138 results about "Trimethyloxamine" patented technology

This invention discloses a method for preparing a high-temperature resistant, strongly basic anion exchange resin, belonging to the field of ion exchange resins. The method includes three steps: First, white spheres with a crosslinking degree of 6-10 undergo a chloromethylation reaction by sequentially adding zinc dichloride and tin tetrachloride to improve the uniformity of the chloromethyl group distribution in the chlorospheres; second, the chlorospheres undergo an etherification reaction using tetrabutylammonium bromide as a phase transfer catalyst, and the dropping rate of sodium methoxide solution is controlled to improve the etherification conversion rate; finally, the etherification product undergoes a quaternization reaction with a trimethylamine aqueous solution to obtain the strongly basic anion exchange resin. This invention, by selecting the degree of crosslinking and optimizing the catalyst addition method for chloromethylation and the sodium methoxide dropping rate for the etherification reaction, results in a more uniform distribution of quaternary ammonium groups in the resin, significantly improving the ion exchange capacity and high-temperature resistance of the resin.

The invention provides an aqueous zinc ion battery electrolyte, a preparation method thereof and a zinc ion battery, and belongs to the technical field of aqueous zinc ion batteries. The aqueous zinc ion battery electrolyte comprises an additive, an inorganic zinc salt and a solvent, the additive comprises at least one of trimethylamine substituted by 1-3 substituent groups, benzene and C3-C10 straight-chain alkane, and the substituent groups comprise phosphonic acid groups or phosphinic acid groups; the solvent comprises a sodium chloride aqueous solution. By adopting the additive with a specific structure and the solvent containing the sodium chloride aqueous solution, the cycle performance of the zinc negative electrode in the water-based zinc ion battery can be remarkably improved, and the service life of the water-based zinc ion battery is prolonged.

Disclosed is a method of synthesizing a compound selected from the group consisting of C-alkyl glycosides, C-alkenyl glycosides, C-heteroaryl glycosides, Se-glycosides and S-glycosides, the method comprising: a. Reacting a natural unprotected sugar with a 2-chloro-1, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3 The method comprises the following steps: reacting 1, 3-dimethylimidazoline chloride (DMC) and a mixture of heteroaryl mercaptan and trimethylamine (Et3N) in a mixture of water and dialkane to generate heteroaryl glycosyl thioether; b, under the irradiation of a blue light LED, in the presence of Hantzsch ester (HE), 1, 4-diazabicyclo [2.2. 2] octane (DABCO) and DMSO, heteroaryl glycosyl thioether and a reagent are subjected to light-induced cross coupling, and the compound is generated.

The invention relates to a silicon carbide-boron nitride three-dimensional heat conduction framework material and a preparation method and application thereof.The preparation method comprises the steps that boron nitride nanosheets are prepared into dispersion liquid, the pH of the dispersion liquid is adjusted through ammonia, then an organic silicon source is added for a reaction, and a precursor is obtained; the precursor comprises a boron nitride nanosheet and SiO2 nanoparticles loaded on the surface of the boron nitride nanosheet; mixing the precursor, polyamide acid and trimethylamine in a solvent, and performing freeze drying treatment to obtain composite aerogel; and sequentially carrying out thermal imidization treatment, carbonization treatment and carbon thermal reduction reaction on the composite aerogel to obtain the silicon carbide-boron nitride three-dimensional heat-conducting framework material. According to the preparation method, SiC nanowires are efficiently connected with BNNS to form a microstructure welded continuous heat-conducting network, and the prepared silicon carbide-boron nitride three-dimensional heat-conducting framework material has excellent heat conductivity, electric insulativity and flexibility when being used as a thermal interface material and is wide in application prospect.

The invention discloses a polyaluminum chloride-based flocculant as well as a preparation method and application thereof, belongs to the technical field of preparation of flocculants, and aims at solving the technical problem that the flocculation performance and the stability of a flocculant in the prior art need to be further improved. The surface charges of iron-based particles are adjusted through sodium citrate, so that the problem of particle agglomeration is effectively avoided, the coating uniformity of microgel is improved, and the specific surface area of the material is increased; abundant cation sites are introduced into the trimethylamine modified chitosan, so that the electrostatic adsorption capacity of the microgel on anion pollutants is remarkably enhanced, and meanwhile, the electrical property and the stability of a system are improved; the addition of sodium metasilicate further promotes the modified PAC to form a stable Al-O-Si bridging structure, the material is endowed with good three-dimensional skeleton strength and composite interface stability, the three components cooperate with each other and play key roles in particle dispersity, charge construction and skeleton stability, and finally, an efficient, stable and storable composite flocculation system is constructed.

The invention relates to the technical field of organic chemical synthesis, and discloses a continuous production process of a cationic etherifying agent, which comprises the following steps: taking trimethylamine hydrochloride and epoxy chloropropane as raw materials; the method comprises the following six steps: raw material pretreatment, premixing, continuous reaction, continuous separation, refining and product storage: mixing and dissolving trimethylamine hydrochloride and a solvent, preparing a catalyst solution, uniformly mixing the three materials through a static mixer, feeding into a multi-stage tubular reactor, and carrying out segmented temperature control continuous reaction, and performing flash evaporation solvent removal and rectification on the reaction product to obtain a crude product, and performing ion exchange impurity removal and reduced pressure distillation refining to finally obtain a high-purity product. The method solves the problems of low yield and more byproducts in the traditional process, and is suitable for industrial large-scale production.

The invention relates to a method for producing methylamine by a generally exothermic gas-phase reaction of methanol and ammonia as reactants in the presence of a heterogeneous catalyst at a pressure in the range of 15 to 35 bar. The reactants are evaporated in one or more heat exchangers and superheated prior to being fed to the reactor, wherein the heat exchangers in turn are heated with a stream of hotter product gas from the reactor. In addition to methylamine (monomethylamine, dimethylamine, and trimethylamine), the product gas stream contains unconverted reactants, water, and any other reaction by-products. To control the reactor inlet temperature and limit it to a temperature in the range of 350 DEG C to 410 DEG C, a suitable quenching liquid is introduced into the hot product gas stream prior to feeding the hot product gas stream to a heat exchanger for heating the reactants. Evaporation and overheating of the added quenching liquid removes the corresponding amount of energy extracted from the hot product gas stream, with the result of efficient and rapid cooling of the hot product gas stream. As a result, the temperature difference between the cold side and the hot side of the heat exchanger is small, which means less energy is transferred to the reactant stream, and thus its reactor inlet temperature can be adjusted or limited.

The invention discloses a mitochondrial / lysosome dual-targeting viscosity response AIE probe as well as a preparation method and application thereof. According to the probe, tetraphenylethylene (TPE) is used as an AIE light-emitting framework, and two flexible side chains containing hydrophilic units are introduced by utilizing the excellent structural modifiability of the TPE. The tail end of each side chain is modified with a trimethylamine group, quaternary ammonium salt cations derived from the trimethylamine group have localized positive charges, and combination with water molecules can be enhanced through ion-dipole interaction, so that the water solubility and biocompatibility of the molecules are effectively improved. Based on the design, the invention provides the AIE polymer probe which is constructed by taking TPE as a core and taking an amphiphilic flexible chain as a functional unit. The probe can establish a three-dimensional linear relationship among drug action time-regional viscosity-fluorescence lifetime (t-eta-tau) by capturing fluorescence lifetime signals inside and outside cells, so as to realize visual detection and quantitative analysis of average viscosity change of mitochondria and lysosome in the mitochondrial autophagy process.

The invention relates to a method for preparing an imine covalent organic framework gas sensor at normal temperature by virtue of a catalyst. A device involved in the method is composed of three sensors, a ceramic substrate and six electrodes. The recognition effect on trimethylamine, ethidene diamine and ammonia gas can be realized at room temperature (25 DEG C). The preparation method of the sensor array is simple, the sensor array has the advantage of performing non-contact identification detection at room temperature, and the practicability of the sensor is greatly enhanced. In addition, it is also found that preparation of a covalent organic framework by means of a catalyst at normal temperature and application of the covalent organic framework to gas-sensitive sensing detection are very promising means.

The invention belongs to the technical field of preparation of tetraisopropyl alcohol-based ethylenediamine, and particularly relates to a catalyst for preparing tetraisopropyl alcohol-based ethylenediamine as well as a preparation method and application of the catalyst. The catalyst is formed by chelating two amine nitrogen atoms with aluminum ions by taking an Al < 3 + > center as tetra-coordination and 1, 1-dimethoxytrimethylamine as a ligand, and has a structure as shown in a formula I in the specification. The two-component composite catalyst is formed on the basis of coordination and chelation of the organic metal compound and the organic amine, the organic metal compound can promote the antistatic performance of the tetraisopropyl alcohol ethylenediamine, and the organic amine can promote the compatibility of the tetraisopropyl alcohol ethylenediamine and a high polymer material, so that the antistatic property of the tetraisopropyl alcohol ethylenediamine is improved. Compared with a pure organic amine catalyst, the composite catalyst has the advantages of high reaction activity, side reaction inhibition, improvement of the conversion rate and selectivity of tetraisopropanolethylenediamine, no need of separation from the product, promotion of the product, reduction of the impurity separation problem in the subsequent process, reduction of the reaction pressure, low equipment requirement and reduction of the equipment investment.

The invention relates to a method for green, mild and efficient synthesis of methylamine hydrochloride based on photocatalysis. According to the method, methanol and ammonium chloride which are wide in source and low in price are used as raw materials, under the anaerobic condition, a Pd / TiO2 photocatalyst is adopted for a photocatalytic reaction, and target methylamine hydrochloride products including monomethylamine hydrochloride, dimethylamine hydrochloride and trimethylamine hydrochloride are synthesized in one step. Compared with traditional industrial synthesis, the photocatalysis technology has the advantages of mild reaction conditions, simplicity and convenience in operation, environmental friendliness and the like, provides an efficient and feasible way for green synthesis of methylamine hydrochloride, and has a wide application prospect.

The invention belongs to the technical field of reproductive medicine and clinical metabolism intervention, and particularly relates to a group of markers for diagnosing unexplained recurrent abortion and application thereof. Aiming at the clinical pain point that unexplained recurrent abortion (URSA) lacks accurate metabolic typing diagnosis indexes and targeted treatment means, based on detection of a large number of clinical samples and verification of cell experiments, direct association between down-regulation of levels of choline related metabolites and trimethylamine oxide (TMAO) of decidua tissues and the RSA is disclosed for the first time; the core effect of TMAO in-situ synthesis of decidua stromal cells (DSC) in regulation and control of the decidualization process is determined; meanwhile, an RSA indication screening system of joint detection of serum creatinine and decidua choline metabolism is constructed, a targeted TMAO targeted intervention scheme is formed in a matched mode, a diagnosis and treatment closed loop of RSA from precise typing to targeted treatment is achieved, and a brand new technical path is provided for clinically solving the URSA diagnosis and treatment problem.

The invention provides a screening method of a targeted drug for inhibiting accumulation of trimethylamine and / or trimethylamine-N-oxide. The screening method comprises the following steps: determining an action target on a metabolic pathway of trimethylamine and / or trimethylamine-N-oxide; if the target is protein, preliminarily screening candidate components based on the three-dimensional structure of the target; the candidate component is validated to confirm the targeted drug. According to the method, large-scale screening of targeted drugs aiming at targets can be achieved, the targeted drugs inhibit accumulation of trimethylamine and / or trimethylamine-N-oxide in the body by influencing the metabolic pathway of trimethylamine and / or trimethylamine-N-oxide, side effects are small, and the normal metabolic process of the human body is prevented from being influenced.

Provided is a synthesis method for azoxystrobin, comprising: in a water-oil system of an organic solvent and an aqueous solution of trimethylamine, a compound represented by formula I reacts with 2-cyanophenol to obtain azoxystrobin, wherein the molar ratio of the compound represented by formula I to trimethylamine is 1:(0.96-2). The synthesis method has high reaction efficiency, does not produce CO2, avoids the risks of entrainment and overflow, reduces the generation of side reactions and solid waste emissions and is environmentally friendly. In addition, the method does not require the use of solid sodium carbonate or potassium carbonate, and the material reaction system is an oil-water reaction system, so that the reaction efficiency is greatly improved, and the yield can also be maintained at 95% or more, thereby taking both the efficiency (timeliness) and the yield into account and easily achieving continuous reaction, and thus providing technical support for intelligent and unmanned production. Moreover, since trimethylamine can be recycled, the use of one raw material is reduced, and further there is no need for complicated treatment for mixed salts and waste water thereof, thereby significantly reducing the energy consumption.

The invention relates to the technical field of degumming agents, and discloses a preparation process of a degumming agent for a solar photovoltaic silicon wafer. The degumming agent comprises the following components in percentage by weight: 2-8% of tetramethylammonium hydroxide, 3-6% of organic alcohol amine, 0.5-1.5% of alkyl glycoside, 0.2-0.8% of a chelating agent, 0.5-3% of a functional additive and the balance of deionized water, the chelating agent is sodium gluconate; the functional additive comprises a sodium silicate corrosion inhibitor, a thickening agent and a penetrating agent; the preparation method comprises the following steps: S1, adding trimethylamine and epoxy chloropropane into tetrahydrofuran, carrying out stirring reaction at 60-65 DEG C for 8-15 hours, and removing a solvent to obtain a cationized intermediate; s2, adding the cationized intermediate into water, adding sodium carboxymethyl cellulose, uniformly stirring, heating and pressurizing to 120-130 DEG C, stirring and reacting for 8-12 hours, and removing the solvent to obtain the modified sodium carboxymethyl cellulose.

The invention provides a composition. The composition is prepared from probiotics, a plant extract and acceptable auxiliary materials according to a specific content ratio. Wherein the probiotics comprise the following components: Weizmannia coagulans AUSA001, Lactobacillus plantarum AUSA002, Bifidobacterium longum subsp. Longum FL006, and the probiotics comprise the following components: the Weizmannia coagulans AUSA001, the Lactobacillus plantarum AUSA002, the Bifidobacterium longum subsp. Longum FL006, the Lactobacillus plantarum AUSA002 and the Bifidobacterium longum subsp. Longum FL006. The plant extract comprises a kudzuvine root extract, a grape seed extract and a turmeric extract. The composition has a synergistic effect, can reduce the content of human intestinal trimethylamine and serum trimethylamine oxide, and is used for prevention or adjuvant therapy of related diseases.

The application relates to the field of catalytic synthesis, and discloses a methylamine synthesis method, which comprises the following steps: reacting methanol and ammonia in the presence of a zeolite catalyst treated by an organic alkali to generate a methylamine-containing stream; the acid amount of the zeolite catalyst treated by the organic alkali is 200-400 mu mol.g ‑1 The methylamine synthesis method can reduce the selectivity of trimethylamine in the reaction product, reduce the content of trimethylamine in the product, and ensure high methanol conversion rate.

This utility model belongs to the field of trimethylamine removal technology, specifically relating to a trimethylamine removal device, including a deamination tower bottom liquid cooler, a deamination tower reboiler, and a deamination tower condenser. The deamination tower reboiler and condenser are both connected to the deamination tower bottom liquid cooler via pipelines. A pressure relief pipe is connected to the deamination tower bottom liquid cooler, and a connecting nozzle is threaded onto the inner side of the upper opening of the pressure relief pipe. A pressure relief port is fixedly connected to the top of the connecting nozzle. By setting up the deamination tower bottom liquid cooler, reboiler, and condenser, online removal of trimethylamine is achieved. The pressure relief pipe on the deamination tower bottom liquid cooler utilizes a coordinated design of a tapered tube, elastic band, and plug to achieve rapid pressure relief of the trimethylamine gas. When the pressure inside the tower exceeds a threshold, the gas pushes open the plug to release pressure. After the pressure decreases, the elastic band automatically pulls back the plug to seal, requiring no manual intervention.

The application discloses a kind of high-efficiency vaporization equipment of TMA recovery, it is related to TMA recovery technical field.The main body component and top cover component are included, the main body component includes main cylinder, top cover component includes top cover body, carrier assembly for absorbing waste water and heating waste water is arranged on top cover body, shaking assembly for driving carrier assembly vibration and storage assembly for impurity recovery are arranged in main cylinder.The application is heated by the way of containing waste water, so that trimethylamine is preferentially vaporized into gaseous state, the recovery of trimethylamine is realized, the heating carrier further heats the water absorption carrier, the remaining impurities in the water absorption carrier are crystallized, the rotating shaft continuously drives the rotation of water absorption carrier and heating carrier, water absorption carrier and heating carrier contact with shaking assembly, so that the carrier frame shakes up and down as a whole, and the crystallized impurities are shaken off, thereby reducing the content of impurities in the sewage at the bottom of main cylinder, and the recovery efficiency of trimethylamine is improved.

The present application relates to a kind of cationic polymer coated copper-based catalyst and its preparation method and application, belong to catalyst technical field.The preparation method of the present application includes the following steps: S1, 5-bromo indigo and 5-bromo indole-2-ketone are reacted in acid solution to obtain 5,5 '-dibromo isoindigo;S2, 5,5 '-dibromo isoindigo, potassium hydroxide and 1,4-dibromobutane are dissolved in organic solvent to carry out reaction to obtain N,N-dibutyl-5,5-dibromo isoindigo;S3, N,N-dibutyl-5,5-dibromo isoindigo, trimethylamine hydrochloride and base are reacted in solvent to obtain double quaternary ammonium dibromo isoindigo;S4, copper nanoparticles suspension is added to the double quaternary ammonium dibromo isoindigo solution to carry out self-assembly reaction, and cationic polymer coated copper-based catalyst is obtained.The catalyst exhibits excellent electrocatalytic carbon dioxide reduction performance in acidic electrolytic system, and can be highly selective to prepare ethanol.

The invention discloses a GaN-Ni3 (HITP) 2 / PANI trimethylamine sensor and a preparation method thereof, and belongs to the technical field of gas sensors. The sensor comprises a GaN epitaxial wafer, electrodes are deposited on two sides of the surface of the GaN epitaxial wafer, Ni3 (HITP) 2 is compounded in the middle of the GaN epitaxial wafer through a solution self-assembly method, and a PANI film is compounded on the surface of the GaN epitaxial wafer compounded with the Ni3 (HITP) 2; according to the method, the GaN material is etched and compounded with PANI and Ni3 (HITP) 2, the sensitive characteristic to TMA is improved by fully utilizing the synergistic effect of different materials, and high-performance detection of ppb-level TMA at the room temperature is achieved; compared with a traditional TMA detection mode, the prepared GaN-Ni3 (HITP) 2 / PANI trimethylamine sensor has the advantages of being high in detection sensitivity, high in response and recovery speed, capable of achieving room-temperature detection and the like; the problems of poor stability, weak recovery performance and low sensitivity of a trimethylamine sensor at room temperature are solved.

The invention discloses a method for catalytically degrading trimethylamine by plasmas, which comprises the following steps: filling a discharge bed layer area of a plasma reactor with a MnO2-coated LaOx catalyst, and catalytically degrading trimethylamine by plasmas, the MnO2 (at) LaOx catalyst comprises a nanorod-shaped MnO2 carrier and lanthanum oxide nanoparticles uniformly loaded on the surface of the nanorod-shaped MnO2 carrier; the preparation method of the MnO2 (at) LaOx catalyst comprises the following steps: under stirring, adding an oxalic acid solution into a nanorod-shaped MnO2 carrier dispersion liquid, keeping stirring for 10-60 minutes, then adding a lanthanum nitrate solution, keeping stirring for a period of time, then taking a solid, washing, drying, and calcining at 300-500 DEG C to obtain the MnO2 (at) LaOx catalyst. The method has remarkable advantages in the aspects of improving the catalytic efficiency, reducing the energy consumption, reducing the environmental pollution, enhancing the stability, simplifying the preparation process and the like.

The invention discloses a method for removing trimethylamine through catalysis of a manganous-manganic oxide catalyst, and belongs to the technical field of atmospheric pollution control in environmental chemical engineering. The preparation method comprises the following steps: dissolving manganese acetate tetrahydrate in a mixed solution of ethylene glycol and water, heating, then adding a Na2CO3 solution in a nitrogen atmosphere, stirring for reaction, and then washing, drying and calcining to obtain a spherical manganous-manganic oxide catalyst; and finally, in a nitrogen atmosphere containing trimethylamine and oxygen, realizing catalytic removal of the trimethylamine by the spherical manganous-manganic oxide catalyst at 50-250 DEG C. By controlling the morphology of the manganous-manganic oxide catalyst, the obtained spherical manganous-manganic oxide catalyst can completely catalyze and decompose trimethylamine at a relatively low temperature (175 DEG C), and the spherical manganous-manganic oxide catalyst does not have an obvious inactivation phenomenon when the degradation reaction of the spherical manganous-manganic oxide catalyst on the trimethylamine is performed for 45 hours. When the trimethylamine is catalytically removed by the manganous-manganic oxide catalyst, the spherical manganous-manganic oxide catalyst has excellent nitrogen and carbon dioxide selectivity.

The invention belongs to the technical field of chemical separation and purification, and particularly relates to a purification process of trimethylamine. The invention aims to solve the problem of insufficient purity of the current trimethylamine product, especially the technical problems that the content of monomethylamine and dimethylamine exceeds the standard and the peculiar smell is obvious. Mesoporous silica gel subjected to sulfonyl chloride derivative surface functionalization modification is used as a selective adsorbent and is subjected to a contact reaction with a raw material trimethylamine, and monomethylamine and dimethylamine impurities are selectively removed; then carrying out catalytic hydrogenation on trimethylamine and a small amount of hydrogen together through a loaded metal catalyst, so that oxides in trimethylamine are reduced into trimethylamine and water; and finally, carrying out deep dehydration and purification on the product by using a high-hydrophilicity membrane by adopting a pervaporation membrane separation technology to obtain a high-purity trimethylamine product.

The invention provides application of a flavin monooxygenase 3 inhibitor in preparation of a medicine for preventing and / or treating acute pancreatitis, and belongs to the technical field of medicines. The flavin monooxygenase 3 inhibitor is methimazole or a pharmaceutically acceptable salt, a prodrug or a derivative of methimazole. Experimental results show that after the methimazole is orally taken, the nidus area of animal pancreatitis is obviously reduced, the pathological score is obviously improved, the in-vivo inflammation level is obviously inhibited, and the blood amylase and lipase levels are obviously reduced; the levels of pancreatitis factors and chemotactic factors are reduced, and the oxidative stress index is reduced. In addition, by combining methimazole with the traditional Chinese medicine monomer for inhibiting the trimethylamine oxide level, the curative effect is better. Compared with the prior art, the application has the advantages that the core regulation effect of the trimethylamine oxide in the pathological process of the acute pancreatitis is disclosed for the first time, the limitation of the traditional anti-inflammatory or enzyme replacement therapy is broken through, and the acute pancreatitis is treated by inhibiting the trimethylamine oxide level by inhibiting the flavin monooxygenase 3.

The utility model discloses a tail gas absorption tower, which relates to the technical field of tail gas treatment and comprises an absorption tower body, a gas outlet and a gas inlet, the gas outlet and the gas inlet are respectively positioned at the upper end and the lower end of the absorption tower body, and a water washing unit, a methanol washing unit and a dust removal unit are sequentially arranged in the absorption tower body from top to bottom. The dust removal bag is used for separating the filter chamber from the methanol washing unit; and the air inlet is communicated with the filter chamber. According to the utility model, alcohol washing and water washing are integrated in one absorption tower, so that methanol, ammonia, monomethylamine, dimethylamine, trimethylamine and the like generated in the methylamine production process are absorbed, the occupied area of the absorption tower can be reduced, and the tail gas treatment efficiency of the absorption tower is improved.

The invention provides a pet cleaning agent with dual functions of deodorization and softening and a preparation method of the pet cleaning agent, and relates to the technical field of pet supplies. According to the formula prepared by the invention, based on the principles of sterilization inhibition and neutralization degradation, a bactericide, a deodorant and a hair conditioner (a silicone oil conditioner and a cationic conditioner) are compounded to prepare the pet cleaning agent with dual functions of deodorization and softening. The pet hair conditioner can effectively improve the smoothness, bacteriostasis and deodorization performance and durability of pet hair, and can remove odor generated by ammonia gas, methyl mercaptan, isoamylamine, 3-hydroxyisovaleric acid, trimethylamine, 3-mercapto-3-methyl-1-butanol and 3-methylindole on the body surface of a pet.

This invention discloses a method for preparing doped tin dioxide nanocrystals that can be highly dispersed in any water-to-alcohol ratio. The preparation method includes the following steps: (1) adding trimethylamine oxide to an aqueous solution containing tin halide to produce a white precipitate and stirring; (2) subjecting the mixture obtained in step (1) to a hydrothermal reaction at 120–200°C for 3–24 h, separating the solid and liquid phases after the reaction, and dispersing the solid phase in pure water, pure alcohol, or a water-to-alcohol mixture with any water-to-alcohol ratio to obtain a halogen-doped tin dioxide dispersion; (3) adding an organic base stabilizer to the halogen-doped tin dioxide dispersion and mixing to obtain halogen-doped tin dioxide nanocrystals that are highly dispersed in pure water, pure alcohol, or a water-to-alcohol mixture with any water-to-alcohol ratio. The preparation method of this invention is simple and inexpensive, broadens the application field of tin dioxide, and has important application value.

The application discloses a nickel-coupled hybrid nanometer carbon core-shell structure cocatalyst, a preparation method and application thereof, and comprises the following steps: preparing a nickel salt N,N-dimethylformamide (DMF) solution (one); fully mixing ethylenediaminetetraacetic acid (EDTA), hybrid nanometer carbon (HC), trimethylamine and DMF to obtain a solution (two); fully mixing the solution (one) and the solution (two) to obtain a precursor of nickel (Ni) coupled with HC, and then centrifuging, washing, drying and heat treating by using a microwave tube furnace to obtain the Ni coupled with HC core-shell structure cocatalyst; the preparation method is simple, the non-noble metal Ni is compounded with the HC, and the cost is low; the prepared cocatalyst has a compact core-shell heterojunction interface, a high photo-generated carrier separation efficiency and a large number of hydrogen evolution active sites; after being compounded with graphite phase carbon nitride, the photocatalytic hydrogen production activity of the nickel cocatalyst coupled with the HC is significantly improved as compared with the nickel cocatalyst not coupled with the HC.

The invention discloses an ergothioneine trimethylamine lyase mutant and application of the ergothioneine trimethylamine lyase mutant in detection of histidine betaine in saliva. L-histidine betaine is catalyzed by ergothioneine trimethylamine lyase to be hydrolyzed into urocanic acid, the light absorption value of the urocanic acid at 290 nm is detected by a colorimetric method, and the content of L-histidine betaine in saliva can be determined. The method is high in sensitivity, and detection of 12.5-100 mg / L histidine betaine in a saliva sample can be completed within 1.5 hours. The method is simple and convenient to operate and can be used for quickly judging the metabolic state of human ergothioneine.