9954 results about "Aqueous solution" patented technology

The application provides a process method for preparing (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl) phosphonic acid, and particularly relates to the technical field of organic synthesis. The process method is that, under alkaline conditions, a halogenated phosphonate compound is added into a 3,6-dimethoxy-9H-carbazole solution to perform a reaction, hydrochloric acid aqueous solution is added after the reaction to perform acidolysis degreasing, and finally (2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl) phosphonic acid is obtained through extraction, reflux adsorption and beating purification. The process method uses 3,6-dimethoxy-9H-carbazole as a starting material, realizes the synthesis of the target product through one-pot reaction, has mild reaction conditions, uses non-toxic raw materials which are easy to obtain, has simple synthesis process, is convenient to operate, and has high separation yield.

The invention discloses ultra-high performance concrete and a preparation method thereof. The ultra-high performance concrete comprises the following components in percentage by mass: 15%-25% of cement, 3%-6% of nano SiO2, 30%-35% of fly ash or steel slag powder, 35%-40% of recycled aggregate, 1%-4% of fiber, 0.5% of a microbial remediation agent and 1%-3% of nano TiO2. The preparation method comprises the following steps: S1, pretreating the recycled aggregate; and S2, packaging the microbial remediation agent: mixing the bacillus pasteurii spores with calcium lactate, and wrapping the mixture in calcium phosphate microspheres. S3, step-by-step stirring; S3.1, dry mixing: uniformly stirring the cement, the fly ash, the nano SiO2, the nano TiO2 and the recycled aggregate; s3.2, wet mixing is carried out, water solution fibers containing the polycarboxylic acid water reducing agent are added, uniform stirring is carried out, and the water-binder ratio of the water solution containing the polycarboxylic acid water reducing agent is 0.18; s3.3, final mixing: adding the packaged microbial remediation agent, and uniformly stirring; and S4, directional curing: performing steam curing at 80 DEG C for 48 hours, performing ultraviolet irradiation, and performing constant-temperature and constant-humidity curing for 7 days. The ultra-high performance concrete has the effects of low cost, low carbon emission, multi-function integration and repeatable crack self-repairing.

The invention relates to a crown ether covalent organic framework material as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving a crown ether monomer and an amino monomer in an o-dichlorobenzene solvent, adding a catalyst acetic acid aqueous solution, and uniformly dispersing to form a reaction solution; the method comprises the following steps: freezing a reaction solution through a liquid nitrogen bath, vacuumizing, filling nitrogen, carrying out a heating reaction, and carrying out post-treatment operations such as washing and drying on a reaction product, so as to obtain the crown ether covalent organic framework material BADT-DB18C6-COF. The crown ether covalent organic framework material is formed by condensation of a crown ether aldehyde monomer and an amino monomer, the crown ether monomer is 4, 4 ', 4' ', 4 '''-(6, 7, 9, 10, 17, 18, 20, 21-octahydrodibenzo [B, K] [1, 4, 7, 10, 13, 16] hexaoxacyclo octadecene-2, 3, 13, 14-tetrayl) tetrabenzaldehyde, and the crown ether monomer is 4, 4 ', 4' ', 4'''-(6, 7, 9, 10, 17, 18, 20, 21-octahydrodibenzo [B, K] [1, 4, 7, 10, 13, 16] hexaoxacyclo octadecene-2, 3, 13, 14-tetrayl) tetrabenzaldehyde. The amino monomer is 4 ', 5'-bis (4-aminophenyl)-[1, 1 ': 2', 1 ''-terphenyl]-4, 4''-diamine. The crown ether covalent organic framework material BADT-DB18C6-COF prepared by the invention is mainly used as an adsorbent, is used for adsorbing and recovering uranium, thorium and americium ions from a solution, shows good adsorption capacity on radionuclides U-238, Th-232 and Am-243, and is particularly suitable for the field of spent fuel post-treatment in the nuclear industry.

The invention relates to the technical field of organic chemical synthesis, in particular to a preparation method of 3, 4 '-diaminodiphenyl ether.The preparation method comprises the steps that S1, under inert gas and in a first solvent, m-dinitrobenzene and p-acetamidophenol are subjected to a heating reaction under the condition of a weak base catalyst, and 3-nitro-4-acetamido diphenyl ether is prepared; s2, in a second solvent, the 3-nitro-4-acetamido diphenyl ether is subjected to a hydrogenation reduction reaction, and 3-amino-4-acetamido diphenyl ether is prepared; and S3, dissolving the 3-amino-4-acetaminodiphenyl ether in an alcohol solvent system, adding an aqueous solution of alkali, controlling the reaction temperature, carrying out a hydrolysis reaction, and after the reaction is finished, carrying out post-treatment to obtain the 3, 4 '-diaminodiphenyl ether. The preparation method provided by the invention has the advantages of easily available raw materials, low price, good selectivity and high product yield, and is more suitable for industrial production by comprehensively considering economical efficiency and safety.

The invention discloses a production method of distiller's grain fermentation liquid fertilizer specially applied to roxburgh rose. The distiller's grain fermentation liquid fertilizer is prepared bythe step of evenly mixing 50 to 80 parts of distiller's grain fermentation extracting solution, 0.5 to 1 part of microelement, 5 to 10 parts of seaweed meal, 5 to 10 parts of natural active organism,2 to 5 parts of potassium bicarbonate, 2 to 5 parts of natural active organism and 2 to 5 parts of natural surface active agent. A preparation method of the distiller's grain fermentation extracting solution comprises the steps: evenly stirring 50 to 80 parts of distiller's grain, 50 to 150 parts of rice washing water, 1 to 2 parts of EM microflora fermentation liquid and 0.5 to 1 part of sugar, performing composting fermentation at the room temperature to obtain a distiller's grain fermentation material, stirring and extracting through a sodium carbonate water solution, filtering and performing evaporation and condensation on obtained filtrate until the density is 1.1 to 1.2 to obtain distiller's grain fermentation extracting solution. The distiller's grain fermentation liquid fertilizerdisclosed by the invention has a good use effect, meanwhile can effectively prevent pest and disease damage to the roxburgh rose and is high-efficiency environment-friendly liquid fertilizer.

The invention discloses a method for preparing nano barium titanate based on sol-gel synergistic hydrothermal reaction, which comprises the following steps: (1) dissolving barium acetate in an acetic acid aqueous solution to obtain a barium source solution; weighing tetrabutyl titanate according to the molar ratio of barium to titanium being greater than 1.25, and dissolving the tetrabutyl titanate in alcohol to obtain a titanium source solution; (2) uniformly mixing the barium source solution and the titanium source solution, preserving heat at 20-80 DEG C to obtain gel, drying and grinding to obtain white powder of the barium titanate precursor: (3) preparing a 2-4mol / L inorganic strong alkali aqueous solution, adding the white powder and a dispersing agent into the inorganic strong alkali aqueous solution, and fully stirring to obtain a barium titanate precursor suspension; and (4) transferring the barium titanate precursor suspension into a reaction kettle for hydrothermal reaction, and after the reaction is completed, washing, drying and grinding to obtain the nano barium titanate powder. The preparation method is low in cost, and the prepared nano barium titanate powder is uniform in distribution, spherical or sphere-like in morphology, small in particle size, 80-150nm in average particle size and good in particle crystallinity.

The invention belongs to the technical field of pharmaceutical chemical processes, and particularly relates to a preparation method of a penem antibiotic intermediate 4-BMA, which comprises the following steps: adding Zn powder, chlorosilane, aliphatic tertiary amine, zinc salt and 4-AA in a formula (I) into THF (tetrahydrofuran), uniformly stirring, dropwise adding a THF solution of alpha-haloamide with an induction group in a formula (II) for reaction, filtering the reaction solution, removing the zinc powder, and drying to obtain the penem antibiotic intermediate 4-BMA. Extracting the filtrate to obtain a THF phase, washing with an aqueous solution of potassium oxalate, and recovering THF to obtain a formula (III); and carrying out oxidative hydrolysis, sulfur dioxide quenching, sulfur dioxide acid regulation crystallization and recrystallization on the formula (III) to obtain the intermediate 4-BMA. According to the preparation method disclosed by the invention, a zinc salt is used as a catalyst during preparation of the formula (III), potassium oxalate is used for removing residual Zn (II) in a THF phase, SO2 is used for quenching hydrogen peroxide and acid regulation and crystallization of 4-BMA, the oxygenolysis problem of 4-BMA is solved, and the preparation method has the characteristics of greenness, safety and high efficiency, is strong in product competitive advantage and is suitable for industrial production.

The invention discloses a preparation method of an acid-resistant polyquaternary ammonium membrane based on a Porxitch interfacial polymerization reaction. The preparation method comprises the following steps: dissolving an amine monomer in a water-phase solvent to form a water-phase solution; dissolving a bromomethyl monomer in an organic phase solvent to form an organic phase solution; after the base membrane is soaked in the water phase solution for a period of time, the water phase solution is removed, and the water phase solution remaining on the surface of the base membrane is removed; coating the organic phase solution on the surface of a base membrane, and carrying out interfacial polymerization reaction for 1-15 minutes at the high temperature of 50-90 DEG C, so as to prepare a polyquaternary ammonium membrane on the base membrane; and washing the surface of the polyquaternary ammonium membrane with an organic solvent to remove residual reactants, and then carrying out heat treatment in a drying oven to obtain the acid-resistant polyquaternary ammonium membrane.

The application discloses a method for selectively preparing furan amine or tetrahydrofuran amine from furan aldehyde substances, which comprises the following steps: in an aqueous solution with the volume percentage concentration of ammonia water being greater than 70%, furan aldehyde substances are subjected to a reductive amination reaction in the presence of H2 and under the action of a catalyst to prepare furan amine; and in an aqueous solution with the volume percentage concentration of ammonia water being less than 20%, furan aldehyde substances are subjected to a reductive amination reaction in the presence of H2 and under the action of a catalyst to prepare tetrahydrofuran amine. The method can realize the selectivity of products by changing the addition amount of ammonia water in the aqueous solution, and is simple, easy to control, and suitable for industrial production and market promotion and application.

The invention provides a preparation method of prismatic titanium diboride powder, and belongs to the technical field of titanium diboride powder. The preparation method comprises the steps of titanium source preparation, boron source preparation, material mixing, cold isostatic pressing and carbon thermal reduction reaction. The step of preparing the titanium source comprises the following steps: heating TiO2 powder body liquid, raising the temperature to 52-55 DEG C, adding a tetrabutyl titanate solution, uniformly stirring, adding an ammonia water solution to adjust the pH value to 7.0, and carrying out heat preservation stirring for 2.7-3.2 hours to obtain the titanium source; the step of preparing the boron source comprises the following steps: adding B4C powder into absolute ethyl alcohol, carrying out ultrasonic dispersion, then adding a mixed solution, controlling the adding rate of the mixed solution to be 0.8-1.2 g / min, heating to 34-37 DEG C, and carrying out heat preservation and stirring for 3.8-4.2 hours to obtain the boron source; the titanium diboride powder obtained through the method is in a prism shape and is uniform in particle, high in density and purity and poor in high-temperature oxidation resistance.

This invention discloses a method for preparing a CuZnAlGa-based layered double hydroxide (TLH)-derived catalyst for methanol production from carbon dioxide-rich syngas. Using Cu, Zn, Al, and Ga metal salts as precursors, Na₂CO₃ and NaOH as precipitants, and a mixed alcohol-water solution as an auxiliary solvent, co-precipitation is performed under controlled temperature and pH to obtain a LDH-like catalyst precursor. After high-temperature calcination and in-situ reduction in a hydrogen atmosphere, a layered framework structure of Cu nanoparticles immobilized by oxides is obtained. The LDH-like structure provides lattice confinement, preventing Cu particle aggregation, and the interaction between Cu and the oxides enhances the catalyst surface's adsorption capacity for CO and CO₂, thereby improving the activity and stability of methanol production from carbon dioxide-rich syngas.

A marine urea aqueous solution preparation device, and a preparation method therefor. The marine urea aqueous solution preparation device comprises a water bath barrel (1), a preparation barrel (2) fixed to an inner wall of the bottom of the water bath barrel (1) by means of a support leg, and a gap between the water bath barrel (1) and the preparation barrel (2) is used to contain fresh water to heat the preparation barrel (2). A top cover (6) is fixed to the top of the preparation barrel (2) by means of multiple bolts, and multiple heaters (11) are fixed to an inner wall of the water bath barrel (1). The urea aqueous solution is stirred by means of a stirring rod (3), which can sequentially drive a swinging structure and an intermittent structure, so that urea particles are intermittently sprinkled into the preparation barrel (2) in small batches.

The invention provides weather-resistant anti-freezing road concrete and a preparation method thereof, and belongs to the technical field of concrete. The concrete comprises the following components: sulphoaluminate cement, Portland cement, silica fume, fly ash, modified granite gravel coarse aggregate, medium sand fine aggregate, silica fume blended fiber, silica fume blended polyacrylonitrile fiber, a composite air entraining agent, a functional modifier, a composite antifreeze agent, pre-absorbent zeolite powder and the like. The preparation method comprises the following steps: modifying granite macadam with Al (H2PO4) 3, SiO2 and methoxypolyethylene glycol triethoxysilane, and modifying with a lithium silicate aqueous solution to obtain the modified granite macadam coarse aggregate. The composite air entraining agent comprises a JRY-Q air entraining agent and sodium alpha-olefin sulfonate. The functional modifier is prepared from gas phase method spherical nano silicon dioxide and nano alpha-Al2O3. The composite antifreeze agent comprises ethylene glycol butyl ether acetate and modified calcium carbonate. The modified calcium carbonate is obtained by sequentially modifying nano calcium carbonate with calcium chloride, a KH-550 silane coupling agent and stearic acid.

The invention is suitable for the technical field of flame retardance of high polymer materials, and provides a core-shell structure graphite phase carbon nitride derivative and a preparation method thereof.The derivative is prepared by the steps that a precursor containing phosphorus and boron elements is mixed with melamine, and phosphorus / boron co-doped graphite phase carbon nitride is prepared through a high-temperature thermal polymerization reaction; and then assembling the phytic acid copper on the surface of the graphite-phase carbon nitride in an in-situ growth manner by adopting an aqueous solution self-assembly method to construct a derivative with a core-shell structure. The invention provides the graphite phase carbon nitride derivative with the core-shell structure, which is green, environment-friendly, efficient and flame-retardant and simple and convenient in process, and the preparation method of the graphite phase carbon nitride derivative, and the graphite phase carbon nitride derivative has wide application prospect and industrialization value.

The invention discloses a bionic lignin-based saline-alkali soil improvement material and a preparation method thereof, and belongs to the technical field of high polymer materials and soil improvement. According to the saline-alkali soil improving material, lignin or a derivative thereof serves as a framework, glutenin charge distribution and a dynamic disulfide bond sodium ion response function are simulated, and the sequence and the proportion of chain segments of sulfonic acid groups and quaternary ammonium salt groups are accurately regulated and controlled through step-by-step activation and alternate copolymerization in an aqueous solution polymerization reaction system; positive and negative charges form more uniform sequence distribution, so that the amphipathy of the lignin compound is realized; then, sulfydryl is introduced through click chemistry, linear regulation and control of material viscosity and water solubility are achieved through the chain transfer characteristic of multi-sulfydryl functional groups, and the requirements of different saline-alkali soil application scenes are met. The limitation that a traditional lignin product is single in function is broken through, efficient utilization of lignin is achieved, and the intelligent saline-alkali soil improvement material integrating high stability and pH and Na < + > multi-environment response is developed.

A free-flowing solid activator for a geopolymer mortar or concrete comprises or consists of an alkali(ne) metal carbonate surface treated with a sub-stoichiometric amount of alkali(ne) metal hydroxide. In one embodiment a method for producing an activated fly ash comprises: a) spraying an aqueous alkali(ne) metal silicate onto the surface of a solid particulate fly ash; b) drying the spray-treated product of step a); c) optionally grinding the dried product of step b); and optionally, repeating the spray treatment process for the product of step b) or step c) by returning the product of step b) or step c) to step a).

The invention discloses injectable hydrogel for photo-thermal adjuvant therapy of periodontitis and a preparation method, and belongs to the technical field of high polymer material preparation, the preparation method comprises the following steps: reacting MXene dispersion liquid with epigallocatechin gallate and MgSO4; then sequentially carrying out ultrasonic treatment, centrifugation, washing and freeze-drying to obtain a multifunctional nanosheet MP-Mg; adding the multifunctional nanosheet MP-Mg into an oxidized gellan gum aqueous solution, and carrying out a mixed reaction to obtain a solution A; mixing the quaternary ammonium salt chitosan aqueous solution and the carboxymethyl chitosan aqueous solution in equal volume, and reacting to obtain a solution B; and mixing the solution A and the solution B in equal volume for reaction. The hydrogel prepared by the preparation method disclosed by the invention has injectability, photo-thermal responsiveness, biological membrane penetrability, synergistic antibacterial property and long-acting anti-inflammatory property, and an innovative and practical photo-thermal adjuvant therapy platform is provided for clinical treatment of periodontitis.

The invention discloses a preparation method of an ultra-pure hydroxylamine aqueous solution, and relates to the field of organic chemistry and chemical industry production. The method comprises the following steps: reacting electronic-grade hydroxylamine salt with organic alkali in a proper solvent to generate hydroxylamine, then separating and removing salt and unreacted hydroxylamine in a reaction solution through a mercaptopyridine ion exchange modified membrane, and finally concentrating the solution into 50wt% ultra-high-purity hydroxylamine aqueous solution by adopting reduced pressure evaporation or multi-effect evaporation. The process has the characteristics of high efficiency, environmental protection, simplicity and easiness in operation, effectively improves the purity, yield and separation efficiency of hydroxylamine, and meets the strict requirements of electronic grade hydroxylamine on purity and metal ion content.

The invention belongs to the technical field of liquid chromatography-mass spectrometry detection pretreatment, and particularly relates to a pretreatment method for liquid chromatography-tandem mass spectrometry analysis of pesticide and veterinary drug residues in serum, which comprises the following steps: (S1) carrying out heating reaction on Sc (III) salt, Cu (II) salt and 1H-pyrazole-4-formic acid (H2PyC) in a polar aprotic solvent, and cooling to obtain a green crystal, namely MOF-919; the chemical formula of the MOF-919 is [Sc < 3 > (mu3-O) (OH) < 3 >] [Cu3 (mu3-O) (mu-PyC) < 3 > (H2O) < 6 >] < 2 >; (S2) mixing the serum sample with an acetonitrile solution containing formic acid, carrying out ultrasonic treatment, vortex oscillation and centrifugation, taking supernate, and diluting the supernate with an aqueous solution containing formic acid to obtain a to-be-purified solution; and (S3) adding MOF-919 into the to-be-purified liquid, mixing, performing ultrasonic treatment, performing vortex oscillation, centrifuging, and taking supernate, thereby completing the pretreatment of the to-be-purified liquid. According to the method, the MOF-919 is used for adsorbing chemical pollutant residues in serum, especially phospholipids, so that the purpose of removing the chemical pollutant residues in blood is achieved. The method is simple and convenient to operate, small in organic solvent consumption and good in purification effect, and can be widely applied to residue analysis of chemical pollutants in serum.

The invention relates to a detection method for determining isotope abundance of a 15N or 18O labeled nitrate sample by using an organic mass spectrum. The detection method comprises the following steps: (1) dissolving the 15N or 18O labeled nitrate sample in a methanol aqueous solution; (2) taking the supernatant, filtering with a filter membrane, and diluting with a methanol aqueous solution to obtain a solution to be detected; and (3) detecting the solution to be detected by using a high-resolution liquid chromatograph-mass spectrometer, selecting a mass spectrum in a peak appearance time window, recording relative mass spectrum signal intensities with mass-to-charge ratios of 61.988 and 62.985, and calculating to obtain the 15N isotope abundance. Or recording the relative mass spectrum signal intensities with the mass-to-charge ratios of 61.988, 63.993, 65.997 and 68.001, and calculating to obtain the abundance of the < 18 > O isotope. Compared with the prior art, the method has the advantages that the sample pretreatment time is greatly shortened, the economic cost is low, and the test result is accurate.

The invention discloses application of sodium tetraphenylborate in carbon sourcing of landfill leachate and a carbon sourcing method and device. According to the invention, sodium tetraphenylborate is used as an ammonia nitrogen removing agent and is added into the percolate sewage of the organic garbage, so that the carbon nitrogen ratio of supernatant liquid is increased, and then the supernatant liquid is used as a carbon source. The basic principle that sodium tetraphenylborate is subjected to a precipitation reaction with ammonia ions in an aqueous solution is utilized, then standing separation is selected according to precipitation properties, and discharged water can be stored as a carbon source or directly added into a water treatment process in the form of the carbon source. The precipitate is collected and dehydrated, the precipitate can be recycled as a precipitant after being heated and recovered by alkali liquor, and the released concentrated ammonia gas is collected and can be used for industrial production. The method has the advantages of high reaction efficiency, low interference degree, high controllability of carbon-nitrogen ratio, recyclable main reagents, low theoretical operation cost, obvious removal effect on chroma of sewage, and high industrial value of discharged carbon-sourced water.

The invention relates to the technical field of nano ceramic materials, and particularly discloses a self-cleaning antibacterial functional ceramic which is prepared by the following steps: S1, mixing titanium dioxide powder, a composite binder, functional gel, a plasticizer and a solvent, and performing ball milling for 18-20 hours to obtain composite slurry; s2, putting the composite slurry into a mold, and carrying out mold pressing and drying to obtain a green body; and S3, placing the green body in a high-temperature sintering furnace, carrying out high-temperature sintering, and cooling to room temperature to obtain the self-cleaning antibacterial functional ceramic, according to the invention, functional gel and a composite binder are added, and the functional gel is obtained by mixing and reacting composite modified nano zinc oxide, a cross-linking agent and an alumina precursor; the composite binder is prepared by mixing a polyvinyl alcohol aqueous solution, an aluminum dihydrogen phosphate aqueous solution, silica sol and a tackifying component, and through the synergistic effect of the substances, the mechanical property and the antibacterial property of the functional ceramic are improved.

The invention relates to a textured KCu7S4 thermoelectric material and a preparation method thereof, and the method comprises the steps: sequentially adding a prepared KOH aqueous solution, CuCl2. 2H2O and Na2S. 9H2O into a high-pressure kettle, and fully stirring for dissolving; dropwise adding an N2H4.H2O aqueous solution into the mixed solution, fully stirring, sealing, transferring to a microwave chemical synthesis instrument, heating, keeping stirring, and reacting at a target temperature and self-generated pressure to generate a KCu7S4 nanowire preferentially growing along a [001] crystal orientation; and after the reaction is finished and natural cooling is carried out, a product is collected through centrifugation, full cleaning and vacuum drying are carried out, and then the KCu7S4 thermoelectric material with [001] preferred orientation in the direction perpendicular to the pressure direction is obtained through spark plasma sintering. According to the method, a surfactant and an organic solvent are not used, and macro, rapid, efficient and controllable preparation of the KCu7S4 nanowire is realized through a low-temperature, low-cost and low-energy-consumption microwave-assisted hydrothermal process.

A polymer of formula I. and uses of the polymer for the removal of removing per- and polyfluoroalkyl substances from aqueous solutions.

The invention discloses a low-temperature-resistant polyacrylamide flocculant suitable for a low-temperature water body and a preparation method of the low-temperature-resistant polyacrylamide flocculant. The flocculant is prepared from the following raw materials in parts by weight: 60 to 85 parts of acrylamide (AM), 15 to 40 parts of low-temperature-resistant functional monomer 2-acrylamide-2-methylpropanesulfonic acid (AMPS), 0.5 to 5 parts of hydrophobic modified monomer, 0.1 to 1.0 part of molecular chain regulator, 0.01 to 0.1 part of initiator, 120 to 200 parts of deionized water and 1 to 5 parts of post-added antifreezing agent. The product is prepared by an aqueous solution polymerization method. According to the invention, by introducing the rigid sulfonic monomer and the functional monomer with large steric hindrance and compounding the specific antifreezing agent, the extensibility and diffusion performance of a polymer molecular chain in low-temperature (less than or equal to 10 DEG C) water are remarkably improved, so that large and dense flocs can be quickly formed under the low-temperature condition, and an excellent flocculating settling effect is kept.

The invention relates to the field of pharmaceutical analytical chemistry, in particular to a method for determining tandospirone and salt intermediates thereof, high performance liquid chromatography is adopted, and chromatographic conditions include that a chromatographic column with octadecylsilane chemically bonded silica as a filler is adopted, and gradient elution is performed by a mobile phase A and a mobile phase B; wherein the mobile phase A consists of a first water phase and acetonitrile; the mobile phase B is composed of a second water phase and acetonitrile; the first water phase is a water solution containing monopotassium phosphate and sodium hexanesulfonate, and the pH value of the first water phase is 3.0-3.8; the second water phase is an aqueous solution containing monopotassium phosphate and sodium hexanesulfonate, and the pH value of the second water phase is 1.8-2.6. The testing method disclosed by the invention has good specificity, accuracy and repeatability, and can be used for monitoring the quality of the tandospirone raw material medicine.

S-Beta-hydroxybutyric acid compositions for oral delivery are effective in rapidly raising blood ketone levels without causing acute acidosis or gastrointestinal (GI) distress when consumed in sufficiently dilute form and / or as a gel or suspension. By limiting added beta-hydroxybutyrate salts containing alkali or alkaline earth metal ions, beta-hydroxybutyric acid solutions, gels, or suspensions can deliver exogenous ketone bodies without significantly altering electrolyte balance. Although aqueous beta-hydroxybutyric acid solutions are moderately acidic with a pH of about 3.5 to 4, when diluted with sufficient water, the water acts as a pseudo buffering agent that offsets otherwise harsh acidic effects when consumed orally. Gels and suspensions can also ameliorate acidic effects by partially encapsulating the beta-hydroxybutyric acid. Beta-hydroxybutyric acid can be pure S-beta-hydroxybutyric acid or a non-racemic mixture enriched with S-beta-hydroxybutyric acid relative to R-beta-hydroxybutyric acid.

The invention relates to the technical field of oilfield chemistry, in particular to an aminoethanesulfonic acid type surfactant and a preparation method and application thereof.The preparation method of the aminoethanesulfonic acid type surfactant comprises the steps that firstly, fatty amine is dissolved in a first solvent, a sodium chloroethanesulfonate aqueous solution is added, and N-long-chain alkyl-2-sodium aminoethanesulfonate is obtained through a reaction; and 2, dissolving a required amount of N-long-chain alkyl-2-sodium aminoethanesulfonate in a second solvent, adding a required amount of methyl acrylate, and reacting to obtain the aminoethanesulfonic acid type surfactant. The aminoethanesulfonic acid type surfactant disclosed by the invention contains long-chain alkyl, amino, ester groups and sulfonic acid groups, so that the aminoethanesulfonic acid type surfactant has good surface activity and can meet the development requirements of oil and gas fields. The microemulsion cleanup additive prepared from the aminoethanesulfonic acid type surfactant can effectively reduce the surface tension and the interfacial tension of an aqueous solution, and the preparation method is easy and convenient to operate, mild in condition and suitable for industrial production.

The invention discloses uniform-particle-size silk fibroin microspheres and a preparation method and application thereof.The preparation method comprises the following steps that a regenerated silk fibroin solution is taken and subjected to trypsin digestion to obtain modified silk fibroin sediment, and the modified silk fibroin sediment is dissolved in an aqueous solution of a beta-folding inhibitor to obtain a silk fibroin solution serving as a dispersed phase; emulsifying through an external pressure type membrane emulsifier to obtain an emulsion containing the silk fibroin emulsion droplets; adding a cross-linking agent into the emulsion to carry out cross-linking reaction, and then adding a crystallization inducer to induce crystallization to obtain primary silk fibroin microspheres; and performing vacuum freeze drying to obtain the silk fibroin microspheres. Silk fibroin is subjected to enzyme digestion modification, silk fibroin fragments with high beta-folding content are reserved, and high structural stability is achieved; the crystallinity of the microspheres is improved by adopting a membrane emulsification mode and combining a multiple crystallization induction method, and the silk fibroin microspheres with uniform particle size and smooth surfaces are obtained.

To provide a method for fixing carbon dioxide by which bubbles of carbon dioxide introduced into a solution can be made fine without increasing energy consumption.SOLUTION: A carbon dioxide fixation method comprising a precipitation step of introducing a gas containing carbon dioxide into a carbon dioxide fixation solution in which calcium ions are eluted to generate bubbles of the gas containing carbon dioxide in the carbon dioxide fixation solution, thereby reacting the calcium ions eluted in the carbon dioxide fixation solution with carbon dioxide to precipitate calcium carbonate, wherein the carbon dioxide fixation solution is an aqueous solution in which calcium ions are eluted in an aqueous solution of methylparaben.SELECTED DRAWING: Figure 1