作为一种新型被动减振技术,颗粒阻尼已被应用于船舶、航空等领域。为进一步研究颗粒阻尼耗能机理,提高其减振性能,基于离散元(Discrete Element Method,DEM)-多体动力学(Multi Body Dynamic,MBD)耦合方法建立弹簧-颗粒阻尼减振系统模型...作为一种新型被动减振技术,颗粒阻尼已被应用于船舶、航空等领域。为进一步研究颗粒阻尼耗能机理,提高其减振性能,基于离散元(Discrete Element Method,DEM)-多体动力学(Multi Body Dynamic,MBD)耦合方法建立弹簧-颗粒阻尼减振系统模型,研究颗粒填充率及颗粒半径对系统减振效果的影响,并分析其耗能特性;通过试验验证DEM-MBD耦合仿真方法的准确性,等效阻尼比仿真值与试验值的平均误差为11.8%。研究结果表明:通过选择合适的填充比,可使弹簧-颗粒阻尼减振系统最大等效阻尼比比无颗粒时提高12.9倍。研究结果可为后续颗粒阻尼减振设计提供一定参考。展开更多
Metal-organic frameworks(MOFs)are import-ant as possible energy storage materials.Nitrogen-doped iron-cobalt MOFs were synthesized by a one-pot solvo-thermal method using CoCl_(3)·6H_(2)O and FeCl_(3)·6H_(2)...Metal-organic frameworks(MOFs)are import-ant as possible energy storage materials.Nitrogen-doped iron-cobalt MOFs were synthesized by a one-pot solvo-thermal method using CoCl_(3)·6H_(2)O and FeCl_(3)·6H_(2)O dis-solved in N,N-dimethylformamide,and were converted into Fe-Co embedded in N-doped porous carbon polyhedra by pyrolysis in a nitrogen atmosphere.During pyrolysis,the or-ganic ligands transformed into N-doped porous carbon which improved their structural stability and also their electrical contact with other materials.The Fe and Co are tightly bound together because of their encapsulation by the carbon nitride and are well dispersed in the carbon matrix,and improve the material’s conductivity and stability and provide additional capacity.When used as the anode for lithium-ion batteries,the material gives an initial capacity of up to 2230.7 mAh g^(-1)and a reversible capa-city of 1146.3 mAh g^(-1)is retained after 500 cycles at a current density of 0.5 A g^(-1),making it an excellent candidate for this purpose.展开更多
文摘作为一种新型被动减振技术,颗粒阻尼已被应用于船舶、航空等领域。为进一步研究颗粒阻尼耗能机理,提高其减振性能,基于离散元(Discrete Element Method,DEM)-多体动力学(Multi Body Dynamic,MBD)耦合方法建立弹簧-颗粒阻尼减振系统模型,研究颗粒填充率及颗粒半径对系统减振效果的影响,并分析其耗能特性;通过试验验证DEM-MBD耦合仿真方法的准确性,等效阻尼比仿真值与试验值的平均误差为11.8%。研究结果表明:通过选择合适的填充比,可使弹簧-颗粒阻尼减振系统最大等效阻尼比比无颗粒时提高12.9倍。研究结果可为后续颗粒阻尼减振设计提供一定参考。
文摘Metal-organic frameworks(MOFs)are import-ant as possible energy storage materials.Nitrogen-doped iron-cobalt MOFs were synthesized by a one-pot solvo-thermal method using CoCl_(3)·6H_(2)O and FeCl_(3)·6H_(2)O dis-solved in N,N-dimethylformamide,and were converted into Fe-Co embedded in N-doped porous carbon polyhedra by pyrolysis in a nitrogen atmosphere.During pyrolysis,the or-ganic ligands transformed into N-doped porous carbon which improved their structural stability and also their electrical contact with other materials.The Fe and Co are tightly bound together because of their encapsulation by the carbon nitride and are well dispersed in the carbon matrix,and improve the material’s conductivity and stability and provide additional capacity.When used as the anode for lithium-ion batteries,the material gives an initial capacity of up to 2230.7 mAh g^(-1)and a reversible capa-city of 1146.3 mAh g^(-1)is retained after 500 cycles at a current density of 0.5 A g^(-1),making it an excellent candidate for this purpose.
