A Ru(terpy)(phen)-incorporating ring and its light-induced geometrical changes

A Ru(terpy)(phen) motif has been inscribed in a 39-membered ring by functionalizing the ligands and subsequently performing a cyclization reaction on the complex; by visible light irradiation, a dramatic geometrical changeover of the cyclic complex takes place which can be reversed thermally.     

Jamin Fabry-Perot interferometer

A novel type of interferometer was designed and tested experimentally. It combines the advantages of the spatial path separation used in the two-wave polarized Jamin interferometer and the high sensitivity that characterizes the multiwave Fabry-Perot interferometer. Furthermore, when it is sandwiched between crossed polarizers it shows a sensitivity to intracavity anisotropies that is proportional to the square of the Fabry-Perot interferometer's finesse.     

Bortrifluorid-katalysierte,ohne Schwermetallzusätze verlaufende Hydratisierung von Alkinen

Acetylenes are hydrated in benzene-acetonitrile mixtures in the presence of phosphoric acid saturated with boron trifluoride and in the absence of heavy metal ions to the corresponding ketones in high yields.     

Study of the hydrogen solid solution in thulium

Solid solutions of hydrogen in thulium are investigated, mainly by X-ray determinations in the temperature range 20–500°C. Several observations lead us to distinguish between two variaties α and α¹. In the range of existence of the α¹ phase, below the transition temperature of 120°C, the hydrogen interstitials induce in the metal lattice a behaviour different from that of the α phase, as concerns the phase equilibrium, the additional resistivity, and the lattice anisotropy.Several simple models are proposed for the explanation of this anomaly, encountered also in other heavy rate earth-hydrogen systems.     

A limiting absorption principle for scattering problems with unbounded obstacles

A generalized mode matching method that applies to a wide class of scattering problems is developed in the time harmonic two‐dimensional Helmholtz case. This method leads by variational means to an integro‐differential formulation whose unknown is the trace of the field on an unbounded one‐dimensional interface. The well‐posedness is proved after a careful study of the rather original functional framework. Owing to a fundamental density result—based upon some properties of a singular integral operator similar to the Hilbert transform—the limiting absorption principle related to this original formulation is established. Finally, two other situations are emphasized. Copyright © 2001 John Wiley & Sons, Ltd.     

Turbulent kinetic energy balance in a LEBU modified turbulent boundary layer

An experimental study of the turbulent kinetic energy balance is performed in a LEBU manipulated turbulent boundary layer. The estimation of almost all the terms of the k-equation is obtained by hot wire anemometry. Near the manipulating device, strong alterations are observed, when compared with the natural conditions. The wake of the manipulator imposes two distinct zones. The lower part is characterized by negligible production compensated by diffusion, while, in the outer part, a large excess of production is balanced by diffusion and dissipation. The excess of dissipation rapidly vanishes downstream. The relaxation process is slower for production and diffusion.A version of this paper was presented at the 11th Symposium on Turbulence, University of Missouri-Rolla, Oct. 17–19, 1988     

Nanozeolite‐LTL with GdIII Deposited in the Large and EuIII in the Small Cavities as a Magnetic Resonance Optical Imaging Probe

The immense structural diversity of more than 200 known zeolites is the basis for the wide variety of applications of these fascinating materials ranging from catalysis and molecular filtration to agricultural uses. Despite this versatility, the potential of zeolites in medical imaging has not yet been much exploited. In this work a novel strategy is presented to selectively deposit different ions into distinct framework locations of zeolite‐LTL (Linde type L) and it is demonstrated that the carefully ion‐exchanged Gd/Eu‐containing nanocrystals acquire exceptional magnetic properties in combination with enhanced luminescence. This smart exploitation of the framework structure yields the highest relaxivity density (13.7 s^?1 L g^?1 at 60 MHz and 25 °C) reported so far for alumosilicates, rendering these materials promising candidates for the design of dual magnetic resonance/optical imaging probes, as demonstrated in preliminary phantom studies.     

Observational cosmology within the ESA science programme

Summary Several missions of the Science Programme of ESA aim at tackling issues of direct relevance to fundamental questions of modern cosmology. In this paper we are following the arrow of time on a simplified space-time diagram on which we identify the means of observing back in the past the physical phenomena or the structures which occur or appear at various epochs in the evolution of the Universe. We show how ESA through its science missions can contribute to these observations in a unique way. The missions themselves are not described in detail but we give in the text the relevant bibliographical references. To speed up publication, the proofs were not sent to the authors and were supervised by the Scientific Committee