Electronic and structural properties of alkali doped SWNT

Comprehensive experiments on structural and transport properties of alkali intercalated single walled carbon nanotubes (SWNT) are presented. The increasing electron density was measured as a shift of the Drude-edge in optical reflectivity in-situ with progressive doping. In saturation-doped samples the Drude-edge shifts into the visible (to 25,000 - 30,000 cm— 1 for potassium and rubidium doped samples) and the samples have a golden-brown color, similar to stage I graphite. X-ray diffraction reveals a crystalline rope structure with expanded lattice constant, similar to results of Duclaux et al. The change in the low temperature divergence of the resistivity after degassing at high temperature and high vacuum and after K-doping is studied in-situ

A thermodynamic basis for the electronic properties of molten semiconductors: the role of electronic entropy

The thermodynamic origin of a relation between features of the phase diagrams and the electronic properties of molten semiconductors is provided. Leveraging a quantitative connection between electronic properties and entropy, a criterion is derived to establish whether a system will retain its semiconducting properties in the molten phase. It is shown that electronic entropy is critical to the thermodynamics of molten semiconductor systems, driving key features of phase diagrams including, for example, miscibility gaps. Keywords: entropy; electronic entropy; thermopower; molten semiconductorUnited States. Air Force Office of Scientific Research (Grant FA9550-15-1-0046

Wide range optical studies on transparent SWNT films

We present transmission spectra from the far infrared through the ultraviolet region on freestanding SWNT films at temperatures between 40 and 300 K. Several interesting features are observed in the low-frequency part of the spectrum: the Drude-like frequency dependence of the metallic tubes as well as a (sample-dependent) peak in the conductivity around 0.01 eV. We also studied the accidental nitrate doping of the SWNT samples during purification by nitric acid. Asprepared purified samples exhibit increased metallic absorption and decreased interband transitions; these features disappear on heating in vacuum

Chemical doping of individual semiconducting carbon-nanotube ropes

We report the effects of potassium doping on the conductance of individual semiconducting single-walled carbon nanotube ropes. We are able to control the level of doping by reversibly intercalating and de-intercalating potassium. Potassium doping changes the carriers in the ropes from holes to electrons. Typical values for the carrier density are found to be ∼100–1000 electrons/μm. The effective mobility for the electrons is μeff∼20–60 cm2 V-1 s-1, a value similar to that reported for the hole effective mobility in nanotubes [R. Martel et al., Appl. Phys. Lett. 73, 2447 (1998)]

De quoi la transparence est-elle le nom ? Le cas de The Suspicions of Mr Wicher

L’étude du “Style du Commun” dans l’essai documentaire de Kate Summerscale The Suspicions of Mr Whicher or the Murder at Road Hill House permet de montrer ce qu’est la macrostylistique. Inspirée de la linguistique de l’énonciation et d’une philosophie du langage prenant en compte les interactions Langage ↔ Monde, la macrostylistique repose sur l’étude du langage dans son contexte large. Elle mène à une meilleure compréhension et à une interprétation des deux sociétés dont il est ici question : la société du XIXe siècle et celle du XXIe siècle. Cet essai documentaire mène l’enquête du meurtre du petit Saville Kent à Road Hill House en 1860. Du point de vue thématique, cette histoire vraie, racontée comme une fiction, présente pratiquement tous les traits d’un roman policier. Du point de vue linguistique, le style semble « plat » et s’apparente à un style neutre ou commun. L’enquête linguistique des traits grammaticaux saillants, principalement syntaxiques, montera que le style, tout comme le genre de cette enquête à succès est hybride. Le livre se compose d’un grafting de citations innombrables. La syntaxe est principalement hypotactique. L’enquête stylistique contextualisée de ce genre hybride mènera au paramétrage du « Style du Commun » du XXIe siècle.The study of the “style of the Common” in Kate Summerscale’s non-fiction The Suspicions of Mr Whicher or the Murder at Road Hill House will give an illustration of what macrostylistics is. Derived from the French school of enunciative linguistics and from a philosophy of language envisioning the two-way interaction between Language and the World (Language ↔ World) macrostylistics consists in the strong reading of a whole text, by studying its language within its broad context. Such an approach thus leads to a better understanding and interpretation of the two societies considered here, the 19th and the 21st century societies. This 21st century non-fiction investigates the widely talked about “murder at Road Hill House” of young Saville Kent, aged 3, in 1860. Thematically, this true story is told in the manner of a fiction and bears practically all the features of a detective novel. Linguistically, the style is apparently flat and could be considered as neutral or common. A linguistic investigation of the grammatical features, mainly syntactical, will show that the style, as well as the genre, of this much acclaimed investigation is hybrid. The book is composed of the grafting of innumerable quotations. The contextualised linguistic investigation of this actually puzzling grafted style will lead to the stylistic mapping of 21st century’s “Style of the Common”

Study of charge dynamics in transparent single-walled carbon nanotube films

We report the transmission over a wide frequency range (far infrared - visible) of pristine and hole-doped, free-standing carbon nanotube films at temperatures between 50 K and 300 K. Optical constants are estimated by Kramers-Kronig analysis of transmittance. We see evidence in the far infrared for a gap below 10 meV. Hole doping causes a shift of spectral weight from the first interband transition into the far infrared. Temperature dependence in both the doped and undoped samples is restricted to the far-infrared region.Comment: 6 pages, 4 figures, submitted to Phys. Rev. B v3: Fig. 2 replaced, changes in caption of Table II, minor changes in tex

Avant-propos

L’atelier de la Société de Stylistique Anglaise s’est déroulé à Lille dans les locaux de l’université Lille 3 – Charles de Gaulle du 21 au 23 mai 2010. Le thème du 50ème Congrès de la SAES, « À l’horizon », a permis aux participants de l’atelier de poursuivre l’élaboration d’une cartographie toujours en mouvement de la stylistique, pour mieux en tracer les contours actuels. Comme tout horizon, celui de la stylistique ne cesse d’évoluer au fil de l’avancement des travaux des stylisticiens. L’h..

Horizons du style : pratique et théorie de la transmission du stylistique

Cet article interroge les relations entre oralité et scripturalité et la transmission du savoir et du Stylistique dans l’enseignement et l’apprentissage de l’anglais langue étrangère. Le fondement de la linguistique appliquée (ou didactique des langues) est mise en relation avec une philosophie de la transmission. L’article s’appuie sur la praxis de l’oralisation de textes écrits sous forme de « performances » artistiques publiques.The aim of this paper is to question the relationships between orality and literacy and the transmission of knowledge and of the Stylistic in the teaching and learning of English as a foreign language. The basics of applied linguistics are confronted with a philosophy of transmission considering the experience of the silence of transmission. This paper is based on the praxis of the oralisation of written texts in public performances