66 results about "Absorptance" patented technology

This disclosure relates generally to a patterning structure including an underlayer and an imaging layer, as well as methods and apparatuses thereof. In particular embodiments, the underlayer provides an increase in radiation absorptivity and / or patterning performance of the imaging layer.

The invention relates to conductive paste and a preparation method thereof, a solar cell and a preparation method thereof, and a photovoltaic module. The conductive paste comprises 82%-88% of metal powder, 1%-5% of glass powder, 8%-15% of an organic carrier, 0.5%-3% of a wave-absorbing material and 0.1%-1% of a polymer pore-forming agent, and the wave-absorbing material can absorb laser and release heat. During laser-assisted sintering treatment, the wave-absorbing material can efficiently absorb laser energy and instantly release heat, so that the surrounding polymer pore-forming agent is quickly gasified. After the polymer pore-forming agent is gasified, a cavity structure is formed in the conductive slurry, a multi-reflection cavity of light is formed, laser which is subsequently transmitted in is reflected for multiple times in the cavity, a light path is prolonged, and the absorption rate of laser energy is greatly improved. Due to the high absorptivity of the laser, the laser power required by good ohmic contact is formed, the energy consumption is reduced, and the damage to the surface of the battery is reduced.

The application belongs to the field of turbine blade thermal barrier coating of an aero-engine. Specifically, it is a structure design, a preparation method and a prepared coating of a double-layer radiation-resistant thermal barrier coating with a high-reflection layer and a high-absorption layer. The coating comprises a high-absorption layer and a high-reflection layer. The high-absorption layer can absorb part of the energy of photon radiation and re-emit it into the environment, while relying on a cooling gas film to quickly remove heat. Part of the energy of the photon radiation is reflected by the high-reflection layer again to the high-absorption layer after passing through the high-absorption layer, and the process of absorption-emission-cooling gas film heat dissipation is repeated. Within a set temperature range, the absorption rate of the high-absorption layer is determined based on the temperature difference requirement between the inner and outer surfaces of the thermal barrier coating, and the high-absorption layer material is determined based on the absorption rate. The application greatly reduces the radiation heat flow penetrating the coating, avoids the direct heating of the high-temperature alloy by infrared radiation, and significantly improves the heat insulation capacity of the thermal barrier coating and the service life of the turbine blade.

The application provides an antifouling coating material, an antifouling coating and a preparation method and application thereof. The antifouling coating prepared from the antifouling coating material provided by the application has a water contact angle of 105.8-161.5 degrees and a sliding angle of 1.5-24.1 degrees in a wavelength range of 200-2500 nm; a light absorption rate of 65.7-98.3 %; and a maximum light-heat surface temperature of 45.1-82.8 DEG C under 1 solar light intensity. Moreover, the antifouling coating has synergistic antifouling of superhydrophobic low adhesion and biological repellence, wide-spectrum high-efficiency and controllable light-heat antifouling capacity, all-weather antifouling capacity facing the air-water interface of the sea, and excellent mechanical durability and light-heat / wetting performance stability.

To provide an exterior laminate that can be used as an exterior component and is capable of sufficiently suppressing heat accumulation due to radiant heat such as sunlight. [Solution] An exterior laminate 10 is disclosed, having, in order from the surface side, a) a transparent film layer 1 containing an acrylic resin, c) a printed layer 2, and b) a colored film layer 3 containing a polyvinyl chloride resin, wherein the printed layer 2 of c) does not contain carbon black, the solar transmittance of the printed layer 2 of c) is 70% or more, and the solar absorptance is 20% or less. Preferably, the printed layer 2 of c) contains a perylene-based colorant and / or a phthalocyanine-based colorant.

The invention discloses a Ni3Al-PPy composite wave-absorbing material as well as a preparation method and application thereof, and belongs to the technical field of electromagnetic wave-absorbing materials. The Ni3Al-PPy composite wave-absorbing material with a core-shell structure is successfully synthesized by combining a thermit reaction with a chemical oxidation polymerization method and hydrochloric acid modification. By regulating and controlling the addition amount of the pyrrole monomer in the range of 0.25-0.75 mL, the continuous regulation and control of the thickness of the PPy shell layer from 0.22 [mu] m to 0.31 [mu] m is realized. When the thickness of a PPy shell layer is 0.27 mu m and the matching thickness of the composite wave-absorbing material is 3.0 mm, the minimum reflection loss and absorptivity gt of-40.0 dB are obtained at 9.27 GHz; and when the matching thickness is 2.0 mm, the effective absorption bandwidth reaches 3.02 GHz. According to the invention, the effect of the shell layer thickness in regulating and controlling the performance of the wave-absorbing material with the core-shell structure is illustrated, and a feasible strategy is provided for designing a high-performance light-weight wave-absorbing material with adjustable electromagnetic parameters and enhanced durability.

The invention relates to a spectrum selective absorbing coating driven by anion and cation co-entropy engineering. The coating is composed of a polished stainless steel heat absorber substrate, a (HfZrTiTaMo) B absorbing layer and a Si3N4 antireflection layer. And the absorption layer is obtained by sputtering high-entropy boride targets with equal molar ratios under different parameters through radio frequency reaction magnetron sputtering. The preparation process is simple, the cost is low, the absorption rate of the prepared coating is larger than or equal to 0.91, the emissivity is smaller than or equal to 0.13 under the condition of the atmospheric quality factor AM1.5, and the coating has the good spectrum selection characteristic and has the important application value in the fields of solar photo-thermal power generation, photo-thermal sterilization, seawater desalination, water evaporation and deicing.

The application discloses a heat control device and method for a flexible thin film antenna in space, which is mainly used for providing heat control for large flexible antennas such as phased array radars in space. A solar shield with high infrared emissivity, low solar absorptivity and microwave permeability is arranged on the front surface of the antenna, and when the back surface of the antenna is irradiated by the sun, the solar shield can quickly dissipate heat by using the high infrared emissivity, and when the front surface of the antenna is irradiated by the sun, the solar shield can prevent the antenna from absorbing too much heat and making the temperature of the antenna too high by using the low solar absorptivity; an insulating layer and a low solar absorptivity coating are arranged on the back surface of the antenna, and when the back surface is irradiated by the sun, the low solar absorptivity coating can reflect most of the solar heat, and when the back surface is in a shadow area, the insulating layer can prevent the temperature of the antenna from being too low. Therefore, the antenna can always be in a relatively suitable temperature range in the complex and changeable space orbit thermal environment. The application has the characteristics of strong adaptability and wide applicability.

The application discloses a kind of perfect cutoff absorber of metasurface based on nano round structure, adopt nanometer cylinder and ring array grown on silicon dioxide, two groups of ring structure are respectively selected using dielectric material gallium arsenide and silicon.Optimizing structure parameter, wavelength from ultraviolet to mid-infrared, 0.913 average absorption is realized in absorption band 100-710nm, and average absorption is only 0.02 in non-absorption band 1260nm-20μm wave band.ER is 9.6dB, ED is 0.81, and CS is 0.0015nm ‑1 The perfect cutoff absorber provided by the application has exactly this spectral selectivity, which provides an effective method for designing ideal solar heat absorber, which has important application in the field of renewable energy, such as solar thermal photovoltaic and solar thermal energy application.

The application discloses a multilayer film compatible with H, K, medium-wave infrared and long-wave infrared wave band stealth and radiation heat dissipation. The multilayer film comprises a substrate, a metal reflection layer, a photonic crystal layer fusing loss medium and an H and K wave band anti-reflection layer, the absorptivity of the H and K wave band is greater than 0.5, the emissivity of the medium-wave infrared and long-wave infrared wave band is lower than 0.5, and the emissivity of the very long-wave infrared wave band is greater than 0.5; the photonic crystal layer fusing loss medium is a multilayer structure and is formed by alternately stacking medium layers of multiple high and low refractive index medium materials. The multilayer film can realize the stealth of solar radiation and thermal radiation and has effective radiation heat dissipation heat management capability at the same time, and can be widely applied to the fields of aviation, spaceflight and the like.

The invention relates to a near-blackbody high-entropy inverse spinel oxide material, the general formula of the material is (A1xA2yA3zA4uA5v) 3O4, A1, A2, A3, A4 and A5 are any five elements of Fe, Ni, Co, Cr, Mn, Cu and Ti, x, y, z, u and v are equal or approximately equal, and x + y + z + u + v = 1; the structure of the material belongs to a cubic system and has an inverted spinel crystal structure, and the space group of the material is Fd-3m. Meanwhile, the invention also discloses a preparation method of the material. The method is simple to operate and short in production cycle, the obtained high-entropy inverse spinel oxide material has high solar absorptivity and infrared emissivity, the radiation curve of the high-entropy inverse spinel oxide material is close to an ideal black body radiation curve, and the high-entropy inverse spinel oxide material can be widely applied to the fields of radiation heating, human body heat management, aerospace heat dissipation, photovoltaic device cooling and the like.

The invention relates to a high-entropy two-dimensional transition metal MXene broadband light-absorbing material which is composed of an M-layer element, an A-layer element and graphite powder, an A-layer Al element is etched through a LiF-HCl mixed solution with the mass concentration of 40% to form a two-dimensional layered structure, and the chemical general formula of the material is M3C2; wherein the elements of the M layer are any five metal elements of Ti, Zr, Nb, Mo, Hf and W, and the metal atoms are in an equal molar ratio; and the element of the A layer is Al. Meanwhile, the invention also provides a preparation method of the material. The preparation method is easy, high in repeatability and high in production efficiency and can be used for industrial large-scale production, the solar energy absorption rate of the prepared broadband light absorption material within the waveband range of 0.3-2.5 microns is 0.891-0.910, and the broadband light absorption material can be widely applied to solar photo-thermal conversion materials.

The utility model relates to the technical field of sunglass polaroid testing, in particular to a sunglass polaroid ultraviolet absorptivity testing device which comprises a base, an ultraviolet intensity detection sensor is fixedly connected to the top of the base, and electric push rods are fixedly connected to the two sides of the top of the base. Clamping frames are fixedly connected to the output ends of the opposite sides of the two electric push rods, a control mechanism is fixedly connected to the rear side of the top of the base, and a control frame is fixedly connected to the top of the control mechanism. The control mechanism is matched with the control frame to push the adjusting rod, the fixing frame is controlled by the adjusting rod and the mounting plate to move, the fixing frame is matched with the rollers to enable the integrated light source translation mechanism to slide on the surface of the arc-shaped track, and the integrated light source translation mechanism is adjusted to different use angles. The method and the device are used for simulating irradiation of the polaroid at different angles in a real scene and improving the accuracy of test data of the sunglasses polaroid.

This invention relates to the field of window spectral characteristic calculation, specifically to a method, system, and storage medium for calculating the spectral characteristic curve of an energy-saving window. The calculation method involves iterating through the transmittance, reflectance, and absorptance of a reference glass at wavelength λ, calculating the total annual energy consumption of air conditioning and lighting caused by windows facing the corresponding direction in the building, and obtaining the transmittance at the lowest total energy consumption at wavelength λ. 、 Reflectance and absorptivity are determined as the optimal spectral characteristic parameters of the glass at wavelength λ. After traversing the radiation band range, the optimal spectral characteristic parameters for different wavelengths are fitted into a band-based continuous curve, yielding the optimal spectral characteristic curve for the corresponding window orientation of the building in the local area. This not only provides quantitative basis for architects to scientifically select window glass, but also enables refined product development for different regions and building orientations, minimizing building energy consumption while ensuring indoor light and heat comfort.

The invention provides an infrared absorption substance, a preparation method thereof and ink. The preparation method of the infrared absorption substance comprises the following steps: preparing a first solution, a second solution and a third solution, mixing the first solution, the second solution and the third solution to obtain a mixed solution, and standing the mixed solution according to a preset standing duration; the first solution contains copper phosphate, the second solution contains sodium tungstate dihydrate, and the third solution contains cesium carbonate and citric acid; synthesizing the mixed solution by using a hydrothermal synthesis method to obtain a solid-liquid mixture; and carrying out water washing, alcohol washing, centrifugal separation and drying on the solid-liquid mixture to generate an infrared absorption substance, so that the infrared absorption substance has an infrared absorption rate of 85% or above at the infrared band of 850-1250 nm.

The invention relates to a sunscreen fiber, a preparation method thereof and a radiation refrigeration fabric. The sunscreen fiber comprises a core layer and a skin layer coating the surface of the core layer, wherein the core layer comprises a carbon-based nano material, the skin layer comprises radiation refrigeration particles, the absorptivity of the carbon-based nano material to sunlight at the wave band of 0.3-2.5 microns is a, the mass fraction of the carbon-based nano material in the core layer is m1, the atmospheric window emissivity of the radiation refrigeration particles at the wave band of 8-13 microns is b, and the sunlight reflectivity of the radiation refrigeration particles at the wave band of 0.3-2.5 microns is c, the mass fraction of the radiation refrigeration particles in the skin layer is m2, and a, b, c, m1 and m2 meet the following condition that c is larger than or equal to 88%. The sunscreen fiber has excellent sunlight total spectrum reflection performance and shading performance, and the radiation refrigeration fabric prepared from the sunscreen fiber as a raw material has extremely low sunlight transmittance, so that a better radiation refrigeration effect can be achieved.

The invention discloses a heat absorber enhanced heat transfer design method based on the effective absorptivity of solar flow, and belongs to the technical field of tower type photo-thermal power stations. Aiming at the problems of large surface temperature gradient, large heat loss and relatively low light-heat conversion efficiency of a chloride heat absorber, the method comprises the following steps of: constructing an optical model by adopting a Monte Carlo ray tracing method through a grid discrete heat absorber to obtain annual average solar flow distribution, and establishing a flow and heat transfer model to calculate annual average values of efficiency, temperature and heat loss; and solving the annual average solar energy flow effective absorptivity alpha (i, j) of each grid, taking a truncation index beta = alphamax-5% as a criterion, only arranging a spiral twisted strip in a high-absorption area in which alpha (i, j) is greater than beta, and determining the arrangement length of the twisted strip through performance calculation and iterative optimization. Fine design of the spiral twisted belt in the chlorate heat absorber is achieved, heat loss is reduced while balance among efficiency, flow heat transfer performance and flow resistance is achieved, light-heat conversion efficiency is effectively improved, and the spiral twisted belt is suitable for optimization of the chlorate heat absorber of the tower type photo-thermal power station.

The application provides a kind of glass that changes color and absorbs heat prepared by using iron-containing dust sludge of Baotou Steel, and the glass composition includes the following components by weight percentage: SiO2: 60-80%; iron-containing dust sludge: 10-20%; SnO2: 0.8-5%; Si: 0.1-5%; Na2CO3: 1-15%; CeCO3: 0.5-1%; H3BO3: 2-10%; NaCl: 1.5-5%; MgCO3: 2-6%; ZnO: 3-5%; LaCO3: 5-10%; AgNO3: 0.5-5%; KCl: 2.5-8%. The glass described in the application has an ultraviolet and infrared absorption rate of more than 90% before changing color, and a visible light transmittance of more than 70.0%.

The application discloses an ultrablack coating with wide-angle absorption and a preparation method and application thereof, and belongs to the technical field of ultrablack coatings and preparation thereof. The application solves the problem that the existing ultrablack coating cannot present extremely low scattering and high absorption under large-angle incident light. In the application, carbon black is used as an absorbent, a high-temperature-resistant silica sol solution is used as a binder, and a one-step sintering method is adopted to form a stable structure and construct an ultrablack coating with a forest-like light trap array structure. The forest-like array structure on the surface of the ultrablack coating significantly changes the refractive index of the coating surface, thereby reducing the surface optical reflection; the surface forest-like light trap structure is closely arranged, can make the light incident from each angle to reflect back and forth in the structure, and then maximally absorbs the incident light, realizes stable high light absorption under wide angles, makes the reflectivity of the ultrablack coating not obviously change with the angle of incident light, and improves the deep space exploration precision of a space optical system.

Provided are an infrared absorber having extremely low reflectivity in the wavelength band of infrared rays, a method for manufacturing the same, a black-body radiation device, and a radiative cooling device. Provided is an infrared absorber 10 provided with: an absorption layer 11 comprising carbon black and a resin; and, on the absorption layer 11, a surface layer 12 that comprises a resin including essentially no pigment and that has an optical confinement structure 13 in which a plurality of minute projections are formed on the surface thereof, the hemispherical total reflectivity of the infrared absorber 10 in infrared wavelengths of 5-15 μm being 0.2% or less. Further provided are a method for manufacturing the infrared absorber, a black-body radiation device, and a radiative cooling device.

To reduce labor when preparing a colored pattern in advance for estimating the kind of a light source.SOLUTION: The color sample 10 has sample color regions 12B1, 12B2, 12B3, 12B4, 12B5, 12BH, 12RGB, 12V1, and 12V2 corresponding to the observation result of the color of the illumination target 1 illuminated with illumination light L close to any one of a plurality of types of illumination light (CIE LED illumination conditions). However, in the irradiation target 1, the absorbance of blue, green, and yellow light is higher than the absorbance of red and purple light, and the reflectance of red and purple light is higher than the reflectance of blue, green, and yellow light. Further, the illumination light has types BH and RGB in which the relative brightness takes the maximum value in red, types V1 and V2 in which the relative brightness takes the maximum value in purple, and types B1, B2, B3, B4, and B5 in which the relative brightness takes the maximum value in blue.SELECTED DRAWING: Figure 3

The invention relates to the technical field of electromagnetic wave absorption devices, in particular to a multifunctional metamaterial perfect absorber and a manufacturing method thereof. The invention provides a multifunctional metamaterial perfect absorber and a manufacturing method thereof. The absorber comprises a silicon substrate layer, an adhesion chromium layer, a silicon dioxide thin film spacing layer, a gold thin film spacing layer, a broadband absorption metasurface and a narrowband absorption metasurface. The zirconium nitride concentric ring array is arranged on the broadband absorption metasurface, and the average absorption rate in the visible to near-infrared region wave band is as high as 97.48%; the narrow-band absorption metasurface is provided with a 4 * 4 grid array formed by zirconium nitride, and has 99.99% ultrahigh narrow-band absorption and high refractive index sensitivity. The material has excellent refractive index sensing performance and high thermal chemical stability of the zirconium nitride material, is suitable for the fields of solar energy collection, biosensing, environmental protection and the like, and remarkably improves the energy collection efficiency and the sensing sensitivity.

There is a very good linear relationship between the absorptivity (A) of a fabric sample to UV-Vis light and the surface concentration C of an antimicrobial agent on the fabric sample. On this basis, provided in the present invention is a method for estimating antimicrobial efficacy of a fabric sample, the method comprising: preparing antimicrobial agents of different concentrations (C), and respectively applying the antimicrobial agents to different fabric sheets to obtain fabric samples; measuring the absorptivity (A) of the fabric samples to radiation of a certain wavelength; measuring antimicrobial rates (y) of the fabric samples, to which the antimicrobial agents of different concentrations (C) are applied, against a certain microorganism; and fitting the antimicrobial rates (y) of the fabric samples and the absorptivity (A) of the fabric samples to radiation of a certain wavelength, so as to obtain a relationship between the antimicrobial rates (y) and the absorptivity (A) of the fabric samples to radiation of the wavelength, wherein the antimicrobial rate (y) of the fabric sample to be tested can be calculated by using the relationship between the antimicrobial rates (y) and the absorptivity (A) of the fabric samples to radiation of the wavelength and on the basis of the absorptivity (A1) of the fabric sample to be tested to radiation of the wavelength.

The application relates to a spinel-perovskite dual-phase high-entropy ceramic powder material, which has a chemical formula AMn x O y wherein A is three transition metal elements selected from Cu, Ni, Co, Zn and Mg and one rare earth element selected from La, Pr and Nd, the elements are in equal molar ratio, 1 < x < 2 and 3 < y < 4, the material has a face-centered cubic crystal structure spinel phase and a perovskite phase. Meanwhile, the application also discloses a preparation method of the high-entropy ceramic powder material. The high-entropy ceramic powder material has the characteristics of two-phase coexistence, high purity, small particle size (100-400 nm) and uniform element distribution, and has excellent solar absorptivity (>0.87), infrared emissivity (>0.90) and high-temperature thermal stability (1600 DEG C), and can be widely used in the field of high-temperature thermal radiation, including aerospace, industrial kiln, power station boiler and the like, as an infrared radiation material and a solar energy absorption material.

The application discloses a kind of super material broadband solar absorber, belong to super material optical device technical field.The absorber adopts whole refractory material system, only by chromium (Cr) and silicon dioxide (SiO2) is formed, overall is periodic inverted hollow right square prism structure, system is divided into upper and lower two parts: the upper half is the periodic cyclic structure of SiO2 and Cr composition;Lower half is SiO2 dielectric layer and Cr reflection layer;From top to bottom, it presents the periodic hollow inverted right square prism structure.The application realizes 97.26% average absorption rate in 250-2500nm wavelength range, energy absorption rate is as high as 97.96% under AM1.5 standard solar irradiation condition, while the absorber has excellent polarization insensitive characteristics, simple structure, excellent thermal stability, can be widely used in solar energy collection, optical stealth and other fields.

The objective of this invention is to provide an infrared reflector that can achieve both suppression of color and appearance defects and heat shielding properties. [Solution] The device has an infrared reflective layer and a light-adjusting layer, and the saturation C of the reflected light when light is incident from the light-adjusting layer side at an incident angle of 60°. * R An infrared reflector characterized in that the value is between 0 and 10, and the average light absorption rate Abs in the 800nm ​​to 1400nm wavelength range, calculated by the following formula 1, satisfies 0% ≤ Abs ≤ 30%. Formula 1: Abs=100-TR T: Average transmittance of light in the 800nm ​​to 1400nm wavelength range when light is incident perpendicularly to the surface from the dimming layer side. R: Average reflectance of light in the 800nm ​​to 1400nm wavelength range when light is incident perpendicularly to the surface from the dimming layer side.

Disclosed in the present is materials and methods for delivering substances to plants. The invention describes a method to enhance substances uptake by plants using selective ablation of light pulses to remove the wax cuticle on a large scale in fields, comprising steps of light selective ablation of wax based optical properties of leaves, using lasers, pulsed lamps or other light sources like solar filtered solar light to remove the wax selectively without damage the leaves. Also disclosed is material for enhancing substances uptake by plants using selective ablation of light pulses to remove the wax cuticle, comprising selective ablation of light pulses of a wavelength of about 532 nm or within the range 495 to 570 nm.

The application discloses a polyethylene film with selective spectral characteristics and a preparation method and application thereof. The preparation method of the selective spectral characteristic polyethylene film of the application is characterized in that sodium chloride powder is mixed with polyethylene powder, and then melt extrusion granulation is carried out, sodium chloride-polyethylene granules are cast into a film, and then sodium chloride is dissolved in clean water, and the polyethylene film with selective spectral characteristics is obtained through drying. The polyethylene film has selective spectral emissivity and selective spectral reflectivity; in the sunlight band, the spectral reflectivity of the polyethylene film is high, and the spectral absorptivity is low, and the average absorptivity is 0.25; in the atmospheric window band 1-13 mu m, the spectral absorptivity (emissivity) of the polyethylene film is high, and the average absorptivity (emissivity) is 0.11.

The invention discloses a film system structure with functions of high solar absorption, high middle and far infrared transmission and high microwave transmission. The film system structure sequentially comprises a solar antireflection layer, a loss type Fabry-Perot cavity absorption layer, an infrared refractive index matching antireflection layer and a substrate layer from top to bottom, the solar anti-reflection layer has low reflection on a solar spectrum band; the solar anti-reflection layer, the loss type Fabry-Perot cavity absorption layer and the infrared refractive index matching anti-reflection layer are all highly transparent to middle and far infrared bands and microwaves. According to the invention, a cascade absorption cavity for sunlight and a refractive index matching structure for infrared light are constructed by using optical loss differences of materials in different wavebands. The absorptivity in the solar spectrum (AM1.5 or AM0) can exceed 0.9, providing a dark black appearance; meanwhile, high transmissivity is kept in two key wave bands of MWIR and LWIR, and the variable emissivity thermal control capability of a bottom-layer SRD device is perfectly kept.

The application discloses a kind of nanofiber-based materials with dual-mode thermal management and health detection function and its preparation method and application, belong to nanometer material technical field.The application integrates radiation heating nanofiber, radiation cooling nanofiber, fiber-based strain sensor and temperature sensor into one body.Radiation cooling layer is composed of TPU nanofiber with high mid-infrared emissivity and high reflectivity.Radiation heating layer is composed of CNT / TPU nanofiber with high absorptivity.The strain sensing layer with high sensitivity of wrinkle structure and crack structure is sandwiched between radiation cooling layer and radiation heating layer, which can monitor human respiratory signal in a non-restricted manner.The temperature sensing layer is directly printed on the TPU nanofiber layer by ink direct writing 3D printing technology.Benefiting from the network structure of TPU nanofiber, the material has excellent waterproofness and air permeability, and can be worn comfortably for a long time.