665results about How to "Reduce degradation" patented technology

The invention relates to the technical field of coatings, and provides an antifouling coating as well as a preparation method and application thereof. The antifouling paint comprises a component A and a component B, wherein the component A comprises fluorosilicone modified acrylic resin, fluorinated paraffin, modified nano attapulgite, a wetting agent, a defoaming agent and a dispersing agent; a modifying agent of the modified nano attapulgite is 2-imidazole-1-ethylamine and 2-(3, 4-cyclohexyl oxide) ethyl triethoxy silane, and a modifying agent of the modified nano attapulgite is 2-imidazole-1-ethylamine and 2-(3, 4-cyclohexyl oxide) ethyl triethoxy silane; and the component B comprises a curing agent and a diluent. The nano attapulgite is modified, so that the dispersity of the nano attapulgite in the coating and the compatibility of the nano attapulgite with resin are improved, the nano attapulgite can be subjected to cross-linking reaction with other network structures to form a more compact cross-linked network, and the mechanical strength and the wear resistance of the coating are further improved.

The invention discloses a lithium iron phosphate carbon nanotube composite material and a preparation method thereof, and belongs to the technical field of battery materials. The polydopamine is used as a carbon source to coat the lithium iron phosphate, so that the direct contact between the lithium iron phosphate and the electrolyte is avoided; meanwhile, the compatibility of the carbon nanotube composite material and the lithium iron phosphate is enhanced due to the strong adhesion, so that the carbon nanotube composite material is favorably adsorbed on the lithium iron phosphate to be sintered; a carbon coating layer formed by polydopamine and the carbon nanotubes are beneficial to permeation of an electrolyte and exposure of surface active sites, and metal ions are introduced into the carbon nanotubes of the carbon nanotube composite material, so that the electrochemical performance of the material is improved, and meanwhile, the carbon nanotubes are supported; the condition that the cyclicity of the material is reduced due to collapse of the carbon nano tube in the reaction process is prevented; cobalt is introduced outside the carbon nano tube, so that the energy density of the battery can be improved, the structures of the carbon nano tube and the positive electrode material can be stabilized, and the degradation of the material is reduced.

The preparation method comprises the following steps: firstly, analyzing the amino acid sequence of an alpha 1 chain of the human XVII type collagen, and selecting partial amino acid fragments which are not easily degraded by endogenous or exogenous protease in non-transmembrane regions of different functional domains of the protein; the recombinant collagen gene fragment (Col17a) n is obtained by repeatedly splicing the recombinant collagen gene fragment (Col17a) n; then introducing homologous promoters from different methylotrophic yeasts to the 5'end of a recombinant collagen gene segment, optimally synthesizing selected (Col17a) n and promoter segments, obtaining a connecting segment by utilizing PCR cloning, connecting the collagen segment (Col17a) n, the promoter segments and a pPIC9K carrier skeleton segment by virtue of a Gibson Assessment seamless connection technology, and obtaining the recombinant collagen gene. And constructing to obtain the pichia pastoris expression plasmid pPIC9K-(Col17a) n of the recombinant human source XVII type collagen.

The invention discloses a halogen-free flame-retardant reinforced PBT (polybutylene terephthalate) composition as well as a preparation method and application thereof, and relates to the technical field of high polymer materials. The halogen-free flame-retardant reinforced PBT composition comprises polybutylene terephthalate, a halogen-free flame retardant, a melamine flame-retardant synergist, glass fibers, a phenol amide metal deactivator, a free radical trapping agent and a hydroperoxide trapping agent. According to the halogen-free flame-retardant reinforced PBT composition disclosed by the invention, under the combined action of all the components, the effects of improving the flame retardance, the ignition temperature of a glowing filament and the heat-resistant stability can be achieved, and the halogen-free flame-retardant reinforced PBT composition has relatively high mechanical properties. The flame retardant property of the halogen-free flame-retardant reinforced PBT composition reaches V-0 or above, the tensile strength is 95 Mpa or above, the glowing filament ignition temperature is 800 DEG C or above, and the thermal weight loss T1% temperature is 335 DEG C or above.

The invention discloses a preparation method of a flame-retardant anti-aging polyolefin plastic, and belongs to the technical field of polyolefin material processing.The preparation method comprises the steps that a modified anti-aging agent is mixed with a DOPO-based flame retardant modified by introducing isocyanate and epoxy groups, the mixture is added into a polyolefin material, during combustion, carbon formation is promoted by the phosphorus element, and the flame-retardant anti-aging polyolefin plastic is obtained. The flame retardant and nitrogen element synergistically play a flame-retardant role, meanwhile, epoxy groups in the flame retardant and carboxyl of polypropylene are subjected to a ring-opening reaction, the crosslinking degree of the material is enhanced, the modified anti-aging agent can effectively capture free radicals and inhibit oxidative degradation, and the mechanical strength and flame-retardant effect of the material are improved. According to the modification method, the anti-aging, high-temperature-resistant and flame-retardant properties of the polyolefin plastic are remarkably improved, the stability of the polyolefin plastic in high-temperature and severe environments is enhanced, the service life is prolonged, and the mechanical property and the thermal stability of the polyolefin plastic are improved.

The invention relates to the technical field of material processing, and discloses a silicon-containing composition for processing a chlorine-containing polyolefin material and a preparation method, which are used for solving the problems of processing and extrusion of the chlorine-containing polyolefin composite material. The invention relates to a silicon-containing composition for processing a chlorine-containing polyolefin material. The silicon-containing composition comprises 5-95 parts of modified polysiloxane, 5-95 parts of hydrocarbon wax, 5-95 parts of fatty acid amide, 5-95 parts of metallic soap and 1-5 parts of other auxiliaries. The silicon-containing composition for processing the chlorine-containing polyolefin material is applied to processing and extrusion of the chlorine-containing polyolefin composite material, modified polysiloxane not only contains a plastic-loving part but also contains a filler-loving part, and meanwhile, the whole molecular structure takes organic silicon as a main chain, so that the special performance of the organic silicon is achieved; according to the present invention, the chlorine-containing polyolefin composite material is compounded with other lubricants so as to achieve efficient internal and external lubrication, high cost performance and no precipitation, can effectively delay the decomposition time of the chlorine-containing polyolefin, can weaken the adhesion effect between the chlorine-containing polyolefin and the metal, can substantially prolong the screw cleaning time during the processing of the chlorine-containing polyolefin composite material, and can improve the production efficiency.

According to the anion exchange polymer, the anion exchange membrane, the method and the device provided by the invention, a cationic group with high alkali resistance is introduced into a polyaryl polymer structure, and meanwhile, a cationic side chain is introduced, so that the ionic conductivity and the alkali-resistant stability of the anion exchange polymer are synchronously improved; the anion exchange membrane prepared from the anion exchange polymer has the advantages of excellent ionic conductivity and alkali-resistant stability, can stably operate for a long time in a high pH value environment, and is not easy to degrade or reduce the performance. Therefore, the anion exchange membrane has remarkable advantages in electrochemical processes such as water electrolysis hydrogen production, so that the anion exchange membrane has a wide application prospect in electrochemical devices such as a water electrolysis reactor and the like.

The invention discloses a train communication network intrusion detection method based on a multi-scale residual network, and the method comprises the following steps: building a train communication network topological structure model, and building a traffic model for the mixed transmission of normal traffic and intrusion traffic; collecting a flow data packet in a link as an original data sample in the intrusion detection data set, and performing preprocessing to obtain a data sample containing statistical characteristics; a train communication network intrusion detection MSRNet-GLAM model is constructed, and the performance of the train communication network intrusion detection MSRNet-GLAM model is checked and evaluated, so that the MSRNet-GLAM model can learn key feature information of a data sample in a multi-scale manner; and training and optimizing the MSRNet-GLAM model by using the improved focus loss function, and performing intrusion detection on the traffic data of the train communication network to be detected to obtain a traffic detection result of the train communication network. The method can effectively solve the problems of low security and difficulty in detection of intrusion traffic under the trend of mass data communication of the train communication network, and ensures the security of the train network.

The invention discloses a method for detecting the content of monosaccharide components in bacterial capsular polysaccharide or a conjugate thereof, and belongs to the field of biological product detection. Taking pneumococcus as an example, different hydrolysis methods are adopted for different serotypes of capsular polysaccharides, connected glucosidic bonds are broken through hydrolysis, released monosaccharide components and 1-phenyl-3-methyl-5-pyrazolone are subjected to derivatization under the alkaline condition to generate derivatives with ultraviolet absorption, and then the capsular polysaccharides with different serotypes are obtained. And then detecting the composition and the content of each monosaccharide generated by polysaccharide hydrolysis through liquid chromatography. According to the method, each monosaccharide component can be quickly and effectively hydrolyzed, meanwhile, various polysaccharides with different structural characteristics can be separated and detected by adopting a derivatization method, whether the monosaccharide composition of each serotype polysaccharide accords with a theoretical structure or not can be qualitatively analyzed, and the content of each monosaccharide component can be quantitatively determined to calculate the content of the polysaccharides; and a better technical support is provided for quality control of the antigen component capsular polysaccharide of the bacterial vaccine.

The invention relates to dithiolane modified beta-cyclodextrin, a preparation method thereof and application of the dithiolane modified beta-cyclodextrin as a drug carrier. The method comprises the following steps: carrying out acylation reaction on beta-cyclodextrin and lipoic acid, and modifying different numbers of dithiolane on the beta-cyclodextrin by changing a feeding ratio; the beta-cyclodextrin has a plurality of hydroxyl groups, and the activity of the hydroxyl groups at the C6 position is relatively high. The hydrophobic cavity of the dithiolane-modified beta-cyclodextrin can be loaded with a hydrophobic small-molecule drug, and the hydrophobic small-molecule drug can be loaded into the dithiolane-modified beta-cyclodextrin under the condition of heating reflux to form a nano-drug. The disulfide bond on the surface of the nano-drug and sulfydryl on protein or lipid on the outer side of a cell membrane are subjected to dynamic covalent thiol exchange, so that the nano-drug enters cells through a thiol-mediated cellular uptake way, endosomes and lysosomes can be avoided, the drug is quickly and directly delivered to the cytoplasm, degradation of the drug in the lysosomes is reduced, and the drug delivery efficiency is improved. The utilization rate of small-molecule drugs is improved, side effects are reduced, and better curative effects are achieved.

The invention discloses eye cream containing a composition capable of improving eye skin problems and a preparation method of the eye cream, and belongs to the technical field of cosmetics. The eye cream provided by the invention contains a repairing composition, and the repairing composition is prepared from the following raw materials: an acer rubrum extract, a zingiber zingiberensis extract, a dendrobium officinale extract, a North American arbor pine bark extract and an epilobium fragile extract. The repairing composition provided by the invention has the effects of resisting aging, fading wrinkles and improving the migration rate of skin cells, and the whole repairing composition is mild and non-irritant; when being applied to the eye cream, the repairing composition can effectively resist aging, lighten wrinkles, improve skin elasticity and increase the water content of cuticle. In addition, the composition provided by the invention is natural in component source, simple in preparation method and suitable for actual production.

The invention relates to the technical field of polyester fiber modification, and particularly discloses a large polyester bio-fiber containing a lavender active component and a preparation method of the large polyester bio-fiber containing the lavender active component. Comprising the following raw materials in parts by weight: 100-300 parts of polyester chips, 5-10 parts of lavender active ingredients, 10-20 parts of modified mica sheets, 10-20 parts of a coupling agent and 1-3 parts of a dispersing agent, besides, the lavender leaves are subjected to enzymolysis through the compound enzyme, then the deep-eutectic solvent is adopted for extraction, and the two steps are combined, so that active ingredients in the lavender leaves can be fully extracted. The polyester fiber provided by the invention has excellent aging resistance and antibacterial performance, and has a wide market prospect.

The invention belongs to the technical field of polyurethane elastomers, and particularly relates to a hollow glass bead / TPU composite material for an air bag of a life jacket and a preparation method of the hollow glass bead / TPU composite material. The polyurethane resin is prepared from the following raw materials in percentage by mass: 48%-61% of polyether glycol, 28%-33% of diisocyanate, 5%-9% of a mixed chain extender, 0.2%-0.4% of a hydrolysis-resistant agent, 0.3%-0.5% of an antioxidant, 0.2%-0.4% of a catalyst and 5%-9% of modified hollow glass beads. The TPU material is firm, durable and not prone to damage, the buoyancy of the TPU material is improved through the modified hollow glass beads, and meanwhile the binding force of the hollow glass beads and TPU is increased. The invention also provides a preparation method thereof.

The invention discloses a multi-cable parallel connection anti-bias cable structure, and relates to the technical field of cables, the cable structure comprises a cable body, the cable body is provided with a mounting mechanism, the mounting mechanism comprises a circular ring groove, two circular pipes, a three-way pipe, a sealing plug and a clamping groove, and a rectangular block is fixed in the circular ring groove; according to the invention, the installation mechanism is arranged, so that the multi-cable parallel-connection anti-bias-current cable and the suspension wire can be conveniently installed in an overhead manner in the long-distance overhead laying process, that is, when the multi-cable parallel-connection anti-bias-current cable is subjected to long-distance overhead laying, a constructor can distribute and install the suspension wire and the cable at equal intervals; therefore, the situation that the service life of the cable is affected due to uneven stress of the cable is avoided, the using effect of the multi-cable parallel connection anti-bias-current cable is improved, and meanwhile the using efficiency of the multi-cable parallel connection anti-bias-current cable is improved.

The invention relates to the technical field of chemical additives of building materials, in particular to an anti-corrosion concrete additive and a preparation method thereof. The concrete additive comprises the following components in parts by weight: 40-80 parts of fly ash, 10-20 parts of modified plant fibers, 5-8 parts of a water reducing agent, 3-6 parts of inorganic salt and 10-30 parts of water, and the modified plant fibers are obtained by grafting and modifying semi-carbonized plant fibers and fluorosilane; the water reducing agent is an amphoteric polycarboxylic acid water reducing agent. In the anticorrosive concrete additive provided by the invention, concrete pores are filled with the fly ash, so that the microstructure is improved; the modified plant fiber enhances the mechanical property and crack resistance of the concrete; the amphoteric polycarboxylate superplasticizer not only improves the workability of the concrete, but also forms a protective film on the surface of the steel bar; the inorganic salt further enhances the impermeability of the concrete, and the additive can comprehensively improve the comprehensive performance of the concrete, especially the corrosion resistance and the service life of the concrete in a severe environment through multi-component compounding.

The invention discloses recombinant escherichia coli for producing NMN through fermentation and application of the recombinant escherichia coli, and belongs to the technical field of genetic engineering and biological engineering. According to the invention, nicotinamide phosphoribosyltransferase NAMPT, PRPP synthase BaPRS, transport protein BMpnuC, glucose-6-phosphate 1-dehydrogenase EcZwf, 6-phosphogluconate dehydrogenase EcGnd, fructose-1, 6-diphosphatase II EcGlpX, vitreous hemoglobin enzyme Vhb and NADH transhydrogenase EcSthA are expressed in Escherichia coli, and a pncC gene, a ushA gene, an nadR gene, a purR gene, a pncA gene, an edd gene, an gntR gene, a pfkA gene and a pntAB gene are knocked out, so that the recombinant plasmid is obtained. The accumulation amount of NMN in escherichia coli cells is increased, and fermentation conditions are further optimized, so that the strain can obtain more than 4.9 g / L of NMN at a shake flask level.

The invention relates to the field of genetic engineering, in particular to a genetically engineered bacterium for efficiently synthesizing 5-aminolevulinic acid. According to the invention, a synthetic biological technology and a genetic engineering means are utilized, escherichia coli E.coli BL21 (DE3) is taken as an original strain, a C5 way of the escherichia coli E.coli BL21 (DE3) is modified, and degradation of glutamic acid is reduced by knocking out a gadA gene and replacing a promoter of an argE gene; the synthesis of the 5-aminolevulinic acid is increased by enhancing the expression of gdhA, hemAS and hemL genes, replacing promoters and increasing the carbon flux flowing to the 5-aminolevulinic acid; in addition, by knocking out acetic acid synthesis genes ackA, poxB and pta, the loss of carbon flux flowing to TCA circulation is reduced, so that the purpose of increasing the yield of 5-aminolevulinic acid is achieved.

The invention provides a para-aramid fiber and a preparation method thereof.Under the sealed condition, poly-p-phenylene terephthamide resin with the water content lower than 500 ppm and the viscosity of 6.5 dL / g-7. 5 dL / g and concentrated sulfuric acid solid particles are mixed, defoamed and filtered to obtain a spinning solution, then tows are obtained through a dry jet wet spinning method, and finally multi-stage drying is conducted to obtain the para-aramid fiber. The high-strength and high-modulus para-aramid fiber is obtained. The concentrated sulfuric acid solid particles are used as raw materials, the mixing and permeation effects of concentrated sulfuric acid on resin are enhanced, the slurry sandwich phenomenon is reduced, polymer degradation is relieved, a high-quality spinning solution is provided for preparing the high-strength and high-modulus aramid fiber, and the strength and modulus of the para-aramid fiber, especially the modulus, are greatly improved.

The invention relates to the technical field of isocyanate reaction, and discloses a reaction device for preparing o-tolyl isocyanate and a reaction method thereof.The reaction device comprises a reaction box, a cleaning and stirring mechanism is arranged in the reaction box and used for stirring and cleaning crystals adsorbed on the inner wall, an intermittent conveying mechanism is arranged on one side of the cleaning and stirring mechanism, and the intermittent conveying mechanism is arranged on the other side of the cleaning and stirring mechanism. The phosgene intermittent conveying device is provided with a clean stirring mechanism for intermittently conveying phosgene, the clean stirring mechanism is provided with a pressing discharging mechanism for pushing isocyanate to be rapidly discharged, it is guaranteed that reactants are evenly distributed in the whole reaction mixture through stirring, the local concentration is prevented from being too high or too low, and therefore the overall reaction efficiency and the product quality are improved; according to the reaction device, crystals can be shoveled down from the wall surface during stirring, the service life of the reaction device is prolonged, meanwhile, communication of the exhaust pipe is intermittently cut off, a communication hole in one side of the intermittent rotary table is communicated with the exhaust pipe, and the concentration of reactants in a reaction mixture can be adjusted by intermittently cutting off conveying of phosgene, so that the reaction rate is controlled.

The invention relates to the technical field of bioengineering, in particular to a system for producing valerolactam through whole-cell catalysis and application of the system. The system provided by the invention comprises L-lysine, and also comprises halomonas with the functions of synthesizing 5-aminovaleric acid, inhibiting GabT protein and enhancing beta-alanine coenzyme A transferase. According to the method, L-lysine is taken as a substrate, halomonas is utilized, 5-aminovaleric acid is synthesized firstly, degradation of the 5-aminovaleric acid is reduced by inhibiting the function of GabT protein in the halomonas, the function of beta-alanine coenzyme A transferase is enhanced, the metabolic flux from the 5-aminovaleric acid to the valerolactam is increased, and finally the valerolactam is efficiently produced.

The invention belongs to the field of organic electroluminescent materials, and discloses a blue light host material, a preparation method and an organic electroluminescent device. The structure of the blue light host material is as shown in a chemical formula I: # imgabs0 #. After the blue light host material provided by the invention is applied to the organic electroluminescent device, the driving voltage of the photoelectric device can be reduced, the luminous efficiency of the photoelectric device can be improved, and the service life of the photoelectric device can be prolonged.

The invention discloses a flame-retardant eutectic polymer electrolyte based on in-situ polymerization, a preparation method and a solid-state lithium battery, and belongs to the technical field of lithium battery polymer electrolytes.The preparation method comprises the following steps that in the inert gas atmosphere, an amide hydrogen bond donor and alkali metal salt are evenly mixed, and a mixture is obtained; the eutectic electrolyte is obtained by utilizing the interaction of Li-N and Li-O; adding a functional additive, an ester polymer monomer and an initiator into the eutectic electrolyte, and uniformly mixing to obtain a precursor solution; and injecting the precursor solution into a diaphragm in a lithium ion battery to be assembled, sealing, and performing in-situ free radical polymerization reaction to form the flame-retardant eutectic polymer electrolyte, thereby obtaining the solid-state lithium battery of the flame-retardant eutectic polymer electrolyte based on in-situ polymerization. The eutectic polymer electrolyte disclosed by the invention has a flame-retardant property, the safety of the lithium battery is greatly improved, meanwhile, the eutectic polymer electrolyte has high ionic conductivity, the rate capability of the battery is improved, and stable long circulation of the assembled solid-state lithium battery is realized.

The invention belongs to the field of chemical fibers, and particularly relates to a method for preparing polyester industrial filaments by using recycled polyester chips recycled from bottles and the prepared polyester industrial filaments, regenerated PET chips with the viscosity of 0.65-0.8 dl / g and the filtration value of 0-5 MPa are selected, 1.0-1.3 dl / g regenerated high-viscosity chips are obtained after tackifying, and spinning is carried out on an existing industrial filament production line; the temperature of a screw is controlled to be 280-330 DEG C, and the lengths of a feeding section and a metering section are adjusted, so that the slices are fully melted, meanwhile, it is ensured that a large amount of melt is not degraded due to the fact that the melt contains IPA, and the stability of the outlet pressure of the screw is ensured; a spinning assembly adopts a multi-layer metal filter screen structure of 5-30 [mu] m, so that the problem that the spinning assembly is quickly boosted due to many impurities of regenerated slices is solved; and the stretching and setting conditions are optimized and adjusted, so that the physical property, broken filaments and spinnability can meet the requirements.

The invention belongs to the technical field of biological medicine, and particularly relates to sterile cefepime hydrochloride and a direct preparation method thereof. The method comprises the following steps: firstly, carrying out condensation reaction on a 7-MPCA solution and an AE active ester solution through a solid base catalyst column at the same time; then, carrying out extraction phase separation, two times of pH regulation crystallization, activated carbon decoloration and sodium sulfite reduction on the condensation liquid to obtain a cefepime hydrochloride liquid to be crystallized; and then taking a part of the cefepime hydrochloride to-be-crystallized liquid to prepare a seed crystal mixed liquid, and adding the rest of the cefepime hydrochloride to-be-crystallized liquid and the crystallization solvent into the seed crystal mixed liquid at a specific speed to obtain the sterile cefepime hydrochloride. According to the method disclosed by the invention, the continuous production of the sterile cefepime hydrochloride is realized, the preparation period of the sterile cefepime hydrochloride is greatly shortened, side reactions and product degradation are reduced, the quality and yield of the obtained cefepime hydrochloride product are relatively high and stable, and industrial production is facilitated.

The invention belongs to the technical field of agricultural mechanization and intelligent equipment, and particularly relates to a corn harvester operation soil compaction degree judgment method based on machine tool real-time parameters, in particular to a soil compaction degree judgment method. The invention aims to solve the problem of low soil compaction prediction accuracy caused by the fact that the existing soil compaction prediction method considers soil indexes and machine pressure and does not consider the influence of dynamic indexes which can be autonomously controlled by a driver on soil compaction. The method comprises the steps of 1, collecting a feature data training set; 2, obtaining a standardized feature data training set; 3, obtaining an optimal compaction degree prediction model; 4, constructing an optimal comprehensive compaction degree model; 5, constructing an optimal compaction early warning model; 6, constructing an optimal comprehensive compaction risk early warning model; 7, collecting a to-be-detected feature data set, obtaining an optimal comprehensive compaction degree model of the to-be-detected feature data set, and outputting a comprehensive compaction degree value and a risk early warning level; and 8, pushing on a screen end in real time.

The invention relates to the technical field of capacitor electrode material preparation, in particular to a sulfur-doped nickel-manganese layered double hydroxide electrode material, a preparation method and a capacitor, and the preparation method comprises the following steps: growing sulfur-doped nickel-manganese layered double hydroxide on foamed nickel by using a simple and feasible one-step hydrothermal method; oxygen vacancies are introduced into the electrode material through a safe and harmless chemical reduction method; wherein the layered double hydroxide has a relatively large specific surface area and rich active sites, so that permeation of electrolyte and diffusion of ions are facilitated; through combination of sulfur doping and oxygen vacancy, the electronic structure of the electrode material can be synergistically optimized, and the electrolyte adsorption capacity and the electronic conductivity of the electrode material are enhanced. The problems that in the prior art, due to the fact that transition metal layered double hydroxides are low in electric conductivity and poor in electron transmission efficiency, actual energy density and power density are low, and cycling stability is poor are solved.

The invention relates to the technical field of textile materials, and particularly discloses high-strength screen cloth and a preparation method thereof. The high-strength screen cloth is prepared from the following raw materials: caprolactam, p-phenylenediamine, adipic acid, diphenyldicarboxylic acid, a modified monomer, zinc diethyl hypophosphite, divinyl benzene, modified glass fibers, an antioxidant and a lubricant. The preparation method comprises the following steps: preliminarily polymerizing caprolactam, p-phenylenediamine, adipic acid, biphenyldicarboxylic acid and the modified monomer, then adding the modified glass fiber, zinc diethyl hypophosphite and divinyl benzene for continuous reaction to obtain a polyamide copolymer, and finally performing melt spinning and weaving on the polyamide copolymer, the antioxidant and the lubricant to obtain the required high-strength mesh cloth. The high-strength screen cloth prepared by the invention has excellent mechanical properties and aging resistance, is suitable for being applied to the fields with high-performance requirements, such as constructional engineering materials and special protective equipment, and is high in practicability and wide in application prospect.

The invention discloses a double transition metal / chitosan-based carbon aerogel composite material and a preparation method and application thereof.The method comprises the steps that a nitrogen source and transition metal salt are added into a hydrochloric acid solution of chitosan, stirred, dissolved and evenly dispersed to prepare a mixed solution, the mixed solution is subjected to freeze drying, and the double transition metal / chitosan-based carbon aerogel composite material is obtained. Chitosan aerogel containing transition metal and a nitrogen source is prepared; the transition metal salt is any two of ferric salt, cobalt salt and nickel salt; the chitosan aerogel containing the transition metal and the nitrogen source is placed in a methanol solution of 2-methylimidazole, after vibration treatment and drying, the chitosan aerogel is placed in a nitrogen atmosphere to be subjected to heat treatment, and the double-transition-metal / chitosan-based carbon aerogel composite material is prepared. The preparation method is simple and reasonable in design, the prepared material has good specific surface area and porosity, the formed metal-nitrogen double active center effectively improves the adsorption performance of the material, and the material has good catalytic performance.

The invention discloses a preparation method of a composite spray for improving the hemostatic ability of a wound part, the composite spray comprises a liquid A and a liquid B. The liquid B is a sodium alginate aqueous solution, a preparation method of the solution A comprises the following steps: 1, dissolving a lipopeptide conjugate, cholesterol, distearoyl phosphatidylcholine, distearoyl phosphatidylserine and dimethyl sulfoxide in a chloroform-methanol mixed solution to obtain a mixed system; 2, preparing the mixed system into a precursor solution by utilizing a film hydration method; 3, adding calcium chloride into the precursor solution, and reacting in a dark place to obtain a solution A; a precursor solution is designed according to the function of natural platelets, the function of the precursor solution is equivalent to that of nano platelets, the precursor solution is matched with sodium alginate, adverse effects on a blood coagulation system caused by fibrin degradation, platelet activation capability reduction and the like of a wound part due to blood loss can be relieved in a targeted manner, and the preparation has the advantages of rapid hemostasis, good biological activity, no toxic or side effects and the like. And the wound healing is rapid.

The invention relates to the technical field of medical instruments, in particular to an adjustable bone-to-bone fixing device with a main nail and an implanting mechanism device.The adjustable bone-to-bone fixing device comprises the main nail, a fixing coil, a first auxiliary nail and a second auxiliary nail. Early load-bearing exercise of ankle joints of a patient is facilitated, ankle joint degeneration and traumatic arthritis are reduced, and the risk of fracture of an implant is greatly reduced; compared with elastic fixation, two fixing points are taken on the tibia, one fixing point is taken on the fibula, all the fixing points are connected through sutures, and the length of the sutures is adjustable, so that the tibia can bind the fibula in a surrounding mode through the sutures, compared with a single-strand suture transverse fixation mode, the fixation mode is closer to a native ligament, and fixation is more stable and reliable; and moreover, the micro-motion function between the tibia and the fibula is reserved while the bone removal amount is less.