2,863 research outputs found
Magnetic Field Effects on the Transport Properties of One-sided Rough Wires
We present a detailed numerical analysis of the effect of a magnetic field on
the transport properties of a `small-' one-sided surface disordered wire.
When time reversal symmetry is broken due to a magnetic field , we find a
strong increase with not only of the localization length but also of
the mean free path caused by boundary states. Despite this, the
universal relationship between and does hold. We also analyze the
conductance distribution at the metal-insulator crossover, finding a very good
agreement with Random Matrix Theory with two fluctuating channels within the
Circular Orthogonal(Unitary) Ensemble in absence(presence) of Comment: 5 pages, 4 figures, to appear in Phys. Rev.
Microinclusions in cassiterite of different deposits in western Spain
[Resumen] Se incluyen en este estudio casiteritas procedentes de distintos yacimientos de Salamanca y Extremadura que se han seleccionado en funciĂłn de sus diferentes caracteres: hábito, color, zonaci6n, tipologĂa genĂ©tica y composiciĂłn quĂmica. Se presenta la descripciĂłn microscĂłpica asĂ como la composiciĂłn quĂmica obtenida mediante microsonda de las casiteritas y sus microinclusiones. Cabe destacar una clara relaciĂłn entre la razĂłn Nb/Ta y el tipo genĂ©tico. Por otro lado, la razĂłn Fe/Mn es caracterĂstica propia del ambiente geoquĂmico de cada yacimiento. Las casiteritas ricas en Nb y Ta contienen microinclusiones de columbo-tantalita, las casiteritas ricas en Ti y Nb, ilmeno-rutilo y columbo-tantalita y las esencialmente, titanĂferas , rutilos.[Abstract] Cassiterites of different deposits in western Spain were selectioned for this study by different characteristics: colour, crystal habit, zonation, genetic type and chemical composition. Microscopic description and Microprobe analysis of cassiterites and microinclusions are presented. There is correlation between columbite-tantalite composition (Nb/Ta) and the genetic type; on the other hand, Fe/Mn depends of geochemical enviroment in ore deposits formation. The Nb-Ta cassiterites contain microinclusions of columbite-tantalite, the Ti-Nb cassiterites microinclusions of ilmeno-rutile and columbite-Tantalite and the Ti-cassiterites, rutiles
Anderson localization in a periodic photonic lattice with a disordered boundary
We investigate experimentally the light evolution inside a two-dimensional
finite periodic array of weakly- coupled optical waveguides with a disordered
boundary. For a completely localized initial condition away from the surface,
we find that the disordered boundary induces an asymptotic localization in the
bulk, centered around the initial position of the input beam.Comment: 3 pages, 4 figure
Artrosis vertebral en la población de La Encantada (Granátula de Calatrava, Ciudad Real, II milenio a. C.)
X Congreso Nacional de PaleopatologĂa. Univesidad AutĂłnoma de Madrid, septiembre de 200
Integral field spectroscopy of type-II QSOs at z=0.3-0.4
We present and analyse integral-field observations of six type-II QSOs with
z=0.3-0.4, selected from the Sloan Digital Sky Survey (SDSS). Two of our sample
are found to be surrounded by a nebula of warm ionized gas, with the largest
nebula extending across 8" (40 kpc). Some regions of the extended nebulae show
kinematics that are consistent with gravitational motion, while other regions
show relatively perturbed kinematics: velocity shifts and line widths too large
to be readily explained by gravitational motion. We propose that a ~20 kpc x20
kpc outflow is present in one of the galaxies. Possible mechanisms for
triggering the outflow are discussed. In this object, we also find evidence for
ionization both by shocks and the radiation field of the AGN.Comment: 6 pages, 5 figures, accepted by MNRAS Letter
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