Nonequilibrium expressions for entropy and other thermodynamic quantities

The entropy is written as a density series expansion involving a new kind of cumulant. These are defined as usual from the so-called reduced distribution functions. The first four terms of the series expansion of the entropy are shown to be identical to the known result. When density corrections are retained up to theuth order, the entropy is proved to obey approximately a conservation theorem. Finally, a discussion of nonequilibrium and equilibrium properties of the grand canonical ensemble is presented.     

Brechungs-index-Inkremente von gel?sten Polymeren: Untersuchung des Mischungsgesetzes. Einflu? des Molekulargewichtes und der Struktur

Ohne Zusammenfassung     

Electronic effect and elastic properties of RbH2PO4 crystals

We have studied the dielectric, elastic piezoelectric properties, and the electrocaloric effect of a single crystal of RbH₂PO₄. If RbDP undergoes a first order transition, the temperature range must be small and a small field can change it to a second order one.     

From micro to nano reentrant structures: hysteresis on superomniphobic surfaces

The paper reports on the wetting characterization of two surfaces presenting reentrant shapes at micro- and nanoscale using low surface tension liquids (down to 28 mN/m). On the one hand, mushroom-like microstructures are fabricated by molding poly(dimethylsiloxane) (PDMS) onto a patterned sacrificial photoresist bilayer. On the other hand, zinc oxide nanostructures (ZnO NS) are synthesized by easy and fast chemical bath deposition technique. The PDMS and ZnO NS surfaces are then chemically modified with 1H,1H,2H,2H-perfluorodecyltrichlorosilane in vapor phase. Both PDMS and ZnO NS surfaces exhibit a large apparent contact angle (>150°) and contact angle hysteresis varying from 50° to a quasi-null value. This large discrepancy can be ascribed to the length scale and topography of the structures, promoting either a vertical imbibition or a lateral spreading within the roughness.     

Plasmon resonance in sputtered gold films observed in scanning tunneling microscopy

Gold films grown on BaTiO₃ substrates, illuminated by a monochromatic beam in the visible range, were investigated using scanning tunneling microscopy (STM). Irregular variations in the tip displacements versus photon energy are observed at energies of the surface plasmon resonances (2.0 ± 0.1 and 2.7 ± 0.1 eV) of the rough gold film.     

Dynamic resolution of N-alkyl-2-lithiopyrrolidines with the chiral ligand (−)-sparteine

A selection of 2-lithiopyrrolidines with different N-alkyl-substituents were prepared and tested for their dynamic resolution in the presence of the chiral ligand (−)-sparteine. Good yields of the electrophile-quenched products were obtained with enantiomer ratios up to 85:15 using branched N-alkyl derivatives. The major product was shown to have the opposite absolute configuration compared with that obtained in the asymmetric deprotonation of N-Boc-pyrrolidine with (−)-sparteine. The enantioselectivity arises from a dynamic thermodynamic resolution in which the minor diastereomeric complex reacts faster with the electrophile.     

Polarized neutron reflection study of an Er/Fe multilayer

Low angle polarized neutron scattering experiments have been performed on an Er91 Å/Fe39 Å multilayer. The evolution of the intensity of the first peak with the temperature and the external magnetic field shows that the average magnetizations of Fe and Er layers are in the applied field direction. The study of the intensities of the second and the third peaks indicates that there is an interface effect: some erbium atoms remain antiferromagnetically coupled to iron at the interface.     

Advanced simulations of spectroscopic signatures of charge exchange in laser-produced plasmas

We present an advanced theory of charge-exchange-caused dips (also called X-dips) in spectral lines from laser-produced plasmas. We compare predictions of this advanced theory with our previously published experimental results where, in the process of a laser irradiation of targets made out of aluminum carbide, we observed two X-dips in the L _γ line of Al XIII perturbed by fully stripped carbon. We show that our advanced theory is in excellent agreement with our experimental results. From the practical point of view, our results open up a way to experimentally produce not-yet-available fundamental data on charge exchange between multicharged ions, virtually inaccessible by other experimental methods. From the theoretical viewpoint, the results are important because the X-dips are the only one signature of charge exchange in profiles of spectral lines emitted by plasmas and they are the only one quasimolecular phenomenon that could be observed at relatively “low” densities of laser-produced plasmas. Received 25 March 2002 Published online 19 July 2002     

Synthèse d'amines hétérocycliques,cancérostatiques potentiels

We report the nitration of various heterocycles containing two heterocyclic nitrogen atoms. The amines obtained by reduction have been characterized and the fact that the amines have been tested for anticancer activity is also reported.