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931.
B25 The site testing for the Thirty Meter Telescope and its potential role in developing the shortterm forecasting of observing conditions B34 LUCIFER: a NIR Spectrograph and Imager for the LBT B41 PEPSI: the Potsdam Echelle Polarimetric and Spectroscopic Instrument for the Large Binocular Telescope B44 LUCIFER: High Redshift Science Cases B49 Feedback in galaxy cores: a LBT Key Science Project proposal B52 SERPIL/LIINUS: a design study for a Near‐Infrared Interferometric Integral Field Spectrometer for the LBT B64 The Construction of the Large Binocular Telescope B73 Operating the LUCIFER Instrument B85 M92 – a crucial testbed for atomic diffusion and mixing in stars B142 The Large Binocular Camera at LBT B148 LUCIFER and its Exposure‐Time‐Calculator B196 The Multi‐Object Double Spectrograph and Nulling Interferometer for the Large Binocular Telescope B199 The Laser Guide Star Facility for the LBT B231 The PEPSI “deep spectrum” project B236 Zeeman‐Doppler imaging from Stokes IQUV line profiles B257 D3Dnet: getting ready for MUSE, a 2nd Generation Instrument for the VLT 相似文献
932.
Irene M. Farnham Klaus J. Stetzenbach Ashok K. Singh Kevin H. Johannesson 《Mathematical Geology》2000,32(8):943-968
The origin of groundwater discharging via evapotranspiration and from springs within Oasis Valley, Nevada, is of concern owing to the close proximity of the Nevada Test Site (NTS) and the possible contamination of groundwater as a result of underground nuclear testing. Principal components analysis, cluster analysis, and population partitioning, along with a Geographical Information System, were used to decipher groundwater flow patterns in Oasis Valley, Nevada. These multivariate statistical techniques were applied to the trace element chemistry of groundwater samples collected from 26 springs and wells within Oasis Valley, the NTS, and the Nellis Air Force Range. The results of all statistical analyses showed similar geographical trends in the trace element chemistry of the groundwaters included in this study. Differences are observed between the groundwaters from the NTS and those of Oasis Valley based on the concentrations of the elements Li, Ge, Mo, Rb, Ba, U, and Ru. A concentration gradient is observed from lower concentrations in the NTS to increasing concentrations toward Oasis Valley suggesting groundwater flow in an overall southwestward direction from the NTS. Also, a different trace element signature is observed for the waters collected in the northern and western region of Oasis Valley, suggesting another source of groundwater to this area. 相似文献
933.
The Preparation and Preliminary Characterisation of Eight Geological MPI-DING Reference Glasses for In-Situ Microanalysis 总被引:13,自引:4,他引:9
Klaus Peter Jochum Donald B. Dingwell Alexander Rocholl Brigitte Stoll Albrecht W. Hofmann S. Becker A. Besmehn D. Bessette H.-J. Dietze P. Dulski J. Erzinger E. Hellebrand P. Hoppe I. Horn K. Janssens G.A. Jenner M. Klein W.F. McDonough M. Maetz K. Mezger C. Müker I.K. Nikogosian C. Pickhardt I. Raczek D. Rhede H.M. Seufert S.G. Simakin A.V. Sobolev B. Spettel S. Straub L. Vincze A. Wallianos G. Weckwerth S. Weyer D. Wolf M. Zimmer 《Geostandards and Geoanalytical Research》2000,24(1):87-133
Eight silicate glasses were prepared by directly fusing and stirring 50-100 g each of basalt, andesite, komatiite, peridotite, rhyolite, and quartz-diorite. These are referred to as MPI-DING glasses and were made for the purpose of providing reference materials for geochemical, in-situ microanalytical work. Results from various analytical techniques indicate that individual glass fragments are well homogenised with respect to major and trace elements at the μm to mm scale. Heterogeneities due to quench crystallisation of olivine have been observed in small and limited areas of the two komatiitic glasses. In order to obtain concentration values for as many elements as possible, the glasses were analysed by a variety of bulk and microanalytical methods in a number of laboratories. The analytical uncertainties of most elements are estimated to be between 1% and 10%. From the analytical data, preliminary reference values for more than sixty elements were calculated. The analytical uncertainties of most elements are estimated to be between 1% and 10%. 相似文献
934.
935.
Klaus Hornung Yuri G. Malama Khaim S. Kestenboim 《Astrophysics and Space Science》2000,274(1-2):355-363
We report on theoretical efforts to understand the process of vaporization and ion formation upon hypervelocity impact of
small cosmic dust particles on a solid surface. Such collisions occur at the surface of solid bodies within the planetary
system, which do not have an atmosphere as well as in various actual and upcoming space missions for in-situ measurements
of interplanetary, interstellar and cometary dust. The investigation uses Godunov's method to simulate the impact. For the
very high velocitites investigated, the impacting dust particle as well as parts of the target vaporize and some of the vapor
cloud may change to partially ionized. Numerical results of the impact process are communicated for an 80 kms-1impact of a slightly porous SiO2 particle on a compact SiO2surface. Values of the amount of vapor and liquid excavated from the target are given. Ionization rates are calculated for
the example investigated and an estimate is given how this extrapolates to the highest conceivable velocities in the planetary
system (above 100 km s-1).
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
936.
High resolution climate simulations over the Arctic 总被引:1,自引:0,他引:1
Annette Rinke Klaus Dethloff Arne Spekat Wolfgang Enke Jens Hesselbjerg Christensen 《Polar research》1999,18(2):143-150
The regional atmospheric climate model HIRHAM has been applied to the Arctic. Simulations for the whole year 1990 and for an ensemble of winter months (January of 1985-1995) have been performed. The comparison of the simulations with observational data analyses shows that the general spatial patterns are in good agreement with the data, in both the vertical structure and the annual cycle. For an additional validation of the model results, a multivariate classification of large-scale circulation patterns has been applied to the January ensemble model simulations. 相似文献
937.
938.
Gaël Cazes David Fink Alexandru T. Codilean Réka-Hajnalka Fülöp Toshiyuki Fujioka Klaus M. Wilcken 《地球表面变化过程与地形》2020,45(2):424-439
We use cosmogenic 10Be and 26Al in both bedrock and fluvial sediments to investigate controls on erosion rates and sediment supply to river basins at the regional scale in the Kimberley, NW Australia. The area is characterised by lithologically controlled morphologies such as cuestas, isolated mesas and extensive plateaus made of slightly dipping, extensively jointed sandstones. All sampled bedrock surfaces at plateau tops, ridgelines, and in the broader floodplain of major rivers over the region show similar slow lowering rates between 0.17 and 4.88 m.Myr-1, with a mean value of 1.0 ± 0.6 m.Myr-1 (n=15), whilst two bedrock samples collected directly within river-beds record rates that are one to two orders of magnitude higher (14.4 ± 1.5 and 20.9 ± 2.5 m.Myr-1, respectively). Bedrock 26Al/10Be ratios are all compatible with simple, continuous sub-aerial exposure histories. Modern river sediment yield lower 10Be and 26Al concentrations, apparent 10Be basin-wide denudation rates ranging between 1.8 and 7.7 m.Myr-1, with a median value of 2.6 m.Myr-1, more than double the magnitude of bedrock erosion rates. 26Al/10Be ratios of the sediment samples are lower than those obtained for bedrock samples. We propose that these depleted 26Al/10Be ratios can largely be explained by the supply of sediment to river basins from the slab fragmentation and chemical weathering of channel gorge walls and plateau escarpments that result in diluting the cosmogenic nuclide concentration in river sediments measured at the basin outlets. The results of a mass-balance model suggest that ~60–90% of river sediment in the Kimberley results from the breakdown and chemical weathering of retreating vertical sandstone rock-walls in contrast to sediment generated by bedrock weathering and erosion on the plateau tops. This study emphasises the value of analysing two or more isotopes in basin-scale studies using cosmogenic nuclides, especially in slowly eroding post-orogenic settings. © 2019 John Wiley & Sons, Ltd. 相似文献
939.
940.
The transition from porphyry- to epithermal-style gold mineralization at Ladolam, Lihir Island, Papua New Guinea: a reconnaissance study 总被引:8,自引:0,他引:8
Daniel Müller Klaus Kaminski Stephan Uhlig Torsten Graupner Peter M. Herzig Steve Hunt 《Mineralium Deposita》2002,37(1):61-74
The exceptionally large gold resource at Ladolam (>1,300 metric tons of gold), Lihir Island, resulted from the transition of an early-stage, low-grade porphyry gold system to a low-sulfidation epithermal gold event. This transition was probably triggered by rapid decompression during the partial slope failure of Luise stratovolcano and accompanied by the ingress of seawater. The original porphyry stage is indicated by remnant hydrothermal breccia clasts of strongly biotite-magnetite altered monzodiorite with disseminated pyrite - chalcopyrite and poorly developed pyrite - quartz stockwork veins. The breccias are overprinted by biotite-magnetite alteration and their matrix is strongly mineralized with disseminated auriferous pyrite. The breccias are cut by late-stage epithermal quartz-chalcedony-illite-adularia-pyrite veins and associated illite-adularia alteration that locally contain bonanza gold grades of up to 120 g/t. Isotope data suggest a magmatic source of sulfur in the gold-bearing fluids at Ladolam. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00126-001-0230-y 相似文献