24775 results about "Graphite" patented technology

The invention relates to a method for preparing a lithium iron phosphate / carbon composite material of a lithium ion battery, which belongs to the technical field of lithium ion batteries. The method for preparing the lithium iron phosphate / carbon composite material of the lithium ion battery comprises the following steps of: 1) preparing a suspending graphene-dispersed aqueous solution system, namely, crushing graphite to 1 to 5 microns, adding the crushed graphite into distilled water or purified water, adding 0.1 to 5 percent of surfactant, heating with stirring the mixed solution to 180 to 250 DEG C in a sealing way, performing stirring for 2 to 6 hours and reducing the temperature; 2) crushing lithium iron phosphate to the particle size of 1 to 5 microns, adding the crushed lithium iron phosphate into the distilled water or the purified water, adding with stirring 0.01 to 1 percent of coupling agent, performing uniform stirring, adding the graphene-dispersed aqueous solution, and performing stirring and filtration; and 3) vacuum-drying solid powder obtained by the filtration, and calcinating the dried solid powder for 2 to 12 hours to obtain the graphene-coated lithium iron phosphate cathode material. The method has the advantages of simple process, high material performance, high conductivity, high bulk density, high compacted density and the like.

The invention provides a low-voltage cable, and relates to the technical field of cables, the low-voltage cable comprises a conductor layer, a support layer, a shielding layer and a sheath layer, the conductor layer is composed of multiple strands of fractal stranded conductors, and each fractal stranded conductor comprises an inner-layer superfine silver-plated copper wire, a middle-layer copper-clad aluminum wire and an outer-layer nickel-plated copper alloy wire; the supporting layer wraps the conductor layer and comprises an inner supporting layer, a dynamic framework layer and an outer restraint layer, the inner supporting layer is an obliquely wound aramid fiber woven belt, the dynamic framework layer is formed by alternately arranging shape memory polymers and carbon fiber composite belts, and the outer restraint layer is a spirally wound silica gel-glass fiber composite rope. The shielding layer comprises a tinned copper wire woven mesh; the sheath layer is a thermoplastic polyurethane matrix, a microcapsule self-repairing agent is dispersed in the thermoplastic polyurethane matrix, a microcapsule comprises a siloxane prepolymer, and the thermoplastic polyurethane matrix further comprises graphene nanosheets. Through collaborative design of the fractal stranded conductor layer, the dynamic skeleton support layer, the shielding layer and the self-repairing sheath, comprehensive improvement of cable performance is realized.

The invention relates to the technical field of process optimization, and discloses an optimization method and system for a graphite sagger compression molding process. The method comprises the following steps: determining and analyzing particle size distribution, specific surface area, porosity and viscosity-temperature characteristics of graphite powder and a binder to obtain raw material characteristic parameter data; modeling is conducted on the migration behavior of the binder and the deformation characteristic of the graphite powder in the pressing process, a material rheological model is obtained, meanwhile, a multi-point pressure sensor system is arranged on the surface of a pressing mold, and target pressure data are collected; constructing a pressure distribution feature vector and a material flow state prediction result; performing adaptive adjustment on the initial pressing parameters to obtain a segmented pressure curve and a local pressure compensation strategy; and performing multi-objective optimization on the graphite sagger pressing path to obtain an optimal pressing process parameter combination. The method is combined with material flow state prediction, accurate control over the pressing process is achieved, and the intelligent level of the graphite sagger pressing forming technology is improved.

The invention relates to the field of electric heating materials, and provides a graphene-based heating coating and a preparation method thereof. The coating is prepared from functionalized graphene, a surface modified bismuth telluride nanobelt, polyaniline, bisphenol A epoxy acrylate, polyurethane acrylate, a dispersing agent, a flatting agent, a silane coupling agent, a defoaming agent and a propylene glycol methyl ether acetate / N-methyl pyrrolidone mixed solvent. The functionalized graphene is obtained by modifying a hyperbranched polyolefin-acryloyl-POSS copolymer, and carrying out ultrasonic stripping, centrifugal separation, gradient washing and vacuum drying; the surface-modified bismuth telluride nanobelt is modified by an amino silane coupling agent, so that the interfacial compatibility is improved. The preparation method comprises the steps of solvent premixing, nanofiller dispersion, ultrasonic homogenization, coupling agent modification, ultraviolet curing and thermocuring. The heating coating provided by the invention has high conductivity, excellent thermal stability and adhesive force, and can be widely applied to heating electric appliances and intelligent temperature control equipment.

The invention relates to a waste lithium iron phosphate battery recycling method, in particular to a graded recycling method for lithium, iron, phosphorus and graphite in a waste lithium iron phosphate battery, and belongs to the technical field of lithium ion batteries and resource recycling of the lithium ion batteries. According to the method, the mode that oxidizing roasting and selective leaching are combined is adopted, the leaching rate and selectivity of lithium are effectively improved, the leaching rate of the lithium element is close to 100% under the optimized condition, and limit recovery of the lithium element is achieved; meanwhile, aiming at the problem that iron and phosphorus in the leaching residues are difficult to utilize, a wet ball milling and secondary acid leaching method is combined, phosphorus and iron elements are separated from negative electrode graphite firstly, and graded recovery of iron, phosphorus and graphite is achieved. According to the method, the high recovery rate of lithium is realized, and meanwhile, high-added-value products such as ferric oxide and sodium phosphate are prepared by efficiently recovering ferric phosphate.

It is disclosed new conducting and stretchable hydrogels and “one-pot” process to making them from natural and eco-friendly components, including gelatin, chitosan, and glycerol. Various conducting materials, such as poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), thermally reduced graphene (TRG), or MXene are introduced in the hydrogels to enhance their conductivity. The resulting conducting hydrogels exhibit remarkable robustness, do not require crosslinking agent, and possess a unique thermo-reversible property, simplifying the fabrication process and ensuring enhanced long-term stability. Moreover, their fabrication is sustainable, employing environmental-friendly materials and processes, while retaining their skin-friendly characteristics. It is also disclosed hydrogel electrodes that were tested for ECG signal acquisition and outperformed the commercial electrodes. The hydrogel-based electrodes deliver high-quality ECG signals, boasting a superior signal-to-noise ratio (SNR) and remarkable resilience against interference and motion artifacts, compared to their commercial AgCl counterparts.

The invention relates to the technical field of packaging of power electronic devices, in particular to a three-dimensional packaged double-sided heat dissipation power module. The structure comprises an upper active metal brazing base material substrate and a lower active metal brazing base material substrate, a plurality of silicon carbide MOSFET chips, conductive strips and an inserter used for fixing the chips are arranged between the upper active metal brazing base material substrate and the lower active metal brazing base material substrate, the upper half-bridge chip is annularly arranged around a direct-current positive terminal, the lower half-bridge chip is annularly arranged around a direct-current negative terminal, and heat dissipation channels are formed in the upper surface and the lower surface of each chip. The impedance of branches is controlled to be equal, the current of each branch chip is balanced, the distance and layout of the chips are optimized, the overall loop area is reduced, the parasitic stray inductance of the module is reduced, in addition, the chips and the substrate are connected in a crimping mode, the chips and the copper columns are in contact through pressure to achieve electric heat conduction, the crimping materials are graphene sheets and molybdenum sheets, and the cost is low. Good contact between the chip and the copper columns is ensured, and contact resistance and thermal resistance are reduced. According to the invention, the effects of improving the heat dissipation efficiency, reducing parasitic stray inductance, balancing the current distribution of the parallel chips, and enhancing the module reliability and the conversion efficiency are achieved.

An integrated carbon honeycomb structure material and its preparation method are disclosed, belonging to the field of carbon materials technology. Based on a co-sacrificial template low-temperature pyrolysis strategy, the target material can be obtained through three main steps: preparation of a metal salt-colloidal microsphere template precursor, precursor pressing and molding, and subsequent calcination and carbonization. This technology has the characteristics and advantages of simple preparation process, regular and controllable macroscopic structure of the sample (such as shape, area, and thickness), rich and tunable chemical composition, and three-dimensional interconnection of graphene carbon matrix. It has great application potential in many fields such as electrochemical energy storage, catalysis, gas separation, adsorption, and electromagnetic shielding.

A pickleball ball is provided for increasing durability, improving performance, and / or reducing the loudness and / or frequency of sound generated when said ball strikes a paddle. The ball being a hollow ball comprised of a spherical shell defining a hollow cavity. The ball is made of a graphene-infused polymer material and the shell defines a plurality of holes distributed around the surface of the ball.

The invention belongs to the technical field of composite coatings, and particularly relates to a corrosion-resistant and ultraviolet-resistant protective coating for wind power generation equipment and a preparation method thereof.The corrosion-resistant and ultraviolet-resistant protective coating for the wind power generation equipment is prepared from, by mass, 40-60 parts of gradient fluorosilicone modified polyurethane resin, 5-12 parts of core-shell type ZnO-coated MOFs composite particles, 1-3 parts of a curing agent, 1-3 parts of a curing agent and 1-3 parts of a curing agent. According to the invention, the problems of poor ultraviolet resistance, poor weather resistance, poor corrosion resistance, poor corrosion resistance, poor corrosion resistance, poor corrosion resistance, poor corrosion resistance and the like in the existing coating and the preparation process thereof are well solved; the shielding layer is single and incapable and has a poor self-repairing effect; and the coating toughness of an epoxy resin system is insufficient and cannot adapt to fatigue deformation of equipment under a vibration working condition.

The invention relates to the technical field of cross-linked polyethylene cables, in particular to a mining cross-linked polyethylene insulated armored self-repairing cable and a manufacturing method thereof.The mining cross-linked polyethylene insulated armored self-repairing cable comprises a center conductor unit, a cross-linked polyethylene insulating layer, a shielding layer and an armored layer sequentially wrap the outer side of the center conductor unit from inside to outside, and an outer sheath layer is extruded on the outer side of the armored layer; the shielding layer comprises a semi-conductive shielding layer wrapping the outer side of the cross-linked polyethylene insulating layer, and the outer side of the semi-conductive shielding layer is wrapped with a copper strip shielding layer. By arranging the composite conductor structure in the central conductor unit and cooperating with the graphene heat dissipation filaments and the paraffin heat absorption and heat dissipation layer, the heat dissipation performance of the cable is improved, the temperature of the cable during operation is effectively reduced, faults caused by overheating are reduced, and the service life of the cable is prolonged; the armor layer and the copper strip shielding layer realize multipoint equipotential grounding through a sectional conductive adhesive tape, electromagnetic interference can be effectively shielded, and fault current diffusion is limited.

The invention relates to the technical field of gas detection, in particular to a multi-gas accurate detection method and system.The method comprises the following steps that gas to be detected flows through a miniature gas enrichment device prepared through an MEMS technology under driving of a miniature gas pump, and target gas is adsorbed and enriched through graphene and metal oxide composite sensitive materials on the surface of a spiral gas inlet flow channel in the miniature gas enrichment device; the desorption concentrated gas is heated to the multi-gas composite detector, and the sensor array reacts with the gas to generate an electric signal; the data acquisition unit performs noise reduction, amplification and analog-to-digital conversion preprocessing on the electric signal; the data processing unit extracts characteristic vectors such as a response curve peak value and a rising slope; inputting the feature vector into a pre-trained machine learning classification-regression combined model, and outputting a gas type identifier and an initial concentration; error compensation is carried out in combination with environment temperature and humidity and a cross sensitivity interference mode library, and finally accurate information of at least nine gases is output. The device has the advantages of high sensitivity, strong anti-interference performance and miniaturization.

The invention belongs to the technical field of crystal processing, and relates to a method for obtaining a single crystal diamond (111) surface wafer by using double-pulse-width laser. Femtosecond laser and picosecond laser are adopted for machining and stripping the blocky single crystal diamond to obtain a first crystal face (111), then femtosecond laser and picosecond laser are continuously adopted for machining and stripping the remaining blocky single crystal diamond, and the blocky single crystal diamond is obtained; the process for obtaining the crystal face (111) comprises the following steps of: scanning femtosecond laser on the crystal face (111) to process a plurality of graphitization modification lines which are full of the crystal face (111) and are parallel to each other, wherein the graphitization modification lines are parallel to the crystal orientation of a diagonal line [110] of the crystal face (001); carrying out scanning processing along the graphitization modification line by utilizing picosecond laser, so as to form a leap crack on the basis of the graphitization modification line of the crystal face (111); and then stripping is carried out. By means of the method, the wafer with the complete (111) face can be obtained through cutting in the ultra-thick (001) CVD monocrystal diamond.

The invention discloses a high-entropy alloy bonding phase SiC hard composite material and a preparation method thereof, the SiC hard alloy composite material is a double-phase composite material and comprises SiC and high-entropy alloy, and the high-entropy alloy is AlMnCuiFeTi and AlZnCuFeTi. The proportion of the raw materials is 5 wt.%-20 wt.%. And the size of the SiC particles is 200 [mu] m. During preparation, firstly, the high-entropy alloy is prepared through mechanical alloying; after uniform mixing, a graphite mold is filled with the mixture for prepressing, the prepressing pressure is 10-50 MPa, and prepressing is conducted for 10-30 s; and then hot pressed sintering is carried out, the sintering pressure is 20-50 MPa, the sintering temperature is 1400-2000 DEG C, heat preservation is carried out for 10-90 min, and the high-entropy alloy bonding phase SiC hard alloy composite material is prepared. The liquid phase generated in the high-entropy alloy sintering process is used for reducing the sintering temperature, the organization structure is improved, and the hardness and toughness of the tungsten carbide hard alloy are improved.

The invention belongs to the technical field of flexible sensors, and relates to a flexible temperature and pressure dual-mode sensor and array equipment. The temperature and pressure dual-mode sensor comprises a first flexible substrate, a force-sensitive conductive layer, an interdigital electrode layer, a second flexible substrate, a counter electrode layer and a temperature-sensitive layer which are sequentially stacked; the force-sensitive conductive layer comprises a microstructure layer stacked on the first flexible substrate and a conductive layer stacked on the microstructure layer; wherein the material of the microstructure layer comprises flexible resin and expanded microsphere powder, the interior of the microstructure layer is provided with a microsphere micropore structure formed by expansion of expanded microspheres, and the surface of the microstructure layer is provided with a plurality of protrusions and recesses; the temperature-sensitive layer is connected between the two counter electrodes of the counter electrode layer, and the temperature-sensitive layer is made of graphene.

The invention relates to the field of intelligent temperature control of industrial kilns, and discloses a graphitization furnace temperature uniformity optimization processing system which comprises a temperature monitoring module, a dynamic matrix control module, a material-control coupling module, a lattice feedback module and a multi-objective optimization module. The method comprises the following steps: constructing an equivalent temperature field through multi-source temperature data fusion; predicting a graphitization trend and generating a dynamic matrix control instruction in combination with a multi-physical field model; dynamically adjusting a thermal conductivity matching temperature gradient of the guard plate; online correcting a material constant based on lattice feedback; closed-loop control is formed, and the process stability and energy efficiency of the graphitization furnace are improved. Through multi-source fusion monitoring, multi-physical field coupling modeling, dynamic thermal conductivity regulation and control, lattice feedback online correction and reinforcement learning multi-objective optimization, temperature uniformity control and energy efficiency improvement of the graphitization furnace are realized, and material performance and process economy are guaranteed.

The invention discloses a preparation method of a B1-grade flame-retardant fire-resistant control cable, belongs to the technical field of flame-retardant fire-resistant cables, and aims to solve the technical problem that the mechanical strength and the fire-resistant and flame-retardant performance of an inorganic flame-retardant modified fire-resistant fire-resistant control cable in the prior art need to be further improved. The method comprises the following steps that a plurality of cable cores are arranged in parallel, gaps among the cable cores are filled with filling ropes to form filling layers, the cable cores filled with the filling layers are wrapped together through a wrapping tape, and a wrapping layer is formed outside the cable cores. According to the invention, maleic anhydride modified polyethylene is used as a phase solvent, and polyethylene is cross-linked and enhanced by modified graphite and modified polysiloxane, so that not only is the mechanical strength of the cable material effectively improved, but also the fire resistance and flame retardance of the cable material are improved.

The invention discloses a modified graphite felt electrode for an all-vanadium redox flow battery and a preparation method of the modified graphite felt electrode, and belongs to the technical field of redox flow battery electrode materials. The preparation method comprises the following steps: graphite felt electrochemical oxidation etching treatment; self-assembling a conductive layer on the oxidized and etched graphite felt to obtain the graphite felt attached with the conductive layer; and loading a metal and nitrogen-doped carbon (M and NC) nano catalyst layer on the graphite felt attached with the conductive layer to obtain the modified graphite felt electrode. Various properties of the graphite felt are comprehensively improved through matrix treatment, structure change and load catalysis, mild electrochemical oxidation etching is adopted, a carbon fiber structure is protected, a self-assembled net-shaped conductive layer forms a stable conductive channel, the specific surface area is remarkably increased, a nitrogen-doped carbon shell is adopted to wrap metal nanodots to form an M-NC catalytic layer, and the specific surface area is remarkably increased. The catalyst layer is not easy to dissolve out, the capacity fading rate is obviously improved, the loading capacity of the catalyst layer on the reticular structure conducting layer with a larger specific surface area is larger, and meanwhile, the process is simple and low in cost.

The invention discloses a battery monomer, a battery device and electric equipment, and belongs to the technical field of batteries. The battery monomer comprises a positive pole piece, a negative pole piece and a packaging bag, the positive pole piece comprises a positive current collector, a positive film layer and an insulating layer, the positive current collector comprises a positive main body part and a positive tab, the positive main body part comprises a coating area and a transition area, the transition area is located at at least one end of the coating area in the first direction, the positive film layer is arranged on at least one side surface of the coating area, and the insulating layer comprises a first part; the first part is arranged on at least one side surface of the transition area; the negative pole piece comprises a negative pole film layer, the edge of the negative pole film layer exceeds the edge, close to the positive pole lug, of the first part in the first direction, a chamfer structure is arranged at the joint of the first edge and the second edge of the negative pole piece, the negative pole film layer comprises graphite, and the volume average particle size Dv50 of the graphite is 8-20 microns; and the reliability and the cycle performance of the battery monomer can be improved.

The invention discloses a dry-type transformer. The dry-type transformer comprises a transformer body, a housing, a bottom plate and a fan, wherein the transformer body is formed by a plurality of groups of encapsulated windings in an array mode, a supporting rod is arranged at the bottom of the transformer body and allow the encapsulated windings in each group to connect with each other, the supporting rod is arranged in a crossed mode, and first threaded holes penetrate the supporting rod; the transformer body is integrally arranged in the cavity of the housing, and the bottom of the transformer body is fixedly positioned with the bottom plate, and meanwhile, the transformer body is arranged in the housing through the fan, the whole device achieves dispelling the heat in the transformerbody, and the graphite material of housing side is protruding simultaneously, and the heat from the housing is diffused quickly, and the protrusion of the array distribution can reduce the air great dust entering the inner wall of the housing through air vents.

The invention relates to the technical field of concrete preparation, in particular to high-performance self-compacting concrete and a preparation method thereof, solves the defects in the prior art, and comprises the following components: cement, fly ash, slag powder, graphene oxide, nano-silica aerogel, a water reducer and an air entraining agent. Through silanization modification and magnetic field induction, the problem of interface incompatibility of GO and SA is solved. Graded mass transfer paths are formed between nano layers of GO and mesopores and macropores of SA. And the CaCO3 seed crystal in the SA hole directionally guides the oriented growth of the C-S-H gel, so that the early strength development rate is increased.

In one aspect, a highly scalable diffusion-couple apparatus includes a transfer chamber configured to load a wafer into a process chamber. The process chamber is configured to receive the wafer substrate from the transfer chamber. The process chamber comprises a chamber for growth of a diffusion material on the wafer. A heatable bottom disk includes a first heating mechanism. The heatable bottom disk is fixed and heatable to a specified temperature. The wafer is placed on the heatable bottom disk. A heatable top disk comprising a second heating mechanism. The heatable top disk is configured to move up and down along an x axis and an x prime axis to apply a mechanical pressure to the wafer on the heatable bottom disk. While the heatable top disk applies the mechanical pressure, a chamber pressure is maintained at a specified low value. The first heating mechanism and the second heating mechanism can be independently tuned to any value in the working range.

Provided are a lithium manganese iron phosphate material and a preparation method therefor, a positive electrode sheet, and a lithium ion battery. The lithium manganese iron phosphate material comprises a core and a coating layer that coats the surface of the core. The chemical formula of the material of the core is LiaMnbFecMdPO4, wherein M comprises at least one element among magnesium, calcium, strontium, cobalt, titanium, zirconium, molybdenum, vanadium, niobium, nickel, scandium, chromium, copper, zinc, beryllium, lanthanum and aluminum. The coating layer is formed by sintering a carbon source, and the carbon coating layer comprises graphitized carbon.

The technical scheme of the invention relates to the technical field of data processing, in particular to a method for improving the rapid cooling efficiency of a high-temperature graphite furnace, and the method comprises the steps: carrying out the time axis normalization processing based on a cubic spline interpolation algorithm, combining an adaptive Kalman filter, fusing multi-source data, and generating a time-synchronized three-dimensional temperature field reconstruction matrix; the problem of temperature field reconstruction lag caused by insufficient time sequence alignment precision of multi-modal sensing data is solved. And the reinforcement learning network dynamically optimizes the control parameter weight through the residual feature map, preferentially corrects the deviation of the rotating speed of the induced draft fan and the gas injection angle in a high-error region, and feeds back the deviation to the thermodynamic simulation model for online iterative updating of the specific heat capacity parameters of the material, so that model prediction and dynamic calibration of the actually measured thermal field are realized. Through multi-source data alignment, closed-loop feedback and cooperative control architecture, the timeliness and execution precision of cooling path planning are remarkably improved, and the cooling efficiency and equipment reliability of the high-temperature graphite furnace are optimized.

The invention discloses a rolling and annealing treatment process for a copper-steel composite strip, and relates to the technical field of material rolling, the process comprises the following steps: selecting a high-purity copper plate and a stainless steel plate, and depositing a nano nickel / graphene composite transition layer through a magnetron sputtering technology; the stainless steel layer is promoted to deform through front-section low-speed high-pressure rolling, and the copper layer interface bonding force is improved through rear-section high-speed low-pressure rolling; performing short-time local annealing by using a high-frequency induction coil; honeycomb-shaped micro-pits are formed in the stainless steel surface through the laser micro-texture technology, and the interface bonding force is improved in combination with the nano-nickel / graphene layer. Copper layer hardening is eliminated through low-temperature annealing, stainless steel recrystallization is promoted through medium-temperature annealing, and a nanometer precipitated phase is fixed through rapid water cooling; the heating rate is controlled, and nitrogen-hydrogen mixed gas is used for preventing oxidation; the rolling process and the annealing process are seamlessly connected, and the temperature, the stress and the atmosphere are detected in real time through an online monitoring system. The mechanical property, the corrosion resistance and the machining stability of the copper-steel composite strip are remarkably improved.

The invention relates to the technical field of electrical property detection, and discloses a graphene film surface property detection device, which comprises a data acquisition module used for acquiring electrical property data of the surface of a graphene film through a multi-point array electrode probe; the vector grid modeling module is used for constructing a vector grid model for representing the surface performance of the graphene film according to the electrical characteristic data; the iterative inversion calculation module is used for performing iterative inversion calculation on the vector grid model to determine the surface performance distribution of the graphene film; the parallel optimization fusion module is used for performing parallel processing and optimization fusion on the multi-scale performance data through a distributed computing framework; the three-dimensional visualization module is used for generating a three-dimensional visualization model of the surface performance of the graphene film according to the optimized and fused performance data; the problems of insufficient precision and low efficiency of a traditional detection method in graphene film performance detection are solved.

The invention relates to the field of building materials, and discloses a multifunctional foamed ceramic sound insulation and heat preservation material for buildings. Comprising the following raw materials in parts by weight: 42 to 48 parts of pottery clay tailings, 14 to 16 parts of fly ash, 10.5 to 12 parts of crushed stone materials, 2.8 to 3.2 parts of a silicon carbide foaming agent, 0.7 to 0.8 part of a borax fluxing agent, 7 to 8 parts of paraffin / silicon dioxide phase change microcapsules, 0.5 to 1.0 part of graphene, 2.0 to 2.5 parts of nano iron powder, 0.05 to 0.5 part of nano silver, 1.0 to 1.5 parts of photocatalytic titanium dioxide and 0.3 to 0.4 part of a fluorosilane coupling agent. A stable matrix structure is constructed through the argil tailings, the fly ash and the crushed stone materials, the silicon carbide foaming agent and the borax fluxing agent reduce the heat conductivity coefficient, the sound insulation performance is improved, the material is endowed with the antibacterial ability through nano-silver and photocatalytic titanium dioxide, indoor sanitation is guaranteed, and a super-hydrophobic layer is constructed through the fluorosilane coupling agent.

The invention discloses a graphite negative electrode powder laser particle size detection device, relates to the field of particle size detection, and solves the problem that an existing particle size detection device is difficult to continuously detect multiple batches of graphite samples, the graphite negative electrode powder laser particle size detection device comprises a device shell and a control top plate arranged above the device shell, and a driving rod and a laser detection head are mounted at the bottom of the control top plate; stirring fan blades are installed at the bottom of the driving rod, a rotating disc is rotationally installed at the top of the device shell, and two symmetrically-distributed detection cylinders and two symmetrically-distributed cleaning cylinders are arranged at the top of the rotating disc; the lifting mechanism is used for lifting the driving rod upwards, and the lifting mechanism is mounted on the inner side of the device shell; through the lifting mechanism, in the rotating process of the rotating disc, the stirring fan blades and the driving rod are lifted upwards and reset downwards, so that the stirring fan blades and the driving rod enter the detection barrel and the cleaning barrel conveniently, particle size detection of a graphite sample and cleaning of the stirring fan blades are realized, and the effect of continuous detection is achieved.

The invention belongs to the technical field of silicon carbide single crystal materials, and particularly relates to a growth device of large-size silicon carbide single crystals and a preparation method of the silicon carbide single crystals, porous graphite cylinders are arranged in a powder area of the growth device of the large-size silicon carbide single crystals, and the porous graphite cylinders are distributed along the edge of the powder area to the center in a stepped mode. The height is gradually increased from the edge to the center; a plurality of layers of stacked graphite pore plates are arranged at the top of the powder area, the upper end parts of the porous graphite cylinders are flush with the upper surfaces of the corresponding layers of graphite pore plates, and the porous graphite cylinders penetrate through the graphite pore plates, so that a continuous gas phase transmission channel from the powder area to the crystal growth area is formed. According to the invention, the plurality of porous graphite cylinders are arranged in the silicon carbide raw material area in a stepped manner, so that the temperature field distribution of the raw material area is stabilized, the gas phase layout is optimized, impurities in gas phase components are filtered, and the defects of microtubes, inclusions, dislocation and the like in crystals are improved.

The invention relates to a preparation method of a high-purity manganese target material, which belongs to the technical field of metallurgy, and comprises the following steps: firstly, drying manganese powder, then pouring the manganese powder into a graphite mold, and putting the graphite mold into a Joule hot sintering furnace for sintering, during sintering, a strategy of two-stage prepressing and four-stage gradient pressing of prepressing forming, low-pressure degassing, medium-pressure densification and high-pressure sintering is implemented, and low-temperature sintering is realized; through two-stage cooling after sintering, stress and cracking in the cooling process are avoided; by accurately controlling the temperature and time of each stage, the defects that high heating temperature and long heat preservation time are needed are overcome. The production process is integrally simplified, the internal stress is controlled to be effectively and gradually released at different temperatures, the porosity is reduced, and sintering cracking is avoided; by optimizing the sintering atmosphere of each stage, the influence of impurities such as oxygen in the air on the purity of the sintered manganese target material is avoided, and the purpose of preparing the high-purity manganese target material with low energy consumption, high efficiency and high quality is achieved.