38results about How to "Meet the requirements of the preparation" patented technology

The invention discloses a method for purifying a cefazolin acid, which is implemented by preparing a crude cefazolin acid product with a content of less than 97% into a sodium salt firstly; then, carrying out adsorption on the sodium salt by using a macroporous resin so as to remove impurities; and finally, reducing the sodium salt to an acid, so that the content, individual impurity and color grade of the obtained cefazolin acid satisfy the demands of being directly used for preparing cefazolin sodium by using a freeze-drying method; and the cefazolin acid can be directly used. The method disclosed by the invention overcomes the defects that single purification in existing purification methods can not meet the requirements of use.

The present invention relates to a preparation method of serinol, belonging to the field of serinol preparation technology by using reduction reaction. Said serinol is an important intermediate body for preparing nonionic X-ray contrast agent iopamidol. Said invention uses 2-nitro-1,3-propanediol sodium salt as raw material, uses hydrazine hydrate as reducing agent and uses palladium / carbon as catalyst to prepare serinol at normal pressure.

The invention belongs to the field of civil engineering and relates to a preparation device of a geotechnical three-axis sand sample. The preparation device comprises a funnel, a sand falling switch, an upper organic glass pipe, a dispersion device, a dispersion sheet, a lower organic glass pipe, a splitting mold and a three-axis chamber base, wherein the lower organic glass pipe is arranged on the three-axis chamber base through the splitting mold; the splitting mold is provided with a lower air exhausting hole; the dispersion device comprises an upper dispersion device and a lower dispersion device, each having a convex-shaped section; the upper dispersion device sleeves the outer part of the upper organic glass pipe and the lower dispersion device sleeves the outer part of the lower organic glass pipe; the dispersion sheet is embedded between the upper dispersion device and the lower dispersion device; the upper dispersion device and the lower dispersion device are arranged back to back and are connected through a connection bolt; the upper organic glass pipe is communicated with the lower organic glass pipe through the dispersion sheet in the dispersion device; the funnel is arranged at the top of the upper organic glass pipe and is communicated with the upper organic glass pipe through the sand falling switch; and the upper organic glass pipe is provided with an upper air exhausting hole. The preparation device of the geotechnical three-axis sand sample has the advantages that the sand sample with good uniformity can be prepared and the operation is convenient.

The invention provides a poly-sulfur positive electrode material. Steps for preparing the poly-sulfur positive electrode material include 1), carrying out polymerization reaction on simple sulfur substances in molten states and thiuram organic polymerizing agents; 2), grinding and smashing reaction products after the polymerization reaction is completely carried out. The thiuram organic polymerizing agents are a type or a plurality of types of thiuram monosulfide, thiuram disulfide and thiuram polysulfide. The invention further provides a lithium-sulfur secondary battery prepared from the poly-sulfur positive electrode material. The poly-sulfur positive electrode material and the lithium-sulfur secondary battery have the advantages that the material preparation requirements can be met by simple heating equipment, processes for producing the poly-sulfur positive electrode material are convenient to operate and are simple, thiuram is extremely low in cost, and accordingly the poly-sulfurpositive electrode material is low in synthesis cost; macromolecular polymerized sulfide can be polymerized, the related problems such as poly-sulfur dissolution and shuttling of lithium-sulfur batteries can be solved when poly-sulfur is used as a positive electrode of the lithium-sulfur secondary battery, and the lithium-sulfur secondary battery is stable in cycle performance and long in cycle life.

The invention discloses an aluminum columbium tantalum ternary alloy and a preparation method thereof. The aluminum columbium tantalum ternary alloy comprises the following elements by weight percent: 40%-50% of Al, 35%-45% of Nb, and 5%-25% of Ta. The preparation method comprises the following steps of: step one, building a square graphite brick smelting furnace with a graphite brick; step two, placing the built graphite brick smelting furnace in a dry kiln; step three, burdening by using a burdening machine controlled by a computer; step four, igniting the loaded furnace burden with a magnesium chip to carry out smelting, wherein smelting temperature is 2700-3000 DEG C, and smelting time is 1 minute; step five, finishing the alloy by using a grinding machine to remove an oxide skin on the surface of the alloy; and step six, crushing the finished alloy by using a jaw crusher. The alloy and the preparation method of the alloy have the beneficial effects that production cost is low, energy is saved, and the alloy is low in impurity content; and the melting point of the alloy is reduced to be lower than 1650 DEG C, which is capable of fully meeting the requirements for the preparation of a titanium alloy.

The invention relates to a method for preparing an optical fiber preform rod and drawing an optical fiber. It uses a heating furnace device as a heat source, and a quartz crucible container containing SiO 2 A glass-based rod is filled with high-purity quartz sand or a mixture of quartz sand doped with F or B and other elements into the aforementioned container, melted at high temperature and drawn out of the SiO core containing the core. 2 The outer periphery of the glass rod has SiO 2 Optical fiber preforms with cladding or quartz sand mixture outer cladding doped with elements such as F or B can also be directly drawn out of optical fiber products by adjusting the drawing process parameters.

The invention provides a high alloy tool and die steel hollow steel ingot injection molding method and hollow steel ingot and high alloy tool and die steel hollow tube billet preparation method, the hollow steel ingot spray forming method of the present invention includes rolling a steel plate to meet the inner diameter and height requirements The top-closed core cylinder is fixed on the rotatable collection tray in the spray chamber, and the refined high-alloy tool and die steel molten steel is sprayed to the rotating collection tray and core cylinder for atomization deposition, and the spray is used The collecting tray is continuously moved downwards to gradually deposit the sprayed ingots, and the sprayed ingots are air-cooled and then annealed and air-cooled out of the furnace. The hollow steel ingot preparation method of the present invention can make the hollow steel ingot uniform and fine in structure, dense in crystallization, greatly improved in chemical composition and carbide segregation, close to the quality of products obtained by powder metallurgy forming method, and can realize the preparation of hollow steel ingot of high alloy tool and mold steel, and The prepared hollow steel ingot can meet the requirements for the preparation of high-alloy tool and die steel hollow pipes.

The invention discloses a modified silica fume wool and a preparation method and application thereof. The modified silica fume wool is prepared by joint modification of 3-isocyanatopropyltrimethoxysilane and a silane coupling agent as described in formula I. The modified silica fume wool prepared by the invention is modified jointly by two silane coupling agents, which greatly improves the friction resistance of the material. The friction coefficient of the disc brake pad prepared by using the modified silica fume wool as a raw material reaches 0.63, which meets the requirement of Current requirements for the preparation of disc brake pads.