The synthesized monoclinic（B-type） phase of Y2O3 has been investigated by in situ angle-dispersive x-ray diffraction in a diamond anvil cell up to 44 GPa at room temperature. A phase transition occurs from monoclini...The synthesized monoclinic（B-type） phase of Y2O3 has been investigated by in situ angle-dispersive x-ray diffraction in a diamond anvil cell up to 44 GPa at room temperature. A phase transition occurs from monoclinic（B-type） to hexagonal（A-type） phase at 23.5 GPa and these two phases coexist even at the highest pressure. Parameters of isothermal equation of state are V0= 69.0（1）A3, K0= 159（3） GPa, K0= 4（fixed） for the B-type phase and V0= 67.8（2） A3, K0= 156（3） GPa,K＇0= 4fixed for the A-type phase. The structural anisotropy increases with increasing pressure for both phases.展开更多
In recent years, integrated electricity-gas systems(IEGSs) have attracted widespread attention. The unifiedscheduling and control of the IEGS depends on high-precisionoperating data. To this end, it is necessary to es...In recent years, integrated electricity-gas systems(IEGSs) have attracted widespread attention. The unifiedscheduling and control of the IEGS depends on high-precisionoperating data. To this end, it is necessary to establish anappropriate state estimation (SE) model for IEGS to filter theraw measured data. Considering that power systems and naturalgas systems have different time scales and sampling periods, thispaper proposes a dynamic state estimation (DSE) method basedon a Kalman filter that can consider the dynamic characteristicsof natural gas pipelines. First, the standardized state transitionequations for the gas system are developed by applying the finitedifference method to the partial differential equations (PDEs) ofthe gas system;then the DSE model for IEGS is formulatedbased on a Kalman filter;also, the measurements from theelectricity system and the gas system with different samplingperiods are fused to ensure the observability of DSE by using theinterpolation method. The IEEE 39-bus electricity system and the18-nodes Belgium gas system are integrated as the test systems.Simulation results verify the proposed method’s accuracy andcalculation efficiency.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1232204 and 41502029)China Postdoctoral Science Foundation(Grant No.2015M580679)
文摘The synthesized monoclinic（B-type） phase of Y2O3 has been investigated by in situ angle-dispersive x-ray diffraction in a diamond anvil cell up to 44 GPa at room temperature. A phase transition occurs from monoclinic（B-type） to hexagonal（A-type） phase at 23.5 GPa and these two phases coexist even at the highest pressure. Parameters of isothermal equation of state are V0= 69.0（1）A3, K0= 159（3） GPa, K0= 4（fixed） for the B-type phase and V0= 67.8（2） A3, K0= 156（3） GPa,K＇0= 4fixed for the A-type phase. The structural anisotropy increases with increasing pressure for both phases.
基金This work was supported in part by National Natural Science Foundation of China(51777067)and(52077076)in part by funding from the State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources(LAPS2021-18).
文摘In recent years, integrated electricity-gas systems(IEGSs) have attracted widespread attention. The unifiedscheduling and control of the IEGS depends on high-precisionoperating data. To this end, it is necessary to establish anappropriate state estimation (SE) model for IEGS to filter theraw measured data. Considering that power systems and naturalgas systems have different time scales and sampling periods, thispaper proposes a dynamic state estimation (DSE) method basedon a Kalman filter that can consider the dynamic characteristicsof natural gas pipelines. First, the standardized state transitionequations for the gas system are developed by applying the finitedifference method to the partial differential equations (PDEs) ofthe gas system;then the DSE model for IEGS is formulatedbased on a Kalman filter;also, the measurements from theelectricity system and the gas system with different samplingperiods are fused to ensure the observability of DSE by using theinterpolation method. The IEEE 39-bus electricity system and the18-nodes Belgium gas system are integrated as the test systems.Simulation results verify the proposed method’s accuracy andcalculation efficiency.
