94results about How to "Precise size control" patented technology

The invention belongs to the technical field of preparation of isocyanate polymerization products, and discloses a method for preparing a photosensitive polyion liquid photoelectric device through dispensing. The method comprises the following steps: firstly, preparing a photosensitive material and ionic liquid, and carrying out polymerization reaction on the photosensitive material and the ionic liquid to obtain a polyionic liquid photoelectric conversion material; and sequentially printing the first conductive layer, the polyion liquid photoelectric conversion material and the second conductive layer through a microelectronic printer to obtain the photosensitive polyion liquid photoelectric device. According to the invention, the preparation process is obviously simplified, and programmed control and batch production can be realized; and the consistency of photoelectric properties of the device is improved.

The invention discloses a composite material storage box forming mold and a manufacturing method thereof, and belongs to the technical field of composite material forming molds. An end socket connecting block, an end socket cylinder section connecting ring, a split type cylinder body assembly, a cap-shaped reinforcing rib and the like are manufactured in parallel and assembled to obtain the composite material storage box forming mold. The self-weight of the mold is greatly reduced while the outer molded surface of the combined mold is guaranteed, the mold filling and demolding processes are simplified, the end socket is left in the product after the product is formed, the strength and rigidity of the storage box are improved, and a stable connecting port can be provided.

The invention provides a continuous production method of a high-strength and high-toughness austenitic stainless steel plate with a 3D full-gradient structure, and belongs to the technical field of stainless steel plate production. According to the method, an austenitic stainless steel plate is subjected to cold rolling and cutting, the size specification and the surface quality of the austenitic stainless steel plate are controlled, and then the rolled austenitic stainless steel plate is subjected to austenitizing treatment; or the austenitic stainless steel plate is firstly subjected to hot rolling to control the size specification, then rapid cooling is conducted, and the coarse-grain single-phase austenite structure is obtained. And then, reciprocating torsional deformation is conducted on the coarse-grain single-phase austenitic stainless steel plate, on the basis that the macroscopic size specification of the coarse-grain single-phase austenitic stainless steel plate is not changed, combination of the strength and the toughness of the coarse-grain single-phase austenitic stainless steel plate is greatly improved, and finally the plate is rolled into a The size specification and the surface quality of the plate are accurately controlled by adjusting a rolling process; and meanwhile, controllable construction of a 3D full-gradient structure is achieved by regulating and controlling reciprocating torsion technological parameters, and therefore cooperation of high strength and high toughness is achieved.

The invention provides a preparation method of a Cu-based catalyst for acetalation reaction, which comprises the following steps: depositing Pt on the surface of a pretreated carbon carrier through an atomic layer deposition method, depositing a metal oxide CuOx on the surface of the metal Pt, and performing high-temperature reduction and medium-temperature oxidation treatment to obtain the Cu-based catalyst. According to the method, the size of Pt particles and the thickness of CuOx can be accurately controlled on the atomic scale. The catalyst is applied to the acetalation reaction of aldol, the size of Pt particles and the thickness of CuOx can be accurately controlled on the atomic scale in the hydrogen atmosphere, the Pt-coated CuOx core-shell structure catalyst with cuprous as the main component is obtained on the surface of the carbon carrier, and the catalyst has the catalytic performance of high acetal yield due to the stable cuprous structure. The preparation of the catalyst is simple and controllable, and the greenization of the aldol acetalation reaction process and the high efficiency of the product are realized through the catalyst.

The invention relates to the technical field of resistor manufacturing, in particular to a manufacturing process of a high-frequency and high-precision resistor device. Comprising the following steps: S1, substrate molding: molding substrate material powder into a required substrate shape through pressing or a mold, and carrying out sintering molding; s2, depositing a conductive thin film: depositing a layer of extremely thin conductive thin film on the substrate, and manufacturing resistive layers with different thicknesses by using a nickel-chromium alloy material to adapt to various resistance values; s3, photoetching and etching: generating a pattern through photoetching or laser trimming, increasing a resistance path and calibrating a resistance value to ensure that the resistance value is within a design range; s4, adjusting a resistance value; s5, surface treatment; and S6, screening and packaging. According to the method, the precision and the performance are controlled through the steps of calibrating the resistance value in the technological process, accurately controlling the resistance pattern through laser energy and accurately controlling the size of the pattern, so that the final product can meet the requirements of high frequency and high precision.

The embodiment of the invention relates to the technical field of polyamide material synthesis, and particularly discloses a dispersive micron-sized strip-shaped polyamide material as well as a preparation method and application thereof, and the dispersive micron-sized strip-shaped polyamide material comprises the following raw materials: polyamide plastic, a poor solvent and a proper amount of NaOH aqueous solution. According to the embodiment of the invention, by reasonably using the raw materials and adopting a reasonable preparation process, the shape and size of the polyamide material can be accurately controlled, and the polyamide material with specific shape and size distribution is obtained; the problem that polyamide particles with specific forms and size distribution are difficult to obtain in an existing polyamide production process is solved. Moreover, the preparation method provided by the embodiment of the invention is simple, effectively expands the development space of the polyamide material in some high-performance application fields, and has a wide market prospect.

The invention belongs to the technical field of micro-nano machining, and particularly relates to a preparation method of a diamond color center array based on a phase separation nano mask. The invention comprises two schemes. The scheme I comprises the following steps: pretreating a diamond raw material; depositing a hard mask layer on the surface of the diamond; coating an adhesion layer; coating a phase-separable patterned block copolymer or assembling high polymer materials such as biological macromolecules and the like; the diamond is subjected to annealing treatment; forming a nano mask by selectively etching the surface film layer; injecting nitrogen ions to form an NV color center array; removing the hard mask; and surface carbon impurities are removed through vacuum high-temperature annealing and acid pickling, and the high-quality color center array is obtained. The second scheme comprises a deposition step of simplifying a hard mask, and a phase-separable patterned high polymer material thick film is directly coated on the surface of the diamond raw material. By adopting two different technological processes, the preparation of the nano mask ion implantation color center array which is low in cost, high in mask precision and resolution, high in flux, extensible and large in area is realized.

The invention discloses a floating transportation towing physical model test system for yaw and deviation correction simulation, which comprises a tug power simulation system, the tug power simulation system comprises a floating transportation towing platform and a jet flow loading facility, and the main body structure of the floating transportation towing platform is composed of a fixed guide rail, a movable trailer and a power supply guide rail. The movable trailer is erected on the fixed guide rail and is driven by a motor, height-adjustable horizontal slideways are erected on cross beams on the front side and the rear side of the movable trailer, hooks with pulleys are arranged on the horizontal slideways, the hooks are connected with the floating transportation component model through traction cables, and the jet flow loading facility is carried on the movable trailer. A mechanical arm, a high-pressure plunger pump and a jet nozzle are arranged, and the jet nozzle and a water supply pipeline are connected to the tail end of the mechanical arm. The invention further discloses a test method adopting the test system. The device has the function of flexibly simulating the transverse loading of the tug, and can realize the complete similar simulation of the component response in the floating yaw process and the deviation correction process.

The invention relates to hollow silicon dioxide microspheres and a preparation method thereof.The preparation method comprises the steps that an aqueous solution of a polymer, azide salt, an initiator and an organic solvent are mixed to obtain an azide-modified polymer, and the azide-modified polymer is added into a polar solvent to obtain a solution of the azide-modified polymer; mixing alkynyl-containing silane, the azido-modified polymer solution and a click chemistry catalyst, and then adding an acid catalyst or a base catalyst to carry out hydrolytic condensation reaction, so as to obtain a core-shell structure precursor of the silicon dioxide coated polymer; and carrying out roasting treatment or solvent extraction treatment on the core-shell structure precursor to obtain the hollow silicon dioxide microspheres. The preparation method provided by the invention is simple in process, relatively low in cost and relatively high in efficiency, can effectively control the particle size, the wall thickness and the density of the prepared hollow silicon dioxide microspheres, and has a wide application prospect.

The invention relates to the technical field of precision casting, in particular to a method for controlling the wall thickness of a wax mold of a complex hollow single crystal turbine blade and the wax mold. According to the method, ceramic cores are screened by obtaining the profile size of the sections, corresponding to the wall thickness points of the wax mold, of the ceramic cores; then, positioning bosses are matched with positioning holes, the screened ceramic mold cores are placed in a wax mold for positioning, wax is injected into the wax mold, and a blade wax mold is manufactured; detecting the wall thickness of a blade wax mold and the wall thickness of a corresponding casting, and obtaining a wall thickness change value; and finally, according to the wall thickness change value, the maximum value and the minimum value of the wall thickness of each detection point of the wax mold are obtained, so that the wall thickness of the wax mold produced subsequently is accurately controlled, the casting wall thickness out-of-tolerance caused by improper wax mold wall thickness control requirements is avoided, and the casting wall thickness qualification rate is increased. The problem that in the prior art, due to shrinkage of a ceramic core, the wall thickness of a wax mold of the single-crystal turbine working blade cannot meet the process requirement is solved.

The invention relates to the technical field of semiconductor manufacturing, in particular to a pore sample with large depth, and provides a method for observing a bottom structure by preparing the pore sample through a focused ion beam (FIB). According to the method, by means of filling special resin for ion thinning into pores, introducing an improved back-cutting technology and the like, the problems of pore structure deformation and large damage of focused ion beams to the interiors of the pores during sample preparation in the prior art are solved; the method has the technical effects that the stability of the bottom structure of the pore sample can be improved, and damage to the pore structure in the thinning process is avoided.

The invention discloses a low-abrasion mesoporous zirconia ceramic for dental restoration and a preparation method thereof, the mesoporous zirconia ceramic is composed of tetragonal phase zirconia crystal particles and has a mesoporous structure, the mesoporous size is 30-50nm, and the porosity is 0.3-20%; the preparation method mainly comprises the following steps: preparing a ceramic green body by a ceramic concentrated suspension liquid curing technology and sintering the ceramic green body. According to the mesoporous zirconia ceramic disclosed by the invention, mesopores are introduced among ceramic crystal particles, and the size and content of the mesopores are accurately regulated and controlled, so that good wear resistance of the material is ensured, and meanwhile, low abrasion of the material is realized.

The invention relates to the technical field of concrete processing, and provides automatic filling equipment for concrete test block forming, which comprises a vibration base, a lifting filling mechanism and a filling mold, the filling mold is provided with a forming cavity, and the filling mold is arranged at the top of the vibration base; the lifting filling mechanism comprises a lifting unit, a material receiving platform, a driving unit, a first scraper blade and a second scraper blade, the material receiving platform is provided with a filling opening, the material receiving platform is arranged on the lifting unit, the lifting unit ascends and descends to enable the filling opening to be close to or away from the upper end opening of the forming cavity, and the driving unit is arranged on the material receiving platform; the first scraping plate and the second scraping plate are movably arranged on the material receiving platform in parallel to the same direction, a material receiving cavity is defined by the first scraping plate, the second scraping plate and the material receiving platform, and the driving unit drives the first scraping plate to move in a reciprocating mode and selectively drives the second scraping plate to move in a reciprocating mode. By means of the technical scheme, the problems that in the prior art, concrete test block manufacturing and filling are low in efficiency, uneven in quality and high in cost are solved.

The invention discloses a copper nanosheet and a preparation method and application thereof.The method comprises the steps that a surfactant and a coordination agent are added into copper salt, the copper salt is reduced into nucleuses through a reducing agent, crystal nucleuses serve as seeds for nanocrystal growth, non-flaky crystals are etched away in the oxidation etching process of an etching agent, and the copper nanosheet is obtained; and the surface of the copper nanosheet is passivated by the surfactant and the coordination agent to protect flaky seed crystals of copper, so that the copper nanosheet is obtained. According to the method, a seed crystal screening mechanism is introduced, so that a non-sheet material can be effectively etched, a sheet structure is reserved, the seed crystal concentration is regulated and controlled while the yield of the copper nanosheets is improved, and precise regulation and control of the size are further realized.

This invention discloses a cultivation experimental device for studying plant ectomycorrhizal fungal interactions. It includes a base with a petri dish on it. A protective shell is installed around the petri dish on the top of the base. A circular plate is rotatably mounted inside the protective shell. Both the circular plate and the top surface of the protective shell have two symmetrical arc-shaped ventilation openings. An adjustment component connects the circular plate and the protective shell, including a splined sleeve rotatably connected to the top of the protective shell. This invention provides a cultivation experimental device for studying plant ectomycorrhizal fungal interactions that offers high adjustment precision, effortless operation, and stability. The precise design of the ventilation opening adjustment component allows for accurate control of the opening size, meeting the oxygen requirements of different fungal species and plants. Furthermore, the threaded connection of the protective shell enhances the stability and practicality of the device, providing strong support for scientific research.

The invention discloses an all-quartz multi-component Raman signal online detection module based on multi-laser additive and subtractive manufacturing. The all-quartz multi-component Raman signal online detection module comprises a node-free negative curvature hollow-core optical fiber with side micropores, a multimode optical fiber, a single-mode optical fiber plated with a ceramic film, a semicircular micro-channel, a quartz slurry packaging layer and a quartz fixing base, a micro-scale micropore is processed on the side surface of a node-free negative-curvature hollow fiber by utilizing picosecond laser, a multimode fiber, the node-free negative-curvature hollow fiber with the side micropore and a single-mode fiber are welded into a whole, the single-mode fiber is ground into a slice by utilizing an optical fiber grinding technology, and a ceramic membrane is deposited on the end surface of the slice single-mode fiber. Picosecond laser is used for scanning the quartz fixing base layer by layer so as to process a semicircular micro-channel for placing the sensor, and CO2 laser is used for scanning, depositing and curing the quartz slurry packaging layer layer by layer so as to package the sensor. According to the invention, the to-be-detected substance is injected into the all-quartz sensor, so that on-line detection of multi-component Raman signals can be realized in high electromagnetic interference environments such as electric power and the like.

This utility model discloses an integrated chamfering and edge grinding machine, relating to the field of machining technology. It includes a conveyor frame, an edge grinding frame, a clamping assembly, a lifting mechanism, and an edge grinding assembly. In use, the conveyor motor, chamfering drive motor, clamping motor, lifting mechanism, and edge grinding motor are activated separately via a controller. First, the output shaft of the clamping motor drives the clamping drive shaft to rotate. A clamping gear, mounted on the clamping drive shaft, rotates along with it. The clamping gear meshes with the serrated teeth of a misaligned clamping rod, causing the misaligned clamping rod to move under the drive of the clamping gear, thus opening and closing the clamping jaws. When the clamping jaws are closed, they firmly clamp the part to be processed, providing stable support for the chamfering operation. After the part is clamped by the clamping jaws, the chamfering drive motor starts, and its output shaft is connected to the clamping assembly to perform the chamfering operation on the part.

The application discloses a kind of welding methods of high-strength steel shell and low-strength steel inner shell penetration pipe of jacketed pressure vessel, core step includes: precision pretreatment before welding: size and defect detection, homogenization modification and preheating are carried out to machining bevel; Sequential optimization welding: the sequence of "first inside then outside" and "sectional skip welding" is combined, and prior to pipe side (high-strength steel side) is carried out backing surfacing welding; Strict welding control: the combined process of tungsten argon arc welding backing and electrode arc welding filling is used, interlayer temperature, heat input and weld size are accurately controlled; Timely and effective post-welding treatment: high-temperature post-heat treatment is carried out immediately after welding, or according to the structure constraint degree, choose whole intermediate annealing.The application effectively decomposes and releases welding stress through systematic process combination, inhibits the generation of crack, and significantly improves the welding quality and reliability of jacketed vessel penetration pipe joint.

A dicing machine comprises a fixed base, an extrusion upper die and a dicing lower die, and the fixed base is arranged to support the dicing lower die; the dicing lower die is provided with a dicing part, and the dicing part is arranged to cut small materials into dices; the upper extrusion die is arranged to be opposite to the lower dicing die and can move relative to the lower dicing die, the upper extrusion die is provided with a handheld part and an extrusion part, and the handheld part is arranged to enable an operator to move the upper extrusion die so that the extrusion part can extrude small materials located between the upper extrusion die and the lower dicing die, and the small materials are cut into dices by the dicing part. The dicing machine provided by the utility model is simple in structural design, can improve the standardization degree of dicing, accurately control the size and granularity of dices, can improve the efficiency of dicing, is convenient to clean and use, and finally can greatly reduce the labor cost after an enterprise introduces the dicing machine at low cost.

The application discloses a preparation method of defect-induced synthesis of porous carbon nanocomposites and application thereof in supercapacitors. The method uses DHPC as a carbon base to anchor Mn3O4. A large number of intrinsic defects on the surface of the DHPC optimize the local electron density distribution and surface performance, accelerate ion kinetics, provide abundant nucleation sites, and enhance the binding activity with Mn3O4. The microwave-assisted synthesis technology is used to realize the uniform dispersion of Mn3O4 nanoparticles on the DHPC, forming a three-dimensional porous network structure. The structure not only improves the conductivity of Mn3O4, but also promotes the rapid diffusion of electrolyte ions and electron transmission, simultaneously relieves the stress damage in the charging and discharging process, and significantly improves the electrochemical performance and cycle stability of the material. Compared with the prior art, the preparation method has the advantages of simple operation, low cost, environmental friendliness and the like.

The invention belongs to the field of thermoelectric materials, and particularly relates to a preparation method of a carbon nanotube film with high thermoelectric performance. The preparation method comprises the following steps: uniformly mixing carbon nanotubes with a lignin solution, and carrying out ultrasonic dispersion to obtain a carbon nanotube dispersion liquid; centrifuging the carbon nano tube dispersion liquid until the carbon nano tubes in the carbon nano tube dispersion liquid are settled, removing supernate, dispersing in ammonia water, dispensing on a slide substrate, and drying to obtain the carbon nano tube film. According to the method, lignin is adopted to disperse the carbon nanotubes and is removed through centrifugation, the problem that the carbon nanotubes are prone to agglomeration in an aqueous solution is solved, meanwhile, the influence of non-conductive lignin on the electrical properties of the carbon nanotubes is removed, and the dispersity and thermoelectric properties of the carbon nanotubes are synergistically improved.

The present invention discloses a prefabricated vertical light-weight template for assembled box culverts and a manufacturing method and a prefabricated method for box culverts, including a base, an outer mold, a connecting rod mechanism, an inner mold, an end mold and a hydraulic support mechanism. The base is composed of two longitudinal beams, three transverse beams and two walking platforms. The outer mold is composed of four integral templates, each template is attached with a steel plate inside and welded with a diagonal brace outside. The inner mold is composed of an inner layer of grid ribs and an outer layer of inner mold steel plate. The inner mold steel plate is stamped from a whole piece of steel plate. The whole section is provided with only one joint. Two longitudinal ribs are provided at the joint of the folded section. Walking wheels are provided at the lower end of the longitudinal ribs. The assembly and disassembly of the inner mold is realized by the extension and contraction of the hydraulic support mechanism. The outer mold of the present invention adopts an integral, large-block template design, which can be driven by a connecting rod mechanism or a hydraulic system. The inner mold is driven by a full hydraulic support. The whole section is provided with only one joint. Vertical casting is adopted, and the end plates are matched for production. The finished segment has a good appearance effect.

The invention discloses a mask assembly, a preparation method and evaporation equipment, and belongs to the technical field of display. The mask assembly comprises a mask, and the mask comprises an effective mask area used for being arranged corresponding to a display area of a display substrate. The mask plate comprises an organic material layer which comprises a plurality of mask openings located in the effective mask area and arranged at intervals, and the mask openings are used for being arranged corresponding to areas to be evaporated in the display area; and the magnetic pattern layer is positioned on one side of the organic material layer and is positioned among the mask openings in the effective mask region. The mask opening precision can be improved, so that the evaporation process precision requirement of the display substrate can be met.

The invention relates to the technical field of door shunting, in particular to a door shunting covered stent, a manufacturing method and a stent system. The door body shunting covered stent comprises a stent body, the periphery of the stent body is covered with a covering part, and the covering part completely surrounds the stent body in the circumferential direction; the area, covered by the coating piece, of the stent body serves as a variable-diameter area, and the yield strength of the coating piece area corresponding to the variable-diameter area is larger than the acting force applied to the coating piece when the variable-diameter area is subjected to self-expansion. After the portal shunt covered stent is implanted into a human body, the variable-diameter area is expanded through the balloon when necessary. When the wrapping part is expanded and the expansion force is greater than the yield strength of the wrapping part, accurate expansion to the expansion size of the balloon can be realized, so that the size of the variable-diameter area is within the maximum diameter, and the expanded size can be accurately controlled.

The invention provides a device and method for generating multiple horizontal bubbles, belongs to the technical field of liquid metal experiments, and is used for improving the size consistency and release synchronism of the bubbles. The device comprises a pressure controller, a function generator, a bubble generator and a liquid metal container. Each group of bubble generators comprises a power amplifier, a loudspeaker, a gas tank, a one-way valve and a needle head; the input end of the power amplifier is connected with the function generator, the output end of the power amplifier drives the loudspeaker, the loudspeaker is arranged in the gas tank, the tail end of the loudspeaker faces the tail end of the gas tank, and the head end of the loudspeaker faces the head end of the gas tank; the head end and the tail end of the gas tank are communicated with the pressure controller, and the one-way valve exists between the head end and the pressure controller; the head end of the gas tank is connected to the bottom of the liquid metal container through a needle, and sound pulses are transmitted into the liquid metal through the needle. The device is combined with the method to realize accurate and synchronous generation of a plurality of bubbles through parallel operation, so that the controllability of an experiment is improved.

The invention belongs to the field of semiconductor materials, and discloses gallium oxide and a synthesis method thereof. The synthesis method comprises the following steps: introducing ammonia water into a gallium nitrate solution, and continuously stirring to obtain a white turbid liquid; aging the white turbid liquid, filtering and washing to obtain an intermediate product; and calcining the intermediate product to obtain solid particles which are gallium oxide. According to the synthesis method, gallium nitrate and ammonia water are used as core raw materials, additional additives and complex precursors are not needed, the impurity introduction risk can be greatly reduced, and the high purity of the product can be guaranteed by combining washing and calcining procedures; meanwhile, the process steps are simple, the operation conditions are mild and controllable, expensive special equipment is not needed, the production cost is low, the method is suitable for large-scale production, and a gallium oxide product with good dispersity and high crystallinity can be obtained after a precursor prepared through a precipitation method is calcined and crushed.

The invention relates to an experimental device and an experimental method for wet granulation of solvent type supramolecular polyurethane urea, and belongs to the technical field of new materials. The device comprises a solvent polymerization reaction device, a feed liquid conveying device, a spraying and curing device, a separation device, a drying device and a screening and collecting device, the solvent polymerization reaction device, the feed liquid conveying device, the spraying and curing device and the separation device are sequentially connected, and the drying device and the screening and collecting device are sequentially arranged on the upper side of the separation device. The spraying and curing device comprises a spraying device and a curing device, the curing device is arranged below the spraying device, the curing device is connected with a separating device, the separating device comprises a filtering system and a curing agent recovery system, and the filtering system is connected with the curing agent recovery system. The particle size and shape can be accurately controlled by adjusting parameters, high-temperature operation is avoided, environmental pollution is reduced, the consistency and mechanical performance of products are remarkably improved, and the production efficiency is improved.

The application discloses a kind of aluminum nitride as medium's capacitance loaded MEMS filter and manufacturing method, method includes: providing silicon substrate;Forming first metal layer on silicon substrate, and it is patterned;Forming dielectric layer on first metal layer and it is patterned;Silicon substrate is coated with photoresist and is patterned, carries out silicon hole etching, forms silicon via by thinning process;Forming patterned second metal layer on the front and back of silicon substrate;The first metal layer is as the lower electrode of capacitor, dielectric layer is as the dielectric layer of capacitor, and the second metal layer is the upper electrode of capacitor, filter resonator, via and back ground metal.End loaded capacitor mode can greatly reduce the volume of filter, the second metal layer is simultaneously as capacitor upper electrode, filter resonator, via and back ground metal, not in need additional process step to make resonator, reduce process step, realize the miniaturization of filter, satisfy SiP integration demand.

The application relates to a soluble silk fibroin pellet quick-freezing, separating and collecting device. The device comprises a low-temperature treatment tank, an external heat preservation tank, a feeding assembly, a separating assembly and an electric control system. The low-temperature treatment tank is nested in the external heat preservation tank and is adiabatic; the feeding assembly is arranged between a top cover plate and an adiabatic plate and comprises a material feeding pipe, a liquid nitrogen feeding pipe and a recovery pipe; a liquid drop pipe is arranged in the material pipe and is provided with a heating device arranged inside the liquid drop pipe to prevent freezing; liquid drops fall through the adiabatic plate into liquid nitrogen to be quickly frozen into small balls. The parameters of a stirring paddle can be adjusted to control the particle diameter, and a peristaltic pump and the specification of the drop pipe are used to control the size. The quick-frozen mixture flows into a separating tank through a low-temperature electromagnetic valve, small balls are intercepted by a screen, and liquid nitrogen is recycled. The electric control system is used for regulating and controlling stirring, the electromagnetic valve and heating power. The device can ensure resolubility through low shear quick freezing, the quick-frozen mixture can be freeze-dried in less than 24 hours due to the high specific surface area of the small balls, the cost is reduced through liquid nitrogen circulation, and the flux and particle diameter can be controlled through multi-parameter adjustment, so that the device is suitable for the preparation of silk fibroin and composite materials.

The utility model relates to the technical field of drip irrigation, in particular to a greening maintenance drip irrigation device which comprises a water storage tank, a first filter screen, a second filter screen, a water outlet pipe, a drip irrigation head, a stirring device, a chemical adding device and a moving device. A first filter screen and a second filter screen are respectively mounted in an inner cavity of the water storage tank from top to bottom, a user can add required fertilizer, insecticide or plant nutrient solution into the water storage tank through a chemical adding device, and a stirring device is started, so that the chemical is fully and uniformly mixed with water, and uniform nutrient distribution in the irrigation process is ensured; the multiple drip irrigation heads slowly permeate into soil at the roots of plants, each drip irrigation head is provided with an independent control valve, closing and starting can be selected according to the specific positions of different plants, the chemical adding device and the stirring device are used in cooperation, fertilization operation can be synchronously completed in the irrigation process, the labor cost is saved, and the working efficiency is improved.