9810results about How to "Improve structural stability" patented technology

The invention provides a sodium ferric pyrophosphate positive electrode material cooperatively doped with anions and cations, a preparation method of the sodium ferric pyrophosphate positive electrode material and a sodium ion battery, and relates to the field of sodium ion batteries. The anion and cation synergistically doped ferric sodium phosphate pyrophosphate positive electrode material comprises an inner core and a coating layer covering the outer surface of the inner core, the inner core comprises ferric sodium phosphate pyrophosphate, the coating layer comprises carbon, the chemical formula of the ferric sodium phosphate pyrophosphate is Na4-2yFe2.91-xQx (PO4) 2-yP2O7Fy, x is more than 0 and less than or equal to 0.3, and y is more than or equal to 0.03 and less than or equal to 0.08; q comprises at least one of Sn, Ni, Cu, Mg and Mn. The introduced Q positive ions and F negative ions can keep the crystal structure of the body material stable, and the positive ions and the negative ions have a synergistic effect, so that the band gap of the positive electrode material is reduced, the state density near the Fermi level of the positive electrode material is increased, the conductivity of the positive electrode material is enhanced, the specific capacity of the positive electrode material is improved, and the rate and the cycle performance are promoted.

The invention relates to a porous structure manufactured through laser powder bed melting additive manufacturing, in particular to a gradient porous structure with excellent mechanical property and functionality and an LPBF self-adaptive input manufacturing method of the gradient porous structure. According to the method, basic geometric parameters and gradient characteristics of the gradient porous structure are defined by utilizing Grasshopper parameterization design software. A gradient porous structure with excellent mechanical properties and functionality is generated through a grasshopper plug-in of software, and smooth transition from a solid state to a porous state is achieved. An LPBF technology is adopted and combined with an angle partitioning strategy, the gradient porous structure is melted layer by layer, the gradient porous structure is partitioned according to the strut suspension angle on the basis of optimizing process parameters, the optimized process parameters are applied to a model of the partitioned region, and the gradient porous structure is obtained. Scanning of each layer of the overhanging supporting columns at different angles is in appropriate laser parameter input, and the problems of deformation and high porosity caused by heat accumulation in the LPBF process are effectively solved.

The embodiment of the invention relates to a lithium cobalt oxide positive electrode material with a composite phase as well as a preparation method and application of the lithium cobalt oxide positive electrode material. The chemical general formula of the lithium cobalt oxide positive electrode material with the composite phase is AXCo (1-y) M (1y) O2, wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 0.03, A is Li or Li and Na, and M1 is one or more of A1, Zr, Ni, Mn, Y, Nb, La, Fe, Cu, Cr, Ti, W, Mg, Mo or Yb; the composite phase of the lithium cobalt oxide positive electrode material comprises an O2 phase, a T2 phase and an O3 phase; wherein the sum of the molar ratios of the O2 phase and the T2 phase in the composite phase is greater than or equal to 90%, and the molar ratio of the O3 phase is less than or equal to 10%. By regulating and controlling the composite phase proportion of the lithium cobalt oxide positive electrode material, the rate capability, the structural stability under high voltage, the stability of a thermodynamic structure, the specific capacity, a discharge platform and other characteristics of the positive electrode material can be effectively improved, so that the lithium cobalt oxide positive electrode material with high energy density and high stability is realized.

The lithium nickel manganese oxide positive electrode material, the preparation method thereof and the electrochemical device are characterized in that the lithium nickel manganese oxide positive electrode material provided by the embodiment of the invention comprises a base material and a coating layer located on the surface of the base material, the general formula of the base material is Li (LiaNixMnyMbO4), the element M comprises at least one of Ti, Zr, Al, Nb and Mo, and a is more than or equal to 0.02 and less than or equal to 0.06; 0.45 < = x < = 0.55, 1.4 < = y < = 1.6; 0.05 < = b < = 0.55; a + x + y + b = 2, and the coating layer contains phosphate. According to the lithium nickel manganese oxide positive electrode material, through doping and coating technologies, under the condition that the capacity is not sacrificed, the gas production phenomenon is effectively reduced, the cycling stability of the lithium nickel manganese oxide positive electrode material is improved, and the service life of an electrochemical device applying the lithium nickel manganese oxide positive electrode material is prolonged.

The invention belongs to the technical field of polymer plastic materials, and particularly relates to a high-temperature-resistant anti-corrosion polytetrafluoroethylene material and a preparation method thereof. The polytetrafluoroethylene is prepared from the following raw materials in parts by weight: 50 to 60 parts of polytetrafluoroethylene, 5 to 10 parts of fluorinated modified graphene oxide, 3 to 5 parts of aluminum powder, 5 to 8 parts of modified silicon carbide fiber, 3 to 5 parts of silane modified nano silicon dioxide, 2 to 3 parts of polyphenylene sulfide, 2 to 3 parts of polyimide, 0.5 to 0.8 part of dispersing agent and 0.5 to 1 part of antioxidant. The heat conduction performance and the interface bonding force are improved through the fluorinated modified graphene oxide, the impact resistance and the wear resistance are enhanced through the silicon carbide fibers, and the corrosion resistance and the wear resistance are improved through the aluminum powder; silane modified silicon dioxide enhances the mechanical property of the composite material by improving the dispersity of the filler, and PPS and PI interact with the surface of the filler through polar groups in molecular chains, so that the interface strength is improved, and the toughness and the thermal stability are improved.

The invention relates to the technical field of data analysis, in particular to a wind tunnel test analysis method and system for a large-span warehouse structure. The method comprises the following steps: executing a wind tunnel simulation test operation, and collecting wind tunnel test data of the wind tunnel simulation test operation; performing wind pressure quantitative distribution simulation analysis of multi-scale wind direction angles based on wind tunnel test data to generate multi-scale wind pressure quantitative distribution data; designing a wind tunnel test large-span warehouse model according to the wind tunnel simulation test operation; based on the multi-scale wind pressure quantitative distribution data, carrying out wind load analysis on each node of the warehouse on the wind tunnel test large-span warehouse model to generate warehouse wind load data; based on the warehouse wind load data, large-span warehouse structure design parameter analysis is carried out, and large-span warehouse structure design parameters are generated; and transmitting the large-span warehouse structure design parameters to a terminal to execute large-span warehouse structure design parameter feedback operation. According to the method, optimization design of large-span warehouse structure parameters is realized through wind tunnel simulation test analysis.

The invention relates to the technical field of carbon fiber reinforced ceramic matrix composites, in particular to a sintering process of a surface-modified short carbon fiber reinforced ceramic matrix composite, which comprises the following steps: surface modification treatment of short carbon fibers, preparation of a ceramic matrix material, mixing of the short carbon fibers and ceramic powder, compression molding and sintering. In the invention, the process is not only suitable for various ceramic matrixes such as aluminum oxide, silicon carbide, silicon nitride, zirconium oxide and the like, but also can flexibly adjust process parameters such as oxidizing agent types, coupling agent treatment time, ceramic powder particle size, forming pressure, sintering temperature and the like, so that customized preparation with different application requirements is realized; the prepared composite material has extremely high toughness, wear resistance and high-temperature resistance, and shows a wide application prospect.

The invention discloses a preparation method of PEDOT: PSS (poly (3, 4-ethylenedioxythiophene): poly (styrenesulfonate))-based composite fiber with silver nanoparticles loaded on the surface. The method comprises the following steps: uniformly mixing a silver nanowire solution with a PEDOT: PSS solution, or uniformly mixing the silver nanowire solution, the PEDOT: PSS solution and a polymer solution to obtain a spinning solution; extruding the spinning solution into a coagulating bath through a wet spinning process and soaking to obtain nascent composite fibers; and drying the nascent composite fiber to obtain the PEDOT: PSS-based composite fiber of which the surface is loaded with silver nanoparticles and the interior contains silver nanowires. The interior and surface structures of the PEDOT: PSS fiber are simultaneously modified, the interior of the fiber contains a silver nanowire structure, and the surface of the fiber has a silver nanoparticle structure. The composite fiber has the characteristics of ultra-sensitive SERS sensing capability, high conductivity, electric heating, molten drop resistance and antibacterial property.

The invention relates to the technical field of batteries, in particular to a negative active material, a negative plate comprising the negative active material and a battery. The negative electrode active material comprises silicon-carbon composite particles, wherein the silicon-carbon composite particles comprise a porous carbon material and silicon; according to an XRD diffraction pattern of the negative electrode active material, a first diffraction peak exists when 2 theta is 20-30 degrees, and a second diffraction peak exists when 2 theta is 40-50 degrees; the half-peak width of the first diffraction peak is 1-5 degrees, and the half-peak width of the second diffraction peak is 3-10 degrees; the intensity I1 of the first diffraction peak and the intensity I2 of the second diffraction peak meet the condition that I1 / I2 is greater than or equal to 3. The porous carbon material in the negative electrode active material disclosed by the invention has relatively high strength and structural stability, so that the volume expansion of silicon can be effectively improved and the structural stability of the negative electrode active material can be improved while relatively high gram volume of the negative electrode active material is ensured. Comprising the negative electrode active material has relatively high first coulombic efficiency and cycling stability and relatively low cycling expansion rate.

The invention discloses a preparation method of a chitosan-sodium alginate-diatomite composite adsorbent. The preparation method comprises the following steps: (1) carrying out calcination pretreatment on diatomite; (2) dissolving sodium alginate powder in water; (3) adding the calcined diatomite into a sodium alginate solution to prepare a mixed solution a; (4) adding CaCl2 into an acetic acid solution for dissolving; (5) adding chitosan powder into a CaCl2 solution, and uniformly stirring to obtain a mixed solution b; (6) dropwise adding the mixed solution a into the mixed solution b for crosslinking to prepare SA / DM / CS composite gel balls; and (7) washing the gel balls with water for several times, repeatedly freezing and thawing for several times, and drying to obtain the composite adsorbent. The composite adsorbent is prepared by dropwise adding the sodium alginate solution containing the calcined diatomite into the mixed solution of the chitosan and the CaCl2, so that the problem of low mechanical strength of single sodium alginate hydrogel is solved, and the recycling stability of the hydrogel microsphere adsorbent is improved.

The invention discloses a method for rapidly improving a plough layer soil structure of saline-alkali land, which relates to the technical field of agriculture and comprises the following steps: arranging a drainage foundation of a water-permeable concealed conduit, sampling and measuring soil above the water-permeable concealed conduit, including soil bulk density, water content, pH, EC value, SOC and TN content, calculating SOC reserve, determining the proportion of an improver according to a detection result, and determining the soil structure of a plough layer of the saline-alkali land according to the proportion. Performing deep ploughing and rotary tillage treatment, and uniformly applying a modifier; the method comprises the following steps: carrying out rapid fertilization treatment, applying gypsum, biochar, a high-carbon-based organic fertilizer and fulvic acid, carrying out drip irrigation or flood irrigation, planting green manure crops, covering plant straws, turning and pressing into soil, and integrally carrying out hidden pipe salt elimination and deep ploughing physical improvement, gypsum, biochar and high-carbon-based organic fertilizer chemical improvement, straw returning and green manure matched biological improvement. According to the method, through comprehensive measures, the soil structure is rapidly and effectively improved, fertility is improved, salinity is prevented from rising, healthy growth of crops is promoted, and sustainable utilization of the saline-alkali soil is achieved.

The invention relates to the field of flange plate welding, in particular to an automatic flange plate welding device which comprises a fixing table, a three-jaw chuck used for clamping a flange plate is arranged at the upper end of the fixing table, and a fixing mechanism used for fixing the flange plate and a pipeline and a circumferential welding mechanism used for welding the pipeline to the flange plate are arranged above the fixing table. In the downward moving process of the fixing mechanism, the flange plate which is clamped and fixed can be limited in the circumferential direction, the upper end of a pipeline can be pressed, meanwhile, the pipeline can be clamped through the inner clamping assembly, the effect that one machine has multiple functions is achieved, it is ensured that the flange plate and the pipeline reach the optimal alignment state before welding, and the welding efficiency is improved. And meanwhile, the overall structural stability in the welding process can be further improved, the welding quality is improved, and the overall working efficiency is improved.

The invention relates to the technical field of lithium ion batteries, and provides a lithium cobalt oxide composite material which comprises a core body and a coating layer coating the core body, the core body comprises O2-phase lithium cobalt oxide, and the O2-phase lithium cobalt oxide is doped with an element M; the coating layer comprises an oxide containing an N element; the M element comprises at least one of Al, Mg, W, Ti, La, Zr, Ni, Mn and Y; n comprises at least one of Al, Mg, Y, W, Nb, La, Zr, Ti and P. The lithium cobalt oxide composite material provided by the invention is used as a positive electrode material of a lithium ion battery, and the cycling stability of the lithium ion battery under high potential is improved.

The invention belongs to the field of sodium ion batteries, and particularly discloses a positive electrode material and a preparation method and application thereof. The positive electrode material is carbon nitride coated fluorine-doped pyrophosphate sodium manganese iron phosphate, the chemical formula of the positive electrode material is NaaFe3-bMnb (PO4-x) 2F4xP2O7 / C3N4, a is larger than or equal to 3.95 and smaller than or equal to 4.1, b is larger than or equal to 0.3 and smaller than or equal to 2.4, and x is larger than or equal to 0.005 and smaller than or equal to 0.05. The sodium ferromanganese pyrophosphate is subjected to fluorine doping and carbon nitride coating, so that the electronic conductivity and the structural stability of the sodium ferromanganese pyrophosphate can be improved, the capacity of the sodium ferromanganese pyrophosphate can be well exerted, and the capacity and the voltage platform of the sodium-ion battery are improved.

The flexible photovoltaic support wind-resistant system comprises a cable structure and a wind-resistant assembly, the cable structure comprises a main cable assembly, a stable cable assembly and a wind-resistant cable, the main cable assembly comprises a first main cable and a second main cable which are arranged in parallel, and the stable cable assembly comprises a first stable cable and a second stable cable. The extension directions of the first stabilizing cable, the second stabilizing cable and the wind-resistant cable are the same as the extension direction of the first main cable; the wind-resistant assembly comprises a plurality of wind-resistant frames arranged at intervals, the wind-resistant frames are arranged between the main cable assembly and the stable cable assembly, each wind-resistant frame at least comprises a plane frame, and the wind-resistant cables are connected with the wind-resistant frames. According to the flexible photovoltaic support wind-resistant system disclosed by the invention, the stable cable assembly is connected with the main cable assembly through the wind-resistant frame to form a four-cable space cage type structure, and the wind-resistant cable is connected with the wind-resistant frame, so that the structural stability can be improved, and the hidden crack risk of the photovoltaic assembly is reduced. The invention further discloses a flexible photovoltaic support.

The invention belongs to the technical field of lithium ion battery negative electrode materials, and particularly relates to a method for preparing a lithium ion battery negative electrode material from sulfur-doped black phosphorus-carbon. A carbon material and sulfur powder are subjected to ball milling, uniform mixing and vacuum high-temperature calcination to obtain a sulfur-doped carbon material; and uniformly mixing the sulfur-doped carbon material with black phosphorus, and performing high-energy ball milling in an inert atmosphere to obtain the sulfur-doped black phosphorus-carbon composite negative electrode material. According to the preparation method provided by the invention, the black phosphorus, the carbon material and the sulfur are well combined, so that the high capacity of the material is ensured, the structural stability of the composite material can be improved, the polarization of the material is reduced, and the cycling stability and the rate capability of the battery are improved.

The invention discloses a sodium ion battery positive electrode material, a preparation method and a battery. The general formula of a sodium transition metal oxide of the positive electrode material is Na < x > Fe Mn M < c > Nd < LeP < f > O < 2 >, 0.7 < = x < = 0.9, 0.4 > = a > = 0.1, 0.8 > = b > = 0.4, 0.1 > = c > 0, 0.1 > = d > 0, 0.1 > = e > 0, 0.1 > = f > 0, a + b + c + d + e + f = 1, M, N, L and P are four different elements in Li, K, Mg, Ni, Zn, Ca, Cu, Al, B, La, Zr and Ti, and the four selected elements are + 1 valence, + 2 valence, + 3 valence and + 4 valence respectively. In this way, high charging capacity can be provided, and structure expansion and contraction can be suppressed; more active sites are achieved, and ultrahigh discharge capacity and ultrahigh cycling stability are achieved; the structure stability is extremely high, and the sodium ion battery has relatively high specific capacity and relatively long circulation.

The invention belongs to the technical field of bioengineering, and particularly relates to recombinant III-type humanized collagen as well as a coding gene and application thereof. According to the invention, a novel III-type humanized collagen sequence is designed by adopting an advanced AI technology and molecular dynamics simulation, so that the recombinant III-type humanized collagen product is ensured to have high stability and degradation resistance. According to the invention, the screened new III-type humanized collagen sequence is transferred to the pichia pastoris strain for recombinant expression, and the prepared recombinant III-type humanized collagen has the advantages of strong stability, high expression quantity and good hydrophilicity, and meanwhile, the recombinant III-type humanized collagen also has obvious effects of promoting cell proliferation and cell adhesion.

The utility model provides a fluid supply cup which comprises a rigid outer cup and a cup cover which are matched with each other, a plurality of locking slots are formed in the inner circumference of a cup opening of the rigid outer cup, a plurality of clamping elements are correspondingly arranged on the outer edge of the cup cover, and the clamping elements can be guided into the corresponding locking slots to enable the rigid outer cup to be connected with the cup cover. An anti-falling structure is arranged between the clamping element and the corresponding locking groove gap, the clamping element is screwed into the locking groove gap, the clamping element is gradually transited to the locking matching area from the clearance fit area, and the damping force of the anti-falling structure is matched in the clearance fit area. Limiting matching and locking matching of the clamping element and the locking groove gap are separately arranged, the sequential and ordered matching mode is achieved, when the clamping element is screwed out of the locking groove gap, screwing force overcomes wedge-shaped locking force of a thread structure firstly and then overcomes stopping force of an anti-falling structure, and therefore the problem that disassembly and assembly are difficult due to the fact that the clamping element and the locking groove gap face two kinds of composite resistance at the same time can be avoided; and the problem that the outer cup is easily separated from the cup cover can be avoided.

The invention provides a high-barrier fresh-keeping low-temperature heat-sealing composite film and a manufacturing process and application thereof, the composite film sequentially comprises a heat-sealing layer, a barrier layer, a reinforcing layer and a surface treatment layer from the inner layer to the outer layer, and the layers are bonded through bonding layers. The heat-sealing layer is prepared from modified polyethylene, polypropylene and a heat-sealing auxiliary agent, and the barrier layer is made of a composite material of nano aluminum oxide, polyvinylidene fluoride and an ethylene-vinyl alcohol copolymer. The enhancement layer is a polyester film, and the surface treatment layer is subjected to corona treatment. The composite film is prepared through a specific manufacturing process, and the specific manufacturing process comprises the steps of preparation of the heat sealing layer and the blocking layer, compounding, curing treatment, surface treatment and the like. The composite film disclosed by the invention has excellent barrier property and low-temperature heat-sealing capability, is suitable for vacuum packaging or modified atmosphere packaging of foods, and effectively prolongs the fresh-keeping period and the shelf life of the foods.

The invention relates to a gob-side entry retaining grouting reinforcement technology in the field of mining engineering, provides a method for grouting reinforcement of a reuse roof of a gob-side entry retaining of a coal mine and accurate control of the grouting amount, and aims to realize real-time monitoring and control of the grouting amount in the grouting process. According to the method, pressure monitoring, flow velocity monitoring, low-frequency electromagnetic wave detection, ultrasonic detection and on-site drilling slurry discharge monitoring are combined, the grouting process is detected in real time through multiple monitoring means, and it is ensured that cement slurry fills cracks and does not flow into a goaf. And meanwhile, cement paste with different particle sizes is adopted for grouting step by step according to the size of the crack, and paste leakage is avoided while the filling effect is guaranteed. The method is suitable for grouting operation under complex geological conditions, has the characteristics of high efficiency and accuracy, and remarkably improves the stability and safety in the use process of a roadway.

The invention relates to the technical field of sodium ion battery research and development, and particularly discloses a strong-oxidizing acidified asphalt-based hard carbon negative electrode material and a preparation method and application thereof, concentrated nitric acid or concentrated sulfuric acid is introduced into asphalt as a cross-linking agent, so that the cross-linking reaction among molecules can be promoted under a low-temperature condition, and the structural stability of the material is greatly improved. Compared with a traditional method, the method has the advantages that the technological process is simplified, only one-step pretreatment is needed before carbonization, and energy consumption and pollution caused by high temperature can be avoided. According to the liquid phase cross-linking strategy, through reconstruction of chemical bonds, the low-softening-point asphalt can form a more compact carbon precursor network structure at low temperature, and formation of a high-performance hard carbon material in the subsequent carbonization process is facilitated.

The invention relates to the technical field of frame type hydraulic machines, and discloses a machining device and process of a stand column for a frame type hydraulic machine. The device comprises a welding center, and the welding center is composed of a positioning mechanism, a welding mechanism, a reversing assembly, a driving assembly, a preheating assembly, a grinding mechanism and a plurality of auxiliary supporting mechanisms; the welding center is further provided with an outer circular pipe and an inner circular pipe, the positioning mechanism is installed in the inner circular pipe, the driving assembly is integrally assembled on the positioning mechanism, directional conveying of the steel component during welding is achieved, meanwhile, the steel component is pressed, the welding stress is reduced, and the reversing assembly is installed in the outer circular pipe and used for supporting and driving the inner circular pipe to rotate in the axial direction. According to the technical scheme, the assembly type inner framework can play a supporting role from the interior of the square tube during welding, the assembly type inner framework and the square tube form a whole after welding, the structural stability of the stand column during use is effectively improved, and meanwhile steel members can be pressed from the corners of the stand column to reduce welding stress.

The embodiment of the invention relates to the photovoltaic field, and provides a solar cell and a preparation method thereof, and a photovoltaic module, the solar cell comprises a substrate having a first surface and a second surface opposite to each other, and the first surface comprises first regions and second regions which are alternately arranged; the first passivation structure is located on the first region and comprises a first passivation layer and a first semiconductor doping layer which are stacked; the second passivation structure is at least located on the second region and comprises a second passivation layer and a second semiconductor doping layer which are stacked; the first surface further comprises a junction region, the junction region comprises a part of at least one of the first region and the second region, the side wall of the first semiconductor doping layer and the side wall of the second semiconductor doping layer are in contact on the junction region, and the junction region is provided with a crystallization doping part; the crystallized doped portion is a portion of at least one of the first semiconductor doped layer and the second semiconductor doped layer. The embodiment of the invention is at least beneficial to improving the hot spot effect of the battery assembly formed based on the solar battery.

The invention provides a modified lithium iron manganese phosphate positive electrode material and a preparation method thereof, a positive plate and a lithium ion battery. The modified lithium manganese iron phosphate positive electrode material comprises transition metal element-doped lithium manganese iron phosphate and a silicon hydroxyl-containing carbon coating layer, wherein the surface of the transition metal element-doped lithium manganese iron phosphate is coated with the silicon hydroxyl-containing carbon coating layer. And the transition metal element replaces the position of an iron element in the lithium manganese iron phosphate, so that the ion diffusion coefficient of the lithium manganese iron phosphate and the compaction density of the modified lithium manganese iron phosphate positive electrode material can be improved. The existence of the silicon hydroxyl-containing carbon coating layer is beneficial for improving the electronic conductivity and the structural stability of the lithium manganese iron phosphate positive electrode material, so that the manganese dissolution rate of the lithium manganese iron phosphate positive electrode material in the high-temperature cycle process of the battery is reduced. Therefore, the modified lithium manganese iron phosphate positive electrode material disclosed by the invention has relatively high ion diffusion coefficient, electronic conductivity, compaction density, rate capability, energy density and cycling stability.

The invention belongs to the technical field of battery positive electrode preparation, and particularly relates to a mixed coating coated nickel-rich layered oxide positive electrode and application thereof. The mixed coating coated nickel-rich layered oxide positive electrode is an NCM system positive electrode material, and the proportion of a Ni material in an NCM ternary system is greater than or equal to 92 wt%; the ratio content of Ni of the nickel-rich layered oxide positive electrode coated with the mixed coating in three elements of Ni, Co and Mn is greater than or equal to 92 mol%; and the nickel-rich layered oxide positive electrode coated with the mixed coating is coated with Li3PO4 and / or Li3BO3 and / or LiNbO3. The positive electrode material provided by the invention can effectively reduce the space charge layer effect and interface side reaction between the positive electrode and the electrolyte, the lithium ion migration efficiency is high, and the cycle performance of the assembled battery is good.

The invention belongs to the technical field of medical materials, and particularly relates to a seawater self-adhesive wound dressing capable of rapidly stopping bleeding and a preparation method of the seawater self-adhesive wound dressing. The electrospun fiber wound dressing provided by the invention contains an efficient hemostatic, and can quickly promote blood coagulation, shorten the hemostasis time and provide timely and effective first-aid measures for patients. By means of the multi-layer structural design, especially the self-adhesive waterproof layer, seawater permeation can be effectively prevented, wounds are protected against seawater erosion, and the infection risk is reduced. The composite breathable film with the gradient aperture design is adopted, it can be guaranteed that water vapor in the wound area is discharged smoothly, invasion of outside moisture and bacteria can be blocked, and the wound is kept dry and clean. The electrospun fiber wound dressing provided by the invention has the advantages of rapid hemostasis, seawater erosion prevention, excellent self-adhesion, good air permeability, structural stability and the like, and is a wound dressing suitable for wound treatment in marine emergency rescue and daily marine activities.

The invention discloses a method for preparing a composite iron-based polyanion positive electrode material. The structural formula of the positive electrode material is represented as Na4Fe3 (PO4) 2 (P2O7) (at) Camp, mXenes are sodium ferric pyrophosphate compositely coated by an MXenes material and a carbonaceous precursor, and the preparation method comprises the following steps: weighing a sodium source, a ferrous source, a phosphorus source and a carbon source according to a stoichiometric ratio, uniformly mixing, grinding, spray-drying and sintering at high temperature to obtain the composite iron-based polyanion positive electrode material, and the carbon source comprises iron-nickel doped polyethylene glycol. The composite iron-based polyanion positive electrode material provided by the invention is remarkably improved in the aspects of energy density, rate capability and cycle life, and the preparation process is simple to operate, reliable in flow, quick in preparation process and easy for industrial production, so that an ideal scheme is provided for commercialized sodium ion battery positive electrode materials.

The invention discloses a quasi-zero stiffness metamaterial vibration reduction mounting structure of an underwater vehicle hydrophone, which belongs to the technical field of underwater vehicles, and comprises an oil seal end cover mounted at the front end of a front fairing of an underwater vehicle, a mounting rack fixed at the front end part of the oil seal end cover, and two quasi-zero stiffness vibration reduction components arranged in front of and behind the mounting rack, the outer side parts of the quasi-zero-stiffness vibration reduction components are connected with the mounting frame, concave parts for clamping the end parts of the hydrophone are formed in the middle parts of the quasi-zero-stiffness vibration reduction components, and a mounting space for arranging the hydrophone is formed between the two quasi-zero-stiffness vibration reduction components; and the two ends of the hydrophone are respectively clamped and clamped in the concave parts of the two quasi-zero stiffness damping components. According to the quasi-zero-stiffness metamaterial damping device, through conformal design, vibration attenuation, structure optimization and energy-saving effects, an efficient, stable and low-noise hydrophone installation solution is provided for an autonomous underwater vehicle, and the performance of the quasi-zero-stiffness metamaterial damping device in underwater detection and signal acquisition is remarkably improved.

The invention provides a nickel-metal hydride battery positive electrode material and a preparation method thereof, a nickel-metal hydride battery and electric equipment, the nickel-metal hydride battery positive electrode material is nickel-containing hydroxide doped with cobalt element and zinc element, the nickel-metal hydride battery positive electrode material comprises secondary particles composed of a plurality of primary particles, and the section porosity of the secondary particles is less than or equal to 3.0%. The nickel-metal hydride battery positive electrode material provided by the embodiment of the invention is doped with the cobalt element and the zinc element, attenuation of the capacity and the service life of the positive electrode material at high temperature can be slowed down through the doped elements, and the secondary particles are integrally of a compact structure, have few internal pores and are not easy to crack when bearing stress, so that the nickel-metal hydride battery positive electrode material is better in structural stability, and the service life is prolonged. And the cycle performance and the capacity retention ratio can be considered.