32results about How to "Lower the nucleation barrier" patented technology

The invention relates to a feedback control method for crystal product granularity in the dilution crystallization process. The method includes the specific steps: estimating the sum of crystal granules according to expected average grain diameter of crystal products, comparing the sum of crystal granules N in crystallization mother liquor measured through an on-line granularity measurement apparatus in real time with the sum of crystal granules Ns specified in production, and synchronously controlling feeding rate of a crystal breaking system, dilution agent and solvent till the crystal products with expected granularity distribution are produced. Compared with the conventional granularity control method in the dilution crystallization process, the method has the advantages that the crystal products with expected granularity distribution can be produced automatically and conveniently as required by only regulating one parameter of the specified sum of crystal granules Ns without re-optimizing new process parameters and the grinding and screening process through plenty of experimental operation, and a granularity controllable regulation function of producing the crystal products with specified granularity distribution as required is realized.

The invention discloses a preparation method of a composite material, a product and application of the composite material. According to the method, a precursor solution is impregnated into polymer particles, in-situ loading of MOFs one-time forming is achieved, structural design is conducted on the porous composite material by adjusting the concentration of metal salt and organic ligands and adding an adjusting agent, and regulation and control over the size of MOFs crystals are achieved. According to the composite material prepared by the method, the space structure advantages of polyacrylamide materials which are communicated with one another and have hierarchical pore structures can be utilized; by combining with active amino on the pore wall, uniform spreading of a nano MOFs layer is realized, the mass transfer rate and the adsorption efficiency of the material in water vapor trapping are greatly improved, and the material can be suitable for water vapor trapping in different humidity environments. The method is simple in preparation mode, easy to form, high in mechanical strength and suitable for industrial production.

The invention relates to a feedback control method of the granularity for a crystal product in an intermittent cooling and crystallization process. According to the technical scheme, the feedback control method comprises the following specific realization steps: estimating the total quantity Ns of crystal particles according to an expected needed crystal product average grain diameter; comparing the total quantity N of crystal particles in crystallization mother liquid, which is determined through an online granularity detector in real time, with the total quantity Ns of the crystal particles specified by production; synchronously controlling heating and cooling speeds in a crystal crushing system II and a crystallizer until crystal products with expected granularity distribution are produced. Compared with a traditional granularity control method of the intermittent cooling and crystallization process, only one specified parameter, namely the total quantity Ns of the crystal particles, needs to be adjusted, a novel process parameter and a grinding and sieving process do not need to be optimized through a lot of experiment operation, and the crystal products with the expected specified granularity distribution can be automatically and conveniently produced according to requirements; a granularity controllable adjustment function of the crystal products produced according to the requirements and having the specified granularity distribution is realized.

The invention provides a method for complexly refining aluminum alloy solidified structure by using a current and a crystal grain refining agent. The crystal grain refining agent is added in a process of smelting an aluminum alloy and a direct current is introduced in an aluminum alloy solidifying process until an aluminum alloy is completely solidified. The method comprises the following steps of: (1) placing an electrode in a casting mould, connecting the electrode with a power supply, and adjusting current parameters; (2) smelting the aluminum alloy through conventional smelting, refining, degassing and de-slagging procedures; (3) after the temperature of an aluminum alloy mother solution is stabilized to a pre-set temperature, adding the crystal grain refining agent and agitating; and (4) pouring the aluminum alloy mother solution, simultaneously switching on the power supply, and continuously introducing the current until a casting piece is completely solidified. According to the invention, a complex method of combining physical refining and chemical is adopted, so that an aluminum alloy structure with finer crystal grains, more uniform structure and obviously-reduced defects can be obtained and he mechanical property of the aluminum alloy can be improved; and meanwhile, the situation that the industry depends on the imported crystal grain refining agent for a long period is broken through, and the method is suitable for solidifying and refining pure aluminum or the aluminum alloy.

The invention relates to the manufacturing method of a metal nanostructure array based on interface induction growth. The method comprises the following steps of 1, cleaning a substrate; 2, transferring a template, and transferring an ultrathin porous alumina template to the cleaned substrate; adjusting an adhesive force, standing a sample acquired from the step2 for several hours so that an adhesive force portion between the template and the substrate is relaxed, or through low temperature annealing, strengthening the adhesive force between the template and the substrate; 4, depositing metal,and depositing the metal on the surface of the sample obtained from the step3 by using a physical vapor deposition method; and 5, peeling the template, after the deposition is completed, using an adhesive tape to peel the template so that an ordered metal nanostructure array is left on the surface of the substrate, wherein under an adhesive force relaxation condition, an ordered nano-pore array is acquired, and under an adhesive force strengthening condition, an ordered nano-ring array is acquired. The technology of the method is simple, cost is low, and the method can be expanded to a waferscale.

The invention belongs to the field of inorganic luminescent materials. The invention relates to preparation of a calcium ion and europium ion co-doped bismuth oxysulfide nanocrystal and an applicationof the nanocrystal in pH detection. A quantum dot fluorescent probe for pH detection is formed by modifying the surface of a citric acid ligand with 10Ca/6Eu: Bi2O2S nanocrystals, and the molar ratioof the citric acid ligand to the 10Ca/6Eu: Bi2O2S nanocrystals is (2-10): 1. In the process of preparing the nanocrystal, alkaline earth calcium ions are added, so that the nucleation energy barrierof the bismuth oxysulfide nanocrystal is reduced, and the growth of the bismuth oxysulfide nanocrystal is further promoted. On the basis, through surface ligand exchange, the surface of the nanocrystalline is provided with the citric acid ligand. Along with the increase of the pH value, carboxyl in citric acid is gradually ionized, and the electronegativity of the surface of the nanocrystal is gradually reduced, so that the electronic layout on a charge migration band is inhibited, and the fluorescence intensity of Eu<3+> ions is further reduced. The simple fluorescence pH detection method provides a new idea for exploring a novel pH probe.

The invention discloses a preparation method for a polybutylene succinate/graphene-molybdenum-disulfide-like nanocomposite material. The preparation method comprises the following steps: adding molybdenum disulfide powder to mixed liquid of butanediol and water, and centrifugally separating after the room temperature liquid phase ultrasonic treatment; adding a succinic acid to upper deep green liquid obtained by the centrifugal separation, strongly and mechanically stirring until no water is generated in 150-225 DEG C of the temperature under the nitrogen protection, to obtain a terminal hydroxyl prepolymer containing the graphene-molybdenum-disulfide-like; rapidly adding a catalyst to the terminal hydroxyl prepolymer under the stirring condition, and warming to 210-250 DEG C, and vacuumizing to 50-250 Pa, continuously stirring until the obvious pole-climbing occurs, and ending the reaction, to obtain the polybutylene succinate/graphene-molybdenum-disulfide-like nanocomposite material.The composite material is capable of improving the crystallization temperature of the polybutylene succinate, shortening the crystallization time, and refining the crystal grains of the polybutylenesuccinate.

The invention relates to a luminescent material, a preparation method thereof and a foaming product, the foaming material is mainly prepared from poly-4-methyl-1-pentene and a reinforcing agent through a supercritical foaming process, and the particle size of the reinforcing agent is 40-100 nm. The foaming material has excellent impact strength and compression strength.

The invention provides a gas phase magnesium purification method based on a pure iron filter material. The method uses the pure iron filter material to filter magnesium vapor, on one hand, the pure iron does not react with the magnesium vapor, and no new impurities are brought to the system; on the other hand, impurities Al, Mn and iron in the magnesium vapor have special affinity, and stable solid solution can be formed with iron; meanwhile, pure iron can be used as a site for nucleation of certain impurities in the magnesium vapor, so that the nucleation energy barrier can be reduced, the certain impurities can be deposited in advance, and impurities can be removed. The method can be applied to industrial large-scale gas phase magnesium purification, the production efficiency of magnesium purification is improved on the order of magnitude through increasing the temperature, the content of impurities Mn in the magnesium raw material is reduced to 10 ppm or below, the content of Al isreduced to 10 ppm or below, the content of Ca is reduced to 20 ppm or below, and meanwhile, non-metal impurity elements such as F, Cl and S can be removed to obtain the magnesium with the purity of 99.99% or above.

The invention discloses an Sc/Zr modified high-modulus and high-strength aluminum-lithium alloy and a laser forming method thereof, and belongs to the technical field of laser forming. The method comprises the following steps that: firstly, rare earth elements Sc and Zr are added into an aluminum-lithium alloy to obtain modified powder; and due to the addition of the elements Sc and Zr, alloy grains are refined, the alloy strength is improved, the thermal cracking resistance is improved, and the problem that the aluminum-lithium alloy is prone to cracking in the laser forming process is remarkably solved. The invention discloses the laser forming method of the Sc/Zr modified high-modulus and high-strength aluminum-lithium alloy. Laser forming process parameters are suitable for all aluminum lithium alloys with alloy components in a nominal component range. An optimal performance process window is obtained, the aluminum-lithium alloy prepared through adopting the laser forming method is compact in structure and free of hot cracks, and has the excellent performance of high strength and high modulus.

The invention relates to a preparation method and application of a zinc sheet with a surface coating, and the preparation method comprises the following steps: 1) slowly adding laponite powder into a solvent under a stirring condition, and continuously stirring to obtain a uniform dispersion liquid; 2) uniformly coating the surface of a zinc sheet with the dispersion liquid prepared in the step 1) according to a preset thickness; and (3) rapidly transferring the zinc sheet treated in the step (2) to a vacuum drying condition, heating to 60 DEG C, preserving heat, taking out and cooling to obtain the zinc sheet with a surface coating. The preparation conditions are simple, the uniform surface coating for protecting the negative electrode of the zinc ion battery can be obtained only through the steps of mixing, stirring, smearing, drying and the like, harsh reaction conditions are not needed, the cost is low, and the efficiency is high; moreover, the adopted laponite is rich in reserves and low in price, toxic and harmful solvents are not needed in the preparation process, the preparation method is environmentally friendly, and the obtained surface coating is uniform, stable in electrochemical property and good in cycling stability.

The invention discloses a method for preparing alpha-Al2O3 nanoparticles. The method comprises the following steps that 1, water-soluble ferric salt and water-soluble aluminium salt are dissolved in deionized water according to a molar ratio of ferric ions to aluminium ions of 0-1; 2, a (NH4)2.CO3 solution with the concentration of 1-4 mol/L is added into a mixture in the step (1) dropwise, and after sol is generated, dropping adding is stopped immediately; 3, the sol is aged at a room temperature to prepare gel; 4, the gel is placed in an oven for drying to prepare a precursor; 5, the precursor is calcined with a heating rate of 1-3 DEG C/min at 600-850 DEG C to obtain an alpha-Fe2O3/alpha-Al2O3 nanometer compound; 6, acid washing is conducted on the alpha-Fe2O3/alpha-Al2O3 nanometer compound material to remove alpha-Fe2O3 particles to obtain the alpha-Al2O3 nanoparticles. According to the method for preparing the alpha-Al2O3 nanoparticles, the calcination temperature is reduced, energy consumption is reduced, and the operation steps are simple.

The invention belongs to the technical field of lithium batteries, and specifically discloses a composite metal lithium negative electrode and a preparation method and application thereof. The negative electrode comprises a three-dimensional carbon-based current collector with a porous structure, and a metal attached to the surface of the three-dimensional carbon-based current collector and in the internal pores. Lithium, and a protective film covering metal lithium; the protective film includes a lithiophilic metal and a lithium salt, and the lithiophilic metal is a metal that can be reduced and replaced by lithium metal; the composite metal lithium negative electrode is in the first charge and discharge process with the electrolysis The liquid reacts to form a stable solid electrolyte phase interface, and the solid electrolyte phase interface will not decompose during subsequent charge and discharge processes. The three-dimensional carbon-based current collector, lithiophilic metal and lithium salt in the composite metal lithium negative electrode of the invention play the roles of relieving the volume strain of the negative electrode, inducing uniform deposition of lithium and forming a stable SEI film on the surface of the negative electrode, and the preparation method is simple, practical and cost-effective. Low, it is used in metal lithium secondary batteries, which can greatly improve the cycle life of the battery and improve the battery performance.

The invention discloses a co-doped red-light fluorescent light-emitting nanocrystalline material as well as a preparation method and application thereof. According to the nanocrystalline material, under the excitation condition of 254 nm, the luminous intensity of Eu<3+> ions is continuously weakened along with the increase of the concentration of Pb<2+> ions; under the excitation condition of 311nm, the luminous intensity of the Eu<3+> ions is not changed along with the increase of the concentration of the Pb<2+> ions; the ratio of the luminous intensity of the Eu<3+> ions to the concentration of the Pb<2+> ions can be applied to ratio type Pb<2+> ion detection; the ratio type fluorescence detection method is not interfered by external factors and has good accuracy. Under the excitationcondition of 254nm, the luminous intensity of the Eu<3+> ions is continuously weakened along with the increase of the concentration of the Pb<2+> ions, the luminous intensity of the Eu<3+> ions is notchanged along with the increase of the concentration of the Pb<2+> ions under the excitation condition of 311 nm, and the ratio of the luminous intensity of the Eu<3+> ions to the Pb<2+> ion concentration can be applied to ratio-type Pb<2+> ion detection.

The invention provides a conductive polybutylene foaming material and a preparation method thereof. The preparation method provided by the invention comprises the following steps: uniformly mixing the polybutylene resin, the organic nucleating agent, the anti-shrinking agent, the conductive high-molecular polymer and the auxiliary agent, extruding and granulating by an extruder, then molding into a plate by an injection molding machine, and foaming the injection-molded plate by using supercritical fluid in mold pressing foaming equipment, thereby obtaining the high-temperature-resistant and high-pressure-resistant composite material. The obtained foaming material is low in shrinkage rate, small in foam hole size and good in impact property, has electrical conductivity and is a functional polymer foaming material with excellent comprehensive performance.