Ab initio many-body calculation of excitons in solid Ne and Ar

Absorption spectra, exciton energy levels and wave functions for solid Ne and Ar have been calculated from first principles using many-body techniques. Electronic band structures of Ne and Ar were calculated using the GW approximation. Exciton states were calculated by diagonalizing an exciton Hamiltonian derived from the particle-hole Green function, whose equation of motion is the Bethe-Salpeter equation. Singlet and triplet exciton series up to n=5 for Ne and n=3 for Ar were obtained. Binding energies and longitudinal-transverse splittings of n=1 excitons are in excellent agreement with experiment. Plots of correlated electron-hole wave functions show that the electron-hole complex is delocalised over roughly 7 a.u. in solid Ar.Comment: 6 page

Nearest neighbor embedding with different time delays

A nearest neighbor based selection of time delays for phase space reconstruction is proposed and compared to the standard use of time delayed mutual information. The possibility of using different time delays for consecutive dimensions is considered. A case study of numerically generated solutions of the Lorenz system is used for illustration. The effect of contamination with various levels of additive Gaussian white noise is discussed.Comment: 4 pages, 5 figures, updated to final versio

Soziophysiologie: Grundlegende Prozesse der Emphathiefähigkeit

Diese Übersicht beschreibt Prozesse, welche dem komplexen Phänomen der menschlichen Empathie zugrunde liegen. Automatische, reflexartige Prozesse wie physiologische Ansteckung und Handlungsspiegelung werden über das Spiegelneuronensystem vermittelt und stellen eine Grundlage für die Weiterverarbeitung sozialer Signale dar. Im sozialen Kontakt entsteht damit auf der körperlichen Ebene eine direkte Verbindung zweier Individuen. Diese Verbindung besteht auf der gleichzeitigen Aktivierung gemeinsamer motorischer Repräsentationen. Auf implizite Art werden die so geteilten Eindrücke durch individuelle Assoziationen im limbischen und vegetativen System zu einem affektiven Zustand. Die hier beschriebenen Prozesse werden Soziophysiologie genannt. Durch kontrolliert-reflektierende, selbst-referentielle, d.h. auf die persönliche Innenwelt gerichtete (Weiter-)Verarbeitung solcher sozialen Signale, entstehen schliesslich explizite Repräsentationen des Bewusstseins von Anderen. Diese höhergradigen Prozesse nennen wir soziale Kognition. Durch das Zusammenspiel der verschiedenen Prozesse entsteht das Phänomen der menschlichen Empathiefähigkeit

Sorption, Desorption and Exchange of Cesium on Glaciofluvial Deposits

Distribution ratios and isotherms for Sorption, desorption and isotope-exchange of cesium (labelled with Cs-137) were measured on grain size fractions (<2mm) of quatemary glaciofluvial deposits. Sediment materials from two locations within Switzerland and synthetic groundwaters of different compositions were used. The investigated concentration range for cesium was 10"" — 10"' M. Cesium introduced into the system with the solid phase may influence the measurements at the lowest concentrations. Depending on the experimental conditions, the distribution ratios vary between 3 and 30'000 ml/g. The isotherms are non-linear. Normalization of the cesium concentration in the solid with the cation-exchange capacity leads to nearly identical isotherms for all size fractions of the two geographic locations. Desorption and exchange are retarded at the higher cesium concentrations. This can be explained by structural changes in clay minerals which dominate the Sorption of cesium on this material. Variations in the composition of the groundwater influence the Sorption of cesium only sHghtly; potassium and hydrogen ions are the main competitors