237 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 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 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 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 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 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.

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 present invention provides a polymer-based fracturing fluid and its application. The fracturing fluid provided by the present invention comprises a flowback promoter, a polymer thickener, a clay stabilizer, a drainage aid and water. The flowback promoter comprises ammonium chloride, sodium nitrite and a flow enhancer. The flow enhancer is a chemically loaded product of a compound shown in the structural diagram of Formula I on nano-silica; wherein A is a naphthalene ring at an optional substituted position; n is an integer from 1 to 10; n Rs are independently selected from a chemical single bond and C1 to C 10 One of the alkylene groups; n Xs are independently selected from -O- or -NH-, and at least one X is -NH-.

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 invention relates to a flavoring agent composition. The flavoring agent composition comprises the following components in parts by weight: 5-10 parts of cinnamon; 10-20 parts by weight of anise; 30-50 parts by weight of Chinese prickly ash; 1-5 parts by weight of myristica fragrans; 5-10 parts by weight of bay leaves; 10-20 parts by weight of dried orange peel; 1-5 parts by weight of dahurian angelica root; and 1-5 parts by weight of rhizoma kaempferiae. The invention also relates to a meat product which comprises the following components in parts by weight: 60-120 parts of raw material beef; 0.5-3 parts by weight of the spice bag according to the claim 5; 5-10 parts by weight of edible salt; 0.5-3 parts by weight of white granulated sugar or soft white sugar; 2-10 parts by weight of sweet soybean paste; 2-8 parts by weight of fermented bean curd; 0.5-3 parts by weight of marinated meat paste; 0.5-3 parts by weight of a yeast extract; and 100 to 200 parts by weight of water. The invention also relates to a method for preparing the meat product. On the premise of not adding sodium nitrite and / or phosphate, the color, taste, flavor and the like of the meat product disclosed by the invention are more excellent than those of the meat product added with sodium nitrite and / or phosphate.

The invention discloses a synthesis method of 9, 9-bis (trifluoromethyl)-2, 3, 6, 7-xanthene tetracarboxylic dianhydride, which comprises the following steps: (1) carrying out condensation reaction on N-methyl-4-nitrophthalimide and hexafluoroacetone trihydrate under the catalysis of trifluoromethanesulfonic acid to obtain a first intermediate; (2) performing catalytic etherification reaction on the first intermediate in the presence of sodium nitrite to obtain a second intermediate; (3) carrying out hydrolysis reaction on the second intermediate under an alkaline condition to obtain a third intermediate; and (4) dehydrating the third intermediate into anhydride to obtain 9, 9-bis (trifluoromethyl)-2, 3, 6, 7-xanthene tetracarboxylic dianhydride. According to the method, raw materials are low in price and easy to obtain, the reaction yield and the product purity are high, particularly, the situation that potassium permanganate oxidation or nitric acid oxidation is insufficient in the prior art is avoided, and the method is higher in safety, more environmentally friendly and suitable for large-scale industrial production.

The present invention belongs to the technical field of paper-wrapped flat copper wires. Provided are paper-wrapped flat copper wires and a preparation process therefor. The surface of aramid insulation paper is activated by using plasma method surface modification and combining sodium nitrite and an active oxygen gas, thereby significantly improving the surface energy of the aramid insulation paper, such that the interface bonding force between the aramid insulation paper and a metal conduit is significantly improved, and the prepared paper-wrapped flat copper wires have higher stability. By coating the surface of the aramid insulation paper with a layer of a mixed solution of silicon dioxide, silicon carbide and a rare earth oxide, the mechanical strength and oxidation resistance of the aramid insulation paper are further improved, and the service life of the prepared paper-wrapped flat copper wires is prolonged. By means of hot pressing, the acting force between aramid cellulose chains is enhanced, the combination is tighter, and the linear density is increased, such that the tearing index and tensile index of the aramid insulation paper are significantly 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.