50results about How to "Experimental operation safety" patented technology

The invention discloses a novel fume hood. The fume hood comprises a body, wherein the body is provided with an electric air valve; a lifting safety sliding door is arranged on the front of the body; and a face velocity sensor is also arranged on the front of the body. The fume hood also comprises a central control system electrically connected with the electric air valve, the safety sliding door and the face velocity sensor, wherein the face velocity sensor monitors pressure changes in the body after the safety sliding door is lifted, converts the values of pressure changes in the body into electrical signals and transmits the electrical signals to the central control system; and the opening angle of the electric air valve and lifting of the safety sliding door are controlled by the central control system. The fume hood has the following beneficial effects that: energy consumption and air loss in the laboratory are greatly reduced so that a relatively stable environment is maintained for experiments, thus achieving the aims of energy conservation and environmental protection and greatly improving the comfort level and environmental protection property of the laboratory.

The invention relates to a preparation method for a graphene loaded cobalt nickel phosphide composite material. The method includes: dissolving a nickel salt and a cobalt salt in deionized water, putting graphene oxide in deionized water to conduct ultrasonic treatment into a homogeneous solution, mixing the two fully, then transferring the mixture into a polytetrafluoroethylene lining, then adding red phosphorus, finally performing water hydro-thermal treatment, and subjecting the obtained product to vacuum drying, thus obtaining the graphene loaded cobalt nickel phosphide composite material. The method provided by the invention has the advantages of environment friendliness, simple and safe operation and the like.

The atmospheric cold plasma microbe mutagenesis method belongs to the field of microbe mutagenesis technology, and features the cold plasma mutagenesis of microbe strain to denature. The microbe strain may be pronucleus microbe or eukaryotic microbe; the atmospheric cold plasma may have discharging medium of air, nitrogen or helium with discharge period of 10 s to 10 min, applied voltage of 1-100 kV and frequency of 0-15 MHz; and mutagenesed microbe may be in suspension or plate. Compared with other physical and chemical mutagenesis method, the present invention has the advantages of simple apparatus, low cost, operation safety and high mutagenesis effect, and may be applied widely in industrial microbe breeding.

The invention discloses a method for quantificationally analyzing and detecting the components of a textile, in particular to a method for quantificationally analyzing the double-component fiber textile containing mulberry silk. The invention belongs to the textile detection technical field and comprises the following steps that: the sample which is quantificationally analyzed is preprocessed, the mulberry silk component in the sample is dissolved and is eliminated by the water solution of calcium nitrate with a mol ratio of 1:7 to 14; after the fiber component which is not dissolved is separated, the fiber component which is not dissolved is washed, dried, cooled and measured to determine the component, according to the mass difference between the sample before the dissolution and the fiber component which is not dissolved, the content of the mulberry silk component is determined. The method is suitable for the quantificational analysis of the mulberry silk, the other protein components and the nonprotein components and has the advantages of accurate test result, wide applicability, convenient operation, safe and non-toxic property and environment protection.

The invention provides a chitosan loading copper complex type nano-composite photo-thermal agent and a preparation method thereof, and belongs to the technical field of functional materials. The method comprises the steps of ultrasonically dissolving chitosan, copper salt and a polycarboxylic radial compound; dropwise adding a sodium hydroxide solution to the solution while agitating; regulating the pH of the mixed solution to be 3.2 to 3.6, wherein the mole ratio of used chitosan to copper salt to the polycarboxylic radial compound is 1: (1400-5800): (4500-7500); centrifuging the solution to separate out a copper complex loaded chitosan nanoparticle composite which is the chitosan loading copper complex type nano-composite photo-thermal agent with the photo-thermal converting performance. The water-soluble copper complex containing chitosan nanoparticle composite of different size can be applied to photo-thermal treatment; sufficient heat energy can be provided for photo-thermal tumor treatment, and the requirement of ablating tumor without damaging healthy tissue and organs can be met.

The invention relates to a preparation method of an iodine atom-substituted bis-fluorophenyl heterocyclic conjugated monomer. The preparation method comprises the following steps: firstly enabling a chemical compound with a bis-fluorophenyl heterocyclic conjugated structure to be reacted with lithium diisopropylamide, then adding an iodine elementary substance into a reaction system and finally introducing iodine atoms onto a benzene ring of the bis-fluorophenyl heterocyclic conjugated monomer. According to the method, the use of fuming sulfuric acid and other hazardous reagents is avoided, the synthetic efficiency and the experimental operation safety are improved, the yield is much higher than that obtained by a traditional iodization method, and the scale preparation and production are facilitated.

The invention provides a photocatalytic composite material with p-n heterojunction, and belongs to the field of organic pollutant treatment. The narrow-band-gap photocatalytic composite material withp-n heterojunction disclosed by the invention improves deficiency of a single catalyst, has a small band gap energy (1.87 eV), has a large absorption threshold on visible light, and has enhanced lightutilization efficiency. The p-n heterojunction caused by bending of the energy band increases the hole transfer ability, inhibits electron-hole recombination, improves the separation efficiency of photogenerated electrons and holes, prolongs the carrier lifetime and enhances the catalytic activity. Under visible light, the photocatalytic composite material has good degradation effects on organicpollutants in water, such as MO, MG, BPA, tetracycline hydrochloride, etc. At the same time, the narrow-band-gap photocatalytic composite material with p-n heterojunction disclosed by the invention can settle in water through standing, so that the narrow-band-gap photocatalytic composite material can be separated from an aqueous solution, and thus the narrow-band-gap photocatalytic composite material is beneficial to recovery and reuse of materials, has good regenerative capacity and can be recycled.

The invention discloses an experimental device for testing heat exchange properties at low temperate within wide Reynolds number range, comprising a compressor, a flow adjusting and allocating system, a helium cooling segment, a finned chip test segment and a measurement and acquisition system; three levels of flow adjustment are adopted herein, two mass-flow controllers are connected in parallel for measuring, Reynolds number testing precision is high, and the measurement range is wide; a scheme where covering with heat-insulating boards is performed and a scheme of placement in a high-vacuum multilayer heat-insulating environment are used to lower thermal balance errors, and heat transfer factor testing precision is high; temperature, pressure, flow and power values of the finned chip test segment are measured dynamically in real time during testing, heat transfer factor and friction factor are calculated in real time in the computer, and comparison with existing conclusions is facilitated; a temperature alarm monitor is arranged in the a control panel, so that operational safety and effectiveness of the device are ensured.

The invention relates to a nickel metaphosphate micro-nanomaterial as well as a preparation method and an application thereof. The micro-nanomaterial has a nano sheet array structure, and the lamellar thickness of nano sheets is less than 20nm. The nickel metaphosphate micro-nanomaterial is prepared through the preparation method comprising the following steps: dissolving a soluble nickel salt and weak base molecules in a solvent to react together with carbon cloth to obtain a nickel-containing precursor / carbon cloth complex, and then performing heat treatment on the nickel-containing precursor / carbon cloth complex and a phosphate compound in an inert atmosphere to obtain the nickel metaphosphate micro-nanomaterial. Based on a structure duplication thought, the invention adopts a two-step method to achieve preparation of a micro-nanostructure and growth of a nickel metaphosphate crystal phase, respectively, the preparation of the nickel metaphosphate micro-nanomaterial with a single crystal phase is achieved, the experiment operation is simple and safe, and scale production and application can be achieved. The prepared nickel metaphosphate micro-nanomaterial has a significant pseudocapacitance characteristic, and the specific capacitance is greater than 2000F / g when the discharge current is 1A / g, so that the nickel metaphosphate micro-nanomaterial has a good potential application prospect in the aspect of electrochemical energy storage.

The invention belongs to the field of medicinal chemistry and relates to improvement of a preparation method of an important ezetimibe internmediate (4S)-3-[5-(4-fluorophenyl)-1,5-dioxo amyl]-4-phenyl-2- oxazolidinone I. According to the improved method, L-phenylglycine, p-fluorobenzoylbutanoic acid are used as raw materials and are subjected to three steps of reaction to obtain the target intermediate (4S)-3-[5-(4-fluorophenyl)-1,5-dioxo amyl]-4-phenyl-2- oxazolidinone I. The preparation method disclosed by the invention is simple to operate, low in consumption, low in raw material cost and simple and easy in post-treatment and therefore is suitable for industrial production.

The invention belongs to the field of two-dimensional composite materials, and particularly relates to a graphene / molybdenum disulfide composite material and a liquid phase preparation method thereof.The structure of the composite material is a graphene microchip with the surface coated with molybdenum disulfide nanosheets. The specific preparation method comprises the following steps: firstly, dissolving ammonium tetrathiomolybdate and graphene powder into deionized water; transferring the mixed solution into a reaction container, and carrying out a hydrothermal reaction at high temperature;and finally, centrifuging and washing to obtain a reaction product. The band gap width of the molybdenum disulfide is regulated and controlled by changing the layer number of the molybdenum disulfide; so that light with different wavelengths can be absorbed, the spectral response range of a photoelectric device manufactured based on the composite material can be greatly expanded, and meanwhile, the sensitivity of the photoelectric device manufactured based on the composite material can be greatly expanded by utilizing the property of high carrier mobility of graphene.

The invention provides a chelating agent having a multidentate aminocarboxylic-type dimer, a preparation method and an application thereof, and a separation medium therewith. The structure of the chelating agent is represented as the formula (A). The chelating agent has strong chelating capability, is easy to prepare, and can be used for producing a novel separation medium with the multidentate aminocarboxylic-type dimer as a ligand. The invention also provides a novel separation medium with the multidentate aminocarboxylic-type dimer as the ligand, and a preparation method and an application thereof, wherein the novel separation medium is produced by modifying a stationary phase with the chelating agent having the multidentate aminocarboxylic-type dimer. The synthesis method is simple. The separation medium has dual functions of ion exchange chromatography and metal-chelating chromatography and can significantly improve stability of an IMAC column.

The invention relates to cyclopropyl substituted allyl alcohol and an asymmetric synthesis method thereof. The method comprises the following steps: by taking monosulfonyl chiral diamine and a complex of metals ruthenium, rhodium and iridium as a catalyst, carrying out an asymmetric transfer hydrogenation reaction, thereby obtaining the cyclopropyl substituted allyl alcohol. The method is mild in reaction conditions, simple and convenient to operate, readily available in raw materials, wide in substrate application range and high in enantioselectivity and has important application prospects in the aspect of synthesizing a psoriasis treatment drug calcipotriol.

The invention relates to a method for preparing octafluoro-substituted phthalocyanine. According to the method, easily available 4,5-dichlorophthalic acid serving as a raw material is subjected to five-step reactions, namely acetic anhydride dehydration, aniline imidization, potassium fluoride fluorination, hydrolysis and one-step condensation to obtain a target product, namely an octafluoro-substituted phthalocyanine compound. The method has the advantages of low raw material cost, mild reaction condition, safe experiment operation, simple post-treatment, relatively high target product yield, high purity and the like. A novel method is provided to preparation for synthesizing octafluoro-substituted phthalocyanine compounds, synthesis researches of octafluoro-substituted phthalocyanine compounds are promoted, and more possibility is provided to application of the octafluoro-substituted phthalocyanine compounds serving as semiconductor materials in researches of dye-sensitized solar cells, organic thin-film transistors and other aspects. The method can be easily industrialized, and the obtained product has high purity and stable quality.

The invention belongs to the field of radiochemical synthesis, and specifically relates to a synthesis method of the radioisotope carbon-14 labeled imidacloprid (1-(6-chloro-3-pyridyl[<14>C]methyl)-N-nitroimidazole-2-imine). The method has the following characteristics: carbon-14 labeled barium carbonate is used as the radioisotope raw material, 6-chloro-pyridine-3-[<14>C]formic acid is obtained by the reaction of an organometallic reagent and [<14>C] carbon dioxide, then 6-chloro-pyridine-3-[<14>C]formic acid is subjected to reactions of reduction, bromination and condensation to obtain the methylene carbon-14 labeled imidacloprid, and the total number of reaction steps are four. The radioisotope C-14 labeled imidacloprid prepared by the method has high specific activity and radiochemicalpurity, and can be used as a radioactive tracer for the study of metabolic residues of imidacloprid in plants and animals and the study of the environmental behavior of imidacloprid in soil and water. At the same time, the method establishes a preparation method of some synthetic blocks containing carbon-14.

The invention discloses a method for extraction and detection of phenolic acid effective components in honeysuckle medicinal materials by using beta-cyclodextrin as an adsorbent for matrix solid-phase dispersion extraction technology. The method includes: adding honeysuckle herbal powder and a beta-cyclodextrin adsorbent into a mortar to conduct grinding, taking a solid-phase extraction small column, adding a sieve plate at the bottom, filling the small column with grinded solid, then adding a sieve plate at the top, placing the filled small column on a solid-phase extraction instrument, taking an eluant and injecting it into the small column, conducting elution on the small column, using a centrifuge tube to collect eluent at the bottom, then conducting volution and centrifugation on the eluent in the centrifuge tube, and taking supernatant liquid, i.e. a honeysuckle phenolic acid effective component extracted liquid. Compared with the traditional extraction method, the method used by the invention has more concise and faster steps, saves time and labour, greatly reduces the organic solvent dosage, has remarkable extraction effect, and can effectively extract phenolic acid components in honeysuckle.

The present invention provides a hazardous material solid oxidation property detection apparatus and a method for detecting the hazardous material solid oxidation property by using the detection apparatus. The hazardous material solid oxidation property detection apparatus comprises a lifting rod, a metal wire ignition line fixed on the lifting rod, a heating controller of the metal wire ignition line, a lifting rod controller for controlling the lifting of the lifting rod, a sample production device for making a detected sample form a certain shape, and a heat resistance plate for placing the detected sample. With the hazardous material solid oxidation property detection apparatus of the present invention, the oxidation property of the hazardous material solid to be detected can be scientifically, efficiently and accurately determined, the selective suitable packages can be classified, the experiment operation is safe, and the personnel health of the experiment operator can not be hazarded.

The invention relates to an integral device for preparing oxidized graphene and a preparation method of the oxidized graphene. A jacket reactor of the integral device is arranged on a magnetic stirrer, and an ultrasonic signal generator is arranged on the upper portion of the jacket reactor; an inlet tube and an outlet tube are arranged on the outer jacket of the jacket reactor, a low-temperature cooling water circulation system and a circulating oil bath system are respectively connected to the inlet tube through corresponding outlet pipelines, a cooling water outlet switching valve is arranged on the outlet pipeline of the low-temperature cooling water circulation system, and a heating-oil outlet switching valve is arranged on the outlet pipeline of the circulating oil bath system; the low-temperature cooling water circulation system and the circulating oil bath system are respectively connected to the outlet tube through corresponding inlet pipelines, a backwater switching valve is arranged on the backwater pipeline of the low-temperature cooling water circulation system, and an oil return switching valve is arranged on the oil return pipeline of the circulating oil bath system. By the arrangement that ultrasound performing, stirring and oxidizing processes are performed in one reactor, repeated replacement of experimental equipment is not needed, and semi-automatic operation is realized.

The invention discloses a pressure relief device for a high-pressure constant-volume combustion bomb. The pressure relief device comprises a pressure relief connecting cavity, a hollow pressure reliefconnecting hole is formed in the pressure relief connecting cavity, a pressure relief sleeve is axially connected with the pressure relief connecting cavity, a sliding cavity and a pressure relief opening baffle are arranged in the pressure relief sleeve, the inner diameter of the pressure relief connecting hole is smaller than the outer diameter of the pressure relief opening baffle, and a sidewall of the pressure relief sleeve is further provided with a hole connected with a pressure relief pipeline. The pressure relief device is used for connecting the combustion bomb and the pressure relief cavity; the pressure relief opening baffle blocks the pressure relief connecting hole for sealing; when the fuel is combusted, the pressure of the combustion bomb is greater than that of the pressure relief sleeve; the pressure relief opening baffle is used for opening the pressure relief connecting hole for pressure relief; when the combustion bomb exhausts to reduce the pressure to be closeto the pressure of the pressure relief sleeve, the reset spring pushes the pressure relief opening baffle to close the pressure relief connecting hole, and the pressure relief device is simple in structure, convenient to manufacture and capable of better guaranteeing the test operation safety of a double-cavity combustion bomb under the high-pressure working condition and is applied to the technical field of internal combustion engines.

The invention discloses a method for determining the content of kaempferol-3-O-rutinoside in safflower, and belongs to the technical field of traditional Chinese medicine active ingredient content detection. Active ingredient, namely kaempferol-3-O-rutinoside in safflower is extracted by an organic solvent to serve as test solutions, the test solutions and a reference substance solution are determined by a high performance liquid chromatograph respectively, so that qualitative and quantitative detection of the active ingredient, namely kaempferol-3-O-rutinoside in safflower is realized, and the detection limit can reach 0.16 ug / mL; the method has the characteristics of simplicity and convenience in operation, high stability, good repeatability, strong specificity and the like, and providesa reliable detection method for subsequent qualitative and quantitative research of kaempferol-3-O-rutinoside in safflower, product quality control, evaluation index establishment and the like.

The invention discloses an experimental method and an experimental device for the environment-friendly and efficient determination of the oxygen content in the air. The method and the device are provided to overcome the defects of existing experimental methods and devices for measuring the oxygen content in the air in the prior art, such as tedious operation, non environmental protection, easily caused experiment failure, large experiment error and the like. According to the invention, a balloon is installed on a bottle plug, and a white phosphorus layer is arranged in a fuel spoon. A sodium hydroxide phenolphthalein mixed liquid layer is arranged in a beaker. The white phosphorus in the fuel spoon is ignited by a laser pen outside a gas collecting bottle for experiment purpose. Accordingto the invention, the method and the device are used for measuring the oxygen content in the air during the experiment, wherein the bottle plug of an enclosed gas collecting bottle is not required tobe disassembled for taking the fuel spoon out of the enclosed gas collecting bottle. The fuel spoon in the enclosed gas collecting bottle can be ignited from the outside of the gas collecting bottle.Especially, the condition that the bottle plug is punched away from the gas collecting bottle is avoided. The experiment change is visual. The interestingness and the ornamental value are high. Harmful substances generated by combustion in the gas collecting bottle can be removed. The experimental operation is environment-friendly, simple, convenient, efficient, accurate and safe.

The invention provides a preparation method of a grafting reinforced biochar-based heavy metal adsorption material, and relates to the technical field of biochar preparation. The preparation method of the adsorption material comprises the following steps of: (1) air-drying, grinding and sieving bagasse; (2) carrying out constant-temperature pyrolysis on the sieved bagasse, and naturally cooling to obtain bagasse biochar; (3) preparing a mixed solution system of NaOH and urea, adding the bagasse biochar, and stirring for reaction to obtain a solution system A; (4) adding halogenated hydrocarbon into the solution system A, and stirring for reaction to obtain a solution system B; and (5) adding a sodium nitrite solution into the solution system B, reacting, filtering and drying to obtain the adsorption material. The prepared nitro-grafted biochar has good adsorption capacity on heavy metals, has good adsorption effects on Cd and Sb, and can be effectively used for treatment of heavy metal-containing sewage.

The invention discloses a rubber-head burette which comprises a rubber head and a glass suction pipe, wherein the lower end of the glass suction pipe is reversely conical; and the upper end of the glass suction pipe has a calabash-shaped structure. The rubber-head burette is characterized in that scales are formed on a glass pipe body. The burette is simple in structure and easy to manufacture, can effectively avoid corrosion of reagents to the rubber head and has rough quantifying property.

The invention relates to a method for preparing octafluoro-substituted phthalocyanine. According to the method, easily available 4,5-dichlorophthalic acid serving as a raw material is subjected to five-step reactions, namely acetic anhydride dehydration, aniline imidization, potassium fluoride fluorination, hydrolysis and one-step condensation to obtain a target product, namely an octafluoro-substituted phthalocyanine compound. The method has the advantages of low raw material cost, mild reaction condition, safe experiment operation, simple post-treatment, relatively high target product yield, high purity and the like. A novel method is provided to preparation for synthesizing octafluoro-substituted phthalocyanine compounds, synthesis researches of octafluoro-substituted phthalocyanine compounds are promoted, and more possibility is provided to application of the octafluoro-substituted phthalocyanine compounds serving as semiconductor materials in researches of dye-sensitized solar cells, organic thin-film transistors and other aspects. The method can be easily industrialized, and the obtained product has high purity and stable quality.

The invention relates to a nickel metaphosphate micro-nanomaterial as well as a preparation method and an application thereof. The micro-nanomaterial has a nano sheet array structure, and the lamellar thickness of nano sheets is less than 20nm. The nickel metaphosphate micro-nanomaterial is prepared through the preparation method comprising the following steps: dissolving a soluble nickel salt and weak base molecules in a solvent to react together with carbon cloth to obtain a nickel-containing precursor / carbon cloth complex, and then performing heat treatment on the nickel-containing precursor / carbon cloth complex and a phosphate compound in an inert atmosphere to obtain the nickel metaphosphate micro-nanomaterial. Based on a structure duplication thought, the invention adopts a two-step method to achieve preparation of a micro-nanostructure and growth of a nickel metaphosphate crystal phase, respectively, the preparation of the nickel metaphosphate micro-nanomaterial with a single crystal phase is achieved, the experiment operation is simple and safe, and scale production and application can be achieved. The prepared nickel metaphosphate micro-nanomaterial has a significant pseudocapacitance characteristic, and the specific capacitance is greater than 2000F / g when the discharge current is 1A / g, so that the nickel metaphosphate micro-nanomaterial has a good potential application prospect in the aspect of electrochemical energy storage.

The invention provides a preparation method of a boron, nitrogen and sulfur ternary doped reduced graphene oxide material. The method comprises the following steps: taking graphene oxide as a base material, taking thiourea and boric acid as a reducing agent and a doping agent, preparing thiourea and boric acid into a solution, adding graphene oxide powder, and putting a suspension obtained after ultrasonic treatment into a hydrothermal synthesis reaction kettle for hydrothermal treatment; and then carrying out heat treatment on the solid-loaded substance after suction filtration and drying under the protection of inert gas to obtain the boron, nitrogen and sulfur ternary doped reduced graphene oxide material. The method is simple in step, safe in experimental operation, low in preparation cost and excellent in material performance. The boron, nitrogen and sulfur ternary doped reduced graphene oxide material obtained by the method has a larger specific surface area, and the surface defect degree and porosity of the material are further increased, so that the carrier mobility is improved, and the material can be widely applied to the field of temperature sensing.

The invention discloses a primer combination for identifying an F3 'H homologous gene. The primer combination is composed of two primers SEQNO.1 and SEQNO.2; the invention further discloses application of the primer combination in broccoli breeding. The invention relates to a molecular marker of a flavonoid 3 '-hydroxylase F3' H gene of broccoli, and a molecular marker of the flavonoid 3 '-hydroxylase F3' H gene of broccoli. The molecular marker of the F3 'H gene and a primer combination for detecting the molecular marker can be used for assisted breeding of broccoli, acceleration of the genetic improvement process of broccoli breeding and improvement of breeding selection efficiency, and have important theoretical and practical guiding significance.

The invention discloses a preparation method of an amide or ester compound, which comprises the steps of under the protection of inert gas, taking substituted carboxylic acid, an amine compound or an alcohol compound as a raw material, and reacting in an organic solvent in the presence of a phosphine oxide compound, an acyl chloride compound and organic alkali to generate the amide or ester compound. According to the preparation method, the phosphine oxide compound and the acyl chloride compound are used as condensing agents, the organic base is used as an acid-binding agent, substituted carboxylic acid and amine or alcohol react in the organic solvent to generate the amide or ester compound, the raw materials are cheap, easy to obtain, green and non-toxic, the green and environment-friendly requirements are met, the reaction rate is high, the yield is high, racemization is not prone to occurring, the atom economic utilization rate is high, the separation and post-treatment processes are simple and easy to operate, and the method is suitable for large-scale industrial production.

The invention relates to cyclopropyl substituted allyl alcohol and an asymmetric synthesis method thereof. The method comprises the following steps: by taking monosulfonyl chiral diamine and a complex of metals ruthenium, rhodium and iridium as a catalyst, carrying out an asymmetric transfer hydrogenation reaction, thereby obtaining the cyclopropyl substituted allyl alcohol. The method is mild in reaction conditions, simple and convenient to operate, readily available in raw materials, wide in substrate application range and high in enantioselectivity and has important application prospects in the aspect of synthesizing a psoriasis treatment drug calcipotriol.

Methane and chlorine substitution reaction device and method, comprising that the methane gas generation device is connected to the substitution reaction generation device through pipelines, and the substitution reaction generation device is connected to the reflux device through pipelines, and the substitution reaction generation device is provided with a chlorination device on an iron stand , the chlorination device is provided with a rubber stopper at the opening of the upper end of the large test tube, a syringe is inserted on the rubber stopper, and a partition is arranged in the middle of the upper end of the large test tube to divide the large test tube into an upper cavity and a lower cavity, and the left side of the large test tube There is a left branch pipe, the left branch pipe communicates with the upper chamber and the lower chamber body, the left three-way valve is arranged on the left branch pipe, and the right branch pipe is provided on the right side of the large test tube, and the right branch pipe communicates with the upper chamber body and the lower chamber body And the lower end of the right branch pipe stretches into the bottom of the large test tube, the right branch pipe is provided with a right three-way valve, and the large test tube is connected with the left branch pipe and the right branch pipe.