropwise adding a sodium borohydride methanol solution; after the dropwise addition is completed, the reaction is stirred at a controlled temperature; purified water and a sodium nitrite solution are added, and the reaction is stirred to prepare compound (III); Step 2: adding acetic anhydride dropwise to compound (III), and the reaction is stirred at a controlled temperature; Step 3: adding a sodium carbonate aqueous solution, stirring, separating the liquids, collecting the organic phase, concentrating under reduced pressure, adding a solvent, stirring and crystallizing, and centrifuging until no obvious liquid flows out; vacuum drying the filter cake to obtain an off-white crude peramivir acetylate (IV); Step 4: refining to obtain an off-white solid peramivir acetylate (IV). #imgabs0#

The present application relates to a kind of five-ring thiazole indole ketone piperazine amide derivatives and purposes thereof.The derivatives take ethyl cyanoacetate as starting material, generate hydroxylamine compound (A) under the action of sodium nitrite and phosphoric acid;Obtain 2-amino ethyl cyanoacetate (B) by reduction, in turn with acetic anhydride, lawson reagent is reacted, and 5-amino-4-carboxylate thiazole compound (D) is obtained;After bromination by NBS, under the catalysis of phosphorus oxychloride, react with tetrahydropyridine indole ketone, generate 2-bromo-6,7-dihydrothiazolo [5'',4'':4',5'] pyrimido [1',2':1,2] pyrindo [3,4-b] indole-4 (12H) -ketone (F), again under alkaline condition, first with Boc piperazine, then by Boc treatment and obtain compound (H);Finally, react with acyl chloride, and 28 different substitution structures of five-ring thiazole indole ketone piperazine amide compound (I1-I28) are synthesized.The 28 compounds are tested on three kinds of cancer cells, and the results show that: 28 compounds have significant inhibitory activity on Hela cervical cancer cells, HT-29 human colon cancer cells and HGC-27 human gastric cancer cells.

The invention relates to the technical field of organic synthesis, and discloses a synthesis method of 2-fluoro-3-bromine-5-chloroaniline, which specifically comprises the following steps: S1, mixing a compound I, hydrochloric acid and cuprous chloride, dropwise adding a sodium nitrite aqueous solution under the stirring condition of 45-55 DEG C, adding water after the reaction is finished, heating for water steaming, and recrystallizing and purifying with ethanol to obtain a compound II; s2, mixing the compound II with sulfuric acid, dropwise adding dibromohydantoin under a stirring condition at 25-30 DEG C, adding water after the reaction is finished, extracting with ethyl acetate, washing with water, layering, desolventizing, and recrystallizing and purifying with ethanol to obtain a compound III; and S3, mixing the compound III, ethanol and a platinum-carbon catalyst, introducing hydrogen while stirring at 70-80 DEG C, filtering after the reaction is finished, desolventizing filtrate to recover ethanol, cooling to separate out a solid, and filtering to obtain a compound IV, namely 2-fluoro-3-bromo-5-chloroaniline. The method is reasonable in design route, short in synthesis route, high in safety coefficient and suitable for industrial production.

The invention discloses a rapid conversion method for continuous production of diazonium salt, which comprises the following steps: dissolving an amide raw material in a polar solvent, adding acid to obtain an amide salt solution, and dissolving sodium nitrite in water to obtain a sodium nitrite aqueous solution; constructing a reaction system in the reaction kettle; synchronously dropwise adding the amide salt solution and the sodium nitrite aqueous solution into a reaction system according to a set proportion; enabling the amide salt solution and the sodium nitrite aqueous solution to be subjected to a conversion reaction in the reaction kettle through automatic control while dropwise adding in a certain proportion synchronously, so as to generate diazonium salt; after diazonium salt is generated in the reaction kettle, carrying out instant conversion reaction on the diazonium salt and a reaction system to obtain a rapid conversion reaction mixture; and treating the rapid conversion reaction mixture, and separating to obtain a target product. According to the invention, the safety problem of diazonium salt production, storage, transportation and use is solved, the yield of diazotization and next reaction is greatly improved, the automation degree is high, and the purpose of eliminating the danger of diazonium salt can be achieved.

The invention relates to a method for preparing a 4-chloro-3-nitroanisole compound, in particular to a method for preparing a 4-chloro-3-nitroanisole compound by using a microreactor, which comprises the following steps: carrying out a raw material diazotization reaction by using the microreactor, then carrying out a chlorination reaction in an intermittent tank reactor, and taking 2-methoxy-4-nitroaniline as a raw material to prepare the 4-chloro-3-nitroanisole compound. The 4-chloro-3-nitroanisole compound is prepared from sodium nitrite and cuprous chloride. According to the invention, diazotization of 4-chloro-3-nitroanisole is realized on the micro-reaction device, and the method has the advantages of simple process, continuous production, small reaction volume, short reaction time, small corrosion to equipment, high operation safety and the like. Meanwhile, by utilizing the characteristics of high-efficiency heat mass transfer capacity and easiness in direct amplification of the microchannel reactor, the yield is high and is 80-85%, the product quality is good, the energy consumption is low, and the method is a green, environment-friendly and high-efficiency method for preparing the 4-chloro-3-nitroanisole and is suitable for industrial application.

The invention relates to the technical field of food processing, and discloses a tuna sausage which comprises the following components in parts by weight. The tuna sausage is prepared from, by weight, 40-50 parts of cooked tuna, 15-18 parts of chicken breast, 19-23 parts of chicken thigh, 0.8-1.0 part of edible salt, 0.001-0.003 part of sodium nitrite, 0.3-0.4 part of composite phosphate, 2.5-2.7 parts of erythritol and 8-10 parts of ice water, the prepared tuna sausage is pure in flavor, the flavor is mildly removed through precise matching, and the original delicate flavor of tuna is perfectly reserved. The taste is dominated by meat feeling, and the texture is elastic and juicy and is free of powder texture and dry firewood feeling. The formula is simple, chemical additives are greatly reduced, and the product conforms to the trend of cleaning labels and is a high-quality product with natural flavor, excellent taste and health attribute.

The present application provides a composition and a fracturing fluid containing the same. The composition provided by the present application comprises ammonium chloride, sodium nitrite and a flow enhancer. The flow enhancer is a chemical loading product of a compound shown in a structural diagram as Formula I on nano-silicon dioxide; wherein A is an optionally substituted naphthalene ring; n is an integer from 1 to 10; n R is independently selected from one of a chemical single bond and a C1 to C 10 alkylene group; and n X is independently selected from -O- or -NH-, and at least one X is -NH-. The fracturing fluid comprises the composition, a thickening agent, a clay stabilizer, a cleanup agent, a crosslinking agent, a pH regulator and water.

Disclosed in the present invention are a method for synthesizing deucravacitinib and intermediates thereof. An intermediate 2-methoxy-3-(1-methyl-1H-1,2,4-triazol-3-yl)aniline is prepared by subjecting 2,3-dichloronitrobenzene to an etherification reaction and a cyanation reaction to prepare 2-methoxy-3-nitrobenzonitrile; then reacting 2-methoxy-3-nitrobenzonitrile with ammonium chloride under the action of an alkali to generate 3-(2-methoxy-3-nitrophenyl)-1-methyl-1H-1,2,4-triazole; and finally, carrying out a catalytic reduction reaction to obtain the target product. Another intermediate N-(5-bromo-6-cyanopyrazin-3-yl)cyclopropanecarboxamide is prepared by subjecting 3-amino-6-chloropyridazine to a bromination reaction to prepare 3-amino-4-bromo-6-chloropyridazine, then reacting 3-amino-4-bromo-6-chloropyridazine with sodium nitrite under low-temperature condition and in the presence of an acid to generate a diazonium salt, and then adding a cyanate reagent to generate 4-bromo-6-chloro-3-cyanopyridazine; and finally carrying out a substitution reaction to obtain a target product (I). Deucravacitinib is obtained by subjecting these intermediates to a Buchwald-Hartwig coupling reaction, carrying out nitrile hydrolysis, and carrying out condensation.

The invention discloses a tetrazine probe synthon and a preparation method and application thereof.The preparation method comprises the following steps that under the inert atmosphere, diethyl cyanomethylphosphonate, 3-hydroxypropionitrile, 3-mercaptopropionic acid and hydrazine hydrate are mixed and then react at the room temperature, a sodium nitrite solution is added after the reaction is finished, then acid is continuously added till the reaction system reaches acidity, and a tetrazine probe synthon product is obtained; continuously reacting to obtain an intermediate; and dissolving the intermediate in a solvent in an inert atmosphere, adding triethylamine, slowly adding methanesulfonyl chloride, and reacting at room temperature to obtain the tetrazine probe synthon shown in the formula I. The invention further discloses a preparation method of the tetrazine probe synthon. The tetrazine probe synthon provided by the invention can perform series Heck reaction and HWE reaction, so that controllable combination of functional groups on two sides of a tetrazine coupling probe is realized under mild reaction conditions, and the functional groups on two sides are designed according to actual requirements to regulate and control photophysical properties of the probe. A brand new way is provided for developing a high-performance biological orthogonal fluorescent probe.

This application relates to a highly acid and alkali resistant pigment, Red 48:1, and its preparation process, belonging to the field of chemical pigment manufacturing technology. The pigment is prepared from 2B acid, sodium nitrite, 2,3 acid, a barium-lanthanum-calcium multimetallic salt component, aminotrimethylenephosphonic acid, zirconium salt, melamine-formaldehyde resin prepolymer, epoxy resin emulsion, silane coupling agent, and surfactant. The preparation process includes sequential diazotization and coupling reactions, followed by a co-lake reaction with the addition of multimetallic salts; then interfacial anchoring via aminotrimethylenephosphonic acid, and inorganic deposition hybridization via droplet addition of zirconium salt; finally, a staged crosslinking coating reaction is performed with the aforementioned resin and coupling agent. This invention constructs an inorganic-organic hybrid coating layer in situ on the pigment core surface of the multimetallic lake, physically blocking the penetration pathways of acid and alkali ions, thus improving the pigment's resistance to acid and alkali bleeding and its resistance to ultraviolet aging.

This invention provides a high-hygroscopic, water-free composite gel-type calcium and magnesium salt tablet and its preparation method, which is made from the following raw materials in parts by weight: 45-70 parts calcium and magnesium salt, 15-25 parts gum arabic, 3-15 parts mica powder, 2-12 parts polyethylene oxide, 0.5-2 parts sodium nitrite, and 2-30 parts gelatin. This tablet exhibits high hygroscopicity and excellent physical properties.

The present application provides a kind of nitromethane tail gas treatment method, comprising the following steps: sodium hydroxide or potassium hydroxide aqueous solution and low-grade fatty diol and organic base miscible to form mixed solution after preheating, then nitromethane tail gas is passed into mixed solution and reacts, reaction end product is separated and purified to obtain corresponding sodium nitrite or potassium nitrite product.The present application also provides a kind of nitromethane production method, including the sodium nitrite or hydrogen potassium obtained above as raw material to recycle production nitromethane.The method of the present application solves the problem of nitromethane tail gas treatment, also can turn waste into treasure, reduce production cost, conducive to nitromethane production and environmental protection.

The application discloses a high-strength steel unqualified zinc-cadmium alloy plating layer stripping method, and its stripping process is as follows: 80-150 g / L of sodium nitrite, 50-100 g / L of ammonium bicarbonate, 50-100 g / L of ammonium chloride, the pH of the stripping solution is 6-8, and normal temperature operation is adopted. The sodium nitrite is used as an oxidizing agent and a steel base inhibitor for the zinc-cadmium alloy plating layer, the ammonium bicarbonate is used as a complexing agent for zinc ions and cadmium ions and a pH buffer for the plating solution, and the ammonium chloride is used as a complexing agent for zinc ions and cadmium ions and a promoter for dissolving the zinc-cadmium alloy plating layer. When the pH of the stripping solution is too high, dilute nitric acid is used to reduce the pH, and when the pH is too low, sodium carbonate solution is used to increase the pH. The technical scheme of the application is used to replace the chromium acid stripping method, and the high pollution problem caused by the use of the chromium acid is overcome.

The present invention introduces an innovative approach to safeguard the integrity and cleanliness of gravity chutes, particularly those featuring polished stainless steel inner linings. The invention leverages the exceptional rust preventative properties of Sodium Nitrite, a water-soluble compound, to protect the inner surfaces of gravity chutes from corrosion and rust formation. This method involves the systematic application of a Sodium Nitrite concentrated solution into the waterline, precisely below the main water valve, following the completion of the chute's wash cycle. This process, conducted on a periodic basis based on gravity chute conditions, creates a protective barrier on the polished stainless steel inner lining, effectively preventing rust formation.

This invention belongs to the field of pharmaceutical technology, specifically relating to the application of a traditional Chinese medicine composition in the preparation of drugs for improving cognitive impairment. By weight, the traditional Chinese medicine composition comprises: 225-300 parts rhubarb, 50-75 parts pig bile powder, 90-120 parts aster, 360-480 parts scrophularia, 180-240 parts immature bitter orange peel, and 180-240 parts areca nut. This invention is the first to demonstrate that a composition of six traditional Chinese medicines, including scrophularia, rhubarb, and areca nut, significantly improves memory acquisition (induced by scopolamine), consolidation (induced by sodium nitrite), and retrieval impairments, covering the entire process of memory formation, encoding, storage, and retrieval, thus overcoming the limitations of existing drugs that only target a single memory stage.

The present invention discloses a nanoprobe and portable detection device for detecting propofol in serum, relating to the field of biomedical detection technology. The nanoprobe comprises UCNPs and a diazonium salt, wherein the diazonium salt is formed by the reaction of p-aminobenzenesulfonic acid and sodium nitrite. The nanoprobe uses the diazonium salt as a propofol recognition unit, and the UCNPs as an energy donor. In the presence of propofol, the nanoprobe can cause luminescence quenching. The rapid and specific response between the diazonium salt and propofol enables rapid, sensitive, and visual detection of propofol.