636 results about "Nitrogen atmosphere" patented technology

The invention belongs to the technical field of superfine tungsten powder, and particularly relates to superfine tungsten powder and a preparation method thereof.The preparation method includes the steps that an ammonium tungstate solution, hydrochloric acid and carbon black serve as raw materials to prepare a mixture of tungstic acid and a carbon precursor; calcining the tungstic acid and carbon precursor mixture in a nitrogen atmosphere to obtain a tungsten oxide and carbon mixture; a tungsten oxide and carbon mixture is calcined in an argon atmosphere, the argon atmosphere is kept for natural cooling, the superfine tungsten powder is obtained, the superfine tungsten powder is uniform in dispersion, complete in grain development, smooth in surface, free of pores and complex in morphology, the crystal structure of the superfine tungsten powder is a body-centered cube, the average particle size is smaller than or equal to 0.7 micrometer, and the specific surface area is smaller than or equal to 1.0 m < 2 > / g.

The invention belongs to the technical field of nickel electrode slurry preparation, discloses a preparation process of ultra-fine particle size roll-printed nickel electrode slurry for an ultra-high capacity MLCC, and aims to solve the problems that in the prior art, ultra-fine nickel powder is easy to oxidize, the cost of covering nickel nitride powder is high, a covering layer is easy to damage and agglomerate during dispersion, and the performance of the slurry is poor. The method comprises three steps of raw material pretreatment, synchronization of material dispersion and nitridation, post-treatment and nitrogen protection, wherein the pretreatment is used for removing impurities and preventing oxidation, dispersion and nitridation are carried out synergistically through a sand mill and an ultrahigh-pressure homogenizer in a graded regulation and control mode, the post-treatment comprises filtering, inspection and double-layer vacuum packaging, the raw materials are prepared according to a specific proportion, key parameters are precisely regulated and controlled, and finally the slurry is prepared. Roll printing adaptability and co-firing requirements are met, independent nitridation and reduction procedures are omitted, cost is reduced, slurry uniformity, dispersion stability and MLCC reliability are improved, and large-scale mass production can be achieved.

The invention belongs to the technical field of lithium battery materials, and particularly relates to a preparation method of high-purity lithium sulfide. Comprising the following steps: putting lithium hydroxide and pure water into a reaction kettle, replacing air in the reaction kettle with nitrogen, starting the reaction kettle, and stirring and heating; introducing quantitative hydrogen sulfide gas from the bottom of the reaction kettle, and circulating the gas in the reaction kettle between liquid in the reaction kettle and a gas space through a gas circulating pump; and after the temperature of the reaction liquid in the kettle is reduced to 20-30 DEG C, filtering in a nitrogen atmosphere, washing the residual solid with quantitative ammonia water, transferring the filtered solid into a drying box, and purging and drying with nitrogen until no water exists, thereby obtaining the high-purity lithium sulfide. In the solvent method, water is used for replacing an organic solvent for reaction, the problems of organic solvent separation and recovery, hazardous waste treatment and the like are avoided, the cost is reduced, and the method is environment-friendly.

The invention relates to a high-permeability ultralow-coercive-force soft magnetic stainless steel heat treatment process which comprises the following steps: in a nitrogen atmosphere, firstly heating a hot-rolled wire rod to 900-950 DEG C at a heating rate of 30-50 DEG C / h, preserving heat for 4-6 hours to obtain a fine grain structure of equiaxial recrystallization ferrite, then cooling to room temperature at a cooling rate of less than or equal to 15 DEG C / h to homogenize the ferrite structure, and finally cooling to room temperature at a cooling rate of less than or equal to 15 DEG C / h to obtain the high-permeability ultralow-coercive-force soft magnetic stainless steel. The soft magnetic stainless steel is obtained. The method has the advantages that the maximum magnetic conductivity of the soft magnetic stainless steel is improved, the coercive force of the soft magnetic stainless steel is reduced, and the plasticity index of the soft magnetic stainless steel is improved.

The invention relates to a preparation method of a high-activity transition metal phosphide catalyst, which comprises the following steps: taking basic nickel cobalt carbonate (NiCo-OH / NF) grown on foamed nickel in situ as a precursor, placing the precursor at the downstream of a tubular furnace, placing NaH2PO2 at the upstream of the tubular furnace, annealing in a nitrogen atmosphere at 350 DEG C for 2 hours, and naturally cooling to obtain NiCoP / NF; the preparation method comprises the following steps: soaking NiCoP / NF in a potassium salt solution of a boride, washing, and carrying out vacuum drying to obtain a boron-potassium modified catalyst precursor NiCoP-BK / NF; in a three-electrode system, electrodeposition is carried out in an electrolyte containing a Ni source, a Fe source and deionized water, and the high-activity transition metal phosphide-nickel iron hydroxide NiCoP-BK-coated NiFe-LDH / NF heterojunction composite catalyst is obtained. The activity and stability of the transition metal phosphide catalyst can be remarkably improved, and the preparation method is simple and low in cost.

The invention provides a method for additive forming of a high-performance Ti2AlNb three-period minimal curved surface lattice structure in a nitrogen atmosphere, and belongs to the technical field of additive manufacturing. Comprising the following steps: step 1) modeling an implicit function of a TPMS configuration: designing a CAD model of the TPMS configuration and exporting the CAD model as an STL file; 2, pretreatment of the Ti2AlNb lattice structure formed through L-PBF, wherein an STL file is subjected to slicing treatment, and technological parameters are set; 3, L-PBF forming of the Ti2AlNb lattice structure is conducted, specifically, in the nitrogen-argon mixed atmosphere, the Ti2AlNb lattice structure is formed through the L-PBF technology; and (4) the TPMS configuration Ti2AlNb lattice structure is subjected to surface treatment. According to the method, the Ti2AlNb lattice structure with the TPMS configuration is designed through implicit function modeling, the Ti2AlNb lattice structure with the TPMS configuration is formed through L-PBF in the nitrogen-argon reaction atmosphere, the problems that in traditional particle strengthening, reinforcements are distributed unevenly, and the solid solution strengthening effect is limited are solved, and good matching of the strength, plasticity and toughness of the lattice structure is achieved.

The invention relates to the technical field of medicine analysis and detection, and particularly discloses a method for detecting the content of protein in a 3D-MLA adjuvant, which comprises the following steps: (1) preparing a test solution: firstly dissolving the 3D-MLA adjuvant by using a hydrochloric acid solution, performing 300-600W ultrasonic treatment for 2-5min, centrifuging 10000-13000g for 4-7min, and taking supernate; adding a compound enzyme into the supernate for enzymolysis; then adding concentrated hydrochloric acid, uniformly mixing, hydrolyzing for 20 + / -2 hours in a nitrogen atmosphere at 105-115 DEG C, blow-drying, and dissolving with a hydrochloric acid solution to obtain a test sample stock solution; adding a derivatization reagent into the test sample stock solution, and carrying out derivatization treatment, extraction and dilution to obtain a test sample solution; and (2) high performance liquid chromatography determination. According to the detection method provided by the invention, the residual quantity of the host cell protein in the 3D-MLA can be rapidly and accurately determined, and the quality control of the 3D-MLA is realized.

The invention discloses a self-template synthesized linear biochar-based bimetallic material as well as a preparation method and application thereof, and belongs to the technical field of carbon materials. The method comprises the following steps: pretreating ganoderma lucidum residues, and pyrolyzing in a nitrogen atmosphere to prepare charcoal; and mixing the prepared biochar with cobalt nitrate and sodium molybdate to prepare CoMoO4 nanoparticles with in-situ growth of the biochar, and then washing and drying to obtain the BC-coated CoMoO4 linear biochar-based bimetallic material. Heterojunctions formed by binding sites of cobalt-molybdenum bimetal and biochar in the material form more defect sites, the synergistic effect of the metal and the micro-nano fibrous biochar is exerted, the degradation rate in the application of catalytic degradation of bisphenol A can reach 98.18% or above, a multiple reaction mechanism with sulfate free radicals is jointly shown, and the photocatalytic degradation of bisphenol A is realized. And the method has higher adaptability and effectiveness for complex pollutants.

The invention relates to a pickling process of a cold-rolled strip, and belongs to the technical field of metal surface treatment. The acid pickling process comprises the steps of surface pretreatment, sand blasting treatment, acid pickling, water washing, passivation and the like. In the surface pretreatment, an oil removing agent and a rust removing agent are used for removing oil stains and rust stains on the surface of the cold-rolled strip, and then deionized water is used for cleaning. 200-mesh brown aluminum oxide and high-purity nitrogen are used for blowing and removing solid impurities in the sand blasting treatment. And pickling is carried out by using a 180-220g / L hydrochloric acid solution at 60-80 DEG C for 3-10 minutes. And after washing, drying at 110 DEG C in a nitrogen atmosphere. In the passivation step, a sodium nitrite passivation solution with the mass fraction of 30-50% is sprayed under the nitrogen atmosphere, and a laser drying method is used for drying. In addition, the invention further provides a preparation method of the oil removal agent and the rust removal agent and specific parameters of sand blasting treatment, nitrogen purging, acid pickling, spraying and laser drying.

A perfluoroelastomer according to the present disclosure satisfies requirement 1 and has a crosslinkable group. Requirement 1: When the perfluoroelastomer is heated in a nitrogen atmosphere from a starting temperature of 40°C at a heating rate of 10°C / min from 40°C to 90°C, then held at 90°C for 120 minutes, then heated at a heating rate of 1°C / min from 90°C to 200°C, then held at 200°C for 240 minutes, then heated at a heating rate of 1°C / min from 200°C to 305°C, and held at 305°C for 720 minutes, the weight loss is 1.8 mass% or less.

The invention discloses a preparation method of a 6-alkyl aza-uracil compound, which comprises the following steps: in a nitrogen atmosphere solvent, irradiating a reaction mixture of an aza-uracil derivative and carboxylic acid active ester with visible light, adding a catalyst and stirring for reaction, and after the reaction is completed, performing column chromatography separation on the reaction mixed solution to obtain the 6-alkyl aza-uracil compound. The product 6-alkyl aza-uracil compound can be prepared. The synthesis method of the 6-alkyl aza-uracil compound provided by the invention does not need to use a photosensitizer and a metal catalyst, the reaction conditions are green and mild, and the operation is simple, convenient, rapid and efficient.

The invention relates to the field of inorganic powder preparation, and particularly discloses a preparation method and application of aluminum nitride powder. The preparation method of the aluminum nitride powder comprises the following steps: (1) by taking water as a dispersion medium, dispersing hydroxyl aluminum oxide and a carbohydrate into the dispersion medium, and then carrying out hydrothermal reaction to obtain a precursor; the precursor has a carbon-coated hydroxyl alumina core-shell structure; (2) calcining the precursor in a nitrogen-containing atmosphere to obtain aluminum nitride powder; wherein the volume equivalent diameter of the aluminum hydroxide is less than 0.82 mu m. By implementing the method, the aluminum nitride powder with high purity and excellent particle size distribution can be obtained.

The invention discloses an adsorbent for adsorbing V0Cs and a preparation method of the adsorbent. The adsorbent is prepared from the following raw materials in parts by weight: 50-80 parts of activated carbon, 20-40 parts of titanium dioxide, 10-30 parts of graphene, 10-20 parts of zeolite and 5-15 parts of a metal organic framework material. The preparation method comprises the following steps: S1, mixing the raw materials, adding deionized water, and stirring to form a uniform dispersion liquid; s2, performing ultrasonic treatment on the dispersion liquid, and drying to obtain a precursor; s3, calcining the precursor in a nitrogen atmosphere, and cooling to obtain the adsorbent. The preparation method has the beneficial effects that titanium dioxide realizes adsorption-degradation coupling through photocatalysis, so that the regeneration efficiency is improved; regular pore channels of zeolite realize molecular sieving, and selectivity is improved; the adsorption capacity is further optimized through the ultrahigh specific surface area and the adjustable aperture of the MOFs, dispersion of the nano-particles is promoted through ultrasonic treatment, and agglomeration is avoided; a stable composite interface is formed through high-temperature calcination, and the acting force between materials is enhanced; impurities are removed through acid activation, and the effective pore diameter is enlarged.

The invention relates to application and a preparation method of a nano nitride dispersion strengthened nickel-based superalloy, and belongs to the technical field of superalloy materials. The alloy comprises the following components in percentage by mass: 50.0 to 55.0 percent of Ni, 21.0 to 35.0 percent of Cr, 3.5 to 5.5 percent of Nb, 3.0 to 5.0 percent of Mo, 1.0 to 3.0 percent of Co, 0.3 to 1.1 percent of Al, 0.6 to 2.2 percent of Ti, 0.1 to 0.3 percent of Si, 0.01 to 1.0 percent of rare earth element (RE), 0.01 to 0.05 percent of C, 0.01 to 0.15 percent of N, 0.002 to 0.020 percent of B and the balance of Fe and impurities. By regulating and controlling the RE / N atomic ratio (1: 1-2: 3) and the Ti / Al ratio (1.5-2: 1) and combining selective laser melting (SLM) 3D printing and a multi-stage heat treatment process in a nitrogen-containing atmosphere, nanoscale rare earth nitride particles with the average size of 1-10 nm and the number density of 1 * 10 < 22 >-3 * 10 < 24 > m <-3 > are generated in an alloy matrix, and gradient distribution is formed at a gamma phase interface and a grain boundary (the surface density is 20-50% higher than that of the interior). The yield strength of the alloy at 750 DEG C reaches 1150-1260 MPa, the creep life is prolonged by 2-10 times compared with that of a traditional alloy, the use temperature upper limit is improved by 50-100 DEG C, and the alloy is suitable for high-temperature parts such as aero-engine turbine discs and combustion chambers and has high strength, long service life and oxidation resistance.

The invention relates to the technical field of lithium ions, in particular to a preparation method of a nitrogen and boron-doped silicon-carbon negative electrode material, which comprises the following steps: in a nitrogen atmosphere, putting porous carbon into a first reaction container, heating to a first reaction temperature, introducing nitrogen source gas, preserving heat for a first time, cooling to room temperature, and discharging to obtain a nitrogen-doped porous carbon material; and placing the obtained nitrogen-doped porous carbon material in a second reaction container, heating to a second reaction temperature in a nitrogen atmosphere, introducing a boron source gas and a silicon source gas, carrying out second heat preservation for a second time, heating the second reaction container to a third reaction temperature, introducing a carbon source gas, carrying out third heat preservation for a third time, cooling to room temperature, and discharging to obtain the nitrogen-doped porous carbon material. At the moment, boron-doped nano amorphous silicon particles are deposited in pores in the nitrogen-doped porous carbon material. The problems of structure pulverization and short cycle life caused by volume expansion of the silicon-based negative electrode material in the cycle process are solved.

The present invention discloses a Ni3InC 0.5 absorbing material and a preparation method thereof. (1) Ni(CH3COO)2·4H2O and In(CH3COO)2·6H2O are dispersed in N,N-dimethylformamide (DMF), and after magnetic stirring, liquid A is obtained; (2) terephthalic acid (PTA) and triethylamine (TEA) are dispersed in DMF, and after magnetic stirring, liquid B is obtained; (3) liquid B is poured into liquid A, and stirring is continued to obtain a Ni3InC 0.5 precursor solution; (4) the solution obtained in step (3) is filtered by a circulating water suction filter to obtain a gel-like sample; (5) the sample obtained in step (4) is calcined under a nitrogen atmosphere, and after natural cooling to room temperature, Ni3InC 0.5 is obtained. The present invention has the characteristics of simple process and low cost, and for the first time, this material is applied to the field of wave absorption.

The invention discloses a method for synthesizing 3, 3 '-difluorobenzene. The invention discloses a method for preparing 3, 3 ', 5, 5'-tetramethyl-4, 4 '-dihydroxybiphenyl and derivatives thereof, which comprises the following steps of: adding 1.0 mmol of 4-halogenated aryl phenol compound, 0.05 mmol of photocatalyst and a solvent into a reaction container in a nitrogen atmosphere, stirring until the materials are dissolved, adding 0.05 mmol of metal catalyst and 0.06 mmol of ligand which are prepared in advance, turning on a light source, stirring for 24 hours at room temperature, performing thin layer chromatography detection reaction, filtering, washing and drying to obtain the 3, 3', 5, 5 '-tetramethyl-4, 4'-dihydroxybiphenyl and derivatives thereof. And after the reaction is finished, filtering the reaction liquid, removing the solvent through rotary evaporation, and carrying out recrystallization or column chromatography by using a mixed solvent to obtain the target product 3, 3 ', 5, 5'-tetramethyl-4, 4 '-dihydroxybiphenyl and the derivative thereof. According to the method, the 4-halogenated aryl phenol compound is used as a raw material, the required compound is obtained in one step through'nickel + light 'catalysis, and waste and related pollution caused by the use of high-explosive gas or a reducing agent are not needed; and a recyclable photocatalyst is used, so that the method is more environment-friendly and has a good industrial application prospect.

The invention relates to the field of electrode materials, in particular to a preparation method of a silicon-carbon composite electrode material. The method comprises the following steps: carrying out crushing pretreatment on the silicon-containing agricultural residues, and mixing the silicon-containing agricultural residues with tetraethyl orthosilicate according to a mass ratio of (3-5): 1; raising the temperature to 200-800 DEG C at the speed of 5 DEG C / min in a nitrogen atmosphere, and performing constant-temperature pyrolysis for 30-60 minutes; in the pyrolysis process, the TEOS is decomposed to generate a SiO2 nano-template to regulate and control a pore structure, part of the SiO2 nano-template is reduced into SiO nano-particles, and a SiO (at) C core-shell structure material with microporous and mesoporous graded pores is formed in situ; the product, conductive carbon and polyvinylidene fluoride are prepared into slurry according to the ratio of (6-7): (1.5-3): (1-1.5), the slurry is coated on activated carbon cloth, and the activated carbon cloth is freeze-dried to prepare the electrode. According to the preparation method, through design of the green activating agent, synchronous silicon-based compounding, pore regulation and control and pyrolysis process optimization, the defects of the traditional technology in the aspects of environmental protection, pore regulation and control accuracy and functional compounding are effectively overcome, and the electrochemical performance of the agricultural residue-based electrode material is remarkably improved.

The invention belongs to the field of preparation of negative electrode materials, and provides a high-rate compacted negative electrode material and a preparation method thereof. The preparation method comprises the following steps: firstly, synthesizing ZIF-67 by taking cobalt nitrate and 2-methylimidazole as precursors, introducing tetraethoxysilane and tetrabutyl titanate through a sol-gel method for modification to obtain precursor powder, then heating the precursor in a tubular furnace by stages, and carrying out high-temperature carbonization in a mixed gas atmosphere to prepare an MOF derivative material; secondly, reacting the graphene oxide dispersion liquid with ascorbic acid in a nitrogen atmosphere to prepare partially reduced graphene oxide; mixing the graphene with a molybdenum disulfide dispersion liquid, and introducing dopamine, 3, 4-ethylenedioxythiophene, silver nitrate and the like to obtain a graphene-polymerized derivative; the preparation method comprises the following steps: uniformly mixing a base material, an MOF derivative material, carbon black, a graphene-polymerization derivative and the like to prepare negative electrode slurry, and carrying out gradient rolling and argon shield heat treatment to prepare the high-rate compacted negative electrode material.

The invention discloses a low-temperature catalytic degreasing and rapid densifying process of an MIM (metal injection molding) forming part, which comprises the following steps: (1) low-temperature catalytic degreasing: in a nitrogen atmosphere, catalytically decomposing a POM (polyoxymethylene) binder by a nitric acid / organic acid composite catalytic system at 80-120 DEG C; (2) surface activation treatment of the degreased green body: performing vacuum plasma cleaning to remove surface catalyst residues, and switching to H2 / N2 mixed gas to reduce residual impurities; and (3) gradient rapid sintering densification: gradient rapid sintering densification is adopted, three-stage gradient temperature control-pressure control is adopted, and the total sintering time is less than or equal to 3 hours. According to the method, low-temperature catalytic degreasing is adopted, the degreasing time is shortened, the surface of a degreased green body is activated, a traditional acid pickling or secondary degreasing step is avoided, gradient rapid sintering densification is achieved, and the density and performance of the material are improved.

The invention is suitable for the technical field of environmental governance, and particularly relates to a Fe / Nv-PCN piezoelectric material preparation method, which comprises: in-situ synthesis of a PCN material: roasting urea to obtain the PCN material; synthesis of an Nv-PCN material: in a nitrogen atmosphere, roasting the PCN material to obtain the Nv-PCN material; ferric chloride (FeCl3. 6H2O) and ferrous sulfate (Fe2SO4. 7H2O) are used as iron sources to prepare Fe3O4 nano particles; the preparation method comprises the following steps: loading Fe3O4 nanoparticles on an Nv-PCN material by an in-situ coprecipitation method, cooling to room temperature after the reaction is finished, taking out, washing with deionized water and absolute ethyl alcohol in sequence, and drying in a closed state to obtain the Fe / Nv-PCN composite material. Through the synergistic effect of iron doping and nitrogen vacancy, the piezoelectric property and the catalytic activity are remarkably improved, the electron transmission capacity and the redox activity of the material are enhanced through iron doping, the energy band structure of the material is optimized through nitrogen vacancy, and the piezoelectric effect and the free radical generation efficiency are improved; the material has dual functions of adsorption and catalytic oxidation, and can degrade pollution for a long time.

The invention discloses a high-refractive-index photo-thermal dual-curing optical adhesive and a preparation method thereof, and belongs to the technical field of high polymer materials, and the preparation method comprises the following steps: S1, preparation of high-refractive-index resin: placing biphenyl-4, 4 '-dithiol in a nitrogen atmosphere reaction kettle, adding a free radical thermal initiator, heating to 180-200 DEG C, reacting for 1-2 hours, and cooling to room temperature to obtain the high-refractive-index resin; dropwise adding alkenyl resin under the protection of nitrogen, stirring, reacting for 1-2 hours after dropwise adding, and cooling to room temperature to obtain high-refractive-index resin; s2, preparation of the optical adhesive: mixing the alicyclic epoxy resin, the high-refractive-index resin, the toughened resin, the liquid epoxy resin, the cationic photoinitiator and the cationic thermal initiator, and uniformly stirring in a dark place to obtain the adhesive. The problems that a traditional optical adhesive is poor in optical performance stability and unbalanced in mechanical and optical performance are solved. The application potential of preparing the high-performance optical adhesive is realized.

The present invention discloses a gradient-structured dispersion-strengthened high-entropy alloy nitride ceramic coating and a preparation method thereof. After sequentially depositing a Cr film and a FeCrAlTi film on a substrate by using a method combining multi-arc ion plating and magnetron sputtering, an FeCrAlTiSi-N film is obtained by sputtering an FeCrAlTiSi target in a nitrogen atmosphere. The coating obtained by the present invention has high film-substrate bonding strength, high hardness, excellent wear resistance and corrosion resistance to liquid lead-bismuth.

The application belongs to the field of organic synthesis, and particularly relates to a synthesis method of 2-(3,3-dimethylbutyl)pyridine. 2-vinylpyridine, brominated tertiary butane, a mixed solution of dimethyl ether and isopropyl ether as a reaction system solvent, nickel iodide as a nickel salt, bipyridine as a ligand, dicyclohexylmethylamine as a base in the system, 2,6-dimethyl-3,5-diethyl-1,4-dihydropyridine as a reducing agent, a photocatalyst 2,4,5,6-tetrakis(9 ‑ Carbazole) - m-phenylenedinitrile, under the condition of room temperature and nitrogen atmosphere, a reduction cross-coupling reaction is used to synthesize 2-(3,3-dimethylbutyl)pyridine. The application uses inexpensive nickel metal as a catalyst, constructs a cross-coupling reaction of carbon-carbon bond, and has the advantages of mild reaction condition, high economy and the like.

The invention belongs to the technical field of material corrosion protection, and particularly relates to a titanium-based corrosion inhibitor of a chloride molten salt medium and a preparation method and application of the titanium-based corrosion inhibitor. The corrosion inhibitor comprises an inner core made of sponge titanium particles; the outer layer is a mixed layer of magnesium oxide and amorphous carbon, and in the mixed layer, the magnesium oxide is dispersed in the amorphous carbon in the form of particles of 1-20 nm. The method comprises the following steps: S1, obtaining sponge titanium particles; s2, mixing a magnesium source, a carbon source and a dispersing agent, and preparing a solution with water; s3, adding sponge titanium particles into the solution, and uniformly stirring; s4, drying the dispersion liquid in a hot air atmosphere; and S5, calcining the dried mixed particles in a nitrogen atmosphere to obtain the titanium-based corrosion inhibitor of the chloride molten salt medium. The corrosion inhibitor can effectively remove impurities such as water and oxygen in the chlorate, and the corrosion resistance of a container material in the chlorate is improved.

The invention discloses a monatomic / nitrogen-doped carbon sphere material and a preparation method and application thereof, and relates to the technical field of electrochemical detection.The preparation method comprises the following steps that glucose and hexadecyl trimethyl ammonium bromide are added into deionized water to be subjected to a hydrothermal reaction, and carbon spheres are obtained; mixing, grinding and calcining the carbon spheres and urea to obtain nitrogen-doped carbon spheres; and adding a metal salt solution into the nitrogen-doped carbon sphere suspension, stirring, filtering, washing, drying, and finally calcining in a nitrogen atmosphere to obtain the monatomic / nitrogen-doped carbon sphere material. The invention also discloses the monatomic / nitrogen-doped carbon sphere material prepared by the method and application of the monatomic / nitrogen-doped carbon sphere material in electrochemical detection of organic pesticides. According to the nitrogen-doped carbon sphere, the single metal atoms are anchored on the vacancies on the nitrogen-doped carbon sphere, so that the sensitivity, the detection limit, the selectivity, the stability and the anti-interference capability of the nitrogen-doped carbon sphere when the nitrogen-doped carbon sphere is used for electrochemical detection of organic pesticides are remarkably optimized, and the nitrogen-doped carbon sphere has important practical application value.

This invention relates to a method for synthesizing N-H functionalized carbazole products based on Fe catalysis at room temperature and pressure. The method involves mixing α-aryl-α-diazo ester with carbazole or a carbazole derivative in an organic solvent, adding an Fe catalyst and additives, and reacting at room temperature and pressure to obtain the N-H functionalized carbazole product. This invention uses metallic Fe as a catalyst to react α-aryl-α-diazo ester to generate α-(N-carbazole)-α-aryl ester compounds under nitrogen atmosphere at room temperature and pressure. It also offers a wider range of selectable substrates and, compared to traditional synthesis methods, has many advantages such as high yield, simple conditions, low waste emissions, simple reaction equipment, and ease of industrial production.

Provided is a bonding material which is capable of forming a silver bonding layer that has good bondability with a material to be bonded, wherein the density (denseness) of the silver is good. The bonding material comprises an organic acid silver salt, an organic solvent, and silver particles. The organic acid silver salt has a weight loss rate (Mr1) of 5% or less when the temperature thereof is raised from 25°C to 200°C and a weight loss rate (Mr2) of 40% or more when the temperature thereof is raised from 200°C to 280°C as determined by simultaneous thermogravimetry-differential thermal analysis (TG-DTA) (in a nitrogen atmosphere at a nitrogen flow rate of 200 ml / min and a heating rate of 10° C / min). The organic solvent contains a compound represented by general formula (1) (in the formula, R1 represents a linear or branched alkyl group having 2 to 6 carbon atoms).　The silver particles include: first silver particles that have an average particle diameter (D50 diameter) of 0.15 μm or more and 0.4 μm or less; and at least one of second silver particles that have an average particle diameter (D50 diameter) of 0.6 μm or more and 1.0 μm or less and third silver particles that have an average particle diameter (D50 diameter) of 1.9 μm or more and 2.4 μm or less.

The application relates to the technical field of organic compound synthesis, and particularly provides a preparation method of a cyclopropane compound. gem The dichloro compound is used as raw material, a piezoelectric material, a metal reducing agent and an additive are added under a nitrogen atmosphere, a mechanical grinding method is used for reaction, and the reaction solution is subjected to post-treatment to obtain the cyclopropane compound. The method is simple in operation and mild in conditions, the raw material and reagent are cheap and easy to obtain and environment-friendly, a large amount of solvent or a high-cost catalyst does not need to be used, and the conversion can be successfully realized. In addition, the preparation method has good yield and functional group tolerance, is suitable for scale-up production, has a good industrial application prospect, and can be widely used in the fields of medical raw materials, intermediates and fine chemical synthesis.

Device for producing a solid cryogenic abrasive from water, characterized in that the cryo-tube and loading unit form a single unit, wherein one or more spray nozzle blocks, equipped with identical or different interchangeable spray nozzles, are arranged in the cone of the cryo-tube such that the water can be sprayed from below into a cold nitrogen atmosphere of the cryo-tube, and the amount of nitrogen required for ice formation can be introduced from nitrogen nozzles attached to the tube and the lid, and the frozen water droplets immediately fall from the cryo-tube into the loading unit for absorption into the transport gas stream, assisted by the gas pressure generated during freezing.