77 results about "Magnesium acetate" patented technology

The invention relates to the technical field of biological detection, and discloses a mycoplasma pneumoniae nucleic acid rapid detection method, which comprises the following steps: mixing a sample to be detected with a multifunctional pretreatment buffer solution containing tris (hydroxymethyl) aminomethane, potassium acetate, polyethylene glycol, saponin, spermine tetrahydrochloride and tris (2-carboxyethyl) phosphine hydrochloride, and carrying out cracking treatment; a cracking mixed solution is obtained; redissolving the enzymatic isothermal amplification basic reagent, the specific primer and the probe to obtain a redissolving amplification system; sucking the supernatant of the cracking mixed solution, adding the supernatant into a redissolving amplification system, and adding a magnesium acetate solution to obtain a reaction mixed solution to be detected; and carrying out isothermal amplification and signal acquisition to obtain a detection conclusion. The multifunctional pretreatment buffer solution is used for cracking the to-be-detected sample, sample liquefaction, cracking and nucleic acid release are completed in a single system, the nucleic acid extraction and purification step of centrifugal column adsorption or magnetic bead elution is avoided, and the operation process is simplified.

The invention relates to a liquid detergent composition comprising a first surfactant selected from fatty alcohol ether sulfates, a second surfactant selected from betaines, optionally at least one solvent selected from ethanol, propanol, isopropanol, ethylene glycol, butyl glycol, propylene glycol, polypropylene glycol, alcoholamine, monoethanolamine, glycerol and mixtures thereof, wherein the salt concentration in the composition is about 0.2 to about 10 wt.-% and wherein the salt is selected from the group consisting of sodium salts such as sodium chloride, sodium sulfate, sodium formate, sodium acetate or sodium propionate, potassium salts such as potassium chloride, potassium sulfate, potassium formate, potassium acetate or potassium propionate, magnesium salts such as magnesium chloride, magnesium sulfate, magnesium formate, magnesium acetate or magnesium propionate, and calcium salts such as calcium chloride, calcium sulfate, calcium formate, calcium acetate or calcium propionate, and mixtures thereof, and wherein the composition is a concentrate that can be diluted with water while maintaining or increasing the viscosity.The present invention further relates to the use of such a cleaning composition for cleaning hard surfaces, in particular dishes, and to a process for preparing a cleaning composition, the process comprising diluting the concentrated liquid cleaning composition with water.

The invention discloses an environment-friendly snow melting agent which is mainly prepared from the following raw materials in percentage by mass: 20-50% of potassium acetate, 10-16% of potassium chloride, 4-10% of calcium chloride and calcium acetate, 3-7% of magnesium chloride, 10-30% of an ice-resistant binder, 11-17% of a soil protective agent, 5-6% of cellulose and 3-9% of a plant protective agent. The ice-resistant binder is one or a combination of more of calcium acetate, magnesium acetate, potassium acetate and potassium formate, the mass ratio of calcium acetate to magnesium acetate is 3: (7.5-8.5), and the soil protective agent comprises 5-15% of diatomite and 10-20% of bentonite. Compared with the prior art, the environment-friendly snow melting agent disclosed by the invention can reduce the freezing point, prevent adhesion of an ice layer and a road surface and accelerate melting of an ice surface, so that a melted ice-snow-water mixture is easier to remove, effective recycling of resources is realized, pollution to the environment is reduced, and meanwhile, the treatment pressure of wastes is reduced.

The invention discloses a preparation method of bis-hydroxyethyl bisphenol A ether, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: adding bisphenol A, a mixed acetate catalyst and a solvent into a reaction kettle, starting stirring, replacing nitrogen, heating to a reaction temperature, starting to introduce ethylene oxide, keeping the temperature after the ethylene oxide is added, and continuously reacting until the pressure is not reduced any more to obtain bisphenol A; cooling to a desolventizing temperature, desolventizing until no solvent is discharged, cooling, degassing, and discharging to obtain the bis (hydroxyethyl) bisphenol A ether, wherein the mixed acetate catalyst is prepared from calcium acetate, magnesium acetate and barium acetate; the solvent is methyl cyclohexane. According to the preparation method, the specific mixed acetate is adopted as the catalyst, methyl cyclohexane is adopted as the solvent, the excellent catalytic effect is achieved, the prepared bis-hydroxyethyl bisphenol A ether is high in content, low in hydroxyl value and light in color, and the solvent is small in toxicity and easy to recycle.

The invention relates to a method for accurately controlling the acetyl substitution degree of cellulose acetate, which comprises the following steps: adding ground wood pulp into a reaction kettle, adding acetic acid, stirring at room temperature, then adding acetic acid, acetic anhydride and sulfuric acid, mixing, starting acetylation reaction, and gradually raising the system temperature in the reaction process. After reacting for a period of time, stretching a probe of an on-line infrared instrument into the reaction kettle to collect infrared spectrum data on line, adding a magnesium acetate solution, and starting hydrolysis reaction; adding part of the magnesium acetate solution and water after a period of time, maintaining for a period of time, adding part of the magnesium acetate solution after the relative esterification degree monitored by an online infrared instrument reaches a target value, and terminating the hydrolysis reaction; compared with the prior art, the hydrolysis reaction endpoint can be accurately identified on line, esterification degree fluctuation caused by inaccurate reaction time control is avoided, the production efficiency and economic benefits are improved, and the product quality is favorably improved.

The invention relates to the technical field of biological analysis and detection, and particularly discloses a streptococcus mutans detection kit based on an anchored CRISPR-Cas12a enhanced paper-based micro-fluidic chip and a detection method. The detection kit comprises an RAA solution or RAA freeze-dried powder, magnesium acetate or a magnesium acetate solution, TMB or a TMB solution, an RAA forward primer, an RAA reverse primer, a cell lysis buffer, a buffer system and a paper-based micro-fluidic chip. The detection method comprises the following steps: establishing a standard curve and detecting a sample. The detection kit is used for detecting the content of streptococcus mutans and has the characteristics of high efficiency, rapidness, specificity, sensitivity, portability and the like, and the method is simple and convenient to operate, low in detection cost and capable of being applied to on-site detection of streptococcus mutans.

The invention provides a preparation method of unsaturated fatty acid, which obviously reduces the residual amount of dioxin in grease through tromethamine treatment, effectively separates EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) through magnesium acetate precipitation, and improves the cycle use frequency of silver nitrate cycle use liquid through stannous chloride treatment and alkaline alumina treatment. And the unsaturated fatty acid separation capability of the silver nitrate recycling liquid is maintained.

The invention belongs to the technical field of biology, and particularly discloses a chicken semen cryopreservation solution and a preparation method thereof. The chicken semen cryopreservation liquid comprises a cryoprotection liquid I and a cryoprotection liquid II. The freezing protection liquid I is prepared from the following components: glucose, sodium glutamate, potassium acetate, dipotassium phosphate, magnesium acetate, N, N-bis (2-ethoxyl)-2-aminoethanesulfonic acid and an antibiotic solution. And the freezing protection liquid II comprises dimethylformamide and nano zinc oxide. The invention discloses a chicken semen cryopreservation solution and a preparation method thereof, by applying the chicken semen cryopreservation solution, the fertilization and incubation performance of frozen semen is remarkably improved, centrifugation-free and direct semen deposition of the frozen semen are realized, and physical damage and activity reduction caused by the centrifugation process to sperms are avoided.

The application provides a method for preparing calcium-magnesium acetate environment-friendly snow-melting corrosion inhibitor from chlor-alkali salt mud solid waste, and belongs to the technical field of comprehensive utilization of solid waste and organic material synthesis. Firstly, the chlor-alkali salt mud is prepared into slurry with water, then under the action of acidification aid and ionic liquid, the acetate is added at one time, and then the calcium-magnesium acetate environment-friendly snow-melting corrosion inhibitor is precipitated in the alcohol precipitation solution. The method can achieve 84.13-87.26% of the utilization rate of the salt mud, 95-99.99% and 85-92% of the extraction rates of Ca 2+ and Mg 2+ in the salt mud respectively, basically realizing the full recovery of high-value components in the salt mud. The precipitation rates of Ca 2+ and Mg 2+ in the solution are 96.4-99.9% and 96.6-99.9% respectively, basically realizing the full precipitation of Ca 2+ and Mg 2+ , the product yield reaches 96.5-99.9%, the whiteness of the product reaches more than 98.0, no waste liquid is generated in the whole process, and the recycling of the salt mud solid waste is realized.

An embodiment of the present invention discloses an oil removal material, a preparation method thereof and an application. The method includes: tetraethyl orthosilicate, iron acetate, and magnesium acetate are subjected to hydrolysis and condensation reactions in the presence of a solvent and hydrochloric acid to form a transparent sol, and the sol is subjected to vacuum freeze-drying and grinding treatments to obtain a powder; the powder, water, and cetyltrimethylammonium chloride are subjected to a hydrothermal reaction in a high-pressure reaction kettle to obtain a hydrothermal product; the hydrothermal product is subjected to centrifugal separation and washing, and then calcined at 500-600 °C to obtain the oil removal material. The material provided by the present invention has good thermal stability, a large specific surface area, a high adsorption capacity, can be regenerated and recycled multiple times, is particularly suitable for oil removal and purification of recovered ammonia water in the coal chemical industry, and has potential industrial application prospects.

The invention provides a method and system for continuously preparing trifluoroiodomethane, and the method comprises the following steps in the same reactor: S1, inputting trifluoromethane, iodine vapor and air into the reactor, and reacting under the action of a catalyst to prepare trifluoroiodomethane; s2, when the reduction amplitude of the reaction yield relative to the initial reaction yield reaches a set threshold value, stopping inputting trifluoromethane and iodine vapor into the reactor, and continuously introducing air to regenerate the catalyst; and S3, after the regeneration of the catalyst is completed, repeatedly executing the steps S1 to S2. The preparation process of the mesoporous carrier used by the catalyst comprises the following steps: dispersing nano SiO2 spheres in a magnesium acetate or aluminum acetate solution, then adding an NH4F solution, and reacting under a stirring condition to obtain a mesoporous carrier precursor; and treating the mesoporous carrier precursor by adopting a solution etching method. According to the method for continuously preparing trifluoroiodomethane, the service life of the catalyst is long, the technological process is simple and efficient, and the regeneration difficulty of the catalyst is reduced.

The invention discloses a method for preparing compact fine-grain magnesium aluminate spinel ceramic by low-temperature sintering, which comprises the following steps: S1, mixing ethanolamine, magnesium acetate tetrahydrate and water according to a certain proportion to obtain a mixed solution A; s2, mixing citric acid, aluminum isopropoxide and water according to a certain proportion to obtain a mixed solution B; s3, slowly adding the mixed solution A into the solution B in the step S2 to form uniform colloid; s4, drying the colloidal solution to obtain a dried precursor; s5, performing low-temperature calcination on the precursor to obtain nano magnesium aluminate spinel powder; s6, carrying out ball milling and spray granulation to obtain spherical granulation powder with uniform particle size; s7, performing dry pressing molding and cold isostatic pressing molding to obtain a to-be-sintered ceramic biscuit; and S8, sintering in a muffle furnace to obtain the final magnesium aluminate spinel ceramic. The powder is subjected to ball milling, spray granulation, dry pressing forming and cold isostatic pressing forming, and then the compact fine-grain magnesium aluminate spinel ceramic is prepared through low-temperature sintering.

This invention discloses a reaction tube for recombinase polymerase amplification (RPA), belonging to the field of nucleic acid detection. The reaction tube of this invention includes a tube body and a cap separate from the tube body. The tube body contains lyophilized bulbs or lyophilized powder containing premixed nucleic acid detection reagents, and the cap contains lyophilized powder containing an activator. The tube body and cap are sealed with a thin film. The lyophilized bulbs or lyophilized powder containing the premixed nucleic acid detection reagents include: recombinase, single-stranded DNA-binding protein, strand displacement DNA polymerase, buffer components, ATP, ATP regeneration components, and dNTPs. The lyophilized powder containing the activator includes: potassium ions, magnesium ions, and polyethylene glycol. This invention enables magnesium acetate to stably adhere to the cap, solving the problem of easy spillage of the lyophilized activator in the cap. In use, only the nucleic acid of the sample to be tested needs to be added; the operation is simple, easy to promote and apply, and suitable for batch detection.

The application belongs to the technical field of concrete admixtures, and provides a polycarboxylic high-performance water-reducing agent powder concentration process, in which a high-functionality polycarboxylic ether copolymer aqueous solution with polyoxyethylene side chains, carboxyl groups and sulfonic acid groups is prepared from polyethylene glycol methyl ether methacrylate, acrylic acid and 2-acrylamido-2-methylpropanesulfonic acid copolymerization, then magnesium acetate tetrahydrate is used for partial neutralization to form reversible magnesium carboxylate ion clusters, and the product is dehydrated, cooled into pieces and crushed and classified by a wiped-film evaporator or a falling-film evaporator to obtain a powder concentration product. The obtained product has a moisture content of 0.2-2.0 wt%, a glass transition temperature of 45-65 DEG C and a volume median particle size D50 of 60-150 mu m, and solves the problem that storage stability and redispersibility, processing fluidity and water-reducing performance are difficult to be considered in the powderization process, and is suitable for storage, transportation and application.

The invention belongs to the field of metal-organic framework (MOF) material synthesis, and discloses a method for preparing a UTSA-16 material through two-step ball milling and a product. The method comprises the following steps: putting citric acid and potassium hydroxide into a ball mill for ball milling; adding metal acetate into the ball mill, mixing the metal acetate with the obtained product, carrying out ball milling again, and then washing and drying the obtained product to obtain a UTSA-16 material; the metal acetate is zinc acetate or a combination of zinc acetate and one of cobalt acetate, magnesium acetate and copper acetate. According to the efficient and green method for preparing the high-quality UTSA-16 material, citric acid and potassium hydroxide are subjected to ball milling to prepare potassium citrate, then mechanical energy generated by ball milling is utilized again to promote the potassium citrate and metal acetate to be subjected to a coordination reaction, the ion concentration in the raw materials in the reaction process is higher, and the yield is higher. The method has the advantages of high synthesis efficiency, high yield and the like, and the preparation process has the advantages of mild reaction conditions, low energy consumption, greenness, high efficiency and the like.

The invention relates to the technical field of snow-melting agents, and particularly discloses an environment-friendly snow-melting and deicing composition and a preparation method thereof. The environment-friendly snow-melting and deicing composition comprises organic acid salt sustained-release microspheres, the organic acid salt sustained-release microsphere comprises a core material and a shell layer wrapping the core material, and according to the total weight of the organic acid salt sustained-release microsphere, the core material comprises the following raw materials in parts by weight: 30-45 parts of calcium magnesium acetate, 10-20 parts of sodium formate, 15-25 parts of potassium acetate, 8-15 parts of urea, 1-3 parts of a surfactant and 2-5 parts of a corrosion inhibitor; the shell layer is prepared from the following raw materials in parts by weight: 5 to 8 parts of sodium alginate, 3 to 6 parts of chitosan, 2 to 4 parts of calcium chloride, 1 to 3 parts of carboxymethyl cellulose and 1 to 2 parts of nano silicon dioxide. The snow melting and deicing speed of the environment-friendly snow melting and deicing composition in a severe cold environment can be increased.

This invention discloses a method for preparing a strontium titanate modified layer on the surface of zirconia based on an impregnation-heat treatment method, comprising: (1) mixing titanium sulfate, urea and water to obtain a precursor liquid A, placing zirconia ceramic in the precursor liquid A, heating to boiling and maintaining for a period of time, then removing the zirconia ceramic, and after heat treatment A, preparing a titanium dioxide film on the surface of zirconia; (2) mixing H2O2 aqueous solution, ammonia and deionized water, adding metatitanic acid and stirring to dissolve, obtaining a precursor liquid B, placing the zirconia with the titanium dioxide film in the precursor liquid B, and allowing it to stand and react for a period of time at room temperature, depositing zirconia modified with a titanium dioxide precursor layer; (3) dissolving strontium acetate, or a mixed salt composed of calcium acetate and / or magnesium acetate and strontium acetate in deionized water to obtain an impregnation treatment solution, placing the zirconia modified with the titanium dioxide precursor layer in the impregnation treatment solution, allowing it to stand and react for a period of time, and then removing it, and after heat treatment B, preparing a strontium titanate modified layer on the surface of zirconia. The strontium titanate layer prepared on the surface of zirconia ceramic in this invention is tightly attached to the zirconia substrate and has high hydrophilicity, which is conducive to the adhesion of proteins and cells in the human body. At the same time, it can release active factors such as strontium ions for a long time to promote bone formation and bone regeneration at the implantation site, ultimately enhancing the osseointegration capacity of the zirconia implant.

This invention relates to a method for preparing a nonlinear optical material and its application, specifically a magnesium aminodiacetate dihydrate compound. The molecular formula of the crystal is Mg[NH2(CH2COO)2]·2H2O. The Mg[NH2(CH2COO)2]·2H2O crystal does not have a center of symmetry, belongs to the tetragonal crystal system, has a space group of P-421c, and has cell parameters of α=β=γ=90°, Z=2. The nonlinear optical crystal of this invention has a large frequency doubling effect; at the same time, its ultraviolet absorption edge is 225nm, thus belonging to the tetragonal crystal system, with a space group of P-421c and cell parameters of α=β=γ=90°, Z=2. The nonlinear optical crystal can achieve the second harmonic of Nd:YAG (λ=1.064μm); and it can be predicted that the Mg[NH2(CH2COO)2]·2H2O crystal can be used in the third harmonic generator of Nd:YAG.

A method of producing magnesium cement. The method may comprise mixing water at a temperature of between approximately 50° C. and 100° C., a magnesium oxygen-containing compound and a magnesium salt. In some embodiments, the water is heated to a temperature of between approximately 70° C. and 90° C. The magnesium oxygen-containing compound may comprise one or more of magnesium oxide and magnesium hydroxide. The magnesium salt may comprise one or more of magnesium acetate, magnesium bromide, magnesium oxalate, magnesium thiosulfate, magnesium phosphate, magnesium nitrate, magnesium silicate, a magnesium chloride in any hydration state, anhydrous magnesium chloride, hexahydrate magnesium chloride, a magnesium sulfate in any hydration state, anhydrous magnesium sulfate, heptahydrate magnesium sulfate and magnesium carbonate.

The invention provides a medium element effervescent fertilizer capable of being mixed with a phosphorus and potassium fertilizer and containing calcium and magnesium elements and a preparation method of the medium element effervescent fertilizer, and belongs to the technical field of agricultural fertilizers. The effervescent fertilizer comprises a magnesium source, a calcium source, solid organic acid, a fertilizer compatible agent, an anti-caking agent, a disintegrating agent and an adsorbent, the magnesium source is selected from one of anhydrous magnesium sulfate and magnesium acetate tetrahydrate, the calcium source is selected from one of calcium formate and calcium carbonate, and the solid organic acid is selected from one of citric acid and malic acid; in percentage by mass, the content of magnesium in the effervescent fertilizer is 2-5%, the content of calcium is 5-10%, the total content of calcium and magnesium is 10-15%, and the content of the solid organic acid is 27-63%. The effervescent fertilizer can realize simultaneous supplement of calcium and magnesium for plants, has good solubility, can be used together with phosphorus and potassium fertilizers by being mixed with water, is stable in system, does not generate precipitates, and does not block pipelines and nozzles.

The application relates to a method for synthesizing 2,5-furan dicarboxylic acid from 5-hydroxymethylfurfural by using a ruthenium-loaded copper-cobalt metal oxide composite magnesium oxide catalyst. The method comprises the following steps: mixing and grinding a copper-cobalt hydroxide precursor prepared by a hydrothermal-calcination method with anhydrous magnesium acetate and then calcining to obtain a catalyst carrier; and using an impregnation-reduction method to load ruthenium nanoparticles on the carrier as an active component. The synergistic effect of the active component and the carrier enables 5-hydroxymethylfurfural to be catalytically converted into 2,5-furan dicarboxylic acid in a high-efficiency and selective manner. The catalyst preparation process is simple and easy to scale up. In the absence of alkali, the conversion rate of 5-hydroxymethylfurfural can reach 100%, and the yield of 2,5-furan dicarboxylic acid is 86.1%. The semi-preparative liquid chromatography is used for green separation and purification of the product, and 2,5-furan dicarboxylic acid with a purity of more than 99% is obtained. The method has potential application value for large-scale production of 2,5-furan dicarboxylic acid.

The application discloses a high-efficiency stable Lewis acid-containing heterogeneous catalyst and a preparation method and application thereof, and belongs to the technical field of cycloaddition reaction catalysts.The heterogeneous catalyst has strong nucleophilic groups and strong electrophilic groups.The Lewis acid-containing raw material is selected from one of zinc acetate, cobalt acetate, copper acetate, ferrous acetate, magnesium acetate, nickel acetate, calcium acetate, manganese acetate, lead acetate and tin acetate.The prepared Lewis acid-containing heterogeneous catalyst is applied to catalyzing the cycloaddition reaction of an epoxide and CO2, and the cycloaddition reaction of ethylene oxide (EO) / propylene oxide (PO) and CO2 is preferentially adopted.The problems of difficult separation of a homogeneous catalyst and insufficient activity of a heterogeneous catalyst are preferably solved.

A method of producing magnesium cement. The method may comprise mixing water at a temperature of between approximately 50° C. and 100° C. and a magnesium salt to form an intermediate mixture and then mixing the intermediate mixture with a magnesium oxygen-containing compound. The magnesium oxygen-containing compound may comprise one or more of magnesium oxide and magnesium hydroxide. The magnesium salt may comprise one or more of magnesium acetate, magnesium bromide, magnesium oxalate, magnesium thiosulfate, magnesium phosphate, magnesium nitrate, magnesium silicate, a magnesium chloride in any hydration state, anhydrous magnesium chloride, hexahydrate magnesium chloride, a magnesium sulfate in any hydration state, anhydrous magnesium sulfate, heptahydrate magnesium sulfate and magnesium carbonate.

The invention relates to the field of composite acetate, and discloses a slow-release composite acetate low-freezing-point filler and a preparation method thereof.The preparation method comprises the steps that any two or more of sodium acetate, calcium acetate, potassium acetate or magnesium acetate are selected according to a preset proportion and evenly mixed, and an acetate mixed material is obtained; any two or more than two carriers of lignin fiber, diatomite, bentonite, zeolite and attapulgite are selected according to target slow release performance requirements; deionized water is taken and placed in an oil bath stirring pot, the heating temperature is controlled to 60 DEG C, and the acetate mixture is added; slowly adding the composite carrier within 10 minutes after the acetate is completely dissolved; transferring the adsorbed slurry to a constant-temperature drying box, and drying at 120 DEG C for 68 hours; mechanically crushing the dried solid material, controlling the particle size at 0.06 mm, and performing ultrasonic screening to obtain an intermediate product with uniform particle size; the invention has the advantage of excellent slow release performance.

The present invention relates to a cell lysate wherein the lysis buffer comprises magnesium acetate, the phosphorylation inhibitor K3L, the agonist of dephosphorylation GADD34 and a caspase inhibitor for use in, or as, a cell-free system and a method for preparing a cell-free protein synthesis system. Further provided is a method for expressing a protein in the cell-free protein synthesis system, a method for screening for a candidate compound for an effect on a target molecule and a use of the cell-free protein synthesis system. The present invention also provides a kit for the above-mentioned cell-free systems.

The invention provides a micronucleus purification kit and a micronucleus purification method. The kit comprises cytochalasin B; a buffer solution I; the buffer solution I contains 1.8 M of sucrose, 10 mM of Tris-HCl, 5 mM of magnesium acetate and 0.1 mM of EDTA (Ethylene Diamine Tetraacetic Acid), and the pH (Potential of Hydrogen) of the buffer solution I is 8.0; a buffer solution II; the buffer solution II is specifically frozen PBS (Phosphate Buffer Solution) containing 0.3% of BSA (Bovine Serum Albumin), 0.1% of NP-40 and a protease inhibitor; a lysate; the lysis solution contains 10 mM of Tris-HCl, 2 mM of magnesium acetate, 3 mM of CaCl2, 0.32 M of cane sugar, 0.1 mM of EDTA (Ethylene Diamine Tetraacetic Acid) and a detergent, and the pH (Potential of Hydrogen) of the lysis solution is 8.5; a replenisher I; the kit comprises the following components in percentage by weight: 1mM of dithiothreitol, 0.3% of BSA (Bovine Serum Albumin), 0.15 mM of spermine, 0.75 mM of cane sugar and a protease inhibitor; a replenishing liquid II; the kit comprises the following components in percentage by weight: 1mM of dithiothreitol, 0.3% of BSA (Bovine Serum Albumin), 0.15 mM of spermine and 0.75 mM of spermidine; sucrose I; sucrose II; wherein the sucrose I and the sucrose II are different in weight so as to form a sucrose density gradient, reagents required by each step in the micronucleus purification process are provided, and the experimental steps are clear and definite, do not depend on an ultra-speed centrifuge, and are simple and convenient.

The invention discloses a magnesium modified wheat straw biochar-based slow-release rhizobium fertilizer and a preparation method thereof. The preparation method comprises the following steps: constructing hierarchical porous biochar MgWBC with magnesium-based active sites by adopting magnesium acetate impregnation and high-temperature pyrolysis; granular urea is used as a core, chitosan is used for packaging to realize directional loading and surface phase inversion film sealing of an MgWBC layer and rhizobium, and a composite structure with pH response capability is constructed. According to the method disclosed by the invention, the stress resistance and the directional colonization efficiency of the rhizobium are remarkably improved by utilizing the characteristic that the nitrogenase is activated by magnesium and the refuge effect of pores of the biochar. In a soybean-corn intercropping system, soybean nodulation and nitrogen fixation are enhanced and corn nutrition is met while nutrient slow release is realized through a synergistic mechanism of promoting nitrogen by magnesium. Experiments show that the yield of an intercropping system and the total nitrogen and effective magnesium level of soil can be remarkably improved, and the stability of soil aggregates is improved. The method is of great significance in promoting intercropping weight loss and efficiency improvement and cultivated land conservation.

This invention relates to the field of snow melting and de-icing technology, specifically to an environmentally friendly calcium-magnesium acetate composite snow melting agent and its preparation method, comprising the following raw materials: dolomite, biodegradable copolymer, nano-silica, and calcium carbonate. In this invention, the biodegradable copolymer, with its hydrophilic and hydrophobic segments in its molecular chain, can effectively regulate the crystal growth morphology and uniformly disperse within the system during the crystallization process. Subsequently, it synergistically works with nano-silica to form a composite coating network on the surface of calcium-magnesium acetate crystals, with the organic polymer as the continuous phase and nano-silica as the reinforcing phase. Simultaneously, the added calcium carbonate portion plays a role in inducing crystallization and regulating crystal morphology, while its micron-sized particles are embedded in the composite coating network as reinforcing fillers, jointly improving the physical properties of the product, including enhancing compressive strength, preventing storage agglomeration, and enabling the slow release of snow melting components, thus extending the effective action time.

The invention discloses a method for preparing dsRNA through large-scale in-vitro transcription based on a magnesium ion feeding strategy. The method comprises the following steps: S1, carrying out enzyme digestion on a plasmid by using EcoRI incision enzyme to obtain a target gene segment with T7 promoters at two ends; s2, performing in-vitro transcription in a transcription system by taking a target gene segment with T7 promoters at two ends as a template; s3, digesting the template to obtain a final product dsRNA; wherein linkage control of pH and Mg < 2 + > is carried out in the in-vitro transcription process in the step S2, the pH value of a transcription system is controlled to be 7.5-7.8 through alkali liquor, and the concentration of Mg < 2 + > in the transcription system is controlled to be 60-120 mM through fed-batch magnesium salt. The invention develops a novel large-scale in-vitro transcription method, magnesium acetate is supplemented in a material supplementing manner to improve the reaction yield, at least 20g of dsRNA can be obtained through one-time reaction, and the problem of low yield of an in-vitro transcription method is solved.

This invention discloses a method for preparing a copper-based catalyst, comprising the following steps: (1) placing the material into a processing tank and adding deionized water to the processing tank; (2) sealing the processing tank, introducing carbon dioxide and oxygen-containing gas into the processing tank, and heating and stirring the mixture in the processing tank; after the carbon dioxide in the processing tank is no longer consumed, cooling is started, and solid 1 is obtained after cooling to room temperature; (3) combining the solid 1 with a support to obtain solid 2; (4) drying and calcining the solid 2, then flaking, crushing, and reducing it to obtain a copper-based catalyst. The material in step (1) includes metallic copper, zinc, and magnesium acetate. Since this invention does not add nitrates and sodium salts, the production process does not generate NOx or leave sodium ions, thus effectively avoiding the problem of high preparation costs of copper-based catalysts due to the need for secondary treatment of NOx and sodium ions.