112results about How to "Many times of reuse" patented technology

The invention relates to a preparation method of a magnetic chitosan composite microsphere adsorbent, which belongs to the technical field of environmental material preparation. The preparation method comprises the following steps: firstly with FeCl3. 6H2O and FeCl2.4H2O as raw materials, preparing nano Fe3O4 by a coprecipitation process; and secondly, with glutaraldehyde as a crosslinking agent and Fe3O4, kaolin and chitosan as raw materials, synthesizing the novel magnetic chitosan composite microsphere adsorbent by an emulsification crosslinking process. The magnetic chitosan composite microsphere adsorbent is used for separating ciprofloxacin hydrochloride out of a water environment. The adsorption performance and the dynamic performance of the prepared adsorbent are researched in a static adsorption experiment. The results show that the novel magnetic chitosan composite microsphere adsorbent obtained by the method has a rapid adsorption dynamics characteristic, a high adsorption capacity and high magnetic-separation efficiency.

The invention discloses an inner-support-free double-wall locking mouth steel bushing box cofferdam construction method and an inner-support-free double-wall locking mouth steel bushing box cofferdam. Firstly, unit blocks are processed in a factory and then transported to a construction region to be spliced and formed piece by piece, the spliced unit blocks are wholly hoisted to a target pier position at the preset elevation through a large hoisting ship, then construction steps of sludge suction, tenon type locking mouth plugging, sand cushion layer filling, concrete bottom sealing, water suction, foundation clearing, steel protection barrel cutting, pile head removing, whole abutment installation and the like are performed, finally whole dismantling is performed for usage of the next pier position construction. The inner-support-free double-wall locking mouth steel bushing box cofferdam comprises a side plate, a blade foot and a joint and is characterized in that the cofferdam is of a detachable structure, a plane is partitioned into blocks, the blocks are connected in a mode that tenon type locking mouths are combined with bolts, and the inner side is not provided with an inner support. Therefore, the inner-support-free double-wall locking mouth steel bushing box cofferdam has the advantages of being small in construction difficulty, short in construction period, low in cost input, small in material consumption, high in repeated usage times, capable of being wholly recycled, safe, reliable and the like.

The invention relates to a preparation method of an arteannuin molecularly imprinted composite membrane, belonging to the technical field of environmental material preparation. The method comprises the following steps: by using a regenerated cellulose membrane as a substrate, the arteannuin as a template molecule, acrylamide (AM) as a functional monomer and ethylene glycol dimethyl acrylate (EGDMA) as a crosslinking agent, cuprous bromide and N,N',N'',N''-pentamethyldiethylenetriamine constitute a catalytic system, and an atom transfer free-radical polymerization process is utilized to prepare the arteannuin molecularly imprinted composite membrane. A static adsorption experiment is used for researching the adsorption equilibrium, dynamics and selective recognition performance of the imprinted membrane; and the result proves that the arteannuin imprinted membrane has fast adsorption dynamical properties and excellent arteannuin molecule recognition performance.

The invention relates to a preparation method of a molecularly imprinted composite membrane material, and belongs to the technical field of new materials. The specific steps are as follows: firstly, preparing carbon nanosphere gels with different concentrations as a coagulation bath, putting a preparation desired polyvinylidene fluoride membrane into the carbon nanosphere coagulation bath, and preparing a CNS@PVDF membrane through a phase inversion process; secondly, synthesizing a layer of polydopamine on the surface of the CNS@PVDF membrane to obtain a dCNS@PVDF membrane, and grafting doublebonds on the surface of the membrane through a silane coupling agent to facilitate imprinting polymerization reaction; and finally, performing imprinting polymerization reaction by using ethylene glycol dimethacrylate as a cross-linking agent, acrylamide as a functional monomer and azobisisobutyronitrile as an initiator, so that a high-performance imprinted composite membrane for separating enoxacin molecules is prepared based on molecular imprinting technology. The preparation method has the advantages of simple operation, easy implementation and higher yield, and is expected to be applied to industrial production.

The invention provides a helium mass spectrum leak detection fixture for tube plate welding seams of an evaporator. The fixture comprises a gas cylinder, mobile cores, dynamic seal rings and a static seal ring, wherein the front end of the fixture is provided with an end face flange; the end face flange is provided with a seal groove; the static seal ring is arranged in the seal groove; a group of mobile cores are connected with the gas cylinder and can coaxially and synchronously do the telescopic movement together with the gas cylinder, so that the dynamic seal rings on the mobile cores are respectively plugged up or taken off in a tube bundle hole on the surface of the tube plate of the evaporator at the same time; the end face flange and the back end of the main body of the fixture are in flexible connection by a corrugated tube; the static seal ring is tightly pressed by negative pressure generated by vacuum pumping; and the static seal ring and the seal groove both are curve-shaped according to the distribution of sealing welding seams on the surface of the tube plate and the condition of welding scars on the surface of the tube plate, and the dynamic seal rings are spindle-shaped. The fixture can quickly detect the welding quality of the sealing welding seams on the surfaces of a plurality of tube plates through the electropneumatic control over the gas cylinder and a leak detector by using an electronic control box.

The invention relates to a preparation method of attapulgite immobilized enzyme for ester exchange reaction. The preparation method of the attapulgite immobilized enzyme for the ester exchange reaction is characterized by comprising the following steps of: 1) performing acid treatment on attapulgite to obtain acid treated attapulgite; 2) performing surface chemical modification on the attapulgiteto obtain attapulgite granules with hydrophobic capacity and ion exchange double-adsorption capacity; and 3) immobilizing lipase on the surface of the attapulgite, namely putting the chemically modified attapulgite granules into a lipase solution in a ratio of (50-80)mg: 1mL, performing mechanical stirring and immobilization of the lipase, cleaning the reaction product by using distilled water after the reaction is finished, soaking the product into an organic solvent, performing centrifugal separation and performing freeze drying, and thus obtaining the attapulgite immobilized enzyme for theester exchange reaction. The attapulgite immobilized enzyme has the characteristics of low cost, high catalytic activity, good reuse performance and environment friendliness in the preparation process.

The invention relates to a preparation method and application of a GO / PVDF (Graphene Oxide / Polyvinylidene Fluoride) molecularly imprinted composite membrane for selectively separating norfloxacin, andbelongs to the technical field of new materials. The molecularly imprinted composite membrane is mainly synthesized through four steps of reactions: firstly, synthesizing graphene oxide nano-sheets;secondly, mixing graphene oxide and PVDF powder, and synthesizing a GO / PVDF mixed membrane through a phase inversion method; thirdly, coating the surface of the mixed membrane with TiO2 (Titanium Dioxide) through a hydrolysis reaction; finally, synthesizing a norfloxacin molecularly imprinted composite membrane by taking the norfloxacin, AM (Acrylamide), EGDMA (Ethylene Glycol Dimethacrylate) andAIBN (Azodiisobutyronitrile) as raw materials. The molecularly imprinted composite membrane is used for detecting residual norfloxacin in a water body. The preparation method provided by the inventionhas the characteristics of convenience in operation, easiness in implementation, higher in yield, mild in reaction conditions and the like, and is expected to be used in industrial production; in addition, static adsorption and selective permeability test results show that the molecularly imprinted composite membrane prepared by the invention has good separating performance and selectivity to thenorfloxacin.

The invention relates to the field of preparation of ethylene carbonate, and provides a catalyst for synthesizing ethylene carbonate as well as a preparation method and an application thereof. The catalyst is a composite oxide catalyst which consists of Zn and one or two of La and Co and is used for synthesizing ethylene carbonate from urea and ethylene glycol. The preparation method comprises the following steps: mixing an aqueous solution of zinc nitrate, an aqueous solution of lanthanum nitrate and an aqueous solution of cobalt nitrate in proportion, adding the obtained mixture into a precipitant urea aqueous solution, controlling the pH value of the solution, and carrying out a co-precipitation reaction to obtain the catalyst. The preparation process of the catalyst is simple and easy to implement, and the cost is low; the catalyst is high in activity, high in ethylene carbonate yield, mild in reaction condition, good in stability and easy to separate and regenerate.

The invention discloses a preparation method of nano heavy metal wastewater ion adsorption microspheres. The preparation method includes following steps: 1), preparing porous graphene microspheres; 2), modifying the surfaces of the porous graphene microspheres; 3), allowing ion exchange. The invention further discloses the nano heavy metal wastewater ion adsorption microspheres obtained by the preparation method. The surfaces of the porous graphene microspheres are modified with a triazine compound which is fixedly connected with haematoporphyrin through ionic bonds, and many amino and carboxyl on the surfaces enable the adsorption microspheres to be good in heavy metal ion adsorption effect, low in cost, high in adsorption capacity and easy in desorption.

The invention discloses a method for immobilizing fructosyl transferase by taking mesoporous molecular sieve-chitosan as a carrier, and belongs to the technical field of food enzyme engineering. The method comprises the following steps of: absorbing zymoprotein on a mesoporous molecular sieve SBA-15 which is taken as a carrier, adding chitosan and a bifunctional reagent glutaraldehyde and furtherabsorbing and cross-linking, and immobilizing the fructosyl transferase by a two-step absorption-crosslinking method so as to firmly immobilize enzyme molecules on the carrier. The recovery rate of enzyme activity of the immobilized enzyme is over 75 percent, and the thermal stability and the pH stability are superior to those of free enzyme. Compared with other immobilization methods, the invention has the advantages that: the method is easy to operate and lower in cost, and has a good immobilization effect, conditions are mild, and the enzyme molecules are difficult to leak; and the product, namely the immobilized fructosyl transferase can be applied to the production of high-purity fructooligosaccharides.

The invention relates to a preparation method of a 2,5-dyhydroxyl benzoic acid molecule blotting membrane and application of the 2,5- dyhydroxyl benzoic acid molecule blotting membrane, belongs to the technical field of material preparation and in particular relates to a method for preparing the 2,5- dyhydroxyl benzoic acid molecule blotting membrane, which adopts an alumina ceramic membrane as a substrate, adopts impurities 2,5- dihydroxy-benzoic acid (GA) in salicylic acid as a template molecule, adopts cinnamic acid as functional monomer, adopts gamma-methylacryloyloxypropyl trimethoxy silane (MPS) as a cross-linking agent, adopts ionic liquid as 1-butyl-3-methylimidazole hexafluorophosphate as a catalyst and adopts azodiisobutyronitrile (AIBN) as an initiator. Static adsorption and selective permeability experiment are used for researching adsorption equilibrium and selective recognition performance of the prepared molecule blotting membrane. According to the results, the obtained 2,5- dyhydroxyl benzoic acid molecule blotting membrane has higher adsorption capacity and excellent recognition performance of the 2,5- dyhydroxyl benzoic acid molecule.

The invention discloses a template system used for a cast-in-situ concrete floor. The template system comprises a template and multiple parallel joists. The end head of at least one joist is provided with a cantilever beam remained in the floor. The cantilever beams are steel components and protrude from the end heads of the joists, the protruded parts of the cantilever beams serve as lapping portions, and the other parts of the cantilever beams are laminated on the top surfaces of the joists and are in detachable connection with the joists through fasteners. The template system can be rapidly installed, has no vertical support, or only has a few of supports. The invention also discloses the cast-in-situ concrete floor, the multiple cantilever beams are arranged at intervals at floor supporting portions, the cantilever beams are the steel components, parts of the cantilever beams are arranged on steel beams or precast concrete beams or precast reinforced concrete shear walls which supporting the floor, and downwardly-through screw holes d and nuts are arranged near the external of a supporting seat. The cast-in-situ concrete floor is convenient to construct and is low in comprehensive cost.

The invention belongs to the technical field of high molecular materials, and relates to a composite polyolefin material, a preparation method and a use of the composite polyolefin material. The material comprises 9 parts of an outer layer flame-retardant polyolefin material and 1-4 parts of an inner layer reinforced polyolefin layer, wherein the outer layer flame-retardant polyolefin material is prepared from the following components in parts by weight: 50-80 parts of polyolefin 1, 0-30 parts of a filler 1, 16-35 parts of a fire retardant, 0-9 parts of a flame retardant synergist, 0.1-0.4 part of an antioxidant 1 and 0.1-0.4 part of a lubricating agent 1; and the inner layer reinforced polyolefin layer is prepared from the following components in parts by weight: 50-80 parts of polyolefin 2, 0-45 parts of a glass fiber, 0-30 parts of the filler 2, 0-5 parts of a graft, 0.1-0.4 part of an antioxidant 2 and 0.1-0.4 part of a lubricating agent 2. The material has the advantages of being low in cost, light in weight, good in toughness balance, changeable in size and fireproofing, and being capable of being used for a plurality of times.

The invention provides a preparation method for double-temperature-sensitive type mesoporous imprinted polymer. The preparation method comprises the following steps: step 1, preparing polymer precursor; step 2, preparing single-temperature-sensitive imprinted polymer; and step 3, preparing the double-temperature-sensitive type imprinted polymer. The preparation method is used for preparing new double-temperature-sensitive type imprinted polymer based on a mesoporous material; the material has excellent temperature sensitive characteristic, has relatively great adsorption capacity on metal ions, and has high selectivity, remarkable separation effect and many reuse times. The preparation method provides a novel method for selectively separating and enriching pollutants in environment.

The invention discloses a method for producing 1,3-diglyceride by immobilized lipase. The method comprises the following steps: mixing unsaturated long-chain fatty acid, glycerinum and the immobilizedlipase, performing stirring reaction at 25 to 40 DEG C for 1 to 12 hours, and performing post-treatment to obtain the 1,3-diglyceride, wherein the unsaturated long-chain fatty acid is at least one ofoleic acid, linoleic acid, linolenic acid, arachidonic acid and docosahexenoic acid; a mole ratio of the unsaturated long-chain fatty acid to the glycerinum is (1 to 3):1; based on the volume of a reaction system, the mass volume concentration of the immobilized lipase is 0.4 to 1 percent; the immobilized lipase is at least one of immobilized rhizopus lipase, myrhizopus lipase, lipase RM-IM, palatase 20000L lipase and Xhlip-O lipase. The method disclosed by the invention has the characteristics of high raw material conversion rate, high enzyme catalysis efficiency, a few of produced impurities, low production cost, suitability for large-scale industrial production and the like.

The invention discloses a normal temperature fast bonderite and producing method of metal plastic deformation, which is characterized by the following: the bonderite is composed of phosphoric acid, methyl ethyl ketone or acetone, eldopaque, manganese dihydrogen phosphate, calcium nitrate, zinc nitrate and water; the method comprises the following steps: mixing, emulsifying, restirring; the raw materials of bonderite is at a low price, which can be used at normal temperature. The method is easy to product, which reduces the costs of conversion.

The invention discloses a compound building template special for concreting, and relates to a building template and a manufacturing method thereof. The compound building template is prepared by bonding an aluminum alloy or zinc alloy sheet and various engineering plastics such as hard polyvinyl chloride, acrylonitrile, butadiene, styrene and the like which are taken as surface materials, and woody or bamboo plywoods or oriented strand boards which are taken as base materials of a sandwich layer by a bonding adhesive through cold pressing molding. Because of respective characteristics of the materials, raw material sources of a surface plate and a baseplate are widened, and the special requirement that the woody or bamboo plywoods or the oriented strand boards are compounded and then used in the building template can be met; and the prepared building template for the concreting has stable quality, and various indexes such as strength, elastic modulus, neatness and smoothness, acid and alkali resistance and the like meet the technical requirements of national bamboo or woody building templates.

The invention discloses a method for preparing a hydration-resistant and thermal-shock-resistant calcium oxide crucible by a dry process. The method comprises the following steps: purifying quicklime lumps, and crushing and fining the quicklime lumps with calcium oxide purity higher than 96%; mixing the quicklime fines with additives so as to form a mixture, and then, pressing the mixture into brick-shaped products; carrying out first-time temperature-controlled sintering on the brick-shaped products; crushing the sintered material obtained after first-time sintering, carrying out screening, then, carrying out proportioning proportionally, and carrying out uniform mixing so as to form clinker; loading the clinker obtained through carrying out uniform mixing in the step (4) to a crucible die, carrying out compaction on a vibrating platform, and carrying out pressing by a cold isostatic press; and putting a calcium oxide crucible green body in an electric furnace, carrying out second-time temperature-controlled sintering according to a secondary temperature-control curve, thereby obtaining a calcium oxide crucible product. The calcium oxide crucible prepared by using the method has the advantages that the hydration resistance is higher, the thermal-shock resistance is better, the sintering is denser, and the strength of the crucible is good.

The invention discloses a method for separating and purifying curcin from seeds of jatropha curcas, which comprises the following steps: firstly carrying out desalinization and buffer solution exchange on prepared curcin crude extract solution, collecting a component of a fist 280nm absorption peak after sample loading, then carrying out anion exchange chromatography on the collected component, collecting a penetrating component after the sampling loading, diluting the collected penetrating component by using buffer solution, finally carrying out cation exchange chromatography on the component solution after dilution, and collecting the component of the highest 280nm absorption peak, which is a just final curcin pure product. As the separation and purification capacity of the method is high, the method can not only improve the purity and the activity of the final product and improve the yield of the final product, but also greatly shorten the time consumption of the process cycle, andhave good process scaling-up property and low production cost, thereby providing the powerful support for research and development of various products of the curcin and deep and refined basic research based on the curcin.

The invention discloses a low-volatility monocrystalline silicon slice texturing solution which is characterized by being prepared from the following raw materials in parts by weight: 0.5-1 part of sodium hydroxide, 3-5 parts of an auxiliary agent, 0.2-0.4 part of sodium gluconate, 0.5-1 part of raffinose, 0.3-0.5 part of sodium citrate, 0.3-0.5 part of polyvinylpyrrolidone, 0.5-1 part of cocamidopropyl betaine, 0.3-0.5 part of propylene glycol alginate, 0.1-0.2 part of dimethyl silicone, and 80-100 parts of water. The texturing solution effectively improves the consistency and repeatability of a texturing technology, increases the textured surface density, thereby increasing the efficiency of solar cells and improving the quality of the product; and the texturing solution does not contain IPA and other volatile components, is beneficial to environmental protection and human health, is safe and environmentally friendly, can be reused more frequently, is strong in durability, and saves costs.

The invention provides a method for removing persistent organic pollutants in soil. The method includes the following steps that step one, soil pretreatment is performed; step two, continuous soil leaching is performed; step three, degradation of the persistent organic pollutants and heavy metal recovery are performed; and step four, pyrolysis and high-voltage pulse discharge oxidation are performed. A soil loosening agent is mixed with the soil first to avoid the aggregation of the soil due to the effects of ultrasound, leaching pressure and leaching agent components in the leaching process,and can further solubilize in synergy with the cavitation effect of ultrasound, and most of the persistent organic pollutants are removed by leaching; and then in the pyrolysis-high-voltage pulse discharge oxidation process, heating and temperature rising are performed first, the desorption and decomposition of the persistent organic pollutants can be promoted, and the high-temperature environmentimproves the use ratio of high-voltage pulse energy. The method is simple in process and mature in equipment, saves manpower and material resources, is high in removal rate of the persistent organicpollutants and heavy metal in soil and thorough in removal, and has no secondary pollution.

The invention relates to a compounded rubber overall-diaphragm filter plate. The compounded rubber overall-diaphragm filter plate comprises a steel filter plate, wherein a charging hole is formed in the center of the filter plate; a filter frame formed by welding of round steel is arranged at the peripheral edges of the front and rear surfaces of the filter plate; handles are arranged on two sides of the filter frame; a diaphragm covers the outer surfaces of the filter frame and the filter plate and is hermetically glued to the filter plate at the filter frame and the charging hole; a closed cavity is formed between the diaphragm and each of the front and rear surfaces of the filter plate; the middle and periphery of each closed cavity are closed; a compression medium inlet which is communicated with the two closed cavities is formed in one side of the filter plate; filter cloth covers the outer side of the diaphragm. The compounded rubber overall-diaphragm filter plate is high in elasticity, good in sealing performance, good in temperature resistance, good in structural strength, long in service life, unlikely to deform and break, and low in comprehensive maintenance cost; a steel framework can be repeatedly utilized.

The invention discloses a building template material. The building template material is prepared from the following components in parts by weight: 100 parts of fiberglass reinforced diamantine polyamide grafted polyolefin resin, 1 to 3 parts of a toughening agent and 1 to 3 parts of an antioxidant. A preparation method of the material collection tank comprises the following steps: adding all components in a high-speed mixer for uniformly mixing after weighing the components in proportions, feeding the mixed materials into a double-screw extruder through a feeder in accurate metering, carryingout high-speed shearing and mixing by double screws, and carrying out extruding, bracing, air-cooling, sized dicing, drying and packaging by a machine head, thus obtaining the building template material. The building template material disclosed by the invention is higher in strength, higher in toughness, excellent in ultraviolet aging resistance and flame resistance and easy in machining shaping.

The invention discloses an immobilization method of pseudomonas fluorescens lipase, and particularly relates to an immobilization method of lipase for chiral drug separation. The method comprises thefollowing steps of activating Uio-66 (Zr) MOF by using a phosphoric acid buffer solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, then adding N-hydroxysuccinimide, and then adding a phosphoric acid buffer solution of the pseudomonas fluorescens lipase into a mixed solution to carry out covalent cross-linking, thus obtaining a final product. According to the enzyme immobilization method, the lipase is immobilized by using a metal organic framework material, so that the activity and enantioselectivity of free enzyme can be maintained, and meanwhile, the lipase has stability and reusability. The immobilized enzyme is used for catalytic separation of a 2-(4-hydroxyphenyl) ethyl propionate enantiomer and a 4-methoxymandelic acid enantiomer, (R)-(-)-2-(4-hydroxyphenyl) propionic acid and (R)-4-methoxymandelic acid are prepared, and high catalytic activity and enantioselectivity are shown; and the method provides the wide prospect for the immobilized enzyme in industrial application.

The invention discloses an inner-support-free double-wall locking mouth steel bushing box cofferdam construction method and an inner-support-free double-wall locking mouth steel bushing box cofferdam. Firstly, unit blocks are processed in a factory and then transported to a construction region to be spliced and formed piece by piece, the spliced unit blocks are wholly hoisted to a target pier position at the preset elevation through a large hoisting ship, then construction steps of sludge suction, tenon type locking mouth plugging, sand cushion layer filling, concrete bottom sealing, water suction, foundation clearing, steel protection barrel cutting, pile head removing, whole abutment installation and the like are performed, finally whole dismantling is performed for usage of the next pier position construction. The inner-support-free double-wall locking mouth steel bushing box cofferdam comprises a side plate, a blade foot and a joint and is characterized in that the cofferdam is of a detachable structure, a plane is partitioned into blocks, the blocks are connected in a mode that tenon type locking mouths are combined with bolts, and the inner side is not provided with an inner support. Therefore, the inner-support-free double-wall locking mouth steel bushing box cofferdam has the advantages of being small in construction difficulty, short in construction period, low in cost input, small in material consumption, high in repeated usage times, capable of being wholly recycled, safe, reliable and the like.

The present invention relates to sisal fiber reinforced regenerated plastic building shuttering and its making process. The sisal fiber reinforced regenerated plastic building shuttering consists of laminated plastic base and sisal fabric-dry sisal leaf layer, and through hot pressing to form integral. The building shuttering is made through sorting, cleaning and pelletizing waste plastic; banburing together with stuffing to form sheet in certain size; laminating the plastic sheets and sisal fabric-dry sisal leaf layers and hot pressing. The building shuttering has high strength, high corrosion resistance, high rain water resistance, smooth surface, convenient construction and environment friendship.

The invention provides a preparation method of low molecular siloxane as well as a used catalyst and a preparation method thereof. The catalyst is a solid acid catalyst formed by a supporter loaded active component, wherein the active component at least contains platinum and zirconium oxide in a ratio of 1:(1-5). The preparation method of the low molecular siloxane comprises the following steps: by taking high hydrogen-containing silicone oil as a raw material, carrying out telomerization at the temperature of 50-110 DEG C in presence of a blocking agent and the catalyst, so that the low molecular siloxane is obtained. A novel catalyst is provided for preparation of the low molecular siloxane by adopting a telomerization process, and the catalyst has the advantages of high catalysis efficiency, specific product and high reutilization frequency.

The invention relates to an MLC blade cleaning tool. The cleaning tool comprises a cutter head, a holding handle and a bristle assembly, the cutter head is connected with one end of the holding handle, the bristle assembly is connected with the other end of the holding handle, the cutter head is a multi-section cutter head, each cutter head section is flaky, indentations are formed in the parts between the cutter head section, and the ends of the cutter head sections are oblique tangent shapes. The bristle assembly is detachably connected with the holding handle, the bristle assembly compriseshair bundles and a hair bundle installing plate which is used for inserting in the hair bundles, the end of the holding handle is provided with a groove, and the hair bundle installing plate is clamped in the groove formed in the end of the holding handle. The surface of the holding handle is provided with a frosted surface layer. Compared with the prior art, the cleaning tool has the advantagesthat the cleaning is more thorough, the front end cutter head has a section arrangement, the service life is long, the cost is saved, and the carrying is convenient.

The invention discloses a method for preparing 2,3-dihydroquinazolin-4(1H)-one and its derivatives, belonging to the technical field of organic chemical synthesis. In the preparation reaction, the molar ratio of isatoic anhydride, aromatic amine and aromatic aldehyde is 1:1:1, the molar amount of high-acidity ionic liquid catalyst is 8-12% of the isatoic anhydride used, and the reflux reaction time is 4-30min , the volume of the reaction solvent water and ethanol mixture is 3 to 6 times the molar weight of isatoic anhydride, and the reaction pressure is one atmospheric pressure. After the reaction is completed, it is cooled to room temperature and filtered with suction, and the obtained filter residue is vacuum-dried to obtain pure 2,3- Dihydroquinazolin-4(1H)-one and its derivatives. Compared with the preparation methods using other catalysts, the present invention has the characteristics of less catalyst toxicity, recyclable use, better biodegradability, green and economical whole preparation process, simple and convenient operation, and convenient industrialized large-scale production.