384results about How to "Avoid introducing" patented technology

The invention discloses a method for preparing a single-layer tungsten diselenide nanoband based on a space confinement strategy. By changing the flow and the growth time of hydrogen, effective control on the width and the thickness of a nanoband can be realized. The method comprises the following steps: uniformly spraying tungsten trioxide powder to one substrate, then covering the substrate by the other substrate, and forming micro reaction space which is of a 'sandwich'-like structure. Growth of a tungsten diselenide nanoband is carried out by utilizing a constant-pressure chemical vapor deposition method; physicochemical characteristics of a one-dimensional transition metal chalcogenide strongly depend on suspension key types on the edge of the one-dimensional transition metal chalcogenide, metallic properties are displayed by an ultranarrow band, and conversion from the metallic properties to semiconductor properties can be displayed from the edge to the center of a wider band; the tungsten diselenide nanoband is widely applied to micro-nano photoelectric devices due to the special property; industrial production of the tungsten diselenide nanoband can be realized through an experimental method of the invention.

The invention relates to self-healing double-layer hydrogel for promoting healing of diabetic wounds as well as a preparation method and application of the self-healing double-layer hydrogel, and belongs to the technical field of medical materials of surgical supplies containing macromolecular materials. The hydrogel comprises an inner layer and an outer layer, the inner layer is self-healing hydrogel in which microalgae cells are uniformly distributed, and the outer layer is self-healing hydrogel in which metal ion-humic acid coordination nanoparticle compounds are uniformly distributed, the self-healing hydrogel is formed by self-crosslinking of a macromolecular polymer containing an aldehyde group and a macromolecular polymer containing an amino group. The hydrogel provided by the invention has excellent biocompatibility, adhesion and self-healing performance, can meet the requirements of actual production and application, and has a relatively great application prospect as a dressing for chronic diabetes wounds; and the preparation process has the characteristics of simplicity in operation, low cost and mild reaction conditions, and is suitable for large-scale popularization and application.

The invention discloses a prompt learning and alignment strategy-based dialogue recommendation model training method and a dialogue recommendation method. The training method comprises the following steps: inputting a dialogue history and a knowledge graph into a pre-training language model and a graph convolutional network to respectively obtain feature embedding of a text and an entity; performing semantic alignment on the features through multi-granularity contrast learning, and performing semantic fusion by using a linear cross interaction method to obtain multi-modal feature embedding; pre-training a soft prompt template shared by multiple tasks by using the features, and guiding a dialogue model to complete dialogue generation and recommendation tasks; according to the method, the semantic consistency between the models can be effectively improved, the context understanding ability of the pre-trained language model in the subtask of the dialogue recommendation system is remarkably enhanced, and the multi-granularity contrast learning is carried out, so that the multi-granularity contrast learning efficiency is improved. And a semantic gap between the text information and the knowledge graph is effectively reduced.

The invention discloses a continuous-discontinuous numerical simulation method considering a rock mass thermal coupling problem, and the method comprises the steps: dividing a simulation region into a potential damage region and a non-damage region, and carrying out the grid division of the simulation region; then generating a thermal calculation node system and a force calculation node system for analog calculation, wherein a mapping relationship exists between the thermal calculation node system and the force calculation node system; jointing units are arranged on the grid boundary of the potential damage area, and the rock mass fracture process is simulated through damage of the jointing units; the simulation process is decomposed into a plurality of calculation steps, the heat conduction process and the mechanical calculation process in each calculation step are solved in sequence, whether the joint unit is damaged or not is judged according to the deformation and stress state of the joint unit, the mapping relation is updated until the last calculation step is finished, and the thermal fracture process simulation of the rock mass is completed. According to the method, artificial heat transfer parameters can be prevented from being introduced in the heat conduction simulation process, the fracture evolution rule of the local area of the rock mass is researched in a targeted mode, the calculation cost of the model is reduced, and the dynamic fracture process in the rock mass thermal coupling problem is effectively simulated.

The invention discloses a Staphylococcus edaphicus H3, the preservation number of the Staphylococcus edaphicus H3 in Guangdong Microbial Culture Collection Center is GDMCC No: 64958, the strain H3 is applied to fermentation of meat products without nitrite, the Staphylococcus edaphicus H3 can promote color development of the meat products, and the Staphylococcus edaphicus H3 has relatively strong oxidation resistance, can effectively inhibit lipid peroxidation, and can be used for preparing the meat products. The staphylococcus aureus H3 can produce polysaccharide, the polysaccharide also plays an anti-oxidation role in a meat product processing process and is beneficial to maintenance of meat color, the strain H3 is inoculated to ferment sausages, the nitrite content in the sausages is obviously reduced, the hardness, cohesiveness, elasticity and chewiness of the sausages are improved, the taste of the sausages is richer, the delicate flavor is increased, and the sausages are more delicious. The strain H3 has no blood coagulation and hemolysis effects, is safe and reliable as a food additive, and is suitable for industrial production and market popularization and application.

The invention discloses a preparation method of a self-humidifying membrane electrode of a proton exchange membrane fuel cell, relates to a preparation method of a membrane electrode, and aims to solve the technical problem of poor performance of the conventional self-humidifying membrane electrode. The method comprises the following steps: 1, synthesizing a COFs material by using 2, 4, 6-triformyl phloroglucinol and 2, 5-diaminobenzene sulfonic acid through a two-phase method; 2, preparing slurry a by using a Pt / C catalyst and a perfluorosulfonic acid ionomer solution; preparing self-humidifying catalyst layer slurry b from a COFs material, a Pt / C catalyst and a perfluorosulfonic acid ionomer solution; and 3, coating the slurry a on the anode surface of the proton exchange membrane, and coating the slurry b on the cathode surface to obtain the self-humidifying membrane electrode. According to the electrode, H2 / O2 is used as fuel, and the power density is 756.3 mW / cm < 2 > under the relative humidity of 20%; h2 / air is used as fuel, the power density is 437.8-879.7 mW / cm < 2 > under the relative humidity of 50%, and the material can be applied to the field of fuel cells.

The utility model provides an automatic fluid demagnetizing device which comprises two rodless air cylinders arranged in parallel, a fixing frame is fixedly connected to a sliding block of one rodless air cylinder, more than one magnetic bar is fixedly connected to the fixing frame, a scraping plate is fixedly connected to a sliding block of the other rodless air cylinder, and the scraping plate is fixedly connected to the other rodless air cylinder. Scraping gaskets with the number corresponding to that of the magnetic bars are fixedly installed on the scraping plate, and the magnetic bars penetrate through the scraping gaskets. The original position of the demagnetizing device can be arranged in fluid equipment, so that the introduction of magnetic substances in the environment can be effectively avoided; meanwhile, an automatic control function is added to the demagnetizing device, manual operation can be achieved, the demagnetizing device can also run automatically, the functions of automatic production, unmanned inspection and the like are achieved, and therefore production efficiency is improved.

The invention provides a preparation method of pressureless sintered boron nitride composite ceramic, and relates to the technical field of ceramic composite material preparation. The method comprises the following steps: carrying out surface modification on boron nitride whiskers by using ethanolamine, and activating hexagonal boron nitride powder in a ball milling tank by using an alkaline solution; the preparation method comprises the following steps: uniformly mixing the boron nitride powder and the boron nitride powder in a mixing tank, carrying out cold isostatic pressing to obtain a cold-pressed green body, and carrying out high-temperature calcination on the cold-pressed green body in an inert atmosphere to finally obtain the boron nitride composite ceramic. According to the invention, the physical property characteristics of the boron nitride whisker are fully utilized, and the boron nitride whisker can be fully combined with the hexagonal boron nitride powder subjected to surface activation during calcination through further chemical surface modification, so that relatively high mechanical strength can be realized only by using one phase of boron nitride on the premise of not introducing other sintering aids; the method has the characteristics of high product purity, low production cost and high mechanical strength.

The invention discloses a preparation method of a defective graphene negative electrode for a lithium battery, which comprises the following steps: grinding natural graphite into powder, carrying out graphite modification by irradiation of a high-current pulse electron beam, mixing with a conductive agent and a binder to prepare slurry, and coating the slurry on a metal foil to prepare the defective graphene negative electrode for the lithium battery. Natural graphite is modified through high-current pulse electron beam irradiation, obvious expansion deformation occurs on the surface of the natural graphite, defects are generated on a graphite structure, mutual stripping between graphite layers is achieved, the whole surface of the graphite is in a hairy wrinkle form, the structure is almost transparent, and the storage capacity and the cycling stability are obviously improved; the obtained defective graphene negative electrode material provides more channels for lithium ion diffusion, the ion diffusion path is effectively shortened by internal gaps, and a physical method is adopted, a specific reducing agent, an oxidizing agent or other intermediate media do not need to be used, and introduction of impurities is avoided.

The invention relates to a forming die, and particularly discloses a rare earth permanent magnet powder compression forming die which comprises an upper die assembly, a lower die assembly and a filling mechanism, and the lower die assembly comprises a bearing disc, a driving mechanism and a lower die body; a plurality of material returning holes are formed in the bearing disc; the driving mechanism is in transmission connection with the bearing disc; the lower die body is provided with forming holes with the same number as the material returning holes, the lower die body is rotationally fixed above the bearing disc, a one-way transmission mechanism is arranged between the lower die body and the bearing disc, and the bearing disc and the lower die body rotate relatively, so that the material returning holes and the forming holes are distributed oppositely or in a staggered mode; a pressing head is arranged in the upper die assembly, and the filling mechanism is composed of a filling head and a feeding pipe. Pressure is applied to pressing and demolding of the green body through the upper mold assembly, an ejection mechanism and a power device do not need to be independently arranged for demolding, and the overall structure of the profiling equipment is simplified. And an upper-inlet and lower-outlet mode is adopted for work, contact between the blank and the magnetic powder is avoided, the surface cleaning work of the blank is omitted, the machining efficiency is improved, and the process cost is saved.

The utility model aims to provide the cleaning line for slicing the silicon wafer, which is simple in structure, energy-saving, environment-friendly and low in cost. According to the utility model, the cleaning part comprises the bubble water generator, the cleaning part comprises the plurality of cleaning tanks, and the silicon wafer slices are sequentially placed in the plurality of cleaning tanks to be cleaned; the plurality of cleaning tanks are sequentially a primary cleaning tank (1), an ultrasonic normal-temperature cleaning tank (2), a normal-temperature bubble water cleaning tank (3), a bubble water soaking cleaning tank (4), a first weak base water cleaning tank (5), a second weak base water cleaning tank (6) and a plurality of pure water rinsing cleaning tanks which are sequentially arranged; the bubble water generator inputs bubble water into the normal-temperature bubble water cleaning tank (3) and the bubble water soaking cleaning tank (4), and quantitative weak base water is added into the first weak base water cleaning tank (5) and the second weak base water cleaning tank (6). The utility model is applied to the field of cleaning equipment.

The invention relates to a flight calibration method and system for structural parameters of a star sensor and an inertial unit, and the method comprises the following steps: setting parameters and environmental parameters of the star sensor and the inertial unit, and setting an initial state of a structural parameter deviation estimator; after the inertial unit and the star sensor output data, performing time propagation on estimation values and estimation covariance of constant zero offset, zero offset drift and structural parameter deviation; calculating attitude increments of the inertial unit and the star sensor by using the angular velocity and star observation information, and constructing a measurement equation of structural parameter deviation; solving a corresponding regularization least square problem by using a regularization robust filtering framework, and completing estimation value updating and estimation covariance updating of constant value zero offset, zero offset drift and structure parameter deviation; and after the stable estimated value of the structure parameter deviation is obtained, the structure parameters are compensated. According to the method, high-precision structural parameter calibration of the star sensor and the inertial unit can be realized, and complicated astronomical-ground coordinate conversion can be carried out without the aid of time service positioning information.

The present invention provides a self-scaling and self-sterilizing circulating cooling water system, comprising an electrochemical electrolysis device arranged on a pipeline of the circulating water system; the electrochemical electrolysis device is used to convert chloride ion-containing water into H + and oxidizing chlorine species, and then the H-rich + The system of the present invention directly connects the electrochemical electrolysis device to the original circulating cooling water system, and utilizes the action of the electrochemical electrolysis device to generate H-rich + and oxidizing chlorine species in water and input the water into the pipeline for scale inhibition and sterilization of the water, replacing the traditional technical means of adding sulfuric acid, scale inhibitors and bactericides into the circulating water system.

The invention discloses an adjustable wide-adaptation MOSFET turn-off gate drive circuit and a drive method, and relates to the field of power electronics, and the drive circuit matches parasitic parameters of a to-be-controlled power MOSFET through parameter configuration so as to improve the applicability. In the turn-off process of the to-be-controlled power MOSFET, the circuit controls the grid voltage to be rapidly decreased at the stage higher than the Miller platform, to be kept at the Miller platform voltage during the Miller platform, to be linearly decreased at the stage from the Miller platform to the threshold voltage, and to be rapidly decreased below the threshold voltage. Through continuous fine control of grid voltage, drain-source side voltage and current track regulation and control are realized. The problems that according to an existing turn-off driving circuit, grid voltage is difficult to finely regulate and control in the turn-off process of a power MOSFET device, voltage and current tracks on the drain side and the source side of the power MOSFET cannot be finely regulated and controlled independently, the targets of low voltage overshoot and low turn-off loss are difficult to meet in the turn-off process at the same time, limited application of the power MOSFET device is difficult to achieve, and the turn-off efficiency of the power MOSFET device is low are solved. And the high power density requirement of the power electronic device is difficult to meet.

The invention belongs to the technical field of waste recycling, and particularly relates to a method for recycling nitric acid in acid yellow water based on nitration. The method for recovering nitric acid based on nitration acid yellow water comprises the following steps: stirring nitration acid yellow water and toluene or nitrotoluene and other organic extraction agents in a mixer, adding a certain amount of sulfamic acid, fully extracting, standing for layering, and removing the organic extraction agents through a stripping tower to obtain the nitric acid. The acid yellow water after extraction-steam stripping is sent to a nitric acid absorption-concentration tower to obtain concentrated nitric acid, and the concentrated nitric acid is recycled to a nitration reaction unit as a raw material.

The invention discloses an advanced treatment agent for textile printing and dyeing wastewater and a treatment method. The advanced treatment agent comprises a component A and a component B, the component A comprises modified graphene oxide and an enzyme treatment agent; the component B comprises magnesium aluminum silicate, hydroxyapatite, hydroxypropyl methyl cellulose and chitosan, and the hydroxyapatite is coated with the magnesium aluminum silicate to form a core-shell structure. By adopting a modified graphene oxide immobilized enzyme structure, harmful components in water can be effectively adsorbed, so that the effect of greatly improving sewage purification is achieved, and meanwhile, the adsorption effect of the harmful components can be further improved by matching with aluminum-magnesium silicate coated hydroxyapatite, hydroxypropyl methyl cellulose and chitosan; meanwhile, bonding with the modified graphene oxide is beneficial to agglomeration and flocculation of substances, so that the flocculation capacity is improved, and floc separation is facilitated.

The invention discloses an induction culture medium for preparing human umbilical cord mesenchymal stem cell exosomes and application of the induction culture medium, and relates to the technical field of exosome culture. The additive is prepared from the following components: 0.8 to 1.5 percent of ITS, 0.03 to 0.05 percent of a luteolin extract, 0.04 to 0.06 percent of a herba taraxaci extract, 0.02 to 0.04 percent of a radix ginseng extract, 0.03 to 0.05 percent of resveratrol, 0.01 to 0.03 percent of vitamin C, 0.03 to 0.05 percent of a pimpinella thellungiana extract, 0.01 to 0.03 percent of a rhizoma dioscoreae extract and 0.01 to 0.02 percent of sodium citrate; the induction culture medium provided by the invention not only can avoid introduction of exogenous substances and reduce the pollution risk, but also can promote proliferation of stem cells and effectively induce synthesis and exosome secretion of a large number of human umbilical cord mesenchymal stem cells.

The invention relates to a cross-Kubernetes cluster service access method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: respectively setting an Ingress Nginx controller in a service providing cluster and a service consumption cluster; using a NodePort mode to set an access path used for providing use permission of an Ingress Nginx controller for an external cluster of the service providing cluster or the service consuming cluster; a Kube-apiserver is used to monitor a service updating state with an annotation mark in the service providing cluster; when it is determined that the new service appears in the service providing cluster, an Ingress access rule is created in the service providing cluster, and the Ingress access rule is used for determining a target service consumption cluster with the access permission; and starting an IP address resolution plug-in in the target service consumption cluster, and accessing the new service through a domain name access mode. By adopting the method, the new service limitation can be exposed to the specified cluster, and the cross-cluster service access efficiency and reliability are improved.

The invention relates to a preparation method of lithium fluoroborate containing unsaturated bonds, and belongs to the technical field of lithium ion battery additives. The preparation method comprises the following steps: carrying out reaction on organic acid lithium containing unsaturated bonds and boron trifluoride gas in a solvent at a low temperature of-10 to 0 DEG C, and carrying out solid-liquid separation to obtain a lithium fluoroborate crude product containing unsaturated bonds; the solvent is a poor solvent of lithium fluoroborate containing unsaturated bonds. According to the method, boron trifluoride gas is used as a fluorine reagent, so that introduction of water is avoided; the method has the advantages of simple operation, high product quality, high yield, low cost, full utilization of raw materials, reduction of the generation of three wastes, and suitableness for large-scale production. The yield of the obtained product can reach 96% or above, and the purity can reach 99% or above.

The utility model relates to the technical field of bacterial culture devices, in particular to a pH-value-adjustable bacterial culture device, which comprises a culture tank provided with a closing cover, and further comprises a temperature control base arranged below the culture tank and used for adjusting bacterial culture temperature; the illumination ring is arranged on the temperature control base, sleeves the culture tank body and is used for providing bacterial culture illumination; the at least one adjusting unit comprises an adjusting liquid tank, and the adjusting liquid tank is communicated and connected with the culture tank through a liquid conveying pipe; a liquid pressing plate which vertically ascends and descends along the inner wall of the adjusting liquid tank is arranged in the adjusting liquid tank, and the liquid pressing plate is used for pressing the pH adjusting liquid into the adjusting liquid tank; adjusting liquid can be conveyed into the culture tank through the arranged adjusting unit so as to adjust the pH of the culture environment, the culture tank does not need to be opened, the stability of culture conditions can be kept, and other pollution media are prevented from being introduced when the culture tank is opened and the adjusting liquid is dropwise added; meanwhile, the temperature control base and the illumination ring arranged in the device can provide proper illumination and temperature for bacterial culture.

The invention relates to the technical field of preparation of hexagonal boron nitride ceramic materials, in particular to a preparation method of a hexagonal boron nitride-based ceramic crucible. The hexagonal boron nitride combined crucible with adjustable porosity and low volatile matter content is prepared by a method of ball milling, hot pressed sintering, machining and heat treatment, so that the purposes of adjusting the porosity rate and improving the mechanical property of the hexagonal boron nitride ceramic material are achieved. After the blank material is prepared, the hexagonal boron nitride crucible with the required specification can be directly prepared by adopting a linear cutting and machining method according to the specification or requirement of the actually used crucible. The porosity-adjustable hexagonal boron nitride combined crucible solves the problem that the service life of an existing crucible prepared from pure hexagonal boron nitride ceramic is short due to low material strength.

The invention discloses a preparation method of a tungsten-nickel target material for electrochromic intelligent glass, and relates to the technical field of tungsten-nickel target materials, and the preparation method comprises the following preparation steps: uniformly mixing N powder and W powder to obtain W-N mixed powder; the W-N mixed powder is put into a graphite mold to be flatly laid; putting the graphite grinding tool filled with the W-Ni mixed powder into a vacuum hot-pressing sintering furnace, firstly increasing the pressure to 6-10MPa, maintaining the pressure for 10-15min, and then releasing the pressure; the method comprises the following steps: vacuumizing a vacuum hot-pressing sintering furnace to below 5Pa, then carrying out three-stage heating to 1250-1300 DEG C, carrying out heat preservation for 30-60 minutes after heating is finished, then carrying out two-stage pressurization to 35-40 MPa, carrying out heat preservation and pressure preservation for 90-150 minutes, and then cooling to 100-200 DEG C along with the furnace to obtain a WNi alloy target blank; the temperature field is uniform through three-section heating, radial shrinkage is inhibited through pressure supplement, and finally, uniform and fine grain structures are obtained while the density of the target material is improved through a two-section pressurizing mode.

The invention discloses a method for synthesizing battery-grade lithium phosphate from electrolytic aluminum overhaul slag, which comprises the following steps: crushing and levigating the electrolytic aluminum overhaul slag to obtain slag powder with preset particle size; sequentially adding a preset amount of concentrated sulfuric acid and alkali into the slag powder to remove iron, aluminum, calcium and magnesium impurities, and filtering to obtain a monovalent ion solution containing lithium sulfate; the method comprises the following steps: heating a monovalent ion solution containing lithium sulfate to 80-100 DEG C, adding a preset amount of sodium phosphate for reaction, and filtering to obtain crude lithium phosphate precipitate and precipitate mother liquor; performing primary pure water stirring washing on the crude lithium phosphate precipitate, then performing dilute polyacid solution stirring washing, finally performing secondary pure water stirring washing, and drying to obtain a lithium phosphate product with low sodium sulfate content; and concentrating and crystallizing the precipitation mother liquor to obtain a sodium sulfate byproduct. The invention aims to remove corresponding impurities in the lithium phosphate product synthesized from the electrolytic aluminum overhaul slag with high cost performance.

The invention discloses a gas compressor rotor blade milling blade body clamp and a blade body milling method thereof, and belongs to the technical field of aero-engine gas compressor blade machining. The clamp comprises a connecting disc, a supporting block, a positioning assembly A, a positioning assembly B and a clamping mechanism, the supporting block is arranged on the end face of one end of the connecting disc, the positioning assembly A and the positioning assembly B are both arranged on the supporting block, and the clamping mechanism is movably connected with the positioning assembly B and the supporting block. Two profiling check blocks are symmetrically and detachably connected to the inner side of the clamping mechanism. When the shapes or sizes of the tenons of the to-be-machined compressor rotor blades are different, the to-be-machined compressor rotor blades can be positioned and clamped only by replacing the profiling check blocks, the use flexibility of the clamp is remarkably improved, the clamp does not need to be aligned again, human errors are prevented from being introduced in the clamp replacing process, and the machining efficiency is improved. The machining cost of the clamp is reduced, and the alignment time of the clamp is saved.

The invention discloses an operational-amplifier-free band-gap reference voltage circuit with base compensation and high-order compensation. The operational-amplifier-free band-gap reference voltage circuit comprises a starting module, a band-gap reference core module, a base current compensation module, a high-order logarithmic compensation module and a high-temperature zone segmentation compensation module. Wherein the starting module, the band-gap reference core module, the base current compensation module, the high-order logarithm compensation module and the high-temperature zone segmentation compensation module are all connected with a power supply VDD and are also all grounded; the starting module, the band-gap reference core module, the base current compensation module, the high-order logarithm compensation module and the high-temperature zone segmentation compensation module are connected in sequence, and the high-order logarithm compensation module is further connected with the starting module and the band-gap reference core module. The precision and the stability of the band-gap reference voltage circuit can be improved, and the reference output temperature drift is remarkably reduced.

The invention relates to a carbonaceous reducing agent pellet with low-order non-caking coal as a main body and application, and belongs to the technical field of efficient and clean utilization of resources. The carbonaceous reducing agent pellets are mainly prepared from low-order non-caking coal as a main body, the main body is matched with a composite organic binder, silica fume and a reinforcing agent, the mixture is subjected to compression molding and then placed in a sintering furnace to be roasted at the temperature of 450-650 DEG C in a protective atmosphere, and furnace cooling is conducted till the carbonaceous reducing agent pellets are obtained. The pellet developed by the invention has the characteristics of high fixed carbon content, high pellet strength, high breakage resistance, good static spheroidization index, low content of introduced impurities and high reaction activity, so that the pellet is particularly suitable for industrial silicon smelting. The low-order non-caking coal is applied in a large proportion, the micro-silicon powder produced by the submerged arc furnace is recycled, and the method is clean and environment-friendly, can be completely used for smelting and production of industrial silicon, reduces smelting unit consumption and production cost, and can replace or partially replace charcoal to become a carbonaceous reducing agent for smelting of industrial silicon.

The invention relates to a carrier three-dimensional attitude determination method based on night polarized light field double-vector characteristics, which comprises the following steps: acquiring night sky polarized light field information, and acquiring an image plane coordinate system neutral point coordinate and a moon coordinate based on polarization distribution mode neutral surface characteristics; based on an imaging model, inversely solving a polarization neutral point vector and a moon vector under a carrier coordinate system, and further calculating a carrier system neutral surface normal vector; obtaining a moon vector under the navigation system according to the time information and the geographic position information, and calculating to obtain a normal vector vector of a neutral surface of the navigation system by using a zenith direction vector; constructing an orthogonal coordinate system by using the corresponding moon vector and the normal vector in the carrier system and the navigation system respectively; and calculating an attitude conversion matrix based on the two orthogonal coordinate systems so as to obtain a conversion relation between the carrier system and the navigation system and obtain a three-dimensional attitude angle. According to the invention, autonomous attitude determination based on the sky polarized light field under the condition of no external input is realized, an external error source is removed, and autonomy is improved.

The invention relates to the technical field of metallurgy, and discloses a preparation method of a low-nitrogen-content and low-impurity high-purity vanadium-aluminum alloy, which comprises the following steps: step 1, controlling the purity, granularity and content of raw materials; 2, baking the raw materials and mixing the raw materials; step 3, charging; step 4, smelting; step 5, coarse crushing; sixthly, sand blasting treatment is conducted; and step 7, crushing, refining, screening, detecting and packaging. According to the method, the content of the added aluminum oxide cooling material is controlled, the vacuum environment is applied to the smelting process, argon is introduced until the pressure in the furnace is-0.08 MPa after vacuumizing is stopped, volatilization of elements in the alloy is reduced, and the beneficial effect that the loss of reaction heat and the influence of impurities such as oxygen and nitrogen in air on the purity of the alloy are avoided is achieved.

The invention belongs to the technical field of powder metallurgy, and particularly relates to a preparation method of high-uniformity molybdenum-rhenium alloy powder. In the prior art, no matter a dry method or a wet method is adopted for preparing molybdenum-rhenium alloy powder, the problem that metal rhenium is unevenly distributed in the molybdenum-rhenium alloy powder generally exists, and the performance of molybdenum-rhenium alloy is directly affected. The invention discloses a preparation method of high-uniformity molybdenum-rhenium alloy powder. The preparation method comprises the following steps: firstly, adding ammonium molybdate, ammonium perrhenate and a dispersing agent into deionized water, heating and dissolving to obtain a suspension; then, the suspension is subjected to spray drying in a spray drying tower, and dry powder is obtained; and finally, the dry powder is subjected to roasting and two-step reduction in a tubular furnace, and the high-uniformity molybdenum-rhenium alloy powder is obtained. According to the preparation method, the dispersing agent is added in the dissolving process, the problem that ammonium molybdate or ammonium perrhenate is non-uniformly crystallized and separated out when water is removed in the spray drying process is solved, the uniformity of the molybdenum-rhenium alloy powder is improved, and the quality of the molybdenum-rhenium alloy powder is improved.

The invention discloses modified ferromanganese ammonium phosphate, modified ferromanganese pyrophosphate and a preparation method and application of the modified ferromanganese ammonium phosphate and the modified ferromanganese pyrophosphate, and belongs to the technical field of battery materials. Adding an oxidizing agent and regulating the pH to form ammonium ferric phosphate, and carrying out ion exchange reaction on the ammonium ferric phosphate, manganese salt and doped metal salt to exchange iron elements in the ammonium ferric phosphate to form metal doped ammonium manganese ferric phosphate; meanwhile, the exchanged iron ions continuously react with phosphate radicals generated by converting manganese ions, doped metal ions and ferrous dihydrogen phosphate into iron phosphate in the system to form metal-doped manganese iron ammonium phosphate, so that manganese, iron and doped metal atoms can be uniformly distributed in a precursor crystal lattice at an atomic level; the generation of a non-solid solution impure phase and a solid solution phase with a non-target manganese-iron ratio and the introduction of anion impurities are effectively avoided, so that the ratio of metal to phosphorus in the metal-doped ammonium manganese iron phosphate obtained by the reaction is less than 1, and the electrochemical performance of the modified lithium manganese iron phosphate is favorably improved when the metal-doped ammonium manganese iron phosphate is applied to the positive electrode material.