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David R. Smith

Bio: David R. Smith is an academic researcher from Duke University. The author has contributed to research in topics: Metamaterial & Antenna (radio). The author has an hindex of 110, co-authored 881 publications receiving 91683 citations. Previous affiliations of David R. Smith include Brunel University London & Princeton University.


Papers
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Proceedings ArticleDOI
01 Jun 2016
TL;DR: The initial results of using a dipole-based simulation method for a finite lens, composed of split-ring-resonators, establish a platform to improve the metasurface design process, given the fact that no periodic boundary condition is required.
Abstract: A dipole-based simulation method is presented to study the effects of edges on finite metasurfaces. This technique can accurately account for the physical limitations associated with fabrication and thereby leads to high fidelity predictions needed in practical applications. Moreover, it establishes a platform to improve the metasurface design process, given the fact that no periodic boundary condition is required and the interaction between different meta-atoms within the surface is taken into account. This paper presents the initial results of using this technique for a finite lens, composed of split-ring-resonators. The dipole moments are found and the far-field is computed and compared with full-wave simulations.

4 citations

Proceedings ArticleDOI
17 May 1993
TL;DR: The first 5-cell, 433-MHz accelerator cavity for the APLE free electron laser experiment at Boeing has been assembled and tuned as mentioned in this paper, and the cavity is being readied for its initial vacuum bakeout, during which the constituents of the residual gas will be monitored.
Abstract: The first 5-cell, 433-MHz accelerator cavity for the APLE free electron laser experiment at Boeing has been assembled and tuned. Low power RF measurements indicate that the critical electrical parameters (Q/sub 0/, f, and /spl beta/) for the accelerator and TM/sub 110/-like modes are consistent with expectations based on measurements made on an 800-MHz model cavity. The cavity is being readied for its initial vacuum bakeout, during which the constituents of the residual gas will be monitored. First application of high power RF is scheduled for late summer of 1993. >

4 citations

Posted Content
TL;DR: In this paper, the authors proposed a method to enable an optical amplification of coherent Raman spectroscopy signals by converting a spectral frequency shift imparted by an impulsive coherent-raman excitation to a change in a probe pulse transit time, which is detected through the phase of a radio frequency electronic signal measured at a harmonic of the probe pulse train.
Abstract: We introduce the first method to enable an optical amplification of a coherent Raman spectroscopy signal called radio frequency Doppler Raman spectroscopy. Doppler Raman measurements amplify the optical signals in coherent Raman spectroscopy by converting a spectral frequency shift imparted by an impulsive coherent Raman excitation to a change in a probe pulse transit time. This transit time perturbation is detected through the phase of a radio frequency electronic signal measured at a harmonic of the probe pulse train. By exploiting this new capability to scale the signal of a coherent Raman spectroscopic signal, we open the potential to detect very weak Raman spectroscopy signals that are currently not observable due to limits of illumination intensity imposed by laser damage to the specimen.

3 citations

Journal ArticleDOI
TL;DR: In this paper, the authors apply an analytic theory toward the design of a varactor-loaded split-ring resonator metacrystals, having nonlinear electromagnetic properties on demand.
Abstract: We apply an analytic theory [New J Phys12, 093010 (2010)] toward the design of varactor-loaded split-ring resonator metacrystals, having nonlinear electromagnetic properties on demand The design methodology here is shown to be efficient and is validated by the excellent agreement between the analytically predicted and experimentally measured harmonic generation The analytic formulas enable a path toward optimization of nonlinear properties, which we demonstrate by varying the spacing of the metamaterial elements to maximize the second-order nonlinear susceptibility of the system

3 citations


Cited by
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Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: A review of gold nanoparticles can be found in this article, where the most stable metal nanoparticles, called gold colloids (AuNPs), have been used for catalysis and biology applications.
Abstract: Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

11,752 citations

Journal ArticleDOI
14 Aug 2003-Nature
TL;DR: By altering the structure of a metal's surface, the properties of surface plasmons—in particular their interaction with light—can be tailored, which could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved.
Abstract: Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons--in particular their interaction with light--can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.

10,689 citations

Journal ArticleDOI
01 Apr 1988-Nature
TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

9,929 citations