141results about How to "Reduce density difference" patented technology

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 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.

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.

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 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 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.

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.

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.

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.

An inkjet image forming apparatus includes ink heads, a drive voltage controller that adjusts density by controlling each drive voltage of the ink heads, a halftone processing controller that adjusts density by changing the number of ink droplets ejected from each nozzle of the ink heads, and a density adjustment controller that prints and scans a density adjustment pattern to calculate an adjustment value of each density level. The density adjustment controller adjusts density of a lowest density level so that the drive voltage controller controls each drive voltage based on the adjustment value of the lowest density level, and adjusts density of each density level other than the lowest density level so that the halftone processing controller changes the number of ink droplets based on the adjustment value of each density level other than the lowest density level and the adjustment result by the drive voltage controller.