633 results about "Potassium hydroxide" patented technology

The invention discloses a preparation process of a waste concrete recycled aggregate gypsum-based wall material, which comprises the following steps: (1) mixing a water repellent agent with an anhydrous solvent to obtain a pretreating agent, and then adding concrete recycled aggregate for standing; and separating out the recycled aggregate and drying the recycled aggregate to obtain the pretreated recycled aggregate. (2) calcining the magnesium oxide whisker, and then adding the obtained calcined whisker into an ethanol solution of polyethylene glycol to form a suspension; and spraying the suspension on the continuously stirred pretreated recycled aggregate, and then carrying out heating and stirring treatment to obtain the modified recycled aggregate. And (3) uniformly stirring ardealite powder, silica fume, potassium hydroxide powder and fine aggregate, then adding water, a retarder and a water reducing agent, uniformly stirring, then adding the modified recycled aggregate, and uniformly stirring, thereby obtaining the product. The process provided by the invention not only reduces the adverse effect of the recycled aggregate on the gypsum-based material, but also improves the water resistance of the gypsum-based material and enhances the mechanical strength.

The invention relates to the technical field of molten salt, in particular to nitro binary molten salt and a preparation method thereof. The preparation method comprises the following steps: mixing sodium carbonate and a potassium hydroxide solution, and then adding a starch-based grafted crystal inhibitor to inhibit crystallization; adding a nitric acid aqueous solution in two stages, and introducing eutectic seed crystals to guide nucleation at the end of the first stage; crystal distribution is optimized through falling film evaporation and concentration and setting of partial reflux; and after spraying granulation, carrying out short-time melting reforming and controlled cooling in an inert atmosphere. According to the method, the composition uniformity and the structural stability of the molten salt are remarkably improved, so that the product has a melting point close to a theoretical eutectic point, low supercooling degree, high melting latent heat and excellent thermal cycling stability and corrosion resistance, and is suitable for an industrial heat storage system running for a long time.

The invention provides a charcoal-loaded iron-based catalyst suitable for heterogeneous catalysis as well as a preparation method and application of the charcoal-loaded iron-based catalyst. The preparation method comprises the following steps: firstly, activating and modifying tea leaves by adopting a potassium hydroxide solution, and then carrying out heat-preservation pyrolysis in a carbon dioxide atmosphere to obtain tea-leaf-based biochar; uniformly mixing an iron source, a manganese source, a cerium source and a citric acid solution; adding tea-based biochar, uniformly mixing, and drying to obtain a precursor; and heating the precursor to 400-650 DEG C, and carrying out heat preservation and pyrolysis to obtain the biochar-loaded iron-based catalyst. The biochar-loaded iron-based catalyst has excellent degradation and removal effects and cycle stability on xylene.

The invention discloses a preparation method of high-viscosity cationic starch, which belongs to the technical field of modified starch, and comprises the following steps: crosslinking epichlorohydrin, ball-milling and cationizing; the epoxy chloropropane crosslinking comprises the following steps: mixing starch, calcium hydroxide and deionized water, stirring at 40-50 DEG C, adding sodium stearoyl lactylate, stirring at 50-55 DEG C, naturally cooling to room temperature, adding sodium chloride and epoxy chloropropane, stirring, dropwise adding a potassium hydroxide aqueous solution, stirring, adjusting the pH value to 6, filtering, taking filter residues, washing and drying to obtain crosslinked starch; in the step of ball milling, calcium hydroxide, sucrose fatty acid ester SE-11 and deionized water are mixed and then subjected to ball milling, and a ball-milled material is obtained; the prepared high-viscosity cationic starch is high in paste liquid viscosity and cationic substitution degree, good in paste liquid viscosity stability, uniform in substitution degree and paste liquid viscosity, high in reaction efficiency in cationization and low in alkali consumption.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a silicon-carbon negative electrode material based on spherical-like resin porous carbon and a preparation method thereof.The method comprises the steps that resin and an emulsifier are fully reacted, solid resin microspheres are obtained after treatment, then high-temperature carbonization is conducted, potassium hydroxide activation is conducted after smashing, and the spherical-like resin porous carbon-based silicon-carbon negative electrode material is obtained; and carrying out acid washing to obtain the spheroidic porous carbon. And the silicon-carbon negative electrode material is obtained after vapor deposition, and the material is particularly suitable for a high-energy-density power battery.

The invention relates to the technical field of preparation of composite carbon sources, and discloses a method for preparing a micromolecular composite carbon source by using soapstock acidified leftovers, which comprises the following steps: pretreatment: centrifugally separating the soapstock acidified leftovers, recovering crude fatty acid, and regulating the pH value of the water phase to 5.0-6.0 by using an alkaline regulator, performing enzymolysis, namely adding compound protease into the pretreated water phase, performing enzymolysis reaction at 45-55 DEG C, performing organic acid hydrolysis, namely adding small molecular organic acid into a system subjected to enzymolysis, adjusting the pH value of the system to 2.0-4.0, performing hydrolysis reaction at 85-100 DEG C, performing neutralization and post-treatment, cooling the system after the hydrolysis is completed, neutralizing the pH value of the system to 5.5-6.5 by adopting an alkaline substance, and performing post-treatment to obtain a finished product. And filtering to obtain the small molecular carbon source. The alkaline substance is potassium hydroxide, ammonia water or urea. According to the method for preparing the micromolecular composite carbon source by utilizing the soapstock acidified leftovers, the waste liquid, which is the soapstock acidified leftovers generated in the grease refining process and is difficult to biochemically treat, can be converted into the micromolecular composite carbon source with high market value.

The invention discloses vinyl fluorine-containing polysiloxane and a preparation method thereof, and relates to the technical field of organic silicon materials. According to the invention, high-activity fluorine-containing potassium hydroxide silanolate is used as a catalyst to realize high-efficiency catalysis; d3F serves as a main monomer, D3Vi serves as a comonomer, deionized water is introduced for the first time to serve as a retarder, and implosion is effectively inhibited; vinyl dimethyl ethyoxyl silane is used as an end-capping reagent for the first time, end group vinylation is synchronously realized, and end group and side chain divinyl polysiloxane is prepared; through cooperation of ring-opening polymerization and condensation polymerization, the reaction process is mild and controllable, the product viscosity is controllable, the crosslinking activity is high, and the application range is remarkably widened.

The invention discloses a potassium propionate continuous synthesis process, and relates to the technical field of potassium propionate synthesis, the process comprises the following steps: S1, raw material pretreatment: selecting fermentation waste liquid containing propionic acid and acetic acid and potassium ore leaching liquid containing potassium hydroxide and potassium carbonate as composite raw materials, adding a composite chelating agent into the potassium ore leaching liquid, and uniformly stirring; according to the method, the composite raw material system composed of the fermentation waste liquid and the potassium ore leaching liquid is adopted, and the composite chelating agent is added, so that resource utilization of industrial waste is achieved, the raw material cost is reduced, meanwhile, impurities are prevented from interfering with continuous reaction, and through gradient temperature control-pressure cooperative regulation and linkage regulation of the PLC system, the yield is increased. The problem of product deliquescence caused by local overheating is solved, volatilization loss of propionic acid is reduced, the adaptability of the technology to raw material batch fluctuation is improved through raw material concentration online detection and dynamic parameter adaptation, the continuous production stability is guaranteed, and finally synchronous improvement of the potassium propionate synthesis efficiency and the product quality is achieved.

The invention relates to the technical field of potassium formate preparation, in particular to a device and method for preparing potassium formate through potassium hydroxide, surrounding feeding, compression forming and double cutting are integrated, potassium hydroxide powder enters a surrounding mechanism through an input pump, raw materials are randomly fed into a compression shell, accumulation is effectively avoided, a compression piston is driven to ascend and descend in a reciprocating mode, and the potassium formate is prepared. And the powder is extruded into a compact cylinder, and feeding and compression are synchronously controlled, so that the continuous process is ensured. The double-cutting system accurately controls the height of a movable blade through an adjusting support so as to lock the total volume of raw materials, an adjustable blade and a bottom supporting base alternately move, a column body is divided into multiple sections of small columns, the reaction surface area is increased through geometric progression, and accurate regulation and control of the reaction rate are achieved. According to the device, quantitative control of the feeding amount, dynamic adjustment of the reaction rate and cleaning of the operation environment are achieved, and the accuracy and safety of potassium formate preparation are improved.

The invention provides a multi-metal / carbon coated iron-chromium flow battery electrode material and a preparation method thereof, and belongs to the technical field of iron-chromium flow battery energy storage. The preparation method comprises the following steps: carrying out pre-oxidation treatment, carbonization treatment and graphitization treatment on a precursor fiber felt to obtain a graphite felt; the preparation method comprises the following steps: dipping a graphite felt in a potassium hydroxide solution, then drying and carrying out primary calcination treatment, dipping an activated felt in a metal salt solution, then drying and carrying out secondary calcination treatment, dipping a multi-metal loaded activated felt in a dopamine solution containing a conductive agent, then adding a buffer solution until the pH value of the solution is 8-10 so as to enable dopamine to be self-polymerized, and then carrying out tertiary calcination treatment so as to obtain the multi-metal loaded activated felt. The multi-metal / carbon coated iron-chromium flow battery electrode material is obtained. The multi-metal / carbon coated iron-chromium flow battery electrode material disclosed by the invention has high hydrophilicity, high hydrogen evolution overpotential, high specific surface area, high energy efficiency and long cycle stability.

The invention relates to the field of nuclear power operation, in particular to a control method for quantitative ammonia potassium saturation of cation resin of a primary loop purification system of a nuclear power plant. The method comprises the following steps: before starting ammonia-potassium saturation, calculating the total amount of ammonia absorbed by resin, the total amount of potassium absorbed by resin and the ideal concentration of a potassium hydroxide solution by utilizing the total exchange amount of nuclear-grade cation resins in a series I and a series II and the ammonia and potassium selectivity coefficients of the nuclear-grade cation resins; the flow of the first series and the flow of the second series are adjusted, the theoretical ammonia adding amount of the first loop under different flows of the second series is calculated, and continuous ammonia adding is conducted on the first loop with the theoretical ammonia adding amount as the target; when the series of diamino potassium is saturated, sampling and analyzing the total alkali metal content and the ammonia content from the outlets of the primary loop and the series II, and calculating and adjusting the adding amount and the frequency of the potassium hydroxide solution to ensure that the total alkali metal concentration of the main loop is in the area A and does not deviate; after the potassium ammonia saturation of the series II is finished, stopping the operation of the series I, calculating the required ammonia adding amount under the normal working condition, timely adjusting the continuous ammonia adding amount of the loop I, quitting the series I, and keeping the operation of the series II. According to the invention, smooth implementation of saturation of series of diamino potassium and safety of primary loop water quality are ensured.

The application provides an ultra-high performance concrete and a preparation method thereof, and the concrete comprises the following raw materials in parts by weight: cement 260-280 parts, modified quartz sand powder 120-160 parts, modified steel fiber 8-15 parts, fly ash 20-26 parts, polycarboxylic acid water reducing agent 7-12 parts, EVA emulsion 16-24 parts, alkali-resistant glass fiber 4-7 parts, and water 140-180 parts. The preparation method of the modified steel fiber is as follows: the steel fiber is soaked in a potassium hydroxide solution and then dried, the dried steel fiber is added into a calcium hydroxide slurry, potassium carbonate is added for a first stirring reaction, a mixed solution of nano-SiO2 and a coupling agent is further added for a second stirring reaction, filtration and drying are performed, and the modified steel fiber is obtained. The ultra-high performance concrete prepared by the application has scientific proportioning of various raw materials, good toughness, strength and crack resistance, and can effectively improve the service life of the concrete.

The application discloses a capacitive activated carbon purification method and relates to the technical field of activated carbon material preparation.The application comprises the following steps: physically removing magnetic substances from the activated sample; adding potassium hydroxide to the sample, and then performing ultrasonic treatment and mechanical heating and stirring; performing water washing after temperature reduction, and then performing dehydration; adding hydrochloric acid to the sample, and then performing ultrasonic treatment and mechanical heating and stirring; performing secondary water washing after temperature reduction, and then performing dehydration; drying; and performing quality inspection and subpackaging.The method disclosed by the application can improve the purity of activated carbon by physically removing iron, ultrasonic treatment combined with mechanical stirring, and water-heat coupling linkage cooperation, greatly shorten the production cycle, and is suitable for a wide range of applications.

The application discloses a preparation method of a cobalt-based biochar composite material and application of the cobalt-based biochar composite material in persulfate oxidation, and comprises the following operation steps: a proper amount of sodium alginate is weighed, calcined, activated and dried to obtain a derived original biochar SA; after the SA is used as an adsorbent to adsorb cobalt ions, drying is performed to obtain a cobalt-containing biochar CoSA; the CoSA is uniformly ground with urea, pyrolysis is performed, washing, filtering and drying are performed, and vacuum drying is performed to obtain a cobalt-based biochar composite material CoNBC based on sodium alginate; and the activation method is that the SA is mixed with potassium hydroxide, ground in a jade mortar for 5-30 min, and then activated in ultrapure water for 1-8 h.The raw material used in the application is environment-friendly, the preparation process is simple, the cobalt-based biochar composite material obtained has excellent catalytic capacity for persulfate, can effectively control the precipitation of transition metals, reduces pollution, and greatly improves the utilization rate of metal elements.

The invention belongs to the technical field of fine chemical synthesis, belongs to a nonionic short fluorine chain surfactant, and relates to a preparation method of a fluorinated polyether surfactant. The preparation method comprises the following steps: reacting trimethylolethane with a hydrogen bromide acetic acid solution to prepare an intermediate 1; reacting the intermediate 1 in an alkaline environment without an organic solvent to prepare an intermediate 2; reacting the intermediate 2 with pentafluoropropanol under the action of potassium hydroxide and a catalyst 1 to prepare a fluorinated monomer; finally, the fluorinated monomer is subjected to ring opening polymerization under the action of an initiator and a catalyst 2, and the fluorinated polyether type surfactant is prepared. The method has the advantages of easily available raw materials, mild reaction conditions, simple synthesis, low cost, high yield and short fluorine chain of the product, can replace a long-chain fluorine-containing surfactant which is difficult to degrade, and can be used as an additive in the fields of photoresists, coatings, adhesives and the like. The surface tension can be obviously reduced, the surface defects of a coating can be reduced, and the appearance can be improved by adding a very small amount of the surface tension reducing agent.

The invention relates to the technical field of lithium ion battery negative electrode materials, in particular to a preparation method of a high-rate silicon-carbon composite negative electrode material. The silicon-carbon composite material takes a porous carbon material as a substrate, and is compounded by depositing a silicon source into the porous carbon substrate in a chemical vapor deposition manner; according to the excellent fast charging performance, the porous carbon substrate is prepared by adopting a tin source and potassium hydroxide synergistic activation strategy, and the limitation of a traditional single alkali activation (such as KOH) or metal auxiliary activation method is broken through. Through the synergistic effect of the two, a hierarchical pore structure with micropore-mesopore gradient distribution is realized, the silicon deposition bearing capacity and ion transport dynamics performance of porous carbon are remarkably improved, and a structural basis is provided for subsequent uniform deposition of silicon and rapid migration of lithium ions.

The application discloses a low-temperature-resistant electrolyte for alkaline batteries and a preparation method thereof, and relates to the technical field of electrolytes. The application comprises the following raw materials in mass fraction: glycerol triacetate 11-13 parts, potassium hydroxide aqueous solution 100-150 parts, fluorine-containing additive 1-5 parts, and organic dispersion 21.3-28 parts; the organic dispersion is prepared from ethylene glycol, tetrabutylammonium trifluoromethanesulfonate, hybrid nanosheet and glycerol triacetate. The hybrid nanosheet prepared from hexagonal boron nitride, cerium ammonium nitrate, urea and polyethylene glycol 400 effectively improves the ion conductivity and cycle stability maintenance rate of the electrolyte at low temperature. The introduction of the components such as glycerol triacetate and fluorine-containing additive in the application further improves the performance maintenance rate of the electrolyte at low temperature, and simultaneously reduces the viscosity of the electrolyte at low temperature. Therefore, the application has a more extensive application prospect.

This invention provides a micro-arc oxidation electrolyte for magnesium alloy surface treatment and a method for preparing a micro-arc oxidation film. The micro-arc oxidation electrolyte is an aqueous solution containing sodium silicate, sodium hydroxide, potassium fluoride, and titanium boron carbon nitride conductive nanoparticles; or, an aqueous solution containing sodium silicate, potassium hydroxide, potassium fluoride, and titanium boron carbon nitride conductive nanoparticles. This invention also discloses a method for preparing a micro-arc oxidation film using the aforementioned micro-arc oxidation electrolyte for magnesium alloy surface treatment. The micro-arc oxidation electrolyte of this invention contains conductive ceramic nanoparticles—titanium boron carbon nitride conductive nanoparticles. Using these nanoparticles to perform a micro-arc oxidation reaction on the magnesium alloy surface can improve the microstructure of the micro-arc oxidation film, while simultaneously enhancing the corrosion resistance and wear resistance of the magnesium alloy after micro-arc oxidation treatment, significantly improving the surface protection capability of the magnesium alloy, and extending its service life.

The application discloses a non-metallic mineral powder ball preparation method for loading plant nutrient factors, and comprises the following steps: kaolin is added into hydrochloric acid and stirred, washed with water, calcined at 400-460 DEG C for 1-2h, then added into water with gelatinized starch and stirred, added with silane coupling agent KH560 and continuously stirred, filtered, washed, dried, added with polyvinyl alcohol and pH regulator and stirred to obtain premix; fly ash and refined sugar are uniformly mixed and formed to obtain pretreated fly ash; potassium hydroxide is added into sodium silicate solution and stirred uniformly, then hydroxypropyl chitosan is added and stirred to obtain a precursor solution; the precursor solution is uniformly poured on the surface of the pretreated fly ash, and then placed, solidified, ultrasonic washed and dried to obtain a sponge-like carrier; field soil, organic fertilizer and plant fermented straw are added into a high-speed pulverizer and pulverized, and sieved to obtain granules; the premix and the sponge-like carrier are added and uniformly mixed, and then formed to obtain a seedling raising substrate.

The application provides a Y molecular sieve adsorbent and a preparation method and application thereof. The preparation method comprises the following steps: mixing a pore-expanding agent and a Y molecular sieve, and calcining to obtain the Y molecular sieve adsorbent; wherein the pore-expanding agent comprises any one or a combination of at least two of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, a sodium hydroxide solution, a potassium hydroxide solution, lactic acid, ammonia water, malic acid, succinic acid, propionic acid, formic acid, sodium carbonate, amino acid, ascorbic acid or sodium silicate. The application mixes the pore-expanding agent and the Y molecular sieve, and then performs calcination, so that the pore-expanding agent is effectively eliminated, the pore of the Y molecular sieve adsorbent is improved, the Y molecular sieve adsorbent with excellent adsorption performance is prepared, and efficient adsorption of carbon dioxide is realized. The preparation process of the Y molecular sieve adsorbent is simple, the preparation process cost is low, and the Y molecular sieve adsorbent has the advantages of green environmental protection.

A process for producing lithium hydroxide monohydrate from lithium chloride, the process comprising: (a) adding an aqueous potassium ion and hydroxide ion-containing solution to an aqueous lithium chloride-containing solution, thereby obtaining a mixture comprising lithium hydroxide, potassium chloride and water, (b) selectively precipitating potassium chloride from the mixture, thereby obtaining potassium chloride precipitate and a first mother liquor solution, (c) separating the potassium chloride precipitate from the first mother liquor solution, (d) processing the potassium chloride precipitate to obtain an aqueous potassium hydroxide-containing solution, (e) adding the aqueous potassium hydroxide-containing solution to the separated first mother liquor solution, thereby obtaining a potassium hydroxide-enriched first mother liquor solution, and (f) selectively precipitating lithium hydroxide monohydrate from the potassium hydroxide-enriched first mother liquor solution, thereby obtaining lithium hydroxide monohydrate precipitate and a second mother liquor solution.

The invention belongs to the technical field of electrocatalytic carbon dioxide reduction catalysts, and discloses a silver-based catalyst suitable for fluctuating carbon dioxide electrolysis and a preparation method of the silver-based catalyst. The preparation method comprises the following steps: uniformly and continuously dropwise adding a potassium hydroxide solution into a silver nitrate solution to prepare a silver oxide catalyst, and further applying a constant reduction current to the silver oxide catalyst in the presence of carbon dioxide gas for in-situ reduction to prepare the quintuple twin crystal silver-based catalyst. The preparation method disclosed by the invention combines precipitation titration and in-situ electroreduction methods, and has the characteristics of simplicity in operation, greenness, high efficiency and suitability for mass production; meanwhile, the catalyst can maintain high selectivity to carbon monoxide products in an extremely wide potential window range of 3V when being used in an electro-catalysis carbon dioxide conversion reaction, and is very suitable for being directly matched and coupled with fluctuating renewable energy sources.

This invention belongs to the field of mineral flotation technology, and discloses a flotation collector for non-ferrous metal sulfide ores, its preparation method, and its application. The collector uses O,O-dialkyldithiophosphate as a starting material, and reacts sequentially with a halocarboxylic acid ester, hydrazine hydrate, potassium hydroxide, and carbon disulfide in anhydrous ethanol in a three-step reaction to obtain the target product, O,O-dialkyldithiophosphate hydrazide-N′-dithiocarbamate potassium. Its molecular structure simultaneously contains three active groups: a dithiophosphate group, an hydrazide group, and a dithiocarbamate group. This invention achieves efficient process connection and smooth transition by optimizing the material ratio, temperature, and time of each reaction step, and has advantages such as mild reaction conditions, simple operation, few side reactions, high yield, and stable product. The prepared collector exhibits excellent collecting performance and good selectivity for non-ferrous metal sulfide ores such as chalcopyrite, and is suitable for widespread application in sulfide ore flotation processes.

The invention discloses a method for detecting phosphate impurities, namely diethyl phosphoacetic acid and diethyl phosphate, in afatinib, and establishes a simple and sensitive ion chromatography detection method based on the hydrolysis property of a phosphate compound under an alkaline condition. Sodium hydroxide or potassium hydroxide solution-water is used as a mobile phase for isocratic or gradient elution, and a conductivity detector is used for detection. According to the present invention, the accurate quantification of the impurities in the afatinib is achieved, the detection speed is fast, the cost is low, the operation is simple, and the good specificity, the sensitivity, the precision and the accuracy are provided, such that the product quality of the afatinib maleate bulk drug synthesized by using the diethyl phosphoacetic acid as the starting material and the related preparation can be further ensured.

The application relates to a low-eutectic solvent-based gel electrolyte, a preparation method and a zinc-air battery, and belongs to the technical field of metal-air batteries. Choline chloride and 2-methyl-1,3-propanediol are prepared into a deep eutectic solvent, then zinc acetate dihydrate solution, acrylic acid monomer, a crosslinking agent and a photoinitiator are sequentially added, the mixture is uniformly mixed, photopolymerization is carried out, and a low-eutectic solvent-based gel is obtained. The electrolyte is obtained by soaking the gel in a mixed solution of potassium hydroxide and zinc salt. The zinc anode protection capability and the low-temperature adaptability of the gel electrolyte can be improved. The gel electrolyte is assembled into a zinc-air battery together with a zinc electrode and an air electrode, and the cycle life and the operation stability of the battery in a low-temperature environment can be effectively improved.

A method for mineralizing a perfluorinated compound by using a molten alkali is provided. The method includes the following steps: mixing NaOH and KOH to obtain a mixed alkali, and heating the mixed alkali to a temperature of 150° C. to 300° C. to a molten state obtain a molten alkali; adding the perfluorinated compound to the molten alkali to obtain a molten reaction system, and holding the molten reaction system at the temperature of 150° C. to 300° C.; and subjecting the molten reaction system to reaction for 15 min to 60 min to mineralizing the perfluorinated compound.

The invention relates to the technical field of analytical chemistry detection, in particular to a method for determining trace nitrite in pharmaceutic adjuvants.The method comprises the steps that an acetonitrile solution, a potassium hydroxide solution, a phosphate buffer solution, a sulfuric acid solution, a 2, 3-diaminonaphthalene solution and a reference substance working solution are provided; the method comprises the following steps: preparing a standard curve solution and a test sample solution, and carrying out ultra-high performance liquid chromatography-tandem mass spectrometry analysis detection: respectively carrying out sample injection detection on the test sample solution and the prepared standard curve solutions with different concentrations under preset chromatographic conditions and mass spectrometry conditions, recording detection results of the standard curve solutions with different concentrations to make a standard curve, and calculating the content of nitrite in the test solution by adopting a standard addition method according to the standard curve and the detection result of the test solution. The method disclosed by the invention can be used for rapidly determining trace nitrite in a drug sample, and can be used for determining the trace nitrite in pharmaceutical adjuvants and detecting the nitrite in drugs.

The invention discloses a preparation method of a barium-based hydrophobic oxygen production molecular sieve, which comprises the following steps: S1, fully mixing a sodium metaaluminate solution, potassium hydroxide, sodium silicate and deionized water, and carrying out hydrothermal reaction and centrifugal calcination to obtain a sodium-based molecular sieve; s2, uniformly mixing the sodium-based molecular sieve and a barium chloride solution, and performing hydrothermal reaction to obtain a barium-based molecular sieve; s3, mixing and stirring the barium-based molecular sieve and a phenyltrimethoxysilane solution to obtain the barium-based hydrophobic oxygen generation molecular sieve. The hydrophobicity of the molecular sieve can be improved, and the adsorption efficiency and the service life of the molecular sieve in a high-humidity environment are effectively improved.

The invention discloses a kHz crystal frequency electronic component production process, and belongs to the technical field of electronic component manufacturing. Comprising the steps of wafer cleaning, film coating, coarse adjustment, wafer feeding, curing, frequency adjustment, press sealing, pin cutting, backflow, wafer sleeving, aging and the like. A compound cleaning solution containing potassium hydroxide, EDTA (Ethylene Diamine Tetraacetic Acid) tetrasodium, sodium silicate and methyl isobutyl ketone is adopted for wafer cleaning, and residual impurities are removed in a gradient manner through five steps of processes of pre-chelation, main cleaning, solvent replacement, weak acid washing and ultrapure water washing in combination with outlet solution monitoring; (2) pre-cleaning by argon-oxygen mixed plasma before coating, activating by pure argon, and preparing a protective film by adopting a composite barrier liquid containing KR-38S, electronic-grade nano Al2O3 and a BHT hydrogen polymerization inhibitor; in the aging stage, a nitrogen-hydrogen-argon mixed atmosphere is adopted, and a honeycomb porous guide plate made of a quartz material is matched, so that the stability of an aging environment is optimized. The technical problems of wafer cleaning hidden residues, silver layer cross-process structure damage, poor frequency stability and the like in the prior art can be effectively solved.

This invention relates to the field of fertilizer technology, specifically to an organic liquid fertilizer based on straw enzymatic hydrolysate and its preparation method. The method includes: pretreating corn straw with potassium hydroxide, followed by enzymatic hydrolysis with cellulase and xylanase to obtain the enzymatic supernatant; sequentially treating the supernatant with an ultrafiltration membrane with a molecular weight cutoff of 3000 Da and a nanofiltration membrane with a molecular weight cutoff of 500 Da to collect oligosaccharides with a molecular weight window of 500-3000 Da; partially stabilizing the reducing end of the oligosaccharides with sodium borohydride; pre-complexing with boric acid at pH 8.4-8.8; then sequentially adding relatively low molecular weight sodium polyglutamate, calcium chloride dihydrate aqueous solution, and ultra-high molecular weight sodium polyglutamate to construct a sequential complexation system; subsequently adding potassium nitrate and citric acid aqueous solution; and finally, after filtration at 5 μm and heat treatment at 70℃, obtaining the organic liquid fertilizer. This fertilizer has a high proportion of 500-3000 Da oligosaccharides and a low reducing sugar equivalent, inhibiting storage precipitation and browning, and improving the retention rate of extractable oligosaccharides in the soil.