Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines pla...Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.展开更多
To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyur...To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyurea coating).The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests.The reliability of the numerical simulation using LS-DYNA software was verified by the test results.The effects of different scaled distances,reinforcement ratios,concrete strengths,coating thicknesses and ranges of polyurea were studied.The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder.The top plate of middle chamber in specimen G forms an elliptical penetrating hole,while that in specimen PCG only shows a very slight local dent.The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%,respectively,compared with those of specimen G.For the TNT explosion with small equivalent,the polyurea coating has a more significant protective effect on reducing the size of fracture.With the increase of TNT equivalent,the protective effect of polyurea on reducing girder displacement becomes more significant.The optimal reinforcement ratio,concrete strength,thickness and range of polyurea coating were also drawn.展开更多
金属材料挤出成型(metal material extrusion, MME)是采用金属粉末与聚合物黏结剂混合丝材为原料,通过成型、脱脂和烧结工艺(shaping-debinding-sintering, S-D-S)制造纯金属零部件的一种增材制造技术。随着MME技术的发展,亟须对其制品...金属材料挤出成型(metal material extrusion, MME)是采用金属粉末与聚合物黏结剂混合丝材为原料,通过成型、脱脂和烧结工艺(shaping-debinding-sintering, S-D-S)制造纯金属零部件的一种增材制造技术。随着MME技术的发展,亟须对其制品的抗冲击性能进行研究,然而相关信息非常匮乏。制备了不同过程参数下的MME试件,并采用夏比摆锤冲击试验研究了其抗冲击性能,探讨了成型方向、填充角度、挤出温度、床温及成型速度等过程参数对试件冲击吸收功的影响。结果表明:当填充角度为45°时,侧置方向成型试件的抗冲击性能最佳,水平方向次之,竖直方向最差;而在0°填充角度下,水平方向成型试件性能最好;进一步提高挤出温度、床温并降低成型速度,可以显著增强试件的抗冲击性能。研究结果为优化MME成型参数提供了理论依据,拓展了其在承受冲击载荷场景下的应用潜力。展开更多
The impact properties of normal concrete (NC) and reinforced concrete (RC) specimens,steel fibre reinforced concrete (SFRC) specimens and RC+SFRC specimens with different steel fibre dosages were investigated with the...The impact properties of normal concrete (NC) and reinforced concrete (RC) specimens,steel fibre reinforced concrete (SFRC) specimens and RC+SFRC specimens with different steel fibre dosages were investigated with the drop-weight impact test recommended by ACI Committee 544.The results indicate that the number of blows to final failure is greatly increased by addition of steel fibres.Moreover,the combination of steel fibres and steel rebars demonstrates a significant positive composite effect on the impact resistance,which results in the improvement in impact toughness of concrete specimens.In the view of variation of impact test results,the two-parameter Weibull distribution was adopted to analyze the experimental data.It is proved that the probabilistic distributions of the blows to first crack and to final failure of six types of samples approximately follow two-parameter Weibull distribution.展开更多
Fe-6.5Si soft magnetic composites(SMCs)with hybrid phosphate-silica insulation coatings have been designed to improve their comprehensive property via chemical coating combining sol-gel method in this work.The microst...Fe-6.5Si soft magnetic composites(SMCs)with hybrid phosphate-silica insulation coatings have been designed to improve their comprehensive property via chemical coating combining sol-gel method in this work.The microstructure and magnetic performance of the Fe-6.5Si SMCs with hybrid phosphate-silica insulation coatings were investigated.The hybrid phosphate-silica coatings with high heat resistance and high withstand pressure,formed on the surface of the Fe-6.5Si ferromagnetic powders,were found stable in the composites.Compared with Fe-6.5Si SMCs coated by single phosphate or single silica,Fe-6.5Si SMCs with hybrid phosphate-silica show much higher permeability and lower core loss.The work provides a new way to optimize the magnetic performance of soft magnetic composites.展开更多
文摘Because of an unfortunate mistake by authors,the Project(5227010679)of Foundation item was wrong.The corrected Project is shown as follows:Project(52271073).
基金Projects(42106051,42006046,U2106206) supported by the National Natural Science Foundation of ChinaProject(22373501D) supported by Hebei Provincial Key R&D Program,China。
文摘Copper is a versatile material,commonly utilized in power transmission and electronic devices,but its relative high reactivity necessitates a long-lasting protective technique.Here,we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition(PEUMS-PVD)and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO_(2)nanotubes/Ti_(3)AlC_(2)coating on the surface of Cu substrates.This novel strategy enhances the corrosion resistance of copper substrates in marine environments,with corrosion current densities of up to 4.5643×10^(−8)A/cm^(2).Among them,the doping of nano-aluminum particles makes the coating self-healing.The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise,and revealed that during the initial stages of coating immersion,uniform corrosion predominates,with a minor occurrence of localized corrosion.
基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20200494)China Postdoctoral Science Foundation(Grant No.2021M701725)+3 种基金Jiangsu Postdoctoral Research Funding Program(Grant No.2021K522C)Fundamental Research Funds for the Central Universities(Grant No.30919011246)National Natural Science Foundation of China(Grant No.52278188)Natural Science Foundation of Jiangsu Province(Grant No.BK20211196)。
文摘To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyurea coating).The failure characteristics and dynamic responses of the specimens were compared through conducting explosion tests.The reliability of the numerical simulation using LS-DYNA software was verified by the test results.The effects of different scaled distances,reinforcement ratios,concrete strengths,coating thicknesses and ranges of polyurea were studied.The results show that the polyurea coating can effectively enhance the anti-explosion performance of the girder.The top plate of middle chamber in specimen G forms an elliptical penetrating hole,while that in specimen PCG only shows a very slight local dent.The peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%,respectively,compared with those of specimen G.For the TNT explosion with small equivalent,the polyurea coating has a more significant protective effect on reducing the size of fracture.With the increase of TNT equivalent,the protective effect of polyurea on reducing girder displacement becomes more significant.The optimal reinforcement ratio,concrete strength,thickness and range of polyurea coating were also drawn.
文摘金属材料挤出成型(metal material extrusion, MME)是采用金属粉末与聚合物黏结剂混合丝材为原料,通过成型、脱脂和烧结工艺(shaping-debinding-sintering, S-D-S)制造纯金属零部件的一种增材制造技术。随着MME技术的发展,亟须对其制品的抗冲击性能进行研究,然而相关信息非常匮乏。制备了不同过程参数下的MME试件,并采用夏比摆锤冲击试验研究了其抗冲击性能,探讨了成型方向、填充角度、挤出温度、床温及成型速度等过程参数对试件冲击吸收功的影响。结果表明:当填充角度为45°时,侧置方向成型试件的抗冲击性能最佳,水平方向次之,竖直方向最差;而在0°填充角度下,水平方向成型试件性能最好;进一步提高挤出温度、床温并降低成型速度,可以显著增强试件的抗冲击性能。研究结果为优化MME成型参数提供了理论依据,拓展了其在承受冲击载荷场景下的应用潜力。
基金Project(50578026) supported by the National Natural Science Foundation of ChinaProject supported by FCT (SFRH/BPD/22680/2005)and Research Center of Mathematics of the University of Minho through the FCT Pluriannual Funding Program
文摘The impact properties of normal concrete (NC) and reinforced concrete (RC) specimens,steel fibre reinforced concrete (SFRC) specimens and RC+SFRC specimens with different steel fibre dosages were investigated with the drop-weight impact test recommended by ACI Committee 544.The results indicate that the number of blows to final failure is greatly increased by addition of steel fibres.Moreover,the combination of steel fibres and steel rebars demonstrates a significant positive composite effect on the impact resistance,which results in the improvement in impact toughness of concrete specimens.In the view of variation of impact test results,the two-parameter Weibull distribution was adopted to analyze the experimental data.It is proved that the probabilistic distributions of the blows to first crack and to final failure of six types of samples approximately follow two-parameter Weibull distribution.
基金Projects(2020GDSYL-20200402008,2018GDASCX-0117)supported by GDAS’Project of Science and Technology Development,ChinaProjects(2015B010136004,2019A1515010886)supported by Science and Technology Planning Project of Guangdong Province of ChinaProject(1920001001392)supported by Key Technology Project of Foshan,China。
文摘Fe-6.5Si soft magnetic composites(SMCs)with hybrid phosphate-silica insulation coatings have been designed to improve their comprehensive property via chemical coating combining sol-gel method in this work.The microstructure and magnetic performance of the Fe-6.5Si SMCs with hybrid phosphate-silica insulation coatings were investigated.The hybrid phosphate-silica coatings with high heat resistance and high withstand pressure,formed on the surface of the Fe-6.5Si ferromagnetic powders,were found stable in the composites.Compared with Fe-6.5Si SMCs coated by single phosphate or single silica,Fe-6.5Si SMCs with hybrid phosphate-silica show much higher permeability and lower core loss.The work provides a new way to optimize the magnetic performance of soft magnetic composites.
