46results about How to "Meeting the needs of industrial applications" patented technology

The invention discloses a CHA molecular sieve, a synthesis method thereof, and a denitration SCR catalyst synthesized by using the CHA molecular sieve. In the CHA molecular sieve, the molar ratio of silicon dioxide to aluminum oxide ranges from 5 to 75, the grain size ranges from 0.3 micrometer to 2 micrometers, after CHA molecular sieve raw powder is subjected to saturated steam treatment at thetemperature of 600 DEG C to 850 DEG C, tetra-coordinated aluminum accounts for more than or equal to 92 percent of the total aluminum amount, and the hexa-coordinate aluminum accounts for less than orequal to 8% of the total aluminum amount. The synthesis method comprises the step of synthesizing by using a composite organic template agent formed by a quaternary ammonium onium compound containingtetrahydronaphthalene or decahydronaphthalene groups and an N, N, N-dimethyl ethyl cyclohexyl quaternary ammonium onium compound. The molecular sieve disclosed by the invention has high hydrothermalstability under the condition of not having a large grain diameter, and the SCR catalyst disclosed by the invention also shows high nitrogen oxide reduction characteristics after being exposed at hightemperature and high humidity, and particularly shows high nitrogen oxide reduction characteristics in a temperature range of 200-550 DEG C.

The invention discloses a CHA type aluminum-silicon molecular sieve and a preparation method and application of an SCR catalyst, and belongs to the field of chemical synthesis technology and application thereof. The CHA type aluminosilicate zeolite molecular sieve is synthesized by adopting an N,N,N-trialkylbicyclo[2.2.2]octylammonium compound as an organic template agent, wherein the molar ratiorange of silicon dioxide to aluminum oxide in the product is 6-80, the average grain diameter is less than or equal to 500 nm, the total specific surface area is more than or equal to 400m2/g, the total pore volume is more than or equal to 0.20 ml/g, the micropore volume is not less than 0.10 ml/g, and the grain diameter in the crystal face (-210) direction of the molecular sieve is 50-160 nm. After hydrothermal treatment of the molecular sieve at 600-800 DEG C, the tetra-coordinated aluminum accounts for more than or equal to 90% of the total aluminum amount, and the hexa-coordinated aluminumaccounts for less than or equal to 10% of the total aluminum amount. The molecular sieve provided by the invention has high hydrothermal stability without large crystal grains, shows high nitrogen oxide reduction characteristics, and especially shows a catalyst with high nitrogen oxide reduction characteristics in a temperature range of 200-550 DEG C.

The invention discloses a simplified multi-pulse rectifier based on a double-switch power electronic phase-shifting transformer, and belongs to the technical field of power electronics. The simplifiedmulti-pulse rectifier solves the problem that an existing isolation type phase-shifting transformer is large in size/weight, meanwhile, the pulse number of the rectifier is multiplied in a simple mode, input current harmonic waves are effectively restrained, and continuous adjustment of the output voltage of the rectifier is achieved. The simplified multi-pulse rectifier comprises a first group of rectifier bridges with clamping circuits, a second group of rectifier bridges with clamping circuits, a phase-shifting transformer, a first group of three-phase rectifier bridges, a second group ofthree-phase rectifier bridges, a balance reactor with a secondary winding, a single-phase rectification circuit, a post-stage filter circuit and a control circuit, wherein a turn ratio of a primary side winding to the secondary side winding of the balance reactor with the secondary side winding is 0.246, and at the moment, the balance reactor with the secondary side winding and the single-phase rectification circuit form a pulse multiplication balance reactor which is used for realizing the pulse number multiplication of the rectifier. The simplified multi-pulse rectifier is mainly used for converting three-phase alternating current into direct current.

The invention discloses a preparation method of a multi-grain-scale lamellar structure aluminum alloy. The preparation method comprises the steps of pretreatment, casting, plastic deformation, multi-grain scale formation and the like, two or more kinds of aluminum alloys with different alloy components are selected, solid-liquid embedding casting is carried out, and the multi-layer composite aluminum alloy is formed. Plastic deformation and subsequent annealing treatment are performed to form phases with different grain sizes between adjacent layers to obtain the multi-grain-scale reinforced lamellar structure aluminum alloy material.

The invention discloses an AEI/AFX topological structure symbiotic composite molecular sieve and a preparation method of an SCR catalyst, the AEI/AFX topological structure symbiotic composite molecular sieve is formed by symbiosis of AEI and AFX topological structure molecular sieves, and a characteristic diffraction peak exists at a 2 theta angle in an X-ray diffraction phase spectrogram of the molecular sieve with a symbiotic composite structure; wherein the molar ratio of silicon to aluminum oxide in the symbiotic composite molecular sieve is 10-200. In the preparation process of the symbiotic composite molecular sieve, a composite template agent is adopted; an FAU type silicon-aluminum molecular sieve is used as an aluminum source and a silicon source, other silicon sources and alkalisources can be combined to form mixed sol, an AEI/AFX symbiotic structure molecular sieve is synthesized through dynamic crystallization according to temperature sections, and then the AEI/AFX symbiotic structure molecular sieve exchanges with soluble metal salt cations to obtain the SCR molecular sieve catalyst. The SSZ-39 with the AEI structure and the SSZ-16 with the AFX structure form the symbiotic composite molecular sieve; the composite molecular sieve has more reasonably distributed acidity and good hydrothermal stability, has good catalytic activity and excellent service life in SCR reaction of NOx-containing gas discharged by a moving source and a fixed source, and can well meet the standard requirements of tail gas emission.

The invention discloses a nitrogen oxide purification CHA zeolite molecular sieve as well as a preparation method and application of a catalyst thereof, and belongs to the field of chemical synthesistechnologies and application thereof. The CHA zeolite molecular sieve is synthesized by adopting an N,N,N-trialkyl-quinuclidine-4-quaternary ammonium onium compound as an organic template agent, the molar ratio range of silicon dioxide to aluminum oxide is 6-80, the average grain diameter is less than or equal to 500 nm, the total specific surface area is more than or equal to 400m2/g, the total pore volume is more than or equal to 0.20 ml/g, the micropore volume is more than or equal to 0.10 ml/g, and the grain diameter in the crystal face (-210) direction of the molecular sieve is 50-160 nm.After hydrothermal treatment of the molecular sieve at 600-800 DEG C, the tetra-coordinated aluminum accounts for more than or equal to 90% of the total aluminum amount, and the hexa-coordinated aluminum accounts for less than or equal to 10% of the total aluminum amount. The molecular sieve provided by the invention has high hydrothermal stability without large crystal grains, shows high nitrogen oxide reduction characteristics after being exposed at high temperature and high humidity, and especially shows a catalyst with high nitrogen oxide reduction characteristics in a temperature range of 200-550 DEG C.

The invention relates to a chopped carbon fiber toughened silicon carbide composite material and a preparation method thereof. The preparation method comprises the following steps of: reacting chopped carbon fibers with a silane coupling agent, absolute ethyl alcohol and deionized water to obtain coupling agent grafted chopped carbon fibers; mixing the coupling agent grafted chopped carbon fibers with an organic solution of a high-carbon-residual-rate binder to obtain high-carbon-residual-rate binder coated chopped carbon fibers; mixing the high-carbon-residual-rate binder coated chopped carbon fibers with silicon carbide powder to obtain mixed powder; performing dry pressing on the mixed powder to obtain a biscuit, and performing degreasing treatment to obtain a preform; and carrying out reactive infiltration on the preform to obtain the chopped carbon fiber toughened silicon carbide composite material.

The invention belongs to the field of material preparation, and particularly relates to a preparation method of a multi-crystal-granule-size multi-layer high-entropy alloy. The preparation method of the multi-crystal-granule-size multi-layer high-entropy alloy comprises the following steps of (1) pretreating: selecting more than two high-entropy alloys, wherein each high-entropy alloy is a single phase and cannot happen phase change in the heating process, and each high-entropy alloy at least contains one FCC and BCC-structure single phase; (2) casting: carrying out solid-liquid inlaying and casting on the liquid-state high-entropy alloy and the solid-state high-entropy alloy, and forming a multi-layer high-entropy alloy; (3) rolling: cutting the multi-layer high-entropy alloy to obtain a multi-layer high-entropy alloy block, and rolling to obtain a rolling-state multi-layer high-entropy alloy; and (4) forming a multi-crystal-granule-size: carrying out heat treatment on the rolling-state multi-layer high-entropy alloy, and obtaining the multi-crystal-granule-size multi-layer high-entropy alloy. The preparation method of the multi-crystal-granule-size multi-layer high-entropy alloy provided by the invention adopts a multi-alloy solid-liquid mixed casting and forming method, the prepared high-entropy alloy has toughness and strength of a soft phase and a hard phase to a certain degree, and the high-strength high-toughness double-system or multi-system refined crystalline strengthening high-entropy alloy with a favorable combination property is obtained.

The invention belongs to the field of material preparation, and particularly relates to a multi-extrusion device for preparing a layered isomeric magnesium alloy and a method for preparing the layeredisomeric magnesium alloy by utilizing the device A plurality of as-cast magnesium alloy ingot blanks subjected to homogenization treatment are cut into square shapes and subjected to preheating treatment, then the square-shaped as-cast magnesium alloy ingot blanks are put into a mold, the blanks are pressed into a cavity under the acting force applied by a punch, and the punch is extruded to continuously move downwards to push the alloy blanks to continuously enter the cavity. After the cavity is completely filled with a blank, an extrusion insert is taken out, an insert with a larger extrusion ratio is replaced, and a limiting block at the outlet part of the blank is adjusted upwards, so that the magnesium alloy which is forced to be extruded obtains enough space, and the extrusion experiment is repeated. In addition, the insert is replaced with the insert with the larger extrusion ratio, the position of the limiting block is adjusted upwards again, and then the extrusion experimentis repeated again. Through repeating the processes, the layered isomeric magnesium alloy with excellent comprehensive performance, high strength and high toughness is finally obtained.