Regular solutions to a supercritical elliptic problem in exterior domains

We consider the supercritical elliptic problem -\Delta u = \lambda e^u, \lambda > 0, in an exterior domain $\Omega = \mathbb{R}^N \setminus D$ under zero Dirichlet condition, where D is smooth and bounded in \mathbb{R}^N, N greater or equal than 3. We prove that, for \lambda small, this problem admits infinitely many regular solutions

Fundamentals and Applications of Surface-Enhanced Raman Spectroscopy (SERS)

When a molecule is adsorbed on some metallic nanostructured surfaces such as silver, copper or gold, it can undergo an enormous enhancement of the Raman signal giving rise to the so called Surface-Enhanced Raman Scattering (SERS). The high sensitivity of this effect allows an accurate structural study of adsorbates at very low concentrations. The SERS effect has historically been associated with the substrate roughness on two characteristic length scales. Surface roughness on the 10 to 100 nm length scale supports localized plasmon resonances which are considered as the dominant enhancement mechanism of SERS (Electromagnetic Enhancement Mechanism: SERS-EM). It is usually accepted that these electromagnetic resonances can increase the scattered intensity by an average factor of ca. 104 to 107. A secondary mechanism often thought to require atomic scale roughness is referred to as Charge Transfer (CT) Enhancement Mechanism (SERS-CT). This mechanism involves the photoinduced transfer of an electron from the metal to the adsorbate or vice versa and involves new electronic excited CT states which result from adsorbate–substrate chemical interactions. It is also estimated that such SERS-CT mechanism can enhance the scattering cross-section by a factor of ca. 10 to 102. These two mechanisms can operate simultaneously, depending on the particular systems and experimental conditions, making difficult to recognize each one and to estimate their relative magnitude in a particular spectrum.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

An MS-CASPT2 Study of the Photodecomposition of 4- Methoxyphenyl Azide. Role of Internal Conversion and Intersystem Crossing

Aryl azides photochemistry is strongly dependent on the substituent relative position, as has been studied by time resolved resonant Raman (TR3) spectroscopy for 4-methoxyphenyl azide and its isomer 3-methoxyphenyl azide. When irradiated at 266 nm, the former results in 4,4’-dimethoxyazobenzene whereas the latter forms 1,2-didehydroazepine. It is proposed that the key step of the reactions is the formation of a nitrene derivative. Recently, it has been proposed by us that nitrenes might have a relevant role in the Surface-Enhanced Raman Scattering (SERS) of p-aminothiophenol, however, the molecular mechanism is not well known in neither of these cases. Therefore, we studied the photodecomposition of 4-methoxyphenyl azide using multiconfigurational self-consistent field methods (MC-SCF) with the CAS-SCF and MS-CASPT2 approximations and calculated the resonant Raman spectra of the relevant species using a multi-state version of Albrecht’s vibronic theory. The results propose that the reaction follows a two steps sequence after irradiation at 266 nm: an intersystem crossing 21A’/23A’’ which decays through a 21A’/21A’’ conical intersection producing molecular nitrogen and triplet 4-methoxyphenyl nitrene in its ground state.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Desarrollo de la competencia lectora en secundaria

En México, los alumnos de telesecundaria obtienen los puntajes más bajos en competencia lectora. Este trabajo presenta los resultados de una investigación que tuvo como objetivo determinar la eficacia de un programa de comprensión lectora implementado en telesecundarias de una región marginada. El diseño fue experimental, con 16 grupos de octavo grado como grupo experimental y siete como control. Los resultados muestran que el grupo de control obtuvo los mismos puntajes antes y después de la intervención, mientras que el grupo experimental presentó una mejoría en la segunda evaluación, por lo que se considera que el programa fue eficaz.ITESO, A.C

On the origin of the jet-like radio/X-ray morphology of G290.1-0.8

The origin and evolution of supernova remnants of the mixed-morphology class is not well understood. Several remnants present distorted radio or X-ray shells with jet-like structures. G290.1-0.8 (MSH 11-61A) belongs to this class. We aim to investigate the nature of this supernova remnant in order to unveil the origin of its particular morphology. We based our work on the study of the X-ray emitting plasma properties and the conditions imposed by the cold interstellar medium where the remnant expanded. We use archival radio, HI line data and X-ray observations from XMM-Newton and Chandra observatories, to study G290.1-0.8 and its surrounding medium. Spatially resolved spectral analysis and mean photon energy maps are used to obtain physical and geometrical parameters of the source. Radio continuum and HI line maps give crucial information to understand the radio/X-ray morphology. The X-ray images show that the remnant presents two opposite symmetric bright spots on a symmetry axis running towards the NW-SE direction. Spectral analysis and mean photon energy maps confirm that the physical conditions of the emitting plasma are not homogeneous throughout the remnant. In fact, both bright spots have higher temperatures than the rest of the plasma and its constituents have not reached ionization equilibrium yet. HI line data reveal low density tube-like structures aligned along the same direction. This evidence supports the idea that the particular X-ray morphology observed is a direct consequence of the structure of the interstellar medium where the remnant evolved. However, the possibility that an undetected point-like object, as a neutron star, exists within the remnant and contributes to the X-ray emission cannot be discarded. Finally, we suggest that a supernova explosion due to the collapse of a high-mass star with a strong bipolar wind can explain the supernova remnant morphology.Comment: 8 pages, 6 figures. Accepted for publication in A&

Las creencias epistemológicas de alumnos y profesores de primero de secundaria

En este artículo se describen las creencias epistemológicas de alumnos y profesores de tres secundarias públicas en la zona metropolitana de Guadalajara. Se siguió el enfoque cuantitativo no experimental de tipo encuesta. El instrumento empleado fue el Inventario de Creencias Epistemológicas Sobre las Matemáticas desarrollado por Walker. La muestra incluyó 946 alumnos y diez profesores de primero de secundaria. Los resultados se analizaron desde la perspectiva cognitiva, particularmente desde los trabajos de Schommer y Perry, quienes consideran que las acciones pedagógicas y de aprendizaje de profesores y alumnos están influenciadas por su epistemología personal, entendida como un conjunto de creencias que afectan las maneras en las que las personas afrontan la tarea de aprender y enseñar. Los resultados muestran que tanto alumnos como profesores tienen creencias epistemológicas poco productivas para el aprendizaje o enseñanza de las matemáticas. Finalmente se analizan las implicaciones para el trabajo en el aula de secundaria.ITESO, A.C

El cuerpo imaginado.

Sin resume

Capacity Limits of Spectrum-Sharing in Hoyt (Nakagami-q) Fading Channels

A channel capacity analysis is presented in this work for a spectrum-sharing cognitive radio link in which the fading experienced by the signal is modeled with the Hoyt (Nakagami-q) distribution. Based on a novel formulation of the squared Hoyt distribution derived by the authors, simple expressions for the capacity of the secondary link in a number of scenarios of interest are derived, which are given in terms of easy-to-compute finite-range integrals of elementary functions. The effect of fading severity in the secondary transmitter-primary receiver (ST-PR) and secondary transmitter-secondary receiver (ST-SR) links, and the impact of different antenna gains on the system performance are analyzed. We show that in the presence of severe fading for the ST-PR link, the capacity of the ST-SR link is increased.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO. Fondos FEDER. European Union Marie-Curie COFUND U-mobility program