In this paper,the electromagnetic performance of variable flux memory(VFM)machines with series-magnetic-circuit is investigated and compared for different rotor topologies.Based on a V-type VFM machine,five topologies...In this paper,the electromagnetic performance of variable flux memory(VFM)machines with series-magnetic-circuit is investigated and compared for different rotor topologies.Based on a V-type VFM machine,five topologies with different interior permanent magnet(IPM)arrangements are evolved and optimized under same constrains.Based on two-dimensional(2-D)finite element(FE)method,their electromagnetic performance at magnetization and demagnetization states is evaluated.It reveals that the iron bridge and rotor lamination region between constant PM(CPM)and variable PM(VPM)play an important role in torque density and flux regulation(FR)capabilities.Besides,the global efficiency can be improved in VFM machines by adjusting magnetization state(MS)under different operating conditions.展开更多
The unidirectional excitation of near-field optical modes is a fundamental prerequisite for many photonic applications,such as wireless power transfer and information communications.We experimentally construct all-ele...The unidirectional excitation of near-field optical modes is a fundamental prerequisite for many photonic applications,such as wireless power transfer and information communications.We experimentally construct all-electric Huygens and spin metasources and demonstrate anomalous unidirectional excitation of high-k hyperbolic modes in two types of hyperbolic metasurfaces.We use a Huygens metasource to study the unidirectional excitation of hyperbolic bulk modes in a planar hyperbolic metamaterial(HMM).Specifically,unidirectional excitation is the same as that in free space in the vertical direction,but opposite to that in free space in the horizontal direction.This anomalous unidirectional excitation is determined by the anisotropic HMM dispersion.In addition,we use a spin metasource to observe the anomalous photonic spin Hall effect in a planar hyperbolic waveguide.For a near-field source with a specific spin,the guide mode with a fixed directional wave vector is excited due to spin-momentum locking.Because the directions of momentum and energy flows in the HMM waveguide are opposite,the unidirectional excitation of hyperbolic guided modes is reversed.Our results not only uncover the sophisticated electromagnetic functionalities of metasources in the near-field but may also provide novel opportunities for the development of integrated optical devices.展开更多
We construct an electrical circuit to realize a modified Haldane lattice exhibiting the phenomenon of antichiral edge states. The circuit consists of a network of inductors and capacitors with interconnections reprodu...We construct an electrical circuit to realize a modified Haldane lattice exhibiting the phenomenon of antichiral edge states. The circuit consists of a network of inductors and capacitors with interconnections reproducing the effects of a magnetic vector potential. The next nearest neighbor hoppings are configured differently from the standard Haldane model, and as predicted by earlier theoretical studies, this gives rise to antichiral edge states that propagate in the same direction on opposite edges and coexist with bulk states at the same frequency. Using pickup coils to measure voltage distributions in the circuit, we experimentally verify the key features of the antichiral edge states, including their group velocities and ability to propagate consistently in a M?bius strip configuration.展开更多
Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators.These systems ha...Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators.These systems have produced a series of applications,including optical isolators,delay lines,and lasers.However,the structures are complicated because an additional coupler ring between neighboring rings is needed to construct photonic pseudospin.A photonic anomalous Floquet topological insulator is proposed and experimentally demonstrated in the microwave regime.This improved design takes advantage of the efficient and backward coupling of negative-index media.The results contribute to the understanding of topological structures in metamaterials and point toward a unique direction for constructing useful topological photonic devices.展开更多
Here, we propose a simple scheme to realize a one-dimensional （1D） modulated Rice-Mele model （RMM） and investigate its topological properties with a 1D circuit quantum electrodynamics （QED） lattice. The system c...Here, we propose a simple scheme to realize a one-dimensional （1D） modulated Rice-Mele model （RMM） and investigate its topological properties with a 1D circuit quantum electrodynamics （QED） lattice. The system can be mapped into a Chern insulator model by introducing a period parameter. Interestingly and surprisingly, we found that the circuit-QED lattice system always exhibits topologically nonttrvial phases if both the nearest-neighbor hopping strength between two resonators and the qubitassisted on-site potentials are alternately changed in the direction of the lattice. The numerical results show that the topological phases can be obtained by introducing an additional modulation parameter and both the edge state and topological invariant can be unambiguously seen with the existence of decay and disorders, even with few resonators in the lattice.展开更多
在碰撞检测领域,对碰撞后样车进行必要修复可实现一辆样车完成多次碰撞试验,从而有效降低检测成本。将汽车电路修复与碰撞检测工作相结合,既拓展了车辆修复技术的应用空间,也为碰撞试验领域注入了新的动力。从实际碰撞标准出发提炼了碰...在碰撞检测领域,对碰撞后样车进行必要修复可实现一辆样车完成多次碰撞试验,从而有效降低检测成本。将汽车电路修复与碰撞检测工作相结合,既拓展了车辆修复技术的应用空间,也为碰撞试验领域注入了新的动力。从实际碰撞标准出发提炼了碰撞后车辆需要维修的典型功能,根据修复对象的特征对相关维修工作进行分类。以高压故障维修为重点方向详述了电路修复在碰撞检测领域的应用技术要点。针对高速碰撞后车辆损坏严重、通信网络易瘫痪的维修难点,提出一种外置网关法以避开事故车辆的故障通信网络,及时读取车辆事故信息和故障码。最后,结合CAN(controller area network,控制器局域网)总线拓扑图,精准维修并恢复必要CAN总线子系统的通信功能,实现碰撞后车辆的高效维修。展开更多
为了准确快速地分析大规模10 kV配电网设备短路电流水平,提出了一种基于地理信息系统(geographic information system,GIS)拓扑数据的配电网短路电流算法。该算法基于配电网GIS的设备拓扑数据及常规电网数据,将配电网10 kV设备简化成各...为了准确快速地分析大规模10 kV配电网设备短路电流水平,提出了一种基于地理信息系统(geographic information system,GIS)拓扑数据的配电网短路电流算法。该算法基于配电网GIS的设备拓扑数据及常规电网数据,将配电网10 kV设备简化成各个节点模型与支路模型,运用Excel的计算模块实现大规模配电网设备节点的短路电流水平计算。以东莞电网为例进行断路器短路电流仿真计算,结果表明该算法能够实现配电网大规模数据处理,快速计算设备短路电流。展开更多
基金supported by the CRRC Zhuzhou Institute Company Ltd.and in part by Key R&D projects in Hunan+1 种基金ChinaNo.2022GK2062。
文摘In this paper,the electromagnetic performance of variable flux memory(VFM)machines with series-magnetic-circuit is investigated and compared for different rotor topologies.Based on a V-type VFM machine,five topologies with different interior permanent magnet(IPM)arrangements are evolved and optimized under same constrains.Based on two-dimensional(2-D)finite element(FE)method,their electromagnetic performance at magnetization and demagnetization states is evaluated.It reveals that the iron bridge and rotor lamination region between constant PM(CPM)and variable PM(VPM)play an important role in torque density and flux regulation(FR)capabilities.Besides,the global efficiency can be improved in VFM machines by adjusting magnetization state(MS)under different operating conditions.
基金This work was supported by the National Key R&D Program of China(Grant No.2016YFA0301101)the National Natural Science Foundation of China(NSFC)(Grant Nos.12004284,11775159,61621001,and 11935010)+3 种基金the Natural Science Foundation of Shanghai(Grant Nos.18ZR1442800 and 18JC1410900)China Postdoctoral Science Foundation(Grant Nos.2019TQ0232 and 2019M661605)the Shanghai Super Postdoctoral Incentive Programand the Opening Project of Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology.The authors declare no conflicts of interest.
文摘The unidirectional excitation of near-field optical modes is a fundamental prerequisite for many photonic applications,such as wireless power transfer and information communications.We experimentally construct all-electric Huygens and spin metasources and demonstrate anomalous unidirectional excitation of high-k hyperbolic modes in two types of hyperbolic metasurfaces.We use a Huygens metasource to study the unidirectional excitation of hyperbolic bulk modes in a planar hyperbolic metamaterial(HMM).Specifically,unidirectional excitation is the same as that in free space in the vertical direction,but opposite to that in free space in the horizontal direction.This anomalous unidirectional excitation is determined by the anisotropic HMM dispersion.In addition,we use a spin metasource to observe the anomalous photonic spin Hall effect in a planar hyperbolic waveguide.For a near-field source with a specific spin,the guide mode with a fixed directional wave vector is excited due to spin-momentum locking.Because the directions of momentum and energy flows in the HMM waveguide are opposite,the unidirectional excitation of hyperbolic guided modes is reversed.Our results not only uncover the sophisticated electromagnetic functionalities of metasources in the near-field but may also provide novel opportunities for the development of integrated optical devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.11874274,and 12004425)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20170058,and BK20200630)+1 种基金a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)supported by the Singapore MOE Academic Research Fund Tier 3(Grant No.MOE2016-T3-1006)。
文摘We construct an electrical circuit to realize a modified Haldane lattice exhibiting the phenomenon of antichiral edge states. The circuit consists of a network of inductors and capacitors with interconnections reproducing the effects of a magnetic vector potential. The next nearest neighbor hoppings are configured differently from the standard Haldane model, and as predicted by earlier theoretical studies, this gives rise to antichiral edge states that propagate in the same direction on opposite edges and coexist with bulk states at the same frequency. Using pickup coils to measure voltage distributions in the circuit, we experimentally verify the key features of the antichiral edge states, including their group velocities and ability to propagate consistently in a M?bius strip configuration.
基金the financial support from the National Key R&D Program of China(Grant No.2021YFA1400602)the National Natural Science Foundation of China(Grant Nos.12004284,11974261,91850206,and 61621001)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.22120210579)the Shanghai Chenguang Plan(Grant No.21CGA22).
文摘Photonic and acoustic topological insulators exhibiting one-way transportation that is robust against defects and impurities are typically realized in coupled arrays of two-dimensional ring resonators.These systems have produced a series of applications,including optical isolators,delay lines,and lasers.However,the structures are complicated because an additional coupler ring between neighboring rings is needed to construct photonic pseudospin.A photonic anomalous Floquet topological insulator is proposed and experimentally demonstrated in the microwave regime.This improved design takes advantage of the efficient and backward coupling of negative-index media.The results contribute to the understanding of topological structures in metamaterials and point toward a unique direction for constructing useful topological photonic devices.
基金supported by the National Natural Science Foundation of China(Grant Nos.11465020,11264042,61465013,and 11564041)the Project of Jilin Science and Technology Development for Leading Talent of Science and Technology Innovation in Middle and Young and Team Project(Grant No.20160519022JH)
文摘Here, we propose a simple scheme to realize a one-dimensional （1D） modulated Rice-Mele model （RMM） and investigate its topological properties with a 1D circuit quantum electrodynamics （QED） lattice. The system can be mapped into a Chern insulator model by introducing a period parameter. Interestingly and surprisingly, we found that the circuit-QED lattice system always exhibits topologically nonttrvial phases if both the nearest-neighbor hopping strength between two resonators and the qubitassisted on-site potentials are alternately changed in the direction of the lattice. The numerical results show that the topological phases can be obtained by introducing an additional modulation parameter and both the edge state and topological invariant can be unambiguously seen with the existence of decay and disorders, even with few resonators in the lattice.
文摘在碰撞检测领域,对碰撞后样车进行必要修复可实现一辆样车完成多次碰撞试验,从而有效降低检测成本。将汽车电路修复与碰撞检测工作相结合,既拓展了车辆修复技术的应用空间,也为碰撞试验领域注入了新的动力。从实际碰撞标准出发提炼了碰撞后车辆需要维修的典型功能,根据修复对象的特征对相关维修工作进行分类。以高压故障维修为重点方向详述了电路修复在碰撞检测领域的应用技术要点。针对高速碰撞后车辆损坏严重、通信网络易瘫痪的维修难点,提出一种外置网关法以避开事故车辆的故障通信网络,及时读取车辆事故信息和故障码。最后,结合CAN(controller area network,控制器局域网)总线拓扑图,精准维修并恢复必要CAN总线子系统的通信功能,实现碰撞后车辆的高效维修。
文摘为了准确快速地分析大规模10 kV配电网设备短路电流水平,提出了一种基于地理信息系统(geographic information system,GIS)拓扑数据的配电网短路电流算法。该算法基于配电网GIS的设备拓扑数据及常规电网数据,将配电网10 kV设备简化成各个节点模型与支路模型,运用Excel的计算模块实现大规模配电网设备节点的短路电流水平计算。以东莞电网为例进行断路器短路电流仿真计算,结果表明该算法能够实现配电网大规模数据处理,快速计算设备短路电流。
