Carbon fibers(CFs) are widely used in cutting-edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus,superior corrosion and friction resistances,excellent the...
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Carbon fibers(CFs) are widely used in cutting-edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus,superior corrosion and friction resistances,excellent thermal stability,light weight,and high electrical ***,their natural ultra-black appearance is difficult to meet the aesthetic needs of today' s civilian sector and the need for optical stealth in the military *** addition,conventional coloring methods are difficult to effectively adhere to CF surfaces due to high crystallinity and highly inert surface caused by their graphite-like *** this work,inspired by the nacre structural color of pearls,colored CFs with 1D photonic crystal structure are prepared by cyclically depositing amorphous(Al2O3+TiO2) layers on the surface of carbon CFs through atomic layer deposition(ALD).The obtained CFs exhibit brilliant colors and excellent environmental durability in extreme ***,the colored CFs also exhibit high EMI shielding effectiveness(45 dB) and optical stealth properties,which can be used in emerging optical devices and electromagnetic and optical stealth equipment.
Efficient and stable electrocatalyst for oxygen evolution reaction(OER)in acidic environment is vital for polymer electrolyte membrane water electrolysis(PEMWE).In this work,we have devised the formation of heterostru...
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Efficient and stable electrocatalyst for oxygen evolution reaction(OER)in acidic environment is vital for polymer electrolyte membrane water electrolysis(PEMWE).In this work,we have devised the formation of heterostructured RuO_(2)/MnO_(2)with nanoflower structure for acidic OER *** to commercial RuO_(2),the overpotential at 50mA/cm^(2)is decreased by 36 mV,corresponding to a 3.7-fold better mass *** boosted acidic OER performance is attributed to the heterostructure inducing more electrons are filled in e_(g)orbital of Ru atom triggering a better deprotonation of bridge oxygen atom in Ru-O_(bri)-Mn structure evidenced by pH-independent cyclic voltammetry ***,RuO_(2)/MnO_(2)sustains its acidic OER activity within 20 h,longer than commercial RuO_(2).The membrane electrode assembly(MEA)test suggests than only 2.18 V is required to achieve a current density of 5 A/cm^(2).The theoretical calculation reveals that the e_(g)filling of Ru atom is increased from 2.18 to 2.39 after MnO_(2)incorporation,reducing the energy for the formation of∗OOH moiety.
advanced aerogel fibers possess numerousadvantages amalgamating the attributes of aerogels and fibermaterials, rendering them invaluable in the realm of thermalmanagement and regulation. However, the achievement ofrob...
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advanced aerogel fibers possess numerousadvantages amalgamating the attributes of aerogels and fibermaterials, rendering them invaluable in the realm of thermalmanagement and regulation. However, the achievement ofrobust mechanical properties and increased temperaturestability is still a major challenge for the majority of aerogelfibers. Herein, SiO_(2)-Kevlar hybrid aerogel fibers with bioniccore-shell structure were prepared by reaction spinning andweaved into fabric. Kevlar nanowires dispersion is pumpedinto a bath comprising a self-synthesized silica sol, whichfacilitates the hybridization of biphasic aerogels through thegel reaction. Precise control over the diameter (200-800 μm)and structure of the wet gel fibers was achieved throughmeticulous adjustment of the spinning solution composition and spinning parameters. Subsequent freeze-drying processfacilitates the formation of a core-shell hybrid structure, in which the SiO_(2) aerogel layer effectively encapsulate the Kevlaraerogel core fiber. Taking full advantage of the mechanical properties of the Kevlar core fiber, the resulting SiO_(2)-Kevlaraerogel fibers exhibit commendable weaving characteristics (51.8 MPa). Furthermore, SiO_(2)-Kevlar aerogel fabrics exhibitenhanced thermal insulation characteristics with a thermal conductivity of 0.037 W/(m·K). As a result of the presence ofexternal SiO_(2) aerogel layer, the overall temperature resistance performance of the SiO_(2)-Kevlar fabric reach up to 700 ℃.
When the protective and protected systems are detached,the former can be allowed to absorb the kinetic energy of the impacting projectile through large deformation without considering the back face signature of the **...
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When the protective and protected systems are detached,the former can be allowed to absorb the kinetic energy of the impacting projectile through large deformation without considering the back face signature of the *** paper presents a novel double-face knitted fabric(DFKF)designed for this very impacting *** tests equipped with high-speed camera were used to characterize the ballistic performance with the impact velocities ranging from 100 m/s to 450 m/*** results showed that the ballistic limits(V_(bl))of DFKF are approximately triple and double that of its counterpart UD and plain fabrics,*** mass-normalized metrics,the specific energy absorption(SEA)is 250%and 350%greater than the UD and plain fabrics at their corresponding V_(bl)*** quasi-static tests showed that the DFKF displayed greater resilience,crease recovery properties,and flexibility,which also made it an especially better candidate than UD and plain weaves for the design of umbrella surface *** was also found that DFKF is dependent on yarn count and the incorporation of spandex.A prototype anti-ballistic umbrella is manufactured using DFKF made of 200D multi-filament *** ballistic performance is also sensitive to the impact site when the umbrella is subjected to impact.
Aramid fibers,due to their relatively high inter-yarn friction,high strength,high modulus,and other characteristics,have become a typical representative of flexible anti-ballistic materials in modern *** research on t...
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Aramid fibers,due to their relatively high inter-yarn friction,high strength,high modulus,and other characteristics,have become a typical representative of flexible anti-ballistic materials in modern *** research on the anti-penetration of aramid fabrics mostly focuses unilaterally on the structure and performance of aramid fabrics or the shape and size of projectiles,with fewer studies on the coupled effect of both on ballistic *** study analyzes how the coupling relationship(or size effect)between the projectile and fiber bundle dimensions affects the fabric ballistic performance from a mesoscopic scale *** plain weave aramid fabric as the research object,considering different diameter projectiles,through a large number of ballistic impact tests and numerical simulations,parameters such as ballistic limit velocity,average energy absorption of fabric,and specific energy absorption ratio(average energy absorption of fabric divided by projectile cross-sectional area)are obtained for ballistic performance *** influence law of projectile size on the ballistic performance of high-performance fabrics is as follows:The relative range of fitted ballistic limit velocity at different target positions gradually decreases and then stabilizes as the projectile diameter increases,indicating that the fabric structure effect gradually disappears at a projectile diameter of 12 mm;The average ballistic limit velocity at three impact positions,P1,P2,and P3,provides the corresponding ballistic limit velocity for 1000D aramid fabric,which increases with projectile diameter but the rate of increase slows down at an inflection point,which in this study occurs where the fabric structure effect nearly disappears at a projectile diameter of 12 mm;The energy absorption ratio increases and then decreases as the projectile diameter increases from 4 mm to 20 mm,reaching a peak at the diameter of 12 mm due to the gradual disappearance of the fabri
Conversion-type anode materials are highly desirable for Na-ion batteries(NIBs)due to their high theoretical ***,the active materials undergo severe expansion and pulverization during the sodiation,resulting in inferi...
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Conversion-type anode materials are highly desirable for Na-ion batteries(NIBs)due to their high theoretical ***,the active materials undergo severe expansion and pulverization during the sodiation,resulting in inferior cycling ***,a self-supporting three-dimensional(3D)graphene sponge decorated with Fe_(2)O_(3)nanocubes(rGO@Fe_(2)O_(3))is ***,the 3D graphene sponge with resilience and high porosity benefits to accommodate the volume expansion of the Fe_(2)O_(3)nanocubes and facilitates the rapid electrons/ions transport,enabling spatial confinement to achieve outstanding ***,the free-standing rGO@Fe_(2)O_(3)can be directly used as an electrode without additional binders and conductive additives,which helps to obtain a higher energy *** on the total mass of the rGO@Fe_(2)O_(3)material,the rGO@Fe_(2)O_(3)anode presents a specific capacity of 859 mAh/g at 0.1 A/*** also delivers an impressive cycling performance(327 mAh/g after 2000 cycles at 1 A/g)and a superior rate capacity(162mAh/g at 20 A/g).The coin-type Na_(3)V_(2)(PO_(4))_(3)@C//rGO@Fe_(2)O_(3)NIB exhibits an energy density of 265.3Wh/*** unique 3D ionic/electronic conductive network may provide new strategies to design advanced conversion-type anode materials for high-performance NIBs.
作者:
Hu, GuangzhouLi, Min
State Key Laboratory of New Textile Materials and Advanced Processing Research Center for Intelligent Fiber Devices and Equipment Hubei Wuhan430074 China
This article presents a bio-inspired measurement model for the internal force and torque monitoring of human joints, which serves as the foundation of a robotic-assisted sit-to-stand (RA-STS) system consisting of an S...
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The exceptional photoelectric performance and high compatibility of perovskite materials render perovskite solar cells highly promising for extensive development,thus garnering significant *** perovskite solar cells,t...
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The exceptional photoelectric performance and high compatibility of perovskite materials render perovskite solar cells highly promising for extensive development,thus garnering significant *** perovskite solar cells,the hole transport layer plays a crucial *** the commonly employed organic small molecule hole transport material Spiro-OMeTAD,a certain period of oxidation treatment is required to achieve complete transport ***,this posttreatment oxidation processes typically rely on ambient oxidation,which poses challenges in terms of precise control and leads to degradation of the perovskite light absorption *** approach fails to meet the demands for high efficiency and stability in practical ***,the mechanism of ultrafast laser on Spiro-OMeTAD and the reaction process for laser-induced oxidation of it are ***2at Perovskite/Spiro-OMeTAD interface breaks down to produce I2upon ultrafast laser irradiation and I2promote the oxidation *** the laser irradiation oxidation processing,a higher stability of perovskite solar cells is *** work establishes a new approach toward oxidation treatment of Spiro-OMeTAD.
Electronics over flexible substrates offer advantages of flexibility, portability and low cost, and promising applications in the areas of energy, information, defense science and medical service. In recent years, tre...
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Electronics over flexible substrates offer advantages of flexibility, portability and low cost, and promising applications in the areas of energy, information, defense science and medical service. In recent years, tremendous progress has been witnessed in the development of flexible wearable devices that can be potentially massively deployed. Of particular interest are intelligent wearable devices, such as sensors and storage cells, which can be integrated by flexible magnetoelectronic devices based on magnetic thin films. To examine this further, the magnetic properties of FeNi thin films with different thicknesses grown on flexible graphene substrate are investigated at room temperature. The coercivity increases with increasing thicknesses of FeNi thin film, which can be attributed to the increase of grain size and decrease of surface roughness. Moreover, the thickness modulated magnetic property shows a magnetic anisotropy shift increase with varying thicknesses of FeNi thin film by using measurements based on ferromagnetic resonance, which further enhances the resonance frequency. In addition, the resonance peak is quite stable after bending it for ten cycles. The result is promising for the future design of flexible magnetoelectronic devices.
Porous ceramics are lightweight materials with diverse pore structures and are widely applied in areas such as thermal insulation, sound absorption, filtration, catalysis, and energy storage. However, excessive shrink...
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Porous ceramics are lightweight materials with diverse pore structures and are widely applied in areas such as thermal insulation, sound absorption, filtration, catalysis, and energy storage. However, excessive shrinkage during the sintering process of porous ceramics leads to cracking and deterioration, posing significant challenges for achieving complex shapes. Despite its importance, the field of low sintering shrinkage porous ceramics has not received sufficient attention. This review systematically discusses the principles and progress in the development of low sintering shrinkage porous ceramics. First, we introduce the characteristics of various preparation methods, including partial sintering, particle-stabilized foaming, gel-casting, foam-gelcasting, and additive manufacturing (AM). We then explain three primary principles of low sintering shrinkage from the perspectives of the volume effect and mass transfer processes. This review focuses on the properties and applications of typical low sintering shrinkage ceramics such as mullite and alumina, particularly their mechanical properties and thermal conductivity as thermal insulation and ceramic cores. Finally, we summarize the current state and present future perspectives on low sintering shrinkage porous ceramics.
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