66results about How to "Avoid anisotropy" patented technology

The invention discloses an equivalent mismatch model multistage calibration method used for increasing satellite image positioning accuracy. The equivalent mismatch model multistage calibration method comprises following steps: firstly, a space-borne scanning camera imaging positioning model containing equivalent mismatching angles is constructed; in orbit, fixed stars or terrestrial landmarks are observed via controlling camera intervals; equivalent mismatching angle parameter sets of space-borne cameras on star sensor attitude reference caused by thermal deformation on the stars of the same orbit at different times are calculated; mesh generation of the space-borne camera all view based on two-dimensional scanning rotating angles is carried out; in a one orbit cycle, imaging positioning model parameter reconstitution and high accuracy pointing error multi-stage fitting calibration are carried out so as to obtain stable thermal deformation change rule parameter sets used for high accuracy imaging positioning of a next orbit, and avoid imaging positioning problems of singular equivalent mismatching angle calculating caused by few and scattered, or concentrated camera in-orbit sparse or concentrated control points for observing fixed star or landmarks. The equivalent mismatch model multistage calibration method is capable of solving a technical problem, and realizing high accuracy positioning of triaxial stable scanning optical remote sensing satellite when the control points are few and scattered.

The invention relates to a two-dimensional thermal invisible cloak design method with internal heat sources in a hidden region. The method comprises the steps of establishing a two-dimensional coordinate system x-y and determining the region encircled by the coordinate system as a design region; setting boundary conditions, and respectively solving a background temperature field of the design region when no internal heat source is in a region Z1 and a temperature distribution when the internal heat source is in the region Z1 according to the boundary conditions; respectively solving a direct problem, an adjoint problem of the heat sources in regions Z2 and Z3, a derivative of an objective function, a conjugated coefficient, an iterative direction coefficient, a sensitivity problem, an iterative step length and the objective function, and updating the distribution of the heat sources in the regions Z2 and Z3; and calculating a composite objective function of the regions Z2 and Z3. In the two-dimensional thermal invisible cloak design method with the internal heat sources in the hidden region, the heat sources are applied to the design region according to the internal heat sources and the background temperature field in the hidden region to establish an invisible cloak so as to implement an invisible function.

The invention provides a functional film prepared from functionalized organic powder, a low-temperature damage-free manufacturing method and application. The organic powder film material is composed of the functionalized organic powder and polytetrafluoroethylene (PTFE), polytetrafluoroethylene molecular chains are opened through preheated supersonic airflow, the functionalized organic powder is bonded, air in the powder is extruded to form a continuous cake shape, the powder forms a film through a low-temperature hot-pressing process, and then the film material with low porosity and uniform thickness is formed through a multi-layer film hot-pressing compounding process. According to the method, micron-sized organic films can be continuously prepared in a roll-to-roll mode, the physical and chemical properties of the organic powder can be brought into play to the maximum extent, and performance damage caused by high temperature or introduction of a solvent for film formation or anisotropy caused by recrystallization is prevented. No solvent is introduced in the manufacturing process, and the problems of environmental pollution, high energy consumption, uneven film material densityand the like caused in the solvent drying process are avoided.

The invention relates to a method for preparing graphene oxide wrapped silicon nitride composite powder. The method comprises the following steps: performing high-temperature surface oxidation on Si3N4 powder in hydrogen peroxide, putting a coupling agent hydrolysis solution into a surface oxidized Si3N4 suspension, and performing grafting modification treatment on the surface of Si3N4; and preparing a graphene oxide water dispersion, putting the Si3N4 suspension into the graphene oxide water dispersion, performing ultrasonic treatment, leaving to stand till wrapped particles completely settledown, removing supernate, and drying, thereby obtaining the graphene oxide wrapped silicon nitride composite powder. The graphene oxide wrapped silicon nitride composite powder prepared by using themethod is good in wrapping completeness, simple and convenient in process and high in efficiency. Application spaces of silicon nitride and graphene oxide are expanded, and after the graphene oxide wrapped silicon nitride composite powder is applied to a ceramic material, the mechanical properties of the ceramic material can be remarkably improved.

The invention relates to a hard carbon-like graphite cathode material for a high-rate lithium ion battery and a preparation method thereof. The preparation method comprises the following steps of S1,crushing a thermoplastic polymer to obtain polymer powders; S2, dispersing polymer powders in an aqueous solution containing an oxidizing agent and a surfactant for liquid-phase low-temperature oxidation reaction crosslinking, and then pyrolyzing to obtain an oxygen-rich carbon precursor; S3, crushing and graphitizing the oxygen-rich carbon precursor to obtain hard carbon-like graphitized carbon powders; S4, depolymerizing and screening the hard carbon-like graphitized carbon powders to obtain the hard carbon-like graphite cathode material. According to the preparation method, the thermoplastic polymer is used as a raw material, the isotropic oxygen-rich carbon precursor is obtained through liquid-phase low-temperature oxidation crosslinking and pyrolysis treatment, and then the hard carbon-like graphite negative electrode material with low orientation degree and large interlayer spacing is obtained through graphitization treatment, so that the charge-discharge rate performance of thematerial is improved; and when the material is used in the lithium ion battery, the charge-discharge rate can reach more than 15C.

The invention discloses a calcium phosphate-collagen nanometer fiber compound nanometer artificial bone and a preparation method thereof. A calcium phosphate nanometer fiber film serves as a nanometer structural unit and combines with collagen to form the compound nanometer artificial bone; or a collagen nanometer fiber film serves the nanometer structural unit and combines with the calcium phosphate to form the compound nanometer artificial bone. The preparation method comprises the steps of preparing the calcium phosphate nanometer fiber film and collagen nanometer fiber film by using a static spinning device; and alternatively combining with collagen or calcium phosphate after taking the calcium phosphate nanometer fiber film or collagen nanometer fiber film as the nanometer structural unit to form the calcium phosphate-collagen nanometer fiber compound nanometer artificial bone. The compound nanometer artificial bone disclosed by the invention at least comprises one nanometer fiber in calcium phosphate or collagen, has biologic activity, biological compatibility and biomechanic intensity and can be used for repairing defects parts of weight bearing bones, including skulls, limb-stem bones, orofacial bones, vertebral columns and the like and serving as gradient materials to repair the connection parts of cartilages and bones.

The invention relates to a cogging and forging method of a 2507 super duplex stainless steel casting billet, belongs to the technical field of hot processing of duplex stainless steel, and solves theproblem that a small steel ingot cracks during the cogging process. The cogging and forging method comprises the following steps: step 1, loading a furnace with 100 kg to 300 kg of the to-be-cast 2507super duplex stainless steel casting billet; step 2, heating the 2507 super duplex stainless steel casting billet by adopting a stepwise heating method; and step 3, carrying out cogging on the heated2507 super duplex stainless steel casting billet by adopting a two-heating-number forging method, wherein the two-heating-number forging method comprises the procedures of first-heating-number forging, in-furnace remelting for temperature equalization as well as second-heating-number forging, and both the finish forging temperature of the first-heating-number forging procedure and the finish forging temperature of the second-heating-number forging procedure are higher than or equal to 1050 DEG C. By adoption of the cogging and forging method provided by the invention, the 2507 super duplex stainless steel casting billet of which the billet surface quality is good can be obtained.

The invention provides a low-cost and high-performance titanium alloy short process forging process. The process includes the following steps that first, ingot casting is heated to be 1150 DEG C to 1200 DEG C, one heating number forging is conducted, and a forging stock is obtained after cogging; second, the blank obtained in the first step is heated to be 1000 DEG C to 1050 DEG C, and one heatingnumber reversing forging is conducted to obtain a forging stock; third, the blank obtained in the second step is heated to be 1000 DEG C to 1050 DEG C, and one heating number reversing forging is conducted to obtain a forging stock; and fourth, the forging stock in the third step is heated to be 30 DEG C to 50 DEG C below the beta phase transformation point temperature, and 1-3 heating number forging is conducted to obtain a forging stock with uniform structure properties. According to the low-cost and high-performance titanium alloy short process forging process, the technical problems of titanium alloy structure homogenization and fine crystallization through less forging heating numbers are successfully solved, the cost is lowered, and at the same time, the performance index of a titanium alloy is ensured.

The invention relates to the technical field of aluminum alloy and discloses an aluminum alloy composite plate. The aluminum alloy composite plate comprises a first aluminum alloy layer, an aluminum core layer and a second aluminum layer in sequential lamination, wherein the aluminum core layer is an aluminum/aluminum alloy plate with a plurality of grooves. The joint of a core material in a groove structure and a surface material is a plane, and the combination area is larger than that of point-line combination, high combination force and less proneness to stripping are realized, anisotropismis prevented, and high strength and quality stability are realized. The structure with the grooves is easy to shape and can be bent along any directions to form the grooves, and low aluminum materialconsumption, light weight, thinness and low manufacturing cost are realized.

The invention discloses an aluminum alloy corrugated board, and relates to the technical field of aluminum alloys. The aluminum alloy corrugated board comprises a first aluminum alloy layer, a first corrugated core layer, a second aluminum alloy layer, a second corrugated core layer and a third aluminum alloy layer which are sequentially laminated, wherein the first corrugated core layer and the second corrugated core layer are arranged in an interlaced manner. The above design mode can enhance the performance strength of the corrugated board, prevent anisotropy and reduce the probability of peeling of a core and a board.

The invention discloses a randomly-distributed short tungsten fiber reinforced CuW composite. The randomly-distributed short tungsten fiber reinforced CuW composite is prepared from following raw materials in percent by mass including: 9.5%-30% of Cu powder, 60%-90% of W powder and 0.5%-15% of short tungsten fibers, wherein the sum of the mass percents of the components is 100%. The mechanical performance such as stretching, compression and frictional wear of the composite is remarkably improved. The invention further provides a preparation method of the composite. The preparation method specifically includes the steps that 1, 9.5%-30% of Cu powder, 60%-90% of W powder and 0.5%-15% of short tungsten fibers are weighed according to the mass percents, wherein the sum of the mass percents ofthe components is 100%; 2, the components are mixed; 3, a composite blank is prepared; 4, the composite blank is subjected to hot-pressed sintering; and 5, the composite blank obtained after hot-pressed sintering in S4 is subjected to copper infiltration. By means of the method, the comprehensive mechanical performance of the composite can be remarkably improved.

The invention discloses a metal selective melting forming method based on laser spot patterning output. The method comprises the steps that firstly, laser beams are subjected to spot pre-modulation, and obtained initial seed light is incident into a spatial light modulator to be processed; secondly, a preprocessed metal model slice is input into a control system of the spatial light modulator, thecontrol system drives the spatial light modulator, and the incident initial seed light is modulated into spot patterning seed light in the shape corresponding to the metal model slice to be output; and thirdly, the spot patterning seed light output by the spatial light modulator is subjected to power amplification, the amplified light beams are projected to a base plate paved with metal powder, and metal powder area array sintering is achieved by adjusting the power density of laser projected to the base plate. According to the metal selective melting forming method, anisotropy on a metal workpiece slice layer due to the fact that path planning is too regular is avoided to the maximum degree, and accordingly the forming quality is improved.

The invention is suitable for the technical field of additive manufacturing materials, and provides titanium alloy powder with endogenous nano composite ceramic particles and a preparation method andapplication thereof. The preparation method comprises the following steps that a titanium-based mother alloy is placed in a vacuum environment to be smelted, and a molten alloy is obtained; an aluminum-based intermediate alloy containing nano TiC and nano TiB2 is added into the molten alloy, homogenization treatment is carried out, and then casting molding is carried out to obtain a casting blank;and the casting blank is made into powder through a plasma rotating electrode atomization method or a gas atomization method, screening is conducted, and the nano TiC and nano TiB2 reinforced titanium alloy powder is obtained. According to the preparation method, by adding the nano TiC and the nano TiB2, the isometric crystal proportion of the titanium alloy powder through additive manufacturingparts can be remarkably increased, columnar crystals are reduced, and the structure uniformity after additive manufacturing is greatly improved, so that the anisotropy phenomenon can be avoided, the crack forming tendency is relieved, and the strength and plasticity of additive manufacturing metal products are improved.

The invention provides a powder coating leveling agent and a preparation method thereof. The powder coating leveling agent is made by copolymerizing 5-40% by weight of a vegetable oil, 40-95% by weight of alkyl acrylate monomer, 0-20% by weight of alkyl methacrylate monomer by conventional dropwise polymerization; this vegetable oil is one of or a mixture of more than one of soybean oil, palm oil, rapeseed oil and castor oil, the alkyl acrylate monomer includes linear, branched or cyclic aliphatic monohydric alcohol ester with 2-22 carbon atoms, the alkyl methacrylate monomer includes linear, branched or cyclic aliphatic monohydric alcohol ester with 1-12 carbon atoms. The powder coating leveling agent of the invention has the advantages of greenness, low cost, high hydrophobicity, good leveling performance, heat resistance, acid and alkali resistance, good waterproof performance and the like, the preparation method is simple, and the powder coating leveling agent is applicable to powder coatings or solvent coatings.

The invention discloses a heat accumulating type electric heater with a heat accumulator formed by casting. The electric heater comprises a outer shell body, wherein a grating cover is arranged abovethe outer shell body, a skirt base is arranged below the outer shell body, at least one fan is arranged at the bottom of the skirt base; the heat accumulator is arranged in the outer shell body, the heat accumulator is a cast-formed solid heat accumulating material, a plurality of air flow channels are uniformly arranged in the heat accumulator at intervals, the lower ends of the air flow channelscommunicate with the interior of the skirt base, the upper ends of the airflow channels communicate with the interior of the grating cover, and an electric heater is arranged between every two adjacent airflow channels. According to the heat accumulating type electric heater, the heat accumulator, the electric heater and the heat preservation layer are in a totally-closed structure and are isolated from outside air, so that metal oxidation can be prevented, the service life of related components is prolonged, the closed structure becomes a thermodynamic closed system, the heat exchange is carried out with the outside, no matter and mass exchange exists, zero emission of the system is achieved, the environment-friendly effect is achieved, the water and the water vapor or the particles cannot be immersed, and a relatively high safety protection grade is achieved.