417 results about "Praseodymium" patented technology

The present invention discloses a medium-high performance neodymium iron boron and a preparation method thereof. Through the master-slave phase double alloy process, the master phase alloy is cerium iron boron with a low total rare earth content, and the slave phase is a neodymium iron boron alloy with a high total rare earth content, avoiding the entry of light rare earths in the master phase into the grain boundaries, while the surplus rare earths in the slave phase enter the grain boundaries and are recombined into rare earth-rich phases. The prepared magnet is processed into a thin magnetic sheet, and a low-melting-point HReM alloy is magnetron sputtered, realizing low-temperature grain boundary diffusion. This alloy improves the grain boundary wettability and also improves the fluidity of the rare earth-rich phase, enabling the cerium-containing neodymium iron boron master and slave phase grains to be quickly isolated during grain boundary diffusion. The low-temperature diffusion avoids the replacement of the diffused heavy rare earths by praseodymium, neodymium, and cerium elements, inhibits the exchange coupling between cerium iron boron grains, and makes the heavy rare earths free in the grain boundaries or interact with the rare earth-rich phase to form a core-shell structure on the surface layer of the master phase grains, enabling the rare earth-rich phase to be continuously and uniformly distributed, effectively enhancing the effectiveness of the grain boundary diffusion of heavy rare earth elements in improving the intrinsic coercivity of the cerium-containing magnet.

The invention belongs to the technical field of catalysts, and relates to a surface-reconstructed heterojunction catalyst and a preparation method and application thereof. The preparation method comprises the following steps: dissolving cobalt salt, ferric salt and praseodymium salt in deionized water, heating and spraying on a carrier to prepare praseodymium-doped ferrocobalt layered double hydroxide; mixing the praseodymium-doped ferrocobalt layered double hydroxide with a phosphorus source, and calcining in an inert atmosphere to prepare praseodymium-doped CoP / Fe2P; and carrying out electrooxidation treatment on the praseodymium doped CoP / Fe2P, so as to prepare the Pr6O11 cluster modified CoFeOOH heterojunction catalyst. Through cooperation of three technologies of spray thermal deposition, phosphating and electrooxidation, stable construction and electrochemical activation of a heterogeneous interface are realized, the corrosion resistance and chlorine evolution resistance competitive capacity of the catalyst in a chlorine-containing alkaline system are remarkably improved, the current density of 100 mA. Cm <-2 > can be achieved only through 223 mV overpotential, and meanwhile, stable operation is performed for 500 h.

The present application relates to the technical field of tungsten alloy materials, and in particular to a tungsten alloy wire, a preparation method therefor, and a use thereof in cutting of a semiconductor material. The tungsten alloy is composed of the following elements in percentage by mass: 0.4-1.1 wt% of L, 0.001-0.25 wt% of Z, and the balance of tungsten and inevitable impurities, wherein L is one or more than two of lanthanum, cerium, praseodymium, neodymium, gadolinium and erbium, and Z comprises oxygen and carbon. The wire diameter of the wire is 20-60 μm, the wire contains linear L or a compound of L along the wire axis direction, and the radial average width D of L or the compound of L is smaller than or equal to 5 nm. According to the present application, the linear L element is doped between tungsten base bodies, and the radial average width of L is controlled to be smaller than or equal to 5 nm, so that the wire has the tensile strength of 5000 MPa or above under the wire diameter of 20-60 μm, and the machining performance of the tungsten alloy wire is enhanced.

The present invention relates to the technical field of tungsten alloy materials, and in particular to a tungsten alloy wire, and a preparation method therefor and a use thereof. The tungsten alloy is composed of the following elements in percentage by mass: 0.45-0.9 wt% of L, 0.05-0.2 wt% of oxygen, and the balance being tungsten and inevitable impurities, wherein L is one or more of lanthanum, cerium, praseodymium, neodymium, gadolinium, and samarium, the wire has a wire diameter of 20-60 μm, in the wire, L or compounds of L exist in the axial direction of the wire in a linear shape, and the average width D of L or the compounds of L in the radial direction is less than or equal to 5 nm. The element L is controlled to be doped between the tungsten base materials in a linear shape, and the average width D of L in the radial direction to be less than or equal to 5 nm, so that cracks and wire breakage caused by second-phase particles in the subsequent pressure machining process are greatly reduced, thereby guaranteeing the mechanical strength of the tungsten alloy wire, and thus the wire has a tensile strength of 5000 MPa or above under a wire diameter of 20-60 μm, and the machining performance of the tungsten alloy wire is enhanced.

The present application provides an entropy-regulated composite dielectric film, which comprises a polymer matrix; and fillers dispersed in the polymer matrix, wherein the fillers comprise Bi 4‑a M 1a Ti (3‑3b) M 2b O 12 , wherein M1 comprises at least one of lanthanum, neodymium, samarium and praseodymium, M2 comprises at least one of zirconium, hafnium and tin, 0 The entropy-regulated composite dielectric film has high temperature resistance, high breakdown strength, high polarization strength, high energy storage density and good stability.

The invention relates to the technical field of lithium ion batteries, in particular to a diaphragm material for a lithium battery and a preparation method of the diaphragm material. Comprising a base film and a modified nano TiO2 coating, the modified nano TiO2 coating is arranged on at least one side surface of the base film, and the modified nano TiO2 coating comprises the following raw materials in parts by weight: 55-80 parts of a modified nano TiO2 composite material, 8-24 parts of a binder and 2.5-7.5 parts of a dispersant; the modified nano TiO2 composite material is prepared by taking cellulose nanocrystals, lanthanum zirconate and rare earth praseodymium as modifiers and nano TiO2 as a raw material, the mass ratio of the cellulose nanocrystal to the lanthanum zirconate to the rare earth praseodymium is (1-5): (2-3): 1. By adding the modified nano TiO2 composite material and introducing nano particles into the diaphragm, a three-dimensional network structure is formed, the liquid absorption property and the ionic conductivity of the diaphragm are improved, and meanwhile, the diaphragm is high in air permeability and relatively good in mechanical property and ionic conductivity.

The invention relates to the field of abrasive materials, in particular to an efficient grinding diamond abrasive material and a preparation process thereof.The efficient grinding diamond abrasive material is prepared by coating diamond micro-powder for multiple times to prepare composite diamond micro-powder, then blending the composite diamond micro-powder with electrolytic copper powder, filler, a wetting agent and modified polyvinyl alcohol to obtain slurry, and conducting freezing-unfreezing gel forming to obtain the efficient grinding diamond abrasive material. The prepared diamond grinding material is good in water resistance and efficient in grinding; the preparation method comprises the following steps: depositing a tungsten coating on the surface of diamond micro-powder, then carrying out vacuum high-temperature treatment to obtain pretreated diamond micro-powder with a tungsten carbide layer growing in situ on the surface, generating a silicon oxide layer on the pretreated diamond micro-powder by using tetraethoxysilane, and then generating praseodymium-doped cerium oxide nanoparticles on the surface of the modified diamond micro-powder by using a homogeneous precipitation method; the preparation method comprises the following steps: carrying out chain extension treatment on a prepolymer generated by polytetrahydrofuran ether glycol and 4, 4 '-dicyclohexylmethane diisocyanate by using a silicon-containing chain extender to obtain a polyurethane prepolymer, and then modifying polyvinyl alcohol by using the polyurethane prepolymer and phenolic resin.

The invention relates to a PVB (polyvinyl butyral) composite film as well as a preparation method and application thereof. The PVB composite film is prepared from the following raw materials in parts by weight: 100 parts of PVB resin, 1-10 parts of nano praseodymium oxide, 1-10 parts of a dispersing agent, 0.01-1 part of a coupling agent and 20-50 parts of a plasticizer. The nano praseodymium oxide is added into the PVB resin, and the infrared absorption band of the PVB composite film is optimized by utilizing the infrared absorption performance, chemical stability and heat-resistant stability of the nano praseodymium oxide, so that infrared radiation can be efficiently blocked, and the excellent heat insulation effect and long-term use stability of the PVB composite film are realized. Furthermore, the nano praseodymium oxide is modified by a coupling agent, so that the dispersion uniformity of the nano praseodymium oxide in the PVB resin and the interface bonding force of the nano praseodymium oxide and the PVB resin are improved, the light transmittance loss of the PVB composite film is reduced, and the mechanical property and the heat insulation property of the composite film are improved.

The invention relates to the technical field of rare earth electrolytic metallurgy, and discloses a praseodymium-neodymium alloy low-temperature electrolysis cell voltage optimization method and system.The method comprises the steps that multi-parameter coupling analysis is conducted on an electrolytic cell low-temperature electrolysis initial parameter set, and key influence factors are obtained; carrying out correlation analysis on the key influence factors by combining fluctuation characteristics of the cell voltage to obtain an influence weight sequence; determining a collaborative adjustment scheme of the polar distance and the current density according to the weight sequence; the cell voltage is synchronously adjusted based on the collaborative adjustment scheme, and accurate control over the two is achieved; the operation parameters of the electrolytic cell are collected and integrated to obtain a feedback parameter set, the feedback parameter set is fed back to a correlation analysis link to optimize the key influence factor identification precision, and finally a cell voltage optimization scheme is obtained. The technology can accurately identify the key influence factors, dynamically adapt to the operation change of the electrolytic cell, improve the stability of the cell voltage, reduce energy consumption and cost, and improve the efficiency of cell voltage optimization. The production efficiency and the product quality are ensured.

The invention relates to the technical field of rare earth permanent magnet materials, in particular to permanent magnet alloy powder, a preparation method thereof, a prepared permanent magnet and a method. Wherein the permanent magnet alloy powder and the permanent magnet alloy comprise the following components: REa (La1-mCems) b-Feba-Mc-Tn-Bd, and RE is at least one of Pr, Nd, Sm, Y, Gd, Tb, Dy, Ho and Yb; m is at least one of Zr, Nb, Mo, Hf, Mn, Ta and W; t is at least one of Cr, V, Si and Ti; wherein 0 < a < = 2.0, 11 < = b < = 13.5, 0 < = c < = 1.5, 6 < = d < = 8.1, 0 < = m < = 1, and 0 < n < = 3.0. According to the permanent magnet alloy powder, lanthanum and cerium are adopted to replace part of precious rare earth elements to prepare the permanent magnet alloy powder, the cost can be greatly reduced, the oxidation resistance is improved and the flammability is reduced through a small amount of refractory metal M and antioxidant reinforced metal T matched elements, and the problem that a pure praseodymium neodymium-lanthanum cerium / cerium-based iron boron material is poor in temperature resistance and oxidation resistance is solved.

The invention discloses porous chlorine dioxide slow-release preservative paper and a preparation method thereof.The porous chlorine dioxide slow-release preservative paper comprises a paper base, a porous carrier is fixed to the paper base through oxidized starch glue, and sodium chlorite, an activating agent and a stabilizing agent are loaded on the porous carrier; the porous carrier is one of aluminum oxide, titanium oxide, cobalt oxide, zinc oxide, copper oxide, iron oxide, cerium oxide, zirconium oxide, nickel oxide, manganese oxide, praseodymium oxide and lanthanum oxide with a porous structure. The slow release of chlorine dioxide can be stably and effectively realized, the release period of chlorine dioxide is prolonged, and long-acting stable sterilization and disinfection effects are realized.

The invention relates to the technical field of rare earth metal separation, and particularly discloses a praseodymium neodymium oxide separation and purification process and a regeneration system. The process comprises the following steps: after H2S is subjected to impurity removal and filtration, carrying out multi-stage counter-current extraction by adopting a P507 / TRPO synergistic extraction organic phase, carrying out graded reverse extraction on praseodymium by HCl, and carrying out reverse extraction on neodymium by HNO3; the regeneration system comprises a wastewater treatment unit and an organic phase regeneration unit, wastewater is recycled through neutralization precipitation, precision filtration and reverse osmosis, and an organic phase is subjected to alkali washing, acid activation and 4A molecular sieve dehydration circulation. The praseodymium-neodymium separation coefficient reaches 2.0-2.2 through synergistic extraction, and the stage number is reduced by 40%; the double regeneration systems reduce the organic phase loss to be less than or equal to 2% and the wastewater reuse rate to be greater than or equal to 92%; the purity of the prepared neodymium oxide is greater than or equal to 99.99% and Fe is less than or equal to 10ppm. According to the method, the extraction efficiency is remarkably improved, the service life of an organic phase is multiplied, the product purity breaks through the limit, near-zero wastewater discharge is closed, the whole process stability is guaranteed, and the resource utilization rate is maximized.

The invention relates to the technical field of fluorescence sensing, in particular to a praseodymium (III) metal organic framework crystalline material and a preparation method and application thereof. According to the praseodymium (III) metal organic framework crystalline state material, Pr (III) is used as a central metal ion and forms eight coordination with eight oxygen atoms of six (4-CPCA) 2-ligands. And adjacent Pr (III) are connected through 4-CPCA < 2-> bridging to form a one-dimensional annular chain. And the one-dimensional chains are further bridged and topologically connected through a (4-CPCA) 2-ligand to form a three-dimensional structure. The praseodymium (III) metal organic framework crystalline material has good fluorescent property and stability, and can be applied to the field of fluorescence sensing.

The present invention relates to the technical field of tungsten alloy materials, and particularly relates to a tungsten alloy wire and a preparation method and application thereof. In terms of mass fraction, the components of the tungsten alloy include: 0.3-0.75 wt% of element L, 0.001-0.18% of oxygen element, and the balance is tungsten element and inevitable impurities; wherein, L is one or more of lanthanum, cerium, praseodymium, neodymium, gadolinium, and erbium; the wire diameter of the wire is 0.3-0.6 mm; and in the wire, the average radial width of the tungsten fibers is ≤0.4 μm; the number of cracks per 100 meters of flaw detection on the surface of the wire is ≤5. The tungsten alloy wire provided by the present invention has finer internal tungsten fibers, the tungsten fibers are effectively strengthened and the density is improved, and the flaw detection number on the surface of the tungsten alloy wire is small; the effective strengthening of the internal tungsten fibers and the improvement of the density enable the medium-temperature breaking force, medium-temperature creep resistance and winding performance of the wire to be improved; therefore, when it is used as a tungsten wire rope for pulling single crystal silicon, both the reliability and the service life are improved.

The invention discloses a neodymium-iron-gallium double-alloy heavy-rare-earth-free 54H sintered neodymium-iron-boron magnet and a preparation method thereof, and relates to the technical field of neodymium-iron-boron magnet preparation, and the neodymium-iron-gallium double-alloy heavy-rare-earth-free 54H sintered neodymium-iron-boron magnet comprises the following preparation raw materials: 170-175 kg of PrNd (praseodymium-neodymium alloy), 25-30 kg of BFe (iron white copper), 1-5 kg of Co (cobalt), 0.1-2 kg of Cu (copper), 1-5 kg of Zr (zirconium), 0.1-1 kg of Ga (gallium) and 380-420 kg of Fe (iron). According to the neodymium-iron-gallium double-alloy heavy-rare-earth-free 54H sintered neodymium-iron-boron magnet and the preparation method thereof, the 54H sintered neodymium-iron-boron magnet is prepared through a double-alloy technology with neodymium, iron and gallium as auxiliary alloy without adding dysprosium, terbium and other scarce type heavy rare earth elements, and performance optimization and cost optimization of the neodymium-iron-gallium double-alloy heavy-rare-earth-free 54H sintered neodymium-iron-boron magnet are achieved.

The invention discloses a cerium-zirconium-based high-entropy oxide as well as a preparation method and application thereof. According to the cerium-zirconium-based high-entropy oxide, cerium and zirconium serve as main bodies, and meanwhile rare earth elements (lanthanum, praseodymium, neodymium and samarium) and transition metal elements (manganese, iron, cobalt, nickel, copper and zinc) are introduced to form a high-entropy solid solution with the equal molar ratio and containing 3-8 kinds of metal. In the cerium-zirconium-based high-entropy oxide, the cerium element and the zirconium element respectively account for 20%-40% of the total amount, and the other elements are respectively 10%-30% in an equimolar ratio. The cerium-zirconium-based high-entropy oxide catalyst prepared by the invention has excellent oxygen storage and release capacity and CO oxidation capacity, and the CO complete conversion temperature is 181 DEG C. The method adopts a simple coprecipitation process, is mild in condition and low in cost, and is suitable for large-scale application in the field of tail gas purification.

The invention discloses a high-cerium neodymium-iron-boron magnet and a preparation method thereof, and relates to the field of rare earth permanent magnet materials. The high-cerium neodymium-iron-boron magnet is prepared through a double-main-phase method, in the preparation process, the surface of cerium main-phase magnetic powder is sequentially coated with a praseodymium diffusion layer and a heavy rare earth-oxide barrier layer through a magnetron sputtering method, the diffusion direction of praseodymium and heavy rare earth elements is limited, and excessive mutual diffusion of neodymium and cerium is restrained; in addition, grain boundary diffusion heavy rare earth elements are guided to penetrate into the magnet, a good modification effect is achieved with a small amount of added elements, and the magnetic performance of the high-cerium neodymium-iron-boron magnet is greatly improved.

The invention relates to the technical field of neodymium-iron-boron magnet production, in particular to a sintered neodymium-iron-boron magnet for preparing lanthanum-cerium-yttrium and a method of the sintered neodymium-iron-boron magnet. In the invention, the cerium element is used for replacing a praseodymium-neodymium alloy, meanwhile, the lanthanum and yttrium elements are introduced according to the proportion to generate a synergistic effect to regulate and control the structure of the high-cerium-content sintered neodymium-iron-boron magnet, the yttrium element is used for inhibiting main phase grain coarsening and improving the coercive force, and the lanthanum and yttrium elements can promote the flow of a rare earth-rich liquid phase in the sintering process and improve the diffusivity, so that the high-cerium-content sintered neodymium-iron-boron magnet is obtained. The density is improved.

The invention discloses a rare earth metal electrolytic reduction method based on a high-frequency switching power supply, and relates to the technical field of rare earth metal electrolytic reduction, and the method comprises the following steps: firstly, in a praseodymium-neodymium electro-deposition process, parameter data in the praseodymium-neodymium electro-deposition process is accurately obtained in real time by using an advanced sensor and detection equipment; and accurate, comprehensive and real-time data support is provided for subsequent intelligent analysis. According to the invention, the problems of stress accumulation, crack propagation and coating stripping caused by fixed preset intermittent closing time in high-current density electrodeposition are solved. Intelligent optimization is realized through real-time data acquisition, deep learning evaluation and dynamic pulse current regulation and control. And when the stress rise is detected, the system adaptively prolongs the intermittent closing time, and reduces the pulse peak current, so that the deposition rate is optimized, and the uniformity and compactness of a plating layer are improved. The method improves the mechanical strength and corrosion resistance of the coating, prolongs the service life of equipment, reduces the energy consumption, and improves the process stability and consistency.

The invention relates to the technical field of fuel cell new materials and new energy, in particular to an A-site high-entropy perovskite cathode material and a preparation method thereof. According to the technical scheme, the material comprises the following raw materials: Pr (NO3) 3.6 H2O, La (NO3) 3.6 H2O, Co (NO3) 2.6 H2O, CaCO3, BaCO3, SrCO3 and citric acid. The molar ratio of the praseodymium ions to the lanthanum ions to the cobalt ions to the calcium ions to the barium ions to the strontium ions to the citric acid is 1: (1-2). According to the invention, the A site of the perovskite material is doped with a plurality of elements, a rapid quenching preparation process is combined, the oxygen vacancy concentration and the proton conduction path can be optimized, the ORR activity and the conductivity can be improved, and excellent electrochemical performance and thermal stability can be shown through the synergistic effect of the plurality of elements and structural regulation and control, so that the performance of the cell can be improved.

The invention relates to cerium dioxide and a preparation method and application thereof, and the preparation method of the hexagonal cerium dioxide comprises the following steps: (1) carrying out first mixing on cerium salt, doped metal salt, a solvent, inorganic acid and organic acid to obtain a first mixture; the doped metal salt comprises praseodymium salt and / or neodymium salt; (2) under a hydrothermal condition, carrying out second mixing on the first mixture, ammonia water and ammonium salt to obtain a second mixture with the pH value of 3.5-6, and carrying out sol-gel reaction to obtain hexagonal cerium dioxide sol; and (3) carrying out post-treatment on the hexagonal cerium dioxide sol to obtain the hexagonal cerium dioxide. According to the preparation method of the hexagonal cerium dioxide, provided by the invention, a mixing process and a reaction process of cerium salt and specific raw materials are designed, so that the hexagonal cerium dioxide with regular particle shape, good size uniformity and high purity and crystallinity is obtained.

The invention discloses a preparation method of a sintered neodymium-iron-boron magnet without heavy rare earth, Pr-Fe-B-M alloy is used as an auxiliary phase alloy, LRe-Fe-B-M alloy is used as a main phase alloy, the auxiliary phase alloy is used for preparing a magnet matrix and performing grain boundary diffusion at the same time, the magnet without heavy rare earth is prepared, praseodymium element is non-uniformly distributed in the magnet, and rare earth element is not uniformly distributed in the magnet. The Pr content of part of the main phase is higher than the overall average content, the crystal boundary praseodymium content is higher than the overall average content, and the magnet surface praseodymium content is higher than the overall average content. The coercive force and the temperature stability of the magnet are improved, the magnet can still keep excellent magnetic performance under the condition that Dy and Tb are not contained, heavy rare earth elements such as Dy and Tb which are scarce in resource and high in price are prevented from being used, the high performance of the magnet is guaranteed, the production cost is reduced, and the resource utilization efficiency is improved.

An exhaust gas purification catalyst (10) contains a refractory three-dimensional structure (20), a second catalyst layer (31) containing palladium and rhodium, and a first catalyst layer (32) containing palladium positioned between the refractory three-dimensional structure (20) and the second catalyst layer (31), in which the first catalyst layer (32) or the second catalyst layer (31) further contains a Zr—Pr composite oxide that is a composite oxide of zirconium and praseodymium. A proportion of a mass of praseodymium oxide contained in the Zr—Pr composite oxide relative to a total mass of zirconium oxide and praseodymium oxide contained in the Zr—Pr composite oxide may be 11% or more and 90% or less.

The application discloses porous chlorine dioxide slow-release preservative paper and a preparation method thereof. The paper comprises a paper base, a porous carrier is fixed on the paper base through oxidized starch glue, sodium chlorite, an activator and a stabilizer are loaded on the porous carrier, and the porous carrier is one of porous structures of aluminum oxide, titanium oxide, cobalt oxide, zinc oxide, copper oxide, iron oxide, cerium oxide, zirconium oxide, nickel oxide, manganese oxide, praseodymium oxide and lanthanum oxide. The application can stably and effectively realize slow release of chlorine dioxide, prolong the release period of chlorine dioxide, and realize long-acting and stable sterilization and disinfection.

The invention belongs to the technical field of rare earth permanent magnet materials, and relates to a multi-component rare earth alloy diffusion source for improving the coercive force of a high-abundance neodymium-cerium-iron-boron magnet. The invention discloses a multi-component rare earth alloy diffusion source for improving the coercive force of a high-abundance neodymium-cerium-iron-boron magnet. The multi-component rare earth alloy diffusion source comprises rare earth elements and non-rare earth elements, the rare earth element is one or two of praseodymium element and holmium element; the non-rare earth element is a combination of an aluminum element and a copper element; the mass percent of rare earth elements in the multi-component rare earth alloy diffusion source is 80-95%, and the mass percent of non-rare earth elements in the multi-component rare earth alloy diffusion source is 5-20%. The invention further discloses a method for improving the coercive force of the high-abundance neodymium-cerium-iron-boron magnet and the prepared high-performance high-abundance neodymium-cerium-iron-boron magnet. The low-cost heavy rare earth element Ho is adopted as a diffusion source component, a Ho-rich (RE, Ho) 2Fe14B phase with a high magnetocrystalline anisotropy field is formed on the surface layer of main phase crystal grains, and the coercive force of the high-abundance neodymium-cerium-iron-boron magnet is improved.

The invention relates to the technical field of functional composite color-changing materials, in particular to a dynamic color-changing flexible composite material and a preparation method and application thereof. The flexible composite material is prepared from the following raw materials: photochromic powder, a flexible film matrix, low-viscosity silicone oil and a curing agent, the chemical general formula of the photochromic powder is (Li < 0.1 > Na < 0.4 > Bi < 0.5 >) < 0.95-x > Bi < 2 > Pr < x > Y < 0.05 > Nb < 2 > O < 9 >, wherein x ranges from 0.001 to 0.05. According to the flexible composite material provided by the invention, inorganic photochromic powder doped with rare earth elements is introduced into a PDMS / low-viscosity silicone oil elastomer matrix, and the composite ratio of the photochromic powder to the flexible film matrix and the doping content of rare earth ions praseodymium in the photochromic powder are regulated and controlled; the real-time, accurate and reversible regulation and control of the optical characteristic color of the material are realized by virtue of photostimulation, and a brand new thought is provided for preparing an optical stealth material.

The invention discloses a ruthenium-based rare earth composite catalyst and a preparation method and application thereof, the composite catalyst is formed by loading alloy particles of Ru metal and rare earth metal on carboxyl modified lignin derived mesoporous carbon, the molecular formula of the composite catalyst is RuxREy-CLC, x is equal to 0.5-1, y is equal to 0.01-0.1, and RE is any one of neodymium, cerium, lanthanum, samarium, gadolinium, erbium, dysprosium and praseodymium; the catalyst is obtained by coordinating ruthenium ions, rare earth metal ions and carboxyl modified lignin and then carbonizing. According to the ruthenium-based rare earth composite catalyst, more catalytic active sites can be provided through alloy nanoparticle ultra-fining and high dispersion, OH * strong adsorption poisoning is remarkably weakened through introduction of rare earth metal, the excellent alkaline hydrogen evolution reaction electrocatalytic activity is shown, the catalytic stability is improved, and the catalytic activity of the catalyst is improved. The comprehensive performance is obviously superior to that of similar and commercial catalysts, and the catalyst has considerable energy application potential.

A method for producing a coated chromium-containing component includes providing a coating mixture of a solvent and a source of praseodymium and / or a source of terbium, contacting the surface of the component with the coating mixture, optionally drying, and heating the component in an oxidising atmosphere at a temperature of 450° C. or higher. Examples include coated components for a device, and electrochemical devices with coated components, the components having a surface coating including at least one layer that includes a praseodymium material and / or terbium material. The method produces coatings that reduce chromium evaporation and are useful as barriers on a chromium-containing components.

The invention provides a layered-perovskite biphase potassium ion battery positive electrode material as well as a preparation method and application thereof, and belongs to the field of new energy materials. The preparation method of the material comprises the following steps: S1, weighing a proper amount of a potassium source, a manganese source and a praseodymium (or lanthanum and gadolinium) source in a ball milling tank; s2, ethanol is added for ball milling treatment, and a mixture is obtained; s3, drying the mixture; s4, the obtained dried product is subjected to heat treatment, the heat treatment temperature is 850-900 DEG C, the heat treatment time is 12-15 h, then the dried product is cooled to the room temperature, and a black product is obtained; and S5, grinding, sieving and drying the obtained product to obtain the positive electrode material of the potassium ion battery. According to the preparation method, a special sintering atmosphere is not needed, the layered-perovskite double-phase positive electrode material can be obtained only through one-time calcination, and the prepared positive electrode material has better circulation and rate performance compared with a layered single-phase positive electrode material.

The utility model relates to the technical field of praseodymium neodymium oxide processing, in particular to a firing mechanism for praseodymium neodymium oxide processing, which comprises a base, the upper end face of the base is fixedly connected with a heat insulation shell, a plurality of first firing cylinders and second firing cylinders which are distributed in a staggered manner are respectively arranged in the heat insulation shell, the three first firing cylinders rotate clockwise, and the three second firing cylinders rotate clockwise. The two second firing barrels rotate anticlockwise, praseodymium neodymium oxide is brought to the upper end of the interior of the first firing barrel through a plurality of baffles and then slips off from the baffles, the praseodymium neodymium oxide is scattered and falls into the second firing barrel on the left side, then the praseodymium neodymium oxide is scattered again through the baffles in the second firing barrel on the left side, the praseodymium neodymium oxide is evenly heated, and the praseodymium neodymium oxide is evenly fired. Meanwhile, the praseodymium-neodymium oxide is moved into the first firing barrel on the right side through mutual cooperation of the three first firing barrels and the two second firing barrels and then discharged through a discharging pipe, and then the praseodymium-neodymium oxide is continuously fired, so that the working efficiency is improved.