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Full-Text Articles in Physical Sciences and Mathematics

A New Pathway For Communicating The 11-Year Solar Cycle Signal To The Qbo, Eugene C. Cordero, Terrence R. Nathan Sep 2005

A New Pathway For Communicating The 11-Year Solar Cycle Signal To The Qbo, Eugene C. Cordero, Terrence R. Nathan

Eugene C. Cordero

[1] The response of the equatorial quasi-biennial oscillation (QBO) to zonal-mean ozone perturbations consistent with the 11-year solar cycle is examined using a 2 1/2 dimensional model of the tropical stratosphere. Unique to this model are wave-ozone feedbacks, which provide a new, nonlinear pathway for communicating solar variability effects to the QBO. Model simulations show that for zonal-mean ozone perturbations representative of solar maximum (minimum), the diabatic heating due to the wave-ozone feedbacks is primarily responsible for driving a slightly stronger (weaker) QBO circulation and producing a slightly shorter (longer) QBO period. These results, which are explained via an analytical …


Mass-To-Light Ratio Gradients In Early-Type Galaxy Haloes, N. R. Napolitano, M. Capaccioli, Aaron J. Romanowsky, N. G. Douglas, M. R. Merrifield, K. Kuijken, M. Arnaboldi, O. Gerhard, K. C. Freeman Jan 2005

Mass-To-Light Ratio Gradients In Early-Type Galaxy Haloes, N. R. Napolitano, M. Capaccioli, Aaron J. Romanowsky, N. G. Douglas, M. R. Merrifield, K. Kuijken, M. Arnaboldi, O. Gerhard, K. C. Freeman

Aaron J. Romanowsky

Owing to the fact that the near future should see a rapidly expanding set of probes of the halo masses of individual early-type galaxies, we introduce a convenient parameter for characterizing the halo masses from both observational and theoretical results: ∇ℓϒ, the logarithmic radial gradient of the mass-to-light ratio. Using halo density profiles from Λ-cold dark matter (CDM) simulations, we derive predictions for this gradient for various galaxy luminosities and star formation efficiencies εSF. As a pilot study, we assemble the available ∇ℓϒ data from kinematics in early-type galaxies – representing the first unbiased study of halo masses in a …


Characterization Of The Electronic Excited-State Energetics And Solution Structure Of Lanthanide(Iii) Complexes With The Polypyridine Ligand 6,6'-Bis[Bis(2-Pyridylmethyl)Aminomethyl]-2,2'-Bipyridine, Gilles Muller, P. Gawryszewska, J. Sokolnicki, A. Dossing, J. P. Riehl, J. Legendziewicz Jan 2005

Characterization Of The Electronic Excited-State Energetics And Solution Structure Of Lanthanide(Iii) Complexes With The Polypyridine Ligand 6,6'-Bis[Bis(2-Pyridylmethyl)Aminomethyl]-2,2'-Bipyridine, Gilles Muller, P. Gawryszewska, J. Sokolnicki, A. Dossing, J. P. Riehl, J. Legendziewicz

Gilles Muller

Absorption, emission, and excitation spectra for solid-state and solution of Tb(III), Dy(III), and Gd(III) complexes with the polypyridine ligand 6,6‘-bis[bis(2-pyridylmethyl)-aminomethyl]-2,2‘-bipyridine (C36H34N8) are presented. Measurements of excited-state lifetimes and quantum yields in various solvents at room temperature and 77 K are also reported and used to characterize the excited-state energetics of this system. Special attention is given to the characterization of metal-to-ligand energy transfer efficiency and mechanisms. The measurement of circularly polarized luminescence (CPL) from the solution of the Dy(III) complex following circularly polarized excitation confirms the chiral structure of the complexes under study. No CPL is present in the luminescence …


Yba2cu3o7 Electro-Magneto-Optic Effects In Ba L2,3 X-Ray Absorption Near Tc, Juana Vivó Acrivos Jan 2005

Yba2cu3o7 Electro-Magneto-Optic Effects In Ba L2,3 X-Ray Absorption Near Tc, Juana Vivó Acrivos

Juana Vivó Acrivos

The onset of electro magneto-optic effects, observed at the Ba L2,3 edges synchrotron X-ray absorption by a YBa2Cu3O7 single crystal, 10 K above the transition temperature to superconductivity, Tc ~ 92 K is used to identify the role played by the Ba donor layer in the transition to superconductivity in the CuO2 layers. Negative permeability leads to Faraday rotation of the transmitted beam below T = 112 to 56 K for the 22 μm thick single crystal (c-axis orientation of 8π/18 relative to εX-rays) and sharp changes in the density of empty final states lead to zero transmitted radiation in …