143results about How to "Loose structure" patented technology

The invention discloses a water-retaining controlled-release fertilizer and a preparation method thereof, and relates to the technical field of controlled-release fertilizers. According to the invention, the attapulgite is modified by a phosphoric acid solution, so that the surface of the attapulgite has acidic groups, and the groups can be adsorbed with positive ions in the fertilizer, so that nutrients are adsorbed and fixed on the surface of the attapulgite, and the speed of releasing the fertilizer nutrients into a soil solution is delayed; meanwhile, the modified attapulgite and some nutritional ingredients in the fertilizer can form indissolvable compounds, so that the nutrients are slowly released along with gradual dissolution of the compounds, and the fertilizer efficiency of the fertilizer is prolonged; when the modified attapulgite encounters water, the entering speed of water can be effectively slowed down, dissolution of nutrients in fertilizer particles is controlled, and then the slow and controlled release effect is achieved; and the modified attapulgite can regulate the pH value of the soil, so that the soil environment is more suitable for plant growth and slow release of fertilizer nutrients.

The invention discloses an adjustable tension device for high-speed wire stranding, and relates to the technical field of wire stranding devices.The adjustable tension device comprises an operation table, an adjusting frame is slidably connected to the operation table, a wire stranding disc is installed on the adjusting frame, a dust collector is arranged on one side of the wire stranding disc, and the dust collector is arranged below a thread limiting sliding barrel and a rubber extrusion shaft; the driving fluted disc component is driven by the motor to rotate, the threaded limiting sliding cylinder component is further driven to move by means of the precise meshing effect of the driving fluted disc and the meshing disc, and the trapezoidal extrusion block component is driven to apply pressure to the sliding shaft. By means of the series of mechanical actions, accurate adjustment of the rubber extrusion shaft component is ingeniously achieved, and therefore the contact distance between the rubber extrusion shaft and the surface of the wire harness rod is changed. The adjustment of the contact distance is directly related to the tension generated when the wire harness rod slides on the rubber extrusion shaft, and more flexible and accurate tension control options are provided for users.

The invention discloses a cultivation and production technology of a flue-cured tobacco variety Yuzhou 201. The cultivation and production technology comprises the following steps: (1) selecting a tobacco field; (2) performing winter ploughing and ridging; (3) sowing time; (4) scientific transplanting; (5) balanced fertilization; (6) field management; (7) tobacco field plant protection; (8) harvesting; and (9) tobacco leaf baking. The tobacco leaves planted and harvested through the method are high in quality, sensory evaluation results show that the smoking quality of the tobacco leaves meets industrial requirements, and the overall sensory quality of the tobacco leaves planted through the method shows that the tobacco leaves are rich and comfortable in fragrance, good in fragrance quality, obvious in sweetness, high in fragrance amount, high in smoke concentration and moderate in strength; the high-quality strong-flavor tobacco leaf raw material is high in quality, low in irritation, comfortable in aftertaste, small in offensive odor and high in overall smoking quality, and meets the requirements of high-grade cigarettes.

The invention discloses a graphene-coated hard carbon negative electrode material and a preparation method thereof, and belongs to the technical field of hard carbon negative electrode materials. The preparation method of the graphene-coated hard carbon negative electrode material comprises the following steps: carrying out pretreatment and three-step soaking on coconut shells, carrying out biomass carbonization, mixing with a microbial suspension, and adsorbing to obtain a microbial adsorption type hard carbon material; and then carrying out surface treatment, chemical vapor deposition, impregnation, secondary chemical vapor deposition and annealing treatment on the microbial adsorption type hard carbon material to obtain the graphene coated hard carbon negative electrode material. The negative electrode material prepared by the method is high in first discharge capacity, high in first coulombic efficiency and good in cycle performance.

The invention discloses bacillus pumilus, a complex microbial inoculant and application of the complex microbial inoculant in a saline-alkali soil four-dimensional improvement method, and belongs to the technical field of microorganism application. According to the invention, a strain of bacillus pumilus is screened, and the bacillus pumilus has excellent saline-alkaline tolerance, has multiple functions of producing organic acid, proline, siderophore, trehalose, IAA and betaine and the like, and has obvious advantages in saline-alkali soil improvement; the stress resistance of plants is improved through multiple mechanisms, nutrient absorption is promoted, the soil structure and chemical environment are improved, the stability and diversity of soil microbial communities are enhanced, and then effective treatment on the saline-alkali soil is achieved. According to the four-dimensional improvement method for the saline-alkali soil, the microbial technology, the physical technology, the chemical technology and the nutrition technology are combined, the saline-alkali soil is improved from the four dimensions of physics, chemistry, biology and nutrition, soil can be effectively improved, and repeated planting is not likely to happen.

The invention provides a special fertilizer for highland barley in Tibet high-altitude areas, which specifically comprises a matrix, a base fertilizer, an organic fertilizer, a trace element fertilizer, a modifier and a nutritional agent in a mass ratio of 100: 50: 100: 1: 15: 3, the substrate comprises loam, river sand and bentonite; the base fertilizer comprises nitrogenous fertilizer, phosphatic fertilizer and potash fertilizer; the organic fertilizer comprises bran, decomposed straw, decomposed excrement, plant ash and aquatic animal powder; the modifier comprises wormcast, silkworm excrement, perlite and vermiculite; the nutritional agent comprises compound vitamins, glucose, honey and compound amino acids; the raw materials used in the method are green, safe and pollution-free, the soil structure is improved while nutrient substances needed by highland barley growth are provided, the bran, the straw, the decomposed excrement and other agricultural wastes are used, cost is saved, efficiency is improved, and the utilization rate of resources is increased.

The invention belongs to the field of planting nutrient soil, and particularly relates to a functional vegetable seedling substrate based on vegetable straw modification. The substrate is prepared from the following components in parts by weight: 6 to 7 parts of peat, 3 to 4 parts of tomato straw decomposed base material, 1.5 to 2 parts of perlite, 0.1 to 0.3 part of nutrient element loaded biochar, 0.1 to 0.2 part of mineral source potassium humate and 0.01 to 0.03 part of diatomite. According to the invention, a high-quality tomato straw decomposed base material is produced by adopting a rapid decomposition process, a tomato straw modified biochar base material is produced by adopting an anaerobic pyrolysis process, and through efficient compatibility of nutrient elements, mineral elements and the like, a new process and a new product of the functional vegetable seedling culture substrate based on tomato straw modification are produced.

The invention discloses a planting management method of flue-cured tobacco variety Heiluo No.1, and relates to the technical field of flue-cured tobacco planting, comprising the following steps: (1) tobacco field selection; (2) performing winter ploughing and ridging; (3) sowing time; (4) scientific transplanting; (5) balanced fertilization; (6) field management; (7) tobacco field plant protection; (8) harvesting; the tobacco leaves planted and harvested through the method are high in quality, the smoking quality requirement of the tobacco leaves is reflected through a sensory evaluation result, and the overall sensory quality of the tobacco leaves planted through the method shows that the tobacco leaves are rich and comfortable in fragrance, good in fragrance quality, obvious in sweetness, moderate in fragrance amount, medium in smoke concentration, moderate in strength and small in irritation; the tobacco is a high-quality tobacco raw material which is comfortable in aftertaste, light in offensive odor and high in overall smoking quality and meets the requirements of high-grade cigarettes.

The invention provides a preparation method of an antireflection film of a semiconductor laser, and belongs to the technical field of semiconductor lasers. The problem that a film layer falls off in an existing anti-reflection film preparation process is solved. Comprising the following steps: pretreatment cleaning before bar coating: vacuumizing a chamber of reaction magnetic control equipment to a vacuum degree of 10 <-6 > Torr grade, turning on a heating lamp to heat the chamber to a set temperature, starting an ion source, introducing a proper amount of plasma gas into the ion source, introducing a proper amount of plasma gas into the chamber to enable the vacuum degree of the chamber to reach a 10 <-3 > Torr grade, and then cleaning; in the process steps of plating the silicon nitride thin film and the aluminum oxide thin film, a chamber is kept at a certain temperature, and then the vacuum degree of the chamber is reduced during film plating; and the performance of the laser is stably improved while the production yield of the semiconductor laser is improved.

The invention relates to the field of a Maotai-flavor liquor brewing process, in particular to a Maotai-flavor liquor stacking fermentation method for improving the yield and quality of base liquor of Maotai-flavor liquor, which comprises the following steps: a, conveying fermented grains to a stacking fermentation process after being subjected to a cooking and gelatinization process, a steaming and steaming process, a spreading and airing process and a yeast adding process; b, during upper pile stacking, the upper pile temperature of the saccharification pile is in a range of 23-32 DEG C; when the fermented grains are piled up, at least two saccharification piles are piled up in the same team at the same time, and the weight of the fermented grains piled up on each saccharification pile each time is smaller than 400 kg; the time interval of stacking the fermented grains each time is greater than 60 minutes; the pile height is 1.5 m to 2 m, the pile bottom diameter is 4 m to 6 m, the single saccharification pile capacity is 22 to 24 retorts / pile, and the single retort capacity is 800 to 1300 kg / retort; c, after stacking is completed, the stacking saccharification duration of the sand discharging stage and the sand making stage is not less than 36 h, and the stacking saccharification duration of the first-time wine stage to the sixth-time wine stage is not less than 84 h; and d, when the accumulation is completed, the accumulation temperature of the saccharification pile is in a range of 28-55 DEG C.

The invention provides a cow dung organic controlled-release fertilizer and a preparation method thereof. The preparation method comprises the following steps: preparing porous cow dung biochar; preparing a cow dung organic fertilizer; uniformly mixing and stirring the porous cow dung biochar, the natural fibers in the treated cow dung and the cow dung organic fertilizer, and extruding and granulating in a granulator at normal temperature; drying to obtain the composite porous cow dung biochar with the sea urchin structure; preparing a hydrogel membrane solution, soaking the composite porous cow dung biochar with the sea urchin structure in the hydrogel membrane solution, and drying to obtain the cow dung organic controlled-release fertilizer. The cow dung organic controlled-release fertilizer formed by wrapping the cellulose hydrogel film layer with the composite porous cow dung biochar with the sea urchin structure is adopted, the porous cow dung biochar retains organic matter and nutritional ingredients in cow dung, and meanwhile moisture and pathogenic microorganisms are reduced through the carbonization process; the organic fertilizer is suitable for release and utilization of long-acting nutrient substances, the cow dung organic fertilizer is slowly released and utilized firstly, and the cow dung biochar is released and utilized for a long time.

The utility model belongs to the technical field of noise reduction barriers, and particularly relates to a sound barrier with a multistage noise reduction structure, which comprises a sound barrier plate, a noise reduction device is arranged in the sound barrier plate, and a splicing device is arranged on the right side of the sound barrier plate. According to the sound barrier with the multi-stage noise reduction structure, noise waves are absorbed and converted into kinetic energy through the noise reduction springs, noise is reduced, noise is further absorbed through noise reduction cotton on the inner wall of the noise reduction pipe, and the noise reduction effect is improved; meanwhile, an extension spring is compressed, then a splicing block on the other sound barrier plate is inserted into a splicing groove in the right side of the first sound barrier plate, then an insertion rod is loosened, the extension spring is reset under the self-elasticity effect, and therefore the insertion rod is pulled to be inserted into an insertion hole in the splicing block, and installation of the two sound barrier plates is completed rapidly; and the installation efficiency is improved.

The utility model relates to the technical field of foundation pit soil body reinforcement, in particular to a foundation pit soil body reinforcement device which comprises a guide pipe, a conical head is movably installed at the bottom end of the guide pipe, an anti-blocking mechanism is arranged between the guide pipe and the conical head, and a pressing disc is arranged at the top end of the guide pipe. And a supporting plate is movably mounted at the top end of the guide pipe. The guide pipe, the conical head and the supporting plate are matched for use, the conical head is kept downward during pressing, the conical head is of a conical structure, so that when the conical head is pressed into soil, resistance is small, the discharging hole is attached to the pipe wall of the guide pipe, breakage cannot be caused, and due to the fact that the outer diameter of the conical head is larger than that of the guide pipe, the conical head is not prone to falling off. When the discharge hole is exposed, a large amount of soil does not exist on the outer side of the discharge hole, and even if a small amount of soil exists, due to the fact that the soil is chiseled, the structure is loose, and filling is more convenient.

The invention discloses a preparation method of a cobalt-loaded porous skeleton-shaped graphite phase carbon nitride catalytic material, which comprises the following steps: (1) dissolving melamine in deionized water in an oil bath state to obtain a melamine solution; dissolving cyanuric acid in deionized water in an oil bath state to obtain a cyanuric acid solution; (2) slowly dropwise adding a cyanuric acid solution into a melamine solution, fully stirring, carrying out suction filtration, washing, drying, and pyrolyzing in a nitrogen atmosphere to obtain a g-C3N4 carrier; and (3) dispersing a divalent cobalt salt and the g-C3N4 carrier in deionized water, fully stirring, centrifuging, collecting a precipitate, freeze-drying, and pyrolyzing in a nitrogen atmosphere to obtain the Co-g-C3N4 catalytic material. The porous framework-shaped graphite phase carbon nitride prepared by the method is formed by tightly stacking a large amount of flaky and tubular graphite phase carbon nitride, the surface of the porous framework-shaped graphite phase carbon nitride is porous, the structure is loose, and abundant attachment sites are provided for attachment of cobalt atoms.

The invention discloses a preparation method and application of an efficient desulfurizing agent, and belongs to the technical field of desulfurizing agent preparation. The preparation method of the efficient desulfurizing agent comprises the following steps: step 1, adding ferric salt and magnesium salt into a container containing distilled water, stirring and dissolving to obtain a mixed solution A, then adding a modified template agent and a pore-forming agent into the container containing distilled water, stirring and dissolving to obtain a mixed solution B; 2, uniformly mixing the mixed solution A and the mixed solution B, heating and stirring to obtain a colloidal solid C, freeze-drying the colloidal solid C, calcining and grinding to obtain a spongy composite oxide; and step 3, adding the spongy composite oxide into a tetrahydrofuran solution containing the modifier, sealing and stirring, putting into a reaction kettle, carrying out hydrothermal reaction, and after the reaction is finished, filtering, washing and drying to obtain the efficient desulfurizer. The high-efficiency desulfurizing agent prepared by the method has an excellent desulfurizing effect.

The invention relates to LA / SA / PVA composite hydrogel, a preparation method thereof and application of the LA / SA / PVA composite hydrogel in treatment of blast furnace gas washing wastewater. The preparation method comprises the following steps: adding sodium alginate into a sodium lignin sulfonate solution to obtain an LA / SA solution, dropwise adding the LA / SA solution into a calcium chloride solution to obtain an LA / SA composite hydrogel, adding the LA / SA composite hydrogel into a glutaraldehyde solution, adding a polyvinyl alcohol solution for modification, filtering the mixture obtained by reaction, and freeze-drying to obtain the target product LA / SA / PVA composite hydrogel. According to the invention, the problems of poor adsorption effect, low mechanical strength and the like of single sodium alginate hydrogel are solved, and the composite hydrogel mainly comprising natural polymer organic matter sodium alginate and sodium lignin sulfonate coated polyvinyl alcohol is prepared through a physical cross-linking method and a chemical modification method. The composite hydrogel can be circularly used for deep treatment of blast furnace gas washing wastewater, is good in treatment effect and low in treatment cost, and has relatively good popularization and application prospects.

The invention belongs to the technical field of heat-insulating bricks, and particularly relates to a heat-insulating refractory brick and a preparation method thereof. The heat-insulating refractory brick is prepared from the following raw materials in percentage by mass: 20-60% of secondary quartzite aggregate of 0.5-0.1 mm, 30-70% of secondary quartzite fine powder of less than 0.1 mm, 5-10% of clay and 3-10% of a mineralizer, 30-40% of modified straw powder and 3-5% of a binding agent are additionally added. The heat-insulating refractory brick disclosed by the invention is excellent in high-temperature volume stability, low in preparation cost, small in volume density and light in weight, the apparent porosity is up to 60%, and the requirements of the heat-insulating refractory brick for a high-temperature kiln are met.

The invention relates to the technical field of antibacterial peptide extraction, and particularly discloses a marine organism antibacterial peptide component extraction process which comprises the following steps: S1, degreasing treatment; step S2, crude extraction; s3, electric field modification; step S4, performing enzymolysis; step S5, fine purification; according to the technical scheme, a buffer solution is added in the crude extraction process, meanwhile, shearing auxiliary heat treatment is matched, an acid value adjusting solution and hydroxytyrosol are added in the electric field modification process, and functionalized silica gel is added in the fine purification process to adsorb enzymatic hydrolysate. The purity and the yield of the antibacterial peptide component are improved.

The invention relates to the technical field of batteries, and provides a formation method for reducing the DCR of a battery, and the formation method comprises the following steps: injecting an electrolyte into a battery cell, and carrying out formation by adopting a three-step constant current charging mode: first-step constant current charging: the current rate I1 is 0.01-0.05 C, and the charging time t1 is less than or equal to 50min; in the second step, the current multiplying power I2 is 0.05 C to 0.2 C, and the charging time t2 is smaller than or equal to 60 min; the third step of constant-current charging, wherein the current multiplying power I3 is 0.2 C-0.5 C, and the charging time t3 is smaller than or equal to 100 min; wherein the large-current formation SOC is smaller than or equal to 35%, and the total formation SOC is smaller than or equal to 40%. When large current is formed, the SEI film structure is looser, the corresponding thickness is larger, and more irreversible reactions exist; during low-current formation, SEI film molecules are easier to accumulate in order, the structure is more compact, and the corresponding thickness is smaller. The total formation SOC and the large-current formation SOC are controlled, the DCR of the battery can be effectively reduced, and the rate capability and the cycling stability of the battery are improved; and meanwhile, the time and the power consumption required by the formation process can be reduced, and the equipment and production cost is saved.

A method for preparing coarse-grain or ultra-coarse-grain hard alloy by using waste hard alloy relates to the technical field of waste hard alloy regeneration, and adopts the technical scheme that the method comprises the following steps: step 1, carrying out vacuum calcination treatment on the waste hard alloy, keeping the temperature at 2000-2400 DEG C for 2-4 hours, and controlling the vacuum degree at 2000-3000 Pa; 2, hard alloy raw material powder is prepared; step 3, preparing a mixture; and 4, the mixture is subjected to granulation, compression molding and sintering, and the coarse-grain or ultra-coarse-grain hard alloy is obtained. According to the method, the waste hard alloy is calcined at the proper calcination temperature, the proper heat preservation time and the proper vacuum degree, low-melting-point metal impurities can be removed, volatilization of binding phase metal at the ultrahigh temperature is inhibited, WC crystal grains in the waste hard alloy are promoted to grow, and the calcined waste hard alloy is looser in structure and convenient to crush.

The utility model relates to the technical field of door and window profiles, in particular to a profile connecting structure and an anti-falling flat aluminum alloy screen window, which comprises a connecting structure body, a first profile arranged on the lower side of the connecting structure body, a movable block mounted on one side of the first profile, a clamping jaw fixedly connected to the top of the movable block, a clamping block arranged on the upper side of the clamping jaw, and a second profile arranged on one side of the clamping block. Fixing sleeves are installed on the two sides of the second sectional material, and locking sleeves are arranged on the upper sides of the fixing sleeves. The beneficial effects of the utility model are that through the clamping connection of the clamping jaw and the clamping block, the problems that the structure is loose and the installation is not facilitated because the angle aluminum and the self-tapping screw are directly used for connection can be avoided, the screw is exposed outside and is easy to rub a door and window user and is not beautiful enough when the angle aluminum is used for fixing a profile or welding to manufacture a door and window, and the angle aluminum can be disassembled and assembled for many times and can be repeatedly used.

The invention relates to the field of refractory materials, in particular to a high-strength refractory material and a preparation method thereof, which are used for solving the problem that the existing traditional refractory material is low in strength and difficult to meet the high-standard requirement of modern industry on equipment. The high-strength refractory material comprises the following components: silicon carbide, tabular corundum, silicon powder, yttrium oxide, magnesium oxide, titanium diboride and a phosphorus-containing phenyl multi-epoxy-group binding agent, according to the preparation method, silicon carbide, tabular corundum, silicon powder, yttrium oxide, magnesium oxide and titanium diboride are taken as main raw materials, the main raw materials are endowed with excellent mechanical properties, and after a phosphorus-containing phenyl polyepoxy binding agent is added, the mechanical properties of the main raw materials can be further remarkably improved, so that the prepared refractory material has the characteristics of high strength, high temperature resistance and the like. The composite material shows high durability and reliability in a high-temperature environment, and is suitable for thermal protection in the high-temperature environment and internal construction of high-temperature equipment.

The application belongs to the technical field of food preparation, and relates to a preparation method of PE emulsion prepared from citrus peel residues and high-dietary-fiber fat-reducing mayonnaise. The preparation method of the PE emulsion is as follows: (1) the dried and crushed citrus peel residues are soaked and pretreated with acidic oxidized electrolytic water, and after the soaking is completed, the activated materials are obtained by washing, drying and sieving; (2) the activated materials are mixed with water and then subjected to water bath heating treatment, and the citrus peel residue fiber concentrate is obtained by drying the residue; (3) the citrus peel residue fiber concentrate is dispersed and then subjected to colloid mill pretreatment and wet ball milling, and the citrus peel residue-based colloid suspension is obtained after the wet ball milling; and (4) the citrus peel residue-based colloid suspension is mixed with vegetable oil and then subjected to shearing homogenization to obtain a coarse emulsion, and then the coarse emulsion is subjected to ultrasonic treatment, and finally the citrus peel residue-based PE emulsion is obtained. The problems of unstable structure, easy oxidation, poor storage stability and poor taste of the fat-reducing mayonnaise prepared by using the PE emulsion are solved.

The invention belongs to the technical field of materials, and relates to a high-performance PCR composite material and a preparation method thereof, the high-performance PCR composite material comprises 10-20 parts of polyethylene, 0.1-0.5 part of an initiator, 0.1-0.5 part of a catalyst, 50-60 parts of a PCR return material, 10-20 parts of TPU, HEMA and 5-10 parts of an antioxidant. The preparation method comprises the following steps: (1) blending the PCR return material with polyethylene to obtain a blend; (2) mixing HEMA (hydroxyethyl methacrylate), TPU (thermoplastic polyurethane), an initiator and a catalyst, and reacting to obtain HEMA-g-TPU; the blend and HEMA-g-TPU are subjected to plasma activation, and a modified blend and modified HEMA-g-TPU are obtained; and (3) adding the modified blend and the modified HEMA-g-TPU into a twin-screw extruder, adding an antioxidant, and processing by the extruder to obtain the high-performance PCR composite material particles. The problem that the mechanical property of the PCR returned material is insufficient can be effectively solved.

The utility model relates to the technical field of fabric winding, specifically a fabric winding mechanism, including bottom plate, slide rail and fixed block, the fixed frame upper end places the winding roller, the fixed frame outer wall upper end one side screw has the slide rail, the slide rail inner wall one side screw has the guide rod, the guide rod outside slide installation has the sliding block, the sliding block outer wall upper end rotation has the compression roller installed, the sliding block outer wall upper end one side welds the fixed block, the fixed block inside rotation has the pivot, the pivot one side outer wall welds the support arm, the support arm outer wall one side screw has the beating pole, can make the dust, the thread end or residual fiber that fabric body surface adheres and falls off, reached the purpose to the fabric body cleaning, ensured the cleanness of fabric body, the guarantee of subsequent winding quality, and can release the stress inside fabric body, the wrinkle of unfolding fabric body, further guarantee the winding quality of fabric body.

The utility model discloses a heat insulation and heat preservation gel structure which comprises a base plate assembly, the top of the base plate assembly is fixedly connected with a medium layer, the top of the medium layer is fixedly connected with a colloid layer, a heat insulation layer is arranged on the right side of the base plate assembly in a penetrating mode, and the front face and the back face of the base plate assembly are fixedly connected with heat preservation layers. A mineral wool layer is arranged in the heat insulation layer and used in cooperation with the heat insulation layer, a polystyrene board layer is fixedly connected to the bottom of the mineral wool layer and used in cooperation with the mineral wool layer, and a polyurethane foaming material layer is fixedly connected to the bottom of the polystyrene board layer. The polyurethane foaming material layer is used in cooperation with the polystyrene board layer. According to the gel structure, the phenomenon that the traditional heat insulation and heat preservation effect is poor is changed, various heat insulation and heat preservation materials are adopted for heat insulation and heat preservation treatment, the phenomenon of heat loss cannot occur in the using process, and the phenomenon that the using quality of gel cannot be guaranteed is avoided.

This invention belongs to the field of material surface treatment technology, specifically relating to a wafer polishing slurry, its preparation method, and its application. The wafer polishing slurry comprises abrasives, oxidants, dispersants, surfactants, pH adjusters, and water. The components of the wafer polishing slurry work synergistically, shortening polishing time and improving polishing efficiency when applied to wafer polishing. Furthermore, it significantly improves the surface quality of the polished wafer, markedly reducing scratches and defects, and lowering surface roughness to below 0.15 nm, thus meeting the surface quality requirements of fields such as power electronics and radio frequency devices.

The invention relates to the technical field of aluminum hydroxide preparation, in particular to a method for preparing superfine aluminum hydroxide particles and the superfine aluminum hydroxide particles. The method comprises the following steps: mixing a supersaturated sodium bicarbonate solution and a first Bayer process sodium aluminate solution to obtain a seed slurry containing amorphous aluminum hydroxide; wherein the solid content of the amorphous aluminum hydroxide is greater than 30g / L; and performing decomposition reaction on the second Bayer process sodium aluminate solution and the seed slurry containing the amorphous aluminum hydroxide to obtain decomposed slurry containing the superfine aluminum hydroxide particles. According to the method, the morphological characteristics of an aluminum hydroxide product generated by decomposing a sodium aluminate solution are accurately regulated and controlled on the basis of the characteristics of a large number of disordered structures of amorphous aluminum hydroxide, so that the median particle size of aluminum hydroxide particles is 0.3 mu m or less, the specific surface area is up to 15 m < 2 > / g-30 m < 2 > / g, the oil absorption is 35 mL / 100 g-45 mL / 100 g, and the weight content of caustic alkali is 0.2% or less.

This invention discloses a composite dewatering agent for sludge dewatering in wastewater treatment and its preparation method, belonging to the field of sludge treatment technology. The composite dewatering agent comprises, by weight, the following raw materials: 30-50 parts chitosan-acetylcysteine-modified coal gangue, 20-40 parts cationic starch-modified fly ash fiber, and 1-3 parts nonionic surfactant. The composite dewatering agent of this invention, comprising chitosan-acetylcysteine-modified coal gangue, cationic starch-modified fly ash fiber, and nonionic surfactant, significantly improves the sludge dewatering rate through the synergistic effect of each component, utilizing multiple mechanisms such as charge neutralization, adsorption bridging, and the release of bound water through extracellular polymer destruction. This invention fully utilizes solid waste and natural materials in the preparation of the composite dewatering agent, achieving resource utilization of solid waste while avoiding residual pollution from traditional polyacrylamide flocculants and reducing environmental hazards.

This invention discloses a composite defluoridating agent for deep defluorination of water and its preparation method. The defluoridating agent is an aqueous solution of a metal salt or an aqueous solution of a metal salt dispersed with nanoparticles. The active ingredient of the defluoridating agent contains at least three metal ions: lanthanum, aluminum, and zinc, and the molar ratio of La, Al, and Zn is 1~4:3~5:1~3. The pH of the aqueous solution is 6.0~6.5. Compared with traditional PAC, which requires more than 5 mmol / L to reduce fluoride ions to 1 mg / L, the composite defluoridating agent of this invention only requires 1.2 mmol / L (based on the total concentration of active ingredients) to reduce fluoride ions to below 1.0 mg / L, significantly reducing treatment costs and sludge production. In addition, this invention has a fast settling speed, achieving solid-liquid separation within 10 minutes. In the preferred scheme containing nanoparticles, magnetic adsorption settling can be completed within 5 minutes, greatly shortening the water treatment process cycle.