16results about How to "Narrow distribution" patented technology

This invention discloses an environmentally friendly plasticizer using modified lignin as a carrier, a rubber composition, and a method for preparing the same, relating to the field of rubber processing technology. The environmentally friendly plasticizer using modified lignin as a carrier, by weight, comprises the following components: 50 parts modified lignin, 25 parts plasticizing active ingredient, 8 parts dispersant, 5 parts anti-aging agent, and 3 parts stabilizer. The modified lignin is a lignin oligomer containing ester, acetyl, and ether cross-linked structures, with a weight-average molecular weight of 800-1200 Da, a dispersion coefficient ≤1.5, and a carboxyl content ≤0.2 mmol / g. This invention successfully overcomes the technical defects of existing plasticizer carriers, such as high toxicity, difficulty in degradation, and poor compatibility with polymer matrices, providing an environmentally friendly plasticizer using modified lignin as a carrier. This technical solution achieves the dual goals of high-value utilization of lignin and greening of the plasticizer product.

This invention discloses a continuous crystallization apparatus and preparation method for ultrafine ammonium perchlorate. The apparatus consists of a mixing unit, an ultrasonic enhancement unit, a gas-liquid Taylor flow control unit, and a post-processing unit. The preparation method combines solution reaction crystallization, ultrasonic-enhanced mixing, and gas-liquid Taylor flow microscale control. It utilizes the confined space within the Taylor flow liquid section to control crystal growth, providing a uniform and stable growth environment for crystal growth. This effectively avoids the problem of wide crystal particle size distribution caused by uneven supersaturation and wide residence time distribution in traditional stirred crystallizers. It achieves continuous and controllable crystallization of ultrafine ammonium perchlorate, overcomes the defects of wide particle size distribution in traditional methods, and can prepare ultrafine ammonium perchlorate crystals with narrow particle size distribution and small average particle size. It has the advantages of simple and efficient process and high product quality.

The invention discloses a copper-silicon catalyst for plasma treatment as well as a preparation method and application of the copper-silicon catalyst. According to the method, a copper-silicon catalyst precursor prepared by a traditional ammonia distillation method is subjected to dielectric barrier discharge plasma treatment in the atmosphere of H2 / Ar and the like, and traditional high-temperature roasting and reduction processes are replaced. According to the method, efficient reduction and high dispersion of copper can be achieved at the room temperature, the Cu < + > / Cu0 proportion is regulated and controlled, and the strong interaction between metal and a carrier is enhanced. The catalyst is used in a reaction for preparing ethylene glycol through hydrogenation of dimethyl oxalate, the activity, selectivity and stability of the catalyst are higher than those of a traditional heat treatment catalyst, the dimethyl oxalate conversion rate reaches up to 100%, the ethylene glycol selectivity is larger than 97%, and the stability reaches 1000 h or above. The method is simple in process, low in energy consumption and environment-friendly, and has a wide industrial application prospect.

The present invention provides a modified polyolefin resin that can form a coating that exhibits excellent adhesion to a low-polarity base material, especially a poorly adherable polyolefin base material with no surface treatment even when being dried at low temperatures and has flexibility (bendability). Provided is a modified polyolefin resin that is a modified product of a polyolefin resin having a melting point (Tm) by a differential scanning calorimeter (DSC) of 60 to 165°C with a modifier comprising the following (A): (A) a monomer mixture comprising Monomer Group (A-1) and Monomer Group (A-2) with a weight ratio of Monomer Group (A-1) to Monomer Group (A-2) ((A-1) / (A-2)) of 30 / 70 to 50 / 50.

The utility model provides a microsphere preparation device. The microsphere preparation device comprises a coagulation tank, a solidification tank, a shearing machine, a flow speed regulator, a first control valve and a second control valve, the condensation tank is provided with a first feed port, a return port and a discharge port, the solidification tank is provided with a second feed port, the discharge port, the shearing machine and the return port are sequentially connected to form a condensation liquid drop circulation pipeline, and the discharge port, the shearing machine and the second feed port are sequentially connected to form a condensation liquid drop output pipeline; according to the device disclosed by the utility model, microspheres with uniform particle size and narrower particle size distribution range are obtained by circularly shearing condensed liquid drops formed in the condensation tank; the speed of adding the condensed liquid drops into the curing tank can be controlled through a flow speed regulator, so that the microspheres are prevented from gathering in the curing process; and the inclined blades are arranged, so that upward thrust can be generated when the stirring paddle rotates, and the condensed liquid drops are prevented from being gathered and precipitated.

The invention provides a synthesis method of modified polystyrene with controllable molecular weight, which comprises the following steps: S1, dissolving a free radical initiator, a styrene monomer and a modified monomer in a part of an organic solvent to obtain a mixed monomer solution; s2, in a nitrogen atmosphere, heating the rest of the organic solvent to 60-150 DEG C, dropwise adding the mixed monomer solution obtained in the step S1 into the organic solvent at a constant speed to initiate a polymerization reaction, and curing at a constant temperature for 30-120 minutes after dropwise adding for 30-150 minutes; s3, carrying out reduced pressure distillation on the reaction system until the solid content of a product reaches 70% to obtain modified polystyrene; wherein the number average molecular weight of the modified polystyrene is 3000 to 80000. The invention provides a synthesis method of modified polystyrene with controllable molecular weight, which realizes controllable preparation of the modified polystyrene product with the number-average molecular weight in the range of 3000-80000, and obtains the product with narrow distribution and stable solid content.

The present disclosure provides an erasing method of a non-volatile memory and a non-volatile memory, and relates to the technical field of semiconductors. The method comprises: performing a first erasing operation on a target erasing area and then performing a first erasing verification operation to obtain a first erasing verification result of each storage unit in the target erasing area; obtaining a first erasing verification result of the target erasing area according to the first erasing verification result of each storage unit in the target erasing area; in response to the first erasing verification result of the target erasing area being failed, performing a second erasing operation on the target erasing area and then performing a second erasing verification operation to obtain a second erasing verification result of each storage unit in the target erasing area; and determining whether to perform a third erasing operation on the target erasing area according to the number of storage units in the target erasing area whose first erasing verification result and second erasing verification result are both failed. The method narrows the threshold voltage distribution range of the storage unit after the erasing operation.

This invention relates to a method for preparing ultrafine silver powder, the method comprising the following steps: (1) dissolving silver nitrate in deionized water to obtain a metal salt solution, and maintaining the temperature at 30-50°C; (2) dissolving a reducing agent in deionized water and adding a pH adjuster to obtain a reducing agent solution, and maintaining the temperature at 30-50°C; (3) dissolving a dispersant and a dopant in deionized water to obtain a mixed solution, and maintaining the temperature at 30-50°C; (4) adding the mixed solution to the metal salt solution, stirring for 1 min, and then adding the reducing agent solution to the metal salt solution, stirring and reacting to obtain silver powder; (5) washing the silver powder until the conductivity of the washing solution is ≤10 μs, separating the solid and liquid to obtain an Ag powder filter cake; (6) adding a surface coating agent-anhydrous ethanol solution to the Ag powder filter cake, stirring evenly, and then drying, air-dispersing, and sieving to obtain ultrafine silver powder with a particle size of 0.4-0.8 μm. This invention is simple to operate, low in cost, and easy to industrialize. The resulting silver powder product has small particle size, narrow distribution, and good dispersibility.

This invention discloses a high-purity ultrafine spherical silica powder, its production method, and its application, belonging to the technical field of high-value mineral material preparation and high-value utilization of industrial solid waste. The preparation method includes: flotation and acid washing of silica mud to obtain purified silica powder; air jet milling and air jet classification of the purified silica powder to obtain ultrafine silica powder; and feeding the ultrafine silica powder into a plasma reactor in the presence of an oxygen-containing flow, causing simultaneous oxidation and spheroidization to obtain high-purity ultrafine spherical silica powder. The oxygen volume concentration in the oxygen-containing flow is 25-60%; the ratio of the input power of the plasma reactor to the powder feeding rate of the ultrafine silica powder is 15 kWh / kg-50 kWh / kg. Based on the material characteristics of silica mud, this method achieves high-value utilization of silica mud through the synergistic regulation of pretreatment purification, precise particle size control, and energy-coupled spheroidization throughout the entire process, while possessing advantages such as low energy consumption, uniform product particle size, high purity, and good sphericity.

This invention relates to the field of ultra-high molecular weight polyethylene (UHMWPE) technology, specifically disclosing a synthesis process for UHMWPE medical-grade materials. The process includes: activating a catalyst, an external electron donor, and a composite co-catalyst in a dispersion medium under an inert atmosphere, followed by prepolymerization with ethylene; then performing a two-stage heating polymerization, introducing nitrogen to regulate the partial pressure and adding the co-catalyst in the second stage; after the reaction is terminated, the product is obtained through devolatilization, washing, and drying to produce a powder product. The catalyst is a composite support modified with organosilanes and a metal-organic framework, and is prepared by loading magnesium and titanium active components using a specific low-temperature process. This invention achieves precise control over the molecular weight and distribution of the polymer by optimizing the catalyst structure and segmented polymerization process parameters. The resulting UHMWPE exhibits high molecular weight, narrow distribution, low impurity residue, and excellent biocompatibility, making it suitable for high-end medical products such as artificial joints and bone repair materials.

The application provides polybutene-1 and a preparation method thereof, a non-metallocene catalyst used in the preparation method and a preparation method of the non-metallocene catalyst, and the non-metallocene catalyst comprises the following formula I structure: wherein R1 and R2 are selected from hydrogen and a hydrocarbon group with 1-10 carbon atoms, R1 and R2 are the same or different, R3 is selected from hydrogen and a hydrocarbon group with 1-10 carbon atoms, R4 is selected from a methyl group, an ethyl group and a n-propyl group, and Ar is a phenyl group, a naphthyl group, a phenyl group substituted with an aliphatic hydrocarbon group or a naphthyl group substituted with an aliphatic hydrocarbon group. The non-metallocene catalyst of the application has a bridged pyridyl amine hafnium structure, is used for catalyzing synthesis of polybutene-1, has high catalytic activity, high monomer conversion rate, and the prepared polybutene-1 has high stereoregularity and narrow distribution.

This invention provides an MC-type carbide-reinforced Nb-based alloy spherical powder, its preparation method, and its application, belonging to the field of metal material preparation technology. The invention involves distributing the MC-type carbide-reinforced Nb-based alloy spherical powder according to its composition, followed by suspension induction melting and casting to obtain a master alloy ingot. The master alloy ingot is then machined to obtain an Nb-based alloy electrode rod. Using the Nb-based alloy electrode rod as raw material, powder is produced by plasma rotating electrode atomization to obtain the MC-type carbide-reinforced Nb-based alloy spherical powder. The MC-type carbide-reinforced Nb-based alloy spherical powder prepared by the method of this invention has uniform composition, controllable particle size with a narrow distribution range, good sphericity, low O and N content, and high purity, making it suitable for additive manufacturing.

The present application relates to a kind of glass microsphere fillers with coal gasification fine slag as raw material and its preparation method, method includes taking coal gasification fine slag dilution with water into 20-40 wt% coal gasification fine slag slurry, after sufficient stirring to slurry, through 300 mesh sieve, collect sieve under composite slurry, solid-liquid separation is carried out to material, filter cake is dried, then calcined at 700 DEG C and carbon is removed, obtain glass microsphere filler;The filler of the present application can be directly used in the preparation of plastic products without organic modification, play the role of reinforcing agent in the obtained plastic products, improve the strength, hardness, anti-aging, high temperature stability of product.

The invention discloses a temperature-sensitive wall fixing agent based on Pickering emulsion and a preparation method of the temperature-sensitive wall fixing agent, and relates to the cross technical field of exploration and development of carbonate oil and gas reservoirs and oilfield chemistry. The temperature-sensitive wall fixing agent is prepared from the following raw material components: a long side chain functional monomer, a temperature-resistant and salt-resistant functional monomer, an acrylamide monomer, a cationic functional monomer, a Pickering emulsifier, a stabilizer, an initiator, white oil and water. The temperature-sensitive wall fixing agent is prepared by preparing a reverse-phase water-in-oil emulsion by using a Pickering emulsifier, introducing a long-side-chain functional monomer, a temperature-resistant and salt-resistant functional monomer, an acrylamide monomer and a cationic functional monomer, and carrying out suspension polymerization by using the reverse-phase emulsion. The catalyst has the advantages of moderate molecular weight, narrow distribution range, excellent temperature resistance and compression resistance, strong rock adsorbability, timely temperature response and the like.

This invention relates to the field of biomedical technology and provides a method for preparing uracil-modified gold nanoconjugated materials and their applications. The method includes the following steps: in the presence of a reducing agent, a uracil ligand solution is slowly added to a gold precursor solution for a controlled reduction reaction to form gold nanoconjugated materials with an average particle size ≤2 nm; a thiolated uracil derivative is added to the dispersion of the obtained gold nanoconjugated materials, and the pH of the reaction system is adjusted to alkaline, so that the thiolated uracil derivative is bound to the surface of the gold nanoconjugated materials through Au-S bonds, thereby obtaining uracil-modified gold nanoconjugated materials. This material possesses ultra-small size, pH-responsive surface, and selective uptake characteristics by pathogens, enabling it to efficiently penetrate periodontal biofilms and achieve efficient clearance and virulence blocking against periodontal pathogens by interfering with bacterial proton kinetic potential and inhibiting the secretion of virulence factors.

The preparation method comprises the following steps: heating and stirring polyol, aliphatic isocyanate and an internal emulsification monomer in a nitrogen protection environment at a heating temperature of a first preset temperature to obtain a prepolymer, and when the content of isocyanate groups in the prepolymer reaches a preset content, adding the internal emulsification monomer into the prepolymer to obtain the waterborne polyurethane composite material. Cooling the prepolymer to a second preset temperature, wherein the first preset temperature is greater than the second preset temperature; adding organic amine into the cooled prepolymer, stirring to obtain a waterborne polyurethane emulsion, adding a cyclic carbonate monomer into the waterborne polyurethane emulsion, and stirring to obtain a mixed emulsion; stirring the ketiminated polyamine, the polyether amine and the functional filler at room temperature to obtain sol, mixing the mixed emulsion and the sol according to a preset molar ratio, and adding a functional aid to obtain the water-based poly-carbon composite material. The curing effect of the water-based poly-carbon composite material in a low-temperature and high-humidity environment is improved.