779 results about "Round-bottom flask" patented technology

The invention relates to a Pd / UiO-66-NH2 material having the high stability as well as a preparation method and application of the Pd / UiO-66-NH2 material. According to the Pd / UiO-66-NH2 material, a carrier is a Zr6O32 secondary structure unit and has a carrier molecular formula being [Zr6O4(OH)4(O2C-C6NH3-CO2)6], and loaded noble metal is Pd. The preparation method is as follows: weighing UiO-66-NH2 and Pd(acac), performing ultrasonic dissolving on UiO-66-NH2 and Pd(acac) in a DMF solution, simultaneously dropwise adding a Pd(acac)2DMF solution in a UiO-66-NH2 solution, mixing, performing ultrasound operation to obtain a mixed solution, transferring the mixed solution into a round-bottom flask for stirring, dropwise adding NaBH4 solution for reducing, stirring, filtering, washing, and drying to obtain powder Pd / UiO-66-NH2. Pd / UiO-66-NH2 particles related in the invention are uniform in distribution, have the sizes of about 4nm, have a high-stability carbon monoxide oxidation performance, are high in stability and are reusable.

The invention discloses a cobalt-nickel bimetallic selenide / graphene composite electrode material, and belongs to the preparation field of electrode material for supercapacitors. A manufacture methodcomprises that follow steps: adding graphene oxide (GO) into ethylene glycol solution, ultrasonic dispersing, and uniformly dispersing GO in the ethylene glycol solution; Adding polyvinylpyrrolidone(PVP), cobalt acetate tetrahydrate and nickel acetate tetrahydrate into the GO dispersion, ultrasonic dispersing and dissolving, transferring it to a round bottom flask for oil bath reaction and centrifugal washing and drying; After centrifugal washing and drying after oil bath, the product was hydrothermally selenized with sodium selenite and hydrazine hydrate to obtain Co-Ni bimetallic selenide / graphene composite electrode material. A large number of uniform size Co-Ni-Se nanosheets were uniformly loaded on graphene substrate, and the prepared electrode materials had high specific capacitance and excellent rate performance.

The invention relates to a preparation method of carbon quantum dots based on amino acid and an application of carbon quantum dots in direct detection of metal ion concentration. The method comprises the following specific steps: uniformly mixing amino acid and distilled water, rapidly adding the uniformly-mixed solution (amino acid is dissolved in distilled water) into a round-bottom flask filled with phosphoric pentoxide, rapidly plugging the bottleneck so as to obtain water-soluble carbon quantum dots, and applying the prepared carbon quantum dots in detection of metal ion concentration by a fluorescence quenching method. The synthetic method provided by the invention has a simple process, and reagents and raw materials are green and nontoxic. The prepared carbon quantum dots have characteristics of high quantum yield, strong light stability, good water-solubility and the like. Based on the quantum dots, a simple, rapid and sensitive method for metal ion quantitative detection can be established.

The invention discloses a water-dispersible HDI-TDI mixed tripolymer curing agent and a preparation method thereof. The method comprises steps as follows: (1) diisocyanate monomers and a nonionic hydrophilic modifying agent are put into a round-bottom flask under the protection of nitrogen and heated to reach 50-70 DEG C for a thermal reaction; (2) after the mixture reacts for 2-4 h, a trimerization catalyst is added, the mixture is subjected to a thermal reaction continuously, a polymerization inhibitor is added after the percentage composition of -NCO of the system reaches the target, and the mixture is subjected to the thermal reaction for 0.5-1.5 h; (3) an anion hydrophilic modifying agent is added to a tripolymer obtained in the step (2), the mixture is continuously stirred and subjected to the thermal reaction at the temperature of 60-80 DEG C, a neutralizing agent is added after the mixture reacts for 5-7 h, and the mixture is stirred uniformly, subjected to the thermal reaction for 0.5-1.5 h and discharged after being cooled. The preparation method is simple, and the prepared curing agent has the advantages of good water dispersibility, good storage stability and good film water resistance and can be applied to a water-based bi-component polyurethane coating well.

The invention discloses a preparation method of hydroxylapatite nano fibers or nano wires, comprising the following steps of: (1) adding 0.1-0.5 gram of sodium phosphates into a two-mouth round bottomed flask at 20-40 DEG C; adding 3-10 mL of 2 mol.L<-1> sodium hydroxide solutions, and mechanically stirring for 20 minutes; then adding 20 mL of oleic acid and ethanol mixing solutions with the volume ratio of 1:1, and continuously stirring for three hours; then delivering into a hydrothermal kettle; placing into an infrared insulation can at 100-180 DEG C for 5-10 hours; and (2) taking out white products inside the hydrothermal kettle; washing by distilled water for three times; washing by ethanol for three times; carrying out centrifugal separation to remove reaction residues and impurities; and finally placing the white powder products into a dry box for drying at 75 DEG C for 8 hours. The hydroxylapatite nano fibers prepared by the method have high purity, uniform grain diameter and unitary appearance.

This invention discloses a glycerol method for preparing epoxy chloropropane. The method comprises: (1) introducing dried HCl gas through 95% glycerol at 90-110 deg.C in the presence of absolute acetic acid, and reacting for 1-3 h; (2) adding the obtained dichloropropanol into a round bottom flask loaded with solid super-strong alkali catalyst, equipping condensing and drying tubes, stirring, heating to 70-90 deg.C, reacting for 3-5 h, filtering, and separating the catalyst to obtain chloropropane.

The invention discloses a method for preparing a cadmium sulfide graphite-like carbon nitride compound photocatalyst. The photocatalyst is applied to the field of carbon dioxide reduction achieved through photocatalysis. Urea is placed in a quartz crucible drying box to be dried, and then a crucible is moved to a muffle furnace to be forged; after forging ends, the crucible is naturally cooled, and a g-C3N4 catalyst is obtained; the g-C3N4 catalyst is taken and placed in a round-bottom flask containing deionized water to be stirred to obtain suspension, and then a cadmium nitrate solution and a thioacetamide solution with the molar ratio being 1:1.5 are weighed and have a constant-temperature reaction in the suspension; after the reaction, the product is cooled to room temperature, centrifuged and washed with alcohol and deionized water for many times, the product is dried, ground and put into a bag, and the CdS / g-C3N4 compound photocatalyst is obtained. Raw materials used in the method are cheap and easy to obtain, operation is easy and convenient, activity evaluation is conducted on the prepared photocatalyst, results show that the photocatalyst can effectively reduce CO2, and the activity of the photocatalyst is greatly improved compared with a pure CdS catalyst and a pure g-C3N4 catalyst.

The invention relates to the field of vitex negundo linn volatile oil, and specifically relates to a preparation method of vitex negundo linn volatile oil. The preparation method is characterized by comprising the following steps: weighing 10g of vitex negundo linn powder in a 1000mL round-bottom flask; adding 300mL of distilled water to fully immerse a material; additionally taking 50mL of normal hexane in a 500mL flask; connecting a simultaneous distillation-extraction device, wherein one end of the material maintains a micro-boiling state at about 110+ / -5 DEG C; after extraction, transferring an organic reagent to a triangular flask with a plug to obtain yellow volatile oil; as an aqueous phase and an organic phase are immiscible and are separated in a U-shaped tube and respectively flow back to the flasks on both sides, realizing the purposes of extracting, separating and enriching trace volatile and non-volatile components in a sample through a continuous and circular distillation and extraction process. By adopting the technical scheme, the extraction technology screened has the characteristics of high extraction rate and is simple to operate. The preparation method is used for preserving fresh lotus roots with excellent effect. The preparation method is conducive to improving the content of target matters.

The invention discloses an N-doped carbon-coated cobalt-nickel sulfide / graphene composite electrode material and a preparation method thereof, belonging to the field of preparation of an electrode material for super capacitors. The preparation method comprises the following processes: adding graphene oxide (GO) into an ethylene glycol solution, and performing ultrasonic dispersion to enable the GOto be uniformly dispersed in the ethylene glycol solution; adding polyvinylpyrrolidone (PVP), cobaltous acetate tetrahydrate and nickel acetate into a GO dispersion solution prepared above, after ultrasonic dispersion and dissolution, transferring to a round bottom flask to perform oil bath reaction and performing centrifugal washing and drying; enabling a product, which is dried via centrifugalwashing after oil bath, to calcine with thiourea to obtain the N-doped carbon-coated cobalt-nickel sulfide / graphene composite electrode material. According to the prepared electrode material, N-dopedcarbon is coated outside cobalt-nickel sulfide particles which have uniform sizes in microstructure, the electrode material is uniformly loaded on the substrate of graphene, and meanwhile, the electrode material has relatively high specific capacitance, excellent rate capability and cycling stability.

The invention relates to a novel process for preparing tea saponin, which integrates solvent extraction and selective separation. The steps are as follows: a. extraction and absorption: adding proper amount of the defatted cake of degreased oil-tea into a sorbitic extractor and adding macroporous absorption resin into the round bottom flask with low-concentration organic solvent, which is then heated up and back flowed; b. absorption stripping: addubg the macroporous absorption resin which has absorbed tea saponin into the solution of high-concentration organic solvent, which is heated up and back flowed in the round bottom flask to obtain the solution of tea saponin through filtering; c. obtaining the products of tea saponin by decoloring and spray drying the solution of tea saponin. The invention has the advantages that macroporous absorption resin is used to absorb tea saponin simultaneously while the tea saponin is extracted and solvent extraction and selective separation are integrated so that the manufacturing process is shortened, the energy consumption and production cost are reduced, the pollution during the process is decreased, the extracting solution is recycled and the consumption of organic solvent is reduced substantially, which can make full use of and fully develop the resource of defatted oil-tea cake.

The invention relates to a method for adjusting and controlling the diameter of a silver nanowire through the dosage of sodium chloride. The method is realized through the following measures: (1) 0.47 g of silver nitrate, 0.2 mL of water and 1mL of glycerin are mixed and dissolved at the room temperature to be prepared into a solution A; (2) 1-100 mg of sodium chloride, 2.1 g of polyvinylpyrrolidone and 59 mL of glycerin are successively added to a three-neck round-bottomed flask of 250 mL so as to be prepared into a solution B; (3) the solution A is added into the solution B, heat preservation is performed for 15 minutes to 4 hours at the temperature of 160-200 DEG C, centrifugation is performed on the reaction liquid, and lower-layer sediment is cleaned so as to obtain the silver nanowire. The method disclosed by the invention uses a polyalcohol reduction method as a basis, and the diameter of the metal silver nanowire can be conveniently adjusted and controlled by simply changing one parameter, namely the dosage of the sodium chloride; the preparation process is simple, the protection of inert gas is not needed, the reaction conditions are mild, the cost is low, and used chemical medicines are green, environmental friendly and harmfulless, so that the method is suitable for large-scale industrialized production.

The invention discloses a polymer-ionic liquid compounded clay stabilizer and a synthesis method thereof. The method comprises the following steps of copolymerizing (1-dimethylamino)-allyl phosphate containing phosphoric groups, acrylic acid and acrylamide, so as to obtain a terpolymer AA / AM / DMAAPA, preparing 100mL of aqueous solution with the mass concentration of 10,000mg / L from the AA / AM / DMAAPA, putting into a 250mL round-bottomed flask, adding 0.3g of ionic liquid [EMIM]BF4, introducing N2 for 10-20 minutes, carrying out reflux reaction for 2-4 hours at the temperature of 50 DEG C, and after the reaction is ended, carrying out reduced-pressure distillation on a reaction solution at the temperature of 50 DEG C until a gelatinous product is produced; drying the product in a baking oven with the temperature of 60 DEG C for 12 hours, thereby obtaining a polymer-ionic liquid compound AA / AM / DMAAPA-[EMIM]BF4. The polymer-ionic liquid compounded clay stabilizer synthesized by the method is intended to be applied to oilfield development and is used for inhibiting the hydrated expansion of clay.

This invention discloses a method for preparing 1, 3-propylene glycol from glycerol. The method has such advantages as high catalytic activity, mild reaction conditions, high product selectivity, high product purity, simple process. The method comprises: (1) adding 95% glycerol and 30% oxydol into a round bottom flask, setting condensing tube and drying tube, heating to 100 deg.C under stirring, and reacting for 1-3 h to obtain acetone alcohol; (2) adding acetone alcohol into a pressure reaction kettle loaded with transition oxometalate catalyst, introducing hydrogen for 4-6 h at 100-200 deg.C and 10 MPa, reacting, and rectifying to obtain 1,3-propylene glycol.

The invention discloses a preparation method of propylene hydroximic acid, wherein the temperature of the reaction is controlled by a thermostatic waterbath, a certain amount of methyl acrylate and pure water are added into a reaction vessel, the quality of the pure water is 3-4 times that of the methyl acrylate, the mixture is quickly stirred to enable the methyl acrylate to be uniformly dispersed, then hydroxylamine hydrochloride with the weight being 1.2-1.5 times that of the methyl acrylate is added into a three-opening round bottomed flask, the mixture is constantly stirred to dissolve the mixture, when the system temperature is kept stable at 20 DEG C, ionic membrane caustic soda liquid with the weight being equal to that of hydroxylamine hydrochloride,is added into the mixture by using a dripping method so as to enable the reaction to perform smoothly, meanwhile, the temperature of a reaction system is kept to be not more than 25 DEG C, low-pressure distillation is performed after the reaction to remove dissociated unreacted hydroxylamine and a by-product methyl alcohol, cooling and suction filtration are performed to remove the precipitated salinity, and the final product is a water solution of propylene hydroximic acid. The reaction is controlled to be carried out slowly by adopting a method of dripping ionic membrane caustic soda liquid, so that the dissociated hydroxylamine is prevented from being decomposed and volatilized due to rapid temperature increment, and the utilization ratio of raw materials is further improved.

The invention discloses a preparation method and application of flower-like BiOBr, belonging to the field of photocatalysts. The BiOBr has flower-like structure, and has favorable dispersity; and the petal thickness is 20-40nm, and the corolla diameter is 1-1.5 mu m. The preparation method comprises the following steps: measuring toluene, putting the toluene into a round-bottom flask, stirring at constant temperature, adding cetyl trimethylammonium bromide and oleic acid, and stirring for dissolution to obtain a solution A; measuring a certain amount of water, and adding HNO3 and Bi(NO3)3.5H2O to obtain a solution B; and while stirring, dropwisely adding the solution B into the solution A, continuing stirring for 12 hours, heating to 85 DEG C, refluxing for 12 hours, cooling the reaction product, separating, washing, and drying to obtain the flower-like BiOBr. The flower-like BiOBr can be used as a photocatalyst for degrading the organic pollutant rhodamine in water, and has favorable catalytic effect and high stability.

The invention discloses a technique for artificially synthesizing antigen of Sildenafil and derivative thereof, which comprises the following steps: generating water-soluble EDC, balancing EDC, NHS, DMF and hapten compound to room temperature, weighting EDC, NHS and hapten compound, adding the weighted sample into a clean round bottomed flask, adding DMF, dissolving and marking the generated solution as No.2 reaction solution, dissolving carrier protein in boric acid buffer solution with a ratio of 1:0.15 to 0.2 in another clean container, turning into another clean round bottomed flask and marking the solution as No.3 reaction solution, adding the No.2 reaction solution into the No.3 reaction solution, dialyzing the samples after finishing reaction, cooling and drying the samples into white flocculent products, namely the artificially synthesized antigen.

The invention provides a high-pressure-bearing free-crosslinking supermolecule composite gel leaking plugging agent and a preparation method thereof. The gel leaking plugging agent is prepared from the following ingredients in parts by weight: 83 to 90 parts of nonionic monomers, 2 to 4 parts of anionic monomers, 7 to 10 parts of cationic monomers, 1 to 3 parts of biological polysaccharide and 0.001 to 0.005 part of initiating agents. The preparation method comprises the steps that the anionic monomers are put into a three-neck round-bottom flask containing water; the pH is regulated; then, the nonionic monomers are added; after uniform stirring is performed, the initiating agents are added; heating reaction is performed under the sealed condition; then, the cationic monomers are added; reaction is continuously performed; cutting up, drying and pulverization are performed to obtain white solid powder; the biological polysaccharide and the white solid powder are uniformly mixed to obtain the target product. The high-pressure-bearing free-crosslinking supermolecule composite gel leaking plugging agent has the advantages that the leaking plugging agent prepared after dissolution in water forms a continuous space net rack structure; the pressure bearing capability and the intensity of the leaking plugging agent are improved; repeated loss cannot easily occur.

The invention discloses a preparing method and application of an Ag / AgBr / BiOCl-(001) nanometer composite material, and belong to the field of photocatalysts. The active component of the composite material is Ag / AgBr / BiOCl-(001). The material is characterized in that based on the combination of the crystal surface engineering technology and the surface plasmon resonance effect, Ag / AgBr colloidal spheres and (001)-surface-exposed BiOCl nanometer sheets (BiOCl-(001)) are composited to prepare the three-component composite photocatalyst Ag / AgBr / BiOCl-(001) is prepared. The preparing method includes the steps that ethylene glycol serves as a solvent, a certain amount of PVP and a certain amount of CTAB are weighed and put into a round-bottom flask, the mixture is fully stirred at the certain temperature to be fully dissolved, a proper amount of BiOCl-(001) is added, stirring is carried out at the constant temperature, then a proper quantity of ethylene-glycol Ag (NO3)3 solutions is slowly added, and the mixture is reacted at the temperature of 155 DEG C for 15 min, and is cooled, washed, dried to obtain the target product. The prepared Ag / AgBr / BiOCl-(001) nanometer composite material can serve as a photocatalyst to be used for the degrading reaction of methyl orange, and has the good catalytic effect and the stability.

The invention provides a metal palladium nano-material catalyst and preparation and application thereof. The catalyst is a self-assembly snowflake metal Pd nano-material for preparing phenylamine by catalytic hydrogenation of nitrobenzene. The preparation method of the catalyst comprises the following steps: dissolving palladium chloride into hydrochloric acid for fully reacting to generate palladium chlorate hydrate colloidal solution; adding benzyl alcohol to the obtained palladium chlorate hydrate to obtain benzyl alcohol solution of palladium chlorate; adding the H2PdC14-benzyl alcohol solution and directing agent PVP-benzyl alcohol solution to a round-bottom flask, adding benzyl alcohol as a solvent, transferring the flask into a microwave oven, rapidly heating while stirring rapidly until the solution is changed into dark brownish black from brown yellow, thus obtaining snowflake metal Pd nano-colloidal solution with stable PVP; and standing the colloidal solution to obtain sticky black precipitate, washing and drying the precipitate to obtain the self-assembly snowflake metal Pd nano-material. The snowflake metal Pd nano-material is mixed with the nitrobenzene and then transferred into a high-pressure reaction kettle, and then hydrogen is introduced into the kettle for hydrogenation of the nitrobenzene to obtain the phenylamine, wherein, the conversion rate of the nitrobenzene can reach up to 100%.

The invention belongs to the field of nano materials and discloses a preparation method of silicane functionalized high-water-solubility silicon dioxide nano particles and an application thereof. The preparation method comprises the following steps of: (1) hydrolyzing a silicane coupling agent with a hydrochloric acid solution with pH of 1-5, adding an acidic nano SiO2 solution and the hydrolyzedsilicane coupling agent into a round bottomed flask, stirring for 1-4 hours in a water bath at the temperature of 40-80 DEG C, extracting reaction liquid with an organic solvent and dispersing the reaction liquid into deionized water, dialyzing for one week with the deionized water to obtain a high-water-solubility functionalized nano SiO2 solution; and (2) preparing the functionalized nano SiO2 solution obtained by the step (1) into a solution with the mass fraction of 5-25%, mixing with vinyl monomers and a catalyst to form a uniform aqueous solution, adding an initiator, and carrying out free radical polymerization at room temperature to obtain the high-strength SiO2-based nano compound hydrogel.

The invention discloses biology base benzoxazine containing double bond active functional groups. Bisphenol (E)-1,2-bis(3-methoxy-4-hydroxyl phenyl)ethylene, primary amine compounds and formaldehyde compounds react to generate the benzoxazine. Bisphenol (E)-1,2-bis(3-methoxy-4-hydroxyl phenyl)ethylene is obtained by causing reproducible vanillin to undergo Mcmurry coupling reaction. The method for preparing benzoxazine comprises the steps of adding bisphenol (E)-1,2-bis(3-methoxy-4-hydroxyl phenyl)ethylene, the primary amine compounds and the formaldehyde compounds into a round-bottom flask containing solvent benzene or toluene, performing heating reflux water diversion reaction, performing extraction and drying, and performing column chromatography isolation to obtain the product. The benzoxazine has high thermal stability and high residual carbon rate, can be used alone as a monomer or mixed with other benzoxazine monomers or phenolic resin or epoxy resin for use, and an obtained cured product is good in heat resistance and can be used for the fields of high-performance structural materials, ablation-resistant materials and electronic packaging materials.

The invention discloses a piezochromic material, a preparation method and applications thereof. The preparation method comprises the following steps: adding 3 grams of carbazole, 3.3 grams of p-bromobenzaldehyde, 3.7 grams of potassium carbonate, 0.33 gram of 18-crown-6, 0.4 gram of cuprous iodide, and 18 mL of o-dichlorobenzene into a round-bottom flask (100 mL); vacuumizing under freezing, introducing nitrogen into the round-bottom flask for three times, stirring at a temperature of 180 DEG C, carrying out reflux for 48 hours; repeatedly washing the reaction system by a hydrochloric acid solution (5%), using dichloromethane to carry out extraction for three times, using waterless magnesium sulfate to dry the product, performing rotary evaporation to remove the solvent, and finally carrying out column chromatography isolation to obtain 3.9 grams of pure product, wherein the yield is 80%.

The invention provides a method for preparing platy lanthanum hydroxide nanocrystalline through a microwave-ultrasonic method. Analytically pure lanthanum nitrate hexahydrate and polyethylene glycol are added in deionized water to obtain a solution B; a potassium hydroxide or sodium hydroxide solution is added in the solution B to form a precursor solution C; the precursor solution C is poured into a four-neck round-bottom flask, the flask is put in a microwave-ultraviolet-ultrasonic trinity synthesis reaction apparatus, microwave heating and ultrasonic combination under a temperature-time mode is selected, the precursor solution C is cooled to the room temperature naturally after reaction is finished, a product is collected through centrifugation and then washed several times by deionized water and absolute ethyl alcohol, and the product is dried to obtain the final product platy lanthanum hydroxide nanocrystalline. The method adopts a simple microwave-ultrasonic preparation process, is short in reaction time period and low in energy consumption, reaction can be finished in liquid phase in one time, and no after-treatment is needed. La(OH)3 particles made by the method are of platy structures and are large in specific surface area, good in dispersibility and excellent in performance.

The invention discloses an self-adaptive flask brush head mechanism, a flask brush and a flask cleaning device, and mainly relates to the field of laboratory instrument cleaning. The device comprisesa mounting base. A rotating central shaft is mounted on the mounting base, a first lead screw is arranged on the upper part of the middle shaft, and a rail frame is fixed on the mounting base. The rail frame is provided with a lifting frame which is slidably connected to the lifting rail, and the first thread of the first screw is fixed on the lifting frame. The bottom end of the lifting frame isconnected with a control tube through the inference bearing, and the control tube and the central axis are circumferentially limited. The bottom end of the control tube is provided with an upper brushdisc, and the bottom end of the middle shaft is provided with a lower brush disc. An elastic rod is disposed between the upper brush plate and the lower brush plate, and the elastic rod surrounds thecentral axis annular array and is provided with bristles. The device has the beneficial effects of effectively solving the cleaning problem of the round bottom flask, greatly improving the efficiencyof the brushing with and significantly improved cleaning effect. The cleanliness of the experimental vessels is guaranteed.

The invention relates to a preparation method of a WO3 / ZrO2 solid super acidic catalyst. The method comprises the following steps that a zirconium hydroxide emulsion is heated in a round-bottom flask with a condenser pipe for 1-24h; a zirconium hydroxide solution is repeatedly leached and washed till a pH value of a filtrate is 6-8 and no chlorion exists; a zirconium hydroxide filter cake is soaked in C2H5OH with the concentration of 99% in a constant-temperature drying oven; drying is conducted after C2H5OH is removed; powdery zirconium hydroxide is obtained, and ground till a particle size is less than 80 meshes; and then ammonium metatungstate serves as a raw material, and is impregnated by an equal-volume method, dried and roasted to form the WO3 / ZrO2 solid super acidic catalyst. The method has the advantages of easiness and simplicity in operation, low reaction temperature, good stability and the like; in addition, in the WO3 / ZrO2 solid super acidic catalyst prepared by the method, the proportion of a tetragonal phase of zirconium dioxide is increased; a specific surface area is increased; the activity of catalytic reaction is improved obviously; and the cost is lowered effectively.

The invention relates to an explosion limit testing device of combustible gas under a high-temperature condition. The device comprises a temperature data collection system, a heating temperature control system, and a supplied gas feeding / gas pumping and purging system. The supplied gas feeding / gas pumping and purging system comprises the following components connected in parallel: a delivering pipe of gas to be detected, an oxygen delivering pipe, an air delivering pipe, and a vacuum pump. The heating temperature control system comprises a round-bottomed flask testing chamber, a heating jacket, a temperature control thermocouple, and a heating furnace. The round-bottomed flask testing chamber is suspended in the heating furnace through an insulation supporting device. The testing device provided by the invention is a semi-closed testing device. A safety valve is provided above the flask, such that pressure can be released in time after explosion occurs, and the flask is prevented from being damaged by detonation pressure. Therefore, the explosion limit of combustible gas under high-temperature condition can be effectively measured, and temperature can be accurately controlled. An upper temperature limit can reach 800 DEG C. Also, the device is convenient to observe, such that testing accuracy is greatly improved.

The invention relates to a bis-nitrogen heterocyclic carbene bis-palladium complex and a preparation method thereof, which belong to the bis-palladium complex and a preparation method thereof. The preparation method is as follows: according to the molar ratio of 1:2.05:20, bis-imidazolium chloride salt, palladium chloride, and potassium carbonate are added into a round-bottomed flask, a condenser is added to the mouth of the flask, and an inversion plug is added to the condenser. Connect it to a double-row tube vacuum line connected with argon; react at 85°C for 18h; Wash the diatomaceous earth until no yellow liquid flows down, and collect the filtrate; use a rotary evaporator to remove dichloromethane in the collected filtrate, and remove pyridine in the collected filtrate to obtain a yellow crude product; recrystallize with dichloromethane / ether to obtain a light yellow solid , that is, the bis-palladium complex of the diazoheterocyclic carbene is obtained. The synthesis step of the invention is simple, the yield is high, and it is convenient to realize industrialization.

The invention discloses a metal doped g-C3N4 based visible light catalysis flat plate type ultra-filtration membrane and a preparation method and belongs to the technical field of membrane separation. The method comprises the following steps: adding 8.0%-20.0% (w / w) of polysulfone or polyether sulfone, 5.0%-15.0% (w / w) of pore-foaming agent, 0.05%-2.0% (w / w) of surface active agent, 0.05%-5.0% (w / w) of metal doped g.C3N4 and 58.0%-86.9% (w / w) of solvent into a three-necked round-bottom flask in a certain sequence; stirring and dissolving for 5-16 hours at 30-80 DEG C till fully dissolving; standing by and de-foaming for 8-24 hours, thereby preparing a casting membrane solution; and adopting a phase inversion method for wiping the membrane on a clean glass plate, thereby preparing the visible light catalysis flat plate type ultra-filtration membrane. The visible light catalysis flat plate type ultra-filtration membrane prepared according to the method disclosed by the invention has the advantages that the pure water flux is more than or equal to 450L / m<2>.hr.0.1MPa; the reject rate of bovine serum albumin is more than or equal to 90.00%; the degrading removal rate of fulvic acid can reach about 65% (running for 1 hour under the simulated visible light); and the antifouling property and the visible light catalysis property are excellent. The metal doped g-C3N4 based visible light catalysis flat plate type ultra-filtration membrane is especially suitable for water treatment of micro-polluted water source, pretreatment of sea water desalination and treatment and recycling of wastewater in the fields of biology, chemical industry and medicines.