2899 results about "Reaction temperature" patented technology

The invention provides a self-repairing polyurethane film containing a disulfide bond and a DA bond and a preparation method thereof, and the preparation method comprises the following steps: (1) adding an organic solvent into a three-necked flask, then dissolving dihydric alcohol, diisocyanate, a disulfide bond monomer and a DA bond forming monomer in the organic solvent, then adding a catalyst, and mechanically stirring uniformly; (2) introducing nitrogen into the three-necked flask to evacuate air, setting a reaction temperature, and carrying out a reaction under mechanical stirring; (3) in a nitrogen environment, dropwise adding a monomer II forming a DA bond into the solution obtained after the reaction in the step (2), and after the dropwise addition of the monomer II forming the DA bond is completed, setting the reaction temperature and reacting for a period of time; and (4) pouring the solution obtained after the reaction in the step (3) into a polytetrafluoroethylene mold, and drying to obtain the self-repairing polyurethane film. The self-repairing polyurethane film prepared by the preparation method disclosed by the invention has relatively good mechanical properties, relatively good self-repairing performance under mild conditions and high self-repairing efficiency.

The invention relates to the field of white carbon black modifier production, and particularly discloses an activity monitoring and early warning method of a white carbon black modifier based on Internet of Things, which comprises the following steps: acquiring reaction temperature, catalyst dosage and equipment operation parameters in real time through an Internet of Things sensor, and constructing a parameter and efficiency mapping table to form a multi-dimensional process database; encoding the temperature, the stirring rate and the raw material ratio into chromosome genes by utilizing a genetic algorithm, and constructing a multi-target model by taking the bifunctional grafting rate as an optimization target and combining the equipment load rate and the energy consumption constraint; a high-adaptability parameter set is generated by adopting iterative optimization, and a three-level response mechanism of local fine tuning, population resetting and historical optimal parameter loading is realized in combination with a hierarchical early warning system. According to the method, the problems that the synthesis conditions of the bifunctional silane coupling agent cannot be accurately controlled and the continuous production data response is delayed in the traditional process are solved, and the activity dynamic optimization and green and efficient production of the white carbon black modifier are realized.

The invention relates to the technical field of catalysts, and discloses a preparation method and application of a copper-based metal-organic framework catalytic material.The preparation method comprises the following steps that S1, cuprous salt, N, N '-bis (5-aminonicotinyl) naphthalimide and a solvent are mixed, and a mixture is obtained; s2, heating the mixture to a reaction temperature, carrying out a constant-temperature reaction, and cooling to obtain a crystal; and S3, washing and drying the crystal to obtain the copper-based metal-organic framework catalytic material. According to the preparation method of the copper-based metal-organic framework catalytic material provided by the invention, N, N '-bis (5-aminonicotinyl) naphthalimide is used as an organic ligand to prepare the copper-based metal framework Cu-PTD with N / O co-coordination, and the copper-based metal framework Cu-PTD has relatively strong electrocatalytic carbon dioxide reduction and electron transfer capabilities; and the catalyst has relatively high selectivity on electrocatalytic carbon dioxide reduction products.

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 dynamic interactive prompt sequence control method for chemical production, and relates to the field of flow industrial processes. Based on a state transition rule of a Phase functional block, linear execution and conditional jump of sequential control steps in a polymerization reaction temperature step control scene are realized through SFC programming, interactive processing and SFC logic steps are bound, and an interactive dialog box is triggered in a unified manner through an operation guide window. And the main program and the subprogram realize abnormal state linkage through an FAILIDX mark, and automatically detect a fault clearing state when the abnormity is recovered. The interactive processing dynamically generates an option list, supports multi-language switching, verifies input values in real time, and provides historical suggested values. The method aims at solving the problems that in a traditional sequence control system, the coupling degree of interaction logic and a core control program is high, operation interfaces are not uniform, and the misoperation risk is high, transplanting of cross-control systems and cross-process packages is supported, and the secondary development cost is remarkably reduced.

The utility model relates to a reaction device capable of quickly heating, cooling and maintaining temperature. According to the reaction device, a three-way valve temperature control device consisting of a set of thermal medium circulator, a set of cold medium circulator, a control unit and two temperature control adjusting motor control three-way valve rotating devices is arranged on the reaction kettle, so that the temperature of the reaction kettle of the reaction device can be increased or decreased within half a minute (even shorter time); the problem that the reaction kettle cannot be rapidly heated and cooled in the reaction process is solved; for heat absorption and heat release experiments, the dynamic balance of the temperature can be maintained by setting a fixed reaction temperature; installation is simple, and operation is convenient; the problem of waste of water resources is solved; the temperature control range is wide, and when a water medium is used, the temperature control range is 1-95 DEG C; when a silicone oil medium is used, the temperature control range is-50 to 250 DEG C; the rotatable distillation head is mounted at the upper part of the reaction kettle and is directly rotated during use, so that the functions of condensation reflux and distillation extraction can be simultaneously realized.

The invention relates to a preparation method of a silver nanowire based on a phenolic compound and the silver nanowire, and the preparation method comprises the following steps: 1, respectively dissolving polyvinylpyrrolidone, small molecular phenolic acid, halide, a silver source and the phenolic compound in deionized water to obtain respective solutions; 2, sequentially adding a polyvinylpyrrolidone solution, a small molecular phenolic acid solution, a halide solution and a silver source solution, and stirring to obtain a reaction solution A; step 3, adding a phenolic compound solution into the reaction solution A to obtain a reaction system B, and stirring and reacting to obtain a mixed solution C containing silver nanowires; fourthly, the mixed solution C containing the silver nanowires is sequentially centrifuged and washed, and then the silver nanowires are prepared; the diameter of the silver nanowire is 20-150 nm, and the length of the silver nanowire is 5-100 [mu] m. Therefore, according to the design, water is adopted as a solvent to synthesize the silver nanowire, the reaction temperature is low, and the reaction speed is high.

The invention discloses a continuous synthesis and purification method of hexafluoropropylene oxide, which comprises the following steps: introducing hexafluoropropylene, oxygen and a fluorine-containing solvent into a supergravity reactor to carry out oxidation reaction at the reaction temperature of 100-200 DEG C under the reaction pressure of 1.0-2.5 Mpa for 10-120 seconds, and after the reaction is finished, overflowing and leading out reaction liquid to obtain the hexafluoropropylene oxide. And purifying to obtain the hexafluoropropylene oxide. According to the method, the problems of mass transfer and heat transfer can be effectively solved by using the supergravity reactor, the reaction selectivity is remarkably improved, meanwhile, the productivity is effectively improved, and the supergravity reactor is combined with extractive distillation treatment, so that the conversion rate of the hexafluoropropylene reaches 79% or above, the selectivity of the hexafluoropropylene oxide is 85% or above, and the purity of the hexafluoropropylene oxide after extractive distillation reaches 99%. The invention further discloses a device used in the continuous synthesis and purification method, and cyclic utilization of hexafluoropropylene and the fluorine-containing solvent can be achieved.

The preparation method comprises the following steps: mixing 20-40 parts by mass of substituted hydroxymethyl glycoluril, 45-85 parts by mass of mercaptocarboxylic acid and 0.5-3 parts by mass of an acidic catalyst, stirring and reacting for 1-10 hours at the temperature of 50-150 DEG C under the pressure condition of-0.01 to-0.1 MPa, adding 300-800 parts by mass of an organic solvent for diluting after the reaction is finished, washing and purifying with deionized water, and collecting an organic layer, thereby obtaining the mercaptan curing agent. Concentrating and drying to obtain the mercaptan curing agent. According to the thiol curing agent, the rigid glycoluril group is introduced, so that the rigidity of a cured product structure is improved, and the mechanical property, the adhesive property, the heat resistance and the damp-heat aging resistance of a cured product are improved; four tertiary amine groups in the substituted glycoluril have a certain self-promotion effect on a thiol curing epoxy reaction, and the curing reaction temperature is reduced under the condition that an accelerant is not added; the glycoluril-containing thiol epoxy resin curing agent disclosed by the invention has good application value and development prospect.

The invention relates to the technical field of material preparation, and discloses a polyamide elastomer and a preparation method and application thereof, and the preparation method of the polyamide elastomer comprises the following steps: mixing raw materials, and carrying out amidation reaction to obtain an amide compound; then adding a catalyst B, and carrying out polyesterification reaction to obtain a polyamide elastomer; the raw materials comprise binary acid, diamine, polyether glycol, a catalyst A and water, the reaction temperature of the amidation reaction is 150-180 DEG C, and the addition amount of the water is 20-40% of the total mass of the binary acid, the diamine and the polyether glycol. The polyamide elastomer which is relatively regular in structure and excellent in comprehensive performance can be prepared, the reaction efficiency can be effectively improved, and the preparation method is suitable for industrial large-scale production.

The invention relates to the field of polymerization reactions. A synthetic latex polymerization reaction temperature optimization control method comprises the steps that temperature detection data of a reaction kettle in synthetic latex polymerization reaction are obtained, and the temperature detection data comprise polymerization reaction area real-time distribution temperature, reaction kettle temperature distribution data and heat transfer medium flow data; obtaining a thermal stress index value according to the real-time distribution temperature of the polymerization reaction zone, and generating a reaction zone parameter compensation amount according to the thermal stress index value; and obtaining the uniformity index of the temperature field of the reaction kettle according to the temperature distribution data of the reaction kettle. Through real-time acquisition and coupling analysis of multi-source data such as temperature deviation of a polymerization reaction zone, uniformity of a temperature field in a kettle, flow fluctuation of a heat transfer medium and the like, a multi-dimensional coupling matrix of thermal stress, uniformity and flow fluctuation is constructed, and the limitation of traditional single-parameter control is broken through; and comprehensive evaluation of the reaction heat state, the stirring effect and the heat exchange stability is realized.

The invention discloses a compound containing a urea structure as well as a preparation method and application of the compound in a color developing agent, and relates to the technical field of color developing agents. The compound containing the urea structure is a # imgabs0 # structure as shown in a formula 1. The compound containing the urea structure is synthesized through multiple steps of Suzuki reaction, bromination reaction and substitution reaction. The compound is used as an electron donor to be applied to a thermosensitive color development system and forms a color development composition with a phenolic compound and an acidic material, and the activation temperature is as low as 60-120 DEG C. The ureido structure stabilizes a reaction intermediate through a hydrogen bond network, enhances the electron transfer efficiency, and significantly improves the color developing sensitivity; the aryl / heteroaryl substituent optimizes the color contrast through the conjugation effect, and meanwhile, the synergistic effect of the hot-melt filler ensures the stability of the system. Compared with a traditional color developing agent, the color developing agent has the advantages of low-temperature activation, high color developing intensity and excellent weather resistance, is suitable for the fields of thermal printing, anti-counterfeiting materials and the like, and overcomes the defects of high reaction temperature and insufficient stability in the prior art.

The present application relates to the technical field of polyimides and relates to a preparation method for a high-performance polyimide and an application thereof, aiming to solve the problems in the prior art such as numerous side reactions and severe impact on transparency caused by an excessively high imidization reaction temperature during the use of a high-temperature thermal imidization method for the preparation of polyimides. The preparation method comprises: (1) preparing a polyamic acid solution; (2) adding a chemical catalyst and a polyamic acid solution to partially complete an imidization reaction; (3) adding an end group auxiliary agent, performing coating with the solution, heating, and maintaining the heat to complete the imidization reaction; and (4) carrying out high-temperature treatment to obtain a high-performance polyimide. The present application can significantly reduce numerous side reactions present in a traditional imidization reaction, eliminate an adverse effect of high-temperature imidization on the optical performance, greatly improve the mechanical properties, heat resistance, optical performance, etc. of a material, and also achieve both high heat resistance and high transparency.

The invention belongs to the field of preparation of medical intermediates, and particularly relates to a preparation method of an On-DNA sulfinic acid structure compound. The method for preparing the On-DNA sulfinic acid structure compound comprises a step of oxidizing On-DNA thiol (phenol) into the On-DNA sulfinic acid structure compound under alkaline and heating or illumination conditions, a solvent used in the reaction step is a mixed solution of water, dimethyl sulfoxide, N, N-dimethylformamide, acetonitrile, ethanol or tetrahydrofuran, the reaction temperature is not more than 80 DEG C, and the reaction time is not more than 2 hours. And the illumination wavelength ranges from 365 nanometers to 535 nanometers. The On-DNA sulfinic acid structure compound obtained in the invention can be directly used for constructing a structure compound with a sulfonyl group, the reaction condition is mild and convenient, a new method and a new idea are provided for construction of a DNA coding compound library, and the On-DNA sulfinic acid structure compound has a very good application prospect in lead drug development.

The invention discloses a reaction device based on dichlorobenzonitrile synthesis and a use method thereof, and relates to the field of reaction devices.According to the technical scheme, the reaction device comprises a reaction tank and a cover located at the top end of the reaction tank, a heating interlayer is arranged on the reaction tank, and a spiral conveying pipe surrounding a reaction cavity in the middle of the reaction tank is arranged in the heating interlayer; the heating medium is conveyed through the spiral conveying pipe, and the gap between the heating interlayer and the spiral conveying pipe is filled with the heat preservation material, so that the heating medium is conveyed around the reaction cavity in the heating interlayer through the spiral conveying pipe, and the spirally distributed conveying pipe can enable the heating medium to uniformly act on the outer wall of the reaction cavity; heat loss is reduced through the heat preservation material between the heating interlayer and the spiral conveying pipe, accurate control and uniform distribution of the reaction temperature are achieved, side reactions caused by local overheating are avoided, and therefore generation of polychlorinated impurities is reduced, and the purity of the dichlorobenzonitrile product is improved.

The invention discloses a preparation method of hydrogenated benvitimod and analogues thereof, and belongs to the technical field of organic synthesis. The method comprises the following steps: S1, mixing a compound I and palladium carbon in a solvent to obtain slurry; s2, under the protection of nitrogen, preheating the silicon carbide microchannel reactor to 20-70 DEG C, and then introducing hydrogen and the slurry in the step S1; the reaction temperature is 20-70 DEG C, the reaction pressure is 1-10 kg, and the retention time of the slurry is 1-20 min; and S3, carrying out solid-liquid separation, concentration, recrystallization and drying on the reaction liquid in the step S2 to obtain a compound II. The method adopts continuous flow production and is suitable for industrial production; the reaction speed is high, and the residence time does not exceed 20 min and is much shorter than overnight time in the prior art; the reaction yield is high and can reach 95% or above, and the yield of part of compounds can reach 99% or above; the catalyst dosage is small, and the reaction cost is greatly reduced.

The invention relates to the technical field of smelting, in particular to a preparation method of direct reduction iron. The preparation method of the direct reduced iron comprises the following steps: by taking high-temperature and high-pressure hydrogen-rich synthesis gas generated by gasifying a biomass raw material as reducing gas, reducing pellets containing medium-low-grade iron ores to obtain the direct reduced iron, the high-temperature and high-pressure hydrogen-rich synthesis gas comprises H2 and CO; when the molar fraction of H2 is 50% < = XH2lt; when the content is 65% and the molar fraction of CO is 30%-45%, the reduction reaction temperature is 900-950 DEG C; when the molar fraction of H2 is 65% < = XH2lt; when the molar fraction of CO is 90% and the molar fraction of CO is 5%-30%, the reduction reaction temperature is 850-900 DEG C; when the molar fraction XH2 of H2 is greater than or equal to 90%, the reduction reaction temperature is 800-850 DEG C; the method can realize direct reduction of hydrogen groups of medium-low-grade iron ores, and is low in energy consumption and less in carbon emission.

The invention provides a preparation method and a preparation device of a silicon carbide epitaxial wafer. The preparation method comprises the following steps: providing a substrate, and placing the substrate in an epitaxial reaction cavity; the substrate is heated, the distance between the substrate and a heating heat source is controlled to be H mm, and the reaction temperature in the epitaxial reaction cavity is T DEG C; introducing carrier gas, a growth source and a doping source, and preparing an epitaxial layer on the surface of the substrate to obtain a silicon carbide epitaxial wafer; wherein the distance H mm and the reaction temperature T DEG C meet the condition that (T-1500) / H is larger than or equal to 5.5 and smaller than or equal to 7. By controlling the distance between the substrate and a heating heat source, the airflow and the temperature field on the surface of the substrate are adjusted, the temperature difference between the center and the edge of the wafer is reduced, and the triangular defects on the surface of the wafer are reduced; meanwhile, the distance between the substrate and the heating heat source is matched with the temperature in the epitaxial reaction cavity, the growth rate of the epitaxial layer can be ensured, triangular defects are reduced, meanwhile, step defects are avoided, and therefore the overall quality of the epitaxial wafer is improved.

The invention discloses a production method for biosynthesis of rebaudioside M. Reb A / Reb D has poor solubility at a low temperature, and the reaction efficiency can be obviously accelerated when the Reb A / Reb D is catalytically produced in a high-temperature environment, so that the whole reaction system is carried out in the high-temperature environment, and the production efficiency can be improved. Under the reaction temperature environment of 70 DEG C, the wild type first glycosyltransferase or / and the wild type second glycosyltransferase are / is basically inactivated, and the catalytic enzyme combination cannot meet the requirement of industrial biosynthesis of rebaudioside M. The wild-type catalytic enzyme is mutated, so that the wild-type catalytic enzyme can keep high catalytic activity at 70 DEG C. Therefore, the production cost of the rebaudioside M produced by the production method disclosed by the invention is obviously lower than that of the prior art, and the method is suitable for industrial popularization.

The present invention relates to a process for producing molybdenum dioxide dichloride, which is a very efficient process that does not use hazardous chlorine gas and high reaction temperatures and enables the production of molybdenum dioxide dichloride in high yield without solvent.

The invention discloses a method for preparing polyol ester by carrying out hydrogen esterification reaction on long-chain olefin and polyol, which comprises the following steps of: by taking the long-chain olefin and the polyol as reactants, introducing carbon monoxide to control the pressure to be 1.0-8.0 Mpa and the reaction temperature to be 60-150 DEG C under the action of a composite catalyst consisting of a palladium compound, a phosphine ligand and organic acid and an organic solvent; and preparing to obtain the polyol ester for lubrication. Compared with the existing polyol ester synthesis method, the method has the advantages of mild reaction conditions, wide raw material applicability, high reaction activity and the like.

This invention relates to a method for using a low-content ruthenium-based catalyst modified with nitrogen and oxygen ligands in the hydrochlorination of acetylene. The invention utilizes 2-pyridine carboxylate as a ligand, commercial activated carbon as a support, trace amounts of ruthenium as the main active component, and water as a solvent. An improved synthesis procedure yields a low-content ruthenium-based catalyst with ruthenium ions coordinated by a modifier and commercial activated carbon as a support, significantly improving catalyst performance while reducing ruthenium content. This catalyst exhibits high activity and vinyl chloride selectivity in the fixed-bed hydrochlorination of acetylene to vinyl chloride, and its low cost makes it highly valuable for industrial applications. The ruthenium loading is 0.1%, and the reaction gas space velocity is 170 h⁻¹. ‑1 V (C2H2) / V (HCl) With a ratio of 1:1.05 and a reaction temperature of 180℃, the acetylene conversion rate can reach 84.3%, the vinyl chloride selectivity is greater than 99%, and the activity remains basically unchanged within 10 hours.

The invention provides a preparation method of high-viscosity water-soluble melamine formaldehyde resin, which comprises the following steps: adding a first part of formaldehyde solution and water into a reaction kettle, fully and uniformly stirring, adjusting the pH value of the system in the reaction kettle, and controlling the reaction temperature in the reaction kettle at 25-30 DEG C; adding polyvinyl alcohol into the reaction kettle, raising the temperature in the reaction kettle to 48-52 DEG C, and keeping the temperature for 10-30 minutes; slowly raising the temperature in the reaction kettle to 90 DEG C, adding melamine and an environment-friendly accelerant into the reaction kettle, stirring and preserving heat for 8-12 minutes, and adding a melamine prepolymer modifier into the reaction kettle; adding a first part of formaldehyde solution into the reaction kettle, controlling the reaction temperature in the reaction kettle to be 92-95 DEG C, adding a second part of formaldehyde solution into the reaction kettle after reacting for 10 minutes, continuously stirring, and controlling the reaction temperature in the reaction kettle to be quickly reduced to 58-62 DEG C; and adding urea into the reaction kettle, naturally cooling to room temperature, and discharging glue. The melamino-formaldehyde resin prepared by the invention has the advantages of high viscosity, good water solubility, low free formaldehyde and longer storage life.

The application provides a reverse water gas shift catalyst, a preparation method and application thereof, and the reverse water gas shift catalyst prepared by the preparation method has excellent catalytic activity and high CO selectivity in a reverse water gas shift reaction. The preparation method comprises the following steps: contacting a precipitating salt solution with a precipitant aqueous solution and performing co-precipitation, and simultaneously controlling the reaction temperature to be 40-80 DEG C and the pH to be 6-8; optionally performing aging after the co-precipitation is completed; filtering the obtained precipitate to obtain a filter cake, washing the filter cake, then drying the filter cake, and calcining the filter cake at 300-500 DEG C to obtain the reverse water gas shift catalyst; wherein the precipitating salt solution is a mixed aqueous solution of a soluble salt of divalent metal ions and a soluble salt of trivalent metal ions, the divalent metal ions are selected from divalent ions of Mg and / or Zn, and the trivalent metal ions are selected from trivalent ions of Al, In and / or Ga.

The invention discloses a preparation method of superfine calcium citrate suitable for liquid calcium, which comprises the following steps: S1, taking citric acid, citrate and calcium carbonate to react in water to obtain calcium citrate; the reaction temperature ranges from 80 DEG C to 90 DEG C, and the reaction time ranges from 10 min to 20 min; s2, performing vacuum freeze drying and primary crushing on the calcium citrate to obtain coarse powder; s3, absolute ethyl alcohol is added into the coarse powder and mixed evenly, low-temperature superfine grinding is carried out, the adding amount of the absolute ethyl alcohol is 8%-10% of the mass of the coarse powder, and the low-temperature superfine grinding temperature is 0-5 DEG C. On the basis of a normal calcium citrate preparation method, the calcium citrate is crushed and dispersed at a low temperature by using vacuum freeze drying, stabilizer adding and ice crystallization superfine grinding technologies, so that the structural stability of the calcium citrate is improved, and the problems of layering, thickening, solidification and the like are avoided when the calcium citrate is applied to liquid calcium.

The invention relates to the technical field of new material application, and discloses a magnetic bead material for enriching a sulfydryl peptide fragment and a preparation method thereof.The magnetic bead material prepared from micron carboxyl magnetic beads, dodecane dicarboxylic acid dihydrazide and SPSP has a long chemical reaction connecting arm, so that a reaction group has the better freedom degree, the reaction with sulfydryl is better facilitated, and the magnetic bead material can be used for enriching the sulfydryl peptide fragment. The enrichment efficiency is relatively high. When the magnetic bead material is prepared, micron carboxyl magnetic beads and dodecane dicarboxylic acid dihydrazide are based on hydrazine group and carboxyl condensation, the condensation reaction is more selective and more stable, the reaction is carried out under a milder condition, the reaction product is stable, and the reaction efficiency is higher at a lower reaction temperature. Dodecane dicarboxylic acid dihydrazide and SPSP are based on a reaction of N-succinimide and hydrazine, N-succinimide has high specificity to amino-containing molecules, side reactions are reduced, the reaction is generally carried out at room temperature, strong acid and alkali conditions are not needed, and protection of other sensitive groups is facilitated.

Subject of the invention are a modified biochar and methods for its production. In the method, biochar powder is modified in a chemical reaction with maleic anhydride, wherein the reaction is carried out at a temperature of at least 150°C, wherein the modified biochar is not subjected to carbonization after the reaction. Subject of the invention are also composite materials, shaped objects and construction parts, which comprise the modified biochar.

The invention belongs to the technical field of metal preparation, and particularly relates to a Fe-Al-Nb alloy and a preparation method thereof. Comprising the following steps: mixing ferric oxide, niobium pentoxide powder and a metal diluent, performing ball milling, and pressing into a green body; and the blank is put into a reaction kettle, then an ignition agent is added, protective gas is inflated, a self-propagating reaction is conducted at the temperature of 260-300 DEG C, and the Fe-Al-Nb alloy is obtained. The Fe-Al-Nb alloy is prepared through the self-propagating reaction, the reaction temperature is reduced, the thermal stress during forming is improved, the temperature of the self-propagating reaction is only 260-300 DEG C, meanwhile, the self-propagating reaction mode is adopted, the alloy is rapidly cooled after reacting, the fine grain strengthening effect is promoted to be more obvious, a microstructure of a Fe3Al matrix phase and a C14 Laves reinforced phase is formed, and the Fe-Al-Nb alloy is obtained. And the distribution of a reinforced phase is more uniform, and the wear resistance of the material is improved.

The invention belongs to the technical field of metal powder materials, and particularly relates to a preparation and surface modification method of silver-coated copper powder. Comprising the following steps that copper powder activated through a mixed acid solution and a dispersing agent are dissolved in ethyl alcohol, and copper powder turbid liquid is obtained; dropwise adding the silver complexing solution into the copper powder turbid liquid under the condition of water bath heating for reaction to obtain silver-coated copper powder turbid liquid; then, a reducing agent solution is dropwise added into the silver-coated copper powder turbid liquid, silver ions in the solution are further reduced, solid-liquid separation, washing and drying are conducted, and primary silver-coated copper powder is obtained; and finally, the silver-coated copper powder is subjected to surface modification, and the dispersity of the silver-coated copper powder is improved. The preparation method of the silver-coated copper powder provided by the invention is simple in process, and in the chemical oxidation reduction process, the prepared silver-coated copper powder is compact in silver coating, complete in coating, low in resistivity and good in oxidation resistance by regulating and controlling the concentration of silver ions and the complexing agent, the reaction temperature, the type of the dispersing agent, the dripping rate and the type of the surface modifier.

The invention discloses a preparation method of a high-capacity magnesium-based composite material based on MOF structure modification, and belongs to the technical field of hydrogen storage materials, the preparation method comprises the following steps: (1) preparing an M-MOF guest material; (2) modifying an aperture structure of the M-MOF guest material; and (3) preparing the MgH2 (at) S-M-MOF compound by a wet impregnation nano confinement method. Compared with a pure MgH2 hydrogen storage material, the MgH2 (at) S-M-MOF compound magnesium-based hydrogen storage material prepared by the nano confinement method has the advantages that the hydrogen absorption and desorption reaction temperature is obviously reduced, and the dynamics is greatly improved; compared with a traditional nano confinement hydrogen storage material preparation process, the preparation method has the advantages that the comprehensive hydrogen storage performance of a compound is enhanced by modifying a pore structure and introducing catalytic elements, the operability is high, the effective loading rate is high, the preparation period is short, and the yield is high; the required raw materials are cheap and easy to obtain, and the preparation process is low in cost, high in safety and suitable for industrial production and popularization.