In a large area of the east—central Asian continent there is a unified seismic network system composed of two families of large—seismic belts that intersect conjugately. Such a seismic network in the middle—upper c...In a large area of the east—central Asian continent there is a unified seismic network system composed of two families of large—seismic belts that intersect conjugately. Such a seismic network in the middle—upper crust is actually a response to the plastic flow network in the lower lithosphere including the lower crust and lithospheric mantle. The existence of the unified plastic flow system confirms that the driving force for intraplate tectonic deformation results mainly from the compression of the India plate, while the long-range transmission of the force is carried out chiefly by means of plastic flow. The plastic flow network has a control over the intraplate tectonic deformation.展开更多
At room temperature,dry sliding wear tests were carried out using pin-on-disc test rig,in which the pin is made of vermicular iron and the disc is made of 40 Cr steel.The microstructures of the frictional surfaces for...At room temperature,dry sliding wear tests were carried out using pin-on-disc test rig,in which the pin is made of vermicular iron and the disc is made of 40 Cr steel.The microstructures of the frictional surfaces for the pin specimens were investigated.Under the action of both frictional heat and frictional shearing stress,aplastic deformation layer under the frictional surface is formed.The morphology and properties of the plastic deformation layer depend on specimen material,contact pressure and frictional shearing stress.In the plastic deformation layer,the phosphorous mass percent varies at different depth and results in different hardness.On the outer side of surface,the hardness is the biggest and the phosphorous mass percent is the highest.They become gradually small from outer side to inner side of the surface.展开更多
Novel properties and applications of multilayered nanowires(MNWs)urge researchers to understand their mechanical behaviors comprehensively.Using the molecular dynamic simulation,tensile behaviors of Ti/Ni MNWs are inv...Novel properties and applications of multilayered nanowires(MNWs)urge researchers to understand their mechanical behaviors comprehensively.Using the molecular dynamic simulation,tensile behaviors of Ti/Ni MNWs are investigated under a series of layer thickness values(1.31,2.34,and 7.17 nm)and strain rates(1.0×10^(8)s^(-1)≤ε≤5.0×10^(10)s^(-1)).The results demonstrate that deformation mechanisms of isopachous Ti/Ni MNWs are determined by the layer thickness and strain rate.Four distinct strain rate regions in the tensile process can be discovered,which are small,intermediate,critical,and large strain rate regions.As the strain rate increases,the initial plastic behaviors transform from interface shear(the shortest sample)and grain reorientation(the longest sample)in small strain rate region to amorphization of crystalline structures(all samples)in large strain rate region.Microstructure evolutions reveal that the disparate tensile behaviors are ascribed to the atomic fractions of different structures in small strain rate region,and only related to collapse of crystalline atoms in high strain rate region.A layer thickness-strain rate-dependent mechanism diagram is given to illustrate the couple effect on the plastic deformation mechanisms of the isopachous nanowires.The results also indicate that the modulation ratio significantly affects the tensile properties of unequal Ti/Ni MNWs,but barely affect the plastic deformation mechanisms of the materials.The observations from this work will promote theoretical researches and practical applications of Ti/Ni MNWs.展开更多
基金This project (No. 49070196) is funded by the National Science Foundation of China.
文摘In a large area of the east—central Asian continent there is a unified seismic network system composed of two families of large—seismic belts that intersect conjugately. Such a seismic network in the middle—upper crust is actually a response to the plastic flow network in the lower lithosphere including the lower crust and lithospheric mantle. The existence of the unified plastic flow system confirms that the driving force for intraplate tectonic deformation results mainly from the compression of the India plate, while the long-range transmission of the force is carried out chiefly by means of plastic flow. The plastic flow network has a control over the intraplate tectonic deformation.
基金Item Sponsored by Provincial Outstanding Youth Science Foundation of Henan in China(04120002100)Opening Foundationof State Key Laboratory of Solid Lubrication
文摘At room temperature,dry sliding wear tests were carried out using pin-on-disc test rig,in which the pin is made of vermicular iron and the disc is made of 40 Cr steel.The microstructures of the frictional surfaces for the pin specimens were investigated.Under the action of both frictional heat and frictional shearing stress,aplastic deformation layer under the frictional surface is formed.The morphology and properties of the plastic deformation layer depend on specimen material,contact pressure and frictional shearing stress.In the plastic deformation layer,the phosphorous mass percent varies at different depth and results in different hardness.On the outer side of surface,the hardness is the biggest and the phosphorous mass percent is the highest.They become gradually small from outer side to inner side of the surface.
基金Project supported by the National Natural Science Foundation of China(Grant No.11572259)the Natural Science Foundation of Shaanxi Province,China(Grant No.2019JQ-827)the Scientific Research Program Funded by Shaanxi Provincial Education Department,China(Grant No.19JK0672).
文摘Novel properties and applications of multilayered nanowires(MNWs)urge researchers to understand their mechanical behaviors comprehensively.Using the molecular dynamic simulation,tensile behaviors of Ti/Ni MNWs are investigated under a series of layer thickness values(1.31,2.34,and 7.17 nm)and strain rates(1.0×10^(8)s^(-1)≤ε≤5.0×10^(10)s^(-1)).The results demonstrate that deformation mechanisms of isopachous Ti/Ni MNWs are determined by the layer thickness and strain rate.Four distinct strain rate regions in the tensile process can be discovered,which are small,intermediate,critical,and large strain rate regions.As the strain rate increases,the initial plastic behaviors transform from interface shear(the shortest sample)and grain reorientation(the longest sample)in small strain rate region to amorphization of crystalline structures(all samples)in large strain rate region.Microstructure evolutions reveal that the disparate tensile behaviors are ascribed to the atomic fractions of different structures in small strain rate region,and only related to collapse of crystalline atoms in high strain rate region.A layer thickness-strain rate-dependent mechanism diagram is given to illustrate the couple effect on the plastic deformation mechanisms of the isopachous nanowires.The results also indicate that the modulation ratio significantly affects the tensile properties of unequal Ti/Ni MNWs,but barely affect the plastic deformation mechanisms of the materials.The observations from this work will promote theoretical researches and practical applications of Ti/Ni MNWs.
基金financially supported by the National Natural Science Foundation of China(Nos.52171117,52001161,51927801,51871111)JianHua Research Foundation of Hebei University of Technology,China(Nos.HB1921,HB1920)the Natural Science Foundation of Jiangsu Province,China(Nos.BK20200695,BK20202010)。
