排序方式: 共有24条查询结果,搜索用时 15 毫秒
11.
We study the absorption problem for a massless scalar field propagating in general static spherically-symmetric black holes with a global monopole. The absorption cross section expression is provided using a partial-wave method, which permits us to make an elegant and powerful resummation of the absorption cross section, and to extract the physical information encoded in the sum over the partial-wave contributions. 相似文献
12.
13.
针对高频地波雷达天线阵通常十分庞大的问题,根据海洋回波理论,利用单个到达角海洋回波进行雷达通道幅度相位的自校准,应用适合便携式天线系统的信源估计方法,采用MUSIC(MUltiple Slgnal C1assification)算法反演海流信息,研究了交叉环/单极子天线在高频地波雷达近海海洋表面流探测中的应用,将探测结果与采用相控阵接收的高频地波雷达OSMAR2000的探测结果进行对比,径向流速平均偏差为1.3cm/s,说明近海海洋表面流探测采用便携式的小天线可取得与传统相控阵相同的效果. 相似文献
14.
针对某型飞机研制要求,设计了一种基于四分之一波长平面单极子的机载通信天线,重点阐述了天线辐射体设计、匹配网络设计和闪电防护设计等内容。通过地面测试和装机试飞验证,表明了该机载通信天线性能良好,完全能够取代现役英国37R-2型通信天线。 相似文献
15.
设计了一种应用于WLAN和WiMAX的多频带印刷单极子天线。该天线制作在以聚四氟乙烯为材料的基板上,天线正面部分具有三个条带结构,背面则添加了带有矩形槽的反射地结构以改进天线的阻抗匹配。利用三维电磁仿真软件(Ansoft HFSS13.0)进行仿真,并将该天线通过SMA连接器连接到矢网仪(Agilent Technologies N5230C10MHz~20GHz)进行测试。实际测试结果与仿真结果基本吻合,符合设计要求,验证了设计的正确性。 相似文献
16.
The space-time monopole equation is the reduction of anti-self-dual Yang-Mills equations in R2,2 to R2,1. This equation is a non-linear wave equation, and can be encoded in a Lax pair. An equivalent Lax pair is used by Dai and Terng to construct monopoles with continuous scattering data, and then the equation can be linearized by the scattering data, allowing one to use the inverse scattering method to solve the Cauchy problem with rapidly decaying small initial data. In this paper, we use the terminology of holomorphic bundle and transversality of certain maps, parametrized by initial data, to give more initial data, with which we can use scattering method to solve the Cauchy problem of the monopole equation up to gauge transformation. 相似文献
17.
18.
针对非均匀性地层地质力学评价和地质导向钻井的需要,研究了随钻单极子声波的方位特性和反射声场特征,并研制了随钻声波测量装置.建立了不同方向速度模型井和反射声场模型,数值模拟了两个模型的单极子声波传播特征,使用单极子声源发射和偏极子接收器接收的测量模式,分别获得了波速周向变化图和反射波的方位特征.模拟结果表明,纵波对地层方... 相似文献
19.
杨亦松 《数学物理学报(B辑英文版)》2010,(6):1975-2005
Monopoles and vortices are well known magnetically charged soliton solutions of gauge field equations. Extending the idea of Dirac on monopoles, Schwinger pioneered the concept of solitons carrying both electric and magnetic charges, called dyons, which are useful in modeling elementary particles. Mathematically, the existence of dyons presents interesting variational partial differential equation problems, subject to topological constraints. This article is a survey on recent progress in the study of dyons. 相似文献
20.