Femtosekunden-Photoelektronenspektroskopie an isolierten Multianionen

The ultrafast excited state dynamics and electronic structure of molecular multianions are studied via femtosecond time-resolved photoelectron spectroscopy in gas phase. Investigations on isolated molecules give direct access to intrinsic photophysical properties fading out any disturbing influences of the local environment - with remarkable effects for multiply charged species. Excited state electron tunneling detachment is highlighted as a unique pathway in the photophysics of multianions

Highly efficient soft x-ray spectrometer for transient absorption spectroscopy with broadband table-top high harmonic sources

We present a novel soft x-ray spectrometer for ultrafast absorption spectroscopy utilizing table-top femtosecond high-order harmonic sources. Where most commercially available spectrometers rely on spherical variable line space gratings with a typical efficiency on the order of 3% in the first diffractive order, this spectrometer, based on a Hettrick–Underwood design, includes a reflective zone plate as a dispersive element. An improved efficiency of 12% at the N K-edge is achieved, accompanied by a resolving power of 890. The high performance of the soft x-ray spectrometer is further demonstrated by comparing nitrogen K-edge absorption spectra from calcium nitrate in aqueous solution obtained with our high-order harmonic source to previous measurements performed at the electron storage ring facility BESSY II

Observations of Ultraluminous Infrared Galaxies with the Infrared Spectrograph on the Spitzer Space Telescope: Early Results on Mrk 1014, Mrk 463, and UGC 5101

We present spectra taken with the Infrared Spectrograph on Spitzer covering the 5-38micron region of three Ultraluminous Infrared Galaxies (ULIRGs): Mrk 1014 (z=0.163), and Mrk 463 (z=0.051), and UGC 5101 (z=0.039). The continua of UGC 5101 and Mrk 463 show strong silicate absorption suggesting significant optical depths to the nuclei at 10microns. UGC 5101 also shows the clear presence of water ice in absorption. PAH emission features are seen in both Mrk 1014 and UGC 5101, including the 16.4micron line in UGC 5101. The fine structure lines are consistent with dominant AGN power sources in both Mrk 1014 and Mrk 463. In UGC 5101 we detect the [NeV] 14.3micron emission line providing the first direct evidence for a buried AGN in the mid-infrared. The detection of the 9.66micron and 17.03micron H$_{2}$ emission lines in both UGC 5101 and Mrk 463 suggest that the warm molecular gas accounts for 22% and 48% of the total molecular gas masses in these galaxies.Comment: Accepted in ApJ Sup. Spitzer Special Issue, 4 pages, 3 figure

On-orbit performance of the MIPS instrument

The Multiband Imaging Photometer for Spitzer (MIPS) provides long wavelength capability for the mission, in imaging bands at 24, 70, and 160 microns and measurements of spectral energy distributions between 52 and 100 microns at a spectral resolution of about 7%. By using true detector arrays in each band, it provides both critical sampling of the Spitzer point spread function and relatively large imaging fields of view, allowing for substantial advances in sensitivity, angular resolution, and efficiency of areal coverage compared with previous space far-infrared capabilities. The Si:As BIB 24 micron array has excellent photometric properties, and measurements with rms relative errors of 1% or better can be obtained. The two longer wavelength arrays use Ge:Ga detectors with poor photometric stability. However, the use of 1.) a scan mirror to modulate the signals rapidly on these arrays, 2.) a system of on-board stimulators used for a relative calibration approximately every two minutes, and 3.) specialized reduction software result in good photometry with these arrays also, with rms relative errors of less than 10%

Rapport IV.10. Agglomération lyonnaise : utilisation des retenues de la «Zone des Loisirs » de l'Ile de Miribel-Jonage

Two arms of the river Rhone just above Lyons, the Miribel and Jonage Canals, form an island of several thousand hectares, which is under water during the river’s periodic floods. Very little was known about the hydrological features of this site, despite its proximity to the City until 1962, when a systematic survey of it was begun. This was based on a statistical study of passing floods and their hydraulic characteristics to begin with and the came to consider a preliminary scheme for the “ reclamation ” of the Miribel-Jonage island, which is considered particularly a valuable town-planning asset because of its proximity to Lyons. Two ideas considered were, first,, to backfill the flood plain or dyke the island so as to keep it above water, and second, a controlled submersion scheme to create the kina of recreational lakes needed to meet cm increasing demand for convenient waterside and boating amenities near the city. The studies for the submersion scheme are described, also the broad outlines of a Recreational Zone based on lakes in the form of a series of reservoirs controlled by submersible weirs and gated sluiceways, and model tests of various hydraulic designs calculated to cost least to implement whilst improving flood passage conditions through the city. This last point proved to be highlight of the study, for it showed a way of attenuating the hundred-year flood by 20 centimetres or so by off-season draining of all or part of the lakes. Moreover, by providing a storage capacity of some 50 million cubic metres, this scheme would also substantially reduce the risk of riverside cellars in Lyons and low-lying parts of the harbour area used as car parks being submerged during moderate river floods.Deux bras du Rhône à l’amont immédiat de Lyon, le Canal de Miribel et le Canal de Jonage, forment une île assez vaste, de plusieurs milliers d’hectares, vouée pour sa plus grande partie au passage périodique des crues du grand fleuve alpin. Ce site du Rhône, dont l’hydrologie était peu connue, aux portes pourtant de l’agglomération lyonnaise, a fait l’objet depuis 1962 d’une étude systématique, d’abord basée sur l’étude statistique du passage des crues et de leurs caractéristiques hydrauliques, puis sur l’avant-projet de «récupération » de File de Miribel-Jonage dont la proximité du tissu urbain lyonnais offre un intérêt tout particulier d’ordre urbanistique : cette récupération a été successivement envisagée par une «mise hors d’eau » par endiguement ou remblaiement du lit majeur, puis, a l’opposé, par une «mise en eau » judicieuse permettant la création de plans d’eau plaisanciers dont l’intérêt naît d’une proximité urbaine qui exercera de plus en plus une forte demande en loisirs liés à l’eau. On trouvera, dans l’exposé, la relation des études concernant la «mise en eau » : description des grandes lignes d’un projet de Zone de Loisirs à base de plans d’eau formant des retenues successives réglées, derrière déversoirs submersibles, par des pertuis munis de consigne, et test sur modèle de diverses solutions hydrauliques propres à entraîner les travaux les plus économiques en améliorant, si possible, le passage des crues dans Lyon. C’est sur ce dernier point, que l’étude s’est révélée la plus originale, fournissant la possibilité d ’écrêter d’une vingtaine de centimètres la crue centenaire en vidangeant hors saison de plaisance tout ou partie des plans d’eau de loisirs ; cette vidange permet également, avec une tranche de rétention de l’ordre de 50 millions de m3, une amélioration appréciable de l’incidence des crues moyennes sur le noyage des caves lyonnaises riveraines ou des bas-ports du Rhône dans Lyon à usage de parking.Winghart Jean. Rapport IV.10. Agglomération lyonnaise : utilisation des retenues de la «Zone des Loisirs » de l'Ile de Miribel-Jonage. In: La prévision des crues et la protection contre les inondations. Dixièmes journées de l'hydraulique. Paris, 5, 6 et 7 juin 1968. Tome 4, 1969

Haut-Rhône à l'amont de Lyon : étude hydraulique de l'ile de Miribel-Jonage

Two arms of the Rhône above Lyons form the Miribel and Jonage canals (connected with the Electricité de France power scheme at Cusset), with an 18 km long by 2-5 km wide island between them, which very readily floods at the present time, though the highest flow velocities concentrate in the Miriel canal and an old arm of the river, the "Vieux Rhône". During the latter half of the last century, the Miribel canal underwent a drastic change in its hydraulic conditions, due to the concentrated solids in the water it carried, with the result that today, the downstream part of this canal has taken the form of an alluvial cone with a substantial gravel bank whose stability it is most important to preserve. Possible ways of putting part or the whole of the Miribel-Jonage island permanently above water are either by extensive dyking, or by deepening the Miribel canal downstream from a drop structure, though provided neither navigability of the Jonage canal nor the downstream part of the Miribel canal are affected and this part of the river does not lose any of its present sediment- conveying capacity. With such a scheme, considerable areas could be cleared in the immediate vicinity of the city as building land or for extensive artificial lakes for its population. In view of the proximity of this built-up area of over one million inhabitants, it was most important to check that the proposed reclamation work would not adversely affect the following : (i) The highest flood discharge level through Lyons ; (ii) The rate of arrivaI of the flood peak (i.e. acceleration due to removal of part of the island, and hence some of its attenuating action). In answer to a request by the Rhône and Saône Navigation Section of the 'Ponts et Chaussées' Administration, the Chatou Hydraulics Laboratory studied the flow of the 1957 flood past the Miribel-Jonage island on a mathematical model working on the Barré de Saint-Venant equation. This model successfully cleared up the previously obscure question of how the flood flow divides between the Miribel canal, the 'Vieux Rhône', the Tonage canal and the flood plain as a whole. From its simplified initial stage with steady flow, the mathematical model stndy was then carried further with varying flow conditions representative of the flood flows. The results of this study are most promissing, as they show partial raising of the island to be feasible wilhout any adverse effects