Due to the phenomenon of abandoning wind power and photo voltage(PV)power in the“Three Northern Areas”in China,this paper presents an optimal strategy for coordinating and dispatching“source-load”in power system b...Due to the phenomenon of abandoning wind power and photo voltage(PV)power in the“Three Northern Areas”in China,this paper presents an optimal strategy for coordinating and dispatching“source-load”in power system based on multiple time scales.On the basis of the analysis of the uncertainty of wind power and PV power as well as the characteristics of load side resource dispatching,the optimal model of coordinating and dispatching“source-load”in power system based on multiple time scales is established.It can simultaneously and effectively dispatch conventional generators,wind plant,PV power station,pumped-storage power station and load side resources by optimally using three time scales:day-ahead,intra-day and real-time.According to the latest predicted information of wind power,PV power and load,the original generation schedule can be rolled and amended by using the corresponding time scale.The effectiveness of the model can be verified by a real system.The simulation results show that the proposed model can make full use of“source-load”resources to improve the ability to consume wind power and PV power of the grid-connected system.展开更多
New thermotropic chloro-bridged dinuclear palladium coordinating imine side chain liquid crystalline polysiloxanes have been synthesized. Their mesomorphic properties have been investigated by DSC, X-ray diffraction a...New thermotropic chloro-bridged dinuclear palladium coordinating imine side chain liquid crystalline polysiloxanes have been synthesized. Their mesomorphic properties have been investigated by DSC, X-ray diffraction and polarizing microscopy. The polymeric complexes show nematicdiscotic (Nd) mesophase. It is found that the temperature range of liquid crystalline state of chloro- bridged polymeric complexes is much wider than that of acetato- bridged ones and imine side chain polysiloxane. This indicates that the disc-like chloro-bridged palladium complexing units play a role as mesogen in mesophase.展开更多
The structures and energies of the side-on complexes B2（N2）2 and monocyclic Bn（N2）nm （n = 3～6,m = -1～＋2） between N2 （1∑＋g） and B （2P） have been investigated by the DFT-B3LYP and MP2 methods at the 6-311...The structures and energies of the side-on complexes B2（N2）2 and monocyclic Bn（N2）nm （n = 3～6,m = -1～＋2） between N2 （1∑＋g） and B （2P） have been investigated by the DFT-B3LYP and MP2 methods at the 6-311＋G（2d） and aug-cc-pVTZ levels. The analyses of NICS （Nucleus Independent Chemical Shifts）,NBO （nature bond orbital）,AIM （atoms in molecules） and frontal orbitals have been used to reveal the origin of coordination bond between the π-electron donor N2 group and B atom,accompanied by the comparison with the end-on complexes. The results have indicated that the side-on coordination complexes can be formed due to the relative strong fluidity of the π-electrons,and the nature of the coordination bond has been exposed to be that the N2 group offers 1πu electron to the 2p orbital of boron. The coordinate energies of the side-on complexes are less than those of the end-on complexes. Furthermore,the aromaticity of side-on coordination complex is weaker than that of the corresponding end-on coordination complex.展开更多
可再生能源和负荷的波动性、不确定性等给综合能源系统(integrated energy system,IES)的安全灵活运行带来了极大挑战。为提高IES灵活调节能力与可再生能源消纳水平,提出一种计及灵活性资源的IES源荷协调优化调度方法。针对系统内运行...可再生能源和负荷的波动性、不确定性等给综合能源系统(integrated energy system,IES)的安全灵活运行带来了极大挑战。为提高IES灵活调节能力与可再生能源消纳水平,提出一种计及灵活性资源的IES源荷协调优化调度方法。针对系统内运行灵活性需求,精细刻画各类资源灵活性能力,源侧根据电氢耦合单元运行特性构建热电联产机组(combined heating and power,CHP)和氢燃料电池(hydrogen fuel cell,HFC)联合运行模型,荷侧考虑综合需求响应的灵活性供给能力,建立系统综合灵活性供给模型。根据不同时刻运行灵活性不足问题分成2种调度模式,构建基于IES灵活性约束的优化调度模型,并进行仿真分析。仿真结果表明,所提出的优化调度方法能够有效提高IES灵活调节能力和可再生能源消纳水平。展开更多
水下目标物的准确识别是保障通航安全的一项重要工作,针对现有算法对水下多类别目标存在识别精度不高的问题,本文在YOLOv5s(You Only Look Once v5s)的基础上提出对其进行改进。首先,为平衡样本间的数量,通过利用几何变化操作模拟现实...水下目标物的准确识别是保障通航安全的一项重要工作,针对现有算法对水下多类别目标存在识别精度不高的问题,本文在YOLOv5s(You Only Look Once v5s)的基础上提出对其进行改进。首先,为平衡样本间的数量,通过利用几何变化操作模拟现实发生的情况对数量较少的样本进行扩充;其次,将YOLOv5s中传统损失函数CIoU惩罚项中的反正切函数改为Sigmoid函数,加快目标识别模型的收敛速度;最后,融合坐标注意力机制(Coordinate Attention,CA),融合后的模型能衡量每个通道信息的重要性,在关注目标位置信息的同时也不增加过多的计算量。试验结果表明:本文所提出的改进的YOLOv5s较改进前在准确率上提升了4.97%,在召回率上提高了6.20%,在类平均精度上提升了4.98%,证明本文改进的方法在工程应用上的价值。展开更多
基金Major Projects of Gansu Province(No.17ZD2GA010)Power Company Technology Projects of State Grid Corporation in Gansu Province(No.52272716000K)
文摘Due to the phenomenon of abandoning wind power and photo voltage(PV)power in the“Three Northern Areas”in China,this paper presents an optimal strategy for coordinating and dispatching“source-load”in power system based on multiple time scales.On the basis of the analysis of the uncertainty of wind power and PV power as well as the characteristics of load side resource dispatching,the optimal model of coordinating and dispatching“source-load”in power system based on multiple time scales is established.It can simultaneously and effectively dispatch conventional generators,wind plant,PV power station,pumped-storage power station and load side resources by optimally using three time scales:day-ahead,intra-day and real-time.According to the latest predicted information of wind power,PV power and load,the original generation schedule can be rolled and amended by using the corresponding time scale.The effectiveness of the model can be verified by a real system.The simulation results show that the proposed model can make full use of“source-load”resources to improve the ability to consume wind power and PV power of the grid-connected system.
文摘New thermotropic chloro-bridged dinuclear palladium coordinating imine side chain liquid crystalline polysiloxanes have been synthesized. Their mesomorphic properties have been investigated by DSC, X-ray diffraction and polarizing microscopy. The polymeric complexes show nematicdiscotic (Nd) mesophase. It is found that the temperature range of liquid crystalline state of chloro- bridged polymeric complexes is much wider than that of acetato- bridged ones and imine side chain polysiloxane. This indicates that the disc-like chloro-bridged palladium complexing units play a role as mesogen in mesophase.
文摘The structures and energies of the side-on complexes B2（N2）2 and monocyclic Bn（N2）nm （n = 3～6,m = -1～＋2） between N2 （1∑＋g） and B （2P） have been investigated by the DFT-B3LYP and MP2 methods at the 6-311＋G（2d） and aug-cc-pVTZ levels. The analyses of NICS （Nucleus Independent Chemical Shifts）,NBO （nature bond orbital）,AIM （atoms in molecules） and frontal orbitals have been used to reveal the origin of coordination bond between the π-electron donor N2 group and B atom,accompanied by the comparison with the end-on complexes. The results have indicated that the side-on coordination complexes can be formed due to the relative strong fluidity of the π-electrons,and the nature of the coordination bond has been exposed to be that the N2 group offers 1πu electron to the 2p orbital of boron. The coordinate energies of the side-on complexes are less than those of the end-on complexes. Furthermore,the aromaticity of side-on coordination complex is weaker than that of the corresponding end-on coordination complex.
文摘可再生能源和负荷的波动性、不确定性等给综合能源系统(integrated energy system,IES)的安全灵活运行带来了极大挑战。为提高IES灵活调节能力与可再生能源消纳水平,提出一种计及灵活性资源的IES源荷协调优化调度方法。针对系统内运行灵活性需求,精细刻画各类资源灵活性能力,源侧根据电氢耦合单元运行特性构建热电联产机组(combined heating and power,CHP)和氢燃料电池(hydrogen fuel cell,HFC)联合运行模型,荷侧考虑综合需求响应的灵活性供给能力,建立系统综合灵活性供给模型。根据不同时刻运行灵活性不足问题分成2种调度模式,构建基于IES灵活性约束的优化调度模型,并进行仿真分析。仿真结果表明,所提出的优化调度方法能够有效提高IES灵活调节能力和可再生能源消纳水平。
文摘水下目标物的准确识别是保障通航安全的一项重要工作,针对现有算法对水下多类别目标存在识别精度不高的问题,本文在YOLOv5s(You Only Look Once v5s)的基础上提出对其进行改进。首先,为平衡样本间的数量,通过利用几何变化操作模拟现实发生的情况对数量较少的样本进行扩充;其次,将YOLOv5s中传统损失函数CIoU惩罚项中的反正切函数改为Sigmoid函数,加快目标识别模型的收敛速度;最后,融合坐标注意力机制(Coordinate Attention,CA),融合后的模型能衡量每个通道信息的重要性,在关注目标位置信息的同时也不增加过多的计算量。试验结果表明:本文所提出的改进的YOLOv5s较改进前在准确率上提升了4.97%,在召回率上提高了6.20%,在类平均精度上提升了4.98%,证明本文改进的方法在工程应用上的价值。
