22 results about "Potassium cyanate" patented technology

The invention relates to the technical field of metal surface treatment, in particular to a method for improving the surface performance of a metal part through salt bath composite nitriding treatment, and particularly relates to a salt bath composite nitriding treatment process for a high-wear-resistance and high-fatigue shaft pin. Comprising the following steps: 1) pretreatment: carrying out sand blasting cleaning on the shaft pin and polishing until Ra is less than or equal to 0.8 mu m; 2) salt bath composite nitriding treatment: immersing the shaft pin into a salt bath containing sodium cyanate, potassium cyanate, sodium carbonate, lithium carbonate and an additive, and keeping the temperature at 560 DEG C for 2-4 hours; and (3) cooling and strengthening treatment: slowly cooling after dynamically cooling to 500 DEG C, and releasing residual stress in combination with oxidation treatment and low-temperature tempering. According to the process, a compact nitriding layer and a micro-boronizing layer are formed through the synergistic effect of rare earth oxide and fluoride, so that the surface hardness of the shaft pin reaches HV800-1100, the depth of the nitriding layer is 0.1-0.3 mm, the wear resistance is remarkably improved, the fatigue life is remarkably prolonged, the corrosion resistance is remarkably improved, and the process is suitable for surface strengthening of high-load mechanical parts.

The co-production and recovery process comprises the following steps: dissolving alpha-aminobutyric acid and potassium cyanate in water, and carrying out heating reaction to obtain an intermediate water solution; directly dropwise adding hydrochloric acid into the intermediate water solution, heating for reaction, cooling and filtering to obtain a main product filter cake and mother liquor; and drying the obtained main product filter cake to obtain the 5-ethyl hydantoin. Adding potassium hydroxide into the mother liquor to adjust the pH value, carrying out reduced pressure distillation until no distillate exists, adding ethanol, heating and filtering to obtain a potassium chloride filter cake and ethanol filtrate; concentrating and drying the ethanol filtrate, and recovering to obtain 5-ethyl hydantoin; washing the potassium chloride filter cake with ice water; drying the washed potassium chloride filter cake to obtain potassium chloride; and concentrating and drying the washing water after washing the potassium chloride filter cake to obtain the potassium chloride / ammonium chloride composite salt. According to the method, the product yield is increased, the waste liquid amount is reduced, and the production cost is further reduced, so that the method is very suitable for industrial large-scale environment-friendly production.

The present invention discloses a cyanase mutant, nucleic acid, recombinant expression vector and their applications, belonging to the field of bioengineering. The cyanase gene derived from Escherichia coli E. coli K-12 substr. MG1655 was subjected to site-directed mutagenesis, so that the encoded amino acid sequence was mutated from glycine G to alanine A at the 37th position, from lysine K to arginine R at the 154th position, and from glutamine Q to histidine H at the 51st position. The specific activity of the cyanase mutant G37A / K154R / Q51H of the present invention against potassium cyanate is 2.4 times that before mutation, and the half-lives at 30 °C and 40 °C are increased by 2.1 times and 2.6 times respectively. The cyanase parent of the present invention cannot catalyze potassium cyanide, while the specific activity of the mutant G37A / K154R / Q51H against potassium cyanide reaches 5.5 U / mg, and the half-lives at 30 °C and 40 °C are 2.5 h and 3.0 h respectively. The cyanase mutant of the present invention can efficiently catalyze the decomposition of the substrates potassium cyanate and potassium cyanide, so as to achieve the purpose of degrading cyanide-containing wastewater, and can be widely applied to industries such as chemical engineering, pharmaceuticals and metallurgy, and has broad application prospects.

This invention relates to a method for preparing cobalt selenide rich in double defects and its application in the electrocatalytic reduction of oxygen to hydrogen peroxide. First, selenium powder is mixed with sodium hydroxide solution to obtain material A. Cobalt salt is mixed with EDTA-2Na solution to obtain material B. Material B and material A are then mixed and subjected to a hydrothermal reaction. The resulting product is centrifuged, washed, and vacuum dried to obtain cobalt selenide powder. The cobalt selenide powder is dispersed in anhydrous ethanol, and then potassium thiocyanate powder is added. After vigorous stirring, ultrasonic exfoliation is performed. The product is centrifuged, washed, dried, and calcined to obtain cobalt selenide rich in double defects. This invention provides a simple preparation method that can rapidly and cost-effectively prepare double-defect cobalt selenide under mild conditions. The obtained double-defect cobalt selenide can effectively reduce oxygen to hydrogen peroxide under electrocatalytic conditions, solving the problems of high price and low efficiency of current catalysts for hydrogen peroxide production under acidic conditions.

The present invention relates to the field of metal surface treatment technology, in particular to a method for improving the surface performance of metal parts by salt bath composite nitriding treatment, specifically a salt bath composite nitriding treatment process for a high wear-resistant and high fatigue shaft pin. The process includes the following steps: 1) pretreatment: sandblasting and polishing the shaft pin to Ra≤0.8μm; 2) salt bath composite nitriding treatment: immersing the shaft pin in a salt bath containing sodium cyanate, potassium cyanate, sodium carbonate, lithium carbonate and additives, and keeping it at 560°C for 2-4 hours; 3) cooling and strengthening treatment: slowly cooling after dynamic cooling to 500°C, combining oxidation treatment and low-temperature tempering to release residual stress. The process forms a dense nitriding layer and a micro-boronization layer through the synergistic effect of rare earth oxides and fluorides, so that the surface hardness of the shaft pin reaches HV800-1100, and the depth of the nitriding layer is 0.1-0.3mm, which significantly improves wear resistance, fatigue life and corrosion resistance, and is suitable for surface strengthening of high-load mechanical parts.

The invention relates to the technical field of silane modified polyether resin, and particularly discloses a high-activity moisture-curing organosilicon-containing polymer component and a preparation process thereof. The preparation process comprises the following steps: S1, treating polyether polyol for 1-3 hours at the temperature of 100-120 DEG C, cooling to 30-50 DEG C, adding organic polyisocyanate, and stirring and reacting for 2-4 hours at the temperature of 40-80 DEG C to obtain a hydroxyl-terminated prepolymer; s2, adding a moisture-curing silane end-capping agent, and reacting for 2-4 hours at 40-60 DEG C under the protection of an inert atmosphere to obtain the high-activity moisture-curing polymer component containing the organic silicon, the preparation method of the moisture-curing silane end-capping reagent comprises the following steps: uniformly mixing chloromethyl triethoxy silane, potassium cyanate, ethanol, DMF and octadecyl crown ether, heating to 120-125 DEG C, reacting for 11-12 hours, filtering, and rectifying to obtain a fraction, namely the moisture-curing silane end-capping reagent.

The invention discloses a method for detecting the content of molybdenum in a cobalt-based alloy. The method comprises the following steps: obtaining a mass m sample of a cobalt-based alloy sample; the method comprises the following steps: thermally dissolving a sample with nitric acid and hydrofluoric acid until the volume is constant to a V sample, respectively adding a molybdenum test mixed solution and a potassium cyanate-thiourea mixed solution into an obtained sample solution, a sodium hydroxide aqueous solution serving as a blank solution and a molybdenum standard solution serving as a blank solution, and carrying out a chromogenic reaction; the absorbance of the sample solution, the blank solution and the molybdenum standard solution after color development is measured, the molybdenum content in the sample is calculated through the obtained absorbance, a V sample, an m sample and the like, and the molybdenum test mixed solution comprises oxalic acid, copper sulfate and sulfuric acid. According to the method, high-precision, high-stability and wide-content-range molybdenum content measurement can be realized through simple equipment.

The invention belongs to the technical field of transition metal coordination chemistry, and discloses a selenium cyanide coordinated cobalt single-ion magnet and a preparation method and application thereof, and the molecular formula of the selenium cyanide coordinated cobalt single-ion magnet is Co (bim) 4 (SeCN) 2. The preparation method of Co (bim) 4 (SeCN) 2 comprises the following steps: dissolving anhydrous cobalt chloride in absolute ethyl alcohol, adding potassium selenide, stirring, adding bim, fully reacting, and filtering to obtain a bluish violet solution; and placing the solution in a diethyl ether atmosphere, and standing for several days to obtain the cobalt single-ion magnet Co (bim) 4 (SeCN) 2. The preparation process is safe and simple, high in controllability and good in repeatability, and the prepared complex is good in stability and relatively high in purity and yield, has the property of a field-induced single-molecule magnet, and can be used as a molecule-based magnetic material to be applied to the fields of novel high-density information storage equipment and the like.

The application discloses a copper plating composition and a chemical copper plating process, and relates to the field of copper plating compositions, which is composed of the following components: a copper salt providing divalent copper ions; a complexing agent for complexing the divalent copper ions; a stabilizer for stabilizing the copper plating composition, which is selected from at least one of the group consisting of 2,2'-dipyridyl, potassium selenocyanate, potassium thiocyanate and 2-mercaptobenzimidazole; a reducing agent for reducing the complexed divalent copper ions to metallic copper; an alkaline adjusting agent for adjusting the pH value of the composition to an alkaline range suitable for chemical copper plating; and a solvent. The process stability and product yield are improved: through the optimized combination of the core stabilizer, the complexing agent and the reducing agent, the self-decomposition of the copper plating bath is effectively inhibited, the process stability is significantly enhanced, the incidence of key defects such as backlight defects in the metalization of the circuit board hole is greatly reduced, and the high yield of the final product is ensured.

The present invention discloses a gun-black tin-nickel alloy electroplating and electrolytic protection process. The electroplating process comprises: 240-280 g / L potassium pyrophosphate, 50-60 g / L nickel chloride hexahydrate, 7-9 g / L stannous chloride dihydrate, 1-2 g / L lanthanum chloride or praseodymium chloride, 13-18 g / L potassium thiocyanate, 0.6-1.8 g / L methionine, 20-30 g / L ammonium citrate, 4-6 g / L disodium ethylenediaminetetraacetic acid, a pH range of 7.8-8.2, a plating bath temperature of 35-40°C, a cathode current density of 1-3 A / dm2, and a cathode travel of 3-5 m / min. The electrolytic protection process is as follows: 2-5 g / L cerium chloride, 2-5 g / L sodium molybdate, 15-30 g / L sodium hydroxyethylidene diphosphonate, 100-150 g / L anhydrous potassium carbonate, pH range 11-13, room temperature operation, cathode current density 0.5-1.2 A / dm², using the plated part as the cathode and the titanium plate as the anode, and electrolysis for 60-120 seconds. The prepared gunmetal black tin-nickel alloy plated part was subjected to a neutral salt spray test for 96 hours in accordance with GB / T 10125-2021 "Artificial Atmosphere Corrosion Test Salt Spray Test", and no corrosive products were generated on the surface of the coating. The gunmetal black tin-nickel alloy electroplating and electrolysis process of the present invention improves the corrosion resistance of the coating and solves the high pollution problem of the dichromate electrolytic protection method.

The invention relates to the technical field of compound preparation, in particular to a preparation method of 2, 4-dichlorothieno [3, 2, d] pyrimidine, which comprises the following steps: S1, adding methyl 3-aminothiophene-2-formate, water and glacial acetic acid into a reaction kettle, dropwise adding a potassium cyanate aqueous solution while stirring, and after dropwise adding, carrying out heat preservation reaction to obtain an intermediate I; s2, returning the intermediate I to a reaction kettle, adding water and a 30% sodium hydroxide solution for reaction, acidifying, and performing suction filtration to obtain an intermediate II; s3, dichloromethane, the intermediate II, a bismuth-based catalyst and diisopropylethylamine are added into the reaction kettle, phosphorus oxychloride is dropwise added for a reaction, after the reaction is quenched, aftertreatment is conducted, and a target product is obtained. The 2, 4-dichlorothieno [3, 2, d] pyrimidine prepared by the method has higher purity and yield, the reaction controllability is enhanced by controlling the reaction temperature, the dropping speed and the reaction time, and the safety risk caused by too violent reaction or out-of-control reaction is reduced.

The invention relates to the technical field of organic synthesis, in particular to a method for electrochemical synthesis of a 3-selenium cyano indolizine compound and application of the 3-selenium cyano indolizine compound. According to the method for electrochemical synthesis of the 3-selenium cyano indolizine compound, an indolizine compound, potassium selenide and an electrolyte are added into a solvent to form a reaction system, a graphite felt serves as an anode, a platinum sheet serves as a cathode, a constant-current reaction is conducted at the room temperature in the air atmosphere, the adopted current is 7 mA, and after the reaction is completed, the 3-selenium cyano indolizine compound is obtained. Carrying out post-treatment on the reactant to obtain a compound; the molar ratio of the indolizine compound to the potassium selenide cyanate is 1: (2-3), and the molar concentration of the electrolyte is 0.05 mol / L. The method has the advantages of wide substrate range, simple post-treatment and the like, and a new synthesis route and method are developed for the 3-selenium cyano indolizine compound. The obtained 3-selenium cyano indolizine compound shows remarkable anti-atherosclerosis activity and has the potential of being developed into an anti-atherosclerosis medicine.

The application discloses a detection structure capable of quickly identifying ferroferric oxide, and a preparation method and application thereof. The detection structure comprises a base body, and potassium ferricyanide and ammonium thiocyanate which are respectively adsorbed on opposite ends of the base body. The detection structure can quickly identify whether the ferroferric oxide is contained in a to-be-detected substance. The detection structure has low detection limit, high accuracy and simple operation.

This invention discloses a method for preparing flake potassium cyanate. Urea and potassium borohydride are ground in an agate mortar at a mass ratio of 1:0.10–0.12 for 30–60 minutes to obtain a first substance. The first substance is then spread evenly in a covered crucible and placed in the center of a muffle furnace. A solid-state melting method is used to ensure a complete reaction. The muffle furnace is heated from room temperature at a rate of 3–5 °C per minute. ‑1 The mixture was heated at a rapid rate until it reached 500–600°C, and held for 120 minutes to obtain a second substance. After the reaction was complete, the second substance was allowed to cool naturally, then washed with anhydrous ethanol, centrifuged, dried, and cooled to room temperature to obtain flake potassium cyanate. This invention proposes a novel method for preparing flake potassium cyanate using a solid-state melting method. The process for preparing flake potassium cyanate is simple, completed in one step, and has good application prospects.

The invention discloses a wide-band-gap perovskite thin film based on a potassium cyanate additive and a preparation method and application thereof, and relates to the technical field of solar cells. The preparation method sequentially comprises the following steps: coating a glass substrate / 4PADCB with a broad-band gap mixed perovskite precursor solution, doping the precursor solution with KOCN, dropwise adding an anti-solvent diethyl carbonate in the coating process, then annealing, and coating with a 1, 3-diaminopropane dihydriodate post-treatment solution to prepare the broad-band gap perovskite thin film based on the potassium cyanate additive. The doping of KOCN can improve the quality of the wide-band-gap perovskite thin film, reduce the defect state density of the thin film, prolong the service life of current carriers, and finally improve the photoelectric conversion efficiency of the cell. According to the invention, the problems of poor photoelectric conversion efficiency and stability of the broadband gap perovskite solar cell in the prior art are solved.

The invention relates to the technical field of reservoir transformation, in particular to a hydrogen bond inhibitor for fracturing and capable of reducing adsorption of high-molecular compounds and a preparation method thereof.The hydrogen bond inhibitor for fracturing is obtained according to the following method that potassium cyanate, ammonium chloride and heterocyclic methylamine with the required amount are mixed to obtain a mixture, a solvent with the required amount is added into the mixture to obtain mixed liquid, and the mixed liquid is stirred to be uniform; and heating the mixed solution, continuously refluxing, and irradiating the refluxed mixed solution with an ultraviolet lamp to react, thereby obtaining the hydrogen bond inhibitor for fracturing capable of reducing the adsorption of the high-molecular compound. The preparation and synthesis process is simple, the cost is low, on one hand, the obtained hydrogen bond inhibitor for fracturing capable of reducing adsorption of the high-molecular compound can greatly reduce the adsorption amount of fracturing fluid residues on the rock wall surface, the adsorption amount is reduced by 30% or above, and the yield of a single well after fracturing can be increased; and on the other hand, the obtained hydrogen bond inhibitor for fracturing capable of reducing adsorption of the high-molecular compound does not need to be purified and can be directly applied, so that the production cost is reduced.

The application discloses a method for improving electrochemical carbon dioxide reduction to produce methane under acidic conditions of a copper-based catalyst by using potassium thiocyanate. The method adds potassium thiocyanate into an electrolyte for electrochemical carbon dioxide reduction under acidic conditions of a copper-based catalyst, or simultaneously adds a potassium ion-containing salt and a thiocyanate ion-containing salt, and the existing potassium thiocyanate salt in the electrolyte can effectively regulate the electronic structure of a Cu surface, promote deep hydrogenation of an intermediate in a carbon dioxide reduction reaction, thereby improving the selectivity of methane synthesis, and meeting the needs of industrialized carbon dioxide electro-reduction to produce methane.

This invention relates to a method for preparing and applying a cobalt-deficient cobalt selenide-anchored high-loading Pt single-atom catalyst. Selenium powder is mixed with sodium hydroxide solution to obtain material A. Cobalt salt is mixed with EDTA-2Na solution to obtain material B. Material B and material A are mixed and subjected to a hydrothermal reaction. The resulting product is centrifuged, dried, and dispersed in anhydrous ethanol. Potassium thiocyanate powder is then added, and the mixture is ultrasonically exfoliated, centrifuged, washed, dried, and calcined to obtain Co-deficient cobalt selenide. This cobalt selenide is uniformly dispersed in an ammonium hydroxide aqueous solution. Under alkaline conditions, an ammonia solution containing tetraammineplatinum nitrate is added, and the reaction is carried out at room temperature for 24 hours. After centrifugation, washing, drying, and calcination, the desired product is obtained. This invention provides a simple preparation method that enables rapid and low-cost preparation of Co-deficient cobalt selenide under mild conditions. The Co-deficient cobalt selenide can anchor high-loading Pt single atoms, improving the stability of the Pt single atoms and thus enhancing the catalytic activity and selectivity of the catalyst for oxygen reduction to H₂O₂.

The present invention relates to the technical field of silane-modified polyether resins, and specifically discloses a highly active moisture-curing organosilicon polymer component and its preparation process; the preparation process includes the following steps: S1: Treat polyether polyol at a temperature of 100-120 °C for 1-3 h, cool down to 30-50 °C, add organic polyisocyanate, and stir and react at 40-80 °C for 2-4 h to obtain a hydroxyl-terminated prepolymer; S2: Add a moisture-curing silane-terminated agent and react at 40-60 °C for 2-4 h under the protection of an inert atmosphere to obtain the highly active moisture-curing organosilicon polymer component; the preparation of the moisture-curing silane-terminated agent includes the following steps: Mix chloromethyltriethoxysilane, potassium cyanate, ethanol, DMF, and 18-crown-ether evenly, heat up to 120-125 °C and react for 11-12 h, filter, and the distillate after rectification is the moisture-curing silane-terminated agent.

The present invention provides a method for detecting local selective corrosion of stainless steel, and belongs to the technical field of material corrosion resistance evaluation. The present invention immerses stainless steel in an electrolyte, selects a suitable electrolyte formula, wherein sulfuric acid and hydrochloric acid are used to dissolve metal grain boundaries, which is beneficial to subsequent electrochemical testing, uses potassium thiocyanate as a depolarizing agent for electrochemical testing, and selects a suitable scanning rate to obtain a corrosion characterization parameter I G , and then combined with the microscopic morphology of stainless steel, multiple stainless steel samples can be distinguished, thereby accurately and quantitatively evaluating the degree of local selective corrosion. The experimental results show that the detection method provided by the present invention can detect the four samples I G The value distinction is large and the morphology is different, which can be used to describe the degree of local selective corrosion.

The invention discloses a method for determining the total iron concentration in a citric acid-EDTA decontaminant of a pressurized water reactor nuclear power plant, which comprises the following steps of: adding ammonium persulfate into the decontaminant for determining the concentration of citric acid and EDTA under an acidic condition to completely oxidize and convert Fe < 2 + > in a solution into Fe < 3 + >, adding a potassium thiocyanate-sulfosalicylic acid color developing agent, and measuring the total iron concentration of the citric acid-EDTA decontaminant. Judging the molar concentration ratio of EDTA (Ethylene Diamine Tetraacetic Acid) to Fe < 3 + > in the cleaning solution according to the color of the solution, when the solution is purple or dark red, titrating the test sample by adopting an EDTA standard solution, calculating to obtain the Fe < 3 + > concentration, and adding the Fe < 3 + > concentration and the theoretical iron concentration corresponding to EDTA in the cleaning solution to obtain the total iron concentration under the condition; and when the solution is colorless or faint yellow, determining the concentration of free EDTA in the test sample by adopting an Fe standard solution, then obtaining the molar concentration of EDTA consumed by Fe < 3 + >, and correspondingly obtaining the total iron concentration. The determination method is simple and rapid to operate and high in accuracy, and can meet the total iron concentration test requirements of the citric acid-EDTA decontaminant in the pressurized water reactor nuclear power plant primary loop equipment chemical decontamination process.

The invention relates to the technical field of copper deposition compositions, in particular to a copper deposition composition and a chemical copper deposition process, and the copper deposition composition at least comprises a copper ion source, a complexing agent, a stabilizing agent, a reducing agent, an alkaline regulator and a solvent; wherein the stabilizing agent is selected from at least one of 2-2 bipyridine, potassium selenide, potassium thiocyanate or 2-mercapto benzimidazole, the problems that a copper deposition tank in the market is unstable and poor backlight is easily caused are effectively solved by optimizing selective matching and additive amount control of the complexing agent, the stabilizing agent and the reducing agent in the copper deposition composition, and the system is simple in component, low in cost and easy to popularize. And large-scale industrial popularization and application are easy to realize.