178results about How to "Good size control" patented technology

The invention belongs to the field of biomedical materials, and provides a chiral multilevel structure antibacterial film and a preparation method and application thereof, and in the preparation process of the film, atomic-level nanosheets are assembled to form a microenvironment with a chiral multilevel structure. The adhesion behavior of bacteria can be selectively regulated and controlled through a chiral multilevel structure, and the growth of a bacterial biofilm is controlled, so that an antibacterial effect is generated. Besides, the nanosheet plays a role of a blade array and also provides a physical tool for destroying a bacterial membrane, the D-CHAPFs with the blade array structure has the effect of inhibiting the growth of the bacterial biomembrane, and the inhibition rate is 90-96%. The antibacterial film is beneficial to repair of infected wounds while resisting bacteria. Based on the above points, construction of a chiral multilevel structure microenvironment, selective regulation and control of bacterial adhesion behaviors and regulation and damage of bacterial membrane growth are realized, and an antibacterial function is realized on the whole.

The invention relates to the technical field of catalysts for gas purification, in particular to a hierarchical pore metal-based catalytic adsorbent as well as a preparation method and application thereof. The invention discloses an integrated preparation method combining a sol-gel method and a template method, which comprises the following steps of: adding a template agent before forming gel, adding a proper amount of ammonia water in an aging process, accurately controlling other reaction conditions and a raw material ratio, and controlling a spatial confinement effect of the template method and a chemical reaction in a sol-gel process to obtain a sol-gel composite material. The morphology and size of the catalytic adsorbent can be accurately regulated and controlled, the hierarchical pore metal-based catalytic adsorbent with a microporous structure as a main material and mesopores and macropores as coexistence is finally prepared, the hierarchical pore structure provides rich adsorption sites and catalytic activity centers, and the hierarchical pore metal-based catalytic adsorbent has high adsorption capacity, high selectivity, good catalytic activity, good stability and easy regeneration.

The invention relates to a montmorillonite-probiotic microsphere preparation as well as a preparation method and application thereof, the microsphere preparation comprises montmorillonite, a probiotic biofilm and functional small molecules, and microspheres of the microsphere preparation are prepared by crosslinking sodium alginate in a collection solution based on a microfluidic technology. The microsphere preparation is mainly used for oral delivery of montmorillonite-probiotic biofilms and functional small molecules, so as to treat intestinal diseases. Compared with the prior art, the microsphere preparation provided by the invention has the advantages of gastric acid invasion resistance, intestinal responsive release and the like, and can effectively treat intestinal inflammation. In addition, the probiotic biofilm wrapped by the microspheres can enhance the interaction with the intestinal mucosa and prolong the residence time in the intestinal tract. Meanwhile, the used functional small molecules have excellent anti-inflammatory and intestinal barrier repairing effects, and can cooperate with the probiotics to regulate and control intestinal flora, so that the intestinal health is further improved.

The invention belongs to the technical field of biomedical nano material preparation, and provides defect-rich cobalt-zinc-tungsten hydrotalcite as well as a preparation method and application thereof. According to the preparation method disclosed by the invention, based on the controllability and defect engineering of two-dimensional layered double hydroxides (LDHs) main body laminate metal elements and interlayer anions, W < 6 + > / W < 5 + > and Co < 3 + > / Co < 2 + > conversion systems are introduced by regulating and controlling the influence rule of laminate metal composition, arrangement, density, orientation and etching conditions on the photodynamic activity of the LDHs; and when the defect-rich cobalt-zinc-tungsten hydrotalcite is used as the photosensitizer, the ROS yield is high. Through biological effect and metabolic behavior research, the defect-rich cobalt-zinc-tungsten hydrotalcite with good biocompatibility and excellent performance is selected, and a theoretical basis is provided for application of the defect-rich cobalt-zinc-tungsten hydrotalcite to treatment of HCM.

The invention discloses a preparation method of a high-entropy phosphide nanotube, which successfully prepares a nanotube phosphide with a high-entropy structure by adopting a hydrogen bond organic framework (HOF)-metal organic framework (MOF) template conversion method. In the preparation process of the material, a core-shell structure (HOF (MOF)) is firstly formed, the core gradually disappears through a diffusion mechanism, and finally, the material is converted into a hollow nanotube structure which is uniform and controllable in size. According to the hollow structure, the specific surface area is remarkably increased, more active sites are provided, the transmission path of reactant molecules is optimized, and the electro-catalytic performance is greatly improved. Besides, the overall tubular morphology of the material is uniform, the size is controllable, and compared with a traditional granular material, the specific surface area is remarkably increased, so that more reaction sites are exposed in the external environment, and the catalytic efficiency and the reaction rate of the material in an electro-catalytic reaction are greatly improved.

The invention discloses a quick-plug type high-voltage bus bar connecting structure which comprises a roll-shaped reed, a plurality of axial connecting strips and axial cantilever strips, the axial connecting strips and the axial cantilever strips are alternately arranged at intervals in the circumferential direction, and the two ends of the axial connecting strips in the length direction are integrally connected with the two axial ends of the roll-shaped reed. Only one end of the axial cantilever strip in the length direction is integrally connected with one axial end of the rolled reed; the socket sleeve is assembled with the outer ring of the rolled reed, the inner wall of the socket sleeve is provided with two inner protruding edges protruding inwards in the radial direction, the two shaft ends of the rolled reed abut against the inner protruding edges respectively, and the inner protruding edges can limit the longest axial size of the rolled reed; the corresponding inner diameter sizes of the roll-shaped reeds in the middle of the axial connecting strip and the axial cantilever strip are smaller than the corresponding inner diameter sizes of the roll-shaped reeds in the two ends of the axial connecting strip and the two ends of the axial cantilever strip; the roll-shaped reed is made of an integrated conductive elastic material. The high-voltage electric connector can be used for high-voltage electric connection, the rolled reeds bring good elastic clamping force, and the machining cost is low.

The invention provides a power module, which comprises a first side plate, a second side plate and an insulating plate, and is characterized in that the insulating plate comprises a flat plate part, one or more lug bosses and one or more communication bridges; the protruding part and / or the communication bridge protrude / protrudes in the third direction so as to form an insulation cavity. The insulating plate, the first side plate and the second side plate are combined to form a first accommodating space and a second accommodating space along a third direction, a first power device is arranged in the first accommodating space, and a second power device is arranged in the second accommodating space; the transformer comprises a magnetic core and a winding wound on the magnetic core, the winding comprises a first winding and a second winding, and at least part of the magnetic core is arranged in the insulation cavity or the communication bridge; the first winding is electrically connected with the first power device, and the second winding is electrically connected with the second power device. The flat plate part does not penetrate through the magnetic core air gap, so that the size of the magnetic core air gap is convenient to control, and the efficiency of a transformer in the power module is improved.

The invention discloses a three-dimensional woven composite material plate spring type undercarriage prefabricated body profiling forming tool and method. The three-dimensional woven composite material plate spring type undercarriage prefabricated body profiling forming tool comprises a tool frame, a core mold, five clamps and five connecting rollers. The three-dimensional woven composite material plate spring type undercarriage structure prefabricated body comprises nine areas including a first uniform cross-section area, a first variable cross-section area, a second uniform cross-section area, a second variable cross-section area, a third uniform cross-section area, a third variable cross-section area, a fourth uniform cross-section area, a fourth variable cross-section area and a fifth uniform cross-section area, vertical parts are arranged on the two sides of a plate spring, an arc part is arranged in the middle of the plate spring, and the plate spring is of a symmetrical structure. The thicknesses of the fabrics in different areas are different, variable-thickness integrated weaving is adopted in the weaving process, and the fabric areas comprise binding warp yarns and weft yarns. The defects that an existing undercarriage prefabricated body is woven in blocks and cannot be integrally formed can be overcome, better size control and good mechanical performance are achieved, the three-dimensional woven composite material is adopted, and the undercarriage prefabricated body has the advantages of being large in specific stiffness and high in specific strength and further has excellent layering resistance and impact resistance.

The invention discloses a waste lithium battery electrode recycling and regenerating method which comprises the following steps: (1) crushing a waste lithium battery electrode and carrying out acid leaching with sulfuric acid, hydrochloric acid or phosphoric acid to obtain an acid leaching solution; (2) adding 1.2-2.0 equivalent weight of iron powder into the pickle liquor according to the molar weight of copper ions in the pickle liquor under the protection of inert gas, reacting for not less than 30 minutes, adjusting the pH value to 1.5-2.0 by using ammonia water, and filtering to obtain a first impurity-removed solution; (3) adding not less than 0.05% of an antioxidant into the first impurity-removed solution by mass, adjusting the pH value to 2.6-3.5 by using ammonia water, and filtering to obtain a second impurity-removed solution; and (4) adding a manganese-containing composition into the second impurity-removed solution, and heating to 90-100 DEG C, so that ferrous ions are separated out in the form of lithium manganese iron phosphate double salt, and the precipitate is the regenerated electrode material. Impurities in the electrode are removed and recycled in a non-oxidation mode, the technological process is shortened, high-temperature and high-pressure conditions are not needed, and the preparation process is milder.

According to the preparation method of the high-temperature-ablation-resistant heat-insulation aerogel, a plasticizer polyethylene glycol is introduced into a graphene and silicon dioxide dispersion liquid for composite film laying, then a solvent plasticizing foaming technology is utilized for preparing the composite aerogel, and the prepared aerogel has the ablation-resistant function and the excellent heat insulation function; and meanwhile, the material has the advantages of light weight, good compression resilience and the like, and can be repeatedly used by maintaining the original shape and performance at high temperature. The scheme has the advantages of simple process, controllable process, low reaction conditions, suitability for industrial production and the like.

The invention provides composite silver soldering paste and a preparation method and application thereof.The preparation method comprises the following steps that silver nitrate and PVP are dissolved in an ethylene glycol solution, and stirring is conducted for 20-45 min through a constant-temperature magnetic stirrer at the temperature of 45-75 DEG C; adding a certain amount of HCl into the mixed solution, magnetically stirring for 15-30 minutes, and cooling to room temperature; putting the mixture into a reaction kettle, and performing vacuum constant-temperature heating for 150-200min at 100-190 DEG C; and after washing with deionized water and absolute ethyl alcohol, carrying out ultrasonic treatment to obtain the composite silver soldering paste. According to the multi-scale composite silver soldering paste, an ethylene glycol reduction method is adopted, silver ions in a solution are reduced into silver atoms, submicron or micron particles are secondarily grown on the basis of nano-silver particles, and the multi-scale composite silver soldering paste is prepared and has better electrical and mechanical properties; the multi-scale silver particles are easy to generate, the reaction conditions are easy to control, the preparation method is simple, safe and environmentally friendly, the needed raw material types are few, the number of devices is small, few organic matter is added, and the nano-silver particles controllable in morphology and size are easy to obtain.

The application belongs to the technical field of optical materials, and particularly discloses a synthesis method of core-shell quantum dots based on surface activation, which comprises the following steps: S1, preparing a quantum dot core; S2, degassing reaction is carried out on zinc precursor, octadecene and oleylamine in proportion, then the quantum dot core obtained in S1 is injected, a metal alkyl compound is added, and the temperature is increased to 230-250 DEG C; S3, the shell precursor is injected for 3-4 times, the temperature is increased at the same time, the inner shell is grown, zinc stearate and TOP-S are injected again, the ZnS shell is grown, and the InP core-shell quantum dots with regular morphology are obtained. The synthesis method of core-shell quantum dots based on surface activation is adopted, the quantum dots with controllable morphology and size distribution are obtained, the method is suitable for industrial production, and has wide applicability.

This invention discloses a Pickering emulsion based on silk fibroin self-assembled particles and its preparation method. The preparation method includes the following steps: adjusting the pH of the silk fibroin solution to 4.0-4.5, adding NaCl to a final concentration of 0.05-0.1 mol / L, mixing, and then heating to 40-50 °C and allowing it to stand at a constant temperature. Using the obtained silk fibroin self-assembled particle dispersion as the aqueous phase and vegetable oil as the oil phase, the mixture is mixed with excipients and homogenized by high-speed shearing to obtain a primary emulsion. This primary emulsion is then treated by high-pressure microfluidic jet to obtain the Pickering emulsion based on silk fibroin self-assembled particles. This method requires no chemical modification or exogenous reagents, is green and simple, and does not use organic solvents. It can prepare emulsions with high biosafety and high storage stability without emulsifiers, improving process safety and scalability, and broadening its application in the food, cosmetics, and biopharmaceutical fields.

This invention provides a wireless, passive force-position implantable growth monitoring system and its fabrication method for early-onset scoliosis correction. The system includes: a connected compressible capacitive sensor and a flexible wireless antenna coil; the compressible capacitive sensor is connected to a self-growing early-onset scoliosis correction implant growth rod, and the flexible wireless antenna coil is disposed within the body. The compressible capacitive sensor and the flexible wireless antenna coil together constitute an LCR resonant circuit; the compressible capacitive sensor monitors the pressure changes caused by the elongation of the self-growing early-onset scoliosis correction implant growth rod during tissue or bone growth, thereby causing changes in capacitance and resulting in changes in the resonant frequency of the LCR resonant circuit; the resonant frequency change is detected and read out wirelessly via an external readout device. This system is designed to meet the needs of digital rehabilitation, requires no internal power supply, and has a stable structure, making it suitable for growth monitoring after early-onset scoliosis correction surgery.

The application provides a preparation method and a centering device of a size-controllable ultrathin high-quality echo wall optical crystal microcavity, and the method comprises the following steps: cutting a crystal material into a wafer and grinding and thinning the crystal thickness by using a polishing disc; placing an optical crystal microcavity blank on a microscope stage, adjusting two-dimensional adjustment knobs of the stage, and making the center of the optical crystal microcavity blank coincide with an origin of an objective micrometer scale; making a clamping rod with an adhesive adhered to a bottom end penetrate a top end through hole of a clamping rod fixing frame, and making the clamping rod align with the origin of the objective micrometer scale; adjusting the height of the clamping rod, making the optical crystal microcavity blank be pasted and fixed on the bottom end of the clamping rod by ultraviolet curing glue, and completing centering; taking the clamping rod off the clamping rod fixing frame, chamfering an outer circle of the optical crystal microcavity blank; grinding the outer circle surface of the optical crystal microcavity wafer by using sandpaper; polishing the optical crystal microcavity wafer, and obtaining the optical crystal microcavity based on the polished optical crystal microcavity wafer.

The invention relates to a VOx nanoring for a lithium ion battery negative electrode material, a preparation method of the VOx nanoring, the lithium battery negative electrode material and a lithium battery. The preparation method comprises the following steps: S100, preparing raw materials: preparing sodium orthovanadate and thioacetamide; s200, mixing the raw materials to obtain a mixed solution; s300, carrying out heating reaction to generate turbid liquid with a stable nanometer annular structure; and S400, cooling and separating, namely taking out the turbid liquid in the high-pressure kettle, cooling to room temperature, separating by a centrifugal machine, cleaning and drying to obtain the dry nanoring capable of being used for the lithium battery negative electrode material. The preparation method disclosed by the invention is convenient, simple, good in repeatability, high in yield and capable of realizing large-scale production and industrialization. The prepared nanoring structure can be kept stable for a long time, the size and morphology of the nanoring are controllable, and the morphology can be regulated and controlled through the reaction time, the reaction temperature, the reactant ratio and the like.

The invention belongs to the technical field of thermal performance testing, and particularly relates to an assemblable phase change wall thermal performance testing device which comprises an outdoor environment box, an indoor environment box is fixedly connected to the interior of the outdoor environment box, temperature measuring devices and temperature adjusting devices are installed in the outdoor environment box and the indoor environment box, one end of the indoor environment box is open, and the other end of the indoor environment box is open. The open end of the indoor environment box is fixedly connected with a phase change wall test piece frame through a connecting structure, a phase change wall body is installed in the phase change wall test piece frame, the connecting structure comprises a plurality of lock seats and a plurality of clamp lock catch lock hooks, the lock seats are fixedly connected to the peripheral side of the phase change wall test piece frame, and the clamp lock catch lock hooks are fixedly connected to the clamp lock catch lock hooks. And the plurality of clamp lock catch locking hooks are fixedly connected to the peripheral side of the indoor environment box respectively. According to the invention, the indoor and outdoor environment of the phase change wall can be accurately simulated, the limitation of the test temperature, the test wall size and the test environment is small, the comprehensive and accurate evaluation of the thermal performance of the phase change wall is realized, and the scientific research test requirements are well met.

The invention discloses a method for preparing a hydroxyapatite-modified carbon nitride (HA / g-C3N4) composite material having both heavy metal ion adsorption and visible light catalytic performance, and the steps are as follows: dissolving melamine and thiourea in deionized water, stirring evenly, then adding HA for ultrasonic dispersion, transferring the resulting solution to a reactor for reaction at 180°C for 12 hours, cooling to room temperature and filtering, drying the filter cake to obtain a HA / g-C3N4 composite material precursor; grinding the precursor evenly in an agate mortar, placing the ground powder in a crucible, and calcining to obtain a HA / g-C3N4 composite material. The HA / g-C3N4 composite material prepared by the method has the advantages of simple and rapid preparation process, easy operation, environmental protection, large product yield, simple post-processing, and controllable product morphology, size and composition, etc., especially in the field of heavy metal ion adsorption and visible light degradation of pollutants, and has good application prospects.

The present invention discloses a stop device of an electronic expansion valve and a method for installing a stopper. The stop device of the electronic expansion valve includes a core shaft, a stop ring and a stopper. The stop ring is sleeved on the core shaft and can be spirally rotated along the axial direction of the core shaft; a plurality of grooves are provided on the side wall of one end of the core shaft along the radial direction of the core shaft; the stopper includes an annular block, a plurality of protrusions and a stopper; the annular block is sleeved on one end of the core shaft with the groove; one end of the plurality of protrusions is fixed on the inner side wall of the annular block close to the core shaft, and the other end of the protrusion is inserted into the corresponding groove; the stopper is fixed on the outer wall of the annular block away from the core shaft and has a plane one; the plane one is used to stop the rotation of the stopper ring. In the present invention, since the stopper is used to stop the stopper ring, the top end of the elastic member is not subjected to the stopping force and the stopping force is only borne by the stopper alone. The elastic member will not be deformed, so as not to affect the sliding of the stopper ring.

A manufacturing method of a circuit board comprises the following steps that a first substrate is provided and comprises a first dielectric layer and a first copper layer, and the first copper layer is located on the surface of the first dielectric layer; cutting a part of the first dielectric layer along the direction in which the first dielectric layer and the first copper layer are stacked, so as to reduce the thickness of the first dielectric layer in a part of area, thereby forming a thinned layer; two blind holes are formed in the thinning layer, and the first copper layer is exposed out of the blind holes; forming a resistance layer in the blind holes and on the surface of the first dielectric layer between the two blind holes, wherein the resistance layer is connected with the first copper layer; and providing a bonding layer and a second substrate, arranging the bonding layer between the second substrate and the surface of the first substrate with the resistive layer, and pressing to form the circuit board. The invention further provides a circuit board.

The embodiment of the invention provides a preparation method of a high-dispersion lamellar ZSM-5 molecular sieve, and relates to the field of molecular sieve preparation. S1, preparing a seed crystal solution; s2, mixing a tetrapropylammonium hydroxide solution, deionized water, a silicon source and the seed crystal solution prepared in the step S1 to obtain a solution B; s3, adding an aluminum source into the deionized water, and dissolving the aluminum source into the deionized water; s4, deionized water in which an aluminum source is dissolved is added into the clarified solution in the step S2 to be stirred, and a white solution C is obtained; s5, adding the additive into the deionized water, and enabling the additive to be dissolved in the deionized water; s6, adding deionized water in which an additive is dissolved into the solution C in the step S4, stirring, and then putting the solution into a crystallization kettle for crystallization to obtain a crystallized sample; and S7, carrying out drying treatment on the crystallized sample, and roasting to obtain the lamellar ZSM-5 molecular sieve.

The invention provides a preparation method of a PEM water electrolysis membrane electrode, which relates to the field of PEM water electrolysis hydrogen production. Titanium dioxide nanotubes are used as supporting materials to prepare an anode diffusion layer. Because the tube structure has high gas and liquid conductivity, it is beneficial to the separation of oxygen and water in the water electrolysis process. The titanium dioxide nanotubes are calcined at high temperature to transform into a rutile lattice structure, which has high conductivity and stability. The anode diffusion layer is prepared by stacking multiple thin single-layer supporting layers, and the porosity can be controlled within a suitable range. The anode diffusion layer has higher mechanical strength, plays a supporting role, meets the mechanical strength requirements of the water electrolyzer during operation, has higher porosity, and can effectively improve the transmission of water and gas between layers. The precious metal undergoes a solid phase reaction to be embedded in the surface of the rutile titanium dioxide nanotubes to form a dense catalytic conductive network structure, which is not easy to fall off, and can realize the batch preparation of membrane electrodes.

The invention provides a quantum dot, a preparation method thereof, a composition and a photoelectric device. The quantum dot comprises an inner core and a ZnSe shell layer located on the surface of the inner core; the ZnSe shell layer comprises at least four ZnSe single-layer structures, a ZnS shell layer can be further controllably grown on the surface of the ZnSe single-layer structures, surface ligands of the quantum dots comprise long straight-chain zinc carboxylate ligands, zinc carboxylate ligands containing branched chains and short straight-chain zinc carboxylate ligands, and the quantum dots are spherical quantum dots. The quantum dot provided by the invention is controllable in structure, shape and size and uniform in morphology, crystal face-ligand stress of the ZnSe shell layer is fully released, tensile stress generated by mismatching of core-shell crystal lattices of the quantum dot is obviously relieved, a core generates relatively weak compressive stress, and under the synergistic effect of surface ligands of the quantum dot, the quantum dot has a relatively strong compressive stress on the surface of the ZnSe shell layer. The quantum dot has the fluorescence (PL) quantum yield close to 100%, and the photophysical stability and photochemical stability are improved.

The invention provides a transmission electron microscope sample preparation device and method for high-entropy alloy nanoparticles, and relates to the field of high-entropy alloys and microscopic characterization thereof. The preparation device comprises a substrate and a round cover with holes, grooves of the substrate are in one-to-one correspondence with the holes in the round cover, and the device is made of a metal material with high temperature resistance. According to the preparation method provided by the invention, transmission electron microscope characterization results of the nanoscale high-entropy alloy particles and the high-quality high-entropy alloy nanoparticles can be obtained. The obtained high-entropy alloy particles are uniform in distribution, controllable in size and high in experiment success rate, and a plurality of samples can be prepared at the same time. Through the pulse laser deposition technology, the high-entropy alloy nano-particles which are evenly distributed and controllable in size can be obtained, the experiment success rate can be increased, pollution in the experiment process can be avoided, the capacity of preparing a plurality of transmission electron microscope samples at the same time is achieved, and a high-quality microscopic characterization result can be obtained; and the quality and the preparation efficiency of the high-entropy alloy transmission electron microscope nanoparticle sample are remarkably improved.

The invention relates to the field of pipelines, in particular to a PE profile which at least comprises a first PE layer and a second PE layer, the first PE layer is of a strip-shaped structure, and the second PE layer wraps and is welded to the peripheral side wall of the first PE layer. According to the PE profile, the second PE layer wraps the first PE layer and is welded to the first PE layer, so that the size of the PE profile can be increased, namely, the size of the PE profile is increased by wrapping the core material layer by layer instead of directly extruding and molding the PE profile to a specified size at a time, and the outer wrapping layer can be welded to the core material by utilizing the material characteristics of PE; therefore, the core material can be independently cooled and then is coated with the outer cladding layer to form the PE profile, the problems that a large-size PE profile is directly extruded and processed, internal cooling is slow, and stable forming is difficult are solved, and the PE profile is convenient to manufacture, stable in structure, convenient to control in size, high in yield and good in effect.

This invention discloses a method for preparing van der Waals metal thin films. The method includes the following steps: S1, coating a polyvinyl alcohol (PVA) film onto the surface of a supporting substrate; S2, depositing a metal film on the surface of the PVA film to obtain an intermediate; S3, placing the intermediate in water at 60-80°C to remove the PVA film, obtaining a floating metal film; transferring the metal film to the surface of a target substrate, and bonding the two together using van der Waals forces to obtain the final product. This invention utilizes the controllable dissolution properties of PVA, achieving the separation and transfer of the metal film from the supporting substrate using deionized water, avoiding the use of toxic chemical solvents and interface damage caused by high-energy bombardment. The method is simple, environmentally friendly, and can be widely applied to the preparation of van der Waals heterostructures such as metal-semiconductor and metal-insulator structures.

This invention discloses a core structure for a highly reliable electronic gear shifter, including a bracket, side plates, a toothed plate, and a shifting assembly. The shifting assembly includes a left shift block, a shift lever, a right shift block, steel balls, a locking plate, a locking spring, a gear position spring, and a sleeve. The shift lever is clamped and fixed by the left and right shift blocks. The cylindrical boss of the left shift block is tightly fitted with the inner hole of the large bearing, and the pin hole of the right shift block is tightly fitted with a pin, which is also tightly fitted with the inner hole of the small bearing. The locking spring and locking plate slide within the inner cavities of the left and right shift blocks, the steel balls and gear position spring move within the inner hole of the sleeve, and the steel balls and locking plates are slidably connected to the toothed plate. The unlocking lever slides within the shift lever. This invention enhances the shifting operation feel, increases the service life of the gear shifter, improves the strength and structural reliability of the gear shifter, and the locking function avoids the risk of misoperation.

The invention provides a preparation method of a porous electrode, the porous electrode and application of the porous electrode. The preparation method comprises the following steps: performing first etching on at least one surface of an electrode current collector to obtain an electrode current collector with holes; filling holes in the electrode current collector with a pore-filling agent, and performing second etching on a region, which does not contain the pore-filling agent, in the filled electrode current collector, so that the electrode current collector has surface pore-filling agent bulges, thereby obtaining a to-be-used electrode current collector; coating the surface of the to-be-used electrode current collector with electrode slurry to obtain a to-be-treated electrode; and removing the pore filling agent from the electrode to be treated to obtain the porous electrode. According to the preparation method provided by the invention, the preparation of the electrode with the low-tortuosity pore structure is really realized, so that the continuous batch preparation of the battery with the low-tortuosity electrode is realized, the operability and the high efficiency are realized, and the problem that the capacity, the rate and the cycle performance of the current thick electrode are relatively poor due to ion transmission limitation is solved.

The invention discloses a method for industrially producing nano-metal particles on a large scale, which comprises the following steps of: growing nano-metal particles on a graphene composite carbon fiber electrode in situ by adopting a direct current electroplating mode, and enabling the nano-metal particles deposited at a vertical graphene edge to fall off and sink by utilizing an ultrasonic vibration mode. The size of the metal nano-particles is controlled, the metal nano-particles fall off the surface of the electrode in time, and therefore continuous and large-batch production is achieved. The method for obtaining the nano-metal particles is carried out in a normal-temperature aqueous solution, the process is simple, energy is saved, consumption is low, and large-scale preparation of the metal nano-particles can be achieved; and no toxic or harmful gas is generated in the production process, so that the method is environment-friendly.

The invention relates to the technical field of catalysts, in particular to a catalyst for preparing ethyl alcohol through methyl acetate hydrogenation and application of the catalyst. In the catalyst, a carrier is Al2O3; the active component is CuOx (x is less than or equal to 1); the auxiliary agent is ZnO; the preparation method of the catalyst comprises the following steps: respectively dissolving pseudo-boehmite in a sodium bicarbonate solution to prepare a suspension, preparing a salt solution from soluble copper salt and soluble zinc salt, and preparing an alkali solution with the same concentration as the salt solution; dropwise adding a salt solution and an alkali solution into the suspension, sequentially aging and filtering, and repeatedly pulping and filtering a filter cake to obtain a coprecipitation product; and drying, grinding and granulating the coprecipitation product, roasting and decomposing, uniformly mixing the obtained decomposed product with a forming agent, and tabletting and forming to obtain the catalyst. The catalyst provided by the invention is simple in preparation method, easy to operate, environment-friendly, low in cost and excellent in catalytic activity, and has a good industrial application prospect.