159 results about "Particle size ratio" patented technology

Disclosed is multilayer ceramic capacitor. The multilayer ceramic capacitor includes a capacitive part including dielectric layers and first and second internal electrodes alternately laminated therein, wherein the dielectric layers include first ceramic particles having an average particle size of 0.1 μm to 0.3 μm, and one set of ends of the first internal electrodes and one set of ends of the second internal electrodes are exposed in a lamination direction of the dielectric layers, a protective layer formed on at least one of top and bottom surfaces of the capacitive part, including second ceramic particles and having a porosity of 2% to 4%, wherein an average particle size ratio of the second ceramic particles to the first ceramic particles ranges from 1.1 to 1.3; and first and second external electrodes electrically connected to the first and second internal electrodes exposed in the lamination direction of the dielectric layers.

A green article comprising an A-B powder mixture and methods of manufacturing such green articles and corresponding sintered articles are disclosed. The A-B powder mixture consists of a minor volume fraction of a relatively fine powder A and a complementary major volume fraction of a relatively coarse prealloyed powder B wherein the A-B powder mean particle size ratio is at least about 1:5. Metal powder A consists of one or more elemental metals or alloys which has a melting or solidus temperature above the highest sintering temperature at which the A-B powder mixture may be sintered without slumping. Prealloyed metal powder B consists of one or more alloys which are amenable to supersolidus liquid phase sintering. Green articles made from the A-B powder have a wider sintering temperature window than do articles made from prealloyed metal powder B alone.

An electroconductive bonding material contains a thermosetting resin, a low-melting-point metal powder which is melted at a temperature equal to or lower than the thermosetting temperature of the thermosetting resin, a high-melting-point metal powder which is not melted at a temperature equal to or lower than the thermosetting temperature of the thermosetting resin and which reacts with the low-melting-point metal powder to form a reaction product having a high melting point of 300° C. or higher during heat-hardening of the thermosetting resin, and a reducing substance which removes an oxide formed on the surface of the high-melting-point metal powder. The total content of the low-melting-point metal powder and the high-melting-point metal powder is 75% to 88% by weight, and the particle size ratio D1/D2 of the average particle size D1 of the low-melting-point metal powder to the average particle size D2 of the high-melting-point metal powder is 0.5 to 6.0. Thereby, an electroconductive bonding material is provided which has good conduction properties and high connection strength even when reflow heat treatment is repeatedly carried out or thermal shock accompanied with a rapid temperature change is applied to the electroconductive bonding material, and an electronic apparatus using such an electroconductive bonding material.

The invention belongs to the technical field of preparation of magnetic materials and discloses a preparation method of a low-loss high permeability Fe-Si-Al magnetic powder core. The method comprises the following steps: (1), adopting a medium-frequency induction furnace, and smelting Fe-Si-Al alloy ingot casting by using casting powder; (2), mechanically crushing the Fe-Si-Al alloy ingot casting into power, performing annealing treatment, screening, and making into Fe-Si-Al alloy powder according to different particle size ratio; (3), performing insulating treatment on the Fe-Si-Al alloy powder, adding an internal lubricant, a releasing agent and then compression moulding forming, preparing into a compression molding product with the density being 6.0-6.2 g/cm<3>; (4), performing heat treatment on the compression molding product, and carrying out surface insulation coating to obtain the Fe-Si-Al magnetic powder core. The preparation method of low-loss high permeability Fe-Si-Al magnetic powder core is low in cost, convenient to operate, high in performance, high in magnetic conductivity and low in high-frequency loss.

The present invention provides a positive electrode active material for lithium ion battery having good rate characteristics. The positive electrode active material for lithium ion battery has a layer structure expressed by a composition formula: Li_x(Ni_yMi_1-y)O_z, wherein M represents Mn and Co, x represents 0.9 to 1.2, y represents 0.6 to 0.9, and z represents 1.8 to 2.4. The positive electrode active material has a particle size ratio D50P/D50 of 0.60 or more, wherein D50 is the average secondary particle size of the positive electrode active material powder, and D50P is the average secondary particle size of the positive electrode active material powder after pressing at 100 MPa. The positive electrode active material contains 3% or less particles having a particle size of 0.4 μm or less in terms of the volume ratio after pressing at 100 MPa.

The silica sol of the invention contains silica particles having a mean primary particle size of 20 to 100 nm and which has a silica particle size/mean primary particle size ratio, determined through dynamic light scattering, of 3.0 or less, wherein the silica particles are surface-treated with an organic silane compound and have an α-ray emission rate of 0.005 counts/cm²·hr or less and a moisture absorption coefficient, determined after allowing the silica particles to stand for 48 hours at 23° C. and a relative humidity of 50 RH %, of 0.5 mass % or lower.

The invention relates to a high-oxygen index thermoplastic low-smoke halogen-free polyolefin cable material and a preparation method thereof. The material is prepared from the following components: 40-60 parts of ethylene-vinyl acetate copolymer (EVA), 10-35 parts of linear low-density polyethylene (LLDPE), 2-25 parts of ethylene-octylene copolymer (POE), 10-30 parts of an interfacial compatibilizer (grafting material and silicone master batches), 100-180 parts of aluminum hydroxide (the aluminum hydroxide of which the particle sizes are smaller than 1 micron accounts for about 0-50% and the aluminum hydroxide of which the particles sizes are 1-10 microns accounts for 50-100%), 0-50 parts of other fire retardants, 0-4 parts of an antioxidant and 1-10 parts of other mill base and the like. Compared with the prior art, the high-oxygen index thermoplastic low-smoke halogen-free polyolefin cable material has the advantages that the aluminum hydroxide materials with different particle size ratios are selected, so that a product has the characteristics of a high oxygen index, high mechanical strength, good processability and the like. The product can be applied to sheaths or insulating materials of a power cable, a control cable, an optical cable, a local cable, a signal cable and various transmission cables, plays a structural flame retardant role and is used for improving the flame resistance of the cable.

The invention discloses a displacement experiment artificial core analysis preparing method based on experimental and mathematical algorithms, and the method combines qualitation with quantitation. The method comprises the steps that physical parameters of an artificial core are used as target parameters for preparation of the artificial core; influencing factors of the physical parameters of theartificial core are determined; multiple sets of combined experiment schemes are made, and the artificial core is prepared according to all the combined experiment schemes, and the physical parametersof the artificial core are measured after preparation is completed; preparation condition parameters of all the combined experiment schemes are used as basis, and based on a gray correlation analysismethod, relevancy degrees of all the influencing factors and all the target parameters are determined; according to the relevancy degree rank of all the influencing factors and the target parameters,larger influencing factors and smaller influencing factors are determined; based on a statistic analysis result of the gray correlation analysis method and a BP neural network theory, a particle sizeratio prediction mathematical model is built; a matching prediction result is calculated through the particle size ratio prediction mathematical model and serves as a reference which provides data support for artificial core manufacturing.

The invention relates to a sintered mixture preparation method, a sintered mixture distribution apparatus and a sintered mixture distribution method, wherein the raw materials of the sintered mixturecomprise iron ore powder, coke powder, return ore, quicklime and limestone. The sintered mixture preparation method comprises: placing iron ore powder, quicklime, return ore with a particle size of less than 3 mm after wetting, coke powder with a particle size of less than 3 mm, limestone and water to a primary mixer, and uniformly mixing to obtain a primary mixture; and placing the primary mixture, return ore with a particle size of 3-5 mm after wetting, coke powder with a particle size of more than 3 mm, limestone with a particle size of greater than 3 mm and water to a secondary intensive mixer, and uniformly mixing to prepare the sintered mixture. The sintered mixture distribution method comprises: distributing the sintered mixture onto a sintering machine in layers through the sintered mixture distribution apparatus comprising three sets of multi-roller material distributors, wherein the particle sizes of the layers are sequentially reduced from bottom to top, the particle size ofthe first layer is more than 8 mm, the particle size of the second layer is 5-8 mm, the particle size of the third layer is 3-5 mm, and the particle size of the uppermost layer is less than 3 mm. According to the present invention, the particle size ratio of the sintered mixture is improved, the precise segregation multi-layer material distribution is achieved, and the gas permeability and the sintering utilization coefficient of the sintered mixture are improved.

The invention relates to a preparation method for non-close-packed SiO2 photonic crystals. The preparation method comprises the following steps: taking tetraethoxysilane as a raw material, thereby preparing SiO2 nanometer and submicron sphere grains; ultrasonically and automatically assembling two SiO2 sphere grains at a certain particle size ratio, thereby obtaining a double-size photonic crystal structure; and roasting, etching and cleaning the double-size photonic crystal structure, thereby obtaining the non-close-packed SiO2 photonic crystals. The preparation method provided by the invention is short in preparation period and simple in processing equipment.

A rechargeable lithium battery that includes: a negative electrode including a negative active material, and a positive electrode including a positive active material and activated carbon. When the positive active material includes a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium titanium-based oxide, a lithium nickel manganese-based oxide, a lithium nickel cobalt manganese-based oxide, a lithium nickel cobalt aluminum-based oxide, or a combination thereof, the average particle diameter of the activated carbon is greater than about 100% and less than about 1000% of the average particle diameter of the positive active material. When the positive active material includes a lithium iron phosphate-based compound, the average particle diameter of the activated carbon is greater than or equal to about 1000% and less than or equal to about 3000% of the average particle diameter of the positive active material.

The invention belongs to the technical field of photocatalysis, in particular to an in-phase junction photocatalyst, a preparation method and an application thereof. The in-phase junction photocatalyst comprises in-phase semiconductor materials with different particle diameters, wherein the small particle diameter semiconductor material is loaded on the surface of the large particle diameter semiconductor material; and the particle size ratio of the large particle size semiconductor material to the small particle size semiconductor material is (40-100): 1. The same crystal phase semiconductormaterials with different particle sizes are utilized to form junctions, so that the efficiency of separating photogenerated electrons and holes can be effectively promoted, and the photocatalytic performance of the materials is obviously improved. The embodiment results show that when the in-phase junction photocatalyst is used for photocatalytic decomposition of water, the hydrogen generation amount can reach 150 umol/h/g.

A phosphorescent transfer sheet includes a support, and a transfer layer detachable from the support, wherein the transfer layer includes hot melt adhesive particles and phosphorescent pigments. The average particle diameter of the hot melt adhesive particles may be about 30 to 150 μm, and the average particle diameter of the phosphorescent pigment may be about 5 to 40 μm. The average particle size ratio of the hot melt adhesive particles to the phosphorescent pigment is about 1/1 to 10/1. Phosphorescent pigments include strontium-containing phosphorescent pigments. In the transfer layer, a protective layer detachable from the support may be interposed between the support and the transfer layer. Phosphorescent transfer sheets ensure clear glossy or glossy images even in dark places after transfer.

The invention discloses a preparation method of a double-shell soft magnetic composite material. A nitride/oxide double-shell structure is prepared on the surface of high-purity iron powder by a chemical heat treatment process, wherein nitride on the inner layer is used as a transitional layer, and is matched with matrix lattices; and by oxide on the outer layer, the resistivity of an iron power core is further increased on the basis of nitriding, and loss of the iron powder core is reduced favorably. Meanwhile, double shells of nitriding and oxidizing have ferromagnetism, a magnetic dilutioneffect is greatly reduced, and the saturation flux density of the composite material is improved. The preparation method comprises the following key steps: (1) reducing iron powder with a certain particle size ratio in high-purity hydrogen to remove surface oxide; (2) feeding mixed gas of ammonia gas and hydrogen to carry out surface nitriding so as to obtain a Fe4N thin layer on the surface of the iron powder; (3) feeding an oxygen-containing atmosphere to carry out surface oxidizing so as to obtain a double-shell core-shell structure of which the inner shell is Fe4n and the outer shell is Fe3O4; and (4) adding a binder and a lubricating agent in the prepared iron powder, pressing to obtain a soft magnetic composite material and then carrying out vacuum heat treatment.

The invention discloses special zirconium-aluminium composite ground micro-powder for the optoelectronic industry and a production method for the same. The special zirconium-aluminium composite ground micro-powder for optoelectronic industry is produced from two main raw materials, namely, fused alumina and zirconium silicate, via ball-milling, water-washing, grading, compounding, surface coating, filtering, spray-drying and sieving, wherein the compounding ratios of the contents of the raw materials are as follows: the content of alumina particles is 30-50%, and the content of zirconium silicate particles is 70-50%. The product disclosed by the invention is reasonable in particle shape collocation, wide in particle size distribution, stable in median diameter, high in basic particle size ratio, without large particles and ultrafine particles, excellent in interparticle lubrication property, and especially suitable for grinding and polishing high-tech products in the optoelectronic industry.

The invention discloses preparation and application of a nano mesoporous Fe3O4-chitosan core-shell cross-linked microsphere material, and belongs to the field of preparation and water treatment research and application of nano mesoporous Fe3O4-chitosan core-shell cross-linked microspheres. Based on controllable synthesis of mesoporous Fe3O4 microspheres, chitosan is used as a synthesis process regulating agent and a stable matrix for the first time, chloroethanol is used as a cross-linking agent, ferric trichloride, ethylene glycol and sodium acetate are used as reaction raw materials and auxiliary materials, through regulation and control of the growth and cross-linking of nanoparticles, the improvement of the porosity of the nanoparticles, the increase of the specific surface area and the effective crosslinking of the particles are realized. The particle size of the obtained cross-linked microsphere is 200-450 nm, the specific surface area is 6.2 m<2>/g, the pore size is about 7 nm,the particle size distribution is narrow, the cross-linked microsphere has high magnetism (40-85 emu/g), cross-linked chitosan provides a strong matrix, and the physical stability of the cross-linkedmicrosphere is enhanced.