It was proposed that perfect invisibility cloaks can be constructed for hiding objects from electromagnetic illumination (Pendry et al., Science 312, p. 1780). The cylindrical cloaks experimentally demonstrated (Schurig et al., Science 314, p. 997) and theoretically proposed (Cai et al., Nat. Photon. 1, p. 224) have however simplified material parameters in order to facilitate easier realization as well as to avoid infinities in optical constants. Here we show that the cylindrical cloaks with simplified material parameters inherently allow the zeroth-order cylindrical wave to pass through the cloak as if the cloak is made of a homogeneous isotropic Medium, and thus visible. To all high-order cylindrical waves, our numerical simulation suggests that the simplified cloak inherits some properties of the ideal cloak, but finite scatterings exist.
标签： invisibility constructed proposed electrom
上传时间： 2013-12-18
上传用户：13215175592
We analyze, both analytically and numerically, the effectiveness of cloaking an infinite cylinder from observations by electromagnetic waves in three dimensions. We show that, as truncated approximations of the ideal permittivity and permeability tensors tend towards the singular ideal cloaking fields, so that the anisotropy ratio tends to infinity, the D and B fields blow up near the cloaking surface. Since the metamaterials used to implement cloaking are based on effective Medium theory, the resulting large variation in D and B will pose a challenge to the suitability of the field averaged characterization of " and 碌. We also consider cloaking with and without the SHS (softand- hard surface) lining, shown in [6] to be theoretically necessary for cloaking in the cylindrical geometry. We demonstrate numerically that cloaking is significantly improved by the SHS lining, with both the far field of the scattered wave significantly reduced and the blow up of D and B prevented.
标签： effectiveness analytically numerically cloaking
上传时间： 2017-03-30
上传用户：zxc23456789
nTIM PATRICK has been working professionally as a software architect and developer for nearly 25 years. By day he develops custom business applications in Visual Basic for small to Medium- sized organizations. He is a Microsoft Certified Solution Developer (MCSD). In April 2007, Microsoft awarded Tim with its Most Valuable Professional (MVP) award for his work in sup- porting and promoting Visual Basic and its community of users. Tim received his under- graduate degree in computer science from Seattle Pacific University. You can contact him through his web site, www.timaki.com.
标签： professionally architect developer software
上传时间： 2013-12-26
上传用户：asdfasdfd
Digital Modulation Techniques are those echniques through which we convert digital signals into analog signal which can be transmitted through transmission Medium...this program demostrate some of the basics techniques
标签： Modulation Techniques echniques Digital
上传时间： 2013-12-23
上传用户：wyc199288
一个自适应控制方面的资料
标签： matlab
上传时间： 2015-03-16
上传用户：jingchao
Writing essays and dissertations can be a major concern for overseas students studying at English-Medium colleges and universities. Virtually all courses contain a large degree of written assessment and it is essential to ensure that your writing skills meet the necessary standard. Academic Writing is a new kind of writing course for all international students who have to write exams or coursework in English. This practical book thoroughly explains the writing process and covers all the key writing skills.
标签： Academic writing
上传时间： 2015-11-13
上传用户：blackbat
DnaSP DNA类比分析软件
标签： DnaSP
上传时间： 2016-07-19
上传用户：luwenkang
msp430The LDC1312 and LDC1314 are 2- and 4-channel, 1• Easy-to-use – minimal configuration required 12-bit inductance to digital converters (LDCs) for • Measure up to 4 sensors with one IC inductive sensing solutions. With multiple channels • Multiple channels support environmental and and support for remote sensing, the LDC1312 and aging compensation LDC1314 enable the performance and reliability benefits of inductive sensing to be realized at minimal• Multi-channel remote sensing provides lowest cost and power. The products are easy to use, onlysystem cost requiring that the sensor frequency be within 1 kHz • Pin-compatible Medium and high-resolution and 10 MHz to begin sensing. The wide 1 kHz to 10 options MHz sensor frequency range also enables use of very small PCB coils, further reducing sensing– LDC1312/4: 2/4-ch 12-bit LDC solution cost and size.– LDC1612/4: 2/4-ch 28
上传时间： 2016-07-22
上传用户：tongmoonsky
Windows编程扫雷源代码，,应用面向对象的可视化编程语言Visual C++给出了个功能模块的具体实现方法,并提供了编写小游戏程序的一般方法和Visual C++的一些使用技巧。
上传时间： 2016-12-17
上传用户：chenluowen
完整的 企业进销存管理系统， java 通用进销存系统。很完整的说明文档和源码以及源程序
上传时间： 2017-01-17
上传用户：zs52611984
