Predictive PI (PPI) control form, capable of time delay compensation, has been put forward recently. This control algorithm is essentially a PI controller with enhanced derivative action, which is not only suitable fo...Predictive PI (PPI) control form, capable of time delay compensation, has been put forward recently. This control algorithm is essentially a PI controller with enhanced derivative action, which is not only suitable for long time delay process, but also of simple structure and excellent robust stability. The performance of PPI controller was demonstrated and compared with that of traditional PID controller by different tuning methods.展开更多
Precipitation strengthening is an effective approach to enhance the strength of soft magnetic alloys for applications at high temperatures,while inevitably results in deterioration in coercivity due to the pinning eff...Precipitation strengthening is an effective approach to enhance the strength of soft magnetic alloys for applications at high temperatures,while inevitably results in deterioration in coercivity due to the pinning effect on the domain wall movement.Here,we realize a good combination of high-temperature strength and ductility(ultimate tensile strength of 564 MPa and elongation of~20%,respectively)as well as low coercivity(6.97 Oe)of FeCo-2V-0.3Cr-0.2Mo soft magnetic alloy through introducing high-density magnetic nanoprecipitates.The magnetic nanoprecipitates are characterized by FeCo-based phase with disordered body-centered cubic structure,which enables the alloy to have a low coercivity.In addition,these nanoprecipitates can impede the dislocation motion and suppress the brittle fracture,which lead to a high tensile strength and ductility.This work provides a guideline to enhance strength and ductility while maintaining low coercivity in soft magnetic alloys via magnetic nanoprecipitates.展开更多
Lithium(Li)metal with high theoretical capacity and low electrochemical potential is the most ideal anode for next-generation high-energy batteries.However,the practical implementation of Li anode has been hindered by...Lithium(Li)metal with high theoretical capacity and low electrochemical potential is the most ideal anode for next-generation high-energy batteries.However,the practical implementation of Li anode has been hindered by dendritic growth and volume expansion during cycling,which results in low Coulombic efficiency(CE),short lifespan,and safety hazards.Here,we report a highly stable and dendrite-free Li metal anode by utilizing N-doped hollow porous bowl-like hard carbon/reduced graphene nanosheets(CB@rGO)hybrids as three-dimensional(3D)conductive and lithiophilic scaffold host.The lithiophilic carbon bowl(CB)mainly works as excellent guides during the Li plating process,whereas the rGO layer with high conductivity and mechanical stability maintains the integrity of the composite by confining the volume change in long-range order during cycling.Moreover,the local current density can be reduced due to the 3D conductive framework.Therefore,CB@rGO presents a low lithium metal nucleation overpotential of 18 mV,high CE of 98%,and stable cycling without obvious voltage fluctuation for over 600 cycles at a current density of 1 mA cm^(-2).Our study not only provides a good CB@rGO host and pre-Lithiated CB@rGO composite anode electrode,but also brings a new strategy of designing 3D electrodes for those active materials suffering from severe volume expansion.展开更多
基金"8 63" High-Tech Research &Development Program of China(No.2 0 0 1-AA413 13 0 )
文摘Predictive PI (PPI) control form, capable of time delay compensation, has been put forward recently. This control algorithm is essentially a PI controller with enhanced derivative action, which is not only suitable for long time delay process, but also of simple structure and excellent robust stability. The performance of PPI controller was demonstrated and compared with that of traditional PID controller by different tuning methods.
基金This work was supported financially by the Science Fund from Natural Science Foundation of Hebei Province(No.E2020202088)the Creative Research Groups(No.61271043)+1 种基金the National Natural Science Foundation of China(No.51771201 and 52002109)the Joint Research Fund Liaoning-Shenyang National Laboratory for Materials Science(No.20180510059)。
文摘Precipitation strengthening is an effective approach to enhance the strength of soft magnetic alloys for applications at high temperatures,while inevitably results in deterioration in coercivity due to the pinning effect on the domain wall movement.Here,we realize a good combination of high-temperature strength and ductility(ultimate tensile strength of 564 MPa and elongation of~20%,respectively)as well as low coercivity(6.97 Oe)of FeCo-2V-0.3Cr-0.2Mo soft magnetic alloy through introducing high-density magnetic nanoprecipitates.The magnetic nanoprecipitates are characterized by FeCo-based phase with disordered body-centered cubic structure,which enables the alloy to have a low coercivity.In addition,these nanoprecipitates can impede the dislocation motion and suppress the brittle fracture,which lead to a high tensile strength and ductility.This work provides a guideline to enhance strength and ductility while maintaining low coercivity in soft magnetic alloys via magnetic nanoprecipitates.
基金supported by the National Natural Science Foundation of China(Nos.52072323 and 51872098)the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen University,as well as Postdoctoral Foundation of China(2018M632929).
文摘Lithium(Li)metal with high theoretical capacity and low electrochemical potential is the most ideal anode for next-generation high-energy batteries.However,the practical implementation of Li anode has been hindered by dendritic growth and volume expansion during cycling,which results in low Coulombic efficiency(CE),short lifespan,and safety hazards.Here,we report a highly stable and dendrite-free Li metal anode by utilizing N-doped hollow porous bowl-like hard carbon/reduced graphene nanosheets(CB@rGO)hybrids as three-dimensional(3D)conductive and lithiophilic scaffold host.The lithiophilic carbon bowl(CB)mainly works as excellent guides during the Li plating process,whereas the rGO layer with high conductivity and mechanical stability maintains the integrity of the composite by confining the volume change in long-range order during cycling.Moreover,the local current density can be reduced due to the 3D conductive framework.Therefore,CB@rGO presents a low lithium metal nucleation overpotential of 18 mV,high CE of 98%,and stable cycling without obvious voltage fluctuation for over 600 cycles at a current density of 1 mA cm^(-2).Our study not only provides a good CB@rGO host and pre-Lithiated CB@rGO composite anode electrode,but also brings a new strategy of designing 3D electrodes for those active materials suffering from severe volume expansion.
