In order to improve the comprehensive properties of the Cu-11.9Al-2.5Mn shape memory alloy(SMA),multilayer graphene(MLG)carried by Cu_(51)Zr_(14)inoculant particles was incorporated and dispersed into this alloy throu...In order to improve the comprehensive properties of the Cu-11.9Al-2.5Mn shape memory alloy(SMA),multilayer graphene(MLG)carried by Cu_(51)Zr_(14)inoculant particles was incorporated and dispersed into this alloy through preparing the preform of the cold-pressed MLG-Cu_(51)Zr_(14)composite powders.In the resultant novel MLG/Cu-Al-Mn composites,MLG in fragmented or flocculent form has a good bonding with the Cu-Al-Mn matrix.MLG can prevent the coarsening of grains of the Cu-Al-Mn SMA and cause thermal mismatch dislocations near the MLG/Cu-Al-Mn interfaces.The damping and mechanical properties of the MLG/Cu-Al-Mn composites are significantly improved.When the content of MLG reaches 0.2 wt.%,the highest room temperature damping of 0.0558,tensile strength of 801.5 MPa,elongation of 10.8%,and hardness of HV 308 can be obtained.On the basis of in-depth observation of microstructures,combined with the theory of internal friction and strengthening and toughening theories of metals,the relevant mechanisms are discussed.展开更多
A National Science Foundation of China （NSFC） major research project, Destruction of the North China Craton （NCC）, has been carried out in the past few years by Chinese scientists through an in-depth and systemati...A National Science Foundation of China （NSFC） major research project, Destruction of the North China Craton （NCC）, has been carried out in the past few years by Chinese scientists through an in-depth and systematic observations, experiments and theoretical analyses, with an emphasis on the spatio-temporal distribution of the NCC destruction, the structure of deep earth and shallow geological records of the craton evolution, the mechanism and dynamics of the craton destruction. From this work the foUowing conclusions can be drawn： （1） Significant spatial heterogeneity exists in the NCC lithospheric thickness and crustal structure, which constrains the scope of the NCC destruction. （2） The nature of the Paleozoic, Mesozoic and Cenozoic sub-continental lithospheric mantle （CLM） underneath the NCC is characterized in detail. In terms of water content, the late Mesozoic CLM was rich in water, but Cenozoic CLM was highly water deficient. （3） The correlation between magmatism and surface geological response confirms that the geological and tectonic evolution is governed by cratonic destruction processes. （4） Pacific subduction is the main dynamic factor that triggered the destruction of the NCC, which highlights the role of cratonic destruction in plate tectonics.展开更多
基金supported by the Natural Science Foundation of Hebei Province,China(No.E2021202017)the National Natural Science Foundation of China(No.52061038)+3 种基金the Foundation Strengthening Program,China(No.2019-JCJQ-ZD-142-00)the Hebei Province Graduate Innovation Funding Project,China(No.CXZZBS2022032)the Jiangsu Provincial Policy Guidance Program(Special Project for the Introduction of Foreign Talents)Talent Introduction Program,China(No.BX2021024)the Science Plan Foundation of Tianjin Municipal Education Commission,China(No.2021KJ026)。
文摘In order to improve the comprehensive properties of the Cu-11.9Al-2.5Mn shape memory alloy(SMA),multilayer graphene(MLG)carried by Cu_(51)Zr_(14)inoculant particles was incorporated and dispersed into this alloy through preparing the preform of the cold-pressed MLG-Cu_(51)Zr_(14)composite powders.In the resultant novel MLG/Cu-Al-Mn composites,MLG in fragmented or flocculent form has a good bonding with the Cu-Al-Mn matrix.MLG can prevent the coarsening of grains of the Cu-Al-Mn SMA and cause thermal mismatch dislocations near the MLG/Cu-Al-Mn interfaces.The damping and mechanical properties of the MLG/Cu-Al-Mn composites are significantly improved.When the content of MLG reaches 0.2 wt.%,the highest room temperature damping of 0.0558,tensile strength of 801.5 MPa,elongation of 10.8%,and hardness of HV 308 can be obtained.On the basis of in-depth observation of microstructures,combined with the theory of internal friction and strengthening and toughening theories of metals,the relevant mechanisms are discussed.
基金supported by National Natural Science Foundation of China (Grant Nos.90714001,90714004,90714008,90714009,91014006,91114206)
文摘A National Science Foundation of China （NSFC） major research project, Destruction of the North China Craton （NCC）, has been carried out in the past few years by Chinese scientists through an in-depth and systematic observations, experiments and theoretical analyses, with an emphasis on the spatio-temporal distribution of the NCC destruction, the structure of deep earth and shallow geological records of the craton evolution, the mechanism and dynamics of the craton destruction. From this work the foUowing conclusions can be drawn： （1） Significant spatial heterogeneity exists in the NCC lithospheric thickness and crustal structure, which constrains the scope of the NCC destruction. （2） The nature of the Paleozoic, Mesozoic and Cenozoic sub-continental lithospheric mantle （CLM） underneath the NCC is characterized in detail. In terms of water content, the late Mesozoic CLM was rich in water, but Cenozoic CLM was highly water deficient. （3） The correlation between magmatism and surface geological response confirms that the geological and tectonic evolution is governed by cratonic destruction processes. （4） Pacific subduction is the main dynamic factor that triggered the destruction of the NCC, which highlights the role of cratonic destruction in plate tectonics.
