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A new generalized fractional Dirac soliton hierarchy and its fractional Hamiltonian structure 被引量:1
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作者 魏含玉 夏铁成 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第11期26-31,共6页
Based on the differential forms and exterior derivatives of fractional orders, Wu first presented the generalized Tu formula to construct the generalized Hamiltonian structure of the fractional soliton equation. We ap... Based on the differential forms and exterior derivatives of fractional orders, Wu first presented the generalized Tu formula to construct the generalized Hamiltonian structure of the fractional soliton equation. We apply the generalized Tu formula to calculate the fractional Dirac soliton equation hierarchy and its Hamiltonian structure. The method can be generalized to the other fractional soliton hierarchy. 展开更多
关键词 fractional calculus generalized Tu formula Dirac soliton hierarchy Hamiltonian struc- ture
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一种新型超宽带紧耦合天线阵列设计 被引量:1
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作者 张君 胡志慧 曲洪东 《海军航空工程学院学报》 2014年第2期127-130,共4页
针对紧耦合天线阵列(Tightly Coupled Array,TCA)安装于飞机、导弹、舰船等平台时接地板严重影响其阻抗带宽的问题,将栅格形阻性频率选择表面与交指型偶极子天线单元相结合,设计了一种新型多层结构的超宽带TCA。采用CST对加载与未... 针对紧耦合天线阵列(Tightly Coupled Array,TCA)安装于飞机、导弹、舰船等平台时接地板严重影响其阻抗带宽的问题,将栅格形阻性频率选择表面与交指型偶极子天线单元相结合,设计了一种新型多层结构的超宽带TCA。采用CST对加载与未加载栅格形阻性频率选择表面时TCA的性能进行了比较分析。结果表明:未加载时,受接地板影响其最佳阻抗带宽(VSWR〈2)为4.5:1(2.1~9.5GHz);加载后,TCA可克服接地板的影响,其阻抗带宽可达10.4:1(1.8~18.8GHz)。 展开更多
关键词 紧耦合天线阵列 超宽带 阻性频率选择表面 偶极子天线 多层结构
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Adaptive fuzzy nonlinear inversion-based control for uncertain chaotic systems 被引量:1
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作者 刘恒 余海军 向伟 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第12期123-129,共7页
This paper presents a robust output feedback control method for uncertain chaotic systems, which comprises a nonlinear inversion-based controller with a fuzzy robust compensator. The proposed controller eliminates the... This paper presents a robust output feedback control method for uncertain chaotic systems, which comprises a nonlinear inversion-based controller with a fuzzy robust compensator. The proposed controller eliminates the unknown nonlinear function by using a fuzzy system, whose inputs are not the state variables but feedback error signals. The underlying stability analysis as well as parameter update law design are carried out by using the Lyapunov-based technique. The proposed method indicates that the nonlinear inversion-based control approach can also be applied to uncertain chaotic systems. Theoretical results are illustrated through two simulation examples. 展开更多
关键词 chaotic systems nonlinear inversion-based control adaptive fuzzy control variable struc- ture control
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关于切丛和单位切球丛的度量的一个注记(英文)
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作者 李兴校 齐学荣 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2008年第4期829-838,共10页
In this paper we study a class of metrics with some compatible almost complex structures on the tangent bundle TM of a Riemannian manifold (M,g), which are parallel to those in [10]. These metrics generalize the class... In this paper we study a class of metrics with some compatible almost complex structures on the tangent bundle TM of a Riemannian manifold (M,g), which are parallel to those in [10]. These metrics generalize the classical Sasaki metric and Cheeger-Gromoll metric. We prove that the tangent bundle TM endowed with each pair of the above metrics and the corresponding almost complex structures is a locally conformal almost K¨ahler manifold. We also find that, when restricted to the unit tangent sphere bundle, these metrics and corresponding almost complex structures define new examples of contact metric structures. 展开更多
关键词 locally conformal almost K¨ahler manifold Vaisman manifold contact metric struc- ture Sasakian manifold.
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