63results about How to "Reduced nucleation rate" patented technology

A coated medical device have a drug and a nucleating agent thereon. Also provided are methods of increasing or decreasing the size of drug particles on a coated substrate through the use of nucleating agents to thereby increase or decrease the release rate of the drug from the coated substrate.

The invention discloses a high practicality lithium nickel manganese oxide and a preparation method thereof. The lithium nickel manganese oxide is characterized in that manganese source, lithium source, nickel source and a certain amount of grinding aid are blended by a dry grinding mode, the lithium nickel manganese oxide material with low specific surface area is prepared by using the characteristics of slow crystal nucleation rate and little nucleation of a precursor, contact area of the material and an electrolyte is increased, cycle life of the material is increased; cation disorder degree and crystal structure dislocation of the crystal can be controlled through a multi-step calcining technology for guaranteeing the multiplying power performance of the material; the obtained lithium nickel manganese oxide coats the surface of a carbon layer by using a vapour deposition method, anchoring strength of the material and a current collector is enhanced, peeling intensity of pole sheet is enhanced, material processing property is ensured, and multiplying power performance is increased. The material has the advantages of long service life and good processing property, and is the lithium nickel manganese oxide material with high practicality, the preparation method is economic and easy to operate, and is suitable for commercialization popularization.

The invention relates to a method for preparing a nano copper particle, in particular to a novel method for preparing a nano copper particle serving as a lubricating oil additive. The synthesis method comprises the following steps of: dissolving water-soluble divalent copper salt into water; adding a proper amount of acid organic extracting agent and coating agent into the solution; extracting divalent copper ions to an organic phase; and then simply and efficiently preparing spherical nano copper particles which have good dispersion, uniform particle size and good oxidation resistance by adopting a two-step liquid phase reduction method. The method provided by the invention has the advantages such as simple process, convenience for operation, low cost, easiness for industrialization and the like; and the prepared nano copper particle has the advantages of good dispersion, uniform particle size, good oxidation resistance, good friction property and the like.

The invention discloses a microgravity solidification device for metal liquid droplets. The upper end of a tube body is a sample installation section, and a liquid quenching collector is placed in a tube at the lower end. A sample is placed at the bottom in the test tube located in the sample installation section. A heating coil sleeves the tube body and is located at the lower end of the test tube, so that the sample is located in the middle of the axial height of the heating coil. The test tube communicates with an experimental atmosphere source through a gas flow controller. A vacuum pump and the experimental atmosphere source both communicate with the sample installation section and the test tube through a gas path control end. The center of the bottom end of the test tube is providedwith a through hole, the through hole is used for dispersing a sample after being melted into droplets with different diameters, and the droplets fall freely into the liquid quenching collector at thelower end of the tube body through the tube body. With adopting of a microgravity and liquid quenching effect integrated rapid solidification technology, free falling of the metal liquid droplets inthe tube body is combined with subsequent liquid quenching shock cooling, so that rapid solidification of the large-size millimeter-level metal liquid droplets in the shorter tube body under the action of microgravity is achieved.

The invention belongs to the technical field of rolled steel, and in particular relates to a method for improving high plasticity of low-carbon silicomanganese cold-rolling phase-change induced plasticity steel. The method comprises the following steps of: selecting the low-carbon silicomanganese cold-rolling transformation induced plasticity steels, smelting and forging so as to manufacture plate blanks, heating the plate blanks to be 1100-1250 DEG C, keeping the temperature, rough-rolling and finish-rolling the plate blanks and air-cooling the hot rolled plates to be 600-750 DEGC, coiling, and subsequently pickling so as to obtain steel plates for cold rolling; cold-rolling in a rolling reduction greater than or equal to 80%; heating the cold-rolled steel plates to be (Ac3-40 DEG C) to (Ac3+30 DEG C) at a heating velocity of at least 80 DEG C/s, carrying out annealing treatment for 5-15 seconds, subsequently cooling to a bainite area of 380-450 DEG C at a velocity of 40-80 DEG C/s, carrying out isothermal treatment for 10-50 seconds, and finally cooling to the room temperature. By utilizing the preparation method, cold-rolling transformation induced plasticity steels with high and strong plasticity is obtained, and the strength of the low-carbon silicomanganese cold-rolling transformation induced plasticity steels is greatly improved on the premise that the plasticity is not lost.

The invention discloses a quenching machine accelerated cooling method for improving the strength of a normalized steel plate with the thickness specification of being greater than or equal to 50 mm. The quenching machine accelerated cooling method comprises the following steps: the normalized steel plate enters a quenching machine along a quenching machine roller way after being discharged from a quenching furnace to be subjected to water cooling, four or six low-pressure sections are confirmed to be opened according to steel varieties and specifications, and the opening degrees, the upper and lower opening degree ratios and the roller way speeds of the areas of the low-pressure sections are adjusted, so that the steel plate is naturally cooled after the 'self-tempering' temperature reaches 580-630 DEG C, wherein the water yield control parameters are as follows: the opening degree of a flow control valve at the 15 area of the low-pressure sections is 30-40%, and the opening degree of a flow control valve at the 16 area of the low-pressure sections is 35-50%; the opening degree of a flow control valve at the 17 area of the low-pressure sections is 40-50%, and the opening degree of a flow control valve at the 18 area of the low-pressure sections is 45-60%; the opening degree of a flow control valve at the 19 area of the low-pressure sections is 60-70%, and the opening degree of a flow control valve at the 20 area of the low-pressure sections is 65-80%; the steel plate cooling speed is controlled to be 8-10 DEG C/S. The water cooling uniformity is good, the plate form after the cooling is good, and the strength of the normalized steel plate can be greatly improved through water cooling.

The invention discloses a growth method of a low-stress aluminum nitride crystal. According to the growth method, rapid two-dimensional mode growth of an AIN (Aluminum Nitride) crystal is achieved ina temperature and pressure variable mode, the stress of a single aluminum nitride crystal is reduced, and the single aluminum nitride crystal which has no crack on a growth surface and has naturally grown steps is grown. According to the growth method, a temperature control process and a mode that the temperate and the pressure of a specific temperature interval are varied in the growth process are adopted, the atom nucleation rate is reduced because of high pressure and low temperatures at a former stage, the primary nucleation tidiness is improved, and substrate decomposition failure is inhibited; at a middle growth stage, the pressure is reduced, so that the growth velocity is increased, and substrate decomposition is retarded; at a later stage, the temperature and the pressure are increased, nitrogen source supply is increased, a three-dimension island growth mode is avoided, the phenomena of non-uniform deposition and relatively large stress are reduced, secondary temperature increasing is implemented after cooling, the stress inside the crystal is reduced, cracks on the surface of the crystal is healed, a silicon carbide substrate is decomposed, and thus a self-striped high-quality single aluminum nitride crystal is grown.

The invention belongs to the related technical field of additive manufacturing, and discloses a 3D printing device and method for an oriented crystal or single crystal high-temperature alloy and a product. The device comprises a forming unit, a shape righting light path unit and a forced temperature difference unit; a DOE diffraction optical element is arranged in the shape righting light path unit, and the shape righting light path unit is used for converting laser spot energy generated by a laser emitting element into uniform distribution from Gaussian distribution; the forced temperature difference unit is arranged in the forming cavity and comprises an infrared heating pipe and a cooling pipeline, heating is conducted above a cooling substrate through the infrared heating pipe, cooling is conducted in the cooling substrate through the cooling pipeline, thus an environment temperature field with the temperature strictly and gradually reduced is formed above the cooling substrate, and then crystals grow in the opposite direction of gradually-reduced temperature when a molten pool is solidified. By means of the device and the method, the temperature gradient in the molten pool can be controlled from top to bottom strictly, mixed crystals such as isometric crystals and the like are reduced or even eliminated, and layer-by-layer stable epitaxial growth of oriented crystals or single crystals along [001] is achieved.

The invention provides a lithium nickel cobalt aluminum oxide positive electrode material and a preparation method therefor. A nickel cobalt aluminum precursor is prepared by mixing a metal salt solution comprising Ni<2+>, Co<2+> and Al<3+>, and a complexing agent solution and a precipitator solution by adopting a liquid phase control crystallization method, wherein the complexing agent comprisesone or more of fluoride, an alcohol amine type compound, a phosphoric acid type compound and a carbonyl compound; and the nickel cobalt aluminum precursor and a solid-phase lithium source are mixed and sintered to obtain the lithium nickel cobalt aluminum oxide positive electrode material. Through complexing between the limited complexing agent and Al<3+>, the nucleating rate of Al<3+> is lowered,so that uniform coprecipitation and crystallization among Al<3+> and Ni<2+> and Co<2+> can be ensured, thereby obtaining the spherical Ni<x>Co<y>Al<z>(OH)<2> precursor with uniform grain fineness distribution and high tap density; and therefore, the obtained lithium nickel cobalt aluminum oxide positive electrode material is uniform in composition and high in uniformity.

The invention discloses a preparation method of high-aluminum-doped small-particle-size cobalt carbonate particles, and the method mainly comprises the following steps: preparing a mixed salt solution of soluble cobalt salt and aluminum salt, the mass ratio of the aluminum element to the cobalt element being 0.011-0.014; adding a mixed salt solution of cobalt and aluminum sulfate and an ammonium bicarbonate solution into a diluted ammonium bicarbonate solution, and preparing a cobalt carbonate seed crystal with D50 of 1.3-1.5 [mu] m by adopting a low-temperature and low-feeding-rate synthesis process; and then preparing small-particle-size cobalt carbonate particles through a subsequent synthesis growth process. The prepared cobalt carbonate has the characteristics of high aluminum doping amount and consistent overall crystallinity of particles, and the problems that aluminum in cobaltosic oxide particles obtained after high-aluminum-doping cobalt carbonate is calcined is not uniformly distributed, and the interiors of the particles are porous are effectively solved.

The invention discloses a preparation method of a high-tap-density iron phosphate material. The preparation method comprises the following steps: S1, quickly reacting a high-concentration iron sourcesolution with a high-concentration phosphorus source solution to obtain an iron phosphate seed crystal; and S2, slowly adding a low-concentration iron source solution and a low-concentration phosphorus source solution at a constant speed to realize growth of iron phosphate crystals so as to obtain the high-tap-density iron phosphate material. According to the method, the seed crystal reaction andthe crystallization reaction of iron phosphate are effectively separated, and the sphere-like micron-sized iron phosphate particles are successfully prepared. According to the spheroidic large-particle iron phosphate, primary particles are closely agglomerated, secondary particles are uniform in size, and extremely high tap density (larger than 1.05 g/cm<3>) is shown.

The invention discloses a shape-controlled preparation method of MoS2 nano particles. The shape-controlled preparation method disclosed by the invention mainly comprises the following steps: sequentially adding a molybdenum source and a sulfur source into deionized water for stirring until the substances are completely dissolved, adding acid or alkali and adjusting the pH value of a solution to acertain value, wherein the ratio of the molybdenum source to the sulfur source is (1 to 2) to (1 to 6) and the pH value is 0.1 to 14; putting the obtained solution into a hydrothermal reactor, carrying out static reaction at the reaction temperature of 160 to 350 DEG C for 2 to 72 hours; after the reaction is ended, cooling, washing and carrying out vacuum drying to obtain shape-controlled MoS2 nano particles. The synthetic method disclosed by the invention has the advantages of mild conditions, simple operation, controllable particle shape, homogeneous products, high yield and the like. The MoS2 synthesized by the preparation method disclosed by the invention has a good application prospect in the fields of gasoline and diesel hydrodesulfurization, photoelectric catalysis, lithium ion batteries, super capacitors, lubrication and the like.

A method for eliminating residual stress of a titanium part subjected to powerful spinning deformation comprises the following steps that 1, the titanium part subjected to spinning is placed in a heat treatment furnace, the temperature is increased to the target temperature of 530-560 DEG C at the heating speed of 10-52 DEG C/min, and the heat preservation time is 60-100 min; and 2, after heat preservation is conducted, cooling is conducted to 380-410 DEG C in a furnace cooling manner, and then discharging and air cooling are conducted to the room temperature. According to the process, the residual internal stress of the TA1 part after the powerful spinning deformation can be eliminated, so that the risk of deformation of a thin-walled cylinder part due to the release of the residual stress in the subsequent machining process is reduced, and the microstructure excellence and the use performance of the material are improved.

The invention relates to a preparation method of large-dimension high-quality graphene based on self limitation nucleation growth. The method concretely comprises the following steps of preparing a nickel-covered copper substrate; fast raising the temperature in the vacuum protection atmosphere; after the specific growth temperature is reached, introducing process gas to perform graphene growth. In the primary growth period, the surface of the metal is nickel; the nucleation point of the graphene can be effectively controlled. In the growth process, the copper gradually diffuses to the nickel layer to form rich-nickel copper nickel alloy; the fast growth of the nucleation point can be promoted. Along with the continuous increase of the copper ingredients in the surface layer, the large-dimension single crystal formation of the single-layer graphene can be effectively facilitated; meanwhile, the fast growth of single crystals can be maintained; a large-dimension high-quality continuous graphene film can be realized.

The invention discloses a method for preparing a ternary positive electrode material of a high-performance lithium ion battery at low ammonia concentration, and belongs to the technical field of positive electrode materials of lithium ion batteries. The method comprises the following steps: dissolving salt containing nickel, cobalt and manganese in deionized water to prepare a mixed salt solution,adding a complexing agent into the mixed salt solution, adding acid to obtain a mixed solution; continuously pumping the mixed solution and the NaOH solution into a continuous coprecipitation reaction kettle filled with bottom liquid ammonia water respectively, enabling the total ammonia concentration of the reaction kettle to be the same as the concentration of the bottom liquid ammonia water inthe reaction process, continuously reacting to obtain a precursor material, grinding and mixing the precursor material and LiOH.H2O, and sintering to obtain the lithiated ternary material. The prepared NCM622 material is good in morphology, complete in crystal structure and uniform in element distribution, the material has high discharge capacity, good cycling stability and rate capability, and atotal battery matched with graphite and a Si/C negative electrode also has good electrochemical performance.

The invention discloses a preparation method of a high-performance cellulose-based lithium ion battery diaphragm, and belongs to the technical field of lithium ion batteries. The preparation method comprises the following steps: dispersing UIO-67 nanoparticles in an organic solvent, adding cellulose acetate (CA) and polyurethane (PU), and preparing a CA/PU/UIO-67 diaphragm by adopting an electrostatic spinning process. The CA/PU/UIO-67 diaphragm prepared by the method provided by the invention has the advantages of high lithium ion transference number, good thermal stability, uniform pore size distribution, smaller pore size and the like, and can effectively delay the nucleation rate of lithium dendrites and improve the electrochemical performance of a lithium ion battery.

The invention discloses a method for producing precipitated barium sulfate and co-producing manganese chloride. The method comprises the following steps: A, preparing a barium chloride solution; B, preparing a manganese sulfate solution; C, dipping the manganese sulfate solution prepared by the step B into the barium chloride solution prepared by the step A to perform replacement reaction; D, filtering the product after performing the replacement reaction by the step C, and respectively collecting filtrate and filter cakes; E, performing SO4<2-> decontamination on the filtrate collected by the step D, filtering the decontaminated filtrate, and distilling to obtain manganese chloride; F, rinsing the filter cakes collected by the step D till no chloride ion, baking the rinsed filter cakes in an oven, grinding and sieving to obtain barium sulfate. When precipitated barium sulfate is prepared, simultaneously a byproduct, namely manganese chloride is recovered. The byproduct is high in added value, the utilization rate of the energy is effectively increased, and relatively high economical benefits can be obtained.

The invention discloses a 6061 aluminum alloy bar production method capable of eliminating coarse grain rings, and relates to the technical field of aluminum alloy machining. The technical problem that in an existing 6061 aluminum alloy bar production process, coarse grain rings frequently appear in the extrusion process, and consequently the physical performance of materials is obviously reduced is solved. The method comprises the steps of cast ingot casting, cast ingot heating, an extrusion process, bar quenching, stretching straightening and bar artificial aging. The aluminum alloy product extruded by the method has no coarse grain ring structure defect, various performance indexes meet the standard requirements, the mechanical property of the material is improved, the bearing capacity, the service life and the use safety of the material are improved, and the use risk of the material is reduced. The method is used for preparing 6061 aluminum alloy bars.

The invention relates to a preparing method of microcrystalline foam glass, and belongs to the technical field of energy-saving building materials. Coal ash serves as the raw material for producing the microcrystalline foam glass, TiO2 in high-titanium blast furnace slag is sufficiently used as the nucleation agent, the nucleation speed of glass crystallization is reduced, and a large amount of tiny CaTi21O38 crystal nucleus is formed by well mixing and dissolving the glass; a foaming agent (calcium carbonate) is wrapped by a small amount of molten material to form a bubble cavity, when the foaming time is prolonged, the heat absorbed by calcium carbonate is increased, calcium carbonate starts to be decomposed to generate a large amount of gas, the temperature in the decomposition reactionof calcium carbonate is basically consistent with the softening temperature of the basic glass material, the viscosity of the glass material is reduced, the gas pressure in the bubble is increased, the gas wall starts to be thinned and the size of the bubble is increased when the gas pressure in the bubble is larger than the surface tension of the glass material so that a bubble with a certain diameter can be formed, and the microcrystalline foam glass of the stable porous structure is formed through cooling after the foaming process ends.

The invention discloses an economical 500MPa-grade steel bar and a preparation method thereof. The economical 500MPa-grade steel bar comprises 0.20-0.25 wt% of C, less than or equal to 1.60 wt% of Mn,less than or equal to 0.80% of Si, less than or equal to 0.045% of P, less than or equal to 0.045% of S, more than or equal to 0.05% of Ti and the balance iron and inevitable impurity elements. The key Si content of the preparation method is achieved by silicomanganese and ferrosilicon alloy, and ferrotitanium is added in the tapping process; and compared with an existing 500 MPa-grade traditional vanadium and niobium hot rolling process, the alloy consumption is low, no precious metal element is contained, economical efficiency is achieved, and the cost can be reduced.