A 20 cm2 CCD mosaic camera for a dark matter search part I : Mechanics,optics and cryogeny     

Arnaud  M.  Aubourg  E.  Bareyre  P.  Br';ehin  S.  Caridroit  R.  de Kat  J.  Dispau  G.  Djidi  K.  Gros  M.  Lachièze-Rey  M.  Laigneau  Y.  Laurent  B.  Lesquoy  E.  Lavocat  Ph.  Magneville  C.  Mazeau  B.  Milsztajn  A.  Moscoso  L.  Pasquaud  J.  Paul  B.  Perrin  P.  Petibon  J.  Piret  Y.  Queinnec  F.  Rich  J.  Spiro  M.  de Trogoff  J.  Vigroux  L.  Zylberajch  S.  Ansari  R.  Cavalier  F.  Moniez  M.  Beaulieu  J. P.  Ferlet  R.  Grison  Ph.  Vidal-Madjar  A.  Adrianzyk  G.  Berger  J. P.  Burnage  R.  Delclite  J. C.  Kohler  D.  Magnan  R.  Richaud  A.  Guibert  J.  Moreau  O.  Tajahmady  F.  Baranne  A.  Maurice  E.  Prévôt  L.  Gry  C. 《Experimental Astronomy》1994,4(3-4):265-278

A 20cm ² CCD mosaic camera has been especially built to search for dark galactic halo objects by the gravitational microlensing effect. The sensitive area is made of 16 edge-buttable CCDs developped by Thomson-CTS, with 23×23 µm ² pixels. The 35 kg camera housing and mechanical equipment is presented. The associated electronics and data acquisition system are described in a separate paper. The camera resides at the focal plane of a 40 cm, f/10, Ferson reflector. The instrument has been in operation since December 1991 at the La Silla Observatory (ESO).  相似文献   

Mono- and dicyclic unsaturated triterpenoid hydrocarbons in sediments from Lake Masoko (Tanzania) widely extend the botryococcene family     

Romain de Mesmay  Pierre Metzger  Vincent Grossi  Sylvie Derenne 《Organic Geochemistry》2008,39(7):879-893

A mixture of C₃₃–C₃₇ botryococcenes and partially reduced derivatives was isolated from ca. 32,000 year old sediment from Lake Masoko, a freshwater crater lake in the Rungwe Range area (Tanzania). Botryococcenes and derivatives accounted for 246 μg/g dry sediment and for >92% of the hydrocarbon fraction; 1D and 2D nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry allowed the structure of the dominant botryococcene (43% of hydrocarbon fraction) to be established, after purification using high performance liquid chromatography (HPLC). The compound is a novel tetraunsaturated dicyclic C₃₄ botryococcene and is named C₃₄ masokocene. Overall, the structures of six other novel botryococcenes and four partially reduced derivatives were tentatively assigned. The structures of the new biomarkers, three dicyclic C₃₄–C₃₆ botryococcenes (or masokocenes) and seven monocyclic C₃₄–C₃₇ analogues are discussed along with their biosynthetic relationship. The high abundance of such polyunsaturated compounds preserved in 32,000 year old sediment from the lake indicates an aquatic ecosystem dominated at the time by the green alga Botryococcus braunii, as well very good preservation of the organic matter.  相似文献   

Rivers, chemical weathering and Earth's climate   总被引：4，自引：0，他引：4  

Bernard Dupr  Cline Dessert  Priscia Oliva  Yves Goddris  Jrme Viers  Louis Franois  Romain Millot  Jrme Gaillardet 《Comptes Rendus Geoscience》2003,335(16):1141-1160

We detail the results of recent studies describing and quantifying the large-scale chemical weathering of the main types of continental silicate rocks: granites and basalts. These studies aim at establishing chemical weathering laws for these two lithologies, describing the dependence of chemical weathering on environmental parameters, such as climate and mechanical erosion. As shown within this contribution, such mathematical laws are of primary importance for numerical models calculating the evolution of the partial pressure of atmospheric CO₂ and the Earth climate at geological timescales. The major results can be summarized as follow: (1) weathering of continental basaltic lithologies accounts for about 30% of the total consumption of atmospheric CO₂ through weathering of continental silicate rocks. This is related to their high weatherability (about eight times greater than the granite weatherability); (2) a simple weathering law has been established for basaltic lithologies, giving the consumption of atmospheric CO₂ as a function of regional continental runoff, and mean annual regional temperature; (3) no such simple weathering law can be proposed for granitic lithologies, since the effect of temperature can only be identified for regions displaying high continental runoff; (4) a general law relating mechanical erosion and chemical weathering has been validated on small and large catchments. The consequences of these major advances on the climatic evolution of the Earth are discussed. Particularly, the impacts of the onset of the Deccan trapps and the Himalayan orogeny on the global carbon cycle are reinvestigated. To cite this article: B. Dupré et al., C. R. Geoscience 335 (2003).  相似文献   

A Comparison of Various Methods for the Numerical Evaluation of Porous Media Permeability Tensors from Pore-Scale Geometry     

Romain Guibert  Pierre Horgue  Gérald Debenest  Michel Quintard 《Mathematical Geosciences》2016,48(3):329-347

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Correction to: Future changes in Atlantic hurricanes with the rotated-stretched ARPEGE-Climat at very high resolution     

Chauvin  Fabrice  Pilon  Romain  Palany  Philippe  Belmadani  Ali 《Climate Dynamics》2021,56(1):683-685

Climate Dynamics - The original article can be found online.  相似文献   

High-resolution rainfall variability simulated by the WRF RCM: application to eastern France     

Romain Marteau  Yves Richard  Benjamin Pohl  Carmela Chateau Smith  Thierry Castel 《Climate Dynamics》2015,44(3-4):1093-1107

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Review: Theory-guided machine learning applied to hydrogeology—state of the art,opportunities and future challenges     

Adombi  Adoubi Vincent De Paul  Chesnaux  Romain  Boucher  Marie-Am&#;lie 《Hydrogeology Journal》2021,29(8):2671-2683

Hydrogeology Journal - Thanks to recent technological advances, hydrogeologists now have access to large amounts of data acquired in real time. Processing these data using traditional modelling...  相似文献   

Stress changes induced at neighbouring faults by the June 2000 earthquakes,South Iceland Seismic Zone     

Romain Plateaux  Jacques Angelier  Françoise Bergerat  Frederic Cappa  Ragnar Stefánsson 《地学学报》2010,22(2):79-86

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Discovery of High Proper-Motion Ancient White Dwarfs: Nearby Massive Compact Halo Objects?     

Ibata R  Irwin M  Bienaymé O  Scholz R  Guibert J 《The Astrophysical journal》2000,532(1):L41-L45

We present the discovery and spectroscopic identification of two very high proper-motion ancient white dwarf stars, found in a systematic proper-motion survey. Their kinematics and apparent magnitude clearly indicate that they are halo members, while their optical spectra are almost identical to the recently identified cool halo white dwarf WD 0346+246. Canonical stellar halo models predict a white dwarf volume density that is 2 orders of magnitude less than the rho approximately 7x10-4 M middle dot in circle pc-3 inferred from this survey. With the caveat that the sample size is very small, it appears that a significant fraction, approximately 10%, of the local dark matter halo is in the form of very old, cool, white dwarfs.  相似文献   

A 20cm 2 CCD mosaic camera for a dark matter search part II : Electronics,data acquisition and performance     

Arnaud  M.  Aubourg  E.  Bareyre  P.  Br';ehin  S.  Caridroit  R.  de Kat  J.  Dispau  G.  Djidi  K.  Gros  M.  Lachièze-Rey  M.  Laigneau  Y.  Laurent  B.  Lesquoy  E.  Lavocat  Ph.  Magneville  C.  Mazeau  B.  Milsztajn  A.  Moscoso  L.  Pasquaud  J.  Paul  B.  Perrin  P.  Petibon  J.  Piret  Y.  Queinnec  F.  Rich  J.  Spiro  M.  de Trogoff  J.  Vigroux  L.  Zylberajch  S.  Ansari  R.  Cavalier  F.  Moniez  M.  Beaulieu  J. P.  Ferlet  R.  Grison  Ph.  Vidal-Madjar  A.  Adrianzyk  G.  Berger  J. P.  Burnage  R.  Delclite  J. C.  Kohler  D.  Magnan  R.  Richaud  A.  Guibert  J.  Moreau  O.  Tajahmady  F.  Baranne  A.  Maurice  E.  Prévôt  L.  Gry  C. 《Experimental Astronomy》1994,4(3-4):279-296

Conclusion To summarize, the readout and the control system of the CCD mosaic camera are running since December 1991 at the La Silla Observatory (ESO). The overall performance of the camera has been good. About 12000 pictures (data and flat-fields) have been successfully registered up to now. We will report in the near future preliminary scientific results of the EROS experiment.  相似文献