146results about How to "Reduce method steps" patented technology

The invention discloses film-forming polysiloxane emulsion and a preparation method thereof. The preparation method of the film-forming polysiloxane emulsion comprises the following steps of: dissolving 0.02-20 parts by weight of composite surfactant to 100 parts of water; adding 10-60 parts by weight of organo-silicone monomers, shearing the organo-silicone monomers by a shearing and emulsifying stirrer, and homogenizing the organo-silicone monomers under 20Mpa-60Mpa to obtain organo-silicone monomer emulsion; raising the temperature of the organo-silicone monomer emulsion to 70 DEG C to 90 DEG C, adding 0.01-10 parts of catalyst for reacting for 4-6 hours, cooling the reaction liquid to 40 DEG C to 60 DEG C, adding 0.5-5 parts of a cationic surfactant and 0.05-20 parts of a cross-linking agent for reacting for 1-3 hours cooling the reaction liquid to 20 DEG C to 30 DEG C and adding acetic acid to neutralize the emulsion to be neutral so as to obtain the film-forming polysiloxane emulsion. The method for preparing the film-forming polysiloxane emulsion is less in steps, simple to operate, low in cost and high in conversion rate. The obtained film-forming polysiloxane emulsion can be placed for more than three months at normal temperature without layering or emulsion-breaking.

The invention discloses crosslinked polysiloxane / acrylic ester compound emulsion, and a preparation method and application thereof. The preparation method comprises the following steps: performing shear emulsification and high-pressure homogenization on an organic siloxane monomer, water and a composite emulsifier to prepare a siloxane monomer emulsion; adding a crosslinking agent to prepare a crosslinked polysiloxane emulsion; and compounding the crosslinked polysiloxane emulsion and a polyacrylic ester emulsion, which is prepared by a continuous emulsion polymerization method, by a simple process to obtain the stable and high-compatibility crosslinked polysiloxane / acrylic ester compound emulsion. The crosslinked polysiloxane / acrylic ester compound emulsion has the characteristics of excellent hydrophobicity, low-temperature resistance, high-temperature resistance, water tolerance, alkali resistance, stain resistance and the like of olysiloxane emulsion as well as the characteristics of film-forming property, weather resistance, ozone resistance, uvioresistant capability and the like of acrylic emulsion and can be applied to building paint of inner walls, outer walls, floors, bathrooms and the like.

The invention belongs to the field of polysiloxane microemulsion, and discloses an electrolyte-resistant and high-solid content polysiloxane microemulsion, and a preparation method and application thereof. The preparation method comprises the following steps of dissolving a composite surfactant in water, adding a part of organic siloxane monomers, and performing shearing emulsification and high-pressure homogenization to obtain siloxane monomer pre-emulsion; adding electrolyte, performing heating and stirring, and adding a catalyst for thermostatic reaction; adding dropwise the residual siloxane monomers, continuing reaction, cooling a reaction product to room temperature, and neutralizing the reaction product to be neutral to obtain the polysiloxane microemulsion. According to the polysiloxane microemulsion, and the preparation method and application thereof, the compound surfactant is used, so that the using amount of an emulsifier is reduced, the stability of an emulsion system is improved, the conversion rate of the emulsion system is increased, and the solid content is increased; the polysiloxane microemulsion has the characteristics of high hydrophobicity, low-temperature resistance, high-temperature resistance, water resistance, electrolyte resistance and alkali resistance, is free of a metal catalyst, and can be widely applied to the fields of textile, leather, cosmetics, medicines, buildings and the like.

The invention discloses a method and device for supporting a weak adhesion bond soft rock roadway. The method includes that step 1, a drilling machine is adopted for drilling holes; step 2, a reamer bit and a drilling stem are connected, and the bottom of a drilled hole is chambered; step 3, an anchoring agent and an anchor rod are placed in the drilled hole, the anchor rod and the drilling machine are connected, the drilling machine drives the anchor rod to rotate and stir the anchoring agent, after the anchoring agent is solidified, a chambering portion is full with the anchoring agent to form a solid structure in a reverse wedge shape, and the solid structure is used for fixing an anchoring section of the anchor rod; and step 4, a tray is arranged on top of the drilled hole, a nut is used for screwing a free end of the anchor rod tightly, and pre-tightening torsion meets design value. The device is a chambering reamer bit comprising a casing, a cutter and a cutter control device, wherein one end of the casing is a connector, the cutter is connected with the bottom of the connector in pivoted mode, and the cutter control device is connected with the cutter and controls the cutter to be screwed out from the casing or withdrawn. By means of the device and method, an effect of the anchor rod is good.

The invention discloses a carbon-nanotube-containing polymer nanocomposite, which comprises the following components in parts by mass: 1 part of carbon nanotube, 0.5-10 parts of ionic liquid and 5-2,000 parts of polymer. The invention further discloses a preparation method of the nanomaterial. The invention has the advantages that: (1) the carbon nanotube is coated with the ionic liquid, so that the conjugated structure of the carbon nanotube is not broken and superior physical property of the carbon nanotube per se is kept; (2) strong mechanical action is not used, so that fracture of the carbon nanotube is not caused and the length-diameter ratio of the carbon nanotube is lowered; and (3) the method for preparing the carbon-nanotube-containing nanocomposite has a small number of steps and high efficiency, is implemented without any other chemical reagents, and is simple, practicable and environment-friendly.

The present invention discloses a manufacturing method of Sip (System In a Package) module with an electromagnetic shielding structure and a device. An SiP module to be subjected to coating of electromagnetic shielding glue is manufactured, The SiP module comprises a substrate, a plurality of electronic elements and a plastic package layer, the substrate comprises a support layer, a conductive layer and an insulation layer, the insulation layer is internally provided with an interval conductive terminal and an edge conductive terminal, the lower end faces of the two conductive terminals are connected with a conductive layer, and the upper end faces of the two conductive terminals are in level in the upper end face of the substrate; the electronic element is welded at the upper surface of the substrate, and the electronic element having an anti-electromagnetic interference requirement is independently arranged at one side of the interval conductive terminal; the plastic package layer coats the electronic element; the plastic package layer is internally provided with an interval shielding groove and a conformal shielding groove cutting through the plastic package layer from top to bottom, and shielding glue fills in the interval shielding groove and the conformal shielding groove in a vacuum coating mode. The SiP module manufacturing method can allow the interval shielding layerand the conformal shielding layer at the same time, is simple in coating device, low in manufacturing cost and few in manufacturing process, can save the glue materials and can reduce the product cost.

The invention discloses an air-conditioning load prediction method based on big data. The method includes the steps: 1) acquiring outdoor temperature t in DEG C of a site with an air conditioner at a simulated prediction moment; 2) acquiring a temperature interval [t-s and t+s] based on a predetermined prediction step size s in DEG C and the outdoor temperature t; 3) screening data in the temperature interval from historically accumulated big data of cold or heat load measured values, total power of lighting and devices, the number of indoor people, open water surface area, indoor and outdoor air enthalpy differences and indoor and outdoor temperature differences of the air conditioner running under stable conditions; 4) calculating final load value of the prediction moment based on screened date. Based on a lot of gradually accumulated historical data of practical cooling capacity and heating capacity of the air conditioner running under the stable conditions, models for calculating cold or heat loads at the simulated prediction moment are continually optimized, and the built models are more accurate with the passage of time. The invention further discloses an air-conditioning load prediction system based on the big data.

A health-care red bayberry wine is prepared from high-quality spirit, red bayberry fruit, crystal sugar and white sugar through proportional mixing, loading in jar, sealing, laying aside for 5-6 months while stirring, every 15 days, filtering, adding edible essence, sealing, and laying aside for 2 months.

The invention relates to a longitudinal concrete member extending vertically such as a device for wind power generation tower possessing an inner template, an outer template; a gap is between the inner template and the outer template; height is smaller than concrete member (20) to be built. Multiple pumps are employed to pumping concrete into gap by a high pressure, and the concrete member (20) extrudes vertically from the gap during concrete curing process. A top cover (24) is conveyed upward following concrete member rising, the top cover is used for lifting and mounting all kinds of member.

The invention belongs to the field of silicon rubber micropowders, and discloses a high-dispersity aging-resistant high-impact-resistance cationic silicon rubber micropowder, and a preparation method and application thereof. The preparation method comprises the following steps: polymerizing organosiloxane monomer under the actions of a composite surfactant and a catalyst to obtain a linear polysiloxane emulsion, sequentially adding a crosslinking agent and a reinforcing agent to obtain an organic silicon rubber emulsion, and carrying out spray drying on the emulsion to form, thereby obtaining the cationic silicon rubber micropowder. The cationic silicon rubber micropowder is prepared by the emulsion polymerization method; the preparation method has the advantage of fewer steps, lower cost, higher safety and environment friendliness; and the silicon rubber micropowder has the advantages of favorable impact resistance, favorable dispersity and favorable compatibility, and can be used in processing modification of anionic substrates to enhance the impact resistance of the material.

The invention discloses a preparation method of a boron-nitrogen dual-ingredient self-doping three-dimensional drape graphene electrode material. The method comprises the following operation steps: (1) an amino boron hydride compound and catalyst metal salt are mixed, and are dissolved in a solvent; heating and stirring are performed until dry powder is obtained; (2) heat treatment is performed in inert gas; then, the powder is cooled to room temperature; (3) an acid solution is added; heating, stirring and filtering are performed; filter residue is cleaned to a neutral state; drying is performed to obtain boron-nitrogen dual-ingredient self-doping three-dimensional drape graphene. The preparation method has the advantages that the steps are fewer; reaction equipment is simple; the reaction conditions are easily realized; the graphene doping amount and type can be easily controlled; the cost is low; the large-scale preparation is easy; the prepared boron-nitrogen dual-ingredient self-doping three-dimensional drape graphene has high activity and good stability, and shows good electrochemical performance in lithium ion battery negative electrodes and fuel oxygen reduction catalysts; huge economic benefits and values are realized.

The invention relates to a method for extracting rare noble metals, which comprises the following steps: mixing the raw material containing rare noble metals with metal chloride; treating the mixture with a chlorine / carbon monoxide gas mixture at about 450-800 DEG C; cooling the mixture, and extracting with hydrochloric acid; and filtering and washing. The method has the advantages of high extraction rate, good reproducibility and low time consumption, can be used for basically recycling rare noble metals in the raw material, and can also be used for accurate quantitative analysis on the metals in the raw material. The method provided by the invention is especially used for treating waste automobile catalysts.

The invention provides a stator potting method which comprises the following steps: (1) preparing a sealant; (2) sealing two axial ends of the stator, wherein a potting opening is reserved in one end; (3) applying the sealant to the outer side face of the axial direction of the stator; (4) coaxially inserting a sealing plug core in the middle of the stator, wherein the sealing plug core is in sealed contact with the inner side face of the stator; (5) potting into the stator from the potting opening; (6) feeding the stator into a curing furnace for performing high-temperature curing; and (7) cooling and demolding. The invention further provides a motor comprising the stator produced by the stator potting method, wherein glue is potted into the stator of the motor. The stator potting method disclosed by the invention has the advantages that the stator in easy adhesion with oil is potted by utilizing the sealant so as to form a smooth stator surface, and the cleaning difficulty of the motor is greatly reduced on premise of not influencing the motor performance.

The invention discloses a brewing method for tartary buckwheat white spirit. The brewing method comprises the following steps: selecting materials: selecting tartary buckwheat with good quality and full seeds; washing: cleanly washing the tartary buckwheat by mountain spring water; spraying the water and accelerating germination: pouring the washed tartary buckwheat seeds into a bamboo basket and covering by a cotton quilt to guarantee light shielding and ventilation; spraying the tartary buckwheat seeds every 4-5 hours by using warm water with the temperature of 20-25 DEG C until tartary buckwheat germs grow for 1cm-3cm; steaming: steaming the tartary buckwheat seeds in the mountain spring water and controlling the water temperature in a range of 78-82 DEG C until shells of the tartary buckwheat seeds are opened; drying: fishing out the steamed tartary buckwheat and cooling to 25-30 DEG C; adding apple butter; fermenting: fermenting for 15 days by using a yeast in a sealed manner; and distilling: taking the tartary buckwheat out and distilling to obtain base liquor of the tartary buckwheat white spirit. The tartary buckwheat white spirit brewed by the brewing method disclosed by the invention has good color luster, clarity, flavor, taste, style and the like; particularly, the apple butter is added so that the tartary buckwheat white spirit is mellow and tasty.

The present invention pertains to a method for producing a colloidal suspension of zirconia particles, comprising the following successive steps: a) subjecting a mixture of zirconium oxychloride and an alkali metal halide in an aqueous solvent to hydrothermal treatment at a temperature above 150° C., so as to obtain a suspension in the form of a two-phase mixture comprising a slurry and a supernatant, b) without first peptizing it, desalting said suspension so as to form a colloidal suspension of zirconia.

The present invention is parasiticidal pet collar material and the making process of pet collar. The parasiticidal pet collar material includes one active component and one matrix component in the weight ratio of 0.03-0.08 to 1. The active component consists of pentmethrin 0.5-1 weight portions, refined dipterex 1 weight portions, synthetic borneol 1 weight portions, silica 0.5-1 weight portions and adhesive 1 weight portions; and the matrix component consists of PVC 70-75 weight portions, dioctyl phthalate 15-18 weight portions, dibutyl phthalate 7-15 weight portions. The present invention has the advantages of ensured material source, excellent slow release effect, last acting, high parasiticidal effect, etc.

The invention discloses a method for measuring the daily mean stable carbon isotope composition of atmospheric carbon dioxide, which is characterized by comprising the steps of (I) measuring sodium bicarbonate produced by different manufacturers as tracer agents; (II) adding sodium bicarbonate into a nutrient solution respectively, and setting the concentration of sodium bicarbonate in the nutrient solution to 10mM and the pH value to 8.30; (III) cultivating the plants with same growth cycle by use of the prepared solution at the same time, and after 24 hours of cultivation, separately measuring the values of the stable carbon isotope composition (delta)13C in two isotope-labeled nutrition solutions, namely a value of (delta)1 and a value of (delta)2; (IV) substituting the measured values of (delta)C1, (delta)C2, (delta)1 and (delta)2 into an equation, and calculating the proportion fB of added sodium bicarbonate to total inorganic carbon in the solution; (V) judging whether the value of fB is less than 0.6, fetching the measured values obtained by an experiment when the value of fB is less than 0.60, substituting the measured values into an equation, and calculating the average value of inorganic carbon (delta)13C entering the culture solution in atmospheric carbon dioxide within the time period (delta)a; (VI) substituting the calculated (delta)a into an equation (delta)Ca=(delta)a+(Delta)CO2(air)-HCO3(aq), and calculating the daily mean stable carbon isotope composition (delta)Ca of atmospheric carbon dioxide.

The invention discloses an identification method for adaptability of a plant to the low-phosphorus environment. The method is characterized in that hydroponics is conducted on the plant to be surveyed; then, after starving culture is conducted on the plant for 48 h in a culture solution without inorganic phosphorus, a dihydrogen phosphate ion absorption experiment is conducted, according to the Michaelis constant and the minimum concentration, obtained in the dihydrogen phosphate ion absorption experiment, of dihydrogen phosphate ion absorption of the plant to be surveyed, the available phosphorus content of the riphzosphere environment of the plant to be surveyed grown in the environment to be tested, and the relative absorption rate of dihydrogen phosphate ions of the plant to be surveyed is further calculated according to the Michaelis constant and the minimum concentration of the dihydrogen phosphate ion absorption and the available phosphorus content of the riphzosphere environment; finally, the adaptability of the plant to the low-phosphorus environment is evaluated according to the obtained relative absorption rate of the plant to be surveyed. The method is few in steps, simple in calculation, reliable in data and capable of rapidly identifying the environmental adaptability of different plants to the same low-phosphorus environment and provides a technological support for sorting plants suitable for growing in karst and terricolous floating plants.

The invention relates to a preparation method of poly(N-isopropylacrylamide-methacrylic acid) porous microspheres with magnetic responsiveness and temperature sensibility. The preparation method comprises the following steps: firstly, preparing polymeric porous microspheres with the temperature sensibility by using an alkali-acid step-by-step treatment method, and then forming Fe3O4 nanoparticles in situ on the surfaces of the porous microspheres and in pore channels of the porous microspheres by using a coprecipitation method. The preparation method has the beneficial effects that the polymerization process is completed in one pot, and the aftertreatment process is relatively simple. A poly(N-isopropylacrylamide) skeleton is capable of providing temperature sensibility for a compound system; the Fe3O4 nanoparticles formed in situ on the surfaces of the polymeric porous microspheres and in the pore channels of the polymeric porous microspheres are capable of providing good superparamagnetism for the polymeric microspheres; and porous structures in the polymeric microspheres are capable of providing convenient conditions for applications of the polymeric porous microspheres in terms of biological medicine controlled release and magnetic targeting drug delivery.

The invention relates to the field of manufacture, in particular to an air valve nozzle core manufacture method, which comprises the following steps of: (1) blanking, (2) punch forming by a cold header, (3) cutting by an automatic lathe, (4) external screw thread processing, (5) internal screw thread processing and (6) product surface oxidation treatment. An air valve nozzle core manufactured by the method has the advantages that the steps are few, and the production efficiency is high.

The invention provides a metal organic framework with a polymer grafted on the surface and a preparation method thereof. A linear polymer is grafted on the surface of the metal organic framework containing amino through a small molecular connecting agent, wherein the weight-average molecular weight of the polymer is 5,000-500,000, and the particle size of the metal organic framework is 50-1000nm;and the small molecular connecting agent is anhydride containing double bonds. Based on post-synthesis chemical modification, the provided preparation method of the metal organic framework has the advantages of few steps, low cost, simple operation, high density of grafted polymer, and wide weight-average molecular weight range, and is suitable for preparing a plurality of amino-containing metal organic frameworks and olefin or olefin derivative monomers. The prepared metal organic framework not only has the advantages of an existing metal organic framework / polymer composite material, but alsoimproves the dispersity of the metal organic framework in a polymer body material, so that the actual effect of doping the polymer body material by the metal organic framework is improved.

The invention discloses a method for preparation of lithium tantalate nano-powder by a hydrothermal process. The method includes: using deionized water as a reaction solvent, adding a lithium source and a tantalum source, ensuring the mole ratio of tantalum ions to lithium ions at 1:(1-8), carrying out reaction for 8-24h in an autoclave, keeping the reaction temperature at 200-260DEG C, and at the end of the reaction, firstly conducting washing by deionized water, and then performing washing by an alcohol solvent, thus obtaining the lithium tantalate nano-powder. The lithium source is LiOH or Li2CO3, and the tantalum source is Ta(OH)5 or Ta2O5. The method provided by the invention adopts different lithium sources and different tantalum sources as the raw materials, and takes deionized water as a reaction solvent to synthesize the LiTaO3 nano-powder. The prepared LiTaO3 powder has a regular shape, fine, complete and uniform grains, high purity, no aggregation or less agglomeration, and has no need for high-temperature calcination treatment. The method provided by the invention has the advantages of fewer steps, simple preparation, short reaction time, low reaction temperature, and is suitable for mass production.

The invention relates to an infrared spectrum fast detection method for the isotope abundance of 15N tracer urea. The conventional detection method is low in speed and is complicatedly operated. The method comprises the following steps of: grinding 15N tracer urea to be detected into a powder sample; tabletting the powder sample and potassium bromide to obtain a sample; performing infrared transmission spectrum scanning on the prepared sample to obtain a transmission spectrum of the sample; converting the transmission spectrum of the sample into an absorbance spectrum; and substituting the absorbance of the sample of which the wave numbers are detected at the positions of 3,411cm<-1>, 3,175cm<-1>, 1,697cm<-1>,1,656cm<-1>, 1,628cm<-1>, 1,601cm<-1>, 1,478cm<-1> and 1,442cm<-1> into a formula to acquire the isotope abundance Y of the sample. The method is convenient to use; and the isotope abundance of the 15N tracer urea can be fast and effectively measured, so that the method has a good economic benefit.

The invention provides a polyether block copolymer which has a structure as shown in formula (I). The polyether block copolymer provided by the invention has an amphiphilic group, which provides the obtained polyether block copolymer with amphiphilicity, and thus the polyether block copolymer can be self-assembled into nanoparticles and can be used as a drug carrier and the like; end groups and / of side groups of the polyether block copolymer provided by the invention have double bond function groups, and thus through reactions of a mercapto group with the double bonds, the modification of the polyether block copolymer is realized; the polyether block copolymer is provided with functions of tissue and cell targeting, environment responsiveness and the like; therefore, the polyether block copolymer provided by the invention has high application value and wide application prospects in biomedicine. Experiment results show that the polyether block copolymer provided by the invention can be modified by folic acid further, and the obtained folic acid-modified polyether block copolymer has cell targeting; the method for preparing the polyether block copolymer provided by the invention has a yield of about 90%.

The invention discloses a method for utilizing neutral protease to extract and purify astaxanthin in shrimp shell and crab shell. Firstly fresh shrimp shell or crab shell is smashed and prepared to bean enzyme solution, the shrimp shell or crab shell is subjected to an enzymatic hydrolysis reaction with the enzyme solution, a solid is mixed with an organic solvent, the astaxanthin is extracted under the certain condition, the astaxanthin is obtained through filtration, evaporation and drying, and the astaxanthin is subjected to qualitative and quantitative analysis by using high performance liquid chromatography. The yield rate of the astaxanthin in the shrimp shell of pandalus borealis is 145 microgram / g, the purity of astaxanthin crude extract is 1.12 mg / g, and the content of the purified astaxanthin is 92%. The yield rate of the astaxanthin of shrimp shell of procambarus clarkia is 294 microgram / g, the purity of the astaxanthin crude extract is 2.06 mg / g, and the purity is as highas 95% after the crude product of the astaxanthin extract is purified. The method has the advantages that the price of the raw materials is low, the reaction condition is moderate, the method is simple to operate, easy to popularize and produce and is environmentally friendly. The method can not only rapidly extract and obtain the astaxanthin monomer, but also the relatively high extraction rate,the stability and the purity are high.

The invention relates to a treatment process of manufacturing an antique artistic flowerpot, which comprises the following steps: firstly adopting the conventional manufacturing method to press a plastic flowerpot body the surface of which is provided with a concavo-convex pattern; then selecting a paint the color of which can form color contrast with that of the flowerpot body to carry out spraying on the surface of the flowerpot body; and finally selecting another paint the color of which can forms color contrast to carry out brushing on the pattern of the concavo-convex part on the surface of the flowerpot body to make the color of the patter of the concavo-convex part form stronger color contrast with that of the sunk part or the non-convex part of the surface of the flowerpot, and after completing brushing, obtaining the plastic flowerpot product with the antique color ornamental effect. The whole treatment process completely does not use the diluent to scrub without wasting water resources, has no industrial sewage discharge, and is beneficial for saving water resources and protecting the natural environment. And the method has simple steps and easy realization. The produced artistic flowerpot has the advantages of excellent antique effect, fastness, good durability and strong stereoscopic effect.

The invention provides a fluorite pellet production method. The fluorite pellet production method comprises the following steps that S1, wet fluorite powder is prepared; S2, the prepared wet fluoritepowder is poured into a rotary kiln, and the wet fluorite powder is dried through the rotary kiln; S3, a storage container is prepared, the fluorite powder dried in the rotary kiln in the step S2 is discharged into the storage container, and dust generated during drying in the step S2 is collected through a dust collection system and discharged into the storage container; S4, the fluorite powder in the storage container in the step S3 is poured into a dry powder weighing machine. By means of the fluorite pellet production method, fluorite pellets can be quickly produced, no harmful gas is discharged, a good environment protection function is achieved, operation is simple, the practicability is high, time and labor are saved, method steps are reduced, the production cost of a company is reduced, requirements of different factories are met, and the using effect of the fluorite pellets is improved.

The invention belongs to the technical field of material synthesis, and particularly relates to a method for preparing lithium sulfide through solid-liquid mixing and heating. The invention disclosesa method for preparing high-purity lithium sulfide in order to overcome the defects that the demand of a scientific research institution for lithium sulfide is increased and an existing preparation method is tedious in step and harsh in condition. According to the method, the lithium sulfide powder with relatively high purity can be obtained only by simply mixing and heating the raw materials andcarrying out subsequent purification treatment, the preparation method provided by the invention is simple and convenient, industrial production is easy to realize, the manufacturing cost is low, andthe purity of the obtained lithium sulfide is relatively high.

The invention relates to a method for preparing a composite photocatalyst CdS / ZIF-8 by a one-pot method, which comprises the steps of S1, dissolving alcohol-soluble zinc salt and cadmium salt in methanol, stirring until the solution is clear and transparent to obtain a first solution, dissolving 2-methylimidazole in methanol, and stirring until the solution is clear and transparent to obtain a second solution; S2, quickly pouring the second solution into the first solution, stirring to obtain a mixed solution, and standing and reacting the mixed solution for a period of time; S3, adding alcohol-soluble sulfide into the mixed solution, and reacting while stirring; and S4, after the reaction is finished, separating precipitates, washing and drying to obtain the composite photocatalyst CdS / ZIF-8. The method has the advantages of few steps and simple process, and is suitable for industrial application. Experiment tests find that compared with pure CdS, the prepared CdS / ZIF-8 composite catalyst shows more excellent hydrogen production performance and cycling stability, the CdS / ZIF-8 composite catalyst has a wide industrial application prospect, and an important reference basis is provided for catalyst design.

The invention discloses a synthetic method of high-purity asymmetrical dialkyl phosphinic acid, belonging to the technical field of synthesis of organic phosphorus compound. The synthetic method comprises the steps of carrying out addition reaction of free radials of large-steric-hindrance mono-olefine and phosphinic acid, so as to synthesize mono-alkyl phosphinic acid; and adding small steric-hindrance mono-olefine, and carrying out free radial addition reaction, so as to generate asymmetrical dialkyl phosphinic acid. The obtained product is subjected to washing by water, alkaline solution, acid solution, and saturated saline, drying and filtering, and then subjected to reduced pressure distillation or rotary evaporation so as to remove the un-reacted olefin, thereby obtaining high-purity asymmetrical dialkyl phosphinic acid. The synthetic method provided by the invention is simple in operation, mild in reaction condition, easy in implementation, and high in yield, and is suitable for mass production; and the product purification is easy, and the purity of the product is high.