391results about How to "Slow down the spread" patented technology

The invention discloses a halogen-free cleaning-free rosin flux, and preparation and application thereof, and particularly relates to a flux suitable for surface mount lead-free welding paste, preparation of the flux and application of the flux. The flux comprises 20-50% (mass fraction, the same below) of rosin, 5-25% of film-forming agent, 30-50% of high boiling solvent, 3-8% of activator and 2-5% of thixotropic agent, and the flux does not contain any halogen. In order to control growth of interface IMC (intermediate compound) during welding, 0.3-1% of combined inhibitor is added. The welding paste prepared with the flux and lead-free tin-silver-copper powder has the advantages of excellent printing performance, fine weldability, less post-weld residue, thin and even welding spot interface IMC and excellent mechanical property, and is capable of meeting the requirement of high-end electronic products on packaging.

A three-element catalyst for cleaning the tail gas of car features that the cellular cordierite ceramics modified by the RE tailing mixture or transition metal oxide is ued as the first carrier, the internal and external modified alumina coating layers are used as the second carrier, and the noble metal Pt, Rh or Pd is used as its active component.

The invention relates to a silver alloy wire and a preparation method thereof. The silver alloy wire is prepared from the following components of 0.5-10 percent of Au, 0-1 percent of Pt, 1-6 percent of Pd, 0-1 percent of Rh, 0-1 percent of Cu, 0-500ppm of Ln, 0-200ppm of Ce, 0-0.5 percent of Al, 0.7-3 percent of Ti, 0-0.2 percent of Si, 0-0.3 percent of Zn, 0-1 percent of Sn, 0-10 percent of Be and the balance of Ag. A directional continuous casting process is adopted. The prepared silver alloy wire overcomes the problem that the bonded silver wire is easily subjected to sulfur corrosion in the prior art, and has a series of other excellent characteristics.

The invention relates to a sealing coating for a thermally stressed component, particularly a turbine component, for protection from corrosion and/or oxidation and/or erosion. To improve the life of the protective coating or of the component, the protective coating has a single-layer or multilayer sealing coating of an amorphous material.

The invention discloses a protective sealing door for an underground refuge chamber. The protective sealing door comprises a door frame and a door plate, wherein the door plate is arranged on the door frame through a rotation shaft; a locking mechanism for locking the door plate on the door frame is arranged on the door plate, a plurality of first reinforcing ribs for reinforcing the strength of the door plate are arranged in the door plate; heat-insulating materials, namely aerogel heat-insulating felts are filled among the reinforcing ribs; at least two annular sealing rings, namely flame-resisting sealing rings are arranged at the joint of the door plate and the door frame; and the periphery of the door plate is locked by the locking mechanism. According to the protective sealing door, the aerogel heat-insulating felts which can bear the temperature of 1,400 DEG C to the maximum are filled in the door plate, so that the door plate can resist high temperature generated during explosion, and the high temperature is insulated out of the refuge chamber; at least two sealing rings which are made of flame-resisting, anti-static, high temperature-resisting and oil-resisting materials are arranged on the contact surface of the door plate and the door frame, so that the protective sealing door has a good sealing effect.

The invention relates to a thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane and a preparation method thereof, relating to a medicine-loading electro-spun fibrous membrane and a preparation method thereof and aiming to solve problems of poor mechanical property of existing poly N-isopropylacrylamide medicine-loading electro-spun fibrous membrane and no temperature sensitivity of a polyurethane medicine-loading electro-spun fibrous membrane. The thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane is prepared by poly N-isopropylacrylamide, polyurethane, N,N-dimethylformamide and a medicine; the preparation method comprises the following steps: 1, preparing static spinning solution; 2, dissolving the medicine so as to obtain the static spinning solution containing the medicine; 3, carrying out electrospinning; and 4, carrying out dry treatment to obtain the thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane. According to the invention, the preparation method is mainly used for preparing the thermo-sensitive poly N-isopropylacrylamide/polyurethane medicine-loading electro-spun fibrous membrane.

The invention relates to a die-casting heat resistant magnesium alloy containing Ca and heavy rare earth element Gd and a preparation method thereof, pertaining to the metal material technical field. The components and weight percentage thereof of the alloy are: 3.0 to 8.0 percent of Al, 0.1 to 3.0 percent of Ca, 0.1 to 3.0 percent of Gd, 0 to 0.5 percent of Mn, lower than 0.02 percent of impurity elements and the rest is Mg. The preparation method of the alloy comprises the following steps: the materials are weighed, and industrial pure Mg is heated under the protection of the mixed gas of N2 and 0.2 percent of SF6; after Mg is wholly melted, industrial pure Al, industrial pure Ca and Al-Mn interalloy are added at the temperature of 650 to 680 DEG C, Mg-Gd interalloy is added at the temperature of 660 to 680 DEG C, the temperature is increased to 740 to 760 DEG C, and when the Mg liquid is cooled to 670 to 690 DEG C, the mixture carries out die casting. The preparation method of the invention has the advantages of low cost and high production efficiency, obviously increases the tensile strength, the yield strength, the elongation percentage and the creep resistance of the alloy at room temperature, and has excellent die-casting performance.

The invention provides a process method for preparing an aluminide penetrating layer on the surface of pure copper or a copper alloy by combining the thermal spraying technology and the thermal treatment technology, which comprises the following steps: firstly, spraying a layer of pure aluminium coating on the surface of a copper product through arc; secondly, performing shot blasting and sealingagent coating treatment on the surface of the coating; and finally, performing thermal treatment at a temperature of between 800 and 900 DEG C, maintaining the temperature for 2 to 4 hours, and obtaining an aluminide layer over 3mm on the surface of the pure copper. The aluminide layer prepared by the method has good combination with a copper substrate, good antioxidant performance and good wear resistance. The method can prepare the aluminide penetrating layer, and also can prepare aluminium-molybdenum, aluminium-silicone, aluminium-chromium binary or multi-metallic diffusion layers.

The invention provides a 600MPa hot-rolled ribbed steel bar and a preparation method thereof. The steel comprises the following chemical components in percentage by weight: 0.06-0.15% of C, 0.2-0.5% of Si, 1.2-1.6% of Mn, less than or equal to 0.04% of P, less than or equal to 0.04% of S, 0.001-0.04% of B, 0.03-0.05% of Nb, 0.02-0.05% of V, 0.01-0.04% of Ti, 0.005-0.009% of N, and the balance of Fe and inevitable impurities. The preparation method of the 600MPa hot-rolled ribbed steel bar comprises the steps of molten iron desulphurization, converter smelting, nitrogen blowing, continuous casting, square billet heating, rolling, cooling control and cooling bed air-cooling. The steel not only has good comprehensive mechanical properties, but also has better cold bending properties.

The invention discloses a method for homogenizing, solidifying and forming polyacrylonitrile precursor. By adopting a wet spinning technology, a polyacrylonitrile spinning solution trickles in a coagulating bath to be subjected to double diffusions through solvent and precipitator and then solidified and separated so that the polyacrylonitrile precursor is formed. According to the method disclosed by the invention, an ammonia-containing compound is added in the a coagulating bath; the ammonia-containing compound is served as a third component and can be used for retarding the double-diffusion speed in the solidification process of the polyacrylonitrile spinning solution; therefore, the solidifying and forming homogenization is realized; and the high-performance polyacrylonitrile precursor and carbon fibre can be obtained.

The invention discloses a magnesium aluminate spinel enhanced magnesia-based foamed ceramic filter with capability of realizing sintering at low temperature, excellent chemical stability and excellentthermal shock resistant performance, and a preparation method thereof. The preparation method comprises the following steps that (1) 10 to 20 percent of nanometer alumina sol, 0.8 to 1.5 percent of rheological agents and the balance of magnesium oxide ceramic powder containing a nanometer aluminum oxide sintering aid are proportioned; deionized water is added; ball milling and uniform mixing areperformed; then, through vacuum exhaust, ceramic slurry with the solid content being 60 to 70 percent is prepared; (2) a polyurethane foamed plastic template is soaked into the ceramic slurry; the polyurethane foamed plastic template is extruded through a roller press for removing the redundant leaching hanging slurry; then, biscuit is prepared; then, the biscuit is heated to 80 to 120 DEG C for drying; (3) the dried biscuit is put into a sintering furnace; the temperature is raised to 1400 to 1600 DEG C; high-temperature sintering is performed; cooling is performed along with the furnace to room temperature; the magnesia-based foamed ceramic filter is obtained.

The invention relates to a nickel-based high temperature alloy, a preparation method thereof as well as application thereof in a spark plug electrode. The nickel-based high temperature alloy contains the following components in percent by weight: 0.04%-0.06% of C, 19%-21% of Cr, 7%-9% of W, 5%-7% of Mo, 1%-2% of Ti, 0.5%-2% of Al, 0.004%-0.006% of B, 0.03%-0.05% of Zr, 0.7%-0.9% of Fe, 0-3% of Nb, 0-1% of Y, and the balance of Ni and inevitable impurities. The preparation method of the nickel-based high temperature alloy comprises the following steps of: mixing the components in a vacuum electric-arc melting furnace according to a proportion, smelting, getting out and forming; heating up to 1200 DEG C in a heating furnace, carrying out thermal-insulation solid-solution treatment for 4 hours, and carrying out air-cooling; and carrying out thermal-insulation aging treatment for 10 hours at 800 DEG C, and carrying out air-cooling to prepare the nickel-based high temperature alloy. The nickel-based high temperature alloy disclosed by the invention has good high-temperature oxidation resistance and corrosion resistance, and can be applied to the spark plug electrode material so as to prolong the service life of an electrode and the service life of a spark plug.

To provide an ignition timing control system for an internal combustion engine, which is capable of ensuring stable combustion without causing a misfire or knocking, by properly setting ignition timing in the compression stroke injection mode, thereby making it possible to improve drivability. The ignition timing control system for the engine 3 that directly injects fuel into cylinders 3a and is operated by switching the fuel injection mode between an intake stroke injection mode and a compression stroke injection mode comprises fuel injection timing-setting means 2 for setting a fuel injection timing INJOBJ according to an engine speed NE of the engine 3 and a fuel injection amount GFUEL, basic value-setting means 2 for setting a basic value IGBASE of ignition timing according to the engine speed NE of the engine 3 and the fuel injection timing INJOBJ, and ignition timing-setting means 2 for setting ignition timing IGCOMP in the compression stroke injection mode by correcting the basic value IGBASE according to a detected air-fuel ratio AF.

The invention belongs to the technical field of metal heat treatment, and relates to a production process for improving the intergranular corrosion resistance of 6 series aluminum alloys. The 6-seriesaluminum alloys are prepared from the raw materials: 0.5% to 0.9% of Si, less than or equal to 0.35% of Fe, less than or equal to 0.30% of Cu, less than or equal to 0.50% of Mn, 0.4% to 0.7% of Mg, less than or equal to 0.30% of Cr, 0.1% of Ti, less than or equal to 0.05% of single impurity, less than or equal to 0.15% of total impurity and the balance of Al; a preparation method includes the steps of ingredient melting and casting, homogenization, extrusion, solution quenching, stretching, two-stage aging and detection; and the two-stage aging system is (175-185 DEG C)*(7-9h)+200 DEG C*(3-5h), and the heating time from the first-stage aging to the second-stage aging does not exceed 15min. The two-stage aging is a best aging mode, and the tensile strength and the intergranular corrosion resistance are the best match.

The invention relates to a concrete-curing agent applicable to a strong-wind arid area and a preparation method thereof. The curing agent is prepared through the following steps of: by using an organic/inorganic composite system with an organic-silicon/fluorine modified propyl-benzene emulsion and active aluminum-silicate modified sodium-silicate solution as a main fluid and adopting a siloxane organic-silicon compound with a certain reactive group as a cross-linked component, compounding with a film-forming aid, a defoaming agent, a thickening agent, a wetting and dispersing agent, a mildew-proof agent, a flatting agent, an ultraviolet-resisting agent and deionized water under the condition at a normal temperature. The production process of the concrete-curing agent is simple, and reaction conditions are easy to control. The water-resisting property, the scrubbing-resisting property, the durability and the flexibility of a film after the film of the curing agent is formed are improved by introducing the propyl-benzene emulsion of organic silicon/fluorine onto a high-molecular chain; and the compactness of the film is enhanced by introducing the modified sodium-silicate solution, thereby the water evaporation of a concrete surface is greatly reduced. The curing agent has the technical characteristics that the curing agent can be sprayed after concrete is finished, the film-forming speed is high, the water retention rate is high, ultraviolet rays are resisted, and the like, and is applicable to the concrete curing of western strong-wind arid areas.

A membrane electrode assembly for a fuel cell, a method of preparing the same, and a fuel cell using the membrane electrode assembly for a fuel cell. The membrane electrode assembly includes an anode comprising an anode substrate, an anode diffusion layer, and an anode catalyst layer having pores; a cathode comprising a cathode substrate, a cathode diffusion layer, and a cathode catalyst layer having pores; and an electrolyte membrane interposed between the cathode and the anode, wherein the anode diffusion layer is hydrophilic and the cathode diffusion layer is hydrophobic, and the average diameter of the pores of the anode catalyst layer is smaller than the average diameter of the pores of the cathode catalyst layer. In the membrane electrode assembly, air can be easily supplied to the cathode and water can easily flow out of the cathode, thereby obtaining high performance of the membrane electrode assembly, and the anode catalyst layer has relatively small pores, thereby improving durability of the anode and reducing the diffusion speed of methanol in the anode catalyst layer to maintain the initial performance of a battery for a long time.

The invention discloses a hard carbon-metal oxide-soft carbon composite material and a preparation method and application thereof. The preparation method comprises the steps of firstly, performing a hydrothermal method on hydrocarbon in a reaction kettle to prepare a hard carbon precursor; secondly, pre-coating the hard carbon precursor and a titanium salt, placing asphalt in a muffle furnace for low-temperature pyrolysis reaction to obtain a soft carbon precursor; and finally, fully mixing the pre-coated hard carbon precursor and the soft carbon precursor, and performing high-temperature pyrolysis reaction under protection of an inert gas to obtain the product, wherein the product is the hard carbon-metal oxide-soft carbon composite material. The material can be used as a negative active material of a sodium ion battery. The preparation method is wide in raw material source and low in cost, and the prepared hard carbon-metal oxide-soft carbon composite material has the advantages of large reversible capacity, high initial charge-discharge coulombic efficiency, good cycle property and the like in the sodium ion battery.

The invention provides a water covering type explosive welding method of a metal compound. The method comprises the steps of polishing a base plate (1) and horizontally arranging on a clay foundation (5); uniformly arranging a plurality of supports (7) on the base plate; horizontally arranging a compound plate (3) on the base plate through the plurality of supports; adhering an explosive frame (2) to the surrounding of the compound plate through an adhesive bag in the length and width directions; uniformly paving explosive (6), wherein the explosive is paved and controlled to be 2.4 to 4.0g/cm<2> in height H; arranging a water box (8) on the explosive frame and staggering to form a gap for storing detonator (1); slowly pouring water (9) into the water box and keeping the depth less than or equal to H/2; detonating the explosive through the detonator during explosive welding. According to the method, water in the water box can slow down the explosive energy upwards diffusing and can also raise the explosive utilization rate during explosive welding; meanwhile, water can be atomized when the explosive is detonated, and therefore, a large amount of poisonous gas generated by explosive welding can be absorbed by the atomized water, and moreover, lots of clay dust and explosion-caused dust can be collected so as to reduce the pollution to the working environment.