1,702 research outputs found
ENTWICKLUNG VON ABSCHEIDERGITTERN FÜR SCHIENENFAHRZEUGE MITTELS MODELLTECHNIK
Mittels Modelltechnik entwickelte Abscheidergitter für Schienenfahrzeuge, die in bezug
auf Abscheiderleistung und Energiebedarf dem konventionellen Düsenlüftungsgitter überlegen
sind. Wirkungsweise des Fliehkraft-Sendimentations-Abscheiders (FSA) und des konventionellen
Düsenlüftungsabscheiders (DLA) und deren entscheidende Einflußgröße für den Gesamtdruckverlust.
Universelle Arbeitsdiagramme ermöglichen eine Optimierung zwischen Abscheidegrad
und Energiabedarf des jeweiligen Abscheiders
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
Coupling/decoupling between translational and rotational dynamics in a supercooled molecular liquid
We use molecular dynamics computer simulations to investigate the
coupling/decoupling between translational and rotational dynamics in a
glass-forming liquid of dumbbells. This is done via a careful analysis of the
-relaxation time of the incoherent
center-of-mass density correlator at the structure factor peak, the
-relaxation time of the reorientational correlator, and the
translational () and rotational () diffusion constants. We find
that the coupling between the relaxation times and
increases with decreasing temperature , whereas the coupling
decreases between the diffusivities and . In addition, the
-dependence of decouples from that of , which is
consistent with previous experiments and has been interpreted as a signature of
the "translation-rotation decoupling." We trace back these apparently
contradicting observations to the dynamical heterogeneities in the system. We
show that the decreasing coupling in the diffusivities and is
only apparent due to the inadequacy of the concept of the rotational diffusion
constant for describing the reorientational dynamics in the supercooled state.
We also argue that the coupling between and
and the decoupling between and , both of which strengthen
upon cooling, can be consistently understood in terms of the growing dynamic
length scale.Comment: revised manuscript, to appear in Phys. Rev. Let
Psychiatrische Versorgungsepidemiologie
Zusammenfassung: Psychiatrische Versorgungsepidemiologie untersucht die Situation der Versorgung von Menschen mit psychischen Erkrankungen unter Alltagsbedingungen. Psychiatrische Versorgungsstrukturen in Deutschland haben sich in den letzten Jahrzehnten weg von stationärer Behandlung mit teilweise mehrmonatiger Aufenthaltsdauer hin zu dezentralen teilstationären und ambulanten Angeboten entwickelt. Derzeit hat sich die Verschiebung von Behandlungskapazitäten zwischen den Settings stabilisiert und der Schwerpunkt der Versorgungsplanung liegt mehr auf der Entwicklung von möglichst flächendeckenden Strukturen zur Vernetzung der oftmals noch fragmentierten und streng an den Sektorgrenzen orientierten Versorgungslandschaft. Der Versorgungsbedarf hängt mit einer Vielzahl Faktoren wie den epidemiologischen Daten der Bevölkerung, der Inanspruchnahme und den gesundheitspolitischen Rahmenbedingungen zusammen. Ob die derzeitigen Versorgungsstrukturen den aktuellen Bedarf abdecken und den Qualitätsansprüchen genügen, ist aufgrund der spärlichen Datenlage und dem Mangel an Referenzmaßstäben nur schwer zu beurteilen. Ein substanzieller Ausbau psychiatrischer Versorgungsforschung in den kommenden Jahren ist hierfür grundlegend erforderlic
Irreversibility on the Level of Single-Electron Tunneling
We present a low-temperature experimental test of the fluctuation theorem for
electron transport through a double quantum dot. The rare entropy-consuming
system trajectories are detected in the form of single charges flowing against
the source-drain bias by using time-resolved charge detection with a quantum
point contact. We find that these trajectories appear with a frequency that
agrees with the theoretical predictions even under strong nonequilibrium
conditions, when the finite bandwidth of the charge detection is taken into
account
Magnetic Miniband Structure and Quantum Oscillations in Lateral Semiconductor Superlattices
We present fully quantum-mechanical magnetotransport calculations for
short-period lateral superlattices with one-dimensional electrostatic
modulation. A non-perturbative treatment of both magnetic field and modulation
potential proves to be necessary to reproduce novel quantum oscillations in the
magnetoresistance found in recent experiments in the resistance component
parallel to the modulation potential. In addition, we predict oscillations of
opposite phase in the component perpendicular to the modulation not yet
observed experimentally. We show that the new oscillations originate from the
magnetic miniband structure in the regime of overlapping minibands.Comment: 6 pages with 4 figure
Local prediction of turning points of oscillating time series
For oscillating time series, the prediction is often focused on the turning
points. In order to predict the turning point magnitudes and times it is
proposed to form the state space reconstruction only from the turning points
and modify the local (nearest neighbor) model accordingly. The model on turning
points gives optimal prediction at a lower dimensional state space than the
optimal local model applied directly on the oscillating time series and is thus
computationally more efficient. Monte Carlo simulations on different
oscillating nonlinear systems showed that it gives better predictions of
turning points and this is confirmed also for the time series of annual
sunspots and total stress in a plastic deformation experiment.Comment: 7 pages, 5 figures, 2 tables, submitted to PR
- …