443results about How to "Inhibit aggregation" patented technology

The invention relates to a composite multi-effect scale and corrosion inhibitor and a preparation method thereof, and belongs to the technical field of water treatment agents.The composite multi-effect scale and corrosion inhibitor is prepared from carboxylic acid monomers, sulfonate monomers, organophosphorus compounds, modified chitosan, modified nanometer titania, oxidation type initiators, reduction type initiators, azole derivatives and the like, the modified chitosan is formed by coating the surface of chitosan with cerium chloride; the modified nano titanium dioxide is formed by coating the surface of nano titanium dioxide with sodium polyaspartate. The composite multi-effect scale and corrosion inhibitor is prepared in a mode of compounding while synthesizing, the scale inhibition effect is excellent, the comprehensive descaling capacity can reach 97% or above, and the composite multi-effect scale and corrosion inhibitor can be used for a high-pH, high-alkalinity, high-temperature and high-hardness circulating cooling water system under the high-concentration-multiple operation condition; the method is suitable for circulating cooling water treatment requirements under harsh conditions in industries such as chemical industry, smelting and light industry.

The invention discloses a radial flow field bipolar plate and a fuel cell stack structure, and belongs to the technical field of fuel cells, the radial flow field bipolar plate comprises a bipolar plate body, two sides of the bipolar plate body are respectively provided with an anode side groove and a cathode side groove, the middle part of the bipolar plate body is provided with a cathode air inlet channel, and one side of the cathode air inlet channel is connected with a connecting cylinder; a plurality of anode rib plates which are distributed in a multi-stage arc shape are arranged on the bottom surface of the anode side groove, and two anode air holes are formed in the side wall of the anode side groove; a plurality of cathode rib columns distributed in a multistage radial mode are arranged on the bottom face of the cathode side groove, cathode air inlet holes are formed in the side wall of the connecting cylinder, and cathode air outlet holes are formed in the side wall of the cathode side groove in a penetrating mode. The structure is simple and compact, stacking is convenient, the gas flowing state is effectively improved, more uniform gas distribution is realized, uniform reaction in the whole electric pile is ensured, and the efficiency and performance of the electric pile are improved; and the pressure drop during gas flowing can be reduced, so that the operation of the galvanic pile is more energy-saving and efficient.

The invention discloses a hydrogel scaffold with multiple physical gradients. The hydrogel scaffold is prepared from the following synthetic raw materials: thermo-sensitive polyisocyanide polypeptide, silk nanofibers rich in beta lamellar structures and a conductive nanomaterial. The conductive nano material dispersion liquid and the BSNF solution are uniformly mixed according to a ratio of 1: 4; at 4 DEG C, adding a BSNF-loaded conductive nano material mixture into a PIC aqueous solution, uniformly mixing, adding into a square tank with an electrode, and applying a direct-current electric field to the hydrogel; after the electric field is removed, the temperature is raised to 25 DEG C, PIC is induced to form gel, and the conductive hydrogel stent with multiple physical gradients is obtained. The hydrogel contains multiple physical gradient structures such as rigidity, conductivity and morphology. The multi-gradient hydrogel with different patterns can be constructed by regulating and controlling the shape, the position and the electric field applying time of the electrode; the preparation method disclosed by the invention is simple, convenient to operate, simple in equipment and process requirements, low in cost and capable of realizing large-scale industrial production.

The invention belongs to the technical field of smoke dust purification, and particularly relates to a purification workshop with multiple purification functions, the purification workshop comprises a telescopic arm, the telescopic arm is connected with a purification box, and the bottom of the purification box is communicated with a dust collection cover; a smoke dust purification mechanism is arranged in the purification box, a metal filter screen cylinder is installed in the purification box, an electromagnetic suction strip is arranged on the cylinder wall of the metal filter screen cylinder, a dust filter screen cylinder is inserted into the metal filter screen cylinder in a sealed mode, the cylinder wall of the metal filter screen cylinder and the cylinder wall of the dust filter screen cylinder are installed in a non-contact mode, and a filter element is arranged in the dust filter screen cylinder. The top of the purification box communicates with a dust suction pipe, and a pipe opening of the dust suction pipe is aligned with a barrel opening of the dust filter screen barrel; according to the smoke dust collecting and purifying device, smoke dust generated by welding can be collected and purified in a short-distance and concentrated mode, the situation that the collected smoke dust flows in a pipeline for a too long time, and consequently the pipeline is blocked is avoided, and the phenomenon that energy is wasted due to the fact that the smoke dust generated by welding in a welding workshop is dispersed can be reduced.

The invention discloses a process for treating sucralose wastewater through gradient wet oxidation, which belongs to the field of wastewater treatment, and comprises the following steps: mixing sucralose wastewater with first air, conveying the mixture to a first wet oxidation unit, and carrying out wet oxidation reaction under a medium temperature condition; mixing the treated wastewater with second air, conveying the mixture to a second wet oxidation unit, and carrying out wet oxidation reaction at high temperature; part of the treated wastewater is returned to the first wet oxidation unit, part of the treated wastewater is returned to the second wet oxidation unit, and part of the treated wastewater is discharged. The temperature range is accurately regulated and controlled according to the properties of the wastewater and the pollutants, the pollutants are degraded in stages, the pollutants in the sewage can be efficiently treated in an energy-saving manner, and meanwhile, the problem that the sucralose production wastewater is polymerized and coked when an air source wet oxidation method is used for treating the sucralose production wastewater is solved.

The invention provides a method for improving the emulsibility of soybean milk, which comprises the following steps: placing soybean milk in a composite electromagnetic field which comprises an alternating electric field and a rotating magnetic field which are superposed; wherein the excitation voltage of the applied alternating electric field is 400-700 V, the frequency of the applied alternating electric field is 400-500 Hz, the magnetic field intensity of the applied rotating magnetic field is 8-12 mT, the frequency of the applied rotating magnetic field is 5-10 Hz, and the direction of the alternating electric field is perpendicular to the direction of the rotating magnetic field, so that the composite electromagnetic field is formed through superposition. An induced electric field and an induced current formed in the soybean milk by the applied alternating electric field can change the polarity environment of the soybean milk and inhibit protein in the soybean milk from being condensed into macromolecular agglomerates, and the applied rotating magnetic field can enable the protein to be uniformly dispersed in the soybean milk, so that the emulsibility of the soybean milk is improved; the soybean milk treated by the method is finer and softer in taste, and the quality is improved.

The invention discloses a cooling anti-radiation coating and a preparation method thereof. The cooling anti-radiation coating comprises a surface coating, a middle coating and a bottom coating, the surface coating comprises the following components in percentage by weight: 40-60% of polyethylene, 1-5% of carbon nanotubes, 1-5% of graphene oxide, 10-15% of a dispersant, 5-8% of polyethylene glycol, 3-8% of nano barium oxide and 3-10% of nano boron nitride. The intermediate coating comprises the following components in percentage by weight: 50%-70% of polyurethane, 20%-30% of a silane coupling agent and 5%-10% of aluminum oxide; the bottom coating comprises the following components in percentage by weight: 70%-80% of resin, 7%-9% of talcum powder, 2%-4% of aluminum oxide and 3%-10% of hydroxyethyl cellulose. The cooling anti-radiation coating formed by the synergistic cooperation of the components has high electromagnetic shielding performance and long service life.

The invention discloses an ozone catalyst and a preparation method and application thereof, Ni (NO3) 26H2O and Al (NO3) 29H2O are used as raw materials, and NiAl-LDH is prepared through a coprecipitation method; the preparation method comprises the following steps: preparing NiAl-LDH, reacting NiAl-LDH, AgNO3 and a Na2HPO4 solution to prepare Ag3PO4, and finally compounding NiAl-LDH and Ag3PO4 to prepare the ozone catalyst Ag3PO4 / NiAl-LDH composite material. The Ag3PO4 / NiAl-LDH composite material is used as an ozone catalyst to be applied to algae removal through combination of catalytic ozonation and a quorum sensing inhibitor, so that cell walls and internal structures of algae are more efficiently destroyed, and the algae removal effect is improved.

The invention relates to the technical field of electrochemical sensing, in particular to an MXene-coated MB / PtNPs electrochemical sensor and a preparation method thereof and a carbendazim detection method, MXene is used as a carrier, PtNPs is embedded between layers and on the surface of MXene through reduction reaction, then electroactive molecules MB are introduced through electrostatic interaction, an MXene-coated MB / PtNPs composite material is formed, and the MXene-coated MB / PtNPs electrochemical sensor is prepared. And then modifying a glassy carbon electrode by using the MXene coated MB / PtNPs composite material to prepare the MXene coated MB / PtNPs electrochemical sensor. The compound is used as a ratio electrochemical sensor for detecting carbendazim, the linear range of the compound to carbendazim is 10-30000 ng / mL, the detection limit is 3.3 ng / mL, the detection speed is high, the sensitivity is high, the linear range is wide, the precision is high, the detection limit is low, meanwhile, the anti-interference performance and repeatability are good, and the compound has potential application prospects in the field of agricultural product quality detection.

The invention relates to the technical field of catalysts, in particular to a catalyst for hydrodechlorination synthesis of 2, 3-dichloropyridine, a preparation method of the catalyst and a synthesis method of the 2, 3-dichloropyridine. The catalyst comprises a carrier, an active component loaded on the carrier and a coating layer located outside the carrier, the active component is Pd; and the coating layer is made of a nitrogen-doped carbon material. According to the present invention, the nitrogen-doped carbon material (CN) is adopted to coat the Al2O3-loaded Pd catalyst (PdM / Al2O3, and M is adopted as the auxiliary agent), the acid-base property of the catalyst surface is adjusted, and the electronic structure of Pd can be changed through the interaction of CN and Pd so as to improve the catalytic performance of the catalyst; meanwhile, CN can inhibit poisoning, loss and aggregation of the Pd active component, so that the stability and recycling performance of the catalyst are improved. In addition, due to the addition of the auxiliary agent, the dispersity of Pd is improved, and the activity of the catalyst is further improved.

The invention discloses a preparation method of a self-supporting carbon nanofiber loaded high-spinning Fe monatomic catalyst and application of the self-supporting carbon nanofiber loaded high-spinning Fe monatomic catalyst in a flexible zinc air battery, and the self-supporting carbon nanofiber loaded high-spinning Fe monatomic catalyst (Fe-N4 / NGC-C) is prepared by using an electrostatic spinning technology in combination with a high-temperature pyrolysis strategy; the carbon nanofiber has the advantages of high length-width ratio, large specific surface area, strong stability and the like, can realize uniform distribution of metal Fe monatomic, and inhibits aggregation of electrocatalytic active sites in the carbonization process. According to the preparation method, the atom utilization rate and the conductivity can be improved, and low load and high catalytic performance are realized.

A preparation method of a magnetic metal nanoparticle-loaded nitrogen-doped wood carbon aerogel wave-absorbing material comprises the following steps: step 1, delignification is performed on cut natural wood, and then freeze drying is performed to obtain delignified wood aerogel; 2, the delignification wood aerogel and a metal adenine solution are subjected to a reaction in a reaction kettle, then freeze drying is conducted, and wood aerogel loaded with a metal adenine complex is obtained; 3, the wood aerogel loaded with the metal adenine complex is subjected to high-temperature carbonization treatment in inert gas, and the nitrogen-doped wood carbon aerogel wave-absorbing material loaded with the magnetic metal nanoparticles is obtained. According to the method, natural wood with a directional multilevel pore channel structure is used as a raw material, and a metal-organic complex grows in situ in a pore channel of the wood through solvothermal reaction. The invention aims to realize uniform dispersion and loading of magnetic nanoparticles in a wood carbon-based material so as to solve the problems of non-uniform structure, complex processing procedures and the like in the preparation process of the wave-absorbing material.

The present invention discloses a mixing device for glass production, and relates to the technical field of glass production. The mixing device of the present invention is designed with an air inlet pipe so that external air can be introduced into the mixing chamber during the mixing process, thereby effectively improving the mixing uniformity of the raw materials. Compared with the single mechanical stirring method of traditional equipment, the introduction of air enables the raw materials to be better dispersed during the mixing process, avoiding the stratification or aggregation of different materials due to density differences; the collection shell in the equipment is connected to the mixing chamber, and cooperates with the negative pressure environment to realize continuous material discharge and screening functions. By setting up multiple discharge ports, the timely discharge of smaller particles during the mixing process is ensured, avoiding the interference of large particles on the mixing process.

The invention discloses a stable oncolytic adenovirus composition, which contains adenovirus or recombinant oncolytic adenovirus modified based on the adenovirus, and also contains a nonionic surfactant (virus stabilizer), a cryoprotectant, an osmotic pressure regulator and a buffer substance. The composition can still keep stable activity in low-temperature storage (lower than-70 DEG C), cold-chain transportation, repeated freezing and thawing and temporary storage at room temperature (10-30 DEG C). The invention also relates to application of the composition in medicine.

The invention discloses a natto peptide sea cucumber polysaccharide liposome for synergistically improving cardiovascular health and a preparation method and application thereof, belongs to the field of active peptide delivery systems, and aims to solve the stability problem of natto oligopeptide in gastrointestinal digestive tracts. The phytosterol and the vitamin E are filled between phospholipid double layers of the liposome to support a gap between the phospholipid double layers, and the ratio of the phytosterol to the vitamin E is (1-3): 1, so that the natto oligopeptide liposome has the effects that the storage of the natto oligopeptide and the stability of the natto oligopeptide in gastrointestinal and digestive tracts can be improved, the bioavailability of the natto oligopeptide liposome is improved, and the bioavailability of the natto oligopeptide liposome is improved. The traditional Chinese medicine composition has synergistic effects in the aspects of anticoagulation, thrombolysis and blood fat reduction, and has a good cardiovascular protection effect.

The invention relates to the technical field of chemical production, and discloses a continuous production process and a production system of paraformaldehyde. The continuous production process of the paraformaldehyde comprises the following steps: feeding a low-concentration formaldehyde aqueous solution into a formaldehyde concentration tower for reduced-pressure flash evaporation to obtain a high-concentration formaldehyde aqueous solution; pumping the obtained high-concentration formaldehyde aqueous solution into a spray granulation tower for spray granulation to prepare a paraformaldehyde material; and feeding the obtained paraformaldehyde material into a fluidized bed dryer for fluidized drying to obtain a paraformaldehyde product. By adopting a specific combination mode of flash evaporation, spray drying and fluidized drying, the polymerization degree of the prepared paraformaldehyde product is 9-11, and the purity can reach 92-96 wt%. And in cooperation with heat preservation and flow rate control, the polymerization problem caused by too high local concentration of formaldehyde can be effectively avoided, and the continuous production mode can be well met.

The invention belongs to the technical field of functional coatings, and particularly relates to application of an in-situ growth three-dimensional ZIF-8 / MXene composite material in preparation of a zinc-iodine battery. The protective coating prepared by the method comprises a composite material and a binder, the protective coating is attached to the surface of a zinc electrode, the composite material is composed of an MXene two-dimensional nanosheet and ZIF-8 nanoparticles, and the ZIF-8 nanoparticles are uniformly distributed on the MXene two-dimensional nanosheet. The invention further discloses a specific preparation method of the coating, the prepared coating can effectively avoid aggregation of MXene nanosheets, an electric field is uniform through charge redistribution, the cycle life of a Z-coated M-Zn negative electrode exceeds 1050 h under the current condition of 1 mA cm <-2 >, the corrosion resistance is excellent, and the total battery performance exceeds 2400 circles. The research provides a simple and convenient method for designing the reversible zinc negative electrode, and is expected to be widely applied to other metal-based negative electrode systems.

The invention belongs to the technical field of high polymer material preparation, and relates to a preparation method and application of antibacterial transparent nylon. The preparation method comprises the following steps: adding nylon, a cross-linking agent and a catalyst into a modified cyclodextrin solution for grafting reaction to obtain cyclodextrin grafted nylon; adding the cyclodextrin grafted nylon into a nano-scale metal ion solution, and then filtering, washing and drying to obtain the antibacterial transparent nylon. According to the invention, a cyclodextrin grafting process is adopted to weaken the crystallinity of the nylon material so as to improve the light transmittance, and meanwhile, nano metal ions are successfully captured and fixed by virtue of a special structure of cyclodextrin, so that the material is endowed with excellent antibacterial performance and does not need to depend on a traditional coupling agent. It is ensured that the nylon material still has good overall performance after antibacterial modification, and a new thought is provided for developing an efficient compatibility technology and exploring and innovating a modification strategy for the nylon material.

The utility model provides a water treatment agent mixing device, which belongs to the technical field of environmental governance, aims to solve the problem that during agent adding, after agents uniformly enter a stirring barrel body from an agent adding opening, the agents are extremely easy to agglomerate due to the fact that the agents are gathered below the agent adding opening, and comprises the stirring barrel body, the dosing hopper is fixedly connected to the outer side of the top end surface of the stirring barrel body; the distributing screen is arranged on the upper side of the inner end of the stirring barrel body in a reciprocating sliding manner; the stirring paddle is arranged on the lower side of the inner end of the stirring barrel body; the defoaming auxiliary net is concentrically and fixedly connected to the outer side of the top end surface of the stirring paddle; the stirring auxiliary mechanism is arranged between the stirring barrel body and the stirring paddle; the material distribution auxiliary mechanism is arranged between the guide auxiliary shaft and the material distribution screen; according to the chemical dosing device, the phenomenon that chemicals are gathered below the chemical dosing hopper and the phenomenon that the chemicals are agglomerated are avoided, the mixing efficiency of the chemicals and sewage is improved, and the reaction time of the chemicals and the sewage is shortened.

The invention relates to the technical field of pesticide preparations, and provides a pyriproxyfen-containing nano-emulsion and a preparation method thereof, and the pyriproxyfen-containing nano-emulsion comprises pyriproxyfen, an emulsifier, a thickener, water and an organic solvent. According to the pyriproxyfen-containing nano-emulsion provided by the invention, the nonionic emulsifier with a relatively high HLB (Hydrophile-Lipophile Balance) value and the lipophilic emulsifier with a relatively low HLB value are compounded, so that a mixed adsorption layer can be formed on an oil-water interface, the interfacial tension is effectively reduced, and an oil phase and a water phase are more easily mixed to form the stable nano-emulsion; the strength of an interfacial film of emulsion drops in the nano-emulsion can be improved, so that the external factor resistance of the nano-emulsion is improved, the phenomena of layering, demulsification and the like of the nano-emulsion in the storage process are not easy to occur, and the long-term stability of the emulsion is improved; besides, release and absorption of pyriproxyfen in the nano-emulsion can be optimized, so that the nano-emulsion shows a relatively high diffusion rate, and a relatively good insecticidal effect is more easily exerted.

The invention discloses betulinic acid derivatives containing amide and secondary amine structures and a preparation method and application of the betulinic acid derivatives, and belongs to the technical field of medicines.The betulinic acid derivatives are obtained by conducting structural modification on betulinic acid, and it is proved through an in-vitro thioflavin (Th) T fluorescence experiment that the betulinic acid derivatives have a good application prospect. The compounds can effectively inhibit aggregation of beta-amyloid protein (A beta) 42, can be used as candidate drugs for treating Alzheimer's disease, and have good application prospects in clinic.

The invention discloses a coating material for resisting hydrogen embrittlement in a high-temperature environment and a preparation method of the coating material, diffusion and aggregation of hydrogen atoms are effectively inhibited through a multi-layer structural design, and crack propagation and mechanical property deterioration caused by hydrogen embrittlement in the high-temperature environment are remarkably reduced. According to the coating, under the synergistic effect of the composite ceramic layer, the rare earth doping layer and the metal matrix and oxide composite layer, the hydrogen permeation resistance is greatly enhanced, the oxidation resistance and the fatigue resistance are improved, internal stress accumulation is remarkably reduced, and coating falling and structure cracking are effectively prevented. The coating material can provide more reliable long-term stability and mechanical performance under harsh conditions of high temperature, high pressure, corrosive gas and frequent thermal circulation, greatly prolongs the service life of equipment, reduces the maintenance cost, and effectively improves the safety and reliability of operation.

The invention discloses high-temperature large-temperature-difference early-strength low-density well cementation cement slurry and a preparation method thereof, and relates to the technical field of oil and gas well cementation. The well cementation cement slurry comprises the following components in parts by mass: 100 parts of oil well cement; 15-35 parts of a high-temperature strength stabilizer; 10-30 parts of a lightening agent; 0.2 to 0.6 part of an early strength agent; 0.3 to 0.7 part of a high-temperature suspension stabilizer; 1-5 parts of a high-temperature fluid loss agent; 0.3 to 0.7 part of a high-temperature retarder; and 50-70 parts of water. The problems that in the prior art, large-temperature-difference low-density cement paste is poor in rheological property, too large in water loss, poor in high-temperature stability, slow in strength development and the like are solved, safe well cementation construction of a long-sealing-section easy-leakage stratum is achieved, and therefore efficient and safe exploitation of deep stratum oil and gas resources is guaranteed.

The invention provides fuel coal water slurry and a preparation method thereof. The fuel coal water slurry comprises pulverized coal, water, an additive and a carbon-based nano material modifier, the additive comprises a dispersant and a stabilizer, the carbon-based nano material modifier has a tubular structure or a layered structure, and the average pipe diameter or interlayer spacing of the carbon-based nano material modifier is smaller than the average pore diameter of the pulverized coal. Compared with fuel coal water slurry not containing the carbon-based nano material modifier, the coal water slurry can reduce the combustion temperature, inhibit mineral substance pyrolysis and generation of nitrogen oxides and carbon monoxide, thereby reducing the heat loss of coal combustion. The carbon-based nano-material modifier has a tubular structure or a layered structure, and compared with other ranges, the average pipe diameter or interlayer spacing of the carbon-based nano-material modifier is limited to be smaller than the average pore diameter of the pulverized coal, so that water can leave a coal particle pore structure and enter the carbon-based nano-material modifier, the volatilization temperature of the water in the combustion process is reduced, and the combustion efficiency is improved. Therefore, the calorific value of the fuel coal water slurry is improved.

The invention discloses a backwashing device for a generator filter, and belongs to the technical field of filtering equipment. The filter shell is provided with a water inlet pipe and a water outlet pipe; the filtering assembly comprises a rotatable filtering cylinder, the upper end and the lower end of the filtering cylinder are in sliding connection with the inner wall of the filter shell, the filtering cylinder can rotate around the axis of the filtering cylinder, a sewage cavity communicated with the water inlet pipe is formed in the filtering cylinder, and a purified water cavity communicated with the water outlet pipe is formed by the filtering cylinder and the inner wall of the filter shell; the flushing unit comprises a water spraying pipe, the two ends of the water spraying pipe are fixedly connected with the inner wall of the filter shell respectively, a nozzle opposite to the outer wall of the filter cartridge is arranged on the water spraying pipe, and an inner cavity of the water spraying pipe is communicated with a water source through a pipeline. The filter can be backwashed, and the cleaning effect is good.

The utility model discloses a butyl acrylate reaction system with a spraying function, and belongs to the technical field of butyl acrylate preparation. According to the technical scheme, the device comprises a dehydrating tower, a first esterification reactor and a second esterification reactor which are connected through pipelines, the dehydrating tower is provided with a raw material butanol feeding pipeline, a catalyst reflux pipeline, a tower top discharging pipeline, a first evaporator feeding pipeline and a second evaporator feeding pipeline, one end, far away from the dehydrating tower, of the tower top discharging pipeline is connected with a tower top liquid receiving tank, and a tower top reflux pipeline is further arranged between the dehydrating tower and the tower top liquid receiving tank; a dehydrating tower washing liquid reflux pipeline is also arranged between the dehydrating tower and the first esterification reactor; the tower top liquid receiving tank is connected with a liquid receiving tank water phase water outlet pipeline; and the first esterification reactor is communicated with the second esterification reactor through a first reactor discharge pipeline. According to the utility model, the recycling of the catalyst is realized, low-temperature water entering the esterification reactor is reduced, and the steam consumption is reduced.

The invention belongs to the field of medicines, and particularly relates to application of odd-carbon saturated medium and long-chain fatty acid in preparation of a medicine for treating polyglutamine diseases. Research results of the invention show that the heptadecanoic acid can significantly delay and inhibit the aggregation of polyglutamine (polyQ) disease proteins, and can significantly prolong the survival time of AM141 nematodes at the same time, and the prolonging effect is about 10%. Therefore, the heptadecanoic acid is completely possible to be used as a raw material to prepare related medicines, so as to treat polyQ diseases. In addition, the heptadecanoic acid is clear in component, low in price and easy to obtain, and is more beneficial to benefiting the public.

The invention provides a nano material for a cutter and a preparation method and a product of the nano material, and relates to the technical field of metal materials. The nanometer material is prepared from the following raw material components in parts by weight: 60 to 80 parts of graphene, 10 to 25 parts of nanometer magnesia powder, 10 to 20 parts of nanometer cobalt powder, 5 to 10 parts of lanthanum oxide, 10 to 20 parts of yttrium oxide, 20 to 35 parts of chromium carbide, 20 to 35 parts of a ball milling regulator, 5 to 15 parts of iron powder, 1 to 3 parts of calcium sulfide and 0.5 to 1.5 parts of boron powder. The average particle size of the chromium carbide is 20-50nm. All the components are dispersed and then subjected to intermittent ball milling treatment to obtain the nanometer material, the nanometer material is used for preparing the cutter by controlling the sintering temperature, the heating rate and the time and adopting a gradient heating and gradient cooling method, so that the internal structure of the cutter is more uniform, and the mechanical property is remarkably improved.

The invention discloses a four-step-in-one negative pressure oil-carrying shutdown method for a styrene dehydrogenation reaction system, and relates to the technical field of styrene dehydrogenation. A negative-pressure steam oil-carrying mode is adopted for the first time, after feeding of the dehydrogenation reaction system is cut off, operation of a tail gas compressor is still maintained, the normal negative-pressure working condition of the reaction system is maintained, and steam oil-carrying under the negative-pressure working condition is carried out; after oil carrying is finished, the tail gas compressor still keeps running, the pressure is gradually increased to micro-positive pressure, and catalyst scorching is conducted; and after scorching is finished, the tail gas compressor is still maintained to operate in the steam cooling and nitrogen cooling processes until nitrogen cooling is finished, the tail gas compressor is stopped, and meanwhile multiple times of starting and stopping of the tail gas compressor are optimized into one-time stopping operation in the stages of steam oil carrying, catalyst scorching, steam cooling and nitrogen circulating cooling. One-time shutdown operation of the tail gas compressor is achieved through negative pressure shutdown, the shutdown operation step sequence of the reaction system is greatly simplified, and the shutdown disposal difficulty of the dehydrogenation reaction system is reduced.

The invention relates to the technical field of concrete, and in particular to concrete containing a polycarboxylate water-reducing agent and a preparation process thereof. In order to improve the performance of concrete, the invention prepares a polycarboxylate water-reducing agent with a carboxyl protection function. The invention introduces a large number of amide groups into the water-reducing agent, so that in the process of preparing concrete, the polycarboxylate water-reducing agent can be gradually hydrolyzed to generate carboxyl groups in an alkaline environment, and then the cement particles in the concrete are subjected to secondary adsorption, thereby prolonging the working time of the water-reducing agent on the cement particles. In addition, the invention further increases the length of the side chains in the water-reducing agent, provides steric hindrance, further prevents the aggregation between cement particles, improves the water-reducing property, thereby avoiding the solidification between cement particles, maintains the fluidity for a long time, and prolongs the construction time of the concrete.