70results about How to "Strong concentration" patented technology

A method for generating an auditory environment for a user may include receiving a signal representing an ambient auditory environment of the user, processing the signal using a microprocessor to identify at least one of a plurality of types of sounds in the ambient auditory environment, receiving user preferences corresponding to each of the plurality of types of sounds, modifying the signal for each type of sound in the ambient auditory environment based on the corresponding user preference, and outputting the modified signal to at least one speaker to generate the auditory environment for the user. A system may include a wearable device having speakers, microphones, and various other sensors to detect a noise context. A microprocessor processes ambient sounds and generates modified audio signals using attenuation, amplification, cancellation, and / or equalization based on user preferences associated with particular types of sounds.

The invention provides a method for preparing high-solid-content and low-viscosity core-shell structure styrene-acrylic emulsion, which comprises the following steps: firstly, preparing copolymer seed emulsion in binary particle-size distribution of styrene (St) and butyl acrylate (BA); and then, dripping mixed monomers composed of styrene (St) or butyl acrylate (BA) and acrylic acid (AA) on the basis of the semi-continuous feeding process, wherein anionic emulsion and nonionic emulsion constitute a compound emulsification system in the presence of water-soluble initiator and sodium hydrogen carbonate as buffering agent. By controlling the proportion and dripping rate of the compound emulsion in different stages and adjusting the surface coverage of latex particle emulsifier, the method of the invention is capable of preparing high-solid-content and low-viscosity stable core-shell-type poly(butyl acrylate / styrene / acrylic acid) / poly(styrene / acrylic acid) [P(BA / St / AA) / P(St / AA)] emulsion. The product is widely applicable in coatings and adhesives.

The invention relates to a preparation method of an immunoaffinity chromatography medium and an application in tetraodotoxin purification. The preparation method of an immunoaffinity chromatography medium comprises the following steps of: activating a solid-phase carrier through a cyanogen bromide method; coupling a tetraodotoxin specific antibody to the swelled activated solid-phase carrier; sealing the immunoaffinity chromatography medium; and washing the immunoaffinity chromatography medium. The method for purifying tetraodotoxin by using the immunoaffinity chromatography medium comprises the following steps of: pretreating a sample containing tetraodotoxin; preparing a tetraodotoxin immunoaffinity chromatography column; loading the sample; eluting the column; and collecting the elution liquid. The immunoaffinity chromatography medium provided by the invention has high selectivity, strong retention and concentration capability on tetraodotoxin in the sample, water-phase operation, easiness in operation and good purification effect, the immunoaffinity chromatography column can be used repeatedly, a large amount of solvent can be saved, and analysis cost and environmental pollution are reduced.

The invention discloses a device for processing dimethylamine exhaust gas and wastewater. A fan is respectively connected with a plurality of shower nozzles on the bottoms of a plurality of blowing oxidation cans; the bottom of each blowing oxidation can is externally connected with a water pump; the water pump is connected with an atomizing shower nozzle arranged in a spray tower on the upper part; the lower part of the blowing oxidation can is a dimethylamine solution cavity; the dimethylamine solution is discharged from the outlet on the top of the blowing oxidation can after being blown off by air; after the dimethylamine solution is cooled by a condenser and separated by a moisture separator, mixed gas enters a low-temperature plasma purifier to carry out purification and deodorization; and the purified air is discharged from a chimney via an induced draft fan. The device has the advantages that removal effect is above 90%, and the content of the discharged dimethylamine exhaust gas is low, thereby saving energy, reducing emission, and causing low energy consumption.

A method for purifying abamectin medicines by the special immunoaffinity chromatographic column carrying immunoaffinity adsorbent is disclosed. Said adsorbent is composed of solid carrier and its coupled abamectin polyclonal or monoclonal antibody. It features that the chromatography is used to measure the contents of abamectin, having high correctness.

The invention relates to an adjustable ventilation outlet for a motor vehicle, which has a plurality of guide vanes (20a-20e) pivotable about parallel axes (23). These guide vanes are each engaged with guide slots (32a-32e) of a channel plate (30) by means of pegs, whereby the relative orientation of the guide vanes can be changed by movement of the channel plate. Independently of this, the angular orientation of the guide vanes can advantageously be adjusted synchronously via a slide ( 15 ).

The invention discloses a liver-targeted platinum-loaded nanometer prodrug for treating liver cancers and a preparation method thereof. The liver-targeted platinum-loaded nanometer prodrug is prepared by taking sodium alginate with the good biocompatibility as a framework to be modified with glycyrrhetinic acid (GA) with a liver cancer cell targeting capacity and a tetravalent platinum compound (PtCl2(OH)2(NH3)2) through a self-assembly technique. In-vitro drug releasing and cytotoxicity tests prove that the platinum-loaded drug nanoparticles have the good blood stability and the intracellular slow-release effect and also have the tumor cell killing capacity. The nanometer prodrug is expected to be used for targeting treatment on the liver cancers and has a good application prospect in the biomedical field.

The present invention discloses a medical insurance data-based clinical pathway analysis method. The method comprises a medical insurance data cleaning step and a medical insurance data analyzing step. During the medical insurance data cleaning step, invalid hospitalization data and invalid prescription detail data are removed. Meanwhile, data are clustered based on identical disease entity numbers and identical hospital level numbers, so that a plurality of analysis units are established. During the medical insurance data analyzing step, medical insurance analysis items in the analysis unitsare subjected to empirical range analysis. The empirical range analysis is in the form of grouped empirical range analysis or non-grouped empirical range analysis, wherein the sample most aggregated distribution range of medical insurance analysis items is calculated. When the frequency sum of the most aggregated distribution range is larger than a preset frequency, the empirical range of the medical insurance analysis items is obtained. According to the invention, medical insurance data are cleaned and analyzed, and then the clinical pathway analysis is conducted based on medical insurance big data. The accuracy and the scientificity of the clinical pathway analysis are improved.

Disclosed is a health care fabric, which relates to health care fabric which is manufactured by the industrial method and contains soybean fibers and bamboo charcoal fibers. The fabric on the market is mainly divided into natural fiber fabrics and artificial fiber fabrics. The costs of the natural fiber fabrics are high, the types of chemical fiber fabrics on the market are multiple, the functions are also various, but the wearing comfort is poor and the function is unitary, the chemical fiber fabrics can not reach the requirements of the customers in function, only the wearing purpose can be satisfied, and the health care and health building can not be achieved. The product can improve the defect of the products on the market. The product components comprise: 40 to 80 parts of soybean fibers by weight and 30 to 60 parts of bamboo charcoal fibers by weight. The product is the health care fabric which can be applied in various fields.

The invention relates to the technology of beneficiation machinery, in particular to a hyperfine high-gradient magnetic separator which is suitable for deironization and extraction of non-metal minerals and beneficiation of weak magnetic minerals. The hyperfine high-gradient magnetic separator comprises a main body equipment part and a rectifying control cabinet part, and the main body equipment part comprises a main body support, a magnet yoke, a magnet exciting coil and a magnetic medium box, wherein the magnet yoke is arranged on the upper part of the main body support; the magnet exciting coil is arranged around the magnet yoke; the magnetic medium box is arranged at a gap of the centre of the inner side of the magnet yoke, and the upper part of the magnetic medium box is connected with a vibration mechanism; pipe systems for enabling ore pulps to flow in and flow out and washing water to flow in and flow out are arranged at the two sides of the exterior of the magnet yoke; the pipe systems comprise various pneumatic valves, electromagnetic valves and ball valves; the pipe systems are connected with the magnetic medium box; and the rectifying control cabinet part comprises an excitation magnet and an breakage magnet, as well as a control system, wherein the excitation magnet and the breakage magnet are used for controlling the magnet exciting coil, and the control system is used for controlling actions and resetting of each valve in the pipe system, and controlling error alarming and resetting. The invention is the most ideal non-metal deironization equipment which has the advantages of strong mine-feeding granularity, concentration and grade fluctuation adaptability, reliable work and convenient operation and maintenance.

A method for purifying alpha-zearalol and / or beta-zearalol and / or zearalone and / or alpha-zearalenol by the special immunoaffinity chromatographic column carrying immunoaffinity adsorbent is disclosed. Said adsorbent is composed of solid carrier and its coupled alpha-zearalol monoclonal antibody. It features that the chromatography is used to measure the contents of alpha-zearalol and its metabolites, having high correctness.

The invention discloses a tobacco fermentation method for improving taste of cigar. The cigar is treated by utilizing extract of natural plant, and the treatment effect is amplified through a certainprocess means, thereby changing the characteristics that the cigar is large in concentration strength, bitter in aftertaste and heavy in oral residue in nature, and the style characteristic adapted tothe demands of the oriental consumer demand is formed.

The invention discloses a multi-tower type ventilation air methane temperature swing adsorption concentration device. The multi-tower type ventilation air methane temperature swing adsorption concentration device comprises a ventilation air methane inlet pipe, a hot flue gas pipe, a sweeping gas inlet pipe, a ventilation air methane outlet pipe, a desorption gas outlet pipe, a sweeping gas outlet pipe and at least three adsorption towers, wherein a first pipe joint and a second pipe joint are formed in each adsorption tower, and a methane adsorption device is arranged between the first pipe joint and the second pipe joint in each adsorption tower. By virtue of a multi-adsorption-tower structure, the quantity of the combined adsorption towers can be selected according to the flow size of ventilation air; according to the characteristics of normal-temperature methane adsorption and high-temperature methane desorption of the methane adsorption devices, ventilation air methane can be concentrated through a temperature swing adsorption process; the methane desorption can be realized through waste heat flue gas of a subsequent heat storage oxidization device, and a system is low in energy consumption. Each adsorption tower in the device has cyclic functions of normal-temperature adsorption, heating desorption and cooling regeneration. The whole device is high in utilization rate and high in methane concentration capacity.

The invention relates to a preparation method of an adsorbent containing SnO2 / Sb2O5. According to the method, SbCl3 with a stable chemical property and low toxicity is taken as a Sb source, sodium thiosulfate pentahydrate, namely SnCl4, is utilized as a Sn source, and a SnO2 / Sb2O5 binary composite oxide is prepared. The preparation method comprises the following steps of oxidizing Sb<3+> as Sb(V) in a non-water system taking alcohol as a solvent by adopting the combination of H2O2 oxidation and ultraviolet irradiation, further carrying out hydrolytic precipitation on Sb(V) and Sb<4+> by utilizing a small amount of water introduced by utilizing H2O2 solution as a reactant, and forming a binary SnO2 / Sb2O5 composite oxide. The method provided by the invention has the advantages that the hydrolyzing speed of Sb<3+> is slow, the generation of the Sb2O3 is effectively controlled, the Sn / Sb2O5 binary composite oxide with the Sb<3+> oxygenation efficiency being 100% is obtained, the adsorbent can remove the radioactive isotope Co ions and a complex thereof and stable isotope Co ions and a complex thereof, and the adsorptive property of the SnO2 / Sb2O5 binary composite oxide and pure Sb2O5 obtained by the introduction of Sb is improved by 200 times.

The invention relates to a method for concentrating an aqueous ammonium carbamate stream, which has been formed in a process for the preparation of urea, has a pressure between 0.20 MPa and 0.9 MPa, a temperature between 35° C. and 95° C., and contains at least 25 wt. % H2O, comprising: a pressure increase step, in which the aqueous ammonium carbamate stream is increased in pressure to a pressure between 1.0 MPa and 7 MPa; a condensation step, in which the aqueous ammonium carbamate stream is contacted with a gas stream, which has been formed in a process for the preparation of melamine and which consists essentially of NH3, CO2 and optionally H2O and has a lower H2O content than the aqueous ammonium carbamate stream, the gas stream being absorbed in the aqueous ammonium carbamate stream in such a way that a concentrated ammonium carbamate stream is formed that contains between 15 and 35 wt. % H2O; a discharge step, in which the concentrated ammonium carbamate stream is separated and discharged.

The invention discloses a crawler-type inspection robot which comprises a vehicle body, a driving unit installed in the vehicle body, a monitoring module installed at the top of the vehicle body, and movement suspension systems installed on the two sides of the vehicle body, wherein the vehicle body is internally provided with a battery module and a control module. The battery module provides working voltage for the driving unit and the monitoring module through the control module. The driving unit, the battery module and the control module are all fixedly installed in the vehicle body, so that the centrality is high; a battery bin cover and a maintenance opening cover are detachable, so that replacement of batteries and maintenance of internal devices are convenient; a crawler-type movement suspension system is adopted, the structure is simple and reliable, the passing ability is high, and the application range is wide; and the robot also has the functions of monitoring, navigation, collision prevention, sound-light alarm and remote communication.

The invention aims at providing a method for synthesizing alpha-ketoglutaric acid by a biological conversion method. According to the method, L-glutamic acid is used as a substrate; in a conversion culture solution obtained from kluyveromyces marxianus ATCC36534 through being cultured via a conversion culture substrate, alpha-ketoglutaricdehydrogenase inhibitors are added; the synthesis conversion culture is performed under the oscillation conditions of 25 to 30 DEG C and 200 to 250 r / min; after the synthesis conversion culture is completed, the alpha-ketoglutaric acid is obtained through separating and purifying the synthesis conversion solution; the L-glutamic acid is converted into alpha-ketoglutaric acid by yeast cells in the growth state; the alpha-ketoglutaricdehydrogenase inhibitors are added; the further metabolism consumption is blocked, so that a great amount of alpha-ketoglutaric acid is accumulated in the culture medium; when the feeing concentration of the substrate L-glutamic acid is 50g / L, the mol conversion rate can reach 83.2 percent. The low-value L-glutamic acid is converted into high-value alpha-ketoglutaric acid; the large-scale industrial application can be realized; a production process has the advantages of short period, high conversion rate, small environment pollution and the like.

The invention discloses a method for testing wear resistance of a surface coating of a profile via a falling sand tester. The method includes the steps of adjusting tilting angle of a profile plate via a spindle of a sample support, loading a sand funnel with sand, allowing the sand to flow out of a discharge outlet of the sand funnel and perpendicularly fall in a guide tube onto the profile plate along a sand guide pin, allowing the sand to slide to a guide plate along the profile plate and enters a sand box from the guide plate, allowing the sand to continue falling until that a falling sand stress point of the profile plate is worn through, closing a throttle valve to stop sand falling, metering the weight of the sand via a weigher, and measuring the wear resistance of the surface coating of the profile plate. The method has the advantages that the wear resistance of the surface coating of the profile plate is accurately measured according to the weight of the worn-through surface coating of the profile plate, and the sand is highly concentrated; the guide tube prevents wind from affecting the sand in free falling, a lifting mechanism lifts a sand weighing mechanism to the sand funnel, and the sand in the sand weighing mechanism flows into the sand funnel for reuse.

The invention discloses a method for purifying chondroitin sulfate by utilizing immunoaffinity technology, belongs to the technical field of biological medicines, and aims at solving the problem that an alcohol method in the prior art is low in purity of purified chondroitin sulfate. The method comprises the following steps: 1) taking chondroitin sulfate as an immunogen to immunize a mouse, so as to prepare an anti-chondroitin sulfate monoclonal antibody; 2) coupling the anti-chondroitin sulfate monoclonal antibody with a solid-phase carrier, and taking the conjugate as an immunoaffinity column filling material to prepare a chondroitin sulfate immunoaffinity column; and 3) purifying chondroitin sulfate through the chondroitin sulfate immunoaffinity column. The screened-out antibody used for capturing chondroitin sulfate possesses high specificity, has extremely strong delaying and concentrating capacity on chondroitin sulfate in a sample, a chondroitin sulfate sample subjected to separation purification by using an affinity chromatography media coupled with the antibody has the advantages of high purity, good quality, environment friendliness, energy saving, short production period and the like, and the method is suitable for large-scale production and easy to popularize.

The invention belongs to the technical field of VOCs processing devices, and relates to a device and method for processing VOCs through asymmetrical single-medium barrier discharge. The device comprises a draught fan, a power supply and a box body. A flow equalizing plate, an electrode fixing plate and a discharging unit are arranged in the box body. The discharging unit is of an asymmetrical discharging electrode structure, and comprises a metal electrode and an insulating medium pipe. The metal electrode is prepared from a metal rod with threads and fins. A medium internal electrode preparedfrom a conductive material is arranged in the insulating medium pipe. Gas containing VOCs enters the device from the inlet, is equalized by the flow equalizing plate and then enters a high-density strong plasma discharging area to collide and react with high-activity particles produced by discharging for degradation, coking substances produced in the discharging process are collected by a groovein the metal electrode, and the discharging stability and the high processing effect and efficiency are kept. The device has the advantages of being long in cleaning cycle, high in VOCs processing efficiency and the like, and is suitable for processing VOCs pollution in related industries.

The invention discloses hydrogel with multiple response function and a preparation method and application thereof; the preparation method of the hydrogel comprises the steps of adding hydrogel material, acryloyl chloride and triethylamine into a solvent, and reacting under ice bath to obtain modified hydrogel material; adding diselenide-diol, acryloyl chloride and triethylamine into a solvent, reacting under ice bath to obtain modified diselenide with C-C double bond; mixing the modified hydrogel material solution with the modified diselenide solution, adding a photo-polymerization initiator, and irradiating in ultraviolet at 20-40 DEG C to generate hydrogel having multiple response function. The hydrogel material is responsive to temperature, light and redox, quick gelling can be achieved by adjusting temperature, bulk concentration, photo-polymerization initiator concentration and a light source, the hydrogel is easy to form and has excellent mechanical properties and biocompatibility, and redox responsiveness of the hydrogel helps load different drug molecules and release them effectively.

The invention provides a method and a device for safely utilizing coal bed gas, and belongs to the technical field of coal bed gas treatment. The method for safely utilizing the coal bed gas comprisesthe following steps that when the volume fraction of methane in the coal bed gas is 1.5-2%, and after being heated, the coal bed gas is mixed with preheated catalyst to carry out catalytic combustionreaction; when the volume fraction of the methane in the coal bed gas is 2-4%, the coal bed gas is mixed with the preheated catalyst to carry out catalytic combustion reaction; and when the volume fraction of the methane in the coal bed gas is 4-15%, after being diluted, the coal bed gas is mixed with the preheated catalyst to carry out catalytic combustion reaction. By adoption of the treatmentmethod, safe treatment of the coal bed gas with the volume fraction of the methane being 1.5-15% can be realized; and operation is simple and convenient, energy consumption is low, and the method is suitable for industrial production.

The invention provides a power plant desulfurization wastewater advanced treatment and resource utilization system and method. The system comprises a boiler, an air preheater, an electric dust remover, a low-temperature concentration unit, a flue gas wet desulfurization absorption tower and a chimney which are sequentially communicated through flues, the bottom of the absorption tower is communicated with a gypsum slurry dehydration unit, a water outlet of the dehydration unit is communicated with the low-temperature concentration unit, the low-temperature concentration unit is communicated with a wastewater regulating tank, and desulfurization wastewater is concentrated by the low-temperature concentration unit and enters the wastewater regulating tank, the bottom of the wastewater regulating tank is communicated with a sludge treatment unit, the wastewater regulating tank is sequentially communicated with a high-density sedimentation tank, a multi-medium filtering unit, a nanofiltration unit and an evaporative crystallization unit, and the bottom of the high-density sedimentation tank is communicated with the sludge treatment unit. The method comprises the following steps: concentrating the wet desulphurization wastewater, softening the wastewater by adjusting the pH value and a sedimentation tank, reducing the content of suspended matters and heavy metals, further filtering,evaporating and crystallizing, and recovering industrial salt and fresh water.

The invention discloses a bin type arranging robot. The bin type arranging robot comprises a bin type housing for storing and mounting a control module, a two-drive differential wheel assembly which is mounted at the bottom part of the bin type housing, universal trundles which are mounted at the bottom part of the bin type housing, and a monitoring module which is mounted on the top part of the bin type housing, wherein a battery bin in which a battery module is mounted is arranged in the bin type housing; and the battery module is used for supplying working voltage to the two-drive differential wheel assembly and the monitoring module through the control module. According to the bin type arranging robot, a bin type housing body structure is adopted, and the control module can be mountedand fixed into an empty cavity in the bin type housing, so that the integrity is high; in addition, a front bin cover and a rear bin cover are detachably downwards obliquely mounted, so that the repairing and water draining are convenient; the two-drive differential wheel assembly is adopted to realize differential driving; the universal trundles are used for assisting to realize stable running; and moreover, the bin type arranging robot has the functions such as monitoring, navigating, collision preventing, collision crossing, sounding, alarming and remote communication.

The invention discloses an immunoaffinity stir bar for adsorbing diethylstilbestrol drug, and a preparation method and an application thereof. The immunoaffinity stir bar for adsorbing diethylstilbestrol drug is composed of solid phase carrier and diethylstilbestrol murine monoclonal antibody coupled with the same, wherein the ratio of the coupling length of the solid phase carrier and coupled diethylstilbestrol DES-6B4 murine monoclonal antibody to the weight thereof is 1 cm: 2 mg. Through combining with a chromatography, an extracting method can effectively separate and condense the ingredients to be detected in a sample, the toluylene compound content detection is facilitated, the disadvantages of less information amount, low quantification precision, low physico-chemical method selectivity and the like due to using the simplex immunoassay to directly detect the sample are overcome, and the analysis mechanism complementarity between the immunological technique and conventional physical and chemical technology is reflected.

The invention discloses a preparation method of an immunoaffinity column. The immunoaffinity column is a compound affinity column which is mainly prepared from three types of immunoaffinity columns through mixed packing in a volume ratio being 1:1:1, and the three types of immunoaffinity columns are prepared from three antibodies and a coupling matrix through coupling and wet packing. The column capacity of the immunoaffinity column is 2,500 ng, the immunoaffinity column is good in purification effect and can be repeatedly used three times, and average recovery rate is 67%-107%. The compound immunoaffinity column has good specific adsorption property for at least 12 sulfonamides including sulfaquinoxaline, sulfadiazine, sulfapyridine, sulfametoxydiazine, sulfadimidine, sulfamethoxazole, sulfafurazole, sulfadimethoxypyrimidine, sulfathiazole, sulfamerazine, sodium N-sulphanilamidate and sulfamonomethoxine. The immunoaffinity column which is high in coupling rate, specific adsorption property, column capacity and recovery rate is prepared, and a sensitive, rapid and simple analysis method capable of detecting residues of the 12 sulfonamides simultaneously is provided.

The invention discloses a sectional bar surface coating abrasion resistance detecting device. The sectional bar surface coating abrasion resistance detecting device comprises a supporting frame and a sand containing hopper arranged at the upper portion of the supporting frame. The discharging port of the sand containing hopper is connected with the upper end of a guide pipe. A workpiece is arranged below the lower end of the guide pipe. By means of the structure, the sectional bar surface coating abrasion resistance detecting device has the advantages that the sectional bar surface coating abrasion resistance is accurately measured through the quality of an abrasion-through sectional bar surface coating, a sand guiding needle plays a role in guiding falling sand materials, the falling sand is centralized, and the centrality of the sand materials is high; the inclination angle of a sectional bar plate is conveniently adjusted through a rotating shaft structure, and installing of the sectional bar plate is convenient; by means of a positioning needle, it is guaranteed that during each-time sampling, the sand materials freely fall down to the height the same as the contact height of the sectional bar plate, and the error produced by different heights is reduced; the effect on the freely falling sand materials from wind power is prevented through a guide pipe; a lifting mechanism elevates a sand material weighing mechanism to the sand containing hopper, the sand materials in the sand material weighing mechanism flow into the sand containing hopper, and circular using is achieved.

The invention discloses a profile surface coating wear resistance detection mechanism, which comprises a support frame and a sand-filling funnel arranged on the upper part of the support frame. Below is the workpiece. With the above structure, the present invention has the following advantages: 1. By grinding through the quality of the surface coating of the profile, the wear resistance of the surface coating of the profile can be accurately measured, and the sand material is highly concentrated; 2. The structure of the rotating shaft is convenient for the adjustment of the inclination angle of the profile plate It is also convenient for the installation of the profile plate; 3. The function of the positioning pin is to ensure that the sand material falls freely to the same height as the contact with the profile plate each time the sample is taken, reducing the error caused by the difference in height; 4. The conduit prevents the wind force from affecting the free The falling sand produces impact; the lifting mechanism lifts the sand weighing mechanism to the sand funnel, and the sand in the sand weighing mechanism flows into the sand funnel to realize recycling.

The invention discloses a section bar surface coating abrasion resistance detection mechanism which comprises a supporting frame and a sand containing funnel arranged at the upper portion of the supporting frame. A discharging port of the sand containing funnel is connected with the upper end of a guide tube, and a workpiece is arranged under the lower end of the guide tube. By the adoption of the structure, the section bar surface coating abrasion resistance detection mechanism has the advantages that the abrasion resistance of a section bar surface coating is accurately measured by abrading through the section bar surface coating, and sand material concentricity is high; inclination angle adjustment of a section bar plate is facilitated through a rotary shaft structure, and installation of the section bar plate is also facilitated; a positioning needle is used for ensuring that the contact heights from freely dropping sand materials to the section bar plate are equal during each-time sample testing, and errors caused by height difference are decreased; the guide pipe prevents wind power from influencing the freely dropping sand materials. A lifting mechanism enables a sand material weighing mechanism to rise to the position of the sand containing funnel, and the sand materials in the sand material weighing mechanism flow into the sand material weighing mechanism to achieve circular usage.

The invention discloses a mosquito attractant and a preparation method thereof. The mosquito attractant is prepared from the following raw materials in parts by weight: 5% of a yeast fermentation product, 20% of alcohol, 0.5% of lactic acid, 5% of cane sugar, 1% of nonyl acetate, 1% of heptyl acetate, 1% of octyl acetate, 1% of ethyl butyrate and 65.5% of distilled water. By the mosquito attractant, mosquitoes are attracted by the smell emitted by the yeast fermentation product; therefore, the effect of luring the mosquitoes is achieved; the smell emitted by the attractant is enabled to have strong wine smell through the alcohol; alcohol can play a role in attracting mosquitoes; the allure to the mosquitoes is further improved; the sweating smell of a human body is simulated through the lactic acid; the smell emitted by the attractant has sweaty smell of a human body, the allure to mosquitoes is further improved, the smell emitted by the attractant has sweetness through the cane sugar,and the four ingredients of nonyl acetate, heptyl acetate, octyl acetate and ethyl butyrate are spice essence, so that the attractant can simulate flower fragrance.