70results about How to "Many defects" patented technology

The invention provides a preparation method for Portland cement with iron tailings. The Portland cement comprises at least the following raw materials in percentage by weight: 60-70% of calcium oxide, 12-20% of silicon oxide, 5-20% of the iron tailings and 3-6% of aluminium oxide. The preparation method comprises the following steps: weighing the raw materials according to the mass ratio, and mixing uniformly and fine grinding the weighed raw materials; calcining the fine grinded raw materials in a high-temperature furnace, and drawing out and quenching the calcined raw materials to obtain clinkers; adding the iron tailings to the clinkers, mixing uniformly mixtures of the iron tailings and the clinkers, and fine grinding the mixtures to obtain the Portland cement with the iron tailings, wherein the mass of the added iron tailings is 1-8% of the total mass of the clinkers. The method provided by the invention can effectively use the iron tailings as raw materials for production to prepare the Portland cement with excellent quality, so that the deficiencies in the prior art can be overcome, the use of the iron tailings can be maximized, and the purposes of saving resources, reducing the production cost, protecting environment and the like can be realized.

The invention discloses an adjustable table which is characterized in that four pull pipes are inserted into four upright table legs respectively; a transverse rod is fixed to the upper ends of the pull pipes of the two rear table legs, two hinged seats penetrate the transverse rod, and a base is fixed on the back surface of a table panel; the upper ends of the pull pipes of the two front table legs are fixed on the left side and right side of a table bucket, a supporting plate is fixed on the upper edge of the table bucket, and the front edge of the table panel is arranged on the supporting plate; both the table panel and the supporting plate can be lifted by pulling the pull pipes; the table panel slides back and forth on the supporting plate when the table panel or the supporting plate is separately lifted, so that the tilt degree of the table panel can be changed; oblique bracing plates at the lower ends of the pull pipes are used for positioning; the high ends of the bracing plates are propped against the inner walls of the pull pipes, and the low ends of the bracing plates are propped against the inner walls of the table legs; the low ends of the bracing plates are connected with the lower ends of connecting rods, connecting levers are connected to the upper ends of the connecting rods, and the low ends of the bracing plates are loosened downwards for lifting adjustment; after adjustment, the low ends of the bracing plates are pulled to ascend through the connecting levers to support the inner walls of the table legs again; due to the arrangement of the supporting plate, the defects of difficult operation and inconvenient fetching in the prior art are overcome; due to the arrangement of the connecting levers, the bolt screwing angle during adjustment is changed and the operation is convenient; besides, other defects are overcome.

The invention provides hollow carbon nano-particles and a wave-absorbing material prepared therefrom. A preparation method of the hollow carbon nano-particles comprises the steps of mixing aniline, pyrrole, a non-ionic surface active agent and water to obtain a first solution; carrying out ice bath on an ammonium persulfate solution and adding the ammonium persulfate solution to the first solution to obtain a second solution; reacting the second solution, carrying out suction filtration, washing and freeze drying to obtain a head product; and carrying out carbonization treatment on the head product to obtain the hollow carbon nano-particles. A preparation method of the wave-absorbing material comprises the steps of adding graphene, the hollow carbon nano-particles and polypropylene to a torque rheometer for banburying to obtain a mixture; and carrying out hot pressing and cold pressing on the mixture to obtain the wave-absorbing material. By adopting the graphene and the hollow carbon nano-particles as wave-absorbing media and polypropylene as a carrier, the prepared wave-absorbing material can reach the effective absorption effect on an electromagnetic wave, and meanwhile, a series of advantages of low density and fatigue resistance of the polypropylene material are also integrated.

The invention discloses an optical film defect laser damage threshold test method. According to the method, after a laser beam passes through an attenuator and arrives at a beam splitter, and the laser beam in the transmission direction of the beam splitter passes through a focusing lens and arrives at a metal film; a CCD camera records a spot position where the laser irradiates on the surface ofthe metal film and a laser damage point coordinate where the laser irradiates on the surface of the optical film; and a scanning electron microscope records the longitudinal depth position of the defect damage point of the optical film in the irradiation of the laser and completes a defect damage point lateral energy density subdivision and longitudinal electric field normalization processing-combined analysis. In an optical film defect laser damage threshold test in the prior art, randomly-distributed defect damage points and laser energy density of Gaussian distribution in a laser spot are considered to be uniformly-distributed damage points and laser energy density equivalently, and influence on the defect damage point caused by the electric field distribution of the optical film is ignored, and as a result, many problems are brought about, while with the optical film defect laser damage threshold test method of the invention adopted, the above problems can be solved, and test accuracy can be improved.

Production of magnesium-base and hydrogen-storage alloy and composite material by laser sintering method is carried out by mixing elementary metal or hydrogen-storage alloy powders by ball mill, pressing mixed alloy biscuit, loading at 20-30MPa for 30 seconds, laser sintering by CO2 laser at 500-1600W, inducing into circulation water and cooling. The scanning speed ratio reaches to 100-120mm / min and diameter of light spot is 3-5mm. It's cheap, has less consumption, more yield and shorter sintering time, better performance.

The invention discloses a system for testing a defect laser-damaged threshold of an optical thin film, and the system comprises a laser, an attenuator, a beam splitter, an energy meter, a beam qualityanalyzer, a focusing lens, a CCD camera, a metal film, an optical thin film, a moving platform, a scanning electron microscope and a computer, wherein the laser, the attenuator, the beam splitter, the energy meter, the beam quality analyzer, the focusing lens, the CCD camera, the metal film, the optical thin film, the moving platform, the scanning electron microscope and the computer are sequentially placed according to an optical path. A laser beam emitted by the laser passes through the attenuator to reach the beam splitter. The laser beam in the transmission direction of the beam splitterpasses through the focusing lens to reach the metal film, and the CCD camera records the spot position of the laser irradiation on the surface of the metal film and the coordinates of the laser damagepoint when laser irradiation is on the surface of the optical thin film. The scanning electron microscope records the longitudinal depth position of the laser damage point of the optical thin film, and completes the combination analysis of the subdivision of the lateral energy density of the defect damage point and the normalization processing of a longitudinal electric field. The system can solve a problem caused by a condition that the peak energy density is taken as the defect damage density, thereby improving the testing precision.

The invention relates to a preparation method of a phosphorus-doped carbon-loaded molybdenum-tungsten carbide electrochemical hydrogen evolution catalyst, and belongs to the technical field of electrocatalytic materials. According to the invention, MoWCu multi-element metal-based MOF is used as a precursor, and then high-temperature heat treatment is carried out to obtain the catalyst; through nano confinement carbonization of an organic ligand and in-situ conversion of metal center ions, a component-controllable multi-element metal carbide / phosphorus-doped carbon nano composite structure is synthesized, so that an efficient electrochemical hydrogen evolution catalyst is created; the preparation method is simple in process, agglomeration of molybdenum-tungsten carbide nanoparticles is limited to a great extent, repeatability is good, and mass production is easy; and the catalyst shows good performance in an electro-catalytic hydrogen evolution reaction (HER) under an alkaline condition, and has a certain application prospect.

The invention discloses nitrogen-doped graphene for in-situ growth of a self-assembled denitration sulfur-resistant catalyst, and a preparation method thereof. The preparation method comprises the following steps: taking graphene oxide as a precursor, preparing modified nitrogen-doped graphene from 2,4,6-triaminopyrimidine and cyanuric acid, and growing a ternary Mn-Ce-SnOx catalyst on the surfaceof the modified nitrogen-doped graphene as a catalyst carrier in situ. The self-assembled ternary Mn-Ce-SnOx catalyst is uniformly and firmly loaded on the surface of the modified nitrogen-doped graphene in a surface in-situ growth manner, so that the obtained composite material has good sulfur resistance while having efficient denitration capability.

The invention discloses a method for preparing Mg nano particles under a carbon source atmosphere. An Mg block is heated to evaporate through an electric arc under the mixed atmosphere of an inert gas and a carbon source gas, the Mg steam is separated from a heating area, nucleated and condensed to form Mg nano particles, and the Mg nano particles are passivated to form nano Mg particles in a particle diameter distribution range of 20 to 50 nanometers. The carbon source gas is decomposed under the action of arc plasma in the method, and the generated carbon is covered on the surface of the magnesium particles to inhibit the generation of magnesium oxide and inhibit the agglomeration of the magnesium particles, and meanwhile, the shape and the structure of the magnesium nano particles can be controlled by adjusting the content of the carbon source gas. The method is simple in equipment, high in synthesis speed and low in cost; and the prepared Mg nano particles have high purity and excellent mechanical property in hydrogen absorption and release when being used as a hydrogen storage material.

The invention relates to a method for preparing a polycrystalline ultra-thin metal film and two-dimensional nano pattern. The method comprises a step of preparing a two-dimensional array structure formed by units with special morphology by using UV photolithographic process, and forming a polymer mask, a step of realizing the dense self-assembly of a monodisperse silver nano plate at a substrate through an ascorbic acid AA modified high yield silver nano plate solution, a step of removing the polymer mask through a developer, and forming a patterned self-assembled silver nano plate array on the substrate, a step of removing a silver nano plate coating on the substrate through a physical or chemical method, and a step of forming a (quasi) continuous polycrystalline ultra-thin metal film and two-dimensional nano pattern through continued growth. According to the method, the large-scale preparation of special plane structure sub wavelength devices is realized, the key problem of large area metal thin film optoelectronic device application is solved, the loss of the device is reduced greatly, the performance of the device is improved, the preparation of an ultra-thin continued metal film with the minimum of 10 nm is realized, and the method is a breakthrough of existing preparation technology.

The invention relates to a method for preparing a metal / metal oxide composite electrocatalyst. The method comprises the following steps: (a), growing a metal oxide on a conductive carrier; (b), assembling the metal oxide used as a working electrode, a lithium sheet used as a counter electrode and electrolyte to form a lithium ion half cell; circularly charging and discharging until the dischargingstate is the final state; (c), taking out a product processed by the step (b), washing, and drying. According to the method, lithium ion induced phase transformation reaction is carried out to transform the metal oxide into a metal phase, so that the obtained metal / metal oxide composite material is rich in interface, few in defects and outstanding in conductivity; when the metal / metal oxide composite material is treated as an electrolyzing water catalyst, the catalyzing activity bit density is greatly increased; the substance transferring in the electro-catalysis reaction is speed up, and thus the catalyzing activity is outstanding. The method is generally suitable for a plurality of metal oxides; compared with an existing composite metal oxide synthesizing method, the method is simple, easy to carry out, low in price, high in efficiency, high in controllability, and high in repeatability.

A two component composition for making chemical mechanical polishing pad for polishing a semiconductor substrate is provided comprising a liquid aromatic isocyanate component having an unreacted isocyanate (NCO) concentration of from 15 to 40 wt. %, based on the total solids weight of the aromatic isocyanate component, such as methylene di(phenylisocyanate) (MDI), a liquid polyol component of a polyol having a polyether backbone and having from 5 to 7 hydroxyl groups per molecule, and a curative of one or more polyamine or diamine, wherein the reaction mixture comprises 50 to 65 wt. % of hard segment materials, based on the total weight of the reaction mixture. The composition when mixed cured to form a polyurethane reaction product. Also provided are CMP polishing pads made from the polyurethane reaction product by spraying the composition into a mold.