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Université de Fribourg

Mountain climates and climatic change: an overview of processes focusing on the european Alps

Beniston, Martin

In: Pure and Applied Geophysics, 2005, vol. 162(8-9), p. 1587

This contribution provides an overview of the intricacies of mountain climates, particularly as they pertain to the European Alps. Examples will be given of issues that are related to climatic change as observed in the Alps during the course of the 20th century, and some of the physical mechanisms that may be responsible for those changes. The discussion will then focus on the problems related to...

Université de Fribourg

Extreme climatic events: Examples from the alpine region

Beniston, Martin

In: Journal de Physique IV (Proceedings), 2004, vol. 121, p. 139

This paper provides a general overview of climatic extremes, how they may be defined and what they represent both in statistical and in physical terms, as well as the impacts they are capable of generating. A particular case study, namely the heat wave that affected many parts of Europe from June-August 2003, will be discussed in some detail. The final part of the paper will investigate, on the...

Université de Fribourg

The Alps - a barrier or a passage for ceramic trade ?

Maggetti, Marino

In: Archaeometry, 2005, vol. 47 (2), p. 389-401

The Alps as a barrier: ceramic remnants of the so-called Laugen-Melaun culture (c. 11th to c. sixth centuries bc) can be found in the northern Italy (Trentino/Alto Adige)—eastern Switzerland—Liechtenstein and western Austria region. A petrographic study of 454 sherds from this area covering a time span of 500 years reveals the following. (1) The pottery from the Trentino/Alto Adige contains a...

Université de Fribourg

Novel HEXOL-type cyclometallated iridium(III) complexes: stereoselective synthesis and structure elucidation

Yang, Liangru ; Zelewsky, Alexander von ; Stoeckli-Evans, Helen

In: Chemical Communications, 2005, vol. (33), p. 4155

Two diastereoisomers of tetranuclear cyclometallated iridium complexes, either having an inner core of HEXOL-type [Ir(IrCl₂)₃]⁶⁺ unit and a surface of six chiral, didentate, cyclometallated ligands, are stereoselectively synthesized from an enantiopure pinenopyridine derivative.

Université de Neuchâtel

Long-term elasticity in the continental lithosphere ; modelling the Aden Ridge propagation and the Anatolian extrusion process

Hubert-Ferrari, Aurélia ; Armijo, Rolando ; King, Geoffrey ; Manighetti, Isabelle ; Meyer, Bertrand ; Tapponnier, Paul

In: Geophysical Journal International, 2003, vol. 153, p. 111-132

The evolution of the Gulf of Aden and the Anatolian Fault systems are modelled using the principles of elastic fracture mechanics usually applied to smaller scale cracks or faults. The lithosphere is treated as a plate, and simple boundary conditions are applied that correspond to the known plate boundary geometry and slip vectors. The models provide a simple explanation for many observed...

Université de Fribourg

Higher-order response in [script O](N) by perturbed projection

Weber, Valéry ; Niklasson, Anders M. N. ; Challacombe, Matt

In: The Journal of Chemical Physics, 2005, vol. 123, p. 044106

Perturbed projection for linear scaling solution of the coupled-perturbed self-consistent-field equations [V. Weber, A.M.N. Niklasson, and M. Challacombe, Phys. Rev. Lett. 92, 193002 (2004)] is extended to the computation of higher-order static response properties. Although generally applicable, perturbed projection is further developed here in the context of the self-consistent first and second...

Université de Neuchâtel

Present-day geodynamics in the bend of the western and central Alps as constrained by earthquake analysis

Delacou, Bastien ; Burkhard, Martin ; Champagnac, Jean-Daniel ; Sue, Christian

In: Geophysical Journal International, 2004, vol. 158, p. 753-774

The contrasted tectonics of the western/central Alps is examined using a synthesis of 389 reliable focal mechanisms. The present-day strain regime is mapped and interpolated for the entire Alpine belt based on a newly developed method of regionalization. The most striking feature is a continuous area of extension which closely follows the large-scale topographic crest line of the Alpine arc....

Université de Fribourg

Is the vibrational optical activity of (R)-[²H₁, ²H₂, ²H₃]-neopentane measurable?

Hug, Werner ; Haesler, Jacques

In: International Journal of Quantum Chemistry, 2005, vol. 104(5), p. 695

The compound, (R)-[²H₁, ²H₂, ²H₃]-neopentane, with its Td symmetric electron distribution, is the archetype of molecules that owe their chirality exclusively to an asymmetric distribution of the masses of their nuclei. It has nine rotamers, which fall into two classes, one where the interchange of hydrogen and deuterium nuclei leads to an identical rotamer, and...

Université de Fribourg

Ab initio prediction of a multiferroic with large polarization and magnetization

Baettig, Pio ; Spaldin, Nicola A.

In: Applied Physics Letters, 2005, vol. 86, p. 012505

We describe the design of a magnetic ferroelectric with large spontaneous magnetization and polarization using first-principles density functional theory. The usual difficulties associated with the production of robustly insulating ferromagnets are circumvented by incorporating the magnetism through ferrimagnetic behavior. We show that the ordered perovskite Bi₂FeCrO₆ will have a...

Université de Fribourg

A test of the coevolution theory of autumn colours: colour preference of Rhopalosiphum padi on Prunus padus

Archetti, Marco ; Leather, Simon R.

In: Oikos, 2005, vol. 110(2), p. 339

According to the coevolution theory of autumn colours, the bright colours of trees evolved as a warning signal towards parasites colonizing the plant in autumn. We monitored colonization of the aphid Rhopalosiphum padi on individual tress of Prunus padus in autumn and observed a strong preference of aphids for trees with green leaves. This is the first direct observation of a key...