28results about How to "Avoid Structural Defects" patented technology

The invention discloses a method for manufacturing a tube body with a three-layer structure, a medical cannula and a catheter pump, the method comprises a preset procedure at least used for forming an outer side structure layer on a core rod, and the preset procedure comprises the steps of obtaining fan-shaped sheets, folding the fan-shaped sheets in the circumferential direction of a variable-diameter section, and limiting and fixing the fan-shaped sheets on the outer side of the variable-diameter section, a conical pipe is obtained; a first pipe and a second pipe are obtained through extrusion process molding, the first pipe is connected to the outer side of the first constant-diameter section in a sleeving mode, the second pipe is connected to the outer side of the second constant-diameter section in a sleeving mode, and the two ends of the conical pipe abut against the first pipe and the second pipe correspondingly; and obtaining a first heat shrink tube, sleeving the outer side of the core rod with the first heat shrink tube, and detaching the first heat shrink tube after the first heat shrink tube is subjected to heat shrink molding in place. According to the invention, the manufacturing efficiency and yield of products can be improved.

The invention discloses a cadmium telluride crystal preparation cooling device and a using method thereof.The cadmium telluride crystal preparation cooling device comprises a mounting supporting plate, a feeding mechanism is arranged on the front surface of the mounting supporting plate, a cooling mechanism is arranged at one end of the front side of the mounting supporting plate, the feeding mechanism comprises a moving rail, the moving rail is arranged on the front surface of the mounting supporting plate, and the moving rail is arranged on the front side of the mounting supporting plate. A limiting cavity is formed in the middle of the inner side of the moving track, a moving gear rolls on the inner side of the moving track, a moving plate is rotationally connected to one side of the moving gear, a fixing disc is arranged in the middle of the other side of the moving gear, and four guide column blocks are evenly fixed to the outer surface of one side of the fixing disc. The cadmium telluride crystal cooling device has the beneficial effects that cadmium telluride crystals can be conveniently and vertically pushed into the cooling cabin in a circulating mode, the feeding effect can be improved, the cadmium telluride crystals can be conveniently cooled in a stepped mode, large structural defects of the rapid cooling surfaces of the cadmium telluride crystals can be prevented, and the cooling effect of the cadmium telluride crystals is improved.

The invention discloses microcapsule self-regeneration-based long-acting formaldehyde-removing cement and a preparation method thereof, and belongs to the field of building materials and environmental functional materials. The material is composed of Portland cement clinker and a functional composite additive, wherein the additive comprises Zn < 2 + > modified zeolite, a manganese-based catalyst, a pH-responsive sustained-release microcapsule and alpha-semi-hydrated gypsum. According to the invention, through the cooperation of zeolite selective adsorption, non-photocatalytic oxidation of the manganese-based catalyst in an alkaline environment and pH-triggered microcapsule self-regeneration, an adsorption-catalysis-regeneration function closed loop is formed, efficient and lasting removal of formaldehyde under a dark condition is realized, and the mechanical properties of a cement matrix are not damaged. According to the preparation method, the functional components are pre-compounded and then co-ground with the cement clinker, the process is simple, and the preparation method is suitable for industrial production.

The invention relates to a double half-Heusler alloy thermoelectric material with low lattice thermal conductivity and a preparation method thereof, the thermoelectric material is any one of a p-type thermoelectric material or an n-type thermoelectric material, the chemical formula of the p-type thermoelectric material is Sc0. 6V0. 5Co1-xNixSb, x is more than or equal to 0 and less than or equal to 0.12, and the n-type thermoelectric material is one of Sc0. 6V0. 5Co1-xNixSb. The chemical formula of the n-type thermoelectric material is Sc0. 5V0. 6Co1-yNiySb, wherein y is greater than or equal to 0 and less than or equal to 0.30. The preparation method comprises the following steps: mixing Sc, V, Co, Ni and Sb, grinding, sequentially carrying out sintering and vacuum packaging treatment to obtain a thermoelectric material wafer, and carrying out high-temperature annealing treatment on the thermoelectric material wafer to obtain the double half-Heusler alloy thermoelectric material with low lattice thermal conductivity. Compared with the prior art, the method has the advantages that the prepared double half-Heusler alloy thermoelectric material is replaced by the heterovalent elements, the Sc / V ratio is accurately regulated and controlled, p-type and n-type thermoelectric materials based on the same parent compound are successfully obtained, and the two materials both show promising thermoelectric performance.

The application provides a concentrated winding circulating current loss suppression method and structure based on coil cross transposition, and belongs to the technical field of motor winding design and concentrated winding loss optimization. The structure comprises a spliced stator core and a winding coil. The winding coil is formed by winding a plurality of parallel winding strands around the split teeth in a root-by-root manner. Each parallel winding strand is arranged in layers in order from inside to outside. The winding coil is provided with a selective cross transposition structure at the end according to the parity of the number of parallel winding strands. The odd number of strands are only provided with an inter-coil cross transposition structure, and the even number of strands are provided with an inter-coil cross transposition structure or an intra-coil cross transposition structure. When the application is applied to a high-speed fractional-slot concentrated winding permanent magnet motor, the circulating current loss coefficient can be reduced by more than 36.4% at a frequency of 1500 Hz, the process is simplified, the end space occupation is reduced, and the motor power density is improved.

The invention discloses nanometer graphene oxide and a preparation method thereof. The transverse size of the nanometer graphene oxide is 10-100 nm, and the thickness of the nanometer graphene oxide is 1-2.5 nm. The surface chemical structure meets the following conditions: a C1s peak is analyzed on the basis of X-ray photoelectron spectroscopy, the sum of the atomic percent content of hydroxyl and epoxy groups is not higher than 15%, and the atomic percent content of carboxyl is not lower than 6%. According to the structural design, the structural defect caused by excessive oxidation or reduction in a traditional method is avoided, and the chemical stability and the functionalization potential of the material are improved.

The invention relates to the technical field of nano materials, in particular to a preparation method of a Zn-based bimetal MOFs material and application of the Zn-based bimetal MOFs material as a medical drug carrying material. The preparation method comprises the following steps: preparing Zn, Mn and a ligand according to a molar ratio of 1: 1: (72-80), and mainly comprises the steps of preparation of metal salt solutions, coordination polymerization reaction, separation and purification, and drying. The process for preparing the Zn-based bimetallic MOFs material is simple and environmentally friendly, the obtained product has the excellent performance of being small in particle size, regular and stable, and the material loaded with doxorubicin hydrochloride has high loading rate and has potential clinical conversion value.

This invention discloses a beam formwork installation and reinforcement device for confined spaces, comprising a disc-lock frame. An aluminum alloy beam bottom horizontal plate is mounted on top of the disc-lock frame, and a beam bottom support formwork is installed above it. A first timber beam is installed between the two. The inner side of the formwork is a concrete beam with integrated columns. Irregularly shaped metal rods with steel plates and clearance grooves are installed on the outer sides of the formwork on both sides of the columns. These irregularly shaped metal rods are connected by a connecting assembly. A second timber beam is installed between the two columns, with both ends contacting small channel steel. L-shaped fixing clips are fixed to the small channel steel. The connecting assembly replaces the original first nut with an end assembly, which includes a magnetic end plate, a square-section threaded sleeve, and a limiting nut. This invention adapts to confined space layouts through a modular aluminum alloy beam bottom horizontal plate and achieves precise reinforcement of the beam formwork while being suitable for operation in confined spaces using irregularly shaped metal rods with clearance grooves and a connecting assembly containing end assemblies.

The invention discloses an efficient environment-friendly curing agent for marine soft soil and a preparation method and application thereof, and belongs to the technical field of soft soil curing. The salt-resistant concrete comprises the following components in percentage by mass: 55%-70% of a core gel system, 8%-15% of a composite excitation system, 5%-10% of a salt-resistant modification system and 10%-20% of a reinforced filling system, the core gelling system is composed of steel slag micro powder, slag powder and desulfurized gypsum; the composite excitation system is composed of modified fly ash and a composite alkali activator; the salt-resistant modification system is composed of a chitosan grafted acrylamide copolymer and zeolite powder; the reinforced filling system is composed of polypropylene fibers, nano calcium carbonate and construction waste regenerated micro powder. The curing agent is a special curing agent system for marine soft soil with strong adaptability, high curing efficiency, good durability and essential environmental protection.

The invention belongs to the technical field related to alloy manufacturing, and discloses a sintering device for improving material temperature uniformity and application and a design method thereof, the sintering device comprises a reaction furnace body and a temperature regulation and control unit, and the reaction furnace body comprises a reaction cavity and a furnace door; the temperature regulation and control unit comprises heating structures, the heating structures are arranged on the left side and the right side in the reaction cavity correspondingly, the heating structure on any side is arranged in the front-back direction, and the heating structure on any side is sequentially divided into a front heating section, a middle heating section and a rear heating section from front to back; the arrangement density of the heating structures in the middle heating section is smaller than the arrangement density of the heating structures in the front heating section and the arrangement density of the heating structures in the rear heating section. By adjusting the setting density of the heating structure in the reaction cavity in different areas, the materials in the reaction cavity are heated in a centralized manner, the temperature uniformity of the materials during heating and sintering is improved, and structural defects caused by non-uniform heating are effectively prevented.

The application discloses a high-strength light-weight silt-based ecological slope protection block compression molding equipment, and belongs to the technical field of slope protection block production. The equipment comprises a rack, an upper mold arranged in the rack, connecting mechanisms arranged at both ends of the upper mold, and a lower mold plate arranged at the bottom end of the upper mold. The upper mold is installed on the rack through the connecting mechanisms, and the upper mold is provided with an opening at the lower end. The lower mold plate is arranged at the bottom end of the upper mold, and a mold cavity is formed between the lower mold plate and the upper mold. A demolding mechanism is arranged on the rack and connected with the lower mold plate to assist in separating the lower mold plate from the upper mold. The inner wall of the upper mold is provided with a Teflon coating, and the upper mold is provided with a material injection mechanism. The vertical rod and the lower mold plate are pulled down through a hydraulic rod, so that the lower mold plate is separated from the upper mold. The device can assist in separating the block in the mold cavity, manual separation is not needed, the demolding action is continuous, and the demolding time is significantly shortened. The automatic demolding reduces the manual operation link, reduces the dependence on skilled workers, and saves the labor cost.

This invention relates to the field of medical polymer materials technology, and discloses an injectable polymer hydrogel and its preparation process. The hydrogel is prepared by in-situ crosslinking of solution A and solution B at a volume ratio of 1:1. Solution A includes oxidized dextran, zinc gluconate, anhydrous betaine, and phosphate buffer, while solution B includes carboxymethyl chitosan and phosphate buffer. This invention utilizes oxidized dextran and carboxymethyl chitosan to construct Schiff base covalent crosslinks, and introduces zinc gluconate to provide delayed metal coordination crosslinks, forming a double crosslinked network; simultaneously, anhydrous betaine is used to construct a hydration shield within the network. This invention effectively solves the problems of needle blockage caused by excessively rapid gelation time in traditional in-situ hydrogels and excessive swelling after implantation, achieving controllable gelation time, stable osmotic pressure, and uniform internal network, exhibiting excellent clinical operability and structural stability.

The application discloses a production method of Ebonite rubber roller based on temperature and pressure intelligent regulation and control, and relates to the technical field of rubber roller production, and comprises the following steps: constructing a temperature collection credibility function according to a local temperature abnormal distribution matrix, fitting and comparing a temperature response of each collection point with a target temperature rising curve, generating a credibility index for judging the credibility of temperature data, and correcting the judgment logic of temperature collection according to the local temperature abnormal change caused by abnormal heat conduction due to air block in the vulcanization temperature rising process. The application solves the problem of temperature control misjudgment caused by local heat conduction abnormality due to air block in the vulcanization temperature rising process of the Ebonite rubber roller, realizes dynamic identification and self-adaptive regulation and control of temperature and pressure abnormality, ensures sufficient vulcanization, uniform structure and stable performance of each area of the rubber roller, and improves product quality and service reliability.

The invention belongs to a construction method of a concrete guardrail with an anti-collision device. First, second and third calibration vertical supporting steel bars are arranged through a positioning scale rack; three pieces of horizontal square steel are horizontally placed on transition sections between the calibration vertical supporting steel bars respectively and are bound and fixed to the first calibration vertical supporting steel bar, the second calibration vertical supporting steel bar and the third calibration vertical supporting steel bar of the corresponding parts through iron wires, and three pieces of benchmark horizontal square steel are formed; and by taking the horizontal square steel of the three marker posts as calibration objects and referring to the pre-arranged steel bars on the two sides of the bridge deck slab in the section, positioning of the vertical supporting steel bars welded to the middle position of the section and welding and fixing of the vertical supporting steel bars and the pre-arranged steel bars at the corresponding positions are completed. The construction speed and quality can be effectively improved, operation is easy during construction, practicability is high, the effect is obvious, the construction speed is high, and time and labor are saved.

The present application relates to the technical field of gas separation membrane, and particularly relates to a polyimide hollow fiber membrane preparation method for oxygen-nitrogen separation; aromatic dianhydride and diamine are first polymerized at low temperature in N-methylpyrrolidone to prepare a polyamide acid solution, polyvinylpyrrolidone pore-forming additives and polyethylene glycol rheological modifiers are added, and the solution is stirred and vacuum degassed to obtain a spinning dope; then the dope is moved into a spinning kettle, extruded through a hollow spinneret, and simultaneously fed with a core liquid, and then drawn and washed to obtain a nascent hollow fiber membrane; then the nascent membrane is wound and collected, washed with deionized water, and dried at room temperature; the dried nascent membrane is heat treated to completely heat imidize the polyamide acid and form a stable polyimide structure; finally, the membrane is drawn, shaped, and wound to obtain a finished product; through the above method, the spinning solution, spinning process and heat imidization process can be controlled, structural defects of the membrane filament are avoided, the compactness of the polyimide structure is improved, and the application requirements are met.

The invention provides a square fiber multifilament rod, an arrangement method, an arrangement device and application of the square fiber multifilament rod. The method comprises the following steps: putting qualified square fiber monofilaments into an arrangement mold with a square inner contour of a radial section; an included angle of 45 degrees is formed between the inner side surface and the horizontal plane; the square fiber monofilaments are parallel to the axis; enabling the arrangement mold to vibrate, and automatically adjusting the positions of the square fiber monofilaments in the arrangement mold under the vibration condition to form an interlayer meshing structure; and an interlayer meshing structure is monitored on line, and after a preset arrangement standard is reached, the rod is bundled, and the square fiber multifilament rod is obtained. The technical problem to be solved is how to prepare the square fiber multifilament rod, so that square fiber monofilaments forming the square fiber multifilament rod are arranged more regularly and orderly, the structural defects of sliding dislocation, malposition, square fiber torsion and the like are effectively reduced, the quality and performance of MPO are guaranteed, the rod arrangement efficiency is improved, and the overall distortion rate of MPO is reduced.

The invention discloses a method for preparing high-thermal-conductivity aluminum nitride ceramic by utilizing graphite to induce liquid-phase oriented migration. According to the method, aluminum nitride powder is used as a matrix raw material, yttrium oxide is used as a sintering aid, crystalline nano-graphite is used as an active regulating agent, and the high-thermal-conductivity aluminum nitride ceramic is prepared through tape casting, controllable glue discharging and atmosphere sintering processes. According to the method, the crystalline-state nano-graphite initiates a carbon thermal reduction reaction, a grain boundary phase is driven to evolve along a path of YAG-YAM-Y2O3-YN, an oxidation chemical potential gradient is established to induce directional migration of a yttrium-rich liquid phase, deep purification of crystal lattices and construction of a low-phonon scattering communication framework are achieved, and meanwhile, the deoxidization efficiency and the densification behavior are balanced. The maximum thermal conductivity of the aluminum nitride ceramic prepared by the method can reach 192.5 W.m <-1 >. K <-1 >, the maximum bending strength can reach 528 MPa, and the aluminum nitride ceramic has excellent thermal and mechanical properties and can be widely applied to core substrates of high-power electronic devices, 5G base stations, high-power LED thermal management systems and the like.

The invention relates to the technical field of high-purity manganese preparation, and discloses a high-purity manganese preparation method using high and low vacuum, which comprises the following steps: S0, pretreatment operation: before pickling operation, carrying out mechanical polishing or sand blasting treatment on a manganese sheet to remove oxides and impurity layers on the surface; the method comprises the following steps: S1, pickling operation: carrying out pickling on a manganese sheet with the purity of 2N by using 0.5-10% dilute sulfuric acid under an ultrasonic condition through cleaning equipment; s2, washing and drying: washing the manganese sheet subjected to acid washing in the step S1 with pure water through cleaning equipment under an ultrasonic condition, and transferring the manganese sheet into a vacuum drying oven for drying after the pure water washing is completed; and S3, high-vacuum smelting is conducted, specifically, manganese sheets obtained through washing and drying in the step S2 are loaded into a suspension smelting furnace, smelting is conducted under the high-vacuum condition, high-purity hydrogen is introduced, the manganese solution is subjected to hydrogen treatment, and oxides and hydrides which are difficult to volatilize are removed. High-purity hydrogen is introduced for treatment under a high-vacuum condition, and a low-vacuum pulling technology is combined, so that impurities are effectively removed, and the purity of a finished product is improved.

The invention provides a preparation method and application of a high-barrier polysaccharide polymer film based on freeze dehydration rate control. The method comprises the following steps: firstly, preparing a water-soluble polysaccharide polymer-based aqueous solution; thirdly, taking the aqueous solution system obtained in the first step as a precursor solution, adding sulfuric acid to promote gelation and casting to form a film, and then carrying out circulating freeze thawing treatment; and the polysaccharide polymer film with high water vapor barrier property is prepared by controlling the dehydration rate in the freezing process in the circulating freezing and thawing process. The dehydration rate in the freezing process is controlled, so that the polymer solution strengthens the compactness of the film and formation of a lamellar structure in the circulating freezing and thawing process, more structure defects are avoided, and the water vapor barrier property of the film is remarkably improved. Besides, the preparation process and the required materials are simple, convenient and feasible, the environmental protection requirement is met, and the preparation process is subjected to accurate quantitative design, fine regulation and optimization, so that the obtained polysaccharide polymer-based film has excellent water vapor barrier property and high practicability, and has wide development potential in the field of barrier packaging.

The application discloses a kind of polybenzodifuranone and its constant potential polymerization preparation method, belong to organic conductive polymer material preparation technical field, benzodifuranone (BFDO) and supporting electrolyte are dissolved in polar aprotic solvent, and electrolyte is obtained by mixing uniformly;With platinum metal electrode as working electrode and counter electrode, with saturated calomel electrode as reference electrode, three electrodes are connected with direct current power supply and are placed in the electrolyte, in air atmosphere, electrochemical polymerization reaction is carried out using constant potential method;After reaction, the reaction liquid is extracted and filtered, dried, to obtain polybenzodifuranone (PBFDO).The application uses constant potential electrochemical polymerization method, n-type conductive polymer polybenzodifuranone can be synthesized in air atmosphere in one step, without catalyst, high-temperature anaerobic environment and complex post-processing, the product conductivity is 1.157-18.28 S / cm.Process simplification, low cost, process controllable, can realize green scale preparation and industrialization application.

The utility model belongs to the technical field of mills, and discloses a mold for an angle lining of a mill. The mold comprises a hot plate, a bottom mold and a mold cover, a plurality of limiting pieces are arranged on the hot plate; the bottom die is placed on the hot plate, and the limiting pieces are arranged on the periphery of the bottom die at intervals so as to limit the position of the bottom die. The bottom die comprises an insert and a frame, the insert corresponds to the angle lining to be machined in shape and size, and the frame is fixedly arranged on the insert in a matched and sleeved mode; a plurality of glue injection grooves, a plurality of glue injection holes, a plurality of overflow grooves and a plurality of overflow holes are formed in the mold cover; the glue injection hole is formed in the glue injection groove, and the overflow hole is formed in the overflow groove; wherein before glue filling, the mold cover and the bottom mold are closed and fixed, and the glue injection hole is located under the glue injection head. When the angle lining is processed, the die is not damaged, and the appearance integrity of an angle lining product is ensured.

The application discloses a sludge brick blank drying method and relates to the technical field of drying. The method comprises the following steps: obtaining a surface evaporation rate and an internal moisture migration rate in a brick blank drying process; comparing the two rates with a preset matching relation algorithm; adjusting and controlling drying conditions according to a comparison result to make the two rates tend to match; and starting a fault-tolerant mechanism to maintain the drying process when data is abnormal or the adjustment and control fails. The application can solve product quality problems caused by the fact that the surface evaporation rate and the internal moisture migration rate do not match in the drying process.

The application discloses a carbon fiber front machine cover decoration piece forming die and a forming method, and relates to the technical field of carbon fiber forming die and forming method. The forming base is sequentially provided with two independent sealing cavities from inside to outside; the two independent sealing cavities are respectively an independent part forming vacuum cavity and a buffer pressure stabilizing vacuum cavity; the differential pressure linkage control mechanism matches the rheological characteristics of carbon fiber prepreg resin, and independently controls vacuumizing, pressure maintaining and pressure releasing of the part forming vacuum cavity and the buffer pressure stabilizing vacuum cavity according to forming process stages, so as to adapt to the forming process of differential pressure exhaust, temperature control compaction and segmented curing. The whole forming die and process can be completely adapted to conventional ordinary oven equipment, and the dependence on high-end autoclave equipment is abandoned. Meanwhile, through structural innovation and process fine control, the short board of poor quality and low yield of traditional oven forming process is solved, and high-precision and low-defect forming effect under low-cost production conditions is realized.

The invention relates to a novel quaternary alloy core-shell quantum dot and a preparation method thereof, CdZnSeS is adopted as a core, a ZnxCd1-xSeyS1-y transition layer is introduced, and ZnS is adopted as a shell layer, so that a quaternary alloy core-shell structure is formed. A temperature increasing growth strategy is adopted, and parameters such as the proportion, the dropwise adding sequence, the dropwise adding speed and the reaction temperature of a precursor solution are controlled, so that the prepared quantum dot not only reduces the use of a Cd element, reduces the environmental risk and the biotoxicity, but also improves the stability and the fluorescence efficiency on the premise of ensuring the high yield. The specific preparation method comprises the following steps: respectively preparing precursor solutions containing a cadmium source, a zinc source, a sulfur source, a selenium source and the like, and reacting according to a specific sequence and conditions to form a quantum dot core, a transition layer and a shell layer. In addition, by adjusting the component proportion and controlling the temperature, adjustment of the light emitting wavelength of the quantum dots and optimization of the performance are achieved, the problem that the quantum dots are unstable in practical application is solved, and wide application prospects are achieved.

The invention discloses a preparation method of a transistor, a transistor array and electronic equipment, and relates to the technical field of semiconductors. The method comprises the following steps: sequentially stacking a first silicon film layer, a germanium-silicon film layer and a second silicon film layer on a silicon substrate; generating bit lines on the silicon substrate, the first silicon film layer, the germanium-silicon film layer and the second silicon film layer along the bit line direction; etching along the word line direction to form a second etching groove, and generating an epitaxial silicon material on the surface of the silicon column formed by the first etching groove and the second etching groove; filling a silicon dielectric material, and etching the silicon column into at least two sub-silicon columns; and epitaxial silicon materials are generated in the areas, not covered by the silicon dielectric materials, of the at least two sub-silicon columns, and the vertical grid full-surrounding transistor is obtained after the grid materials are filled to form word lines. The epitaxial silicon material is formed on the two sides of the germanium-silicon film layer twice to serve as the channel, so that the symmetry of the formation of the channel is improved relative to a transistor unit, and the performance of the transistor is improved.

The utility model belongs to the technical field of medical instruments, and discloses an external locking type catheter fixing device which comprises a fixing part and a rotating part, a strake is arranged between the fixing part and the rotating part, and the middle of the strake keeps horizontally bent in the radial direction under the action of elasticity of the strake. A locking mechanism is arranged between the fixed part and the rotating part; a convex-concave structure is arranged on the circumferential surface of the rotating part, a spring piece is arranged on the fixed part, the spring piece abuts against the circumferential surface of the rotating part under the elastic effect, the spring piece is provided with a matching structure interacting with the convex-concave structure, and the spring piece and the convex-concave structure are combined to form the locking mechanism. The locking mechanism adopted by the utility model is not provided with an independent part and does not need to be additionally assembled, and when the rotating part is mounted on the fixed part, only the leaf spring needs to be moved to avoid the rotating part, so that the rotating part is more convenient to mount.

This invention relates to the field of piezoelectric ceramics technology, specifically to a method for preparing low acoustic impedance BT piezoelectric ceramics and their materials. The method includes: Step S1, molding a raw material mixture containing BT powder and a sacrificial pore-forming agent to obtain a green body; Step S2, preheating and holding the green body to remove volatiles; Step S3, degreasing the preheated green body under an oxygen-rich atmosphere to form a uniform fine-pore structure within the green body; Step S4, sintering the degreased green body to obtain the low acoustic impedance BT piezoelectric ceramic material. In this application, by burning off the sacrificial pore-forming agent under an oxygen-rich atmosphere, uniform fine pores are formed inside the piezoelectric ceramic, thus solving the problem that traditional pore-forming techniques in the prior art cannot form a uniform and regular fine-pore structure in the ceramic green body.

The present invention discloses a stent tube for use in ureteral end-to-side anastomosis, comprising a single-J tube, a transition joint being arranged at one end of the single-J tube, an inlet being arranged at the upper end of the transition joint, and two outwardly protruding outlets being symmetrically arranged and connected to the inlet being arranged at the lower end, a mounting groove being arranged at the lower end of the transition joint between the two outlets, a spring sheet being embedded in the mounting groove, the upper end of the spring sheet being matched with the mounting groove, and two independent positioning spring sheets extending from the lower end, two hoses being respectively connected to the two outlets, slots being arranged at opposite sides of the two hoses, and two positioning spring sheets being respectively matched with corresponding slots, and when the two positioning spring sheets are both located at the first station, the two positioning spring sheets are parallel to each other, and when the two positioning spring sheets are located at the second station, the two positioning spring sheets are respectively bent outwards.