Large-scale components of steel and aluminum alloys(Fe-Al)with high bonding strength are highly needed from space exploration to the fabrication of transportation systems.The formation of detrimental intermetallic com...Large-scale components of steel and aluminum alloys(Fe-Al)with high bonding strength are highly needed from space exploration to the fabrication of transportation systems.The formation of detrimental intermetallic compounds at the Al-Fe interface has limited the application range of the Fe-Al components.The modified friction stir additive manufacturing was developed for fabricating large-scale Fe-Al compo-nents with homogenously distributed interfacial amorphous layers rather than detrimental intermetallic compounds.The interfacial amorphous layers comprised an Mg-O rich amorphous layer<20 nm in thick-ness and an Al-Fe-Si amorphous layer<120 nm in thickness.The interfacial amorphous layers exhibited high thermal stability and did not change even after the post-processing heat treatment of heating at 500℃ for 20 min and aging at 170℃ for 7 h.The tensile strengths of the Fe-Al tensile specimens were increased from 160 to 250 MPa after the application of the post-processing heat treatment.The fracture occurred in the aluminum alloys instead of at the dissimilar metal interface,demonstrating that high bonding strength at the Al-Fe interface was enabled by the formation of homogenously distributed interfacial amorphous layers.展开更多
The objective of this research was to show a way to conduct rejuvenation of aged polymer modified asphalt binder（PMB） successfully.To fully evaluate and understand the rejuvenation of aged PMB,the Penetration grade ...The objective of this research was to show a way to conduct rejuvenation of aged polymer modified asphalt binder（PMB） successfully.To fully evaluate and understand the rejuvenation of aged PMB,the Penetration grade tests including penetration,soften point,ductility and elastic recovery and SuperpaveTM PG grade tests including DSR,BBR and DDT were conducted.The rejuvenation effect of aged PMB by utilizing a fluid recycling agent in common use for binder rejuvenation was evaluated.And then the compound rejuvenation effect of aged PMB by utilizing the recycling agent with a new modifying additive for binder modification was evaluated.The experimental results indicated that the recycling agent in common use currently does not apply to polymer modified asphalt binder rejuvenation.But the recycling agent together with the modifying additive can restore the characteristics of aged polymer modified binder very well.Therefore,compound rejuvenation of polymer modified asphalt binder is recommended.展开更多
Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the s...Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the surface acid-base properties of catalysts by introduction of alkali metal （Na, K） oxides inhibits the carbonization and as a result, improves the operational stability of these catalysts. An effect of promotion of nickel-alumina based composite doped by lanthanum oxide is found. This effect, caused by an additional route for the CO2 activation on Ni-La2O3/Al2O3/cordierite catalyst, is displayed in increase of methane conversion under conditions of an oxidant excess.展开更多
Attitude pursuit guidance law is suitable for low cost missiles.A strap-down seeker is used to achieve this guidance law.The additional angles of attack or sideslip caused by wind and by control system are considered ...Attitude pursuit guidance law is suitable for low cost missiles.A strap-down seeker is used to achieve this guidance law.The additional angles of attack or sideslip caused by wind and by control system are considered as two disturbing factors which make attitude pursuit law impossible.Therefore,general attitude pursuit guidance law did not account for this two disturbing factors,because with those disturbing factors,it is difficult to apply.To solve the problem,the principle of strap-down seeker detecting target is investigated,the mathematical control model is established,then a modified attitude pursuit guidance law which employs the angular correction for those two disturbing factors is presented.It is proved that the modified attitude pursuit guidance law is appropriated to both in the presence of the additional angle of attack or sideslip via the simulations with the mathematical control model and Monte-Carlo method.展开更多
基金supported by the National Natu-ral Science Foundation of China(Nos.52375396,52034005,and 51975553)the Liaoning Provincial Department of Science and Technology(No.2023JH2/101300149)+4 种基金the Shenyang Science and Technology Bureau(No.22-315-6-03)and Institute of Metal Re-search,Chinese Academy of Sciences(No.2023-ZD02-01)the Liaoning Province Excellent Youth Foundation(No.2021-YQ-01)the Program of the Youth Innovation Promotion Association of the Chi-nese Academy of Sciences(No.Y2021061)the Bintech-IMR R&D Program(No.GYY-JSBU-2022-002).
文摘Large-scale components of steel and aluminum alloys(Fe-Al)with high bonding strength are highly needed from space exploration to the fabrication of transportation systems.The formation of detrimental intermetallic compounds at the Al-Fe interface has limited the application range of the Fe-Al components.The modified friction stir additive manufacturing was developed for fabricating large-scale Fe-Al compo-nents with homogenously distributed interfacial amorphous layers rather than detrimental intermetallic compounds.The interfacial amorphous layers comprised an Mg-O rich amorphous layer<20 nm in thick-ness and an Al-Fe-Si amorphous layer<120 nm in thickness.The interfacial amorphous layers exhibited high thermal stability and did not change even after the post-processing heat treatment of heating at 500℃ for 20 min and aging at 170℃ for 7 h.The tensile strengths of the Fe-Al tensile specimens were increased from 160 to 250 MPa after the application of the post-processing heat treatment.The fracture occurred in the aluminum alloys instead of at the dissimilar metal interface,demonstrating that high bonding strength at the Al-Fe interface was enabled by the formation of homogenously distributed interfacial amorphous layers.
基金Funded in Part by the National Natural Science Foundation of China (No. 50878054)
文摘The objective of this research was to show a way to conduct rejuvenation of aged polymer modified asphalt binder（PMB） successfully.To fully evaluate and understand the rejuvenation of aged PMB,the Penetration grade tests including penetration,soften point,ductility and elastic recovery and SuperpaveTM PG grade tests including DSR,BBR and DDT were conducted.The rejuvenation effect of aged PMB by utilizing a fluid recycling agent in common use for binder rejuvenation was evaluated.And then the compound rejuvenation effect of aged PMB by utilizing the recycling agent with a new modifying additive for binder modification was evaluated.The experimental results indicated that the recycling agent in common use currently does not apply to polymer modified asphalt binder rejuvenation.But the recycling agent together with the modifying additive can restore the characteristics of aged polymer modified binder very well.Therefore,compound rejuvenation of polymer modified asphalt binder is recommended.
文摘Nickel-alumina catalysts supported on cordierite monoliths of honeycomb structure surpass essentially the conventional granulated ones with respect to the output in carbon dioxide reforming of methane. Adjusting the surface acid-base properties of catalysts by introduction of alkali metal （Na, K） oxides inhibits the carbonization and as a result, improves the operational stability of these catalysts. An effect of promotion of nickel-alumina based composite doped by lanthanum oxide is found. This effect, caused by an additional route for the CO2 activation on Ni-La2O3/Al2O3/cordierite catalyst, is displayed in increase of methane conversion under conditions of an oxidant excess.
文摘Attitude pursuit guidance law is suitable for low cost missiles.A strap-down seeker is used to achieve this guidance law.The additional angles of attack or sideslip caused by wind and by control system are considered as two disturbing factors which make attitude pursuit law impossible.Therefore,general attitude pursuit guidance law did not account for this two disturbing factors,because with those disturbing factors,it is difficult to apply.To solve the problem,the principle of strap-down seeker detecting target is investigated,the mathematical control model is established,then a modified attitude pursuit guidance law which employs the angular correction for those two disturbing factors is presented.It is proved that the modified attitude pursuit guidance law is appropriated to both in the presence of the additional angle of attack or sideslip via the simulations with the mathematical control model and Monte-Carlo method.
