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Muséum d'histoire naturelle

Gastéropodes

Mermod, Gaston ; Piaget, Jean

Genève : Georg, 1930

(Catalogue des invertébrés de la Suisse ; fasc. 18)

Analyse: Description des mollusques gastéropodes présents en Suisse.

Public access from 1-ago-2019
Université de Neuchâtel

Ultra-low noise microwave generation with a free-running optical frequency comb transfer oscillator

Brochard, Pierre ; Schilt, Stéphane ; Südmeyer, Thomas

In: Optics Letters, 2018, vol. 43, no. 19, p. 4651-4654

We present ultra-low noise microwave synthesis by optical to radio-frequency (RF) division realized with a free-running or RF-locked optical frequency comb (OFC) acting as a transfer oscillator. The method does not require any optical lock of the OFC and circumvents the need for a high-bandwidth actuator. Instead, the OFC phase noise is electrically removed from a beat-note signal with an optical...

Université de Fribourg

Novel iron tweezers complexes for hydrogenation and polymerization of olefins

Mafua, Roger ; Jenny, Titus A. (Dir.)

Thèse de doctorat : Université de Fribourg, 2006 ; no. 1503.

The use of organometallic complexes as catalysts became a very significant topic in the field of material chemistry. However, despite of this development, only few of them contain iron(II), except the tridentate complex diimine pyridine developed by Gibson and Brookhart and employed in the olefin polymerization. Unfortunately, this model suffers by its lack of tolerance towards the minor changes...

Université de Fribourg

Truncating the memory time in nonequilibrium dynamical mean field theory calculations

Schüler, Michael ; Eckstein, Martin ; Werner, Philipp

In: Physical Review B, 2018, vol. 97, no. 24, p. 245129

The nonequilibrium Green's functions (NEGF) approach is a versatile theoretical tool, which allows to describe the electronic structure, spectroscopy, and dynamics of strongly correlated systems. The applicability of this method is, however, limited by its considerable computational cost. Due to the treatment of the full two-time dependence of the NEGF, the underlying equations of motion...

Université de Fribourg

Randomizing growing networks with a time-respecting null model

Ren, Zhuo-Ming ; Mariani, Manuel Sebastian ; Zhang, Yi-Cheng ; Medo, Matú?

In: Physical Review E, 2018, vol. 97, no. 5, p. 052311

Complex networks are often used to represent systems that are not static but grow with time: People make new friendships, new papers are published and refer to the existing ones, and so forth. To assess the statistical significance of measurements made on such networks, we propose a randomization methodology—a time- respecting null model—that preserves both the network's degree sequence...

Université de Fribourg

Revealing in-block nestedness: Detection and benchmarking

Solé-Ribalta, Albert ; Tessone, Claudio J. ; Mariani, Manuel S. ; Borge-Holthoefer, Javier

In: Physical Review E, 2018, vol. 97, no. 6, p. 062302

As new instances of nested organization—beyond ecological networks—are discovered, scholars are debating the coexistence of two apparently incompatible macroscale architectures: nestedness and modularity. The discussion is far from being solved, mainly for two reasons. First, nestedness and modularity appear to emerge from two contradictory dynamics, cooperation and competition. Second, ...

Université de Fribourg

Power enhancement via an ion-channel in a Raman free-electron laser

Huang, Xiaoli ; Zhang, Shi-Chang

In: Laser Physics, 2018, vol. 28, no. 9, p. 095002

As a high-power and high-efficiency coherent radiation source, the free-electron laser extends to two unique spectra: the region in the ultra-violet, x- and -rays, and the range in the millimeter- and terahertz-waves. Based on credible simulations, it is shown that the nonlinear power of a Raman free-electron laser in a millimeter wave range goes up and gets an increase of at least 9% when an...

Université de Fribourg

Colloidal fibers as structurant for worm-like micellar solutions

Zanchetta, Giuliano ; Mirzaagha, Shadi ; Guida, Vincenzo ; Zonfrilli, Fabio ; Caggioni, Marco ; Grizzuti, Nino ; Pasquino, Rossana ; Trappe, Veronique

In: Colloid and Polymer Science, 2018, vol. 296, no. 8, p. 1379–1385

We investigate the rheological properties of a simplified version of a liquid detergent composed of an aqueous solution of the linear alkylbenzene sulphonate (LAS) surfactant, in which a small amount of fibers made of hydrogenated castor oil (HCO) is dispersed. At the concentration typically used in detergents, LAS is in a worm-like micellar phase exhibiting a Maxwellian behavior. The...

Université de Fribourg

Metallic contact between MoS2 and Ni via Au nanoglue

Shi, Xinying ; Posysaev, Sergei ; Huttula, Marko ; Pankratov, Vladimir ; Hoszowska, Joanna ; Dousse, Jean?Claude ; Zeeshan, Faisal ; Niu, Yuran ; Zakharov, Alexei ; Li, Taohai ; Miroshnichenko, Olga ; Zhang, Meng ; Wang, Xiao ; Huang, Zhongjia ; Saukko, Sami ; González, Diego López ; Dijken, Sebastiaan van ; Alatalo, Matti ; Cao, Wei

In: Small, 2018, vol. 14, no. 22, p. 1704526

A critical factor for electronics based on inorganic layered crystals stems from the electrical contact mode between the semiconducting crystals and the metal counterparts in the electric circuit. Here, a materials tailoring strategy via nanocomposite decoration is carried out to reach metallic contact between MoS2 matrix and transition metal nanoparticles. Nickel nanoparticles (NiNPs) are ...