119results about How to "Strong anchoring force" patented technology

The invention discloses a silane coupling agent modified polycarboxylate superplasticizer and a preparation method thereof, belonging to the field of cement additives. The preparation method comprises the following steps: adding a certain amount of acrylic acid into a polyether macromonomer solution, and stirring uniformly; adding a double bond-containing silane coupling agent; stirring the solution to a clear state and continuously stirring; adding an oxidizing agent, an initiator solution and a small monomer solution while keeping the stirring state; after the stirring, curing for 1-2h; adding liquid caustic soda for neutralization and stabilizing the pH value at 6; and adding a silane coupling agent without double bond to obtain a finished product of silane coupling agent modified polycarboxylate superplasticizer. In the invention, a functional group with a siloxane structure is introduced into the main chain of polycarboxylate molecule, and an anchoring ability in chemical bonding strong interaction with cementing material particles is provided for the branch chain of the comb-shaped polycarboxylate superplasticizer; and with the increase of the anchoring ability, the adaptability and slump loss resistance of the superplasticizer can be remarkably enhanced, and the application of the superplasticizer in the field of mineral micropowder dispersion is expanded to a certain degree.

Provided is a solvent for forming an alignment film capable of fabricating a liquid crystal alignment film having high quality, an improved imidization ratio, large surface anisotropy, and a strong anchoring force. The solvent for forming an alignment film including a polymer for a liquid crystal display includes the polymer of the alignment film including polyimide and a variable compound capable of changing a chemical structure for evaporating after imidizing and sintering, which is in a liquid state during a film-forming process of coating, imidizing, and sintering polyamic acid which is a precursor of polyimide.

The invention provides a shear type expansion anchor rod which can be effectively applied to anchoring or reinforcing or fixing of loose and unstable layers in the engineering of tunnels, slope protection, foundation pits, dams, exploitation and the like, and an application method thereof. The shear type expansion anchor rod comprises a lug-containing nut support the upper part of which is hinged with expansion plates, and a screw rod matched with the lug-containing nut support, wherein the top end part of the screw rod is a cambered surface or semispherical head; the cambered surface or semispherical head on the top end part of the screw rod is contacted with the inner side corner of a bevel plane on the lower end part of each expansion plate; the inner side corner of the bevel plane on the lower end part of each expansion plate can be directly driven to continuously push each expansion plate to strut in a shear form towards an outer side by rotating the screw rod; a support plate and a nut matched with the support plate are sleeved at the lower end of the screw rod. The shear type expansion anchor rod has the advantages of simple and skilful structure, easiness in machining and manufacturing, convenience and reliability in use and low machining cost.

The invention provides a shear type expansion anchor rod which comprises a fixing part, a pushing part and a tightening part, wherein the fixing part is provided with an expansion part. The shear type expansion anchor rod is characterized in that the pushing part is matched with the fixing part, the pushing part and the fixing part can move along the coaxial direction of the axis of the fixing part, the expansion part is hinged with the top end portion of the fixing part, the lower end portion of the expansion part is provided with an inclined surface facing the pushing part, the top end portion of the pushing part can contact with the inclined surface of the lower end portion of the expansion part and pushes the expansion part along the inclined surface, the expansion part is stretched in a shear mode towards the outer side of the pushing part, and the tightening part is arranged at the lower end of the pushing part and can move in the coaxial direction of the axis of the pushing part. The shear type expansion anchor rod is simple and ingenious in structure, the expansion part is stretched in the shear mode, the stretched range is large, anchoring force is strong, and the shear type expansion anchor rod not only is used for surrounding rock support and protection, but also is widely suitable for anchoring or fixation of mines, tunnels, protection slops, foundation trenches, buildings and other engineering. Extension application comprises underpinnings for constructing the buildings, stand columns for highway sides, and the like, and safety, reliability and universal values of the shear type expansion anchor rod are achieved really.

A liquid crystal aligning agent which can provide liquid crystal aligning capability through exposure to polarized radiation without rubbing and which is used to form a liquid crystal alignment film, a method of forming a liquid crystal alignment film, and a liquid crystal display element having this liquid crystal alignment film. An alignment film is formed from a liquid crystal aligning agent containing a polymer having a polyamic acid ester structure with a conjugated enone structure in the side chain and applying radiation to it from a predetermined direction. Thereby, a liquid crystal display element having high thermal stability in the alignment of liquid crystals and excellent display characteristics can be manufactured.

The invention relates to the technical field of tunnel and underground construction anchoring equipment, in particular to a self-propelled hollow slip casting anchor rod with a stress-measuring function and an operating method. The self-propelled hollow slip casting anchor rod with the stress-measuring function includes a rod body with a hollow structure, a self-propelled drill is connected at thefront end of the rod body, and the back end of the rod body is provided with a slip casting opening which communicates with an inner cavity of the rod body; and the rod body is further provided witha stress-measuring device and an anchoring structure which is close to the self-propelled drill. According to the self-propelled hollow slip casting anchor rod with the stress-measuring function, thestress-measuring device is arranged to combine the processes of drilling, anchoring and slip casting into the same construction process, and the anchoring can be achieved in short time; and stress conditions of all sections of the anchoring rod in the supporting process can be monitored, so that the supporting mechanism of action and the stress conditions of the anchoring rod under the various kinds of surrounding rock conditions can be known, and critical evidences and references are supplied to the research of design parameters for the anchoring rod, improvement of the construction techniqueand the surrounding rock failure mechanism.

The invention discloses a self-balance anchor counter weight broken pile forced landing rectification method. The self-balance anchor counter weight broken pile forced landing rectification method comprises the following steps of: drilling an anchor rod hole in a foundation pile planned to be truncated; taking the position planned to be truncated as a boundary; taking a lower-part pile body as an anchoring section, an upper-part anchor hole as a free section and a bearing platform which needs to be rectified as an outer anchor bed to form a self-balance anchor; cooperating with various traditional direct broken pile technologies, or artificially arranging a base pile section weakening section on a pile end; buckling the pile body concrete of the section weakening section under the joint action of the upper-part load self weight and the self-balance anchor counter weight to realize the broke pile; realizing the counter weight broken pile forced landing rectification; rectifying building and structure inclination caused by the uneven sedimentation of the pile foundation. According to the self-balance anchor counter weight broken pile forced landing rectification method disclosed by the invention, the self-balance anchor used for assisting the counter weight directly adopts the lower-part pile body of the foundation pile as the anchor rod anchoring section to provide anchoring counter force, the counter weight problem of broken pile forced landing is solved by the ingenious economic means, and therefore the broken pile forced landing can be safer and controllable. According to the self-balance anchor counter weight broken pile forced landing rectification method disclosed by the invention, change and disturbance on the stressed system and the foundation of the building and the structure can be avoided, and the building and the structure can be more safely used after being rectified.

The invention discloses a super-long super slow release type polycarboxylic acid slump-retaining agent master batch suitable for projects such as hydraulic tunnels, railway tunnels, metros and underground oil and gas delivery adopting concrete having the capability of retaining slump for 4-6 hours under the conditions of hot weather and long distance. Limited by 40% of the mass percent of mother liquid, the total mass of synthesized raw materials is 1000 parts, the usage amount proportion is that the usage amount of polyether macromonomer accounts for 325-335 parts, the usage amount of unsaturated carboxylic acid micro-monomer accounts for 10.0-18.0 parts, the usage amount of acrylic hydroxyalkanoate accounts for 35.0-45.0 parts, the usage amount of crosslinking monomer accounts for 5.0-10.0 parts, the usage amount of sulfonic acid type chain transfer agent accounts for 2.0-5.0 parts, the usage amount of hydrogen peroxide accounts for 2.0-3.5 parts, the usage amount of vitamin C accounts for 0.60-0.90 part, the usage amount of caustic soda liquid accounts for 7-10 parts, and the balance is water. The polycarboxylic acid slump-retaining agent is moderate in molecular weight, can be independently used or compounded with other polycarboxylic acid water reducing agents for usage, can remarkably improve the indexes such as slump-retaining property, cohesiveness and flowing retention ability of newly mixed concrete in 6 hours.

The present invention relates to a quick-hardening high-strength cement anchoring agent. It adopts quick-hardening sulfo-aluminite cement clinker as basic gelation material, and adds hemihydrate plaster and quicklime as excitation agent to accelerate hydration process so as to implement quick setting up and can make compression strength and bending strength quickly increase. Said invention has microexpansion property, three-day free expansion rate is greater than 0.3%, and said product solidification speed is quick, its primary solidification is greater than 5 min, and the end solidification is less than 15 min. and its product anchoring strength also can be quickly raised.

The invention discloses anti-mud polycarboxylate water reducing agent masterbatch with mono-di-alkyl phosphate branches. The masterbatch is used for higher-content clay minerals in gravel materials. The masterbatch shows characteristics of not low initial water reduction rate, good slump retaining property in the medium and late stages and good overall stability. In terms of 1000 parts of the total mass of the synthesis raw materials, 40% in percentage by mass, as the limit, of the masterbatch comprises the raw materials as follows: 350-360 parts of polyether macromonomers, 32.0-38.0 parts of acrylic acid, 2.0-6.0 parts of mono-di-alkyl phosphate, 1.0-5.0 parts of a phosphate chain transfer agent, 0.5-1.0 part of mercaptoacetic acid, 3.0-6.0 parts of hydrogen peroxide, 0.5-0.8 parts of vitamin C, 7-15 parts of liquid alkali and the balance of water. A synthesized polycarboxylate water reducing agent has large molecular weight and longer main chain, comprises long and short staggered branches, and is high in density, high in slump retaining property and wide in adaptability.

The invention discloses a foundation pile-anchor supporting system for a close existing underground structure and a construction method of the system. The supporting system comprises front-row steel pipe piles, rear-row steel pipe piles, rear-row vertical prestressed anchors, a front-row pile top beam, a rear-row pile top beam, transverse connecting reinforcements, front-row anchorages, rear-row anchorages, cushion blocks, tapered iron pieces, front-row prestressed anchors and wales. Through the vertical prestressed anchors arranged in the rear-row steel pipe piles, occupancy in underground space can be reduced greatly, and limited ground surface and space within building lines are fully utilized. The vertical prestressed anchors are anchored to the good ground, usage of the rear-row steel pipe piles can be reduced greatly, good anchorage force is provided, the front-row prestressed anchors are used for anchoring and stabilizing the rock stratum, and overturning resistance of the overall structure is improved. By the aid of the rear-row vertical prestressed anchors and the prestressed anchors arranged in the front-row steel pipe piles, factor of safety against overturning of the supporting system is enhanced effectively, construction cost is lowered, and construction period is shortened.

The invention relates to a shuttle-shaped contracted type anchor structure and a using method thereof, and belongs to the technical field of slope supporting and pile foundation anchoring. The shuttle-shaped contracted type anchor structure comprises an anchor rod body, a sleeve and a plurality of shuttle arms, one end of the anchor rod body is provided with a threaded portion, the threaded portion is connected with a nut, the other end of the anchor rod body is sleeved with a first ring, the anchor rod body passes through the sleeve, the sleeve comprises a perforated steel plate, a hollow tube and a second ring, one end of the hollow tube is connected with the perforated steel plate, and the other end of the hollow tube and the second ring; and the second ring is arranged on the side close to the first ring, the perforated steel plate is arranged on the side away from the first ring, one end of each shuttle arm is connected to the first ring, and the other end of the shuttle arm is connected with the second ring. By means of the shuttle-shaped contracted type anchor structure and the using method thereof, recycling is achieved, grouting is not needed, direct contact with a rock and soil body is carried out, the manufacturing manner and the operation mode are simple, construction is easy, and the anchoring force is large.

The invention discloses a styrene-maleic anhydride structure containing and graft-modified water-based pigment dispersant and a preparation method thereof. After a segmented copolymer is formed by using four monomers of styrene, a styrene derivative, maleic anhydride and an acrylic acid derivative to carry out free radical copolymerization, and the segmented copolymer is graft-modified by using agraft modifier to prepare the styrene-maleic anhydride structure containing and graft-modified water-based pigment dispersant. The styrene-maleic anhydride structure containing and graft-modified water-based pigment dispersant disclosed by the invention has the advantages that the steric hindrance is high, the anchoring capacity is high, a pigment can be stably dispersed in the water-based colourpaste application, the relative color strength is high, and the storage stability is higher.

Provided is a method of manufacturing new liquid crystal display device according to an embodiment of the present invention. Firstly, an alignment film is formed on a substrate. The alignment film is divided into a first alignment film formed using, as a precursor, liquid-state polyimide that contains a photodecomposition substance and a second alignment film formed using, as a precursor, a polyamic acid that does not contain a photodecomposition substance. UV light is irradiated to the alignment film, and decomposed substances formed by irradiation of the UV light is removed by an at least two-step removing process. By the method of manufacturing a liquid crystal display device according to the exemplary embodiment of the present disclosure, bright spots are minimized in pixels and a brightness of black is lowered, so that a liquid crystal display device with a high contrast ratio can be realized.

A monolithic ceramic electronic component includes a component body and outer electrodes. The component body includes a plurality of stacked ceramic layers and a plurality of inner electrodes which extend between the ceramic layers, which contain Ni, and which include exposed ends exposed on predetermined surfaces of the component body. The outer electrodes are electrically connected to the exposed ends of the inner electrodes and are formed on the predetermined surfaces of the component body by plating. The inner electrodes include Mg—Ni coexistence regions where Mg and Ni coexist.

The invention discloses an umbrella contraction type anti-falling anchor rod structure and a using method. The umbrella contraction type anti-falling anchor rod structure comprises an anchor rod body,a sleeve arranged outside the anchor rod body in a sleeving mode, a plurality of supporting bodies connected with the sleeve and an umbrella arm. A threaded part is arranged at the end, away from thesupporting bodies, of the anchor rod body and connected with a nut, and a first circular ring is fixed to the other end of the anchor rod body. One end of the umbrella arm is hinged to the first circular ring, one end of each supporting body is hinged to the sleeve, and the other end of each supporting body is connected with the middle of the umbrella arm through a hinge piece. The nut is screwedto push the sleeve to open the supporting bodies and the umbrella arm, and thus the umbrella arm is fully embedded into rock and soil. According to the umbrella contraction type anti-falling anchor rod structure and the using method thereof, the umbrella contraction type anti-falling anchor rod structure can be recycled and directly makes contact with the rock and soil without grouting, falling of an anchor rod is prevented, the manufacturing mode and the operation mode are simple, construction is easy, and the anchoring force is high.

The invention relates to a soft rock chamber floor heave treatment supporting structure and method based on prefabricated assembly type bottom arc plates. The supporting structure comprises a steel bracket, prefabricated assembly type bottom arc plates, anchor cables and a bottom plate waterproof layer, wherein a plurality of prefabricated assembly type bottom arc plates are assembled to form a reinforcement bottom plate, the steel bracket is supported or inserted into the prefabricated assembly type bottom arc plates at two end parts, the end parts are subjected to special treatment so as tobe exactly matched with the steel bracket, the anchor cables penetrate through the prefabricated assembly type bottom arc plates and are anchored inside surrounding rocks, the anchoring ends of the anchor cables are beyond the depth of a zero displacement marking line of the bottom plate, the depth of the zero displacement marking line is determined by matching field monitoring with theoretical analysis, and the bottom waterproof layer is laid at the inner sides of the prefabricated assembly type bottom arc plates. The supporting structure of the invention adopts a special reinforced support technology of matching the high-bearing-capacity bracket with the bottom plate, is simple in construction and economic in cost, not only reinforces the support force of the bottom plate and suppressesthe deformation of the bottom plate, but also can optimize the overall support of the roadway, thereby being capable of effectively reducing the problem of floor heave of the chamber, and reducing therepairing rate of the chamber.

The invention discloses a large-head energy gathering perforating pipe type grouting anchor rod with a ribbed steel framework. The large-head energy gathering perforating pipe type grouting anchor rod comprises four major parts including a blasting perforating device, a pipe type grouting anchor rod body, an energy gathering charging part and a steel bar framework. A construction method comprises the following steps including (1) equipment preparation; (2) measurement and hole distribution; (3) hole drilling; (4) hole cleaning and inspection; (5) blasting perforating device and anchor rod beating; (6) stemming sealing; (7) explosion initiation; (8) hole cleaning; (9) stop-grouting plug installing; (10) grouting. According to the grouting anchor rod and the construction method, thorn branches are arranged on the outer wall of the pipe type grouting anchor rod body, in addition, the blasting perforating device is welded on the bottom of the pipe type grouting anchor rod body, an explosion initiation explosive bag and the energy gathering charging part are arranged at the inside of the pipe type grouting anchor rod body, the high-intensity anchoring force can be immediately provided, the anchor rod falling is prevented, in addition, the grouting on rock and soil bodies can be realized through the tubular grouting anchor rod, and the large-end-part large-area friction can be formed, that is, a plugged novel composite anchoring and grouting reinforced integral supporting and protecting system is formed, and the reinforcing effect of the anchor rod on the rock body is greatly improved.

This is a kind of packer. The oil pipe is pressed and rubber cylinder is expanded to seal the ring space of oil sleeve. The inner cavity pressure of rubber cylinder assembly keeps constant under the action of check valve. The packer is anchored on the sleeve. After expanding, rubber cylinder assembly firmly attaches on the inner wall of sleeve and seals the ring space of oil sleeve. There is enough anchoring force between rubber cylinder and sleeve to make there is no relative movement between the packer and sleeve. Thus, sealing is firm. Since the rubber cylinder has no slips, the sleeve will not be damaged.

The invention relates to a metal-imitating ABS modified material. The metal-imitating ABS modified material consists of the following components: 70-95 parts of ABS, 0.5-10 parts of pigments, 1-5 parts of a coupling-lubricating composite modifier, 5-10 parts of a tackifier, 0-10 parts of filler and 0.1-1 part of an antioxidant, wherein the trademark of the coupling-lubricating composite modifier is YY-503, and the number-average molecular weight of the coupling-lubricating composite modifier is 3000-5000; a low melting point of the coupling-lubricating composite modifier is 75 + / - 5 DEG C, and a high melting point of the coupling-lubricating composite modifier is 150 + / - 10 DEG C; the tackifier is C5 petroleum resin with average molecular weight of 1000-2500. The metal-imitating ABS modified material can be used for overcoming the problems that weld marks are severe, the metal effects are not good and the impact strength is declined in the prior art, and has a wide application prospect in the industry of plastic products.

The invention provides a preparation method of a high carboxyl density polycarboxylic acid water reducing agent with long and short branched chains. The preparation method comprises the following steps: (1) adding 3000 molecular weight polyether macromonomers, 1200 molecular weight polyether macromonomers and water at a certain ratio in a reaction kettle, and stirring and heating until dissolving;2) controlling the temperature to 45-50 DEG C, and starting to add a certain amount of hydrogen peroxide; (3) after 5 min, sequentially starting to dropwise add a solution B and a solution A, whereinthe solution A starts to be dropwise added within 10 min after the addition of the hydrogen peroxide, the dropwise adding time of the solution A is a hours, the dropwise adding time of the solution Bis a+0.5 hours, the solution A consists of acrylic acid, unsaturated sulfonate and water at a certain ratio, and the solution B consists of ascorbic acid, a phosphate monomer, a chain transfer agentand water; and (4) after the dropwise adding is completed, maintaining temperature constant, curing for b hours, and when the temperature of the reaction solution is lower than 30 DEG C, slowly addinga certain amount of neutralizer, and supplementing water to 1000 parts, thereby obtaining the high carboxyl density polycarboxylic acid water reducing agent with long and short branched chains.

The invention discloses a novel aqueous dispersant and a preparation method thereof, and application of the novel aqueous dispersant to dispersion containing solid particles, belonging to the field ofdispersants. The novel aqueous dispersant contains a solvation chain compatible with an aqueous solvent and an anchoring group with affinity to dispersed solid particles. The solvation chain and theanchoring group are conjugated via a covalent bond. The novel aqueous dispersant is applied to dispersion containing solid particles of organic pigment, inorganic pigment, filler, graphene or metal powder. The dispersion is liquid dispersion or solid dispersion such as printing ink, paint, plastics, color paste, pesticides, and jet ink for ceramics. The novel aqueous dispersant provided by the invention is capable of improving the dispersion stability of solid particles in an aqueous medium or enhancing the application performance of a disperse system, and can reduce pollution of volatile organic solvents in the disperse system to environment.

The invention provides a blood vessel stent. The blood vessel stent comprises a stent near end, a main stent body and a stent far end which are connected in sequence, the main stent body is composed of multiple rows of open supporting units and multiple rows of open flexible units, and the open supporting units and the open flexible units are alternately arrayed; each row of the open supporting units and each row of open flexible units are integrally connected end to end, each open supporting unit is formed by connecting front ripple supporting ribs with reverse ripple supporting ribs, each open flexible unit is formed by connecting front ripple flexible ribs with reverse ripple flexible ribs, and the preset number of open supporting units and the preset number of open flexible units which are axially adjacent to the open supporting units are connected to form a composite closed loop. The two composite closed rings which are axially adjacent to each other are connected through a connection rib. The strength of the open supporting units is greater than that of the open flexible units, and the deformation capacity of the open supporting units is lower than that of the open flexible units. The blood vessel stent has more proper radical supporting force and anchoring force, and excessive extrusion to narrow patches is reduced; the blood vessel stent has more excellent flexibility and attachment performance, and poor wall attachment is avoided.

The invention relates to a seabed automatic anchoring device. The device is composed of an external centralizing shell and an internal anchor, the internal anchor comprises an upper part and a lower part, the upper part and the lower part are connected through a connecting pipe, the upper part comprises an anchoring mechanism I, and the lower part comprises an advancing mechanism, an anchoring mechanism II, a drilling mechanism and a connecting rod fixing mechanism. The anchoring mechanism is mainly composed of an anchoring block and the like. The advancing mechanism mainly comprises a sliding sleeve and the like; the drilling mechanism mainly comprises a drill bit and the like; the connecting rod fixing mechanism is mainly composed of a connecting rod driving piece and the like. The method has the beneficial effects that when drilling and anchoring are needed in the seabed, the internal anchor can start vertical drilling under the condition that no pilot hole exists; the bit pressure can be increased through hydraulic driving, and rapid drilling of the internal anchor is achieved; the mooring rope is arranged in the anchor, so that the drilling acting force of the anchor cannot be influenced; and after drilling to a specified depth, the motor is controlled to rotate reversely, so that the connecting rod is expanded to play an anchoring role, and final anchoring is achieved by matching with the anchoring mechanism I and the anchoring mechanism II.

The invention provides polymer cement waterproof slurry prepared from superfine cement, belonging to the field of building materials. The polymer cement waterproof slurry comprises powder and liquid, wherein the liquid contains 80-100 parts of styrene-acrylic emulsion, 1-3 parts of defoaming agent, 1-3 parts of preservative and 50-150 parts of water by weight; the powder contains 300-350 parts of superfine cement, 150-200 parts of calcium carbonate, 100-150 parts of quartz sand and 0.1-5 parts of aid by weight. The polymer cement waterproof slurry has the effects of avoiding the phenomenon of sand sedimentation and further densifying skeleton structures.

The invention provides a liquid crystal display device. The device comprises an upper substrate, a lower substrate, a liquid crystal layer clamped between the upper substrate and the lower substrate and first and second wire grid layers which are oppositely arranged at intervals; the upper substrate comprises a first substrate base and a color filter overlaid on the side, close to the liquid crystal layer, of the first substrate base, and the first wire grid layer is clamped between the liquid crystal layer and the color filter; the lower substrate comprises a second substrate base and a TFT layer overlaid on the side, close to the liquid crystal layer, of the second substrate base, and the second wire grid layer is clamped between the liquid crystal layer and the TFT layer; the first andsecond wire grid layers comprise polarizer units and light blocking units, and the light blocking units are inserted between the adjacent two polarizer units. Compared with the prior art, the liquid crystal display device has high display precision and low production cost.

The invention relates to an A-level flame-retardance heat-preservation decoration integration plate and a preparation method thereof. The plate comprises a facing layer, a heat preservation layer, a plastering layer, a reinforcement clamping groove and a grid cloth layer. The facing layer is compounded on the heat preservation layer through the plastering layer, the reinforcement clamping groove is formed in the plastering layer, and the grid cloth layer covers the upper portion of the reinforcement clamping groove. The A-level flame-retardance heat-preservation decoration integration plate has the advantages that the plate is compounded by multiple layers of A-level flame-retardance structure layers, composite flame-retardance fire-resistance adhesive cement five surfaces of a reinforcement belt mesh embedded part wrap the surface of the heat-preservation plate, prefabrication forming is conducted in a factory, the unit mass is low, the anchoring node is large, the structure is simple, and the demand of the A-level flame retardance is met; through five-surface sealing wrapping of the heat-preservation plate, the flame retardance of the heat-preservation plate is improved, the fireresistance of the integration plate is improved through multiple fireproof structures, and meanwhile the dangers of deformation and warping of a calcium silicate plate or a cement fiber plate and falling-off of the calcium silicate plate or the cement fiber plate during fire disasters are also avoided; through application of a belt-net-type built-in clamping groove, the anchoring connection forceof the integration plate and the wall is larger, and the safety and wind pressure resistance of a system are improved.

The invention relates to the technical field of medical instruments, and provides a graft for repairing or replacing a native valve of the heart. The graft can comprise a first covered stent and a second covered stent, wherein the first covered stent has a first internal passage in an expanded state; an artificial leaflet for replacing a native leaflet is fixedly connected to the interior of the first internal passage; the second covered stent has a second internal passage in an expanded state; the first covered stent is located in the second internal passage and fixedly connected with the second covered stent; the second covered stent is suitable for being anchored to a valve ring and a subvalvular structure; and in the expanded state, the atrial side of the second covered stent has a radially extending flange that is adapted to be located on the atrial side of the valve ring, and the atrial-side end aperture of the second covered stent is greater than the ventricular-side end aperture of the second covered stent. The graft is of a double-layer stent structure, so that the anchoring force of the graft can be increased, the stability is improved, and perivalvular leakage and left ventricular outflow tract obstruction can be reduced.