189 results about "Lanthanoid Series Elements" patented technology

The invention discloses a blue-and-white glaze and a preparation method and application thereof, and belongs to the technical field of inorganic non-metallic materials (ceramics), the blue-and-white glaze comprises quartz, feldspar, limestone, plant ash and other basic raw materials, zinc oxide, aluminum oxide, lanthanum oxide, cerium oxide and other rare earth elements, and a modified organic additive is introduced. Compared with the prior art, the blue-and-white glaze shows excellent stability in the drying and firing process, the phenomena of cracking and glaze stripping are effectively reduced, the friction coefficient after firing is low, the breaking strength and the breaking modulus are high, the glossiness and transparency of a glaze surface are remarkably improved, and the blue-and-white glaze has important application value.

The invention relates to the field of ceramic materials, in particular to a ceramic material and a preparation method and application thereof in piezoelectrics, the chemical structural general formula of the ceramic material is as follows: (1-alpha-beta) (Ba1-xMx) [Ti1-y (W1 / 2Cu1 / 2) y] O3-alpha Bi (Sb1 / 3Ln2 / 3) O3-beta Sr2Fe1-zAlzMoO6, M is an alkaline earth metal element; ln is a lanthanide rare earth element; x is equal to 0.12, y is equal to 0.04, z is equal to 0.2, alpha is larger than or equal to 0.01 and smaller than or equal to 0.1, beta is larger than 0 and smaller than or equal to 0.05, and the ceramic material is good in compactness and excellent in piezoelectric performance and can meet the application requirements of piezoelectric ceramic sensors, piezoelectric ceramic transducers and other devices.

The invention discloses a high-capacity lithium iron phosphate positive electrode material and a preparation method thereof, and belongs to the technical field of lithium ion batteries, the lithium iron phosphate positive electrode material is compounded with a perovskite structure ion conductor; the structural formula of the perovskite structure ion conductor is AxB1-xO2-delta, and x is more than or equal to 0.2 and less than or equal to 0.8; wherein A is a rare earth element, and the rare earth element is any one of lanthanum, cerium, praseodymium, neodymium, samarium and gadolinium; b is a transition metal element, and the transition metal element is any one of chromium, manganese, iron, cobalt, nickel, copper and zinc. The perovskite structure ion conductor can provide more moving space for lithium ions, the lithium ion diffusion rate and capacity of the positive electrode material can be improved due to the high ion conductivity and lithium ion storage capacity of the perovskite structure ion conductor, the rare earth atoms can provide an additional migration channel for the lithium ions, the transition metal atoms can provide an additional electron conduction path, and the lithium ion diffusion rate and capacity of the positive electrode material can be improved. Therefore, the transmission rates of lithium ions and free electrons are matched, and the cycle performance is improved.

The invention relates to the technical field of alloys, and discloses a high-strength silver-copper alloy and a preparation method thereof. The acidified carbon nanotubes are subjected to functional modification, methylbenzene-2, 4-diisocyanate reacts with surface active groups of the methylbenzene-2, 4-diisocyanate to introduce-NCO groups, then through hydroxyl reaction of-NCO and 4-hydroxyphthalic acid, a plurality of carboxyl groups are grafted on the surfaces of the carbon nanotubes, the carboxyl groups can firmly adsorb lanthanum nitrate through a coordination effect, and meanwhile, the carboxyl groups can also adsorb lanthanum nitrate through a coordination effect. The rare earth elements are prevented from being separated from the raw materials in the ball milling process, uniform distribution is ensured, the agglomeration tendency of the carbon nanotubes can be reduced, and the dispersity of the carbon nanotubes in the silver-copper alloy is improved; the carbon nanotubes have extremely high axial strength and excellent conductivity, the mechanical and electrical properties of the alloy material can be enhanced through load transfer and a conductive network effect, rare earth lanthanum is segregated at a grain boundary to form a pinning effect to refine grains, the alloy strength is further improved, and finally collaborative improvement of the strength and the conductivity of the silver-copper alloy is achieved.

The invention relates to the field of material science and mechanical engineering, in particular to a high-strength aluminum-magnesium-silicon material bolt for a new energy automobile and a preparation method of the high-strength aluminum-magnesium-silicon material bolt. The bolt is made of an aluminum-magnesium-silicon alloy, and the alloy contains magnesium, silicon, manganese, iron, chromium, titanium, scandium, rare earth elements and the balance of aluminum. By optimizing the proportion of rare earth elements (yttrium, lanthanum and cerium) and scandium, grains are effectively refined, the tensile strength, the yield strength and the ductility are improved, and meanwhile the corrosion resistance and the fatigue resistance are enhanced. The preparation method comprises the steps that vacuum melting is combined with the ultrasonic-assisted technology, alloy elements are evenly distributed, and then the material structure is optimized through solution treatment at the temperature of 540 DEG C for 1.5 h and aging treatment at the temperature of 160 DEG C for 8 h. And the surface of the bolt is subjected to anodic oxidation and coated with a composite coating containing silicon dioxide nanoparticles, so that the wear resistance and the corrosion resistance are improved. Through verification, the bolt has the excellent performance that the tensile strength is larger than or equal to 490 MPa, the yield strength is larger than or equal to 440 MPa, the ductility is larger than or equal to 8.5%, and the salt spray test time is larger than or equal to 1500 hours, and the fastening requirement of the new energy automobile under the complex working condition is met.

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 an anti-corrosion magnesium alloy and a preparation method and a micro-arc oxidation treatment process thereof, relates to the technical field of magnesium alloys, and solves the problem of poor corrosion resistance of magnesium alloys in the prior art. The anti-corrosion magnesium alloy prepared by the method comprises the following chemical components in percentage by mass: 4-8 wt% of aluminum, 2-5 wt% of lanthanum, 1-3 wt% of samarium, 0.5-1.0 wt% of gadolinium, 0.3-0.6 wt% of yttrium, 0.2-0.5 wt% of manganese, magnesium and inevitable impurities, wherein the total mass fraction of the inevitable impurities is less than 0.03%. The anti-corrosion magnesium alloy is prepared by introducing rare earth elements (lanthanum, samarium, gadolinium and yttrium), the micro-arc oxidation ceramic film layer is prepared on the surface of the anti-corrosion magnesium alloy by adopting a low-voltage, low-duty-ratio and low-concentration electrolyte micro-arc oxidation treatment process, the electrochemical corrosion reaction is effectively inhibited, the corrosion resistance of the alloy is improved, the cost is low, and the application range is wide. Good industrial application prospects are realized.

The invention discloses a catalyst for preparing trichlorosilane and a catalytic preparation method of trichlorosilane. The catalyst is prepared from the following components in percentage by mass: weighed copper nitrate, zinc nitrate, aluminum nitrate, lanthanum nitrate and the balance of a carrier, the preparation method comprises the following specific steps: S1, filling a catalyst; S2, purifying raw material gas; S3, reacting; and S4, separating and purifying a product, namely discharging a reacted gas product from an outlet of a reactor, and condensing through a condenser. In the prepared catalyst, the activity and selectivity of the catalyst are remarkably improved through the synergistic effect of the copper-zinc-aluminum composite oxide and the rare earth element lanthanum, the electronic structure and the surface acid-base property of the catalyst can be adjusted through doping of lanthanum, the reaction of silicon powder and hydrogen chloride is promoted, meanwhile, side reactions are inhibited, and the service life of the catalyst is prolonged. And the yield of trichlorosilane is improved.

The invention provides a rare earth silicon germanate scintillating material and a preparation method and application thereof, in particular to a rare earth silicon germanate scintillating material with high thermal stability and strong radiation resistance and a preparation method and application thereof, the general formula of the rare earth silicon germanate scintillating material with high thermal stability and strong radiation resistance is RE2 (1-x-delta / 2) Ce2xGedeltaSi (1-y + delta) Gey-deltaOz, in the formula, 0 lt; x is more than or equal to 0.05, y is more than or equal to 0.15 and less than or equal to 0.5, delta is more than or equal to 0 and less than or equal to 10 <-4 >, z is more than or equal to 4.95 and less than or equal to 5.05, RE represents a rare earth element, and the rare earth element is selected from at least one of lanthanum (La), lutetium (Lu), yttrium (Y) and gadolinium (Gd). The rare earth silicon germanate scintillating material provided by the invention has the characteristics of strong radiation damage resistance, high scintillation light output, low afterglow and the like while greatly improving the thermal stability, and can be used in occasions with extremely high requirements on the thermal stability or radiation resistance of the material, such as high-energy physical experiments, nuclear medicine imaging, oil exploration wells and the like.

The invention discloses a preparation process of a rare earth precipitation resistant electrophoretic coating for an automobile body. The preparation process comprises the following steps: S1, preparing a stable solution; s2, preparing a rare earth chelating solution; adding lanthanum lactate into the stable solution for multiple times, and adding ammonium ceric sulfate for multiple times after the lanthanum lactate is completely dissolved; s3, preparing a resin base solution; s4, preparing mixed slurry; s5, adding a solvent and an auxiliary agent; a five-membered ring chelate with thermodynamic stability is formed by carboxyl, hydroxyl and rare earth elements in sodium citrate, rare earth ions can be tightly wrapped through strong coordination bonds, namely, empty orbits of the rare earth ions and lone pair electrons of a chelating agent form coordination bonds, so that the rare earth ions cannot be dissociated in a system, and the rare earth ions are prevented from being dissociated in the system. And a path of generating hydroxide precipitates by free rare earth ions is thoroughly blocked, so that rare earth elements are effectively ensured to be uniformly distributed in the electrophoretic paint, and the surface of a raw material treated by a subsequent electrophoresis process is more uniform.

The invention relates to the technical field of metallurgy and chemical industry, in particular to a silicon-manganese alloy smelting method which comprises the following steps of raw material pretreatment, gradient reduction smelting, tapping and refining and flue gas slag cooperative treatment. In the silicon-manganese alloy smelting process, lanthanum-cerium oxide in the rare earth composite material reacts with impurities such as sulfur, phosphorus and oxygen in a melt at high temperature to form a high-melting-point compound which is separated along with slag, the impurity content is effectively reduced, meanwhile, rare earth elements are segregated at the grain boundary, atomic diffusion migration is inhibited, the alloy grain size is remarkably refined, and the alloy yield is improved. And the rare earth composite material optimizes the alloy solidification structure through the double effects of chemical purification and physical modification, the problems of impurity segregation and insufficient toughness in the traditional silicon-manganese alloy smelting process are solved, and the mechanical property of the silicon-manganese alloy is remarkably improved.

The invention belongs to the technical field of aluminum alloy grain refiners, and particularly relates to a grain refiner and a preparation method and application thereof.The preparation method of the grain refiner comprises the following steps that S1, aluminum powder, vanadium powder, boron powder and lanthanum powder are obtained; s2, after uniform mixing, vacuum ball milling is performed to obtain first powder, and the first powder is sieved to obtain second powder; s3, pressing the second powder to obtain a metal cake; s4, sintering the metal cake in an inert gas atmosphere to obtain a grain refiner; the Al-V-B-La refiner is prepared through a sintering method, the distribution condition of a second phase in the grain refiner and the grain refining effect of the grain refiner are improved through the rare earth element La, the VB2 phase in the grain refiner with the La element added is more uniform in distribution, smaller in size and larger in number density, more second phases can play a role in refining, and the grain refining effect of the grain refiner is improved. And the problem that the refining efficiency is low due to the Si poisoning problem of a traditional grain refiner is solved, and therefore the better aluminum alloy grain refining effect is achieved.

The invention provides a magnesium alloy, a magnesium alloy shell and electronic equipment. The magnesium alloy comprises the following components in percentage by weight: 2.5%-4.5% of aluminum, 0.5%-1.0% of zinc, 0.2%-0.8% of manganese, 0.01%-1.0% of titanium, 0.01%-0.5% of antimony and the balance of magnesium, additive elements and inevitable impurities, the additive element is a lanthanum-cerium mixed element, and the total weight percentage of the lanthanum element and the cerium element is 0.5%-1.5%. The magnesium alloy can be applied to a magnesium alloy shell, a small amount of low-price mixed rare earth (La / Ce) is added into an alloy of an Mg-Al-Zn system with the low Al content, the refining effect of trace Ti and Sb elements is matched, the corrosion resistance of the magnesium alloy can be greatly improved, meanwhile, the use amount of the rare earth element and the aluminum element is reduced, the manufacturing cost is reduced, and the service life of the magnesium alloy is prolonged. The method is suitable for mass production of electronic products.

The invention discloses a high-strength rare earth aluminum alloy material, a preparation method and application. The aluminum alloy material comprises, by weight, 0.2%-1.2% of Si, 0.2%-1.5% of Mg, 0.1%-0.2% of Cu, 0.1%-1.0% of Zn, 0.06%-1.0% of Mn, 0.06%-0.6% of Cr, 0.0.08%-0.3% of V, 0.03%-0.3% of Ag, 0.06%-0.4% of Ti, 0.01%-0.35% of Zr, 0.01%-0.35% of Hf, smaller than or equal to 0.20% of Fe, 0.03%-0.6% of La, 0.03%-0.4% of Yb, 0.03%-0.8% of Sm, smaller than or equal to 0.04% of other inevitable single impurity elements, smaller than or equal to 0.15% of the total amount of the impurity elements and the balance aluminum. In order to solve the problems of low room temperature strength, insufficient plasticity, poor thermal stability and the like of the existing 6000 series aluminum alloy, alloy elements are reasonably optimized, a proper amount of rare earth elements lanthanum, samarium and ytterbium are added, and a high-performance aluminum alloy material is developed and used for bolt manufacturing, so that the bolt has high room temperature strength, plasticity and thermal stability, and the service life of the bolt is prolonged. And the requirements of various fields for high-performance aluminum alloy bolts are met.

The present invention relates to a method for preparing a catalyst composition and a method for preparing a conjugated diene-based polymer using the catalyst composition prepared thereby, the preparation method of the catalyst composition continuously prepares a catalyst composition having improved catalyst activity by pretreating a hydrogen bond type lanthanide rare earth element compound and / or an oligomer type lanthanide rare earth element compound that causes deterioration of catalyst activity.

The invention belongs to the technical field of catalyst preparation, and relates to efficient preparation of clean energy, in particular to an energy-saving hydrogen production system using a binary alloy catalyst formed by rare earth elements under the assistance of ethanol. The preparation method comprises the following steps: uniformly mixing metal precursors of palladium and lanthanum, molybdenum hexacarbonyl and an n-caprylic acid solvent by adopting a wet chemical synthesis method, carrying out an oil bath reaction for a period of time, separating precipitates, and sequentially washing and drying to obtain the binary alloy catalyst. The improvement and promotion effects of ethanol on a traditional water electrolysis hydrogen production system are researched in an H-shaped electrolytic tank, and it is proved that ethanol-assisted hydrogen production is an efficient and energy-saving hydrogen production mode. The preparation method of the catalyst is simple, has few steps and is simple and convenient to operate. Compared with a Pd metal alkene catalyst and commercial Pd black, the catalyst provided by the invention has more excellent catalytic activity and stability. The hydrogen production mode is more efficient, and energy consumption is greatly reduced.

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 relates to an A-site high-entropy double perovskite anode material and a preparation method and application thereof. The chemical general formula of the anode material is (Ln < 1 > < 0.2 > Ln < 2 > < 0.2 > Ln < 3 > < 0.2 > Ln < 4 > < 0.2 > Ln < 5 > < 0.2 >) A 'B2O5 + delta (wherein delta is greater than or equal to 0 and less than or equal to 1). Wherein Ln1 to Ln5 are five different lanthanide rare earth elements and jointly occupy the A site, and the A site elements are any five of Sm, Pr, Nd, La, Gd, Eu, Er, Dy, Te, Yb, Y and Sc; the A'site is composed of any two elements of Ba, Sr and Ca; and the B site is Co. According to the invention, the double perovskite structure can be effectively stabilized, the number of catalytic active sites of an OER reaction is increased, the TEC of a cathode is effectively reduced, the electro-catalysis ORR reaction activity is increased, the performance of hydrogen production by electrolysis of water of a single cell is improved, and the output stability of the cell is effectively enhanced.

The present invention relates to a method for continuously preparing a catalyst composition for preparing a catalyst composition having improved catalyst activity by pretreating a hydrogen-bonded lanthanide rare earth element compound and / or an oligomer type of a lanthanide rare earth element compound, which induce the deterioration of the catalyst activity, and a method for preparing a conjugated diene-based polymer using the catalyst composition prepared thereby.

The invention provides a modified charcoal-based slow-release rare earth lanthanum soil conditioner and a preparation method thereof, and relates to the technical field of soil conditioners, the saline-alkali soil conditioner is used for reducing soil salinity and alkalinity, fixing heavy metals in soil, improving soil structure and slowly releasing rare earth elements into soil; the preparation method comprises the following steps: 1, preparing a rare earth lanthanum compound; modifying the biochar; a phosphate; dewatering the river sludge; an organic complexing agent; step 2, dissolving a rare earth lanthanum compound and an organic complexing agent in deionized water, and reacting to generate a complex solution; step 3, preparing modified biological carbon; step 4, loading lanthanum; and step 5, mixing the matrix to obtain the saline-alkali soil conditioner. Lanthanum nitrate and sodium citrate are converted into a complex solution, the lanthanum citrate complex has good stability, lanthanum can be effectively fixed in the solution in the form of the complex, the lanthanum is prevented from precipitating or losing in the subsequent treatment process, and the slow release effect of lanthanum is achieved.

The present invention relates to: a catalyst composition preparation method for continuously preparing a catalyst composition with improved catalytic activity, the method pre-treating a hydrogen-bonded lanthanide rare earth element compound and / or an oligomeric form of a lanthanide rare earth element compound which causes a decrease in catalytic activity; and a conjugated diene-based polymer preparation method using the catalyst composition prepared the method.

The invention discloses a high-specific-strength ceramic aluminum alloy and a preparation method thereof, and relates to the technical field of high-specific-strength ceramic aluminum alloys, and the high-specific-strength ceramic aluminum alloy comprises the following components in percentage by weight: 5-15% of nano-scale silicon carbide, aluminum nitride, aluminum oxide and other composite ceramic particles, and the balance of aluminum alloy containing magnesium, zinc and copper and impurities. 0.1%-1% of rare earth elements such as lanthanum, cerium and yttrium and 0.05%-0.5% of carbon nano tubes with the tube diameter being 5-20 nm and the length being 1-10 microns are further included, the tensile strength of the carbon nano tubes is not lower than 600 MPa, the specific strength of the carbon nano tubes is not lower than 200 MPa.cm / g, the rare earth elements refine grains and the like, the carbon nano tubes and the ceramic particles synergistically enhance the performance, and the ceramic particles are evenly dispersed and strongly combined with a matrix. The ceramic aluminum alloy is high in tensile strength and excellent in specific strength, rare earth elements refine grains to improve toughness, ceramic particles and carbon nanotubes are synergistically strengthened, the conductivity is further improved, the preparation process can overcome traditional problems, industrial production is achieved, the application prospects in the fields of aerospace, automobiles, electronics and the like are wide, and industry progress is promoted.

The application provides a variable-price rare earth element doped black titanium dioxide catalyst and a preparation method and application thereof, and belongs to the technical field of environmental functional materials and water pollution treatment. The catalyst is prepared by a sol-gel method combined with calcination in a hydrogen-argon mixed atmosphere, with tetrabutyl titanate as a titanium source and lanthanum nitrate and cerium nitrate as rare earth doping sources. Lanthanum / cerium doping can effectively inhibit the generation of rutile phase in the black titanium dioxide, increase the specific surface area, narrow the band gap and construct oxygen vacancy defects, and significantly improve the photocatalytic activity. The preparation process is simple, the cost is controllable, the catalyst has a remarkable selective degradation effect on specific dyes, and an efficient solution is provided for dye wastewater treatment.

The invention relates to a microbial growth activation accelerant based on rare earth elements as well as a preparation method and application thereof, and belongs to the field of resources and environments. The microbial growth activation accelerant based on the rare earth elements is prepared from the following components: 1 to 150g of a rare earth compound, 0.2 to 2g of pantothenic acid, 0.2 to 2g of nicotinic acid, 0.02 to 0.1 g of nicotinamide and 1000g of deionized water, the rare earth compound is one or combination of more of chlorides of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium and yttrium, nitric acid compounds and sulfuric acid compounds. A large number of cheap light rare earth elements are used as raw materials of the microbial accelerator, a new utilization approach is provided for the light rare earth elements, the light rare earth elements are converted into high-added-value products, pollution of the light rare earth elements to the environment is reduced, and meanwhile new elements are introduced into the field of microbial accelerators. More importantly, the preparation method of the microbial growth activation accelerant based on the rare earth elements provided by the invention is simple in production process and convenient for large-scale production.

The present application relates to the technical field of metallurgical chemical industry, in particular to a silicon-manganese alloy smelting method, comprising the following steps: raw material pretreatment, gradient reduction smelting, tapping and refining, and flue gas slag cooperative treatment.In the silicon-manganese alloy smelting, lanthanum cerium oxides in the rare earth composite material react with impurities such as sulfur, phosphorus and oxygen in the melt at high temperature, forming high-melting-point compounds and separating with the molten slag, effectively reducing the impurity content, at the same time, the rare earth elements segregate at the grain boundaries, inhibiting atomic diffusion and migration, significantly refining the alloy grain size, and the rare earth composite material is optimized through the dual action of chemical purification and physical modification, solving the problems of impurity segregation and insufficient toughness in the traditional silicon-manganese alloy smelting process, and significantly improving the mechanical properties of the silicon-manganese alloy.

The present invention belongs to the technical field of permanent magnetic materials, and relates to a heavy rare earth-free high-performance lanthanum-cerium rare earth permanent magnet and a manufacturing method thereof. The chemical composition of the lanthanum-cerium rare earth permanent magnet is expressed as: [(R1) 1‑x (R2) x ] a M1 b M2 c M3 d B e Fe 1‑a‑b‑c‑d‑e , wherein: 10%≤x≤25%, 29.5%≤a≤32.5%, 1%≤b≤2%, 0.5%≤c≤1%, 0%<d<2.5%, 0.85%≤e≤0.95%, wherein R1 is one or both of Pr and Nd, R2 is one or both of La and Ce, M1 is Cu and Ga, M2 is Nb and Zr, and M3 is one or more of Al, Co, and Mn. The present invention reasonably controls the composition of the permanent magnet to obtain a high-performance lanthanum-cerium magnet without adding heavy rare earth elements, effectively reduces the production cost of the magnet, and broadens the application of the lanthanum-cerium magnet in the market.

The application relates to the alloy technical field and discloses a high-strength silver-copper alloy and a preparation method. Acidified carbon nanotubes are functionally modified, -NCO groups are introduced by reacting toluene-2,4-diisocyanate with surface active groups, and a plurality of carboxyl groups are grafted on the surface of the carbon nanotubes by reacting the -NCO groups with the hydroxyl groups of 4-hydroxyphthalic acid. The carboxyl groups can firmly adsorb lanthanum nitrate through coordination, avoid the separation of rare earth elements in the ball milling process with raw materials, ensure the uniform distribution, reduce the carbon nanotube agglomeration tendency, and improve the dispersity of the carbon nanotubes in the silver-copper alloy. The carbon nanotubes have extremely high axial strength and excellent conductivity, the load transmission and the conductive network effect can enhance the mechanical and electrical properties of the alloy material, the rare earth lanthanum is segregated at the grain boundary to form a pinning effect to refine the grains, the alloy strength is further improved, and the strength and the conductivity of the silver-copper alloy are synergistically improved.

The invention discloses lanthanum-doped aluminum oxide composite grinding powder and a preparation method thereof, and relates to the technical field of aluminum oxide grinding powder, the aluminum oxide grinding powder has high grinding efficiency, is suitable for grinding and polishing materials such as metal, glass and ceramic, and has wide applicability; lanthanum serving as a rare earth element is doped into the aluminum oxide grinding powder, so that growth of aluminum oxide grains can be better inhibited, and the high temperature resistance of the grinding powder is improved; the lanthanum-doped aluminum oxide grinding powder has higher wear resistance, the oxygen vacancy concentration on the surface of aluminum oxide can be adjusted by doping lanthanum, and the polishing performance of the grinding powder is optimized.

The present invention relates to a method for preparing a catalyst composition for preparing a catalyst composition having improved catalyst activity by pre-treating a hydrogen-bonded lanthanide rare earth element compound and / or an oligomer type of a lanthanide rare earth element compound , which induce the deterioration of the catalyst activity, and a method for preparing a conjugated diene-based polymer using the catalyst composition prepared thereby.

The present invention provides defect-controlled fluoride crystals, a method for producing the same, and the use thereof. These fluoride crystals contain at least a rare earth element RE (RE is at least one element selected from the group consisting of cerium (Ce), praseodymium (Pr), lanthanum (La), and neodymium (Nd)), fluorine (F), and hydrogen (H), and have the same crystal structure as crystals represented by CeF3. A method for producing fluoride crystals according to the present invention comprises growing crystals from a raw material containing a rare earth element RE and a raw material containing fluorine (F) by a solvothermal method in the presence of at least one mineralizer selected from the group consisting of mineralizers containing an alkali metal element and / or an alkaline earth metal element, acid mineralizers, and mineralizers containing a normal salt.