143results about How to "Reduce density difference" patented technology

The invention discloses a preparation method of a high-thermal conductivity graphene-Sn-Ag composite brazing filler metal, ad relates to a preparation method of a high-thermal conductivity composite brazing filler metal. The preparation method has the following purposes: the problem of graphene floating and agglomeration in the preparation and application process of the composite brazing filler metal is solved by reducing a greater density difference between graphene and an Sn-Ag brazing filler metal matrix through plating a metal on the graphene; meanwhile, the graphene is dispersed more uniformly in the brazing filler metal matrix; and the reliability of sealing and brazing is improved by improving the heat conductivity of the composite brazing filler metal through adding the graphene. The method comprises the following steps: (1) the metal is plated on the graphene; and (2) the ball milling, the mixing and the medium-temperature smelting are performed for the metal-plated graphene and the Sn-Ag brazing filler metal to obtain the high-thermal conductivity composite brazing filler metal. The prepared composite brazing filler metal is high in thermal conductivity, has a higher wettability compared with a traditional Sn-Ag brazing filler metal, and is a composite brazing filler metal accordant with the present development tendency of an electronic industry as a connecting material of traditional large-scale integrated circuits.

A lead-free solder characterized as comprising 0.1 to 2 wt % of Cu, 0.002 to 1 wt % of Ni with the residue being Sn. The solder preferably contains Cu in an amount of 0.3 to 0.7 wt %, and more preferably it contains Cu in an amount of 0.3 to 0.7 wt % and Ni in an amount of 0.04 to 0.1 wt %. The solder can be prepared by adding Ni to a molten mother alloy of Sn--Cu, or by adding Cu to a molten mother alloy of Sn--Ni. A lead-free solder which further comprises 0.001 to 1 wt % of Ga is also disclosed. The lead-free solder can form a solder joint having a high strength and stability comparable to those of a conventional Sn--Pb eutectic solder.

The invention relates to lightweight aggregate concrete for heat preservation of structures, and belongs to the technical field of building materials for civilian use. The lightweight aggregate concrete for heat preservation of structures comprises the following raw materials in parts by mass: 360-460 parts of cement-based cementing material, 410-460 parts of ceramsite, 110-120 parts of modified vitrified micro balls, 15-20 parts of concrete modifier, 260-290 parts of water and 3.6-4.6 parts of water reducing agent. The lightweight aggregate concrete for heat preservation of structures with the heat conductivity coefficient of 0.25-0.4W / (m.K) and the dry apparent density of 900-1200kg / m<3> is obtained by using the modified vitrified micro balls and the ceramsite as aggregates under the synergistic effect of the components according to a reasonable component proportion, and after the lightweight aggregate concrete is cured for 28 days, the compressive strength of the lightweight aggregate concrete is 8-15MPa. The lightweight aggregate concrete for heat preservation of structures has good heat preservation performance and relatively high strength. Compared with the strength of a full lightweight concrete material prepared from ceramsite perlite, the strength of the lightweight aggregate concrete is obviously improved; compared with the heat conductivity coefficient of a full lightweight concrete material prepared from ceramsite pottery sand, the heat conductivity coefficient of the lightweight aggregate concrete is obviously reduced; and the lightweight aggregate concrete can be used as a lightweight aggregate concrete material for heat preservation of structures.

The invention relates to a high polymer chemically-modified asphalt composition and a preparation method thereof. The preparation method comprises the following steps: chemically modifying rubber, elastomer and base asphalt, and additionally matching stuffing and processing aids; premixing the materials by high polymer processing equipment to prepare the master batch of the modified asphalt; and fully dispersing the master batch into the asphalt by a high-speed shear mixer or by mechanical stirring. Or the modified asphalt material can be prepared by firstly pre-preparing a viscous liquid mixture of modified asphalt and then stirring and mixing the viscous liquid mixture of modified asphalt with the base asphalt. The modified asphalt material prepared by the invention has stable storage performance at high temperature, good performance at high temperature and low temperature, stable processing and preparation and simple and convenient method, and not only can be directly used in factory production but also can be used for road laying sites and in the construction of waterproofing materials.

A radar position selection method based on a three dimensional laser scanner and a GIS (Geographic Information System) is characterized in that the three dimensional laser scanner and a portable lifting platform are adopted, auxiliary devices such as an RTK and a target are matched for use, position three dimensional point cloud data can be quickly and accurately got, and high-precision DEM data are generated after data processing; on this basis, a skyline tool with a three dimensional space analysis function of the GIS is used to generate a skyline, then heights of various points of the skyline are extracted according to the skyline and imported topographic data, shielding angle data are generated, and a radar shielding angle figure and a radar plane detection range figure are generated according to the shielding angle data and radar parameters; a sight line analysis tool of the GIS is used to generate a visible line in a certain direction at an observation point, heights of various points of the visible line are extracted according to the visible line and the imported topographic data, so as to generate a cross-section diagram, undulation of a radar reflection area is analyzed, quantified undulation data are obtained, and a proper radar position erection location is favorably selected on this basis.

The invention relates to a lightweight aggregate concrete suitable for high remote pumping. The lightweight aggregate concrete is characterized by comprising the following components in percentage by weight: 30%-40% of cement paste, 25%-35% of light crude aggregate materials and 30%-40% of refined aggregate materials, wherein the density of the cement paste is not larger than 2000kg / m<3>, the apparent density of the light crude aggregate materials is not smaller than 1000kg / m<3> and the difference between the density of the cement paste and the apparent density of the light crude aggregate materials is smaller than 600kg / m<3>. According to the invention, the cement paste has a viscosity of not smaller than 10mPa.S and is obtained by uniformly mixing the following materials in percentage by weight: 40%-60% of cement, 10%-20% of fly ash, 0%-20% of lightweight powder, 3%-5% of wollastonite, 20%-32% of water, 1%-4% of an inorganic viscosity modifier, 0%-0.2% of cellulose ether and 0.5%-1.4% of a polycarboxylic acid high-performance water reducer. The lightweight aggregate concrete has good workability, uniformity and pumpability, and can be used for high remote pumping.

A combined circulating fluidized-bed boiler is composed of combustion chamber, cyclone separator, throat, material return valve and air distributing plate, and features that said throat can divide the combustion chamber into several combustion chambers for intensifying the combustion of particles in combustion chamber.

The invention provides magnetorheological fluid comprising macromolecular composite magnetic powder and a preparation method thereof, and belongs to the technical field of magnetic materials and functional materials. The magnetorheological fluid comprises the composite magnetic powder, carrier liquid and a thixotropic agent, wherein the composite magnetic powder is the magnetic powder coated with polyether sulphone macromolecules. The preparation method of the magnetorheological fluid comprises the following preparation steps: firstly preparing the composite magnetic powder by using a solvent evaporation drying method, then mixing the carrier liquid and the thixotropic agent by stirring, adding the composite magnetic powder, and preparing the uniformly dispersed magnetorheological fluid comprising the special engineering macromolecular composite magnetic powder by ultrasound and stirring. The preparation method of the magnetorheological fluid system is simple and convenient for large-scale production; and the special engineering macromolecules are used as coating materials of the ferromagnetic powder; the problems of sedimentation and oil resistance are solved; and the magnetorheological effect of the system is maintained at a very high level.

The invention relates to full-lightweight ceramsite concrete and a preparation method thereof. The full-lightweight ceramsite concrete is prepared from, by weight, 278-339 parts of cement, 318-344 parts of ceramsite, 334-382 parts of pottery sand, 50-55 parts of coal ash, 35-42 parts of silica fume, 0.001-3 parts of triisopropanolamine, 0.5-3 parts of a water reducing agent and 0.001-3 parts of athickening agent. The method includes steps: subjecting ceramsite and pottery sand to surface pretreatment through alkyl alkoxy silane, prewetting ceramsite and pottery sand to achieve a saturated surface dry state, then sequentially feeding lightweight aggregates, cement, silica fume and coal ash into a forced mixer, and well mixing to obtain the full-lightweight ceramsite concrete. The full-lightweight ceramsite concrete prepared according to the method has advantages of light weight, high peaceability and effectiveness in inhibition of ceramsite floating and has a promising application prospect in the field of energy-saving construction engineering.

A sintered metallic bearing obtained by compacting raw-material powders comprising Cu powders, SUS powders, and pure-Fe powders and thereafter sintering the compact at a given temperature.

The invention relates to Ni / TiO2-based electromagnetic rheological liquid with electromagnetic coupling effect and a preparation method thereof. The dispersed phases of the electromagnetic rheological liquid are composite particles which are respectively in a core-shell structure, wherein nano-metallic conductive particles (Ni) are taken as a core, titanium dioxide (TiO2) is taken as a coating shell, and the composite particles are modified by polar molecules. The preparation method comprises the following steps: preparing nano-nickel particles by using a physical method, wherein the particlediameter is 30-200nm; carrying out hydroxylation treatment on the nano-nickel particles to obtain particles A; coating TiO2 on the particles A to obtain particles B; carrying out heat treatment on the particles B to obtain Ni / TiO2 composite particles or coating urea and SDBS polar molecules at the outer layers of the particles B to obtain particles C; carrying out heat treatment on the particles C to obtain Ni / TiO2 / Urea and Ni / TiO2 / SDBS composite particles; and dispersing the composite particles into the basic liquid to obtain the electromagnetic rheological liquid in which the volume concentration of the composite particles is 10-50%. The preparation method of the invention is simple and can be operated easily; a sol-gel method and a controllable molecule synthesizing technology are adopted; and the prepared electromagnetic rheological liquid not only has the properties of the electro-rheological liquid but also has the properties of the magneto-rheological liquid.

The invention relates to a method for preparing pyruvic oxidase. The method comprises the steps as follows: (1), cultivation of microbial cells containing the pyruvic oxidase, centrifugal collection of bacterial cells, and cell disruption; (2), preparation of a polyethylene glycol / inorganic salt two-aqueous phase extraction system solution; (3), three times of extraction separation by the aid of a two-aqueous phase extraction system, and obtaining of an inorganic salt solution of the pyruvic oxidase; and (4), flirtation and concentration of an ultrafiltration membrane, freezing and drying of a trapped fluid, and preparation of a pyruvate oxidase product. The method can prepare the pyruvic oxidase continuously in a large scale, the preparation technology of the oxidase is simple and convenient, the production period is short, the operation condition is mild, the recovery rate of the oxidase activity is high, and the production cost of the pyruvic oxidase is lower.

The invention relates to lightweight high-strength ceramsite concrete as well as a preparation method and application thereof, and relates to the field of building materials. The ceramsite concrete iscomposed of the following components in parts by weight: 400 to 530 parts of a cementing material, 420 to 460 parts of coarse aggregate, 650 to 850 parts of fine aggregate, 6.8 to 21 parts of admixtures, and 160 to 220 parts of water, wherein the coarse aggregate is fly ash ceramsite, the fine aggregate is composed of furnace slag and sand, and the admixtures include a polycarboxylic acid water reducing agent and an enhancing agent. The method uses ultra-fine modified fly ash, cement and activated silicon micropowder as the cementing material, the furnace slag and the river sand as the fine aggregate, and the fly ash ceramsite as the coarse aggregate to prepare the lightweight high-strength prefabricated component, and effectively solves the problem of ceramsite concrete layering due to asmall ceramsite density, and the prepared ceramsite concrete has high strength, is convenient for actual construction operation, and effectively uses solid waste, thereby facilitating environmental protection.

In a color image processing apparatus, in a compression process section (an image compressing apparatus), when an original document is compressed, the edges of black texts and / or line drawings in the original document is detected, then a foreground layer (a first image) is generated in which the detected edges are expressed in the form of a binary image, and then lossless compression is performed on the foreground layer. Further, a background layer (a second image) is generated in which a density difference of the edges from the other parts in the original document is reduced, and then lossy compression is performed on the background layer. Then, these layers are combined into a compressed file.

The invention relates to aggregate floating prevention lightweight ceramsite concrete. The aggregate floating prevention lightweight ceramsite concrete is prepared from the following components: coalash, lightweight ceramsite, ceramsite sand, fine aggregate, hydrogen peroxide, hydroxypropyl methyl cellulose, welan gum, water and a polycarboxylic admixture according to the mass ratio of (200 to 300):(20 to 40):(20 to 60):(180 to 400):(100 to 160):(180 to 450):(6 to 12):(0.024 to 0.048):(0.048 to 0.192):(125 to 150):(4 to 8). The volume weight of the prepared lightweight ceramsite concrete canbe adjusted in the 800-1500 kg / m<3> interval, the strength interval is 5-30 MPa, and the heat conductivity interval is 0.15-0.25 W / m.K; broken ceramsite slag is adopted as ceramsite sand, the accumulation storage problem of the broken slag as waste is solved, and the aggregate floating prevention lightweight ceramsite concrete has good social and economic benefits.

The invention relates to a preparation method for a composite negative electrode of a lead-carbon battery, and the composite negative electrode and application thereof. The preparation method comprises the following steps: producing lead sulfate in porous carbon in situ so as to improve the bulk density of a carbon material and reduce the density difference between the carbon material and lead powder; and then uniformly mixing modified activated carbon, lead powder and additives by using a shearing process so as to prepare the high-performance composite negative electrode for the lead-carbon battery. The composite negative electrode for the lead-carbon battery prepared by using the method has higher charge-discharge reversibility, longer charge-discharge cycle life and higher charge acceptance than conventional lead-acid batteries, and is easy to realize large-scale production.

The invention discloses a manufacturing method for an oil pump rotor, and belongs to the technical field of oil pump parts. The manufacturing method includes the steps of mixing, blank pressing, pre-combusting, re-pressing, sintering, shaping, tempering, secondary shaping and heat treating, and finally finished products with the final density greater than or equal to 7.2 g / cm<3> and the rigidity greater than or equal to HRC40 can be obtained. According to the manufacturing method, the cycloidal rotor is produced through the powder metallurgy pressing method, mass production can be realized, the production efficiency is high, the product stability is good, and the material utilization rate is high. The density of the produced cycloidal rotor can reach 7.2 g / cm<3> which cannot be realized through common powder metallurgy methods; the product rigidity can reach HRC40 or above after quenching, the abrasion resistance is good, and the service life is greatly prolonged; and the material utilization rate is increased, the machining difficulty is lowered, the production efficiency is improved, and the product stability is improved.

The invention relates to a preform structure of a carbon / carbon composite material thick plate and a thick plate preparation method. The preform structure consists of a core layer and tire net layers.The core layer is a carbon fiber felt with a thickness of 20-40mm. The tire net layers are carbon fiber mesh tires needle punched on both sides of the core layer. The thick plate preparation method includes: placing the preform structure in a chemical vapor carburizing furnace, conducting chemical vapor carburizing densification, and then performing graphitization treatment and machining in order; and repeating the above technological process until the density of the carbon / carbon composite material reaches the design requirement. The preform structure of the carbon / carbon composite materialthick plate utilizes the mesh tire layers as the carbon source gas transmission medium to guide the carbon source gas evenly to the core layer, thus lowering the density difference of the core layer thickness direction, and solving the surface hole sealing problem of the core layer. The prepared the high density carbon / carbon composite material thick plate has a thickness of 20-40mm and a densityof 0.4-0.8g / cm<3>.

A treatment apparatus for evaporated fuel including tank port, a purge port, an atmosphere port, a channel communicating the tank port or the purge port and the atmosphere port, and plural adsorption chambers having adsorbent therein, which adsorbing and desorbing a fuel component of evaporated fuel, wherein the adsorption chamber closest to the atmosphere port has a major diameter portion filled with the adsorbent over all a cross section of the charmed a projecting portion projecting from the major diameter portion toward the atmosphere port and filled with the adsorbent, and a space portion between the projecting portion and an inner wall of the channel and not filled with the adsorbent, and end surfaces of the major diameter portion and the projecting portion on the atmosphere port side are breathable so as to control temperature drop in activated carbon and to thereby enhance bleed emission performance.

The invention discloses a polyol composition composed of a plurality of polyether polyols and a polyol I, wherein the polyol I is prepared through an addition reaction with an olefin oxide by using areaction product, generated through a reaction of cardanol glycidyl ether with a plurality of amines, as an initiator, wherein the typical characteristic viscosity of the polyol I is 1500-3000 mPa*s,and hydroxyl value is 300-450 mg(KOH) / g. The invention also discloses an application of the polyol composition in polyurethane hard foam plastic and a preparation method thereof. In the invention, thepolyol I, prepared with the cardanol derivative being an initiator, has a long alkane structure, so that the polyol I has excellent compatibility with a component in which cyclopentane or a composition serves as a foamer. The polyurethane hard foam prepared from the polyol is reduced in foam density difference, is high in closed-pore ratio, is reduced in comprehensive heat-conductive coefficient,and is improved in compression strength and dimensional stability.

The invention provides a Ta-doped potassium sodium niobate-based piezoelectric ceramic material and a preparation method thereof. The general formula of the piezoelectric ceramic is Na<0.5>K<0.5>Nb<1-y>Ta<y>O<3>, wherein y is greater than or equal to 0.11 and less than or equal to 0.2; the invention discloses a preparation method of the piezoelectric ceramic material. The preparation method comprises the following steps: carrying out microwave hydrothermal synthesis of Na0.5K0.5Nb1-yTayO3 powder; taking a 7mol / L mixed alkali liquor of NaOH and KOH as a solvent, taking Nb2O5 and Ta2O5 as reactants, wherein the ratio of Na+ to K+ is 1: 1 6, the adding total amount of Nb2O5 and Ta2O5 to the mass molar ratio of the solvent is 1: 8-1: 12, the mass molar ratio of Nb2O5 to Ta2O5 is 8: 1-4: 1, theadding amount of a dispersing agent is 1.5 wt%, the microwave reaction temperature is 160-180 DEG C, and the reaction time is 2-4 hours. The invention also discloses a preparation method for preparing piezoelectric ceramic from the powder by spark sintering, annealing treatment is carried out in an oxygen atmosphere, and the obtained piezoelectric ceramic has good electrical properties.

In a reliable semiconductor device and a method of fabricating the semiconductor device, a difference in height between upper surfaces of a cell region and a peripheral region (also referred to as a level difference) is minimized by optimizing dummy gate parts. The semiconductor device includes a semiconductor substrate including a cell region and a peripheral region surrounding the cell region, a plurality of dummy active regions surrounded by a device isolating region and formed apart from each other, and a plurality of dummy gate parts formed on the dummy active regions and on the device isolating regions located between the dummy active regions, wherein each of the dummy gate parts covers two or more of the dummy active regions.

The invention relates to a method for manufacturing a soundboard of a piano. The method comprises the following steps: firstly, dividing boards with different annual ring densities into five classes; secondly, transversely splicing a plurality of boards with the same density into a large board, and arranging the large boards according to the annual ring densities in the same way; and finally, splicing into a whole board, and then cutting into required soundboard shape. According to the method, the boards with different densities are distinguished and are reasonably arranged when being spliced, so that the densities of various parts of the whole soundboard are gradually increased or reduced, the density difference between the adjacent boards is reduced, the destructive effect generated by internal stress of the soundboard due to climatic change is overcome, and the vibration performance of the soundboard is improved, thereby increasing the tone quality of the piano.

A semiconductor device and a method of forming the same, the semiconductor device includes a substrate, a first well and a first dummy cell region. The substrate has a plurality fins disposed therein, and the fins are extended along a first direction. The first well is disposed in the substrate, and a dummy cell region is disposed at a first boundary of the first well. The first dummy cell region includes a first isolation structure and a plurality of first gate structures. The first SDB is disposed in the substrate, along a second direction perpendicular to the first direction to penetrate through one of the fins, and the first gate structures are disposed over the first SDB.

The invention discloses a heat treatment method for high-speed steel for rollers. The chemical composition of the high-speed steel consists of the following components in percentage by weight: C: 3.2 to 3.6; W: 1.2 to 1.6; Mo: 5.0 to 7.0; V: 2.0 to 3.0; Cr: 8.0 to 10.0; Al: 0.1 to 0.4; Ni: 2.2 to 2.6; Co: 6.5 to 7.5; Nb: 0.2 to 0.4; Ti: 0.2 to 0.4; Ce: 0.4 to 0.6; Zr: 0.05 to 0.20; Si: less than 0.8; Mn: less than 1.5; S: less than 0.03; P: less than 0.04; and the balance of Fe. After the high-speed steel is cast to form a billet and the billet is roughly machined, the billet is quenched, the quenching process is carried out when a furnace is heated to 1260 DEG C to 1280 DEG C, the temperature is kept for 3 to 5 hours, the billet is then quenched in oil, and is tempered after being quenched, the tempering process is carried out when the furnace is heated to 620 DEG C to 650 DEG C, the temperature is kept for 5 to 7 hours, the furnace is cooled and then heated to 610 DEG C to 630 DEG C again, the temperature is kept for 5 to 7 hours, and after air cooling and tempering, finish machining is carried out, so that a roller, the dimensional precision and surface roughness of which come up to requirements, is obtained.

The invention relates to a garlic essential oil microcapsule. The garlic essential oil microcapsule comprises the following raw material components in parts by weight: 24-47 parts of whey protein concentrate, 6-24 parts of inulin, 8-15 parts of garlic essential oil, 1.5-9.5 parts of compound vegetable oil and 180-240 parts of water. From principles of relieving poor density of an oil-water systemand reducing Austenitic maturation effect, the emulsibility of the garlic essential oil is strengthened, the stability of the lactescence of the garlic essential oil is enhanced, and therefore, the embedding rate of the garlic essential oil microcapsule prepared by a spray drying technology is increased remarkably; and the whey protein concentrate and the inulin are used as wall materials, the garlic essential oil is embedded by the spray drying technology, the embedding rate of the garlic essential oil is increased remarkably and can reach 74% or above, and the product is easily dissolved inwater, is good in flavor stability and has good slow-release effect.

In order to reduce a density difference that appears when printing whose execution number of scan operations is changed is performed, a CPU acquires a plurality of color conversion LUTs; the CPU performs printing of each of normal portions of color patches using a reference LUT and performs printing of each of hitch portions of the color patches using a corresponding one of mutually different color conversion LUTs; the CPU allows a color patch having a small density difference to be input as a selection result; the CPU identifies a color conversion LUT corresponding to the selection result; and the CPU designates the color conversion LUT corresponding to the selection result as a color conversion LUT for the hitch portion.