The advancement of bioceramics has led to the emergence of mesoporous bioactive glasses (MBGs) as important materials for bone implants, thanks to their high specific surface area and bioactivity. One remaining challe...
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To enhance the protective performance of ceramic composite armor,ballistic penetration experiments were conducted on Al_(2)O_(3) ceramic-ultra-high molecular weight polyethylene(UHMWPE)composite armor with different t...
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To enhance the protective performance of ceramic composite armor,ballistic penetration experiments were conducted on Al_(2)O_(3) ceramic-ultra-high molecular weight polyethylene(UHMWPE)composite armor with different thickness *** damage and failure modes of hard projectiles and ceramic-fiber composite targets were *** recovered projectiles and ceramic fragments were sieved and weighed at multiple stages,revealing a positive correlation between the degree of fragmentation of the projectiles and ceramics and the overall ballistic resistance of the composite *** simulations were performed using the LS-DYNA finite element software,and the simulation results showed high consistency with the experimental results,confirming the validity of the material *** results indicate that the projectile heads primarily exhibited crushing and abrasive *** projectile fragments mainly resulted from tensile and shear stress-induced *** failure modes of the composite targets included the formation of ceramic cones and radial cracks under high-velocity *** UHMWPE laminated plates exhibited interlayer separation caused by tensile waves,permanent plastic deformation of the rear surface bulging,and perforation failure primarily due to shear *** extended numerical simulations,while maintaining the same areal density and configuration of9 mm Al_(2)O_(3) ceramic+12 mm UHMWPE laminated composite armor,the thickness configurations of the Al_(2)O_(3) ceramic and UHMWPE laminated backplates were varied,and various thicknesses of UHMWPE laminates were simulated as the cover layer for the ceramic *** simulation results indicated that the composite armor configuration of 10 mm Al_(2)O_(3) ceramic+8 mm UHMWPE composite armor increased energy absorption by13.48%.When altering the cover layer thickness,a 4 mm UHMWPE+9 mm Al_(2)O_(3)+8 mm UHMWPE composite armor demonstrated a 27.11%improvement in energy abso
Solid oxide electrolytic cell(SOEC) is an energy conversion device that transfers electrical energy into chemical energy. It has garnered significant attention due to its high efficiency and thick current density. The...
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Solid oxide electrolytic cell(SOEC) is an energy conversion device that transfers electrical energy into chemical energy. It has garnered significant attention due to its high efficiency and thick current density. The oxygen evolution reaction(OER) and the hydrogen evolution reaction(HER) are two crucial half-reactions of SOEC, while both require excellent electrochemical performance under high-temperature and high-humidity ***, high catalytic activity and good stability of electrode materials are crucial for the practical application of SOEC. The perovskite structure of the oxygen electrodes has outstanding OER activity, while metal ceramic and metal oxide hydrogen electrodes possess good redox properties. This article firstly demonstrates the influence of the physical and electrochemical properties of electrode materials on the performance of SOEC, then illustrates the optimization strategies for electrode materials to improve electrolysis efficiency and extend service ***, the research priorities for the future development of electrode material are summarized.
A critical distance parameter is introduced to describe the stress gradient effect of notched metallic structures under random vibration loadings,which is the frequency domain expression of the theory of critical dist...
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A critical distance parameter is introduced to describe the stress gradient effect of notched metallic structures under random vibration loadings,which is the frequency domain expression of the theory of critical distance(TCD)based line method *** life estimation on notched metallic structures could be carried out by combining this parameter with the spectral method for random vibration fatigue life *** fatigue experiment under random vibration loadings is conducted on two types of notched plate specimens of 7075-T6 aviation-grade aluminum alloy,where both circumstances of large and small stress gradients in the notch region are *** correlation between the calculated results given by the proposed model and the experimental fatigue life results shows the satisfactory prediction capability on random vibration fatigue life for notch conditions of both steep and mild stress distribution variations.
Hastelloy is a nickel-chromium-molybdenum-iron-based alloy and a member of the ‘superalloy’ family. Hastelloy has exceptional properties like high strength, wear resistance and hightemperature stress-corrosion resis...
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Metal additive manufacturing(AM)technologies have made significant progress in the basic theoretical field since their invention in the ***,performance instability during continuous processing,such as thermal history,...
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Metal additive manufacturing(AM)technologies have made significant progress in the basic theoretical field since their invention in the ***,performance instability during continuous processing,such as thermal history,residual stress accumulation,and columnar grain epitaxial growth,consistently hinders their broad application in standardized industrial *** overcome these challenges,performance-control-oriented hybrid AM(HAM)technologies have been *** technologies,by leveraging external auxiliary processes,aim to regulate microstructural evolution and mechanical properties during metal *** paper provides a systematic and detailed review of performance-control-oriented HAM technology,which is categorized into two main groups:energy field-assisted AM(EFed AM,***,electromagnetic,and heat)technologies and interlayer plastic deformation-assisted AM(IPDed AM,*** shock peening,rolling,ultrasonic peening,and friction stir process)*** review covers the influence of external energy fields on the melting,flow,and solidification behavior of materials,and the regulatory effects of interlayer plastic deformation on grain refinement,nucleation,and ***,the role of performance-control-oriented HAM technologies in managing residual stress conversion,metallurgical defect closure,mechanical property improvement,and anisotropy regulation is thoroughly reviewed and *** review concludes with an analysis of future development trends in EFed AM and IPDed AM technologies.
Human beings are the most intelligent living beings on *** reconstructions of missing human limbs that can be naturally integrated into the human body is a lofty ambition and faces challenges in neuroscience,informati...
Human beings are the most intelligent living beings on *** reconstructions of missing human limbs that can be naturally integrated into the human body is a lofty ambition and faces challenges in neuroscience,information science,mechanical and electronic engineering,and many other *** on the development history of robotic prosthetic hands over the past 70 years,
In this study, modelling of specific wear rate and worn surface roughness of Al-WC nanocomposites is attempted. For fabrication of Al-WC nanocomposites, the liquid metallurgy-based ex situ method is exercised. A tailo...
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This research work explores the effects of dry, liquid N2-based cryogenic cooling and cryogenic plus MQL hybrid strategy on surface roughness, rake surface temperature, principal cutting-edge temperature, auxiliary cu...
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Autonomous navigation is a fundamental problem in *** methods generally build point cloud map or dense feature map in perceptual space;due to lack of cognition and memory formation mechanism,traditional methods exist ...
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Autonomous navigation is a fundamental problem in *** methods generally build point cloud map or dense feature map in perceptual space;due to lack of cognition and memory formation mechanism,traditional methods exist poor robustness and low cognitive *** a new navigation technology that draws inspiration from mammal’s navigation,bionic navigation method can map perceptual information into cognitive space,and have strong autonomy and environment *** improve the robot’s autonomous navigation ability,this paper proposes a cognitive map-based hierarchical navigation ***,the mammals’navigation-related grid cells and head direction cells are modeled to provide the robots with location *** then a global path planning strategy based on cognitive map is proposed,which can anticipate one preferred global path to the target with high efficiency and short ***,a hierarchical motion controlling method is proposed,with which the target navigation can be divided into several sub-target navigation,and the mobile robot can reach to these sub-targets with high confidence ***,some experiments are implemented,the results show that the proposed path planning method can avoid passing through obstacles and obtain one preferred global path to the target with high efficiency,and the time cost does not increase extremely with the increase of experience nodes *** motion controlling results show that the mobile robot can arrive at the target successfully only depending on its self-motion information,which is an effective attempt and reflects strong bionic properties.
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