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 …

I and i

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。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

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

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

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.

/pdf/surface-plasmon-subwavelength-optics-5e55p12p4o.pdf

Surface plasmon subwavelength optics

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

Phd by thesis

Sensing motion and distinguishing its source as human or nonhuman, with high precision, has tremendous applications in a variety of areas from health monitoring to energy efficiency. One strategy to achieve this goal is to detect the small motion of breathing, which is a consistent indicator of human presence. Among the many smart sensing schemes proposed, microwave and RF sensors have shown great promise due to their simplicity, privacy, and effective range. In this paper, we propose the use of a dynamic metasurface antenna (DMAs) as an alternative hardware platform for sensing motion inside a residential setting using microwave signals. The proposed device is a single-port planar cavity that excites an array of electronically-tunable metamaterial elements. The DMA can generate spatially diverse patterns at a single frequency, avoiding complexities related to wideband operation or high hardware costs of antenna arrays. We demonstrate that it is capable of detecting minute movements, such as breathing emulated by a mannequin, to distinguish human presence. This motion can be detected whether the target is in the the sensor’s direct line of sight or out of the direct line of sight. Furthermore, we show that the DMA sensing platform requires a single noise-floor calibration and can operate in different room geometries or configurations (e.g. when furniture is displaced). The proposed DMA-sensor with its single frequency operation and simple hardware is an appealing alternative hardware for intruder detection, human presence detection/activity recognition in smart homes, or seamless health monitoring.

/pdf/detecting-motion-in-a-room-using-a-dynamic-metasurface-2xv9j9e9gt.pdf

Detecting Motion in a Room Using a Dynamic Metasurface Antenna

A nano-antenna composed of a particle and a polarizable surface provides control of the spatial distribution and high enhancement of Raman scattering. This structure may serve as a stable platform for single molecule detection.

Raman antenna formed by molecule/plasmonic nanostructure hybrid system

Due to the recent experimental validations of left-handed metamaterials, negative refractive index has now become recognized as a new parameter space for the electromagnetic response of materials. Because materials with negative index behave quite differently than materials with positive index, many familiar electromagnetic phenomena must be reconsidered. Having established now the scientific basis of negative index, the effort of the community is turning toward the practical realization of both the predicted scientific phenomena and associated applications. In both of these pursuits, the ability to design, characterize and fabricate negative index materials is critical; we can consider the current status of negative refraction in some sense a materials issue, as our ability to demonstrate the predicted phenomena is linked to the quality of metamaterials we can produce. In this paper we consider several issues associated with the design and simulation of negative index metamaterials. Keywords: Negative index, left-handed materials, metamaterials

Design of metamaterials with negative refractive index

The weak scattering approximation is used when designing optical media that couple fields together, but to account for the interactions of multiple fields in a volume or to achieve the best efficiency, the solution must be consistent with Maxwell’s equations. We describe a method based on the variational formulation of Maxwell’s equations typically employed in the finite element method (FEM) that finds both the fields and the medium that couples incident and scattered fields together, and so can be considered an extension of the FEM when both the field and the medium are allowed to vary. The method iteratively updates estimates of the field and the medium and can be readily implemented. We demonstrate designs of diffractive and refractive elements that couple fields together using an iteratively updated finite-difference-frequency-domain (FDFD) solution. Such methods that are fully consistent with Maxwell’s equations are needed to design metamaterials that fully exploit strongly interacting metamaterial elements.

Inverse scattering with a non self-adjoint variational formulation.

NSTX high-k scattering system has been extensively utilized in studying the microturbulence and coherent waves. An absolute calibration of the scattering system was performed employing a new millimeter-wave source and calibrated attenuators. One of the key parameters essential for the calibration of the multichannel scattering system is the interaction length. This interaction length is significantly different from the conventional one due to the curvature and magnetic shear effect.

David R. Smith

Papers

Detecting Motion in a Room Using a Dynamic Metasurface Antenna

Raman antenna formed by molecule/plasmonic nanostructure hybrid system

Design of metamaterials with negative refractive index

Inverse scattering with a non self-adjoint variational formulation.

Spatial resolution study and power calibration of the high-k scattering system on NSTX.