47 results about "Nitrous acid" patented technology

The invention relates to the technical field of analytical chemistry, in particular to an ion chromatography method for separation and detection of acetate, nitrite and nitrate ions in a complex matrix culture medium. The method mainly solves the problems of insufficient separation degree, serious matrix interference, poor detection precision and reproducibility and the like when the conventional ion chromatography technology is used for detecting a complex matrix culture medium.

The present invention addresses the problem of providing an acidic cleaning solution for an aluminum-based metallic material, the acidic cleaning solution being capable of suppressing foaming while achieving favorable cleaning properties. One embodiment for solving the aforementioned problem is an acidic cleaning solution for an aluminum-based metallic material that comprises 0.01-25 g / L of at least one inorganic acid selected from the group consisting of sulfuric acid, nitric acid, nitrous acid, and phosphoric acid; 0.05-4.0 g / L of trivalent iron ions; and 0.1-10 g / L of a surfactant, wherein the surfactant includes a surfactant A: a polyoxyalkylene alkyl ether having a cloud point of 80°C or more, a surfactant B: a polyoxyalkylene alkyl ether having a cloud point of 50-60°C, and a surfactant C: a polyoxyalkylene alkyl ether having a cloud point of 40°C or less, and wherein the cloud point is measured in accordance with JIS K 3211: 1990.

A nitrogen-based gas discharge device 100 according to one aspect of the present invention includes: a green compact 111 containing a powder of a layered double hydroxide in which nitrite ions (NO2 -) are included between layers, and a powder of a reducing agent or a precursor thereof; and a gas discharge module 110 disposed so as to cover the green compact 111 and composed at least of a film 112 that is waterproof and has water vapor permeability and gas permeability. The solubility of the reducing agent in water at room temperature is 1 g / 30 mL or more and the pH of a 0.1 (w / v)% aqueous solution of the reducing agent at room temperature is 5.1 or less. The nitrogen-based gas discharge device 100 may also include a water-containing body 120 for supplying water vapor to the nitrogen-based gas discharge module 110.

The application provides a gas-phase rust-proof oil and a preparation method and a rust-proof method thereof, and is characterized in that the gas-phase rust-proof oil comprises 60-80 parts by weight of base oil, 5-20 parts by weight of an oil-soluble sulfonate rust-proof agent and 3-15 parts by weight of a gas-phase corrosion inhibitor; wherein the gas-phase corrosion inhibitor comprises a first gas-phase corrosion inhibitor and a second gas-phase corrosion inhibitor; the weight ratio of the first gas-phase corrosion inhibitor and the second gas-phase corrosion inhibitor is 1-6:1; the first gas-phase corrosion inhibitor is selected from an amine with a morpholine structure; the second gas-phase corrosion inhibitor is different from the first gas-phase corrosion inhibitor and is selected from at least one of an amine with a benzene ring structure, an amine with a nitrous acid structure and an amine with a carboxylic acid structure; the gas-phase rust-proof oil of the application not only has excellent salt spray rust-proof performance and gas-phase rust-proof performance, but also does not separate for a long time, and the appearance is transparent and turbid; in the method for preparing the gas-phase rust-proof oil, the process temperature is lower than 50 DEG C, the energy consumption is low, the production process is simple, and the time consumption is less.

The invention relates to a surface modified Fe / Cu-Co3O4 catalyst for nitrite detection and a preparation method thereof, a sensor and application, and the preparation method comprises the following steps: dissolving a cobalt source, an iron source, a copper source, urea and NH4F in deionized water, carrying out a hydrothermal reaction, washing, drying and calcining to obtain a Fe and Cu co-doped Co3O4 nanotube; and pre-hydrolyzing by using a KH792 silane coupling agent ethanol-water solution, and reacting with nanotubes to prepare the surface modified catalyst. The sensor takes carbon cloth or a screen-printed electrode subjected to ultrasonic cleaning and plasma treatment as a substrate, catalyst ink is coated to form a catalytic layer, and the catalytic layer, a platinum counter electrode and a silver / silver chloride reference electrode form a three-electrode system. Through molecular modification and material design, the interfacial force between the catalyst and nitrite is improved, the electrode stability is enhanced, and the catalyst is applied to a disposable printed electrode and portable detection equipment, so that high-sensitivity, stable and portable detection of nitrite is realized.

The invention discloses a method for reducing inhibition of free nitrous acid on toxicity of microalgae, and belongs to the technical field of biology and new medicine. In order to solve the problem that free nitrous acid (FNA) in a microalgae-nitrifying bacteria co-culture system destroys a microalgae photosynthetic system and inhibits growth, alpha-ketoglutaric acid with the final concentration of 0.5-1.0 mM is exogenously added into the microalgae-nitrifying bacteria co-culture system, so that carbon and nitrogen metabolism of microalgae is regulated and controlled, the tolerance of the microalgae to FNA is enhanced, the photosynthetic efficiency and biomass of the microalgae are remarkably improved, and the microalgae-nitrifying bacteria co-culture system can be used for preparing the microalgae-nitrifying bacteria co-culture system. The ammonia nitrogen removal rate and the system stability are improved; the method is easy and convenient to operate, low in cost, suitable for high-ammonia-nitrogen wastewater treatment and capable of assisting long-term stable operation of a phycomycete symbiotic system.

The utility model relates to gas monitoring technology, specifically provide gaseous nitrous acid analyzer, including sampling unit, separation unit and analysis unit connected in proper order, gaseous nitrous acid analyzer still includes the absorption unit connected separation unit gas export, the absorption unit includes: the both ends of jar body open, and both ends are inserted upper cover and lower cover respectively, upper cover and lower cover have gas passage respectively, sealing ring is around the outside of jar body radial, and is arranged between jar body and upper cover, and between jar body and lower cover, the filler bag is arranged in jar body, and anhydrous sodium carbonate is filled in the filler bag, the gasket is arranged in the axial direction of jar body, is extruded by upper cover and jar body one end end, and is extruded by lower cover and jar body other end end, the utility model has the advantages such as good airtightness.

The utility model relates to gas monitoring technology, specifically provide miniaturized gaseous nitrous acid analyzer, including analysis unit, the analysis unit includes light source module, flow cell and detection module, the analysis unit still includes: first optical fiber and second optical fiber have ceramic plug core and optical fiber joint respectively, ceramic plug core connects one end of three -way joint respectively, and optical fiber joint connects light source module and detection module respectively, flow cell includes composite pipe and switching module, the composite pipe includes glass tube and protection tube, glass tube sets up in the inside of protection tube, switching module connects glass tube and protection tube, and fixes on the other end of three -way joint, first ceramic plug core, first three -way joint, first switching module, composite pipe, second switching module, second three -way joint and second ceramic plug core are in straight line and set gradually. The utility model has the advantages of miniaturization, convenient maintenance etc.

The invention discloses a mass correction factor-based soluble methyl nitrite content determination method and a mass correction factor-based soluble methyl nitrite content determination system, and belongs to the technical field of methyl nitrite content determination. According to the method, an alcohol substance is adopted as a reference substance, a reliable bridge is provided for indirect quantification, and the problems that a conventional reference substance is poor in compatibility and prone to volatilization or hydrolysis are solved; secondly, an indirect quantitative system of the gaseous correction factor and the liquid reference content is established, the content of the methyl nitrite can be accurately measured without a dissolved methyl nitrite standard sample for the first time, and the technical problem that direct quantification is difficult due to lack of a special liquid standard substance in the prior art is solved.

The invention develops an axial weak coordination synthesis method for regulating and controlling a cobalt phthalocyanine molecular metal d band center based on a graphdiyne topological structure. The method is characterized in that a series of graphdiyne two-dimensional interfaces with different topological structures are obtained by regulating and controlling the arrangement and proportion of sp-and sp-hybridized carbon atoms, and the adsorption configuration of cobalt phthalocyanine molecules along the graphdiyne topological structure two-dimensional interfaces is regulated by utilizing the d-pi action between sp-carbon and a cobalt metal center. The weak coordination regulation effect of sp-carbon on the d band center of cobalt phthalocyanine metal is realized. In the process of preparing hydroxylamine from nitrate through electro-catalysis, the adsorption energy of hydroxylamine at the Co-N4 site is reduced through the axial weak coordination effect of sp-carbon; sp-carbon can be used as a transfer station for catalyzing nitrate to nitrite to assist the nitrite to be reduced into hydroxylamine at the cobalt phthalocyanine Co-N4 site, so that a full-chain series catalytic mechanism is formed.

The invention relates to the field of atmospheric environment monitoring and high-altitude sampling, and discloses an atmospheric trace nitrous acid and formaldehyde profile detection device carried by a small aircraft and a detection method. The absorption liquid is fed into the double-channel miniature spiral trapping trap through a peristaltic pump to be mixed and contacted with the sample gas to form a sample solution; a liquid storage bottle is arranged on the automatic sample disc, and the top of the first liquid inlet needle is connected with a liquid outlet of the dual-channel miniature spiral trapping trap; a color developing solution in the color developing solution storage bottle is injected into the liquid storage bottle through a second liquid inlet needle, and the constant-temperature reaction kettle controls the color developing reaction temperature to form a sample solution to be detected; a to-be-detected sample solution is pumped into the absorption cell through the liquid pumping needle, and the liquid pumping needle is driven by the liquid pumping arm to move up and down; the absorption cell is connected with a detector, and the detector is used for detecting the component concentration of the sample solution to be detected; the automatic sampler and the rapid reaction detector comprise the same automatic sample disc to realize rapid sample transfer.

The present invention relates to a method for treating an effluent from a nitriding line by membrane electrodialysis, the method comprising the application of an electric voltage between the anode and the cathode of an electrodialysis device for separating alkali metal cations and anionic species selected from nitrates, hydroxides, nitrites, carbonates and mixtures thereof.

The invention relates to a method for a palladium-catalyzed cyclization extension reaction of butadienes. Specifically, under the condition that tert-butyl nitrite is oxidized under the catalysis of palladium, the cyclopentanone compound is obtained through a ring extension reaction of butyl fulvene and water. According to the invention, green and rich water is used as a raw material, and a series of cyclopentanone compounds are obtained under mild conditions.

This invention provides a copper etching solution, its preparation method, etching method, and application. The copper etching solution comprises 1-30 parts cerium ammonium sulfate, 0-20 parts inorganic acid, 0-20 parts organic acid, and 0-90 parts water. The inorganic acid includes one or more of sulfuric acid, phosphoric acid, hypochlorous acid, chloric acid, boric acid, carbonic acid, nitric acid, nitrous acid, and hydrochloric acid. The organic acid includes one or more of citric acid, acetic acid, tartaric acid, malic acid, formic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, glycolic acid, acrylic acid, methacrylic acid, lactic acid, gluconic acid, maleic acid, benzoic acid, and salicylic acid. The copper etching solution of this invention exhibits good etching properties for copper and minimal damage to nickel-chromium alloys.

A method for extracting copper from sulphide mineral ore, comprising the following steps: stacking the ore to form a pile (heap), a leaching step, irrigating the pile with a first irrigating solution containing an acidic nitrate solution and nitrite, thereby causing the oxidation of sulfide minerals inside the pile, oxidation of gaseous nitrogen oxide released during the oxidation of sulfide minerals inside the pile with oxygen to form nitrogen dioxide, and hydrolysis of nitrogen dioxide to form nitric acid and / or nitrous acid in the first irrigating solution inside the pile, to continue the leaching stage and reduce nitrogen oxide losses from the pile.

The application relates to the technical field of nitrite synthesis, and discloses a synthesis method and a synthesis device of alkyl nitrite. The synthesis method comprises the following steps: firstly, mixing gaseous nitric oxide and gaseous oxygen to obtain a mixture through a first reaction; and then, mixing the mixture with alkyl alcohol to obtain alkyl nitrite through a second reaction. The synthesis method greatly shortens the reaction time, increases the yield of alkyl nitrite, does not have a complicated post-treatment process and a large amount of by-product nitric acid, and is beneficial to cost saving and time saving.

The invention relates to a preparation method of 3-bromo-2-methyl-6-methylsulfonyl benzaldoxime, and belongs to the technical field of pesticides. The preparation method comprises the following steps: by taking 2, 3-dimethyl-4-methylsulfonyl bromobenzene as a raw material and adopting an organic solvent, adding a metal salt catalyst and N-hydroxyphthalimide, dropwise adding n-butyl nitrite into a system at a certain temperature, carrying out a heat preservation reaction after dropwise adding, and carrying out post-treatment after the reaction is finished, so as to obtain the 3-bromo-2-methyl-6-methylsulfonyl benzaldoxime. According to the invention, the dosage of the oximation reagent n-butyl nitrite is reduced, and the yield of oximation reaction is improved. According to the method, the reaction conditions are mild, low-temperature dropwise adding and high-temperature reaction are converted into normal-temperature reaction, meanwhile, the reaction time is shortened, and the production energy consumption is reduced.

The utility model relates to the field of environment monitoring technology application, in particular to a portable pollution source emission on-line measurement device which comprises a tail gas sampling and pretreatment module, a formaldehyde and nitrous acid on-line analysis module, a conventional gas expansion module and a data acquisition and main control module, the tail gas sampling and pretreatment module is respectively connected with the formaldehyde and nitrous acid online analysis module and the conventional gas expansion module, the formaldehyde and nitrous acid online analysis module is connected with the data acquisition and main control module, and the conventional gas expansion module is connected with the data acquisition and main control module. The automobile exhaust emission flow temperature is monitored, formaldehyde and nitrous acid are measured through the formaldehyde and nitrous acid on-line analysis module, data recording is carried out through the conventional gas expansion module, and finally the data of formaldehyde and nitrous acid are stored and monitored through the data acquisition and main control module. Therefore, active components such as formaldehyde and nitrous acid discharged from the motor vehicle tail gas road can be measured.

The invention relates to the technical field of chemical synthesis, and particularly discloses a method for preparing nitric acid and nitrous acid under a catalyst-free condition. The method comprises the following steps: atomizing deionized water to form micro-droplets, mixing the micro-droplets with high-purity nitrogen to construct a nitrogen-water micro-droplet mixed system, applying a radio frequency electric field to the system at normal temperature and normal pressure to perform micro-plasma discharge treatment, enabling nitrogen and water to react under a catalyst-free condition to generate nitric acid and nitrous acid, and collecting products through an absorption device. By adopting the technical scheme, green, low-carbon and high-selectivity synchronous synthesis of nitric acid and nitrous acid can be realized, the energy consumption and carbon emission are remarkably reduced, the process flow is simple, the raw materials are cheap, the operation is safe, the method can be coupled with a renewable energy power system, and the method is suitable for the fields of chemical fertilizers, medicines, electronic chemicals and the like.

An atomizing method using an atomizer in which peroxynitrous acid is sustainedly generated through plasma activated mist, pH of the plasma activated mist being in a range from 2 to 5, wherein the plasma activated mist has been generated from an aqueous solution containing nitrite, concentration of the nitrite being in a range from 10 micromolar to 10 milli-molar.

The invention belongs to the technical field of preparation of deuterated organic compounds, and particularly relates to a synthetic method of deuterated chlorobenzene-D4, which comprises the following steps: reacting deuterated aniline, benzyltriethylammonium chloride and tert-butyl nitrite to prepare the deuterated chlorobenzene-D4. According to the method, the synthesis process is mild and easy to control, the requirement for equipment is low, the raw materials are low in price and high in utilization rate, and the purity and the deuteration rate of the prepared deuterated chlorobenzene-D4 are high.

The present invention belongs to the field of dyeing and finishing. Disclosed is a reactive dyeing method for black protein fibers based on coupled color development. The method comprises the following steps: modifying protein fibers by using isatoic anhydride; diazotizing the obtained modified protein fibers by using nitrous acid, so as to obtain diazotized protein fibers; and reacting the diazotized protein fibers with an acidic solution containing a coupling component, so as to generate a colored substance containing an azo structure. Black protein fibers dyed by using the method exhibit a good relative fixation rate, up to 95%; and the dyed fibers have good color fastness and durability.

The present invention provides a method for generating nitrite and / or nitrate ions from a nitrate ester and a method for detecting nitrate esters in a mixture by generating and detecting nitrite and / or nitrate ions.

The disclosure relates to methods of producing nitric oxide (NO) gas that is administrable without specialized equipment and does not provide nitrogen dioxide (NO2) gas. The methods comprise combining a nitrate and / or nitrite anion and an elemental metal in an acidic solution in a vessel capable of housing liquid and gas constituents, wherein NO gas is produced by the reaction of the nitrate and / or nitrite anion and the elemental metal in the acidic solution. The method further comprises administering the NO gas produced to the subject via inhalation. Also described are compositions and kits for improved delivery of NO gas.

This invention belongs to the field of organic synthesis, specifically relating to a green and efficient synthesis method for m-trifluoromethylacetophenone oxime. The specific steps are as follows: first, m-trifluoromethylaniline is added to a nonpolar solvent and reacts with nitrite ester under the action of an organic acid to generate a diazonium salt. Then, under the combined action of a phase transfer catalyst and a copper salt catalyst, it reacts with acetaldehyde oxime to generate m-trifluoromethylacetophenone oxime. After heating and filtering the copper salt catalyst, the mixture is cooled and crystallized to obtain m-trifluoromethylacetophenone oxime with a content of over 98% and a yield of over 90% based on m-trifluoromethylaniline. The above synthesis method generates less waste, has high atom utilization, high reaction yield, simple operation, strong process stability, and is easy for industrial production.

This invention discloses a sensitive fluorescence sensor for detecting NO in ham sausage samples. 2‑ The method belongs to the field of analytical detection. The steps are as follows: 1. Prepare carbon dots using citric acid and cauline as precursors; 2. NO in the carbon dots 2‑ The addition of [a specific substance] will quench fluorescence through dynamic quenching and diazotization effects, based on which NO [a specific substance] can be constructed. 2‑ Standard curves of NO concentration and fluorescence quenching degree were obtained, and the NO concentration in ham sausage samples was determined. 2‑ The concentration of NO. This invention is the first to use a sensitive fluorescence sensor to sequentially detect the concentration of NO. 2‑ It enables quantitative detection of substances and is simple, safe, and efficient, making it suitable for routine analysis.

The application discloses a quantitative method for trace gaseous nitrous acid generated by photolysis, which comprises two modes. Mode one uses a chemical ionization mass spectrometer in positive ion mode to measure the concentration change of volatile organic compounds (VOC) reacted with hydroxyl radicals (·OH) after a switch mercury lamp to quantify the ·OH concentration generated by the mercury lamp irradiation, and further makes nitric oxide (NO) react with ·OH to generate gaseous nitrous acid (HONO), so that the generated concentration of HONO is approximately equal to the change concentration of VOC measured by the mass spectrometer under the condition of NO excess. Mode two uses a NO analyzer to measure the concentration change of NO reacted with ·OH before and after the mercury lamp is turned on to quantify HONO and ·OH, and the ·OH concentration generated by the mercury lamp irradiation and the HONO concentration generated under the condition are both approximately equal to the NO concentration change measured by the NO analyzer.

A method for the production of a flat steel product including at least the following steps, completed in a continuous process:providing a flat steel product, wherein a protective metal layer of Zn, a Zn—Al alloy, a Zn—Mg alloy or a Zn—Mg—Al alloy is applied to at least one side by hot dip coating;at least partly removing a native oxide layer present on the surface of the protective metal layer by wetting this surface with an acidic solution of sulfuric acid, sulfurous acid, hydrochloric acid, phosphoric acid, phosphonic acid, nitric acid, formic acid, oxalic acid, acetic acid, citric acid, malic acid, tartaric acid, nitrous acid or hydrofluoric acid;activating the surface of the protective metal layer by applying an aqueous activation solution to the surface of the protective metal layer;and phosphating the activated surface of the protective metal layer by applying an aqueous phosphating solution to the activated surface.

The invention relates to the technical field of inorganic functional materials, in particular to a bismuth hexanitrite octahydrate crystal adsorbent as well as a preparation method and application thereof.The chemical formula of the bismuth hexanitrite octahydrate crystal adsorbent is Bi2 (NO2) 6. 8H2O, the bismuth hexanitrite octahydrate crystal adsorbent belongs to a triclinic system, the space group is P-1, and the structural formula is shown in the description. The photocatalyst has a three-dimensional open skeleton structure constructed by nitrite bridged bismuth ions and a crystal water hydrogen bond network. According to the preparation method, bismuth nitrate pentahydrate and 4-aminopyridine quaternary ammonium salt are subjected to solvothermal synthesis in a hydrobromic acid ethanol system and are combined with a room-temperature crystallization method, the preparation process is simple, the condition is mild, the cost is controllable, and the preparation method has remarkable industrial application potential in the field of deep decolorization treatment of industrial printing and dyeing wastewater.

The utility model relates to a gas monitoring technology, and particularly provides a gaseous nitrous acid analyzer with a field calibration function, which comprises a sampling unit, a separation unit and an analysis unit which are connected in sequence, the gas-state nitrous acid analyzer also comprises a standard gas generation unit; the standard gas generation unit comprises a spiral heat conduction pipe which is cast in a base body by a heat conduction medium; the TEC is fixed on the base body, and the temperature sensor is arranged in the base body. The device has the advantages of low energy consumption and the like.