59 results about "Urea decomposition" patented technology

The invention discloses a dialysate regeneration system and dialysis equipment, the dialysate regeneration system comprises a waste liquid passage, a slow flow box, an electromagnetic valve, a reactor and an adsorption mechanism, the waste liquid passage is in through connection with the slow flow box, the slow flow box is connected with the reactor through a pipeline, and the pipeline is provided with the electromagnetic valve. The fixing amount of a urease layer is increased through the treatment film with the three cambered surfaces, the urea decomposition efficiency is improved, the diffusion path of toxins on the treatment film is shortened, meanwhile, the treatment film with the cambered surface structure can guide dialysis waste liquid entering the reactor to generate local turbulence, and the toxins are prevented from being accumulated on the surface of the treatment film; the dialyzer is arranged, the micro horse is started to drive the hollow fiber to rotate, the material exchange efficiency of blood and dialysate is improved, and the situation that protein and cells are deposited on the surface of the hollow fiber, and the service life of the hollow fiber is shortened is avoided.

The present invention discloses a microbially induced carbonate precipitation (MICP)-based vertical barrier, and a preparation method thereof, wherein a raw material of the vertical barrier includes in-situ soil, Ca-bentonite, a bacteria-containing culture medium, and a cementing solution. The bacteria-containing culture medium comprises flocculent ureolytic bacteria flora. The proportions of dry the Ca-bentonite to in-situ soil, the bacterial-containing culture medium to the cementing solution, and the cementing solution to the Ca-bentonite are specified to be 1:2, (2˜5):1, and (1˜2.5):10, respectively, to ensure optimal performance. The present invention addresses challenges related to the insufficient impermeability of Ca-bentonite-based barriers in the application of vertical barrier, and aims to reduce both the cost and carbon emissions associated with their construction.

The present invention provides an improved low-energy-consumption urea production process by CO2 stripping method. A part of the urea synthesis liquid is sent into the high-pressure CO2 stripper in the high-pressure decomposition and recovery system for stripping and decomposition, and then is sent into the medium-pressure pre-separator after being decompressed by the first hydraulic turbine or / and pressure reducing valve; another part of the urea synthesis liquid is directly sent into the medium-pressure pre-separator after being decompressed by the second hydraulic turbine or / and pressure reducing valve, and the urea solution at the outlet of the medium-pressure pre-separator is sent into the shell side of the urea decomposition heater; a part of the gas phase of the high-pressure CO2 stripper is sent into the high-pressure carbamate condenser, and another part is sent into the tube side of the medium-pressure decomposition heater, and the liquid phase at the outlet of the high-pressure ammonia ejector is also sent into the tube side of the medium-pressure decomposition heater. The carbamate liquid is sent into the high-pressure carbamate condenser after coming out of the tube side of the medium-pressure decomposition heater; the urea solution coming out of the shell side of the urea decomposition heater is sent into the medium-pressure urea rectifying column and then into the low-pressure rectifying column, and then into the slightly positive pressure flash tank. The process of the present invention is simple, low in cost and low in steam consumption.

The invention belongs to the technical field of denitration agents, and particularly discloses a composite denitration agent for an out-of-furnace phase change process and a preparation method of the composite denitration agent. The preparation method comprises the following steps: mixing 60-80 parts of urea, 20-30 parts of a hydrolysis accelerant and 5-15 parts of amino modified zeolite to obtain the composite denitration agent for the external phase change process; the hydrolysis accelerant is coated ammonium carbamate, and the amino-modified zeolite is obtained by modifying an amino-containing silane coupling agent. The prepared composite denitration agent can promote forward proceeding of urea hydrolysis, the conversion rate of urea is increased, and the ammonia yield is increased; the amino modified zeolite can adsorb and activate urea molecules, urea decomposition is transferred to a low temperature, the activation energy of urea decomposition is remarkably reduced, and the reaction rate is increased.

The invention relates to a nitrogen-doped carbon shell coated nanoparticle structure catalyst based on beta-cyclodextrin and application of the catalyst in a zinc-air battery, beta-cyclodextrin, urea and cobalt nitrate hexahydrate are directly mixed, beta-cyclodextrin is complexed on the periphery of cobalt through complexation, meanwhile, urea is used as a nitrogen source, and the nitrogen-doped carbon shell coated nanoparticle structure catalyst based on beta-cyclodextrin is prepared. Nitrogen atoms are introduced into beta-cyclodextrin, the morphology of beta-cyclodextrin complexed on the periphery of cobalt is kept after drying, urea is decomposed into a nitrogen source through high-temperature heat treatment, beta-cyclodextrin is partially carbonized to form a conductive carbon matrix, the nitrogen atoms are doped into the carbon matrix, and a nitrogen-doped carbon shell structure with high conductivity is formed. The nitrogen-doped beta-cyclodextrin coated cobalt nanoparticle catalyst with the core-shell structure is obtained, carbonized beta-cyclodextrin provides a conductive network, the electron transfer efficiency is improved, the electron structure of a carbon material is changed by nitrogen doping, the conductivity and the oxidation reduction activity are improved, meanwhile, the introduction of nitrogen atoms is beneficial to increase of the number of active sites, and the nitrogen-doped beta-cyclodextrin coated cobalt nanoparticle catalyst with the core-shell structure is prepared. Therefore, the catalytic activity of the ORR is improved.

The invention discloses a high-antimony lead production process based on lead refining alkaline residues, and belongs to the technical field of lead bullion refining alkaline residues. Through carbonization treatment after urea intercalation and urea decomposition and escape, more pores and larger interlayer spacing are left, so that the specific surface area of anthracite is increased, porous anthracite is obtained, and the specific surface area of the anthracite is increased; the porous anthracite is subjected to secondary intercalation by using nano calcium oxide, the obtained modified porous anthracite is larger in interlayer spacing and larger in surface area, a large amount of nano calcium oxide is uniformly attached to the surface of the anthracite, the reaction activity is remarkably improved, and an enlarged pore structure is beneficial to gas diffusion, so that the reduction reaction efficiency of the anthracite is improved; the zeolite-based modified asphalt powder is used as a binder, and zeolite particles can fill micro pores and cracks in the asphalt, so that the void ratio is reduced, the compactness of the asphalt is improved, and the bonding strength is improved; the lead product prepared through the production technology is high in purity, the antimony recovery efficiency is high, meanwhile, the amount of generated slag is small, and the content of lead in the slag is low.

The invention discloses a method for preparing a biobrick by using engineering bacteria, and belongs to the technical field of biological building materials. Escherichia coli engineering bacteria capable of generating urease are obtained through engineering modification of escherichia coli, an escherichia coli engineering bacteria solution is mixed with a matching solution containing urea and mineral calcium salt, then sand grains and a hydrogel adhesive are added, and under the appropriate environmental condition, urease generated by the escherichia coli engineering bacteria can catalyze urea decomposition, so that the urea decomposition rate is increased, and the urea decomposition rate is increased. Ammonia and carbonate ions are generated and then react with calcium ions to generate calcium carbonate, so that sand grains are cemented together, and the biobrick with certain strength and biological characteristics is formed. The biobrick not only has good strength, but also has certain self-repairing capability and environmental adaptability, and can be applied to the field of civil engineering as a green and sustainable building material. The preparation method disclosed by the invention is simple, efficient and environment-friendly, has important significance on the national double-carbon strategy, and has a wide application prospect.

According to the preparation method, a co-sintering pretreatment step is added, potassium carbonate and urea are co-sintered at a limited temperature to form a eutectic mixture, so that a nitrogen-containing group (such as NH3) generated by urea decomposition and the potassium carbonate are synergistically embedded into a carbon skeleton precursor, and the carbon skeleton precursor is formed. Meanwhile, urea decomposition provides a nitrogen source, efficient nitrogen doping is achieved, the nitrogen doping efficiency is improved by 50% or above compared with a traditional process, continuous production can be achieved, the production efficiency is improved, continuous activation of the rotary furnace is matched with segmented temperature control, construction of a micropore-dominated hierarchical pore structure (the micropore rate is larger than 85%) is facilitated, and the specific surface area is increased; the capacitance carbon prepared by the method has the advantages of high specific surface area, reasonable pore size distribution and the like, the specific capacitance can reach 220F / g and is increased by 40% compared with that of an undoped sample, the tap density is greater than or equal to 0.4 g / cm, and the specific capacitance is increased by 30%.

The invention relates to the technical field of chemical engineering, and discloses a method for preparing cyanuric acid by a pyrolysis method, which comprises the following steps: screening urea to remove impurities and caking parts in the urea, and storing the screened urea in a dry environment; the method comprises the following steps: adding pretreated urea into a reactor with a stirring device and a temperature control system for decomposition reaction, and leading out ammonia gas generated in the reaction process through a gas guide pipe; after the urea decomposition reaction is finished, slowly and uniformly adding a catalyst into the reactor, and carrying out trimerization reaction on the isocyanic acid under the action of the catalyst to generate cyanuric acid; the generated cyanuric acid is transferred into a pyrolysis reactor to be subjected to a pyrolysis reaction, after the pyrolysis reaction is completed, a product is naturally cooled to the room temperature, the cooled product is cyanuric acid, cyanuric acid is taken out of the reactor and smashed and screened, and cyanuric acid powder with the uniform particle size is obtained; the preparation method is simple, easy to operate and suitable for industrial production.

Method for slowing down the decomposition of urea in the soil contained in nitrogen fertilisers used for affecting plants, by applying a urease inhibitor - an enzyme that catalyses the decomposition of urea in the fertiliser to ammonia and carbon dioxide during the hydrolysis process occurring in the soil, in which the urease inhibitor used is non-ionic silver particles, obtained by a physical method, without impurities and with a purity above 99.99%, in the form of particles with an expanded active surface area, various sizes, and a number distribution of these sizes from 1 nm to 500 nm, wherein the silver particles are dosed into the fertiliser mass in the form of a colloid containing the mentioned silver particles in deionized water, to achieve a concentration in the fertiliser mass from 1 to 50 ppm.

A MnO2 catalyst for efficient catalytic purification of acetonitrile x This paper discusses SiO2@CeO2 catalysts and their preparation methods, belonging to the fields of catalysis chemistry and environmental chemistry. It involves using MnO... x MnO was prepared by loading it onto a SiO2@CeO2 core-shell structure support. x / SiO2@CeO2 catalyst. The preparation method is as follows: silica microspheres are prepared using a method similar to [preparation method], followed by SiO2@CeO2 preparation using a urea decomposition and precipitation method. The above steps are repeated to adjust the CeO2 loading. MnO is then impregnated using an impregnation method. x MnO was prepared by loading the sample onto the surface of a core-shell SiO2@CeO2 support and then calcining the sample in a muffle furnace at 450℃ for 3 hours. x / SiO2@CeO2 catalyst. This catalyst features a uniform dispersion of transition metal oxides on the support surface, exhibiting good catalytic purification performance for acetonitrile, and shows significant application potential in the treatment of nitrogen-containing organic pollutants.

The invention relates to an SCR denitration system for a test bed, and belongs to the technical field of tail gas treatment of aero-engine test beds. According to the SCR denitration system, the multiple urea spray guns are adopted, different urea spray guns can be flexibly adjusted and selected to work according to different working conditions of an aero-engine, the whole denitration is always in an efficient pyrolysis area, high efficiency is guaranteed, and it is guaranteed that the urea decomposition reaction time is enough. According to the system, the temperature in the urea storage tank is detected in real time, it is ensured that a urea solution is in the optimal uncrystallized and undecomposed state all the time, the stretching amount of a spray head is determined according to the exhaust temperature of tail gas, it is ensured that urea is at the optimal pyrolysis temperature, urea decomposition is complete, tail gas is efficiently treated, and raw materials are saved; the temperature of air around the catalyst is tested through a third temperature sensor, too little or excessive injection of urea is avoided, and the injection amount of the spray gun is adjusted to adapt to rapid change of engine work.

The invention relates to the technical field of urea-to-ammonia, and discloses a urea pyrolysis-to-ammonia system and a control method thereof.A urea storage device dissolves urea in water to obtain a urea solution; the urea distribution device distributes a urea solution according to the requirements of the pyrolysis process; the urea pyrolysis device collects a plurality of historical urea pyrolysis ammonia production records, calculates a historical urea pyrolysis ammonia production partial difference coefficient, and sets a working strategy of an electric heater; the ammonia gas separation device is used for separating the prepared ammonia gas and recycling residual by-products; the ammonia monitoring device collects real-time working parameters of the urea pyrolysis device in real time and judges whether the urea pyrolysis device has potential safety hazards or not, if yes, an alarm is given out, adaptive adjustment of the urea pyrolysis ammonia production temperature is achieved, the control precision and control efficiency of the urea pyrolysis ammonia production temperature are guaranteed, the ammonia yield is guaranteed, and the urea decomposition efficiency is improved. And meanwhile, the generation of byproducts is reduced, and efficient and stable ammonia gas production is realized.

This invention relates to a method for preparing a perlite-based adsorbent material, the resulting material, and its applications. The preparation method includes: pretreating expanded perlite particles; mixing polyaluminum chloride and urea in water to obtain an impregnation solution; subjecting the pretreated perlite to vacuum impregnation followed by atmospheric pressure soaking, allowing the impregnation solution to enter the open pores; then subjecting it to staged heating treatment to decompose the urea and release alkaline components, promoting the confined transformation and immobilization of aluminum species in the open pores and pore openings of the perlite; subsequently washing, aging, and drying to obtain the perlite-based adsorbent material. The obtained material is a granular material with a particle size of 2–6 mm, containing an aluminum-based immobilization layer on its surface and within its open pores, and can be used for the treatment of phosphorus-containing water.

The invention relates to an iodine-based positive electrode material with cobalt species confined in nitrogen-doped porous carbon for an aqueous zinc-iodine battery as well as a preparation method and application of the iodine-based positive electrode material. The iodine-based positive electrode material comprises a nitrogen-doped porous carbon carrier, a cobalt species confined in a porous carbon skeleton and an iodine active substance loaded in a pore channel. Compared with the prior art, the method has the advantages that the freeze drying and inert atmosphere pyrolysis technologies are combined, in-situ nitrogen doping on the surface of the carbon material is carried out by using the ammonia gas generated by decomposition of introduced urea, and efficient confinement anchoring of cobalt species is realized by virtue of a hierarchical pore structure derived and constructed in the pyrolysis process. The obtained positive electrode material can improve the utilization rate and the structural stability of an iodine active substance, so that the rate capability and the cycling stability of an aqueous zinc-iodine battery are improved.

The utility model discloses a device for biologically solidifying construction waste, which relates to the technical field of constructional engineering and comprises a support, a humidity control maintenance bin is fixedly connected to the inner wall of the support, a solidifying mechanism is arranged on the support, a uniform spraying mechanism is arranged on the support, and the humidity control maintenance bin is fixedly connected to the inner wall of the support. By arranging the strain culture reactor, firstly, urease-producing bacteria are cultured in the strain culture reactor, a culture medium containing urea and calcium salt is supplied for proliferation, high-activity bacterial liquid is obtained, then to-be-cured building waste crushed aggregates such as waste bricks and stones and concrete particles are flatly laid in the humidity-control curing bin, and the humidity-control curing bin is used for curing the building waste. According to the mechanism, urea in a nutrient solution is promoted to be decomposed through urease generated by bacteria, carbonate ions are formed, then the carbonate ions are combined with calcium ions to precipitate calcium carbonate crystals, adjacent particles are cemented together, building waste stacks can be reinforced into blocks or roadbed materials without traditional cementing materials such as cement, the process is environmentally friendly, and the construction waste is recycled. And new engineering value is given to the construction waste.

The invention discloses a preparation method of a MgAl-LDH / AlOOH catalyst, which comprises the following steps: taking urea, magnesium sulfate and aluminum nitrate nonahydrate as raw materials, taking ultrapure water as a solvent, and preparing the target product MgAl-LDH / AlOOH catalyst through a one-step hydrothermal method. The invention also discloses an application of the MgAl-LDH / AlOOH catalyst in catalytic treatment of antibiotic wastewater. The MgAl-LDH / AlOOH catalyst is prepared by adopting a one-step hydrothermal method, urea, magnesium sulfate and aluminum nitrate nonahydrate are selected as raw materials, hydroxyl generated by urea decomposition in the hydrothermal process is utilized, the MgAl-LDH / AlOOH catalyst with different surface Lewis acid sites is generated by adjusting the magnesium-aluminum ratio, activation of PMS and generation of active oxygen species are regulated and controlled, and the PMS-LDH / AlOOH catalyst with different surface Lewis acid sites is obtained. The efficient degradation and safe conversion of antibiotics are improved. In addition, magnesium and aluminum serve as raw materials and are cheap and easy to obtain, and the hydrothermal method is simple in preparation process and suitable for large-scale industrial production.

The utility model provides a high-speed negative pressure spraying device for a denitration skid-mounted station, which relates to the technical field of spraying devices and comprises a volute fan, and the output end of the volute fan is connected with a spraying assembly. The spraying assembly comprises a conical air spraying pipe connected with the output end of the volute fan, and the conical air spraying pipe is sleeved with a spraying pipe; the injection pipe sequentially comprises a negative pressure cavity, a folding cavity, a smooth cavity, a release cavity and a flow guide cavity from left to right. According to the utility model, negative pressure can be formed when high-speed air flow passes through the negative pressure cavity, urea powder is sucked into the negative pressure cavity to be mixed with air, and the urea powder is efficiently conveyed to a reaction area through the high-speed air flow to be fully contacted and reacted with NOx, so that the urea is decomposed into ammonia gas, and the denitration efficiency is improved; a urea solution is replaced, and the problems that a traditional liquid reducing agent injection system is uneven in injection, high in equipment complexity and poor in environmental adaptability and has leakage hidden dangers are solved.

Traditionally, diesel exhaust fluid (DEF) injection rates in diesel engine aftertreatment systems must be limited at low temperatures to prevent urea crystallization at and beyond the injection point. Urea crystallization can reduce the amount of injectable DEF, thus decreasing the efficiency of the nitrogen oxide (NOx) reduction process. x ) reduce and the like. In the disclosed embodiments, a catalyst material (350) is used upstream of the injection point to convert urea to ammonia before injection. This prevents or reduces urea crystallization at and beyond the injection point.

The invention provides a method for preparing coal-based quantum carbon dot slow-release urea through sectional drying-fluidized bed granulation, and relates to the technical field of slow-release fertilizer preparation, the method comprises the following steps: S1, coal-based waste is used as a raw material, coal-based quantum carbon dots MCQDs are prepared through a hydrothermal method, a silane coupling agent is added for surface functional modification, and a functional MCQDs dispersion liquid is obtained; s2, industrial urea is smashed and screened, and urea master batches with the particle size ranging from 1.0 mm to 3.0 mm are obtained; in the pre-drying stage, moisture on the surfaces of urea master batches is thoroughly removed through a low-humidity environment, and particle aggregation caused by moisture during MCQDs spraying is avoided; in the medium-temperature setting stage, in an interval lower than the urea decomposition temperature, MCQDs are promoted to form a covalent bond with a urea crystal face through a silane coupling agent, and the bonding stability is improved; the formed bonding structure is locked in the low-temperature curing stage, structural damage caused by temperature fluctuation is avoided, and the problem of decomposition or agglomeration is solved.

The present invention provides a long-cycle high-rate negative electrode material and its preparation method and application, which belong to the field of negative electrode material technology. By compounding silicon powder, tin powder and graphene and performing carbon coating, a three-dimensional conductive network is constructed to alleviate volume expansion and improve conductivity, cycle stability and rate performance; tungsten oxide is used as an interface stabilizer to form a protective layer, inhibit side reactions, reduce interface impedance and enhance the conductive network; metaphosphoric acid decomposes to form an inorganic phosphate protective film, which is combined with nitrogen-doped carbon generated by urea decomposition to significantly improve interface stability, conductivity and cycle life; lithium carbide reacts with vinylidene fluoride to generate a lithium fluorocarbon additive, which reduces the initial lithium loss and stabilizes the interface by releasing lithium ions in stages; a vanadium-based metal-organic framework prepared from ammonium metavanadate and terephthalic acid is combined with pre-embedded lithium and graphitized carbon coating to optimize the lithium ion transmission path and improve its performance. These synergistic modification measures improve the long-cycle stability and high-rate performance of the negative electrode material.

A urea treatment method in which hypobromite ions are generated by adding a chlorine-based oxidizer and a bromide salt to to-be-treated water containing urea so as to break down the urea in the to-be-treated water and obtain treated water, the method including: a) determining the free residual bromine concentration and the free residual chlorine concentration in the treated water; and b) controlling the added amount of the chlorine-based oxidizer and the bromide salt on the basis of the free residual bromine concentration and the free residual chlorine concentration. The device includes a bromide salt adding means, a chlorine-based oxidizer adding means, a urea decomposition tank, a residual chlorine meter, and a control device for controlling the added amount of the chlorine-based oxidizer by the chlorine-based oxidizer adding means on the basis of the method.

The invention discloses a preparation method of a boron nitride nanotube without a template and a catalyst, and belongs to the technical field of preparation of inorganic non-metal nano materials. The method comprises the following steps: dissolving boric acid and urea in deionized water to form a precursor solution; the solution is directionally frozen under the vertical one-way temperature gradient by controlling the low temperature of the bottom of the container and the room temperature of the top of the container, and a frozen body with a vertical columnar ice crystal structure is formed; performing freeze drying to obtain a precursor with axial ordered pore channels; and finally, pyrolyzing in an inert atmosphere to obtain the boron nitride nanotube. According to the preparation method, the precursor structure is precisely regulated and controlled through a directional freezing technology, and the tube is formed through directional release guidance of urea decomposition gas, so that the technical problem that a product in a template-free catalyst-free system is easy to be a nanosheet instead of a nanotube is solved. The method is simple in process and low in cost, and the product is uniform in morphology and pure.

Traditionally, diesel exhaust fluid (DEF) injection rates in aftertreatment systems for diesel engines must be restricted at low temperatures to prevent urea crystallization at and beyond the point of injection. Urea crystallization can reduce the amount of diesel exhaust fluid that can be injected, decrease the efficiency of nitrogen-oxides (NOx) reduction process, and the like. Disclosed embodiments utilize a catalyst material upstream from the point of injection to convert urea into ammonia, prior to injection. This eliminates or reduces urea crystallization at and beyond the point of injection.

The invention discloses carbonate mineral coupled hydrothermal carbon and a preparation method thereof, relates to the technical field of environmental management, and aims to solve the problems of weak resistance to oxidation, high temperature and water environments, short service life and low environmental tolerance of existing hydrothermal carbon. The method comprises the following steps: mixing and stirring biomass and pure water to obtain a mixture 1; adding metal salt into the mixture 1, mixing and stirring to obtain a mixture 2; adding urea into the mixture 2, mixing and stirring to obtain a mixture 3; and reacting the mixture 3 at high temperature and high pressure, taking out, washing and drying to obtain the carbonate mineral coupling hydrothermal carbon. Urea is introduced to serve as a carbon source in the hydrothermal carbonization process, carbonate generated by reaction of CO2 generated by urea decomposition and water at high temperature and high pressure is fully utilized to generate carbonate minerals, the carbonate minerals are embedded into pores and surfaces of hydrothermal carbon, and the oxidation resistance, the thermal stability and the solubility resistance of the hydrothermal carbon are remarkably improved.

The invention provides a special green Chinese onion nutrient solution prepared based on animal enzymes and a preparation process thereof, and relates to the field of preparation of green Chinese onion nutrient solutions. The special green Chinese onion nutrient solution prepared based on the animal enzyme is prepared from the following raw material components in parts by mass: 60 parts of animal internal organs, 15 parts of eggshell powder, 10 parts of animal blood, 25 parts of green Chinese onion leaves, 3 parts of urea, 6 parts of livestock manure, 5 parts of brown sugar and 4 parts of EM bacterial powder. Urea and livestock manure are added in the preparation process of the nutrient solution, ammoniacal nitrogen generated by decomposition of urea can be combined with carbohydrate to generate amino acid, the protein content of the nutrient solution is remarkably increased, and growth of stems and leaves of green Chinese onions and synthesis of chlorophyll are promoted; the requirements of the green Chinese onions on various nutrients can be synchronously met, so that full decomposition of raw material fermentation can be accelerated, and the fermentation efficiency is improved.

The invention relates to the technical field of environmental functional materials, and discloses a titanium dioxide nanotube preparation method, which comprises: 1, preparing an H2Ti3O7 nanotube precursor by using a hydrothermal method and a proton exchange method; 2, mixing the H2Ti3O7 nanotube with urea according to a Ti / N molar ratio of (2-3): 1 or adopting a urea solution with the concentration of 1M-3M to form a uniform mixture; 3, carrying out low-temperature evaporation drying on the mixture to remove most of the solvent; and 4, under the protection of inert gas, the inert gas is selected from argon or nitrogen. According to the preparation method of the titanium dioxide nanotube, urea is decomposed to generate NH3 and CO2, N and C atoms are provided and are synchronously embedded into TiO2 crystal lattices to form substitution doping (N replaces O site) and interstitial doping (C occupies the interstitial space), and the forbidden band width is reduced to 2.1 eV-2. 8eV.

The application belongs to the technical field of plant alkaloid application, and particularly relates to application of areca alkaloid in preparation of urease inhibitor. The application discloses application of areca alkaloid in preparation of urease inhibitor, wherein the areca alkaloid comprises at least one component: (1) norarecoline; (2) norarecolin; (3) arecoline; (4) arecolin. The areca alkaloid disclosed by the application has the functions of inhibiting urease activity, reducing urea decomposition rate and regulating rumen nitrogen metabolism of ruminants; when norarecoline: arecolin: norarecolin: arecoline = 2:3:2:6, the inhibiting effect on rumen urease is better, and is equivalent to the effect of norarecoline and norarecolin; the stability and tolerance of areca total alkaloid in the rumen are better than those of positive drug acetyloxime acid.

The invention discloses a urea-based nutritional feed and application thereof in ruminants, and belongs to the technical field of enzyme engineering feed processing. According to the feed, components such as corn, urea, a urease inhibitor, carglutamic acid, potassium magnesium sulfate, bentonite and 10-hydroxy-2-decenoic acid are scientifically proportioned, so that the safe utilization efficiency of ruminants on urea is improved. The urease inhibitor controls the urea decomposition speed and reduces the risk of ammonia poisoning; carboglutamic acid further improves the utilization rate and safety of urea by accelerating blood ammonia conversion. The nutritional feed can partially or completely replace soybean meal, so that the feed cost is reduced, and meanwhile, the environmental pollution is reduced. Experiments show that the feed significantly improves the growth performance and feed conversion efficiency of ruminants, and has good economic benefits and environmental protection benefits.

The utility model belongs to the technical field of commercial vehicle emission, and particularly relates to a rotational flow heating system for accelerating urea decomposition. The rotational flow heating system comprises an electric heater, one end of the electric heater is connected with a front air inlet round flange through a cylinder, the other end of the electric heater is connected with a mixer air inlet round flange through an air outlet round flange, a center shaft is arranged in the center of the electric heater, and one end of the center shaft is located in a turbofan. The other end of the spring penetrates through the electric heater and is locked and fixed through a locking nut; two high-temperature-resistant bearings are arranged in a central mounting hole of the turbofan and are positioned between a shaft shoulder of the central shaft and the turbofan; a bearing cover plate used for sealing the high-temperature bearing is arranged at the open end of the turbofan. According to the rotational flow heating system, the electric heater device is additionally arranged at the front end of the SCR, the air flow exhaust temperature is increased, and the problems that the exhaust temperature is insufficient (lower than 200 DEG C) under cold start, and a urea nozzle does not work are solved.