Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Direct Numerical Simulation of Three-Dimensional Richtmyer--Meshkov Instability
Direct Numerical Simulation of Three-Dimensional Richtmyer-Meshkov Instability

FU De-Xun,MA Yan-Wen,LI Xin-Liang,

中国物理快报 , 2008,
Abstract: Direct numerical simulation (DNS) is used to study flow characteristics after interaction of a planar shock with a spherical media interface in each side of which the density is different. This interfacial instability is known as theRichtmyer--Meshkov (R-M) instability. The compressible Navier--Stoke equations are discretized with group velocity control (GVC) modified fourth order accurate compact difference scheme. Three-dimensional numerical simulations are performed for R-M instability installed passing a shock through a spherical interface. Based on numerical results the characteristics of 3D R-Minstability are analysed. The evaluation for distortion of the interface, the deformation of the incident shock wave and effects of refraction, reflection and diffraction are presented. The effects of the interfacial instability on produced vorticity and mixing is discussed.
Strong Resonance of Light in a Cantor Set  [PDF]
Naomichi Hatano
Physics , 2005, DOI: 10.1143/JPSJ.74.3093
Abstract: The propagation of an electromagnetic wave in a one-dimensional fractal object, the Cantor set, is studied. The transfer matrix of the wave amplitude is formulated and its renormalization transformation is analyzed. The focus is on resonant states in the Cantor set. In Cantor sets of higher generations, some of the resonant states closely approach the real axis of the wave number, leaving between them a wide region free of resonant states. As a result, wide regions of nearly total reflection appear with sharp peaks of the transmission coefficient beside them. It is also revealed that the electromagnetic wave is strongly enhanced and localized in the cavity of the Cantor set near the resonant frequency. The enhancement factor of the wave amplitude at the resonant frequency is approximately $6/|\eta_\mathrm{r}|$, where $\eta_\mathrm{r}$ is the imaginary part of the corresponding resonant eigenvalue. For example, a resonant state of the lifetime $\tau_\mathrm{r}=4.3$ms and of the enhancement factor $M=7.8\times10^7$ is found at the resonant frequency $\omega_\mathrm{r}=367$GHz for the Cantor set of the fourth generation of length L=10cm made of a medium of the dielectric constant $\epsilon=10$.
Non-commutative geometry and covariance: from the quantum plane to the quantum tensors  [PDF]
J. A. de Azcarraga,P. P. Kulish,F. Rodenas
Physics , 1994, DOI: 10.1007/BF01690450
Abstract: Reflection and braid equations for rank two $q$-tensors are derived from the covariance properties of quantum vectors by using the $R$-matrix formalism.
Calligrammes animés
Alexandra Saemmer
Trans : Revue de Littérature Générale et Comparée , 2006,
Abstract: Depuis que mots et images prolifèrent, s’hypertextualisent et s’animent sur support numérique, certains auteurs ont commencé à rêver à une nouvelle proximité sémantique entre mots et images. Sur la surface visible de l’écran, le mot s’anime comme une image, acquiert de nouvelles dimensions graphiques et plastiques. Ce transport du texte vers un autre régime sémiotique fait penser à celui qui s’effectue dans le calligramme : En s’animant, le mot ne s’acharne pas seulement à rendre sensibles des choses mouvantes au niveau de son contenu , mais il inscrit ce mouvement au niveau de son contenant , de sa matière écrite. C’est, entre autres, à cause de ces nouvelles contaminations intersémiotiques entre texte et image que Xavier Malbreil a intitulé sa création numérique 10 poèmes en 4 dimensions. à travers une analyse détaillée des calligrammes animés dans l’ uvre de Xavier Malbreil, mon article propose une réflexion autour d’une éventuelle présence de la quatrième dimension dans l’espace-réseau. Ever since images and words can be animated and hypertextualized on electronic supports, authors have started dreaming about a new semantic proximity between words and images. On the visible surface of the screen, words have become animated like images, and have acquired a new graphic dimension. This transfer of text onto another semiotic mode is reminiscent of the way calligrammes work. In becoming animated, the word not only makes visible a dynamic semantic “content”, but it also inscribes this movement on the level of its “container”, the written matter. Because of these new intersemiotic “contaminations” between text and image, Xavier Malbreil entitled his eletronic creation 10 poems in four dimensions. Through a detailed analysis of the animated calligrammes in Xavier Malbreil’s work, my article offers a reflection about the possible presence of a fourth dimension on the web. Cuando las palabras y las imágenes comenzaron a proliferar, a “hipertextualizarse” y a animarse gracias a un suporte numérico, los escritores comenzaron a idear una nueva proximidad semántica entre palabras e imágenes. Sobre la superficie visible de la pantalla, la palabra cobra vida como una imagen, adquiere nuevas dimensiones gráficas y plásticas. Esta transición del texto hacia otro régimen semiótico remite al que se lleva a cabo en el ejercicio del caligrama. Al animarse, la palabra pretende volver sensibles no sólo aquellas cosas que se mueven respecto a su “contenido”, sino que también inscribe dicho movimiento al nivel de su “conteniente”, de su sustancia escrita. Esta, ent
Coulomb Blockade Oscillations in the Thermopower of Open Quantum Dots  [PDF]
A. V. Andreev,K. A. Matveev
Physics , 2000, DOI: 10.1103/PhysRevLett.86.280
Abstract: We consider Coulomb blockade oscillations of thermoelectric coefficients of a single electron transistor based on a quantum dot strongly coupled to one of the leads. Analytic expression for the thermopower as a function of temperature $T$ and the reflection amplitude $r$ in the quantum point contact is obtained. Two regimes can be identified: $T \ll E_C|r|^2$ and $T \gg E_C |r|^2$, where $E_C$ is the charging energy of the dot. The former regime is characterized by weak logarithmic dependence of the thermopower on the reflection coefficient, in the latter the thermopower is linear in the reflection coefficient $|r|^2$ but depends on temperature only logarithmically.
Narrow Line Seyfert 1 galaxies at hard X-rays  [PDF]
F. Panessa,A. De Rosa,L. Bassani,A. Bazzano,A. Bird,R. Landi,A. Malizia,G. Miniutti,M. Molina,P. Ubertini
Physics , 2011, DOI: 10.1111/j.1365-2966.2011.19268.x
Abstract: Narrow Line Seyfert 1 (NLSy1) galaxies are a peculiar class of type 1 AGN (BLSy1). The X-ray properties of individual objects belonging to this class are often extreme and associated with accretion at high Eddington ratios. Here we present a study on a sample of 14 NLSy1 galaxies selected at hard X-rays (> 20 keV) from the fourth INTEGRAL/IBIS catalogue. The 20-100 keV IBIS spectra show hard X-ray photon indeces flatly distributed (Gamma_{20-100 keV} ranging from ~1.3 to ~3.6) with an average value of = 2.3+/-0.7, compatible with a sample of hard X-ray BLSy1 average slope. Instead, NLSy1 show steeper spectral indeces with respect to BLSy1 when broad-band spectra are considered. Indeed, we combine XMM-Newton and Swift/XRT with INTEGRAL/IBIS data sets to obtain a wide energy spectral coverage (0.3-100 keV). A constraint on the high energy cut-off and on the reflection component is achieved only in one source, Swift J2127.4+5654 (E_{cut-off} ~ 50 keV, R=1.0{+0.5}_{-0.4}). Hard X-ray selected NLSy1 do not display particularly strong soft excess emission, while absorption fully or partially covering the continuum is often measured as well as Fe line emission features. Variability is a common trait in this sample, both at X-ray and at hard X-rays. The fraction of NLSy1 in the hard X-ray sky is likely to be ~15%, in agreement with estimates derived in optically selected NLSy1 samples. We confirm the association of NLSy1 with small black hole masses with a peak at 10^{7} M_{dot} in the distribution, however hard X-ray NLSy1 seem to occupy the lower tail of the Eddington ratios distribution of classical NLSy1.
Higher cumulants of voltage fluctuations in current-biased diffusive contacts  [PDF]
K. E. Nagaev
Physics , 2003,
Abstract: The third and fourth cumulants of voltage in a current-biased diffusive metal contact of resistance $R$ are calculated for arbitrary temperatures and voltages using the semiclassical cascade approach. The third cumulant equals $e^2R^3I/3$ at high temperatures and $4e^2R^3I/15$ at low temperatures, whereas the fourth cumulant equals $2e^2R^3T/3$ at high temperatures and $(34/105)e^3R^4I$ at low temperatures.
Duality Induced Reflections and CPT  [PDF]
Heinrich Saller
Physics , 1999,
Abstract: The linear particle-antiparticle conjugation $\ty C$ and position space reflection $\ty P$ as well as the antilinear time reflection $\ty T$ are shown to be inducable by the selfduality of representations for the operation groups $\SU(2)$, $\SL(\C^2)$ and $\R$ for spin, Lorentz transformations and time translations resp. The definition of a colour compatible linear $\ty{CP}$-reflection for quarks as selfduality induced is impossible since triplet and antitriplet $\SU(3)$-representations are not linearly equivalent.
Trigonometric sl(2) Gaudin model with boundary terms  [PDF]
N. Cirilo António,N. Manojlovi?,Z. Nagy
Physics , 2013, DOI: 10.1142/S0129055X13430046
Abstract: We review the derivation of the Gaudin model with integrable boundaries. Starting from the non-symmetric R-matrix of the inhomogeneous spin-1/2 XXZ chain and generic solutions of the reflection equation and the dual reflection equation, the corresponding Gaudin Hamiltonians with boundary terms are calculated. An alternative derivation based on the so-called classical reflection equation is discussed.
Levinas y las Ciencias Sociales: fundamentos epistémicos desde la alteridad
Jaramillo Echeverri,Luis Guillermo; Aguirre García,Juan Carlos;
Folios , 2010,
Abstract: in order to consider the possibility of assuming them as the epistemic foundations of social sciences, this paper presents some of the essential theses of the french-lithuanian philosopher, emmanuel levinas. in particular, the theses that support his philosophy of alterity are discussed. the paper is organized in five sections: first, levinas is brought into the reflection framework about social sciences. second, third and fourth sections go into the "levinasian" proposal, under the categories of totality, face and language, respectively. finally, some epistemic views are presented to suggest further developments rather than final explanations
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.