608results about How to "Achieve preparation" patented technology

The invention relates to the technical field of biology, in particular to random type difunctional carrageenase and application. The invention provides a random type difunctional carrageenase, the amino acid sequence of which is SEQ ID NO.1. The random type difunctional carrageenase can degrade iota-carrageenan and kappa-carrageenan in a random type internally tangent action mode to generate oligosaccharides with different polymerization degrees, is beneficial to research on the structure-function relationship of the carrageenan and the oligosaccharides thereof, and can be applied to the fields of food industry, chemical analysis and the like. The random type difunctional carrageenase can be applied to preparation of iota-carrageenan with different molecular weights and a series of oligosaccharides.

The invention relates to the technical field of additive manufacturing, in particular to a preparation method of a fused deposition modeling part surface metal circuit, which comprises the following steps: respectively carrying out 3D printing on a first thermoplastic material not containing an LDS additive and a second thermoplastic material containing the LDS additive, the outer surface of the formed part is the second thermoplastic material, and the interior of the formed part is the first thermoplastic material; performing laser activation on the surface of the formed part according to the metal circuit diagram; and chemical plating is conducted on the surface of the formed part subjected to laser activation, and the surface metal circuit is prepared and obtained. The preparation method of the metal circuit on the surface of the fused deposition molding part aims at solving the problem that the mechanical property is poor due to the fact that a body material contains a metal additive.

The invention discloses a method for preparing a congruent-axis structure refractory medium-entropy alloy by regulating and controlling a liquid bridge transition mode in a double-wire additive manufacturing process and an application of the congruent-axis structure refractory medium-entropy alloy. The invention belongs to the technical field of additive manufacturing. The invention aims to solve the technical problems that liquid bridge transition in the whole process cannot be realized and columnar crystals are extremely easy to form in the process of preparing the refractory medium / high-entropy alloy by adopting an electron beam double-wire additive manufacturing process at present. The method comprises the following steps: firstly, carrying out three-dimensional modeling on a target component, and carrying out slicing treatment; then liquid bridge transition is controlled by regulating and controlling a double-wire feeding strategy; and finally carrying out 3D printing. A double-wire deposition strategy and a control method thereof are adopted, the relative position of the wire and the electron beam, the relative position between the double wires and the relative position of the melting position of the double wires and the melting pool are adjusted, heat input is controlled, stable liquid bridge transition of the double wires under the condition of the constant speed or the non-constant speed is guaranteed, and the welding quality is improved. And thus, the stability of the deposition process and the congruent-equiaxed crystal structure and excellent mechanical property of a deposited part are improved.

The invention discloses a modified polylactic acid copolyester in the technical field of polymer materials. The modified polylactic acid copolyester is copolymerized by a poly-L-lactic acid prepolymer component a, a flexible degradable polyester component b and a poly-racemic lactic acid prepolymer component c through a chain extender to form a linear modified polylactic acid copolyester; the component a is prepared by ring-opening polymerization of L-lactide; the component b is a low molecular weight polyester; the component c is prepared by ring-opening polymerization of meso- / racemic-lactide; the chain extender is a polyisocyanate; the modified polylactic acid copolyester can be used to prepare a highly transparent biodegradable heat shrinkable film, the film has high heat shrinkage performance and puncture resistance, and is a degradable and environment-friendly material.

The invention provides a magnesium aluminate spinel transparent ceramic and a preparation method thereof, and the preparation method comprises the following steps: S1, raw material pretreatment, S2, vacuum hot pressing including high and low pressure circulation pressurization; and S3, hot isostatic pressing. According to the preparation method disclosed by the invention, a vacuum hot pressing process of high-low pressure circulating pressurization is combined with a step-by-step cooling and in-situ annealing process of hot isostatic pressing, so that ceramic cracking can be effectively avoided, and preparation of the large-size and high-uniformity magnesium aluminate spinel transparent ceramic is realized.

The invention discloses a method for preparing a small numerical aperture microlens array, which comprises the following steps of: preparing a silicon-based surface adhesive layer, exposing and overlay, developing, hot melting, etching and the like, setting photoresist spin-coating to be multi-layer spin-coating, enabling photoresist materials and spin-coating parameters of different adhesive layers to be different, enabling the viscosities of three layers of photoresist to be obviously distinguished, and improving the resolution of the three layers of photoresist. The factor is a key factor for influencing subsequent small numerical aperture microlens forming; circular masks with different areas are designed, precise control on the aperture of the micro lens after hot melting of the lens can be realized after overlay exposure, and the surface uniformity of the micro lens array in the silicon-based wafer is improved; the temperature and time of hot melting and baking are the key of fusing the double-layer photoresist structure to form the micro lens; the etching parameters with the etching speed higher than that of silicon are selected, the curvature radius of the microlens can be further increased, the small numerical aperture and the size of the microlens are reduced, and therefore preparation of the small numerical aperture microlens array is effectively achieved.

The invention relates to the technical field of semiconductor photoelectronics and liquid crystal materials, in particular to a vortex light laser and a preparation method thereof. The supporting structure is arranged on the laser light source; the liquid crystal structure is arranged on the supporting structure, and the liquid crystal structure is configured to convert linearly polarized light from the laser light source into circularly polarized light and further convert the circularly polarized light into vortex light. In addition, the cholesteric liquid crystal in the liquid crystal structure can change the rotation direction of the circularly polarized light under the irradiation of the ultraviolet light source, so that the topological charge number of the vortex light can be regulated and controlled. Compared with a traditional vortex light laser, the vortex light laser has the advantages of being high in conversion efficiency, low in preparation cost, high in preparation speed, capable of tuning vortex light of orbital angular momentum, capable of conducting autonomous regulation and control on emergent light under the condition that an external electric field is not introduced, and capable of improving the utilization rate of the vortex light. The preparation process is compatible with the traditional semiconductor process, the size is small, and the integration level is high.

The invention relates to the technical field of perovskite solar cell preparation, in particular to a bulk phase passivation perovskite light absorption layer, a solar cell and a preparation method, the bulk phase passivation perovskite light absorption layer is prepared by adopting a perovskite layer prefabricated liquid, the perovskite layer prefabricated liquid comprises (FA 0.95 MA0.05) 0.95 Cs0.05 Pb (I 0.95 Br0.05) 3 and m-F-PEACl, the molar concentration ratio of the (FA 0.95 MA0.05) 0.95 Cs0.05 Pb (I 0.95 Br0.05) 3 to the m-F-PEACl is 1.5: (0.1-1), m-F-PEACl and (FA < 0.95 > MA0. 05) < 0.95 > Cs0. 05Pb (I < 0.95 > Br0. 05) 3 are matched to form a bulk phase passivated perovskite layer, so that organic cations in the m-F-PEACl interact with uncoordinated lead ions or other defect sites in the (FA < 0.95 > MA0. 05) < 0.95 > Cs0. 05Pb (I < 0.95 > Br0. 05) 3 to form a stable complex or compound, the defect concentration in perovskite is reduced, comprehensive and effective passivation is realized, and the performance of the perovskite is improved. Therefore, the photoelectric property and the stability of the perovskite material are improved. The problem that comprehensive and effective passivation cannot be achieved through a perovskite thin film passivation method in the prior art is solved.

The invention provides a precise circuit packaging substrate and a manufacturing method thereof, and the method comprises the following steps: providing a substrate which comprises a core plate and a conductive metal layer at least disposed on the first surface of the core plate; forming a grain boundary buffer material layer on the surface, far away from the core plate, of the conductive metal layer, and pretreating the grain boundary buffer material layer to obtain a grain boundary buffer layer; providing an electroplating shielding layer, and forming a base circuit layer on the surface, away from the substrate, of the grain boundary buffer layer based on the electroplating shielding layer; at least one layer of wiring structure is formed on the surface, away from the substrate, of the base circuit layer, the wiring structure comprises a dielectric layer covering the exposed surface of the base circuit layer, a metal connecting layer penetrating through the dielectric layer and a conductive circuit layer located on the surface, away from the base circuit layer, of the dielectric layer, and the metal connecting layer is electrically connected with the base circuit layer and the conductive circuit layer. According to the precise circuit packaging substrate and the manufacturing method thereof, the problem of circuit separation in the process of manufacturing the precise circuit packaging substrate is avoided, and the yield of the packaging substrate is improved.

The invention provides sequoia sempervirens stem fermentation liquor and a preparation method and application thereof, and the preparation method specifically comprises the following steps: (1) crushing dried bark of sequoia sempervirens, adding inulin, a carbon source, a nitrogen source, inorganic salt and water, and sterilizing to obtain a dried bark culture medium of sequoia sempervirens; and (2) inoculating saccharomyces cerevisiae and bacillus subtilis into the sequoia sempervirens dry bark culture medium for fermentation, and then sterilizing and centrifuging to obtain sequoia sempervirens stem fermentation liquor. Experiments show that the sequoia sempervirens stem fermentation liquor prepared by the method provided by the invention is high in active ingredient content, and has various effects of resisting inflammation, relieving and resisting allergy, promoting wound healing, resisting aging and the like. The fermentation liquor prepared by the method provided by the invention can be widely applied to preparation of cosmetics with anti-aging, anti-allergy and repairing effects.

The invention discloses a multistage fine-adjustable modular coaxial capillary micro-fluidic chip and an emulsion preparation method, and belongs to the technical field of micro-fluidic chips. The chip comprises a focusing capillary tube, a collecting capillary tube, a square capillary tube, a sliding rail base module, a feeding module and a liquid inlet platform module. Focusing capillary tubes are inserted into the first and second side connectors of the liquid inlet platform, square capillary tubes are inserted into the second and third side connectors of the liquid inlet platform, and a collecting capillary tube is inserted into the right connector of the third liquid inlet platform; and the focusing capillary tube and the collecting capillary tube jointly extend into the square capillary tube. The whole forms a single-stage chip module, and a plurality of single-stage modules are connected in series through a rubber hose to form a multi-stage chip which is used for preparing complex micro-droplets and the like. The device adopts a split type modular structural design, and has the advantages that the assembly is convenient, the standardization can be realized, and the preparation efficiency of complex micro-droplets is improved. And the precise 3D printing technology is combined, mold opening is not needed, flexible machining of parts is achieved, and cost is reduced.

The invention discloses a phosphate inorganic intumescent flame-retardant coating for a transformer substation or a converter station as well as a preparation method and application of the phosphate inorganic intumescent flame-retardant coating. The coating is prepared from the following raw materials in parts by mass: 30 to 50 parts of phosphate, 10 to 20 parts of modified glass powder, 5 to 20 parts of an inorganic flame retardant, 3 to 20 parts of filler, 5 to 10 parts of a curing agent and 3 to 10 parts of an auxiliary agent, the modified glass powder is prepared by mixing one or two of glass powder with the melting point of 500 DEG C and glass powder with the melting point of 700 DEG C with glass powder with the melting point of 350 DEG C and then modifying with a silane coupling agent. When the phosphate inorganic intumescent flame-retardant coating prepared by the invention is burnt at 1200 DEG C, an intumescent flame-retardant carbon layer can be generated, a good fireproof effect on a matrix material can be achieved, the temperature-resistant time at 1200 DEG C reaches 60 minutes or more, normal-temperature curing can be realized, and the environment-friendly property of the phosphate intumescent flame-retardant coating is improved due to no chromium element in the formula of the coating.

The invention provides a manufacturing method of a printed circuit board with an ultra-thick copper layer and the printed circuit board with the ultra-thick copper layer, belongs to the technical field of printed circuit board manufacturing, and solves the problems that the printed circuit board with the ultra-thick copper layer is long in manufacturing period and large in line spacing. The method comprises the following steps: providing a substrate; the substrate is subjected to cutting and drilling treatment, and the substrate with positioning holes is obtained; carrying out electroplating etching treatment on the substrate with the positioning hole to obtain an electroplated and etched substrate; carrying out resin filling treatment on the electroplated and etched substrate to obtain a substrate filled with resin; performing copper deposition etching treatment on the substrate filled with the resin to obtain a printed circuit board after copper deposition etching; and performing resistance welding word processing on the printed circuit board after copper deposition etching to obtain the ultra-thick copper layer printed circuit board. According to the scheme, the production cycle of the ultra-thick copper layer printed circuit board is shortened, narrow-line-spacing circuit manufacturing of the ultra-thick copper layer printed circuit board is achieved, the product quality is controllable, and the production cost is reduced.

The embodiment of the invention discloses a video processing method and device, and relates to the technical field of Internet application. According to the main technical scheme, the method comprises the steps that in response to a first event, a third interface is displayed, and the third interface comprises information of multiple themes from a server side; in response to a selected event in the multiple themes, a first interface is displayed, and the first interface comprises multiple candidate videos corresponding to the selected theme; in response to a second event, the second event comprises selecting at least one candidate video from the plurality of candidate videos and displaying a second interface, the second interface comprises a target video obtained by performing aggregation processing on at least two videos, and the at least two videos comprise the at least one candidate video; and in response to an event for triggering release of the target video, sending information for releasing the target video to a server side. According to the invention, richer video publishing experience is provided for the user, and the video processing efficiency is improved.

The invention relates to a laser wire powder coaxial combined machining head for multiple beams, and belongs to the technical field of laser additive equipment, the laser wire powder coaxial combined machining head comprises a wire feeding assembly and a plurality of coaxial powder feeding nozzles, the plurality of coaxial powder feeding nozzles are arranged around the central axis of a wire in the wire feeding assembly, the coaxial powder feeding nozzles are connected with a lens group module, and the lens group module is connected with an optical fiber plug. The laser passes through the lens group module and is coaxial with the central axis of the coaxial powder feeding nozzles, an annular powder feeding channel is arranged in the coaxial powder feeding nozzles around the central axis of the coaxial powder feeding nozzles, the coaxial powder feeding nozzles are provided with powder feeding holes communicated with the annular powder feeding channel, and the central axis of a wire in the wire feeding assembly and the central axis of each coaxial powder feeding nozzle intersect at the same point. The device has the advantages that when the silk powder is fed at the same time, the silk powder can evenly absorb energy of laser, the problem of different directions is solved, the material utilization rate and the additive quality are improved, meanwhile, equipment adjustment is simplified, and the working efficiency is improved.

The invention discloses a high-deformability silicon-based ceramic core for a nickel-based single crystal blade and a preparation method of the high-deformability silicon-based ceramic core, and the high-deformability silicon-based ceramic core comprises the following substances in percentage by mass: 20-65 wt% of core-shell structure quartz glass powder, 30-75 wt% of fused quartz glass powder, 3-35 wt% of a mineralizer and 1-10 wt% of a special additive. The preparation method comprises the following steps: preparing core-shell structure quartz glass powder with various particle sizes, a mineralizing agent and a special additive; uniformly mixing the substances to obtain silicon-based ceramic powder, and uniformly mixing the silicon-based ceramic powder with a plasticizer to obtain silicon-based ceramic core slurry; filling and pressing to obtain a silicon-based ceramic core blank, and roasting to obtain the high-deformability silicon-based ceramic core. According to the method, the silicon-based ceramic core has the characteristics of excellent shrinkage yielding, strength yielding, creep yielding and the like in the solidification process of the high-temperature alloy liquid, and the problem that recrystallization is generated in an inner cavity of the nickel-based single-crystal high-temperature alloy blade is effectively solved.

The present application provides a capacitor structure and a method for forming the same, the method comprising: providing a semiconductor substrate; forming a groove in the semiconductor substrate, wherein the groove has a plurality of discrete columnar structures formed by a portion of the semiconductor substrate, wherein the plurality of columnar structures are distributed in an array; forming a first electrode layer on the top surface of the semiconductor substrate, the sidewall surface and the bottom surface of the groove, and the sidewall surface and the top surface of the columnar structure; forming a dielectric layer on the surface of the first electrode layer; forming a second electrode layer on the surface of the dielectric layer, wherein the second electrode layer fills the groove around the columnar structure. The method improves the electrostatic capacitance and breakdown voltage resistance of the capacitor structure, and realizes the manufacture of high-density silicon capacitors.

The invention relates to a manufacturing method of a novel high-temperature high-performance piezoelectric ceramic material, the manufacturing method is improved on the basis of a lead zirconate titanate piezoelectric ceramic material, the prepared ceramic material is suitable for a high-temperature environment through doping and process optimization, and the manufacturing method comprises the following steps: burdening and mixing, pre-sintering, secondary ball milling, granulating and forming, glue discharging and sintering. And machining, silver electrode firing and polarization testing are carried out. According to the manufacturing method of the piezoelectric ceramic material, components of the lead zirconate titanate piezoelectric ceramic are optimized, and neodymium oxide is doped into the lead zirconate titanate piezoelectric material, so that the performance of the ceramic is improved. By doping neodymium oxide, volatilization of the piezoelectric ceramic in lead can be effectively inhibited, deformation of the ceramic is reduced, and the piezoelectric ceramic is suitable for application and industrial production. Meanwhile, the Curie temperature of the ceramic is not obviously reduced, so that the preparation of the high-temperature piezoelectric ceramic is realized.

The invention belongs to the field of composite material manufacturing, and relates to a manufacturing method of a composite material box-shaped beam with closed-angle ends. The composite material cover plate of the composite material box-shaped beam can be manufactured, and the structural form of the composite material cover plate can well act on curing forming of the composite material box-shaped beam. According to the invention, the manufacturing of the composite material box-shaped beam, the inspection of the axial direction size, the inspection of the profile size and the like can be realized. The invention innovatively provides a metal joint structure to replace a commonly used metal hinge support arm, and the metal joint structure has a function of measuring the profile precision of the inner profile of the edge strip of the composite box-shaped beam. The invention innovatively provides a split combined type forming tool and a measuring tool, and realizes a manufacturing process method of the composite material box-shaped beam with the closed angle at the end part. The measuring tool is innovatively provided, the measuring tool can measure the axial direction size of the composite material box-shaped beam, and the measuring range is large.

The invention relates to a preparation method of CAR-T cells and a product thereof. A method for preparing a CAR-T cell according to the present invention comprises the step of introducing a cyclic mRNA into a T cell that does not contain a chimeric antigen receptor; and, the cyclic mRNA comprises a first cyclic mRNA encoding a chimeric antigen receptor; in addition, the first annular mRNA comprises the following sequence (a) or (b): (a) a translation starting sequence and a coding sequence; and (b) translating the starting sequence, the coding sequence and the insertion element sequence. In the method, the transfection efficiency of the annular mRNA is high, and the positive rate is as high as 90%; compared with preparation methods of viruses, transposon systems and the like, the process is simple, the production cost is greatly reduced, and the safety is also improved; compared with linear mRNA, the protein expression time is greatly prolonged.

The invention relates to injection molding equipment for producing traceless thin-wall injection molded parts, and belongs to the field of injection molding machines, the injection molding equipment comprises an injection system connected with a heating system for hot melting of plastics, and is characterized by comprising a mold closing box body, the injection system is connected with the mold closing box body, and the heating system is connected with the mold closing box body; a movable mold and two static molds are arranged in the mold closing box body, the injection system injects hot melting plastic into the static molds, and a flow dividing assembly used for guiding the hot melting plastic to only flow to one static mold each time is arranged in the mold closing box body. And a mold closing assembly which is used for driving the movable mold to be separated from one static mold and then immediately transferring the movable mold to the other static mold for mold closing is arranged in the box body. The injection mold has the beneficial effects that the movable mold is prevented from being idle in the material taking process of the mechanical arm, and therefore the production efficiency of injection products is improved.

The embodiment of the invention provides a preparation method of a photoelectric biosensor and the photoelectric biosensor, and relates to the technical field of photoelectric sensing, and the preparation method comprises the following steps: preparing a biomass derived hierarchical porous carbon PBAC material, preparing PBAC interface blending adsorption layer carbon slurry according to the biomass derived hierarchical porous carbon PBAC material, and preparing working electrode slurry; performing chemical etching on ITO conductive glass to prepare an electrode substrate, printing the working electrode slurry on the electrode substrate by using a screen printing technology, and printing PBAC interface blending adsorption layer carbon slurry on the electrode substrate to obtain a working electrode; a colloidal gold solution is dropwise added to the working electrode, after drying, a probe solution is dropwise added to the surface of the working electrode again, incubation is conducted in a constant-temperature box, and the photoelectrochemical biosensor is obtained after the reaction is completed. According to the invention, the biocompatibility of the photoelectric biosensor is enhanced, and the stability and sensitivity of the sensor are improved.

The invention provides a regeneration method of an aluminum-silicon alloy, a regenerated silicon-aluminum alloy and an iron-rich phase alloy. The regeneration method comprises the steps that S1, raw materials of the aluminum-silicon alloy are smelted, and a first melt is obtained; s2, an aluminum-manganese intermediate alloy and an aluminum-chromium intermediate alloy are added into the first melt, and a second melt is obtained; the second melt contains Fe element, Mn element and Cr element; s3, refining treatment is conducted on the second melt, and a third melt is obtained; and S4, the third melt is added into a casting mold, mechanical vibration is conducted on the casting mold under the vibration condition so that the third melt can be solidified, and the regenerated aluminum-silicon alloy and the iron-rich phase alloy are obtained. Vibration equipment is used for applying a vibration field to the casting mold, and meanwhile, the proportion of alloy elements and the smelting process are accurately controlled in a matched mode, so that preparation of the low-iron secondary aluminum-silicon alloy is achieved.

The invention discloses a method for designing and preparing an ultrathin conducting layer of a micro-hemispherical resonator gyroscope. The method comprises the following steps: obtaining thin film thickness distribution data of the inner surface of a micro-hemispherical resonator; calculating the deformation energy of each region of the micro-hemispherical harmonic oscillator, and enabling the region of which the proportion of the deformation energy to the whole body is smaller than a first threshold value on the micro-hemispherical harmonic oscillator to be a region A, and enabling the others to be a region B; based on the relation curve of the resistivity and the film thickness, the film thickness r corresponding to the inflection point of the resistivity is obtained; the film thickness rA of the area A and the film thickness rB of the area B are equal to a * r and b * r, and a and b are the maximum values of the film thickness ratio of the plane area to the area A and the area B; and carrying out performance detection after coating the inner surface of the micro-hemispherical harmonic oscillator based on the rA and the rB, and iterating the rB until the rB passes the performance detection. The method is applied to the technical field of micro electro mechanical systems, and can reduce the thickness of the film in an area with a larger deformation energy ratio of the micro-hemispherical harmonic oscillator on the premise of ensuring the conductivity of the metal film, thereby achieving the purpose of improving the performance.

The invention discloses a preparation method of a chitosan oligosaccharide-anthocyanin nanocomposite. The preparation method comprises the following steps: dissolving purple corn anthocyanin in distilled water; dissolving chitosan oligosaccharide in distilled water; the method comprises the following steps: adding an organic solvent into a reaction kettle, reacting at room temperature in a dark place for 4-48 hours, transferring a mixed solution into a centrifugal tube, centrifuging for 10-30 minutes to separate out nano-composite precipitates and uncombined supernatant, and then adding ultrapure water for repeated centrifugation. And finally, carrying out freeze drying treatment on the precipitate to obtain the final chitosan oligosaccharide-anthocyanin nano-composite. The nano-composite prepared by the method has high stability, good dispersibility and enhanced biological activity, and provides a new way for wide application of chitosan oligosaccharide and anthocyanin in the fields of food, cosmetics, biological medicine and the like.

The invention discloses a cold heading method which comprises the following steps: performing primary punching on a second intermediate obtained by shearing and positioning and slotting the upper and lower bottom surfaces to obtain a third intermediate, performing secondary punching on the third intermediate through a cold heading machine to obtain a fourth intermediate, and performing secondary punching on the fourth intermediate to obtain a fifth intermediate. And the fourth intermediate is subjected to equal-diameter stretching through the cold header to obtain a fifth intermediate, the fifth intermediate is subjected to shape correction through the cold header, and the slender pipe fitting is formed. According to the method, the blank is subjected to primary punching and secondary punching, the shaft-shaped intermediate with the two outer diameter sizes and the counter bores in the bottom is obtained, the intermediate subjected to secondary punching is subjected to equal-diameter stretching through the counter bores and then is corrected, an existing upsetting process is changed, and preparation of the long and thin pipe fitting is achieved.

A single laser modulation small magneto-optical trap comprises a laser device, and main laser emitted by the laser device forms a first cooling light beam, a second cooling light beam, a third cooling light beam and a feedback light beam through beam splitting and reflection; the cooling light beams form six magneto-optical trap light paths, wherein every two of the six light beams are oppositely emitted and intersect at one point in the vacuum cavity, and a magneto-optical trap is formed under the action of a gradient static magnetic field formed by the first magnetic field coil and the second magnetic field coil. The feedback light beam penetrates through the rubidium steam chamber and is converted into re-pumping light through the photoelectric probe, the modem, the frequency locking controller and the electro-optical modulator in sequence, and the laser combines the re-pumping light and generated main laser. The device is low in complexity of a laser light path, low in cost and high in precision; the vacuum glass cavity is low in scattering, high in transparency, low in thermal expansion coefficient and good in vacuum sealing performance, good optical performance and stability can be provided, and meanwhile the influence of magnetic field interference and thermal expansion is reduced.

The invention discloses carbon nanoelectrode production equipment, a preparation method and an annealing process, the production equipment comprises a heating cabin, a carbon heater is fixed in the center of a shell of the heating cabin, a protective gas inlet is formed in a back plate of the shell, a water-cooling heat exchanger is arranged on the peripheral side of the shell, and the protective gas inlet is externally connected with a protective gas source and is correspondingly provided with a protective gas valve; the lifting unit comprises a linear sliding table and a connecting rod arranged at the action end of the linear sliding table, the connecting rod is provided with a probe fixing clamp, the probe fixing clamp clamps a probe, the probe moves towards or away from the heating cabin in the length direction of the probe, the shell is provided with an insertion hole corresponding to the probe, and the tail end of the probe is connected with a carbon source or a vacuum pump. A carbon source control valve is arranged on the hose corresponding to the carbon source; and the control unit comprises a control circuit board and a switching power supply for providing electric energy, and controls the action part to act according to preset parameters. The production equipment has the advantages of being high in automation and program control degree, good in reproducibility, high in safety and easy and convenient to operate.

The invention provides high-sphericity micro-nano silver powder and a preparation method thereof, and belongs to the technical field of metal powder preparation. The preparation method comprises the following steps: preparing a base solution by adopting polyvinylpyrrolidone, silver nitrate, a first reducing agent and a second reducing agent, respectively preparing a silver nitrate solution, a third reducing agent solution and a sodium hydroxide solution, quickly dripping the silver nitrate solution and the third reducing agent solution into the base solution at the same time, and after the reaction is complete, obtaining the silver-silver composite material. And adding a sodium hydroxide solution to adjust the pH value to 6.5-8, fully stirring, standing, separating out settled silver powder, washing, and drying to obtain the high-sphericity micro-nano silver powder. According to the preparation method, the technical scheme is reasonably designed, the characteristics of polyvinylpyrrolidone, sodium borohydride, ascorbic acid and sodium hydroxide are fully utilized, reagents are matched with one another, and preparation and particle size regulation and control of the spherical silver powder are achieved. The adopted raw materials are non-toxic and pollution-free, the technological process is short, the base solution can be used after being prepared, the batch stability is high, and kilogram-level amplified production is achieved.

The invention provides a silicon epitaxial wafer capable of reducing edge microcrack defects and a preparation method thereof. The preparation method comprises the following steps: etching a reaction cavity and a graphite base; coating the graphite base with silicon; a silicon substrate slice is placed in the slice pit; hydrogen and trichlorosilane are introduced into the reaction cavity, growth of a silicon epitaxial layer is carried out, the initial flow of trichlorosilane is 4-6 g / min, the initial growth rate is 0.9-1.1 [mu] m / min, and after growth is carried out for 1-2 min, the flow of trichlorosilane is adjusted to be 10-12 g / min, the growth rate of the silicon epitaxial layer is adjusted to be 1.8-2.0 [mu] m / min, and the target thickness is achieved. According to the preparation method, parameters such as silicon coating time, wafer placing temperature, growth temperature, growth rate and the like are regulated and controlled, the probability that microcrack defects appear on the edge of the thick-layer silicon epitaxial wafer is reduced, the process is simple, batch repetition can be achieved, and preparation and batch production of the silicon epitaxial wafer with the diameter being 125-200 mm and the target silicon epitaxial layer thickness being 50-120 microns are achieved.