Tunable I-shaped metamaterial by loading varactor diode for reconfigurable antenna

A tunable metamaterial by employing I-shaped metamaterial with loaded varactor diode is presented in this paper and the phase of emitting wave modulated by the varactor diode is demonstrated. We have proved that the energy loss is relatively low when the working frequency is chosen to be away from the resonance frequency of the I-shaped metamaterial. By using the metamaterial, a pattern reconfigurable antenna is designed based on arrayed antennas theory. Simulations results show that the radiation pattern can be tuned to different angles by properly arranging the linear phase difference of adjacent regions.     

SEM-EDXA分析不同生长应力木材细胞壁微区木质素沉积

选取具不同生长应力水平的人工林尾巨桉(Eucalyptus uroph ylla×E.grandis)正常木为研究对象,借助场发射环境扫描电子显微镜系统,结合以溴元素做标记的X射线能谱分析技术,分析了尾巨桉细胞壁微区木质素沉积与生长应力的关系.研究结果表明,木纤维细胞壁各微区间木质素含量的大小关系与生长应力高低无关,其...     

Uniform estimate for the tail probabilities of randomly weighted sums

Several authors have studied the uniform estimate for the tail probabilities of randomly weighted sumsa.ud their maxima. In this paper, we generalize their work to the situation thatis a sequence of upper tail asymptotically independent random variables with common distribution from the is a sequence of nonnegative random variables, independent of and satisfying some regular conditions. Moreover. no additional assumption is required on the dependence structureof {θi,i≥ 1）.     

Low regularity solutions,blowup, and global existence for a generalization of Camassa–Holm‐type equation

We consider a generalization of Camassa–Holm‐type equation including the Camassa–Holm equation and the Novikov equation. We mainly establish the existence of solutions in lower order Sobolev space with . Then, we present a precise blowup scenario and give a global existence result of strong solutions. Copyright © 2013 John Wiley & Sons, Ltd.     

Oscillatory traveling waves of polytropic filtration equation with generalized Fisher–KPP sources

The polytropic filtration equation with generalized Fisher–KPP sources is considered. We will show that the equation may have finite times oscillatory traveling waves, and try to give a complete classification by virtue of a singular exponent in the source according to the finiteness of the oscillatory times of traveling waves.     

On the third gap for proper holomorphic maps between balls

Let $F$ be a proper rational map from the complex ball $\mathbb B ^n$ into $\mathbb B ^N$ with $n>7$ and $3n+1 \le N\le 4n-7$ . Then $F$ is equivalent to a map $(G, 0, \dots , 0)$ where $G$ is a proper holomorphic map from $\mathbb B ^n$ into $\mathbb B ^{3n}$ .     

A cell functional minimization scheme for domain decomposition method on non-orthogonal and non-matching meshes

We are interested in a robust and accurate domain decomposition algorithm with interface conditions of Robin type on non-matching multiblock grids using a cell functional minimization scheme, which has a good performance on non-orthogonal meshes. In order to treat the non-matching grids at the interface, we introduce the \(L^2\) projection operator to ensure weak continuity of the primary unknown and of the normal flux across the non-matching interface. Furthermore, we prove the wellposedness of local and global problems and obtain as well an error estimate of first order in a discrete \(H^{1}\) -norm only using the \(L^{2}\) projection operator on the non-matching interface, as done in the matching case. Numerical results are presented in confirmation of the theoretical results.     

On the first eigenvalue of Finsler manifolds with nonnegative weighted Ricci curvature

We prove that for a compact Finsler manifold M with nonnegative weighted Ricci curvature,if its first closed(resp.Neumann)eigenvalue of Finsler-Laplacian attains the sharp lower bound,then M is isometric to a circle(resp.a segment).Moreover,a lower bound of the first eigenvalue of Finsler-Laplacian with Dirichlet boundary condition is also estimated.These generalize the corresponding results in recent literature.