Concept

Réflexion (mathématiques)

Publications associées (125)

The luminescence of NaxEu3+(2−x)/3MoO4 scheelites depends on the number of Eu-clusters occurring in their incommensurately modulated structure

Gervais Chapuis, Jean-Claude Bünzli, Alla Arakcheeva, Philip Pattison, Svetlana Eliseeva, Dmitry Logvinovich

Scheelite related compounds with general formula Mn(XO4)m are of interest owing to their optical properties, stability and relatively simple preparation. Eu3+-containing scheelites are considered as red emitting phosphors and the main factors affecting the ...

2012

Uncoupled photonic band gaps

We theoretically investigated the symmetry properties of the modes in two-dimensional square lattice photonic crystals in order to study phenomena that would enable new frontiers in the applications of photonic crystals. Using group theory, symmetry analys ...

Elsevier Science Bv2012

The effect of figural manipulations on brightness differences in the Benary cross

Marcus Leonardus Vergeer

The Benary cross is a classical demonstration showing that the perceived brightness of an area is not solely determined by its luminance, but also by the context in which it is embedded. Despite the fact that two identical grey triangles are flanked by an ...

Pion2011

Overview of toroidal momentum transport

Basil Duval, Yann Camenen, Alessandro Bortolon, Giovanni Tardini

Toroidal momentum transport mechanisms are reviewed and put in a broader perspective. The generation of a finite momentum flux is closely related to the breaking of symmetry (parity) along the field. The symmetry argument allows for the systematic identifi ...

2011

Overview of toroidal momentum transport

Basil Duval, Yann Camenen, Alessandro Bortolon, Lucia Isabel Federspiel, Giovanni Tardini

2011

Ag-coverage-dependent symmetry of the electronic states of the Pt(111)-Ag-Bi interface: The ARPES view of a structural transition

Klaus Kern, Harald Brune, Marco Grioni, Alberto Crepaldi, Emmanouil Frantzeskakis

We studied by angle-resolved photoelectron spectroscopy the strain-related structural transition from a pseudomorphic monolayer (ML) to a striped incommensurate phase in an Ag thin film grown on Pt(111). We exploited the surfactant properties of Bi to grow ...

2011

Influence of Subsurface Layers on the Adsorption of Large Organic Molecules on Close-Packed Metal Surfaces

Klaus Kern

The asymmetric molecule 4-[trans-2-(pyrid-4-yl-vinyl)] benzoic acid (PVBA) adsorbed on Cu(111) is characterized by scanning tunneling microscopy (STM) and density functional theory (DFT) to determine the influence of subsurface atomic layers on the adsorpt ...

2011

Dynamics of Urban Centre and Concepts of Symmetry: Centroid and Weighted Mean

Jong-Jin Park

The city is a kind of complex system being capable of auto-organization of its programs and adapts a principle of economy in its form generating process. A new concept of dynamic centre in urban system, called "the programmatic moving centre", can be used ...

Birkhäuser-Verlag, Springer2011

The role of the tangent bundle for symmetry operations and modulated structures

Gervais Chapuis, Kurt Schenk, Philippe Kocian

An equivalence relation on the tangent bundle of a manifold is defined in order to extend a structure (modulated or not) onto it. This extension affords a representation of a structure in any tangent space and that in another tangent space can easily be de ...

2010

Maximal symmetrization and reduction of fields: Application to wave functions in solid-state nanostructures

Marc-André Dupertuis, Sascha Dalessi

A general formalism for the maximal symmetrization and reduction of fields (MSRFs) is proposed and applied to wave functions in solid-state nanostructures. Its primary target is to provide an essential tool for the study and analysis of the electronic and ...

2010

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