Search results for " GAP"
showing 10 items of 811 documents
The spectrum of weakly coupled map lattices
1998
We consider weakly coupled analytic expanding circle maps on the lattice Zd (for d 2 l), with small coupling strength c and coupling between two sites decaying exponentially with the distance. We study the spectrum of the associated (Perron-Frobenius) transfer operators. We give a FrCchet space on which the operator associated to the full system has a simple eigenvalue at 1 (corresponding to the SRB measure p* previously obtained by Bricmont-Kupiainen (BKl)) and the rest of the spectrum, except maybe for continuous spectrum, is inside a disc of radius smaller than one. For d = 1 we also construct Banach spaces of densities with respect to pr on which perturbation theory, applied to the diff…
Erstversorgung durch Rettungsassistenten und Rettungssanitäter bei kombinierten Einsätzen von RTW und NAW in einem stationären NAW-System
2003
OBJECTIVE: The present study was conducted to evaluate the quality of paramedic care and the feasibility and cost-effectiveness of sending a well-trained paramedic team to the sight of a medical emergency to initiate active medical treatment prior to the arrival of the mobile intensive care unit (MICU). METHODS: We examined 200 cases of medical treatment initiated by paramedics before arrival of the MICU team at the site of the medical emergency. Using a questionnaire, all emergency procedures performed by the paramedic team on scene were recorded and defined as "required", "carried out", and "accurately performed". The documented emergency procedures were divided into three categories: bas…
Hotspots of species richness, threat and endemism for terrestrial vertebrates in SW Europe
2011
The Mediterranean basin, and the Iberian Peninsula in particular, represent an outstanding “hotspot” of biological diversity with a long history of integration between natural ecosystems and human activities. Using deductive distribution models, and considering both Spain and Portugal, we downscaled traditional range maps for terrestrial vertebrates (amphibians, breeding birds, mammals and reptiles) to the finest possible resolution with the data at hand, and we identified hotspots based on three criteria: i) species richness; ii) vulnerability, and iii) endemism. We also provided a first evaluation of the conservation status of biodiversity hotspots based on these three criteria considerin…
Cell Systems Bioelectricity: How Different Intercellular Gap Junctions Could Regionalize a Multicellular Aggregate
2021
Simple Summary Electric potential patterns across tissues are instructive for development, regeneration, and tumorigenesis because they can influence transcription, migration, and differentiation through biochemical and biomechanical downstream processes. Determining the origins of the spatial domains of distinct potential, which in turn decide anatomical features such as limbs, eyes, brain, and heart, is critical to a mature understanding of how bioelectric signaling drives morphogenesis. We studied theoretically how connexin proteins with different voltage-gated gap junction conductances can maintain multicellular regions at distinct membrane potentials. We analyzed a minimal model that i…
A novel T-C3N and seawater desalination
2020
A structurally stable stacked multilayer carbonitride is predicted with the aid of ab initio calculations. This carbonitride consists of C3N tetrahedra, and is similar to T-carbon and thus named T-C3N. Its 2-dimensional (2D) monolayer is also carefully investigated in this work. The studies on electronic properties reveal that bulk and 2D T-C3N are insulators with a 5.542 eV indirect band gap and a 5.741 eV direct band gap, respectively. However, the monolayer T-C3N exhibits an excellent uniform porosity. Its 5.50 A pore size is perfect for water nanofiltration. The adsorption and permeation of water molecules on the monolayer T-C3N are investigated. Its promising potential application in h…
The half-metallic ferromagnet
2007
Abstract Electronic structure calculation were used to predict a new material for spintronic applications. Co 2 Mn 0.5 Fe 0.5 Si is one example which is stable against on-site correlation and disorder effects due to the position of the Fermi energy in the middle of the minority band gap. Experimentally the sample were made exhibiting L 2 1 structure and a high magnetic order.
Nanotexturing To Enhance Photoluminescent Response of Atomically Thin Indium Selenide with Highly Tunable Band Gap.
2016
Brotons-Gisbert, Mauro et al.
Investigations of the emission properties of single CdS-nanocrystallites
1997
Semiconductor nanocrystallites (NCs) with a radius in the range of the bulk exciton radius exhibit a strong quantum size effect. We investigated CdS-NCs, that were spin coated on a glass cover slip, with a low temperature confocal microscope. At low coverage we could image the fluorescence light from single NCs. The typical emission spectra of single NCs show four peaks. Besides the main peak related to near bandgap recombination, up to two LO-phonon satellites and one blue shifted peak were observed. It could be shown that the absorption can be polarization dependent. From the images as well as from the intensity autocorrelation function it could be concluded that the fluorescence emission…
Interfaces as design tools for the InAs/GaSb/InSb short-period superlattice for mid-infrared emission
2011
We use a standard 8 × 8 envelope-function approximation (EFA) formalism taking into account the effect of anisotropic and other interface (IF) interactions to investigate the electronic and optical properties of short-period superlattice laser structures (InAs/GaSb/InSb)×N grown on a GaSb substrate. We find that the band gaps numerically calculated at different temperatures give a good fitting with the experimental data confirming the model used. The calculated modal gain demonstrates that it is possible to achieve lasing operation at room temperature for N > 12 and for a reasonable total optical loss αt = 25 cm−1. Therefore, the 8 × 8 EFA formalism with IF design serves as a tool to model…
Band Gap Modeling of Different Ternary and Quaternary Alumina Garnet Phases Y3(AlXGa1-X)5O12 (YAGG) and Lu3(AlXGa1-X)5O12 (LuAGG). A Semiempirical Ap…
2022
A further generalization to quaternary oxide systems of the modeling equation of optical band gap values, based on the semiempirical correlation between the differences in the electronegativity of oxygen and the average cationic electronegativity, proposed some years ago, has been carried out by expanding the approach recently employed for ternary mixed oxides. The choice of oxide polymorphs and their influence on the fitting procedure of an experimental data set is evidenced by a detailed discussion of the fitting process of the literature's experimental band gap data pertaining two quaternary oxide systems of the garnet family, namely, Y3(AlxGa1-x)5O12 (YAGG) and Lu3(AlxGa1-x)5O12 (LuAGG)…