50results about How to "To achieve the purpose of the experiment" patented technology

The invention discloses an experiment device for simulating retention of in-pile melts obtained by melting of a reactor core of a nuclear reactor and an experiment method. The device consists of a copper heating section, a quartz glass component and a data measurement system. According to the experiment device, a melt hard shell of the reactor core is simulated through a semispherical copper ball shell; decay heat is simulated through a spiral heating wire embedded into the semispherical shell; the inner wall surface of a lower enclosure of a pressure container is simulated through quartz glass, and therefore, a flowing heat exchange phenomenon of a narrow gap between the inner wall surface of the pressure container of the reactor and the melt hard shell can be simulated, and the influence on the retention of the in-pile melts caused by flowing of water in the narrow gap can be researched. The experiment device has the advantages of visible experiment process, high experiment precision, high safety, easiness in operation and the like. A running practice shows that the experiment device runs stably and can thoroughly meet a design requirement.

The invention provides a box beam combined bending moment test mechanism. The mechanism comprises a support substrate arranged on the ground, two groups of shaft support seats arranged on left and right ends of the substrate, left and right connection bridges respectively arranged on the two groups of shaft supports, and loading structures arranged on upper ends of the left and right connection bridges. Discs are respectively arranged on the right end of the left connection bridge and the left end of the right connection bridge. A box beam test piece is welded between the discs. The loading structures are arranged on the box beam test piece. According to the invention, combined bending moment test and ultimate strength test under the static strength condition of the box beam can be achieved; and two ends of a model test segment are connected with the connection bridges through the discs and the upper parts are connected with the loading structures, so it is ensured that bending effects are generated under pressure in different angels, demanded experiment data and experiment phenomena are acquired and an experiment objective is achieved.

The invention provides a test device for simulating a dike closure hydraulic process and a method and belongs to the field of physical model experiments of hydraulics. The test device for simulating a dike closure hydraulic process comprises a testing module, a reservoir capacity change module, a data collecting module and a control module; the testing module consists of all basic testing components; the reservoir capacity change module is externally connected to the testing module; the data collection module is supported by the testing module; the control module is used for controlling a testing process. The method of the test device for simulating a dike closure hydraulic process comprises a device preparation process, a tide level adjusting process, a testing and parameter recording process, a post-testing processing process, a working condition changing testing process, and testing completion and device arrangement. The device has the advantages of simple structure, close connection of components and high testing process efficiency and is widely applicable to many working conditions; the testing design is remarkably superior to the conventional dike closure hydraulic physical model testing design.

The invention discloses an in-situ heating chip and a manufacturing method thereof. The in-situ heating chip comprises a first substrate and a second substrate. The first substrate is manufactured byusing a silicon substrate, a silicon nitride thin film and a metal bonding layer. The second substrate is manufactured by using a silicon substrate, a silicon nitride thin film, a four-electrode system and a heating metal wire. The first substrate and the second substrate are sequentially arranged from top to bottom. The first substrate is provided with two symmetrical liquid injection ports and aviewing window. The second substrate is provided with a central viewing window. The viewing window of the first substrate and the central viewing window of the second substrate are vertically alignedand consistent in size, and are bonded by means of the metal bonding layer to realize the integrated in-situ heating chip. The invention further discloses a manufacturing method of the in-situ heating chip. The in-situ heating chip enables the user to achieve the purposes of heating the sample while observing the same, ensures the atomic-scale resolution, and obviously expands the application field of electron microscope observation by introducing a thermal field.

The invention discloses a foamed aluminum tension detection fixture which comprises a tension component, a fixture component and a tension rotating handle, wherein the tension component comprises a body and a tension clamp; a mounting hole is formed at the upper end of the body; the tension rotating handle is arranged in the mounting hole; the tension clamp is arranged at the lower end of the body; the tension clamp is of a trident type; plugholes are formed at the two ends of the fixture component; the fixture component is connected with the tension clamp by a bolt. The fixture prevents a foamed aluminum composite from influence of different material properties; during tension, when a tensile force increases continuously, no falling happens; structural damages are not caused; an experiment purpose can be reached efficiently; experimental data of tensile strength of foamed aluminum is obtained; the fixture is simple in structure and convenient to mount at the same time.

The invention discloses a staged air inlet device and method for inducing strong shock waves. The staged air inlet device comprises an expansion section, a driving section, a diaphragm clamping section and an experiment section which are sequentially connected and coaxially arranged, the expansion section communicates with the driving section through a valve, the diaphragm clamping section is arranged between the driving section and the experiment section, diaphragms for separating chambers are respectively arranged between the diaphragm clamping section and the driving section and between thediaphragm clamping section and the experiment section, the signal output end of the pressure sensor is connected to a data collector through a signal converter, the data collector is used for collecting voltage signals collected by the pressure sensor, the expansion section, the driving section, the diaphragm clamping section and the experiment section are connected to a gas conveying pipeline through valves, and an expansion gas tank used for inflating the expansion section is connected to the gas conveying pipeline. According to the invention, the use of rare resource helium can be greatlyreduced, the experiment cost is saved, and the physical boundary of shock tube high-pressure experiment measurement can be remarkably widened.

The invention discloses a donepezil synthesis method which comprises the following steps: sequentially putting 5,6-dimethoxy indanone, 1-benzyl-4-piperidine methanol, a catalyst, an alkali and a solvent into a reactor; in an argon atmosphere, performing a magnetic stirring reaction in an oil bath pot sufficiently, after the reaction is completed, performing vacuum rotation evaporation and spectrumseparation, and drying, thereby obtaining a target product. By adopting the method disclosed by the invention, the problem that a great amount of byproducts are generated as reagents are used in a conventional synthesis method is solved since the components are cheap, easy to preserve and environmental-friendly and are renewable petroleum base replaceable compounds. An NNN type pincerlike metal ruthenium (II) compound is adopted as a catalyst for catalyzing reactions in the method, the reactions are completed at one step, the method is simple and convenient to operate and high in reaction efficiency, and requirements of sustainable development of environmental-friendly chemicals are met.

The invention provides?a simulation human body model for X-ray basic characteristic experiment. The simulation human-body model includes a simulation human body profile prepared by materials such as silica gel, wherein a human body skeleton and viscera prepared by PVC plastics are arranged in the simulation human body model, an electroscope with a built-in foil sheet is arranged behind a head model on the human body model, clothing covers the human body model, and a photography pocket and a mesh bag are arranged in the rear of the clothing. The simulation human body model can be used for verifying basic X-ray characteristics in medical imaging experimental teaching; the human body model is equipment with the skeleton and viscera in the internal, and simulated skin and muscles in the external layer, and is covered with the clothing, so that required imaging effect under X-rays can be reached, basic X-ray characteristics including penetrating effect, ionization effect, fluorescent effect and photosensitive effect can be verified, and the simulation human-body model for X-ray basic characteristic experiment is helpful for realizing experimental goals.

The invention discloses an electric soldering iron heating type rapid thermal fatigue experimental device and method. The electric soldering iron heating type rapid thermal fatigue experimental devicecomprises a heating system, a refrigerating system, a cooling liquid circulating system and an electric warning counter. The heating system comprises a heating power supply and a welding mouth, a sample placing point is arranged at the side end of the welding mouth, and a first circulating time relay of heating and pause time provided with a heating power supply is connected to the heating powersupply; the refrigerating system comprises a water tank and thermal resistance, a refrigerating piece is arranged at the bottom of the water tank, and a temperature controller is arranged outside thewater tank; and the cooling liquid circulating system comprises cooling liquid filled in the water tank and a water pump connected with the water tank, a cooling liquid circulating pipe is arranged onthe water tank, the middle of the cooling liquid circulating pipe is fixedly connected with the welding mouth, and a second circulating time relay capable of setting cooling time and cooling pause time of a sample is further connected to the water pump. The electric soldering iron heating type rapid thermal fatigue experimental device and method have the advantages of small volume, low cost and high temperature rising speed.

The invention discloses an EDA teaching experimental device which comprises an FPGA (Field Programmable Gate Array) module, a buzzer module, a matrix keyboard module, a dial switch module, a display module, a serial communication module, an analog-to-digital conversion module, a digital-to-analog conversion module, a real-time clock module, a 12C memory, a motor drive module and the like. Studentscan select the total or partial modules to perform circuit design so as to achieve the experimental aim. When the circuit design is performed, hardware design ability can be exercised, and the hardware can be subjected to the same control and processing by virtue of different software and different languages. The troubleshooting ability can be further exercised in the debugging process. The students can set corresponding upper computers according to requirements, so that the practice abilities of the students can be effectively improved. Due to the arrangement of an extended interface conversion module, the FPGA module is separated from the other modules, and the FPGA chip possibly needs to be replaced or updated in the subsequent experimental process. Due to the separation arrangement, replacement and update can be facilitated, the service life of the device is prolonged, and convenience can be provided for the students in expanding other baseboards.

The invention relates to a self-balanced anti-fatigue testing platform of a large-size cantilever type bearing structure. The self-balanced anti-fatigue testing platform comprises a bearing rack and a tooling body, wherein the bearing rack is connected with a fatigue testing machine; a fixed end of a test part is mounted on the tooling body; the left end of the tooling body is mounted on the bearing rack; the right end of the tooling body is fixed on a foundation; a stressing frame on which the cantilever end of the test part is mounted is mounted at the left end of the tooling body; the stressing frame is positioned under an actuator; the stressing frame is hinged with the actuator via a linking hinge; the hinging center of the stressing frame and the actuator and the connecting center of the tooling body and the bearing rack are both at the oil cylinder axis of the actuator. As the hinging center of the platform and the connecting center of the tooling body and the bearing rack are in collineation along the oil cylinder axis of the actuator, the overall structure of the bearing rack is prevented from an additional bending moment of the load of the vertical actuator, the right end of the tooling body and the fixing end of the foundation are not affected by a vertical fatigue load when a fatigue load is exerted, and thus the safety of the foundation below the test part is protected.

The invention discloses a thermal runaway gas filtration and collection device for soft-pack lithium batteries. The device structurally comprises a steel needle driving device, a heating device, a gastransferring device, a gas collection device, a neutralizer filter device, a battery fixing device and a base supporting structure. The device is characterized in that the base supporting structure is fixedly connected with the heating device; the neutralizer filter device, the battery fixing device and the heating device sleeve sequentially and are fixed by a seal ring; the neutralizer filter device, the gas transferring device and the gas collection device are connected through a connection pipe, the steel needle driving device penetrates a neutralization filter system to fixedly connect with a steel needle, and the whole gas filtration and collection device is fixed to the corresponding position of the base supporting structure. The thermal runaway gas filtration and collection devicehas advantages that due to detachability of a case, a battery can be mounted and taken out conveniently; an explosion venting sheet on the inner wall of the case plays a role in protection in batteryexplosion; stability in thermal runaway is realized, gas filtration and adjustment are realized, and easiness in operation and popularization is achieved.

The invention discloses a gravity and friction relationship test device. The device comprises a support device installed on a stand column, a gravity device placed on a light pull sheet and a variable force device assembled on a pedestal. The support device comprises a support sheet, a light pull sheet, a bayonet and a fastening bolt. The gravity device comprises a container, a container cover and a magnet. The variable force device comprises an electromagnet, a slide rheostat, a power supply, a switch, a slip sheet and a wire. Left block needle and right block needle are symmetrically arranged on the support sheet of the support device. A container cover button, a container cover thread and a container cover hole are formed on the container cover. According to the invention, the gravity and friction relationship test device has the advantages that test purpose is achieved, the structure is simple, the effect is visual, the stability is good, the repeatability is strong, the conclusion is clear and the physical knowledge learning of students is facilitated.

The invention discloses a ribosome-RNA-removed reverse transcription primer pool, a kit and a method for removing ribosome RNA. The sequences of the reverse transcription primer pool are shown as SEQID NO: 1-8; and the kit comprises the reverse transcription primer pool. The method comprises the following steps: designing reverse transcription primers covered by different densities by utilizing the rRNA sequences shared by plants; according to the difference of rRNA sequences in RNA which needs to be removed specifically, performing specific reverse transcription to obtain cDNA sequences which are completely and reversely complementary with the target RNA; specifically digesting rRNA and cDNA of a heterozygous strand through subsequent RNase H and DNase I; and finally removing the ribosome RNA. The method can be matched with a library building kit to finally obtain a transcriptome library with high enough concentration, so that the wide application of transcriptome sequencing in the fields of basic research, clinical diagnosis, drug research and development and the like is effectively realized.

The invention discloses a steel rail milling and grinding cutter which comprises a milling cutter disc. The milling cutter disc is provided with multiple milling cutter sets, each milling cutter set is provided with two rows of milling cutters, and each row of milling cutters comprises square milling and grinding blades and arc-shaped milling and grinding blades. The square milling and grinding blades in each row of milling cutters are arranged in the axial direction of the milling cutter disc, and the square milling and grinding blades in every two rows of milling cutters are arranged in a staggered manner, so that the projections of cutting edges of the square milling and grinding blades in every two rows of milling cutters in the radial direction of the milling cutter disc form a continuous first cutting edge line. The arc-shaped milling and grinding blades in every two rows of milling cutters are arranged in the axial direction of the milling cutter disc and are mutually staggered, so that the projections of cutting edges of the arc-shaped milling and grinding blades in every two rows of milling cutters in the radial direction of the milling cutter disc form a continuous second cutting edge line. The first cutting edge lines and the second cutting edge lines are mutually continuous to form a steel rail milling and grinding line. The square milling and grinding blades and the arc-shaped milling and grinding blades are reasonably arranged, so that the contact surface with a steel rail is smoother during milling and grinding, the milling and grinding effect is good, and the blades and the rail can be well protected.

The invention provides a traditional Chinese medicine composite and a preparation method thereof. The composite is composed of, by weight, 200 parts of amomum tsao-ko, 100 parts of katsumade galangal seed, 150 parts of evodia and 100 parts of alpinia oxyphylla. The traditional Chinese medicine composite has the drug purpose for promoting perioperative period postoperative gastrointestinal function recovery.

The invention provides a laboratory fuming cupboard energy-saving lighting system. The laboratory fuming cupboard energy-saving lighting system comprises an experiment cabinet body, an experiment table arranged in the experiment cabinet body, a suction opening, a wind wheel, an electric generator, a rectifier, a storage battery and a lighting lamp, wherein the suction opening, the wind wheel, theelectric generator, the rectifier, the storage battery and the lighting lamp are arranged above the experiment table, the suction opening is formed in the center of the top of the experiment cabinet body, and is connected with a ventilation pipeline, the ventilation pipeline is externally connected with a ventilation device, the wind wheel is arranged in the suction opening, the wind wheel drivesthe electric generator to generate electricity, the electric generator is connected with the alternating-current power input end of the rectifier, the direct-current power output end of the rectifieris connected with the storage battery, the storage battery is connected with the lighting lamp, the lighting lamp comprises four lamp tubes arranged on the periphery of the upper portion of the experiment cabinet body in a surrounding manner, and a reflecting plate is arranged over the four lamp tubes. The laboratory fuming cupboard energy-saving lighting system is scientific in design, capable ofrecycling energy, and saving energy and low in experiment cost.

The invention relates to a low-water pressure sealing performance test method and system for a high-water pressure solenoid valve. The low-water pressure sealing performance test method comprises thefollowing steps: connecting the to-be-tested high-water pressure solenoid valve with a straight-through valve of a water tank through a first water pipe, connecting a needle head or a fine tube with an internal diameter of no greater than 1.5 mm through a second water pipe from a water outlet of the high-water pressure solenoid valve; injecting water into the water tank, wherein the height of thewater surface away from the straight-through valve is not lower than 70 mm and is not higher than 330 mm; opening the high-water pressure solenoid valve, opening the straight-through valve and closingthe high-water pressure solenoid valve after the water is drained to air in a pipeline between the straight-through valve and the needle head or the fine tube; after the high-water pressure solenoidvalve is opened for a first preset time, closing high-water pressure solenoid valve for a second preset time, repeatedly opening and closing the high-water pressure solenoid valve for a preset numberof times; opening and closing high-water pressure solenoid valve once and acquiring the water dripped out from the needle head or the fine tube in a closed state; measuring the volume of the water acquired from the needle head or the fine tube to judge the low-water pressure sealing performance of the high-water pressure solenoid valve and realize the low-water pressure sealing performance test.

The invention discloses a fluorescence detection device and a detection method thereof. The fluorescence detection device comprises basal bodies allowing a plurality of sample test tubes to be placed,a base provided with a photoelectrical detection system, and temperature controlling devices arranged between the base and the basal bodies, wherein the photoelectric detection system comprises an exciting light module and a fluorescence detection module, and further comprises a reciprocating optical fiber scanning mechanism arranged on the base, and the reciprocating optical fiber scanning mechanism is arranged on one side of the basal bodies; detection holes are formed in one side corresponding to the optical fiber scanning mechanism, in the basal bodies; and the reciprocating optical fiberscanning mechanism is connected with the exciting light module and the fluorescence detection module through optical fibers. The test tubes carrying sample substances to be detected are placed in thebasal bodies, and a motor drives the reciprocating optical fiber scanning mechanism to be in reciprocating movement to scan fluorescence of a detection reagent, so that improvement of exciting lightefficiency is facilitated, higher fluorescence sensitivity and higher fluorescence intensity are obtained, the fluorescence signal-to-noise ratio is increased, the temperature uniformity of a module is improved, and the cost is reduced.

The invention relates to a gas base permeation reactor, which belongs to the technical field of metallurgy. A cool water inlet and a cool water outlet are arranged on a water cooled cover of the reactor, a reducing gas inlet pipe is arranged on the bottom of a reactor main body, one end of the reducing gas inlet pipe extends into the bottom in the reactor main body, the bottom of the reactor main body is provided with a sealing material, the sealing material is connected with the bottom of a large loading sleeve, air inlet holes are formed in the lateral wall of the lower part of the large loading sleeve along the circumference direction, and at least one small sleeve for reducing mineral powder is arranged in the large loading sleeve. The reducing gas deeply permeates and enters into the rare earth concentrate powder in gaps of a multi-layer steel net, the effective contact area of the reducing gas and the rare earth concentrate powder is improved, the reaction rate is improved, and better experiment result can be completed at lower investment in very short time, so as to reach the unforeseen experiment purpose. Moreover, the complicated preparation process of rare earth metals by the metallothermic method is avoided, and the coke which is increasingly lacked and used in the rare earth oxides agglomeration reducing method is saved.

The invention relates to a method for inducing nerve cells and stem cells to differentiate by utilizing an acoustic fluid. Induced differentiation of the nerve cells and the stem cells is realized byutilizing an acoustic fluid effect generated by a micro-nano piezoelectric bulk acoustic resonator capable of generating GHz waveband hypersonic sound. By changing the input power of the resonator andthe distance between the resonator and cells, the intensity of the acoustic fluid is adjusted. The cells of the invention can realize high-efficiency differentiation without intervention of externaldrugs; under the stimulation effect of the acoustic fluid, the nerve cells and the stem cells can be differentiated within a few minutes; and, based on the micron size of the micro-nano piezoelectricbulk acoustic resonator, the action range of the generated acoustic fluid is matched with the size of the resonator, so that differentiation induction of single cells can be realized by reducing the size of the resonator and the action range of the acoustic fluid. Based on the advantage that the micro-nano piezoelectric bulk acoustic resonator is small in size and easy to integrate, the resonatoris designed and produced in an array mode; and induction of large-range cell differentiation can be achieved.

The invention discloses a pneumatic birotor-casing multifunctional test bench, which comprises a rotor test bench and a pneumatic device, wherein the rotor test bench includes a casing and high and low-pressure rotors arranged in the casing; the low-pressure rotor is composed of two parts, the two parts are connected by adopting a sleeve gear coupling, and the low-pressure rotor is provided with alow-pressure turbine disk with blades and the high-pressure rotor; there is an intermediate bearing between the low-pressure rotor and the high-pressure rotor, the high-pressure rotor is provided with a high-pressure turbine disk with blades, and the wall of the casing is provided with through holes used for installing impact and rubbing devices. The pneumatic device comprises a miniature air compressor and an air storage tank, an outlet pipeline of the air storage tank is connected with an air flow divider, and the air flow divider is divided into two pipelines for controlling the rotating speed and two pipelines for controlling the impact and rubbing. The pneumatic birotor-casing multifunctional test bench can realize various airborne rotor-casing system fault experiments and casing vibration analysis, casing multi-measuring-point signal collection and analysis and the like under multi-point impact and rubbing of a shaft and a disk.

The invention belongs to the technical field of a teaching device and especially relates to an acceleration test device for physical mechanics learning. For the problems that an existing teaching device is single in function and is not convenient for multiple adjustment and conversion, and meanwhile, extra devices are needed for slope acceleration experiment, and the cost is increased and the like, the invention provides the following scheme: the acceleration test device comprises a free-fall acceleration tube and an initial acceleration tube. The free-fall acceleration tube is internally provided with a first external thread, a first sealing ring, a first inner groove and a first groove. The inner wall of the first inner groove is slidably connected with a silica gel sleeve. The inner wall of the silica gel sleeve is fixedly connected with a first magnet. The initial acceleration tube is internally provided with a second seal ring, a second inner groove, a second groove and a second external thread. The outer surface of the initial acceleration tube is fixedly connected with an elastic bearing sleeve. The device achieves an effect of free fall experiment. One experiment device cando multiple experiments, thereby improving work efficiency; the device is convenient to replace and can effectively save cost.

A primary school science buoyancy measurement experiment device disclosed by the present invention comprises a support, the left end of the top of the support is provided with an air cylinder, the inner cavity of the air cylinder is connected with a bracket through a piston, the bottom of the right side of the air cylinder is communicated with an air bag through a pipeline, and the top of the air bag is provided with a buoyancy block. A demonstration box is arranged at the right end of the top of the support, and a first supporting plate is arranged on the top of the support and located on the right side of the demonstration box. The air cylinder, the piston, the support and the air bag are arranged, air in the air cylinder can be conveyed into the air bag through a pipeline, the air bag can adjust the buoyancy of the buoyancy block in water, the requirement for buoyancy and air volume measurement experiments of people is met, meanwhile, people can pour liquid with different concentrations into the demonstration box or put solid with a small volume into water, and the demonstration box is convenient to use. Therefore, the purpose of experimenting the buoyancy of the buoyancy block in liquids with different concentrations by people is achieved, and great convenience is brought to the use of people.

The invention discloses a special acupuncture and auxiliary device for small animal unilateral acupoint selection research, which comprises a base and an acupuncture needle, two rod sleeves are arranged on a support rod mounted at the upper end of the base, and a first ball, a first ball sleeve, a second connecting rod, a rod sleeve, a second ball, a second ball sleeve and a third connecting rod are continuously mounted at the front end of the rod sleeve positioned at the lower end; the front end of the third connecting rod is provided with the upper end of a vertically-arranged sliding seat, the front surface of the sliding seat is slidably connected with a sliding plate, the lower end of the sliding plate is provided with a fourth connecting rod, the front end of the fourth connecting rod is provided with an acupuncture positioning sleeve, and the acupuncture positioning sleeve is in threaded connection with a sixth fixing bolt; compared with the prior art, the device has the advantages that after an acupuncture needle is fixed in the acupuncture positioning sleeve, the angle of the acupuncture needle can be adjusted in multiple directions by rotating the first ball sleeve and the second ball sleeve, the acupuncture position can be found, and the acupuncture needle in the acupuncture positioning sleeve is driven to stably prick into the body of a mouse on an experiment table by sliding the sliding plate downwards to complete an experiment.

A method and system for testing the low water pressure tightness of a high water pressure solenoid valve, comprising: connecting the high water pressure solenoid valve to be tested to a straight-through valve of a water tank through a first water pipe, The water outlet is connected to a needle or thin tube with an inner diameter of no more than 1.5mm through the second water pipe; water is injected into the water tank, and the height of the water surface from the straight-through valve is not less than 70mm and not higher than 330mm; open the high water pressure solenoid valve and open the straight-through valve, Close the high water pressure solenoid valve after the water flow drains the air in the pipeline between the through valve and the needle or thin tube; open the high water pressure solenoid valve for the first preset time, then close the high water pressure solenoid valve for the second Preset duration, repeatedly turn on and off the high water pressure solenoid valve for a preset number of times; then turn on and off the high water pressure solenoid valve once and collect the water dripping from the needle or thin tube in the closed state; the measurement is collected from the needle or thin tube The water volume of the water is used to judge the low water pressure sealing performance of the high water pressure solenoid valve, and realize the low water pressure tightness test.

The invention discloses a square-combination multiple-layered type experimental device for zebrafish capable of simulating crowd flow. The square-combination multiple-layered type experimental devicecomprises a partitioning plate, a hedging cabin, a light supplementing device, a water drainage pipe, a support frame, a carbon-fiber filter, a water purifying box, a base, a turbine water pump, a square fish tank, an oscillation generator, a water inlet pipe, a hemispheric bell and a spring fixer. The square-combination multiple-layered type experimental device disclosed by the invention has thebeneficial effects that a ratio of the length-width size of the square fish tank to the length-width size of a practical crowded building site is 0.08, so that the design of a model is more reasonableand is more comparative; and the zebrafish for simulating the crowd flow, raised in the square fish tank, can realize that group behavior rules of humankind can be reflected more favorably in simulation of emergency evacuation, and a water level can be controlled to about 1cm when the zebrafish is raised in the square fish tank, and action of fish school is controlled to realize strict dimensional action, superposition is avoided, and meanwhile, an influence of a reflection effect caused by depth of the water level on observation also can be reduced.