669 results about "Sodium nitrite" patented technology

The invention relates to the technical field of biological sewage treatment, in particular to a device and a method for improving the autotrophic nitrogen removal performance of an MABR (Membrane Ammonia Baffled Reactor). Coupling of partial nitrosation reaction and anaerobic ammonia oxidation reaction is completed; through a circular reaction zone and a membrane reaction zone in the reaction tank, nitrate nitrogen generated by anaerobic ammonia oxidation and excessive nitrite nitrogen during instability regulation are circularly removed, and the purpose of improving the total nitrogen removal effect of the reactor is achieved; a proper amount of a sodium nitrite solution is added at proper time, the concentration of free nitrous acid in a mixed solution of the reactor is increased, and the intermittent proportion of MABR intermittent aeration is synchronously regulated and controlled, so that the activity of nitrite oxidizing bacteria is synergistically inhibited by low dissolved oxygen and high free nitrous acid, and the unstable short-cut nitrification reaction is recovered again; the autotrophic nitrogen removal performance of the reactor is improved.

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 discloses a method for continuously producing fluorobenzene, which comprises the following steps: S10) mixing anhydrous hydrogen fluoride and aniline in a tubular reactor to obtain an aniline hydrofluoride mixture; s20) introducing the aniline hydrofluoride mixture into a venturi tube reactor in an inert gas atmosphere, sucking powdered and dried sodium nitrite into the venturi tube reactor in a negative pressure environment formed by the venturi tube reactor, and carrying out a synthetic reaction to obtain a diazonium solution; s30) transferring the diazonium solution into a tubular reactor for pyrolytic reaction to obtain a crude fluorobenzene solution; s40) refining the crude fluorobenzene raw material to obtain fluorobenzene; according to the method disclosed by the invention, the crossing from an intermittent artificial kettle reaction to a continuous reaction is realized, the reaction is sufficient and complete, no 70% hydrofluoric acid mother liquor, no 70% sulfuric acid waste liquor, no high-concentration wastewater and no yellow mud solid waste are produced, a high-quality fluorobenzene product can be continuously prepared in a large batch, and the method has good economic and environmental benefits and a wide market application prospect.

The invention discloses a corrosion-resistant polypropylene edge band material and a preparation method thereof, and belongs to the technical field of preparation of edge band materials. The corrosion-resistant polypropylene edge sealing strip material is prepared from, by weight, 50-75 parts of polypropylene, 2-5 parts of an antioxidant, 3-6 parts of a corrosion-resistant agent, 2-4 parts of a composite flame retardant, 8-15 parts of calcium carbonate and 2-4 parts of dye, the corrosion-resistant agent is prepared from 2, 6-dichlorobenzonitrile, 1, 2, 4-triazole, a sulfuric acid solution, sodium nitrite and parachloroaniline, and the corrosion-resistant agent is prepared from 2, 6-dichlorobenzonitrile, 1, 2, 4-triazole, a sulfuric acid solution, sodium nitrite and parachloroaniline. The composite flame retardant is prepared from 3-glycidyl ether oxypropyl trimethoxy silane, diphenyl silanediol, barium hydroxide and boric acid. The edge band material prepared by the method has excellent corrosion resistance, flame retardance, heat resistance and mechanical properties.

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 discloses a comprehensive dealkalization method for vanadium extraction waste slag, which comprises the following steps: mixing the vanadium extraction waste slag with a calcium additive, a carbonaceous reducing agent and sodium nitrite for pelletizing, decomposing a sodium-containing solid solution in the vanadium extraction waste slag by adopting a roasting process, and leaching a sodium-containing phase in the waste slag by adopting a hydrothermal leaching process, thereby achieving the purpose of dealkalization. And drying the leaching residues to obtain a sodium-removed iron-containing material, recycling the sodium-removed iron-containing material for an iron-making process, and performing multi-effect evaporation on the leaching solution to form a sodium-containing product which can be directly sold. The process equipment is simple, operation is easy and convenient, recycling of the vanadium extraction waste slag in iron and steel enterprises can be achieved, meanwhile, the process is high in energy utilization rate, little in environmental pollution and low in operation and maintenance cost, large-scale recycling of the vanadium extraction waste slag can be achieved, and good economic benefits and social benefits are achieved.

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 the technical field of contact lens care and catalysis, in particular to a platinum alloy neutralization ring for a hydrogen peroxide care solution and a preparation method of the platinum alloy neutralization ring. The problems that in the prior art, a platinum alloy is poor in neutralization ring cycle catalytic performance and insufficient in antibacterial and bactericidal performance are solved. The preparation method comprises the following steps: adding an organic solvent and a silver nitrate solution to carry out swelling treatment, surface silver ion plating and reduction on a plastic substrate to obtain a silver-plated substrate, complexing a metal complexing agent and platinum salt, and activating by sodium nitrite to form a platinum nano layer on the surface of the silver-plated substrate to obtain a platinum alloy neutralization ring; the type of the metal complexing agent is adjusted to improve the stability of the plating solution A; the chemical plating temperature and time are controlled, and the catalytic rate of a neutralization ring is increased; the dosage composition ratio of the metal complexing agent is controlled, and the catalytic ability of the neutralizing ring is improved; the cyclic catalytic performance of the neutralization ring is improved by changing the dosage of the organic solvent; the use amount of each component of the organic solvent and the use amount of silver nitrate are adjusted, so that the antibacterial property of the platinum neutralizing ring is improved.

The invention relates to the technical field of polyurethane coatings, and discloses a preparation method of an antibacterial wear-resistant waterborne polyurethane coating, which comprises the following steps: taking concentrated hydrochloric acid, p-phenylenediamine, sodium nitrite, paraformaldehyde, amino-modified nano silicon dioxide and hexamethylene diisocyanate as raw materials; the preparation method comprises the following steps: taking 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a raw material, carrying out diazotization coupling reaction, substitution reaction, Mannich reaction and addition reaction to prepare modified polyisocyanate, then taking 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and ((2-aminoethyl) azadiyl) dimethanol as raw materials, carrying out substitution reaction to prepare DOPO-based dihydric alcohol, and carrying out reaction to prepare the DOPO-based dihydric alcohol. Finally, the modified polyisocyanate, DOPO-based dihydric alcohol and polyethylene glycol 400 are used as raw materials, an antibacterial wear-resistant polyurethane emulsion is prepared through a prepolymerization reaction and a chain extension reaction, and the prepared polyurethane coating has good antibacterial, anti-ultraviolet, flame-retardant and wear-resistant properties.

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 discloses a preparation method of a thidiazuron preparation, and relates to the technical field of thidiazuron preparation. The preparation method of the thidiazuron preparation comprises the following steps: adding 5-amino-1, 2, 3-thiadiazole, ethylene glycol dimethyl ether and triethylamine into a four-neck flask, heating and uniformly stirring, dropwise adding phenyl isocyanate into the mixed solution obtained in the step 1, heating to carry out catalytic synthesis reaction, cooling to room temperature, and carrying out suction filtration to obtain yellow solid thidiazuron. And further treating to obtain the thidiazuron preparation. Sodium nitrite is selected as a solvent in the preparation process of 5-amino-1, 2, 3-thiadiazole, and the amount of substance of another initial material aminoacetonitrile hydrochloride is controlled in the preparation reaction, so that the yield of thidiazuron is ensured to be optimal, the reaction temperature range and the dropwise adding amount are determined, the optimal reaction conditions are finally perfected, and the yield of 5-amino-1, 2, 3-thiadiazole is improved. A preparation mode which is simpler to operate, higher in yield and suitable for industrial production is provided for preparation of the thidiazuron preparation.

The invention discloses a brassica rapa alkali extract with anti-hypoxia activity as well as a preparation method and application of the brassica rapa alkali extract. The method comprises the following steps: by taking brassica rapa tuberous roots as a raw material, rinsing, slicing, drying, crushing, extracting with a food-grade calcium oxide alkaline solution, carrying out centrifugal separation to obtain supernate, and carrying out spray drying on the supernate to obtain the brassica rapa alkali extract. The method is easy to operate, low in cost and high in extraction rate, starch and crude fiber auxiliary components in the brassica rapa tubers can be removed to a large extent, the most important components with health-care functions of brassica rapa are reserved, and the biological activity of nutritional components of brassica rapa is kept. Results of evaluation and biochemical index determination of a normal-pressure closed experiment and a sodium nitrite poisoning experiment show that the brassica rapa alkali extract can remarkably prolong the survival time of mice, improve the activity of superoxide dismutase in the mice and reduce the content of malondialdehyde, and shows a relatively good hypoxia tolerance effect. The alkali extract can be used for developing hypoxia-resistant functional foods such as tabletted candies and biscuits, and has a wide application prospect.

The invention provides a preparation device and method of 2, 2-dinitropropanol, and the preparation device provides 2-nitropropanol, a sodium nitrite aqueous solution, a sodium persulfate aqueous solution and a solvent for an oxidation nitration unit through a raw material unit, and provides a potassium ferricyanide aqueous solution for the oxidation nitration unit through a catalyst unit. The oxidation and nitration unit is selected from at least one of a microchannel reactor and a tubular reactor, so that the oxidation and nitration reaction is carried out in the microchannel reactor and the tubular reactor, and the production efficiency and the product yield of synthesizing and preparing the 2, 2-dinitropropanol can be improved.

The invention relates to the field of medicine synthesis and preparation, in particular to a synthesis method of toxyanib phosphate. The use amount of acetic acid is greatly reduced in the preparation process, so that excessive acid does not need to be neutralized in the post-treatment process, and a large amount of wastewater is not generated; in addition, the use amount of sodium nitrite is reduced, and the environment and health are facilitated; the enamine reduction reaction does not use acetic acid as a solvent and a hydrogenation reaction catalyzed by heavy metal palladium, so that the safety of the reaction is improved, and the purity of the product is also improved; a decarboxylation reaction and a Vilsmeier-Haack reaction are carried out by a one-pot method, so that the reaction steps are reduced, and the product purity is improved; when aldol reaction is carried out in side chain splicing, side reaction and generation of isomer impurities are reduced. The method is short in route, mild in reaction condition, low in equipment requirement and convenient to operate, industrial production is easy to achieve, and a complex purification method is not needed.

The invention belongs to the technical field of wastewater treatment, and particularly relates to a treatment method of high-concentration ammonia-nitrogen wastewater. The treatment method comprises the following treatment steps: (1) pretreatment of high-ammonia-nitrogen wastewater: adding an acidic solution into to-be-treated high-ammonia-nitrogen wastewater, adjusting the pH value of the system to 3 or below, then adding a regulating agent NaNO2, and uniformly mixing; and (2) high-temperature hydrothermal treatment: putting the mixed wastewater pretreated in the step (1) into a closed hydrothermal reactor, heating to 120-180 DEG C, carrying out high-temperature hydrothermal reaction, cooling after the reaction is completed, obtaining treated produced water, and collecting produced nitrogen. According to the treatment method, the hydrothermal reaction is regulated and controlled based on cooperation of acid and sodium nitrite, the method is carried out under high-temperature and high-pressure conditions, the reaction rate can be increased, the treatment time can be shortened, and the treatment efficiency can be improved. The problems that in an existing high-ammonia-nitrogen wastewater treatment technology, the ammonia nitrogen treatment concentration is low, the process technology is complex, and secondary pollution is generated are solved.

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 belongs to the technical field of fire-extinguishing building materials, and particularly relates to a fire-extinguishing microcapsule and a preparation method thereof and a building material.The preparation method of the fire-extinguishing microcapsule comprises the following steps that 1, a monoethylenic bond compound, a polyethylenic bond compound, a fire extinguishing agent, an oxidizing agent and a stabilizer are mixed in sequence, and an oil phase A is obtained; adding a dispersing agent and salt into deionized water, heating, stirring, cooling, adding sodium nitrite, and uniformly stirring to obtain a water phase B; 2, adding the oil phase A into the water phase B, and stirring to obtain white dispersion liquid C; adding a reducing agent, an accelerant and a polyethylenic bond compound into the water phase B in which the emulsifier is dissolved, and stirring to obtain a white emulsion D; and step 3, dropwise adding the emulsion D into the dispersion liquid C, and removing a water phase to obtain the fire extinguishing microcapsule M. The preparation method has the beneficial effects that the obtained fire extinguishing microcapsule can be softened and broken at a certain temperature, a vaporized fire extinguishing agent is released, and active fire extinguishing is achieved in the early stage of a fire; safety and environmental protection.

The invention discloses phosphate-free emulsified minced pork and a preparation method thereof. The phosphate-free emulsified minced pork is prepared from the following raw materials in parts by weight: 50 to 60 parts of tenderloin, 5 to 15 parts of pig backfat, 0.5 to 1.5 parts of sodium chloride, 5 to 10 parts of degreased peanut powder, 0.02 to 0.06 part of D-sodium erythorbate, 0.01 to 0.012 part of sodium nitrite and 22 to 28 parts of deionized water. Sodium tripolyphosphate in emulsified minced pork can be completely replaced by the degreased peanut powder, and the purpose of reducing phosphate instead of reducing the quality of the emulsified minced pork is achieved. The degreased peanut powder used in the invention contains a large amount of high-quality peanut protein and dietary fiber, also has the strong fragrance of peanuts, and is a high-quality food ingredient.

The invention relates to the technical field of ultraviolet absorbents, in particular to a synthesis method of a hexafluoropropylene oxide tripolymer, which comprises the following steps: S1, carrying out reaction on cyanuric chloride and aromatic hydrocarbon to obtain an intermediate product 1-chloro-3, 5-diaryltriazine, S2, carrying out reaction on cardanol and nitric acid to generate an intermediate product nitro cardanol, S3, carrying out reaction on 1-chloro-3, 5-diaryltriazine and 1-chloro-3, 5-diaryltriazine, and carrying out reaction on 1-chloro-3, 5-diaryltriazine and 1-chloro-3, 5-diaryltriazine to obtain the hexafluoropropylene oxide tripolymer. The preparation method comprises the following steps: (1) reacting 2, 5-diaryltriazine with nitrocardanol to obtain an intermediate product A, (2) reacting the intermediate product A with active iron powder and diluted hydrochloric acid to obtain an intermediate product B, and (3) continuously stirring the intermediate product B with sodium nitrite, nitrous acid and diluted hydrochloric acid to react, and adding a reducing agent and heating after the reaction is finished to obtain the target product cardanol modified triazine ultraviolet absorbent. The synthesis method of the triazine ultraviolet absorbent provided by the invention has the advantages of simple reaction conditions, green production and high weather resistance of the product.

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 a colloidal emulsion explosive with high storage stability and a preparation method thereof. The raw materials for preparing the emulsion explosive comprise ammonium nitrate, calcium nitrate, water, a compound emulsifier, compound wax and a special foaming agent. Wherein the composite emulsifier is a modified span-80 composite emulsifier obtained by carrying out esterification reaction on an anionic carboxylate emulsifier and multiple hydroxyl sites of span-80, and the composite emulsifier has high molecular weight, so that the space volume of a lipophilic group is increased, and an interfacial film is tighter; the special foaming agent is composed of sodium nitrite, zinc nitrate, gelatin peptone, Tween 80, phosphoric acid, urea and water, the gelatin peptone is a green pure natural raw material, the surface tension of an emulsion matrix is effectively reduced, the contact area of the foaming agent and the emulsion matrix is increased, the foaming efficiency is catalyzed by zinc nitrate, and bubbles are good in stability and not prone to escaping due to Tween 80. The use of the compound emulsifier and the special foaming agent improves the blasting performance and storage stability of the emulsion explosive.

The present invention discloses a high-purity photochlorination synthesis method of p-fluorobenzoyl chloride, wherein an aromatic nitro compound or its salt is selected to form an inhibition system with triethanolamine, which not only inhibits side reactions, but also inhibits the photochlorination process to inhibit fluorotoluene, the self-luminous defluorination of p-fluorotrichlorobenzyl, and the high-temperature defluorination of p-fluorobenzoyl chloride in the distillation process, thereby further improving the purity of the synthesized p-fluorobenzoyl chloride to above 99.5. The aromatic nitro compound or its salt is specifically any one or two of nitrobenzene, dinitrobenzene, nitrotoluene, sodium nitrite or potassium nitrite, preferably potassium nitrite; the dosage is 0.1‰ to 1‰ of the mass of p-fluorotoluene, and the addition amount and time are strictly controlled to ensure that the effect of inhibiting the defluorination is achieved while ensuring the safety of the reaction process and the product, and has good practical value and important economic value.

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 belongs to the field of organic synthesis, and particularly relates to an efficient method for preparing ethyl chrysanthemate by using a Beta / CuCl nano molecular sieve catalyst. Glycine ethyl ester hydrochloride and sodium nitrite react in a heptane solvent to generate ethyl diazoacetate, and then ethyl diazoacetate reacts with octa-carbene to generate ethyl chrysanthemumate. The catalyst provides an acidic environment and active sites, promotes generation of diazo compounds, controls reactant diffusion through a pore channel structure, and improves the reaction rate and selectivity. The catalyst stabilizes the carbene intermediate and reduces the reaction temperature. The catalyst can be recycled, and environmental pollution and cost are reduced. The yield of the ethyl chrysanthemate exceeds 98%, the yield and quality are improved, and a new scheme is provided for the sanitary insecticide and pharmaceutical industry.

Described herein is a combination of a catalyst and an activator and method of use for causing an exothermic reaction in a low temperature environment. The mixture can include sodium nitrite, an ammonium-based compound, a catalyst that comprises an oxidizer, and an activator and can be injected into a fluid flow path. The fluid flow path can be a pipeline, a flowline, a wellbore, or a subterranean formation. The mixture can cause an exothermic reaction in the fluid flow path and remove, using the exothermic reaction, a damaging material from the fluid flow path.

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 discloses a synthesis method of 5-nitrotetrazole sodium salt, and solves the problem of relatively large potential safety hazard in the synthesis process of 5-nitrotetrazole sodium in the prior art. The method for safely preparing the high-energy compound 5-nitrotetrazole sodium salt based on DAT comprises the following steps: adding 1, 5-diamino tetrazole into a certain amount of ice water and acid to dissolve 1, 5-diamino tetrazole; slowly dropwise adding a sodium nitrite solution into the ice-water mixture solution, and uniformly stirring at a certain temperature; slowly heating the mixture to a certain temperature, and reacting for a period of time to obtain filtrate; removing filtrate to obtain white powder; and dissolving the obtained white powder in acetone, filtering to obtain a solution, and removing the solvent to obtain the 5-nitrotetrazole sodium salt. The preparation method provided by the invention is simple, safe and mild in reaction condition; water is used as a solvent, so that environmental pollution is avoided, and environmental protection requirements are completely met; and dangerous intermediates such as tetrazole-5 diazonium salt and 5nitrotetrazole acid copper salt are not generated.

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.