Counts, Sizes and Colours of Faint Infrared-Selected Galaxies     

Paolo Saracco  Sandro D'Odorico  Alan Moorwood  Jean G. Cuby 《Astrophysics and Space Science》2001,276(2-4):991-998

Deep J- and K _s-band images covering a 5 × 5 arcmin area centred on the NTT Deep Field have been obtained during the Science Verification of SOFI at the NTT. These images were made available via the Web in early June, 1998. The preliminary results we have obtained by the analysis of these data are the following: (i) the counts continue to rise with no evidence of a turnover or of a flattening down to the limits of the survey (K _s = 22.5 and J = 24 mag); (ii) we find a slope d log(N)/dm≈ 0.37, in agreement with most of the faintest surveys but much steeper than the Hawaii survey; (iii) fainter than K _s ≈ 19and J ≈ 20 mag, the median J-K colour of galaxies shows a break in its reddening trend turning toward bluer colours; (iv) faint bluer galaxies also display a larger compactness index, and a smaller apparent size. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The deep structure of Gorringe Bank (NE Atlantic) and its surrounding area     

Andrée Bergeron  Jean Bonnin 《Geophysical Journal International》1991,105(2):491-502

  相似文献   

Determination of parental magmas of HED cumulates: The effects of interstitial melts     

Jean‐Alix BARRAT 《Meteoritics & planetary science》2004,39(11):1767-1779

Abstract— An evaluation of trapped melts effects during crystallization and subsolidus equilibration of cumulates is necessary to constrain the composition of their parental magmas. In this paper, a simple mass balance approach is described. It allows estimation of trace element abundances in these parental melts from phase compositions. It is used to discuss the genesis of cumulate eucrites and diogenites. The REE behavior is in full agreement with the view that cumulate eucrites formed from melts similar to noncumulate eucrites. Trapped melt fractions ranging from <10 wt% for Moama to ?30 wt% for Moore County were involved. The origin of diogenites is more complex. The assumption that eucrites and diogenites shared the same parental melts cannot satisfactorily explain the diversity of incompatible trace element ratios (e.g., Dy/Yb) observed in diogenitic orthopyroxenes, even if interstitial melt effects are taken into account. Moreover, some diogenites unambiguously crystallized from magmas displaying significant HREE (heavy rare earth elements) enrichments. More likely, diogenites formed from distinct batches of parental magmas, as previously proposed by Mittlefehldt (1994), Fowler et al. (1995), and Shearer (1997).  相似文献   

La fondation et l'activité de l'Institut Géophysique Roland Eötvös de Hongrie     

Dr. Jean Renner 《Pure and Applied Geophysics》1948,13(1-2):6-10

Sans résumé  相似文献   

Two-surface versus multi-surface plasticity theories: A critical assessment     

Jean H. Prevost 《国际地质力学数值与分析法杂志》1982,6(3):323-338

It is the objective of this note critically to assess the merits and shortcomings of two-surface and multi-surface plasticity theories.  相似文献   

Report of the International Association of Geoanalysts on the Certification of Penrhyn Slate, OU-6   总被引：2，自引：2，他引：0  

Jean S. Kane 《Geostandards and Geoanalytical Research》2005,29(2):237-239

  相似文献   

CLAIRE: First light for a gamma-ray lens     

Peter von Ballmoos  Hubert Halloin  Jean Evrard  Gerry Skinner  Nikolai Abrosimov  Jose Alvarez  Pierre Bastie  Bernard Hamelin  Margarida Hernanz  Pierre Jean  Jürgen Knödlseder  Bob Smither 《Experimental Astronomy》2005,20(1-3):253-267

The objective of the R&D project CLAIRE was to prove the principle of a gamma-ray lens for nuclear astrophysics. CLAIRE's Laue diffraction lens has a diameter of 45 cm and a focal length of 277 cm; 556 germanium-silicon crystals are tuned to focus 170 keV photons onto a 1.5 cm diameter focal spot. Laboratory measurements of the individual crystals and the entire lens have been used to validate a numerical model that we use to estimate the lens performance for a source at infinity. During a stratospheric balloon flight on 2001 June 14, CLAIRE was directed at the Crab nebula by a pointing system able to stabilize the lens to within a few arcseconds of the target. In 72 min of valid pointing time, 33 photons from the Crab were detected in the 3 keV bandpass of the lens: CLAIRE's first light! The performance of CLAIRE's gamma-ray lens, namely the peak reflectivity for a polychromatic source (9±1%), has been confirmed by ground data obtained on a 205 meter long test range. CLAIRE's measured performance validates the principle of a Laue lens for nuclear astrophysics, opening the way for a space-borne gamma-ray lens telescope that will achieve one to two orders of magnitude improvement in sensitivity over present technologies.  相似文献   

Accretion and tectono-sedimentary progradation: The Taranto Gulf (Southern Italy)     

Georges Mascle  Jean Mascle 《Geo-Marine Letters》1984,3(1):9-12

The geological structures of the eastern Calabrian Apenninic front within the Gulf of Taranto, southern Italy, are compared to those of a convergent margin, using simple criteria such as the origin and volume of the sediment supply, and the relative ratio between sediments carried by the sinking plate and those directly supplied by the overriding margin. Based on this criteria we distinguish four main types of sedimentary accretion occurring at convergent continental margins: (a) Pacific type, (b) Indonesian type, (c) Caribbean type, and (d) Apenninic type.  相似文献   

K/Ar ages and stress pattern in the Azores: Geodynamic implications     

Gilbert Feraud  Ishiro Kaneoka  Claude Jean Allègre 《Earth and Planetary Science Letters》1980,46(2):275-286

We have dated by the K/Ar method the oldest volcanic formations known in the Azores archipelago. The results show a development of this oceanic island system from 5.5 m.y. to the present day.The age pattern is not compatible with a simple migration over a small fixed hot spot, but, plotting tectonic directions which control the volcanism versus age and distance to the Mid-Atlantic Ridge, a simple relationship seems to appear showing an anisotropic but fixed distribution of stress orientation at least for the last 0.7 m.y.  相似文献   

Estimating parameters of the channel width–flow discharge relation using rill and gully channel junction data     

M. Pilar Salvador Sanchis  Dino Torri  Lorenzo Borselli  Rorke Bryan  Jean Poesen  Marta S. Yañez  Cati Cremer 《地球表面变化过程与地形》2009,34(15):2023-2030

Eroding channels can usually be characterized by a power relationship between channel width (W) and channel discharge (Q). This paper examines the WQ relation using a recently developed channel junction approach to extend the validity of the WQ relation and to develop a procedure for estimating the WQ exponent and proportionality coefficient. Rill and gully channel data from the literature, and new data collected in different badland areas and in a few forest mountain streams, are analysed. Analysis shows that the WQ relation for channel width collected in badlands and forests agrees with trends observed for cropland. The exponent increases with increasing channel width in a continuous fashion rather than in a step‐like way and tends to a maximum whose value ranges between 0·5 and 0·6. The proportionality coefficient can be split into two terms, one expressing the case in which an eroding channel can broaden, the other reflecting the difficulties in removing the less erodible clods or rock fragments from the channel bed. Its splitting allows the development of a more correct form of the WQ relation in agreement with modern approaches of channel geometry: one part has the dimension of a discharge and makes the power base dimensionless, while the other brings the dimension of a length, needed for the channel width, into the WQ relation. The interpretation of the two constants is supported by data collected in rainfall‐runoff simulation experiments conducted in the field. Values characterizing the two constants in some environments are also given. Nevertheless the approach is not sufficiently parameterized yet to be of practical use (e.g. in models or for estimating peak discharge in areas where rill channels have formed). Copyright © 2009 John Wiley & Sons, Ltd.  相似文献