144 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 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 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 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 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 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 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.

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 invention relates to the technical field of organic synthesis, in particular to a green synthesis method of a benzotriazole compound. A conventional o-phenylenediamine method for synthesizing benzotriazole compounds needs to accumulate under the action of sodium nitrite and acid to generate a large number of diazonium salt intermediates with high explosion risk, and the diazonium salt intermediates are separated and then subjected to cyclization reaction. In order to solve the problems, the invention provides the green synthesis method of the benzotriazole compound, o-phenylenediamine, a derivative of o-phenylenediamine and nitrate are used as initial raw materials, and the benzotriazole compound is generated by heating reaction in an organic solvent under the action of a reducing agent. And the stability and color of the product are effectively guaranteed. Meanwhile, a sodium nitrite system is avoided, the toxicity in the reaction process is reduced, the accumulation of diazonium salt is avoided, the explosion risk is reduced, and the reaction safety is improved.

The invention belongs to the technical field of organic synthesis, and discloses ketoxime ether as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing a ketoxime compound, tert-butyl alcohol and alkali to obtain a mixed solution; and adding a methylation reagent into the mixed solution, and reacting to obtain ketoxime ether. The preparation method is low in raw material cost and simple in process operation; tert-butyl alcohol is used as a solvent, sodium tert-butoxide is used as an alkali source, no water participates in the reaction process, ketoxime hydrolysis is effectively reduced, side reactions are greatly reduced, the yield of the obtained product is high, and subsequent separation and solvent recycling are facilitated; use of toxic substances such as sulfur dioxide and sodium nitrite is avoided, and emission of toxic gases such as nitrogen oxides is reduced; and the process safety risk is reduced, and the method is safe, reliable, simple and feasible.

The invention discloses a non-planar pi-conjugated naphthoquinone derivative with an asymmetric structure, a preparation method of the non-planar pi-conjugated naphthoquinone derivative and application of the non-planar pi-conjugated naphthoquinone derivative in an aqueous flow battery, and relates to the technical field of electrochemical energy storage. Methyl 4-aminobenzoate is added into hydrochloric acid, then the mixture and sodium nitrite are dissolved in water to be mixed to obtain a diazonium salt solution, and 2-hydroxy-1, 2, 4-triazole is added into the diazonium salt solution to be mixed to obtain a diazonium salt solution; 2, 4-naphthoquinone is dissolved in a KOH solution and mixed with a diazonium salt solution, after hydrochloric acid acidification, acetic acid recrystallization purification is conducted, and BANQ is obtained; the capacity fading rate of the modified naphthoquinone derivative BANQ is as low as 0.00018% per circle, the modified naphthoquinone derivative BANQ shows excellent cycling stability and redox reversibility, the BANQ molecule has an asymmetric non-planar pi conjugation characteristic, and the sensitivity of a redox core to nucleophilic / electrophilic attack is greatly reduced, so that the cycling stability is improved, and the service life is prolonged. And a new direction and possibility are provided for constructing green sustainable large-scale organic redox active molecules for energy storage through artificial modification of natural products.

This invention provides a method for preparing sodium nitrite, belonging to the field of chemical technology. The method includes the following steps: S1, guiding the slurry from the bottom of the thickener of a crystallizer to a primary vertical centrifuge for centrifugation and dehydration, obtaining sodium nitrite solid crystals and sodium nitrite crystallization mother liquor; S2, introducing the sodium nitrite solid crystals into a washing tank, adding soft water and saturated sodium nitrite reflux liquid, and mixing thoroughly under the action of a stirrer; the washed sodium nitrite solid crystals are then transferred to a secondary vertical centrifuge for centrifugation and dehydration, yielding high-quality sodium nitrite and sodium nitrite filtrate. Most of the saturated sodium nitrite overflowing from the secondary centrifuge returns to the washing tank to adjust the solid content entering the secondary vertical centrifuge; a small portion of the overflow overflows to a filtrate tank equipped with a stirrer, and the filtrate is pumped into the original mother liquor pipeline via a discharge pump. This invention's method for preparing sodium nitrite yields high-quality sodium nitrite with a high yield.

The present application relates to a kind of preparation method and application of metal phthalocyanine-graphite phase carbon nitride / graphene ternary composite material, it solves the problem of poor dispersibility, easy aggregation and poor conductivity of metal phthalocyanine material as electrocatalyst.Existing Preparation method steps include: metal phthalocyanine, graphite phase carbon nitride are added to sulfuric acid, after heating stirring, solution A is prepared by cooling;Solution B is prepared by stirring after adding sodium nitrite to solution A under ice bath;Graphene oxide is ultrasonically dispersed in distilled water to prepare solution C;Solution B is added dropwise to solution C and stirred, then ascorbic acid is added and stirred, the product is centrifuged, washed and dried to prepare metal phthalocyanine-graphite phase carbon nitride / graphene ternary composite material.The ternary composite material prepared by the method is a two-dimensional sheet structure, has high dispersibility, large specific surface area, good conductivity and structural stability;The product of the present application can be used for electrocatalytic reduction of carbon dioxide.

This invention relates to the field of food processing technology, and discloses a method for preparing crispy beef, comprising the following steps: S1, taking 100 parts by weight of beef, adding 3.25 parts by weight of salt, 0.2 parts by weight of peppercorns, 0.4 parts by weight of white wine, 40 parts by weight of ice water, and 0.007 parts by weight of sodium sorbate and 0.015 parts by weight of sodium nitrite dissolved in the ice water, and placing it in a tumbler and stirring for 30 minutes. This invention, through precise marinating, ice water tumbling, and 72-hour low-temperature marinating, allows the marinade to fully penetrate the beef fibers, thoroughly removing the fishy smell, improving water retention, and addressing the problem of dryness. A compound brine using 28 kinds of spices is used, resulting in a rich and layered aroma, overcoming the single flavor deficiency of traditional processes. Frying at 260℃ for 2 minutes creates a crispy exterior and tender interior with a stable texture, and the sugar flavor is diluted to enhance palatability. Combined with aseptic cooling, vacuum packaging, and 121℃ high-temperature sterilization, the shelf life is extended, batches are stable, suitable for industrial production, and significantly improves product quality and competitiveness.

The application relates to the technical field of plugging removing agents for oilfield recovery, in particular to a foamed acid plugging removing system and a preparation method thereof. The foamed acid plugging removing system comprises a foamed acid component, a foaming agent and a gas phase component, and the foamed acid component comprises, in mass ratio, oxalic acid, phosphoric acid, triethanolamine, dimethyl diallyl ammonium chloride, acetic acid, disodium phosphate and sodium nitrite in a mass ratio of (10-12):(3-5):4:2:(1.5-2.5):0.05:0.05:1. The total weight m1 of the foamed acid component and the total weight m2 of the foaming agent satisfy the relationship m1:m2=100:(1.5-2.5). The volume V1 of the gas phase component and the total volume V2 of the foamed acid component satisfy the relationship V1:V2>=40:1. The foamed acid plugging removing system can improve the plugging removing effect of an acid plugging removing agent in a heterogeneous formation, so that the plugging material dissolution rate is above 65%, the dissolution rate is above 1.20g / (m 2 ·h), the foaming multiple is above 4.0, and the stable foaming time is above 420s.

The invention discloses sliced luncheon meat obtained through synergistic step-by-step fermentation of saccharomyces cerevisiae and lactobacillus plantarum and a preparation method of the sliced luncheon meat. The raw materials of the luncheon meat comprise pig hind leg meat, pig back fat, soybean protein isolate, konjac glucomannan, salt, sugar, monascus red, composite phosphate, sodium nitrite, spice powder and ice water. The preparation method comprises the following steps: taking raw material meat, unfreezing, trimming, mincing, stirring, pickling, fermenting with saccharomyces cerevisiae, vacuum chopping, vacuum rolling, fermenting with lactobacillus plantarum, filling, sterilizing, slicing, packaging and performing secondary sterilization. The saccharomyces cerevisiae CMRC 1S (CGMCC No. 30797) and the lactobacillus plantarum CMRC 1L (CGMCC No. 32440) with the preservation number are adopted for step-by-step fermentation, and the two strains have a synergistic effect through process regulation and control, so that the flavor level of the product is effectively enriched, a unique flavor integrating mellow fragrance, ester fragrance and soft sour is formed, and meanwhile, the texture, slicing property and microbial safety of the product are improved.

The application discloses a preparation method of calcium nartograstim, and belongs to the technical field of biological medicines. By optimizing key steps such as degradation, reduction, ion exchange and oxidation of heparin sodium, and combining with specific anion exchange resin, the yield and purity of the product are significantly improved. The method comprises the following steps: mixing heparin sodium with purified water, degrading by adjusting pH value and adding sodium nitrite; continuing to react with sodium hydroxide and sodium borohydride, and then collecting precipitate through sterilization treatment and ethanol precipitation. Subsequently, the precipitate is reacted with anion exchange resin in purified water, and after washing and precipitation, oxidation reaction is carried out. Finally, calcium nartograstim is obtained through filtration, dehydration and drying. Compared with the prior art, the preparation method has higher yield and purity, the molecular weight distribution is more concentrated, the proportion of effective components is higher, and the proportions of small molecule and large molecule impurities are significantly reduced, so that the quality and curative effect of the product are improved.

The invention discloses a low-corrosion ternary nitric acid molten salt heat storage material and a preparation method and application thereof.The method comprises the steps that sodium nitrate powder, potassium nitrate powder and sodium nitrite powder are weighed according to the ratio of K < + > to Na < + > being 1: 1.0-1: 1.5 and the ratio of NO3 <-> to NO2 <-> being 1: 1-1.5: 1 and mixed to obtain a ternary nitric acid molten salt mixture, a silicate additive is added, the mixture is evenly mixed and dried, and a ternary nitric acid molten salt phase preform is obtained; and after fully melting and stirring, cooling and crushing to obtain the low-corrosion ternary nitric acid molten salt. The prepared low-corrosion ternary nitric acid molten salt is small in corrosion, low in melting point, high in decomposition temperature and good in heat stability, and can be used as a heat storage material for solar thermal power generation and other related heat storage fields.

This invention relates to the field of wastewater biological treatment technology, specifically to a device and method for improving the autotrophic denitrification performance of a MABR reactor. It employs a composite membrane module combining a curtain-type silica gel filament membrane with excellent oxygen permeability with a spatial three-dimensional mesh packing material that facilitates the attachment of anaerobic ammonia-oxidizing bacteria, thereby coupling part of the nitrification reaction with the anaerobic ammonia oxidation reaction. Through the circulating reaction zone and membrane reaction zone within the reactor, nitrate nitrogen generated by anaerobic ammonia oxidation and excess nitrite nitrogen during instability adjustment are circulated and removed, thus improving the total nitrogen removal efficiency of the reactor. By adding appropriate amounts of sodium nitrite solution at appropriate times, the free nitrite concentration in the reactor mixture is increased. Simultaneously, the intermittent aeration ratio of the MABR is controlled to achieve synergistic inhibition of nitrite-oxidizing bacteria activity by low dissolved oxygen and high free nitrite, allowing the unstable short-range nitrification reaction to recover and improving the autotrophic denitrification performance of the reactor.

This invention discloses an aminoindole derivative-based porous polymer, its preparation method, and its application, belonging to the field of dye adsorbent technology. The preparation method is as follows: 2-phenylindole is dissolved in acetic acid, and sodium nitrite aqueous solution is added dropwise. The system is then stirred and reacted at low temperature. After the reaction, the precipitate is collected and dried to obtain product 1. Product 1 is dissolved in ethanol, and NaOH solution is slowly added dropwise while stirring and mixing. Na2S2O4 is added, and the reaction is stirred under heating conditions. After the reaction, the precipitate is collected and dried to obtain product 2. Product 2, 1,2-dichloroethane, and dimethoxymethane are stirred and mixed. A catalyst is added, and the reaction is stirred and reacted under heating conditions. After the reaction, the precipitate is collected, washed, and dried to obtain the final product. The aminoindole derivative-based porous polymer of this application has high specific surface area, high adsorption rate, and high adsorption capacity, effectively solving the problems existing in the prior art.

The application discloses a preparation method of 2-ethyl-2-methyl pentanoic acid, wherein in the process of preparing a key intermediate 2-cyanopentanoate (compound B), compound A is removed by using an alkali extraction method, high-purity compound B is separated by using rectification (a yield of 20% and a purity of 98%), and the operation process is simple. In the preparation method, reagents used are sodium methoxide, sodium hydroxide, sulfuric acid, sodium hydride and sodium nitrite, the reagents are simple, the danger is relatively small, and the experimental operation is relatively safe. In the preparation method, the post-treatment processes of alkylation, hydrolysis, deacidification and cyano hydrolysis do not use a chromatographic column purification process, and a conventional extraction distillation operation is adopted, so that the output of unit volume of instrument equipment is high.

The invention discloses an anti-freezing solution for transportation and storage of solid particles as well as a preparation method and application of the anti-freezing solution, and belongs to the technical field of anti-freezing solutions for railway transportation. The raw materials comprise the following components in parts by weight: 660-1006 parts of calcium chloride; and 1312 to 2000 parts of water. 10 to 15.2 parts of borax; 6 to 9 parts of triethanolamine; 10 to 15 parts of sodium nitrite; and 2-3 parts of hydroxyethyl cellulose. According to the anti-freezing solution disclosed by the invention, the strict requirements of transportation or storage of solid particulate matters under extremely cold conditions on efficient, anti-corrosion, safe and environment-friendly anti-freezing solutions are met by utilizing the synergistic effect of all the components.

The embodiment of the invention discloses aspergillus niger NO1 and application thereof. The Aspergillus niger NO1 disclosed by the invention is preserved in the Guangdong Microbial Culture Collection Center on November 21, 2025, the preservation address is the 5th floor, No.59 building, No.100 Courtyard, Xianlie Middle Road, Guangzhou, and the preservation number is GDMCC No: 67338. According to the invention, the bottom mud and high-enrichment culture sewage of sea farms in Zhangzhou Dragon Sea as well as Zhangzhou Dragon Sea are used as samples, and are subjected to primary screening and secondary screening culture to obtain a strain with excellent growth performance and good utilization performance on sodium nitrite. Through identification, the strain is aspergillus niger NO1, has an efficient aerobic denitrification function, shows excellent degradation efficiency on nitrite in aquaculture water, is good in safety, does not generate adverse effects on aquaculture organisms and water environment, and has a wide practical application prospect in the field of aquaculture water quality purification.

A kind of quaternary mixed molten salt heat transfer and heat storage medium belongs to the field of physical heat transfer energy storage technology in high-tech.The component ratio of high decomposition temperature mixed molten salt heat transfer and heat storage medium is as follows: 30-70wt% potassium nitrate, 20-60wt% sodium nitrate, 5-45wt% sodium nitrite, 0.5-20wt% sodium carbonate.The decomposition temperature of the mixed molten salt is greater than 700℃, the melting point is lower than 150℃, and it has a wide range of use temperature.

The preparation method comprises the following steps: dissolving 1-10 parts by mass of p-aminobenzoic acid in 20-50 parts by mass of deionized water, slowly adding 2-10 parts by mass of concentrated hydrochloric acid (with the mass fraction of 37%), stirring the mixture on a magnetic stirrer for 1-10 hours, then putting the mixture into an ice bath tank, stirring and cooling at the temperature of 0-5 DEG C, and filtering the mixture to obtain the self-color-changing ammonia-removing composite material. A p-aminobenzoic acid mixed solution is obtained; 1-5 parts by mass of sodium nitrite is weighed and dissolved in 20-50 parts by mass of deionized water to prepare a clear solution, the clear solution is poured into a constant-pressure dropping funnel, the sodium nitrite solution is slowly dropwise added into the para aminobenzoic acid mixed solution under stirring, the dropwise adding rate is controlled to be 1-10 drops per second, and after dropwise adding is completed, the composite material is large in purification amount, high in purification efficiency and capable of being distinguished by naked eyes; whether the ammonia concentration exceeds the standard or whether purification is completed or not can be rapidly known, in the self-color-changing ammonia removal process, non-toxicity, harmlessness, safety and environment friendliness are achieved, low-concentration pollution is well removed, and the air quality is guaranteed.