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独立设计了一款S波段,带宽115 M的微带天线,并用其组成了两种阵列天线形式,分析了其单元耦合特性的不同,并用电屏蔽介质分析了去耦对辐射场的影响.进而,从软件仿真和理论分析两个角度重点分析了微带天线辐射场直接合成的方向图特性,得到了增益、辐射场、主副瓣与单元间距的关系,对未来设计微带阵列天线起到了前期预测天线特性的参考... 相似文献
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The shape equation of lipid membranes is a fourth-order partial differential equation. Under the axisymmetric condition, this equation was transformed into a second-order ordinary differential equation(ODE) by Zheng and Liu(Phys. Rev.E 48 2856(1993)). Here we try to further reduce this second-order ODE to a first-order ODE. First, we invert the usual process of variational calculus, that is, we construct a Lagrangian for which the ODE is the corresponding Euler–Lagrange equation. Then, we seek symmetries of this Lagrangian according to the Noether theorem. Under a certain restriction on Lie groups of the shape equation, we find that the first integral only exists when the shape equation is identical to the Willmore equation, in which case the symmetry leading to the first integral is scale invariance. We also obtain the mechanical interpretation of the first integral by using the membrane stress tensor. 相似文献
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