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
In a recently published paper Metal-Like Gravity (MLG) and Its Cosmological Applications [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310035003000360034003200330030000000 , it was ...In a recently published paper Metal-Like Gravity (MLG) and Its Cosmological Applications [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310035003000360034003200330030000000 , it was determined that a new modification of Newtonian gravity could explain many of the cosmological mysteries such as the nature of dark matter and dark energy. The theory provided a gravitational physical system and explained the flatness of the galactic rotational curves (RC). A RC fit that was identical to MOND’s RC fit for spiral galaxies was generated with α as a fitting parameter determined as equal to 1.345. In this paper I am elaborating more on the theory’s cosmological extrapolation of MOND’s critical acceleration a0. This is done by further assessing the gravitational interaction between the galactic baryonic mass and the halo-DM mass in the star-galaxy overlapping volume estimated in MLG framework interpreting a0 as only a factor induced from the reduction of the galactic luminous mass. It is asserted that MOND and MLG dynamic equations are equivalent with MOND’s form, only expressing the equation with an intermediate solution by equating the magnitudes of δ (a parameter that defines a scaled surface galactic DM-density perpendicular to the galactic radial direction in the galaxy-star halo overlapping volume) and G.展开更多
The stiff and fragile structure of thermosetting polymers, such as epoxy, accomplices the innate cracks to cause fracture and therefore the applications of monolithic epoxy are not ubiquitous. However, it is well esta...The stiff and fragile structure of thermosetting polymers, such as epoxy, accomplices the innate cracks to cause fracture and therefore the applications of monolithic epoxy are not ubiquitous. However, it is well established that when reinforced especially by nano-fillers, its ability to withstand crack propagation is propitiously improved. The crack is either deflected or bifurcated when interacting with strong nano-filler such as Multi-Layer Graphene (MLG). Due to the deflection and bifurcation of cracks, specific fracture patterns are observed. Although these fracture patterns seem aesthetically appealing, however, if delved deeper, they can further be used to estimate the influence of nano-filler on the mechanical properties. Here we show that, by a meticulous examination of topographical features of fractured patterns, various important aspects related to fillers can be approximated such as dispersion state, interfacial interactions, presence of agglomerates, and overall influence of the incorporation of filler on the mechanical properties of nanocomposites.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.
文摘In a recently published paper Metal-Like Gravity (MLG) and Its Cosmological Applications [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310035003000360034003200330030000000 , it was determined that a new modification of Newtonian gravity could explain many of the cosmological mysteries such as the nature of dark matter and dark energy. The theory provided a gravitational physical system and explained the flatness of the galactic rotational curves (RC). A RC fit that was identical to MOND’s RC fit for spiral galaxies was generated with α as a fitting parameter determined as equal to 1.345. In this paper I am elaborating more on the theory’s cosmological extrapolation of MOND’s critical acceleration a0. This is done by further assessing the gravitational interaction between the galactic baryonic mass and the halo-DM mass in the star-galaxy overlapping volume estimated in MLG framework interpreting a0 as only a factor induced from the reduction of the galactic luminous mass. It is asserted that MOND and MLG dynamic equations are equivalent with MOND’s form, only expressing the equation with an intermediate solution by equating the magnitudes of δ (a parameter that defines a scaled surface galactic DM-density perpendicular to the galactic radial direction in the galaxy-star halo overlapping volume) and G.
文摘The stiff and fragile structure of thermosetting polymers, such as epoxy, accomplices the innate cracks to cause fracture and therefore the applications of monolithic epoxy are not ubiquitous. However, it is well established that when reinforced especially by nano-fillers, its ability to withstand crack propagation is propitiously improved. The crack is either deflected or bifurcated when interacting with strong nano-filler such as Multi-Layer Graphene (MLG). Due to the deflection and bifurcation of cracks, specific fracture patterns are observed. Although these fracture patterns seem aesthetically appealing, however, if delved deeper, they can further be used to estimate the influence of nano-filler on the mechanical properties. Here we show that, by a meticulous examination of topographical features of fractured patterns, various important aspects related to fillers can be approximated such as dispersion state, interfacial interactions, presence of agglomerates, and overall influence of the incorporation of filler on the mechanical properties of nanocomposites.
