40results about How to "Improve surface protection performance" patented technology

The invention relates to the technical field of electric cars, in particular to an integrated water-cooled power battery box. The integrated water-cooled power battery box provided by the invention comprises a box cover, a box body and a temperature regulating power system, wherein the box body is made of an aluminum alloy material and is manufactured by an extrusion moulding technology; a circulating flow passage is formed in the wall of the box body; a circulating loop for a temperature regulating medium to flow circularly is arranged inside the wall of the box body; and the temperature regulating power system can drive the temperature regulating medium to circularly flow in the circulating loop. In such a way, a water cooling board and a battery box are designed in an integrated manner,a hollow aluminum alloy section is adopted to achieve lightweight design, mechanical properties such as strength and rigidity are met, the integrated water-cooled power battery box is simpler in structure, better in technical performance and smaller in occupied space, and the comprehensive cost can be reduced; the heat-dissipating, cooling and temperature-raising and heating functions can be achieved by using one set of temperature regulating power system, the integrated water-cooled power battery box is simpler in structure, more convenient and fast to use and smaller in occupied space, themanufacturing cost and the using cost can be reduced, and the heat-dissipating efficiency and the heating efficiency can be improved.

The invention relates to fiber reinforced flexible silica aerogel, which comprises glass fiber cloth reinforced ceramization phenolic resin sheets, glass fiber cloth reinforced epoxy resin sheets andflexible SiO2 aerogel and interlayer reinforced quartz fiber sewing threads. The inner part of the flexible silica aerogel is reinforced through interlayer overlapping of the glass fiber cloth reinforced epoxy resin sheets and the flexible SiO2 aerogel, the outer surface of the flexible silica aerogel is provided with the glass fiber cloth reinforced ceramization phenolic resin sheets used for strengthening and protecting the flexible SiO2 aerogel, and the quartz fiber sewing threads are used for through sewing the whole structure. The flexible silica aerogel has high strength and certain adhesive properties, the compressive strength of the flexible SiO2 aerogel is significantly improved, the problem of powder dropping of the aerogel is solved, and the interlayer bonding strength of the structure is improved, so that the reliability of aerogel application is greatly improved.

The invention discloses an accident fault-tolerant zirconium cladding tube protective coating, a manufacturing method and an application thereof. The protective coating comprises a Cr layer, the Cr layer is a columnar crystal structure, and a grain size distributed in a direction vertical to a columnar crystal growth direction ranges from 200 nm to 300 nm. Preferably, a thickness of the Cr layer is 15 to 25mum. The Cr layer manufactured by the method is compact in internal structure, and the grain size is 200-300nm by regulating a high-power pulse magnetron sputtering voltage so that the coating has excellent high-temperature water vapor oxidation resistance performance. Good surface protection performance is provided for a zirconium cladding tube under a condition of accident fault tolerance and occurrence of the accidents is avoided.

The invention discloses a normal / low-temperature chemical conversion solution for 35CrMnSi steel and a preparing method thereof. The conversion solution consists of the following components in percents by weight: 10-30% of nitric acid, 5-15% of phosphoric acid, 15-25% of zinc oxide, 1-5% of iron powder, 5-10% of a compound accelerant and the balance of water, wherein the compound accelerant is prepared from citric acid and chlorate. The preparing method comprises the following steps: (1), dissolving the zinc oxide in the nitric acid and the phosphoric acid; (2), then, adding the compound accelerant, and after fully dissolving, adding the water; and (3), adding the iron powder into a solution obtained in step (2), taking out the iron powder after curing, and regulating the pH value to 2.0 to 3.0. The normal / low-temperature chemical conversion solution for 35CrMnSi steel does not contain toxic components, the use method is simple and is easy to operate, energy consumption and production cost are low, one layer of even and dense conversion film consisting of 2-5mum flaky zinc phosphate crystals can be formed on the surface of a base body, and the corrosion resistance is great.

The invention discloses an impact-resistant corrosion-resistant powder paint for valves, which is prepared from the following raw materials in parts by weight: 20-30 parts of novolac epoxy resin, 15-25 parts of bisphenol A epoxy resin, 5-10 parts of ABS (acrylonitrile-butadiene-styrene) resin, 20-30 parts of barium sulfate, 3-5 parts of mullite fiber, 0.3-0.5 part of nano cerium oxide, 4-6 parts of aluminasol, 3-5 parts of water-based polyurethane emulsion, 3-5 parts of phenol curing agent, 0.5-1 part of disodium edetate, 0.5-1 part of castor oil polyethenoxy ether and 6-8 parts of film forming assistant. The powder paint for valves has excellent corrosion resistance and leveling property. The formed coating has the advantages of high combining capacity with the metal matrix, smooth surface, high flatness, low tendency to peeling and cracking, high flexibility, high impact resistance and high stability, and can perform favorable surface protection function.

The invention discloses a composite nanometer material with palladium coated with aluminum oxide and a preparing method of the composite nanometer material. A nanometer particle two-dimensional chain serves as the material, and the particle size of nanometer particles forming the nanometer particle two-dimensional chain is 6-80 nm. The nanometer particle two-dimensional chain is formed by coating palladium nanometer particles with aluminum oxide, wherein the particle size of the palladium nanometer particles is 5-50 nm, and the thickness of an aluminum oxide layer is 1-30 nm. The method includes the steps that a palladium target material is put into a stirred aluminum nitrate solution, lasers with the wavelength being 532 nm or 1064 nm, the repetition frequency being 1-20 Hz, the pulse width being 5-15 ns and the power being 40-120 mJ / pulse are used for irradiating the palladium target material for at least 20 min, and a mixed colloidal solution is obtained; and afterwards, the mixed colloidal solution is subjected to solid-liquid separation, washing and drying in sequence, and a target product is prepared. The composite nanometer material is long in hydrogenation and polymerization reaction service life and high in structure stability and can be extremely easily and widely applied to the fields of hydrogenation and polymerization reactions, gas sensors and surface enhanced Raman scattering in a commercialized manner.

The invention discloses a noctilucent identification tape and a preparation method thereof, and printed patterns give out light itself. The noctilucent identification tape and the preparation method are good in lighting effect, safe and environment-friendly in products and convenient to use. The noctilucent identification tape is divided into seven layers from the front face to the back face, namely a first transparent polyester film layer, a first ethylene (EVA) hot melting glue layer, printing paper, a second EVA hot melting glue layer, a second transparent polyester film layer, a tackiness agent layer and silicon coating protective paper which are sequentially arranged. The preparation method of the noctilucent identification tape comprises the following steps of coating EVA hot melting glue on the surface of a transparent polyester film to form a pre-coating film through an extrusion curtain coating process; coating the tackiness agent on a polyester face of the pre-coating film through a dry-type composite process, forming a back-glue pre-coating film with the silicon coating protective paper after drying; and vertically folding and winding EVA hot melting glue faces of the pre-coating film and the back-glue pre-coating film, and forming a back-glue film through cutting, burnishing and chamfering.

The invention provides a production method for a continuous functional composite material. The invention mainly aims to deeply improve and optimize a present production technology and produce two-layer and three-layer functional composite materials with higher applicability and higher bonding property. The product produced according to the method is capable of continuously and stably working at -20 DEG C to 100 DEG C; the product has multiple functions, such as vibration reduction, noise reduction, sound insulation, heat insulation and magnetism resistance; the product is a novel environment-friendly functional composite material and has wide application prospect.

The invention provides a cement pipe internal anticorrosion method, anticorrosion paint and a preparation method of the anticorrosion paint. According to the cement pipe internal anticorrosion method, epoxy resin coats the inside of a cement pipe, so that the inner surface of the cement pipe can be effectively prevented from fluid corrosion and erosion. Meanwhile, the anticorrosion paint can be used in the cement pipe internal anticorrosion method; in the anticorrosion paint, nanometer zinc oxide is used as a filler and is compounded with pigments and fillers such as epoxy resin and titanium dioxide, and an auxiliary agent and a curing agent to be used, so that the anticorrosion paint has good anticorrosion performance; meanwhile, excellent impact resistant performance and good adhesion performance are also realized. Further, according to the preparation method, the anticorrosion paint ingredient is used as a raw material; the preparation method has the advantages that the operation steps are convenient and fast; the prepared anticorrosion paint has excellent performance; the use effect is good, and the like.

The invention discloses multi-effect anti-fouling coating. The multi-effect anti-fouling coating is prepared from a component A and a component B; the component A is prepared from the following components in parts by weight: 40-45 parts of fluorine-silicon modified polyester resin, 0.5-2 parts of an anti-static agent, 0.5-2 parts of a hydrophobic restorer, 0.5-2 parts of an anti-mold and anti-algae agent, 0.5-2 parts of a leveling agent, 0.5-2 parts of a wetting dispersant and 2-5 parts of a defoaming agent; the component B is prepared from 30-50 parts of a polyisocyanate pre-polymer; the massratio of the component A to the component B is (4 to 10):1; and the fluorine-silicon modified polyester resin contains hydroxyls. Through the synergistic effect of the fluorine-silicon modified polyester resin, the polyisocyanate pre-polymer and the multiple functional additives, the multi-effect anti-fouling coating has the functions of corrosion prevention, fouling prevention, self-cleaning, scrawling prevention and pasting prevention, and has excellent overall performance. The invention further discloses a construction method of the multi-effect anti-fouling coating.

The invention discloses an indium oxide thin-film material modified with aluminium oxide-coated palladium nanoparticles and a preparation method and an application thereof. according to the material, an indium oxide monolayer porous thin-film is modified with 1-100 micrograms / cm<2> of aluminium oxide-coated palladium nanoparticles, wherein pore diameter of the porous thin-film is 50-5000 nm; film thickness is 10-5000 nm; particle size of the aluminium oxide-coated palladium nanoparticles is 12-160 nm; layer thickness of aluminium oxide is 1-30 nm; and particle size of palladium particles is 10-100 nm. according to the method, the indium oxide monolayer porous thin-film is firstly obtained by an in-situ growth method; then, a palladium target is placed into an aluminium nitrate solution, and the palladium target is irradiated by the use of laser at wavelength of 532 nm or 1064 nm so as to obtain a mixed colloidal solution; afterwards, the mixed colloidal solution undergoes solid-liquid separation and washing; the obtained aluminium oxide-coated palladium nanoparticles are dispersed in ethanol, and the indium oxide monolayer porous thin-film is coated with the above solution obtained so as to prepare a target product. The product can be widely used in fields of selective detection of ethanol gas and gas sensing.

The invention belongs to an aluminum alloy surface protection technology and in particular relates to a method for improving binding force of priming paint on aluminum alloy parts. The method comprises the following steps: uniformly polishing the surface of a machined part by using fine grit sandpaper under the condition that the tolerance of the part is not influenced and then polishing by using a sand felt so that a smooth base layer is exposed out of the surface of the part. Therefore, the lines on the surface of the part are disordered and the roughness of the base surface is improved so that a film is easily formed on the aluminum alloy base in chemical conversion treatment process, the appearance of the film layer is continuous and complete, and the binding force between the priming paint of the part and the base is effectively improved. The technology disclosed by the invention is easy to operate and low in cost, and some aircraft return parts to be repaired can be operated. Therefore, the difficulty in detaching the parts from the assembly is eliminated and the surface protection performance of the part can be improved. A protective effect which is the same as that of part dipping treatment can be achieved.

The invention discloses a halloysite nano-tube composite rattan handicraft product aqueous polyurethane anticorrosive paint, which is prepared from the following raw materials by weight: 0.5-1 part of halloysite nano-tubes, 0.3-0.5 part of sodium diethylhexyl sulfosuccinate, 10-15 parts of nanocellulose suspension with a solid content of 10-12%, 0.3-0.5 part of guar gum, 40-50 parts of an aqueous polyurethane resin, 0.5-1 part of octenylsuccinic anhydride, 4-6 parts of anhydrous ethanol, 0.5-1 part of a kathon anticorrosive agent, 2-4 parts of a bamboo vinegar liquid, 0.3-0.5 part of eucalyptus leaf oil, and 0.1-0.15 part of tea polyphenol. According to the present invention, the aqueous polyurethane anticorrosive paint has advantages of good corrosion resistance, high toughness, good binding property with rattan fiber, cracking resistance, shedding resistance, antibacterial effect, air purifying effect, green and environmental protection, safety, and health.

The invention discloses a waterborne polyurethane anticorrosive paint for a moisture-proof and mothproof rattan craftwork. The waterborne polyurethane anticorrosive paint is prepared by the following raw materials in parts by weight: 1-1.5 parts of nano silica hollow spheres, 0.3-0.5 part of camphor oil, 0.1-0.2 part of sandalwood oil, 10-15 parts of a nano cellulose suspension with a solid content of 10-12 percent, 0.3-0.5 part of guar gum, 40-50 parts of waterborne polyurethane resin, 0.5-1 part of octenyl succinic anhydride, 4-6 parts of anhydrous ethanol, 0.05-0.1 part of polyoxypropylene glycerol ether, 0.5-1 part of a Kathon preservative, 1-2 parts of rosin emulsion and 0.5-1 part of calcium sulfate whiskers. The waterborne polyurethane anticorrosive paint disclosed by the invention is good in corrosion resistance, high in toughness, good in binding property with rattan fibers and difficult to crack and fall off and simultaneously has good moisture-proof and mothproof properties and good durability.

The invention discloses a traction system for an elevator. The traction system comprises a traction machine mounted in an elevator shaft, a traction steel wire rope and a counterweight filler weight arranged below the traction machine; the traction system is characterized in that one end of the traction steel wire rope is fixed to the inner wall of the elevator shaft, and the other end of the traction steel wire rope is fixed to the counterweight filler weight, a surface treatment mechanism is arranged between the counterweight filler weight and a driving wheel, and a surface treatment mechanism is arranged between a guide wheel of a lift car and the driving wheel; each surface treatment mechanism comprises a spraying mechanism used for spraying a wax layer on the surface of the traction steel wire rope and a wax removal mechanism used for removing the wax layer on the surface of the traction steel wire rope; the wax removal mechanisms and the spraying mechanisms are sequentially arranged in the length direction of the traction steel wire rope, and each wax removal mechanism is arranged between the corresponding spraying mechanism and the driving wheel; and according to the traction system for the elevator, on the basis of not affecting friction force between the traction steel wire rope and the driving wheel, the surface layer protection performance of the traction steel wire rope is improved.

The invention discloses a dirt-resistant cane handicraft waterborne polyurethane anti-corrosion paint. The paint is prepared from, by weight, 40-50 parts of waterborne polyurethane resin, 0.1-0.15 part of polysorbate 80, 10-15 parts of nano-crystalline cellulose suspension with 10-12% solid content, 0.3-0.5 part of guar gum, 0.5-1 part of octenyl succinic anhydride, 0.5-1 part of texanol, 4-6 parts of ethanol, 0.5-1 part of casson preservative, 0.3-0.5 part of 13 (n-ethylperfluorooctanesulfonamido triethoxy silane and 0.05-0.1 part of chloririated paraffin-52. The waterborne polyurethane anti-corrosion paint has good anti-corrosion property, high toughness, good combination properties with rattan cane fiber and is not easy to crack and come off. Moreover, the waterborne polyurethane anti-corrosion paint has good waterproof, stain-resistance properties and is easy to clean.

The invention relates to a microcrystalline surface LED display screen, which comprises a PCB, LED lamp beads, a mask and a microcrystalline layer, and is characterized in that the LED lamp beads arearranged on the PCB in an array manner; lamp holes corresponding to the LED lamp beads are formed in the mask, and each LED lamp bead corresponds to one lamp hole and penetrates out of the lamp hole.The mask and the LED lamp beads are packaged on the PCB through the microcrystal layer, and glass beads are arranged in the microcrystal layer. The mask and the LED lamp beads are packaged on the PCBthrough the microcrystal layer, so that the waterproof and dustproof effects are realized, the wear resistance and scratch resistance can be realized, and the surface protection capability of the microcrystal surface LED display screen is greatly enhanced.

The invention discloses waterborne polyurethane antiseptic paint for yellowing-and-ageing resistant vine artware. The waterborne polyurethane antiseptic paint comprises, by weight, 10-15 parts of nano-cellulose suspensions with the solid content of 10-12%, 0.5-1 part of nano zinc oxide, 0.3-0.5 part of guar gum, 0.5-1 part of hydroxyl silicone oil, 40-50 parts of waterborne polyurethane resin, 0.1-0.15 part of nonylphenol polyoxyethylene ether, 0.5-1 part of octenyl succinic anhydride, 4-6 parts of absolute ethyl alcohol, 0.05-0.1 part of benzotriazole, 0.5-1 part of Kathon aseptic and 0.3-0.5 part of sodium salicylate. The waterborne polyurethane antiseptic paint has the advantages of good antiseptic performance, high tenacity, good combination performance with vine fibers, less proneness to cracking and shedding, high ultraviolet and ageing resistance, less proneness to yellowing and high appearance quality.

The invention discloses a high-hardness coating material for aluminum alloy protection and a preparation method and application thereof, and aims to provide a high-hardness coating material for aluminum alloy protection with a high protection effect and a preparation method and application thereof. The coating material is prepared from the following components: a fluorinated polyurethane type highpolymer material, an organic solvent, fluorinated graphene, tetrafluoroethylene dispersion liquid and polyimide fibers; wherein the percentage (mass) of the fluorinated polyurethane type high polymermaterial, the organic solvent, the fluorinated graphene, the tetrafluoroethylene dispersion liquid and the polyimide fibers is (25-50): (25-35): (5-10): (19.5-30.5): (0.5-2.5). The coating material has good comprehensive properties such as wear resistance, waterproofness and scratch resistance, and the surface protection effect of the aluminum alloy base material can be greatly improved.

The invention discloses a passivation treatment solution for improving the corrosion resistance of a metal surface. The passivation treatment solution comprises the following substances of sulfuric acid, citric acid, tartaric acid, nitric acid, hydrogen peroxide, sodium hydroxide, a silane coupling agent, konjac glucomannan, diethyl carbonate, methylN-phneylCarbamate, tetrabutyl titanate, ethyl alcohol and water. According to the passivation treatment solution, the protection effect on the metal surface is obviously improved, so that the corrosion resistance of the material is improved, the service life is prolonged, and the passivation treatment solution has great popularization and application values.

The invention discloses an anti-fake tracing package which comprises a package body, an opening, observation plates and a tracing patch. The opening is fixedly connected to the surface of the rear side of the package body. A circle of opening is distributed in the surface of the rear side of the package body. The observation plates are arranged at the left end and the right end of the middle of the package body in a nested manner. The tracing patch is closely attached to the middle of the top of the package body. A dampproof partition plate is embedded into the middle in the package body. A buffering pad is closely attached to the surface in the package body. The tracing patch further comprises anti-fake stickers which are closely attached to the front end and the rear end of the left sideof the tracing patch. A sticker is closely attached to the surface of the top of the tracing patch. Sealing strips are closely attached to the periphery of the tracing patch and located on the bottoms of the stickers. The whole anti-fake tracing package is concise in structure, has a good surface protecting effect and has high practicality.

The invention discloses environmental-friendly mosquito-repellent waterborne polyurethane anti-corrosion paint for cane handicraft. The anti-corrosion paint is prepared from the following raw materials in parts by weight: 1-1.5 parts of nano-silica hollow spheres, 0.1-0.15 part of soapberry extract, 10-15 parts of nano-crystalline cellulose suspension with solid content of 10-12%, 0.3-0.5 part of guar gum, 40-50 parts of waterborne polyurethane resins, 0.5-1 part of octenyl succinic anhydride, 0.2-0.4 part of zanthoxylum oil, 0.3-0.5 part of blumea oil, 4-6 parts of absolute ethyl alcohol, 0.5-1 part of terpilenol and 0.5-1 part of a Kathon preservative. The waterborne polyurethane anti-corrosion paint disclosed by the invention is good in anticorrosive property, high in toughness, good in bonding performance with cane fibers and difficult to crack or drop and has good mosquito-repellent performance, safety and environment friendliness.

The invention discloses a dragging system for an elevator. The dragging system comprises a dragging system, a dragging steel wire rope and a counterweight filler weight. The dragging system is characterized in that surface processing mechanisms for processing the surface layer of the dragging steel wire rope are respectively arranged between the counterweight filler weight and a driving wheel, as well as between guiding wheels of a lift car and the driving wheel; each of the surface processing mechanisms comprises a spraying mechanism and a wax removing mechanism; an annular groove allowing the dragging steel wire rope to be surrounded on the corresponding guiding wheel is formed in an outer periphery wall of the corresponding guiding wheel; at least three clamping grooves formed by internal tangency in the radial direction of the corresponding guiding wheel are formed in the position at the bottom of each annular groove; and a clamping block is arranged in the corresponding clamping groove, and the dragging steel wire rope is abutted to or separated from the upper end surfaces of the clamping blocks along with the rotation of the guiding wheels. According to the dragging system for the elevator provided by the invention, based on the condition that frictional force between the dragging steel wire rope and the driving wheel is not influenced, the protective performance of the surface layer of the dragging steel wire rope is improved.

The invention belongs to the technical field of composite metal plate production, and relates to a production process of a metal-based composite plate. An upper layer metal belt material and a lower layer metal belt material are subjected to surface treatment, surface activation treatment and macromolecular resin coating; then, the materials enter a drying furnace to complete solvent volatilization and macromolecular resin curing; environmental-friendly plastics such as PE and PP are clamped between the two layers of metal plate materials to complete the compounding; next, through leveling, trimming and fixed ruler shearing, the compounded metal-based composite plates are collected into plate materials. A product produced by the process can be used for a long time at normal temperature environment; the vibration reduction and noise reduction performance are better than those of the conventional metal plate material and the double-layer metal composite plate; the composite plate belongsto a kind of novel environment-protection and environmental-friendly metal-based composite plate, can be widely applied to building decoration industry and meets the silence requirements in the building decoration industry.

The invention discloses an indium oxide thin-film material modified with aluminium oxide-coated palladium nanoparticles and a preparation method and an application thereof. according to the material, an indium oxide monolayer porous thin-film is modified with 1-100 micrograms / cm<2> of aluminium oxide-coated palladium nanoparticles, wherein pore diameter of the porous thin-film is 50-5000 nm; film thickness is 10-5000 nm; particle size of the aluminium oxide-coated palladium nanoparticles is 12-160 nm; layer thickness of aluminium oxide is 1-30 nm; and particle size of palladium particles is 10-100 nm. according to the method, the indium oxide monolayer porous thin-film is firstly obtained by an in-situ growth method; then, a palladium target is placed into an aluminium nitrate solution, and the palladium target is irradiated by the use of laser at wavelength of 532 nm or 1064 nm so as to obtain a mixed colloidal solution; afterwards, the mixed colloidal solution undergoes solid-liquid separation and washing; the obtained aluminium oxide-coated palladium nanoparticles are dispersed in ethanol, and the indium oxide monolayer porous thin-film is coated with the above solution obtained so as to prepare a target product. The product can be widely used in fields of selective detection of ethanol gas and gas sensing.

The invention relates to the technical field of flashing plates, and discloses an arc-shaped flashing aluminum plate a good installation effect and a high sealing performance. The arc-shaped flashing aluminum plate comprises a plate body; the plate body comprises a first installation plate, a first screw hole, a second installation plate, a second screw hole, a main plate and a bonding layer; the first screw hole is formed in the first installation plate; the right side of the first installation plate is fixedly connected with the main plate; and the right side of the main plate is fixedly connected with the bonding layer. According to the arc-shaped flashing aluminum plate the good installation effect and the high sealing performance, through the cooperative work of first fixing screws, a first mortar plaster, the plate body, a first base plate, a first sealing plate, second plaster mortar, a second sealing plate, a second base plate, a protective film, mortar pointing joints and second fixing screws, the installation effect of the flashing aluminum plate is more stable, and the sealing performance is higher; and the overall protection effect is more comprehensively improved through more stable installation effect and higher sealing performance, and the service life of a wall is better prolonged through improvement of the protection effect.

The invention discloses a multi-effect antifouling paint, which comprises component A and component B. The component A comprises the following components in parts by weight: 40-45 parts of fluorosilicon modified polyester resin, 0.5 parts of antistatic agent ~2 parts, 0.5~2 parts of hydrophobic recovery agent, 0.5~2 parts of anti-mildew and anti-algae agent, 0.5-2 parts of leveling agent, 0.5-2 parts of wetting and dispersing agent and 2-5 parts of defoaming agent; Component B includes 30-50 parts of polyisocyanate prepolymer; the mass ratio of the component A to the component B is 4-10:1; the fluorosilicon-modified polyester resin contains hydroxyl groups. The multi-effect protective coating not only has the functions of anti-corrosion, anti-fouling self-cleaning, anti-graffiti, and anti-sticking through the synergistic effect of fluorosilicon modified polyester resin, polyisocyanate prepolymer and various functional additives, but also has comprehensive performance excellent. The invention also discloses a construction method of the multi-effect antifouling paint.