150results about How to "Improve doping effect" patented technology

The invention relates to a preparation technology for graphene transparent conductive films, in particular to a large-scale preparation method for stably-doped large-area graphene transparent conductive films. According to the method, the doping effect and stability of the graphene transparent conductive films are improved through a sandwich structure, and a doping agent is in direct contact with the intrinsic surface of graphene and positioned between the graphene and a transparent substrate. The method comprises the following steps: firstly, forming the doping agent on the surface of the graphene or the transparent substrate on an initial substrate; secondly, combining the graphene, the doping agent and the transparent substrate; finally, separating the graphene from the initial substrate so as to prepare the stably-doped large-area graphene transparent conductive films. The graphene serves as an outer-layer protection film of the doping agent, so that the doping stability can be improved; the intrinsic surface of the graphene is in direct contact with the doping agent, so that the pollution of an interface between the graphene and the doping agent by impurities can be avoided, the doping effect of the doping agent can be improved, and the conductivity of the film can be enhanced; the transferring and doping processes of the graphene are combined, so that the large-scale preparation can be easily realized.

The invention provides a sodium ion doped high-nickel ternary lithium battery positive electrode material and a preparation method. The preparation method comprises the following steps: preparing an 811-type NCM (Nickel Cobalt Manganese) ternary positive electrode precursor through a co-precipitation method; after drying and grinding the precursor, mixing the ground precursor with powdery sodium peroxide and lithium oxide; pre-firing and sintering under an oxygen-rich environment to prepare the sodium ion doped high-nickel ternary lithium battery positive electrode material. According to the method provided by the invention, the defects that Ni<2+> is difficulty effectively controlled to be released from and embedded into a lamellar structure in a sintering process so that a structure is changed in a desorption process and the capacity of lithium ions is reduced are effectively overcome; sodium peroxide is changed into a molten state in a pre-firing process and permeates into the precursor, so that the Ni<2+> is oxidized into Ni<3+>; meanwhile, a lithium layer is occupied and an interlayer structure is expanded; the Ni<2+> is prevented from being migrated into the lithium layer ina sintering process; technical effects that nickel and lithium mixed arrangement of the high-nickel NCM positive electrode material is reduced, the migration rate of lithium ions is improved and the circulating performance of the battery is improved are realized.

The invention provides an epitaxial growth method of a purple-light LED. The suitable wavelength range of the method is 365-420 nm, the growth difficulty of the purple-light LED can be greatly lowered, meanwhile, the radiation power of the purple-light LED can be increased and the reliability of purple-light LED devices is effectively improved. In the epitaxial growth method, an n-type AlGaN / GaN super lattice structure is adopted, potential-barrier-layer AlGaN and potential-well-layer GaN are doped alternately periodically, and therefore concentration of n-type carriers can be concentrated; the concentration of different layers change periodically, and periodic conductance changes enable currents to be diffused better; meanwhile, the conductance changing area is widened, so that the transmitting effect of an electric leakage channel with linear defects is weakened, forward voltage can be lowered, and ESD can be improved.

The invention provides a preparation method for a multilayered graphene film, which includes the following steps: (S1) a polymer supporting layer is formed on a graphene film growing on the surface of a metal layer; (S2) the metal layer is dissolved, and the polymer supporting layer / graphene film is doped; (S3) another graphene film growing on the surface of a metal layer is covered by the polymer supporting layer / graphene film; (S4) metal layer dissolution and doping are carried out again; (S5) a target substrate is covered by the polymer supporting layer / graphene film, and the polymer supporting layer is removed. By flexibly controlling the frequency of repeating the steps S3 and S4, the graphene film with a needed layer number which is located on the target substrate can be obtained. By repetitively utilizing the polymer supporting layer formed in one step in the process of transfer, the preparation method prevents polymer from remaining among the layers of graphene; moreover, since chemical doping is carried out in the layer-by-layer transfer process, doped ions are located among the layers of graphene, and cannot easily separate from the graphene film, and thereby the doping effect is prolonged.

The invention belongs to the technical field of media content safety monitoring, and discloses an Internet media content safety monitoring system and method based on artificial intelligence. The Internet media content safety monitoring system comprises an infrastructure module, a data processing module, a media data center, a content analysis module, an application service module, a man-machine interaction module, and an operation and maintenance management module. According to the invention, text, sound, images and video contents in the Internet media can be monitored, and bad information canbe found and tracked; meanwhile, specific media content can be mined and analyzed according to the requirements of the user,and a data analysis early warning report of related content is provided for the user, and the timeliness, effectiveness and scientificity of management decision making are improved; and a scientific and technological supporting means is provided for supervision of related industries. The Internet media content safety monitoring system is mainly deployed on a parallel computing server, and a single server processes about 180000 images every day, and the video processingduration every day reaches 800 hours, and meanwhile, the platform can perform distributed computing of multiple servers.

The invention relates to a method for preparing graphene powder through rapid heat treatment in an air atmosphere. The method comprises the steps that a precursor of graphene is placed in an unsealed covered crucible, and then subjected to heat treatment in the air atmosphere, and the graphene powder is obtained; alternatively, the precursor of graphene is uniformly mixed with a nitrogen-containing compound, then placed in the unsealed covered crucible, and subjected to the heat treatment; and nitrogen doped graphene powder is prepared. The method requires no protection from inert gas or reducing gas, so that a requirement on equipment is lowered; a heat treatment temperature of graphene is reduced to 250-850 DEG C; a range of the heat treatment temperature of graphene is expanded greatly; in addition, energy consumption is reduced; nitrogen controllable doping of graphene is realized; and the controllable doping facilitates an application of the graphene powder.

The invention relates to a nitrogen and phosphorus co-doped carbon material as well as a preparation method and application thereof, aiming at solving the technical problems that the existing materialis complicated in preparation method and poor in repeatability. The nitrogen and phosphorus co-doped carbon material is prepared by taking polydopamine or bacterial cellulose as a carbon source and using a hexachlorophosphazene monomer as a nitrogen and phosphorus co-doped source. The invention also provides the preparation method and application of the nitrogen and phosphorus co-doped carbon material. The nitrogen and phosphorus co-doped carbon material can be applied to the field of preparation of battery materials.

The invention discloses a method for preparing a manganese phosphate iron phosphate-carbon composite material and the manganese phosphate iron phosphate-carbon composite material. The method comprisesthe following steps of (1) respectively preparing soluble manganese phosphate-containing solution A, soluble organic ferric salt solution B, soluble organic manganese salt solution C and soluble organic lithium salt solution D; (2) mixing the solution A, B, C and D according to a predetermined element molar ration so as to obtain precursor solution; (3) drying and pelleting the precursor solutionobtained in the step (2) to obtain manganese phosphate iron phosphate precursor powder; (4) sintering the precursor powder obtained in the step (3) under a protection atmosphere to obtain a sinteredmaterial; and (5) carrying out smashing thinning and vacuum packaging on the material obtained in the step (4) to obtain the manganese phosphate iron phosphate-carbon composite material. The method issimple and easy to do and suitable for large-scale industrial production. The obtained material can be used as an active material for the anodes of the lithium ion batteries, and is low in resistivity and excellent in electrochemical performance.

The invention discloses bulk-phase doped manganous-manganic oxide. The bulk-phase doped manganous-manganic oxide is doped with at least one element of yttrium, ytterbium, lanthanum and niobium, wherein the doping amount of the doping element is 0.1%-1.0%, the particle size D50 of manganous-manganic oxide is 3-20 microns, and the tap density is greater than or equal to 1.5 g / cm<3>. The preparationmethod comprises the steps: under a stirring condition, continuously adding a divalent manganese salt and a soluble doped salt solution and ammonia water into a reactor to carry out a coprecipitationreaction, and adding an oxidant to carry out oxidation treatment, so as to obtain the bulk-phase doped manganous-manganic oxide. The manganous-manganic oxide or the manganous-manganic oxide prepared by the preparation method is used as a precursor and mixed with a lithium source, and the mixture is roasted to obtain a lithium ion battery positive electrode material lithium manganate. In the manganous-manganic oxide disclosed by the invention, the doping elements are in uniform bulk phase distribution in microcosmic particles, so that the gram volume of lithium manganate can be improved, the compaction density of the lithium manganate can be improved, and the high-temperature performance and the cycle performance of a lithium manganate product can be remarkably improved.

The invention discloses a method for enhancing heterogeneous molecule-doped molybdenum disulfide based on electronic dynamic regulation, and belongs to the field of micro-nano manufacturing. The method comprises the following steps of step 1, enabling a femtosecond laser pulse sequence to focus onto the single or multiple molybdenum disulfide layers at the surface of a substrate, controlling the processing parameters and processing location of the femtosecond laser pulse sequence, inducing the defect mode with controllable degree and location at the surface of the molybdenum disulfide meetingthe preset use requirements, and enabling the molybdenum disulfide with defect mode / active point to effectively adsorb oxygen in air under the air environment, so as to obtain the controllable oxygenmolecule P-doped single or multiple molybdenum disulfide layers; step 2, dripping an N-doped organic matter / inorganic matter / biological molecule solution onto the single molybdenum disulfide layer with defect mode / active point, and waiting for natural airing, so as to obtain the organic matter / inorganic matter / biological molecule N-doped single molybdenum disulfide layer. The method has the advantages that the degree and location of the defect mode are controllable, the operation is simple and flexible, and the like.

The invention discloses a preparation method of a phosphorus-doped lithium-rich manganese-based cathode material for a lithium ion battery, in particular comprising the steps of preparing precipitantsolution, preparing metal salt solution, preparing phosphorus-doped nickel-cobalt-manganese carbonate precursor, and preparing phosphorus-doped lithium-rich manganesebased cathode material; The precursor of phosphorus-doped Ni-Co-Mn compound can be obtained by dissolving the pyrophosphate compound as phosphorus source in precipitant solution and coprecipitating, and the phosphorus-doped lithium-rich manganesebased cathode material can be obtained by sintering at high temperature. The preparation method disclosed by the invention is simple, and the prepared cathode material is not only doped with phosphorus on the surface, but also evenly doped with phosphorus inside the material, so that the performance of the material is stable, the service life is long, and the capacity, the first effect, the ratio and the cycle stability of the material are remarkably improved.

The present invention provides a method for producing the buffer layer of a conductor coated with high temperature superconducting coating by means of macromolecule assisted nitrate deposition, a. producing a waterless weigh rare earth nitrate or zirconium nitrate and cerous cerium nitrate at an ionic ratio of rare-earth or zirconium: cerium as x:1-x (0.01<=x<=0.5), and dissolve the elements in N,N-dimethyl formamide to form a waterless solution; b. preparing colloid: add polyacrylic acid or polymethacrylic acid to the waterless solution prepared in step a; c. coating the colloid and drying: coat the colloid prepared in step b on a substrate and the dry the substrate. d. sintering: load the dry substrate into a sintering oven, heat up to 850-1150 DEG C at 5-100 DEG C / min speed, hold for 0.25-2h, and then drop the oven temperature to room temperature. The method is characterized in simple process, easy operation control, low cost, and free of environment pollution; the single-layer cerium oxide buffer layer obtained can be in thickness up to 150-200nm.

The invention discloses a preparation method of a lithium-ion-battery anode material with bulk-phase-doped metal elements, relates to the field of secondary batteries, and aims to solve the problem that the doping process is complex, the varieties of doped elements are few, the electrochemical performance is not ideal due to the poor doping effect in the prior art. The preparation method includes the steps of firstly, preparing the precursor of the lithium-ion-battery anode material; secondly, preparing a high-concentration organic metal salt derivative solution; thirdly, using a vacuum impregnation method to prepare the lithium-ion-battery anode material precursor doped by organic metal salt derivatives; fourthly, blending lithium into the lithium-ion-battery anode material precursor doped by the organic metal salt derivatives, and sintering to obtain the lithium-ion-battery anode material with the bulk-phase-doped metal elements. The lithium-ion-battery anode material is applicable to the field of batteries.

The invention discloses a method for preparing a gradient thermal barrier coating and the method is used for preparing the gradient thermal barrier coating on the surface of a metal. 40-80mu m ceramic particles are bound on the surface of a metal substrate by virtue of a thermal spraying or laser cladding method to prepare the nano-ceramic particle-reinforced thermal barrier coating, wherein the nano-ceramic particles are uniformly dispersed and have a particle size of 100-500nm, the 40-80mu m ceramic particles are obtained by agglomerating initial nanoparticles and comprise Al2O3 particles, ZrO2 particles and rare earth zirconate particles and the component of the rare earth zirconate particles is A2Zr2O7, wherein A is one or more of Ln, La, Gd and Nd. The gradient thermal barrier coating prepared by the method is good in thermal-insulation effect and is firmly bound with the metal substrate and the problems that the existing gradient thermal barrier coating is difficult to be successfully applied and is easy to fall off to cause failure under thermal cycling conditions are solved.

The invention relates to a nitrogen-doped graphene nanobelt and a preparation method thereof. The preparation method comprises the following steps: preparing a carbon oxide nano wall slurry; and preparing the nitrogen-doped graphene nanobelt. In the nitrogen-doped graphene nanobelt preparation process, a technique of mixing the nitrogen source and carbon oxide nano wall by a liquid phase is utilized, so that the nitrogen-doped graphene nanobelt has the advantages of better doping effect and favorable uniformity; and the ionic liquid used as the solvent can effectively prevent the graphene nanobelt from reaggregation, so that the preparation process can be completed through simple separation and drying.

A preparation method of a magnesium diboride-doped superconducting material comprises the following steps: respectively weighing magnesium powder and boron powder based on a mol ratio of 1:0.7-2.5; weighing a dopant based on the ratio of the total mass of the magnesium powder and the boron powder to the mass of the dopant of 1:0.01-1, wherein, the dopant is one of sorbic acid or sorbate; evenly mixing the magnesium powder, the boron powder and the dopant powder to obtain mixed powder; and sintering the mixed powder under the protection of argon atmosphere at the sintering temperature of 600 DEG C-1200 DEG C, and keeping the temperature for 0.5-12 hours, thus obtaining the superconducting material. The method has the advantages of short preparation time, low reaction temperature, high efficiency and low cost, and is especially suitable for industrialized production. The magnesium diboride superconducting material obtained by the method has obviously increased critical current density especially very high critical current density in a high magnetic field, which is beneficial to the application of the superconducting material to the high magnetic field; and the superconducting material has strong practicability.

A method for producing the buffer layer of a conductor coated with high temperature superconducting coating by means of macromolecule assisted deposition, which comprises: a. preparing waterless: weigh rare-earth acetate, or rare-earth propoxide, or rare-earth acetylacetonate, or zirconium propoxide, or zirconium n-butoxide and cerium acetylacetonate at an ionic ratio of rare-earth or zirconium: cerium as x:1-x (0.01<=x<=0.5), dissolve the compound in an organic solvent to form a waterless; b. preparing colloid: add polyvinyl butyral, or polyethylene glycol, or polyvinyl pyrrolidone, or polyvinyl alcohol, or polyoxyethylene to the waterless solution to form colloid; c. coating the colloid and drying: coat the colloid on a substrate and then dry the substrate; d. sintering: load the substrate into a sintering oven, heat up to 850-1150 DEG C at 5-100DEG C / min, hold for 0.25-2h, and drop the temperature at 1-2 DEG C / min to room temperature. The method is characterized in simple process, easy operation control, low cost, and free of environment pollution; the single-layer cerium oxide buffer layer obtained can be in critical thickness of 150-200nm.

The invention discloses a method for preparing a carbon-based super-capacitor electrode material from wood powder. The method includes mixing wood powder with alkali, nitrogen source and water according to the weigh ratio of 1 to (1-6) to (2-12) to (5-30) while stirring for 5 to 20 hours to obtain a mixture; freezing the mixture at the temperature of -20 to -60 DEG C for 12 to 24 hours and then drying the same at the temperature of -60 to -100 DEG C for 1 to 6 days to obtain another mixture; treating the mixture while raising the temperature from room temperature to the temperature of 700-1000DEG C by the speed of 1-5 DEG C / min under protection of nitrogen gas for 1 to 4 days, then cooling to the room temperature to obtain a black product; mixing the black product with deionized water according to the weigh ratio of 1 to 20-70 while stirring for 10 to 30 minutes, standing for 2 to 4 hours, filtering and washing the product until the product is neutral, and then drying the product for12 to 24 hours to obtain the finished product carbon powder. With treatment of activation and pre-doping, carbonization, activation and element doping are achieved synchronously by one high-temperature processing only, preparation is simplified and production cost is lowered.

The invention belongs to a production method for tungsten alloy for electrode use, including: preparation of rare earth nitrate solution, preparation of rare earth doped with blue tungsten, reducing, preparingunburnt earthenware, sintering and vertically melting. The method takes blue tungsten with large specific surface, developed surface cracks as raw materials, dissolves high purity rare earth nitrate in deionized water as additives; in the production process, slurry evaporation drying methods adopts low temperature agitation evaporation, then higher temperature evaporation for drying to avoid segregation caused by rapid doping precipitation by the direct use of high-temperature drying; Blue-doped tungsten and tungsten powder has loose particles with particle size consistent with mormal, good formability and good sintering properties and physical properties for follow-up processing. The method has the advantages of advanced technology, reliablity, short process, uniform distribution of rare earth and stable quality, good machining properties and functional performance and can be used for large-scale industrialized production, and other characteristics. The method overcomes frauds of the technical background doping effect and the quality of stability, moldability, downstream processing and poor functional performance ills.

The invention discloses a method for preparing a nano-doping metal organic framework with photocatalytic performance. The method comprises the following steps: a tetrabutyl titanate coated nano particle sol is prepared by polyvinylpyrrolidone and absolute ethyl alcohol, and ethyl silicate is adopted to perform doping reaction to obtain a silicon-doped nanometer titania sol; ferric chloride, terephthalic acid and acetic acid are added into absolute ethyl alcohol for sealed refluxing and standing crystallization reaction; filtering and washing are performed to obtain the metal organic framework; at last,absolute ethyl alcohol is added into the metal organic framework, and the sol is dripped for aeration circular reaction; and high-temperature treatment is performed to obtain the nano-doping metal organic framework. The prepared nano-doping metal organic framework has a favorable specific surface area, meanwhile, has favorable photocatalytic performance and also has a favorable degradation effect.

The invention relates to the field of concrete, and particularly discloses freeze-thaw resistant concrete and a preparation method thereof. The freeze-thaw resistant concrete is prepared from, by weight, 30-50 parts of coarse aggregate, 30-40 parts of fine aggregate, 10-15 parts of cement, 8-15 parts of water, 4-6 parts of mineral powder, 2-3 parts of coal ash, 0.1-0.5 part of additive, 6-8 parts of composite sol and 1-2 parts of freeze-thaw resistant modified fiber; wherein the freeze-thaw-resistant modified fibers comprise calcium sulfate whisker chopped fibers with the length of 1-2 mm. The calcium sulfate chopped whiskers and the composite sol are adopted as modified materials and are filled in the concrete, and in the process that the concrete is frozen and cracks, the phenomenon that concrete cracks are continuously expanded in a freeze-thaw environment and consequently the concrete cracks are broken is prevented through stress existing in entangled fibers; therefore, the loading mode of the composite fibers between the concrete is improved, and the freeze-thaw crack resistance of the freeze-thaw resistant concrete is further improved.

The invention belongs to the field of crystalline silicon solar cells, and relates to a heterojunction solar cell and a preparation method thereof. The method mainly solves the technical problems that in the prior art, due to the fact that the thermal stability of a P-type doping layer of a heterojunction solar cell is poor, B atoms are likely to diffuse and enter an amorphous silicon intrinsic layer and the optical forbidden band width of the P-type doping layer formed through doping of pure diborane gas is low, the defect state density of boron-doped amorphous silicon and the recombination current density of an emitting electrode are increased due to doping of high-concentration diborane gas, and the design of a P-type doping layer is imperfect. The scheme provides the heterojunction solar cell and the preparation method thereof. The method comprises the steps: designing P-type doped layer into a laminated structure which comprises a first P-type doped layer which is in contact with an intrinsic amorphous silicon layer and contains trimethyl boron gas deposition, and at least two layers of overall layered structures with gradually increased boron doping concentration deposited by trimethyl boron and diborane gas. The preparation steps are simple, the cost is low, and the obtained heterojunction solar cell is excellent in performance.

This invention relates to a kind of phospho-silicate Kelly steady persistence glass and preparation method. This invention selects ethyl silicate, dihydrogen phosphate ammonia and zinc oxide as main glass matrix, citric acid as sequester, and single incorporation of terbium ion. The glass molar composition is expressed as follow formulae: ( A - X) ZnO - bP2O5 - cSiO2 - xRO - d Tb4O7. The method of preparation is: dissolve ethyl orthosilicate in appropriate amount ethanol, dissolve dihydrogen phosphate ammonia and citric acid respectively in distilled water; dissolve zinc oxide and RO in nitric acid of 1:1, dissolve terbium oxide in form aqua fortis; then mix above liquid under stirring condition, whipping for one hours, the adjust PH about 0.5 to 3, keep on whipping for 1 hour to form collosol, then enter 50 to 90 deg water-bath for collosol / gelatin reaction, form gel, then enter 100deg baking over for drying; 1200 to 1500 deg constant temperature for 0.5h to 2 hours, annealing treatment 0.5 to 3 hours, gain colorless, transparent steady persistence glass; use UV254nm ultraviolet to stimulate, remove excitation light source, in the dark the vitreous kelly steady persistence hour can reach 10 hours upwards.

The invention discloses a process method for producing quartz tubes by using a solid state method. The process method comprises the following steps of: (1) selecting a rare-earth element; (2) uniformly mixing a plurality of kinds of solid rare earth nitration according to the quantity of quartz melting materials inside a continuous melting furnace; (3) mixing and stirring the uniformly mixed rare earth nitration by using a turbine stirring machine; (4) adding the rare earth nitration into the continuous melting furnace directly; (5) adding the rare earth nitration into the continuous melting furnace; (6) continuously rising the temperature of the rare earth nitration and the quartz material; (7) rising the temperature of the continuous melting furnace gradually; (8) keeping the temperature inside the furnace to be black red; (9) generating the black red quartz tube and wholly coloring and shaping; and (10) continuously producing the wholly colored black red quartz tube. The process method has the advantages of simple process and low cost.

The invention relates to a method for preparing a metal nickel nano-particle doped MgB2 superconducting material by a reduction method. Firstly, Ni(OH)2-B precursor powder is prepared, Ni(NO3)2.6H2O powder and B powder are fully mixed and stirred in distilled water, and a NaOH solution is used to titrate; and secondly, a precipitate is dried to remove water in a vacuum drying oven; the dried Ni(OH)2-B precursor powder is placed into a tubular furnace to be calcined under the protection of nitrogen or argon to ensure that Ni(OH)2 is decomposed to obtain NiO-B mixed powder; H2 is introduced after the temperature rise, and the flow makes NiO fully reduced to obtain the Ni-B mixed powder; and a mixed tablet of Mg power and Ni-B powder which meets the atomic ratio that Mg : B is equal to 1-1.5: 2 is weighed in a differential thermal analyzer (DTA), is sintered for 30 to 60 minutes at a temperature of between 650 and 850 DEG C, and then is cooled to room temperature. The average diameter of nickel particles prepared by the method is 5 nanometers, the nickel particles are evenly distributed inside a B matrix, and an obtained test sample has steady components, is difficult to form the agglomeration, and has apparent morphological feature. Compared with other metallic dopants, the material has the advantages of simple preparation method, low cost, apparent doping effect and so on.

The invention discloses a preparation method of a graphene composite Fe (Se, Te) superconducting material. The method comprises the steps: 1, grinding mixed powder; 2, putting the ground mixed powder into a mold, sealing, and pressing to obtain a Fe-Se-Te green body; 3, carrying out sintering treatment to obtain a Fe (Se, Te) superconducting material block; 4, performing high-energy ball milling treatment on the Fe (Se, Te) superconducting material block and graphene to obtain graphene mixed Fe (Se, Te) superconducting powder; and 5, carrying out spark plasma sintering to obtain the graphene composite Fe (Se, Te) superconducting material. According to the invention, graphene is adopted as a dopant to carry out doping compounding on Fe (Se, Te) superconducting material blocks, so that on the premise that the superconducting performance of the system is not reduced, the elastic modulus of the FeSe system is effectively reduced, the mechanical property difference between the superconducting material and the outer sheath is reduced, and the mechanical property and the superconducting performance of the superconducting wire strip are improved.

The invention provides an ultraviolet LED high-counter electrode. The ultraviolet LED high-counter electrode comprises an ohmic contact layer, a reflection metal layer, a diffusion barrier layer and aflip-chip bonding layer which are sequentially laminated on the surface of a p-type semiconductor layer, wherein the ohmic contact layer is mainly formed by metal oxide, the bandgap width of the metal oxide is greater than 3eV, the work function is greater than 6eV, and the sheet resistance of the formed film is less than 500ohm / square. The invention also provides an ultraviolet LED comprising the ultraviolet LED high-counter electrode. According to the invention, Ni in a traditional high-counter electrode Ni / Al is replaced by the metal oxide, the Ni layer is prevented from strongly absorbingultraviolet light, and the metal oxide belongs to a wide bandgap semiconductor material and is combined with the high-ultraviolet reflection metal layer, so that the ultraviolet light can be effectively reflected, and the photon extraction efficiency of the ultraviolet LED chip is improved; and the metal oxide is matched with the work function of the p-type semiconductor layer, so that better ohmic contact can be formed, and lower contact resistance can be obtained.

The invention relates to nitrogen-doped graphene nanoribbons and a preparation method thereof. The preparation method comprises the following steps: preparation of oxidized carbon nano wall slurry; and preparation of the nitrogen-doped graphene nanoribbons. The nitrogen-doped graphene nanoribbons belong to N-type doping, the electron concentration can be increased, and at the same time, the conductivity of the graphene nanoribbons can also be improved, so that the nitrogen-doped graphene nanoribbons have more advantages as a conductive additive in a switch device. Moreover, the yield of the nitrogen-doped graphene nanoribbons is high, the specific conductance of the nanoribbons is also improved, raw material can be self-prepared, and the production cost is reduced. Equipment required in the preparation process is common chemical equipment, so that the cost of the research and development equipment can be saved, and mass production is fitted.

An object of the present invention is to provide a non-aqueous electrolyte secondary battery which has a large charge / discharge capacity, has a small irreversible capacity, and is capable of effectively using an active material.This object can be achieved by a material for a non-aqueous electrolyte secondary battery anode; a specific surface area determined by a BET method being not greater than 30 m2 / g; an atomic ratio (H / C) of hydrogen atoms to carbon atoms determined by elemental analysis being not greater than 0.1; an average particle size being not greater than 50 μm; and a diffraction intensity ratio (R-value) determined by Equation (1) being not greater than 1.25: (wherein Imax is a maximum value of a 002 diffraction intensity of carbon measured at an angle of diffraction (2θ) within a range of from 20 to 25° as determined by powder X-ray diffraction measured using CuKα rays; Imin is a minimum value of a diffraction intensity measured at an angle of diffraction (2θ) within a range of from 15 to 20° as determined by powder X-ray diffraction; and 135 is a diffraction intensity at an angle of diffraction (2θ) of 35° as determined by powder X-ray diffraction).