This paper presents three compact ultra-wideband(UWB)antennas fed by coplanar waveguide(CPW).The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the feed line.Sim...This paper presents three compact ultra-wideband(UWB)antennas fed by coplanar waveguide(CPW).The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the feed line.Simulation by Ansoft high frequency structure simulator(HFSS)10.0 shows that the in-band impedances are quite stable and satisfactory.Rejected narrow frequency bands are further obtained within the wideband width by inserting U-shaped slots into the fed line of the antennas.The antennas have a dimension of 50mm by 40mm by 1.5mm.The simulation and measurement results show that the proposed antennas have stable directional radiation patterns,very low profile and low fabrication cost,which are suitable for the UWB system.展开更多
The excitation system of the homopolar inductor machine(HIM)is analyzed and designed to establish the design approach and evaluation criteria of the excitation system.The finite element method is used to calculate the...The excitation system of the homopolar inductor machine(HIM)is analyzed and designed to establish the design approach and evaluation criteria of the excitation system.The finite element method is used to calculate the three-dimensional electromagnetic field in the HIM,and the distribution and characteristics of the magnetic field are described.The analytical method is applied to investigate the design process of the excitation winding.The ratio of the axial length of the armature winding to the excitation winding and the ratio of the axial length of the working air-gap to the non-working air-gap are investigated by the numerical calculation method.A prototype HIM is designed and manufactured,and some experiments are implemented to verify the correctness of the theoretical analysis and numerical calculation results.The research results show that the established design method of the excitation winding is practical and feasible.Under the conditions of constant excitation magnetomotive force or constant excitation power,the optimum range of the axial length ratio of the armature winding and the excitation winding is 0.45 to 0.5.The optimal axial length of the non-working air-gap can be determined by the ratio of the stator inner diameter and pole-pairs.展开更多
In this paper, by making use of Duan＇s topological current theory, the branch process of regular magnetic monopoles is discussed in detail. Regular magnetic monopoles are found generating or annihilating at the limit...In this paper, by making use of Duan＇s topological current theory, the branch process of regular magnetic monopoles is discussed in detail. Regular magnetic monopoles are found generating or annihilating at the limit point and encountering, splitting, or merging at the bifurcation point and the degenerate point systematically of the vector order parameter field φ（x）. Furthermore, it is also shown that when regular magnetic monopoles split or merge at the degenerate point of field function φ, the total topological charges of the regular magnetic monopoles are stilI unchanged.展开更多
In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles o...In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles on different Riemann sheets axis when Nc = ∞＂. In this paper, we extend our previous work [Commun. Theor. to the ππ-KK=ηη three channel system. We reconfirm most of the predictions in our Phys., [arxiv：hep-ph/11081451]]. Especially the fo（980） is of KK molecule nature. 0 Breit-WJgner type. we proposed a method to distinThat is based on the observation which meet each other on the real phys,[arXiv：hep,ph/11081451]]pres.ious work ： Theor. ther poles, including the σ,are of Breit-wigner type.展开更多
基金Supported by the National High Technology Research and Development Programme of China(No.2007AA01Z261,2009AA01Z228)the National Science and Technology Major Special Project(No.2009ZX03007-001-01)
文摘This paper presents three compact ultra-wideband(UWB)antennas fed by coplanar waveguide(CPW).The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the feed line.Simulation by Ansoft high frequency structure simulator(HFSS)10.0 shows that the in-band impedances are quite stable and satisfactory.Rejected narrow frequency bands are further obtained within the wideband width by inserting U-shaped slots into the fed line of the antennas.The antennas have a dimension of 50mm by 40mm by 1.5mm.The simulation and measurement results show that the proposed antennas have stable directional radiation patterns,very low profile and low fabrication cost,which are suitable for the UWB system.
基金The National Natural Science Foundation of China(No.51977035)。
文摘The excitation system of the homopolar inductor machine(HIM)is analyzed and designed to establish the design approach and evaluation criteria of the excitation system.The finite element method is used to calculate the three-dimensional electromagnetic field in the HIM,and the distribution and characteristics of the magnetic field are described.The analytical method is applied to investigate the design process of the excitation winding.The ratio of the axial length of the armature winding to the excitation winding and the ratio of the axial length of the working air-gap to the non-working air-gap are investigated by the numerical calculation method.A prototype HIM is designed and manufactured,and some experiments are implemented to verify the correctness of the theoretical analysis and numerical calculation results.The research results show that the established design method of the excitation winding is practical and feasible.Under the conditions of constant excitation magnetomotive force or constant excitation power,the optimum range of the axial length ratio of the armature winding and the excitation winding is 0.45 to 0.5.The optimal axial length of the non-working air-gap can be determined by the ratio of the stator inner diameter and pole-pairs.
基金supported by National Natural Science Foundation of Chinathe Cuiying Programm of Lanzhou University
文摘In this paper, by making use of Duan＇s topological current theory, the branch process of regular magnetic monopoles is discussed in detail. Regular magnetic monopoles are found generating or annihilating at the limit point and encountering, splitting, or merging at the bifurcation point and the degenerate point systematically of the vector order parameter field φ（x）. Furthermore, it is also shown that when regular magnetic monopoles split or merge at the degenerate point of field function φ, the total topological charges of the regular magnetic monopoles are stilI unchanged.
基金Supported in part by National Nature Science Foundations of China under Grant Nos.10925522 and 10875001
文摘In a previous paper [Commun. Theor. Phys., [arxiv：hep-ph/11081451]], guish poles of different dynamical origin, in unitarized amplitudes of ππ, K K system. that ＂A Breit-wigner resonance should exhibit two poles on different Riemann sheets axis when Nc = ∞＂. In this paper, we extend our previous work [Commun. Theor. to the ππ-KK=ηη three channel system. We reconfirm most of the predictions in our Phys., [arxiv：hep-ph/11081451]]. Especially the fo（980） is of KK molecule nature. 0 Breit-WJgner type. we proposed a method to distinThat is based on the observation which meet each other on the real phys,[arXiv：hep,ph/11081451]]pres.ious work ： Theor. ther poles, including the σ,are of Breit-wigner type.
