Genetic relationship between silver–lead–zinc mineralization in the Wutong deposit,Guangxi Province and Mesozoic granitic magmatism in the Nanling belt,southeast China     

Pilar Lecumberri-Sanchez  Rolf L. Romer  Volker Lüders  Robert J. Bodnar 《Mineralium Deposita》2014,49(3):353-369

More than 50 % of the world's total reserves of tungsten are in China and most tungsten deposits are located in the Nanling range in southeast China. This study explores the potential genetic relationship between tungsten–tin (W–Sn) mineralization and shallower Ag–Pb–Zn deposits in the Nanling range based on data from the Wutong deposit, Guangxi Province. The lead, oxygen, carbon, sulfur, and strontium isotopic compositions of minerals at Wutong indicate that a single crustal-derived fluid was responsible for mineralization. Wutong likely formed at relatively low temperatures (～200–300 °C) and low pressures, as indicated by the similarity between homogenization temperatures of fluid inclusions and those estimated from S isotopic compositions of minerals. The hübnerite age (92.3–104.4 Ma) indicates that the Wutong mineralization is likely related to nearby Late Yanshanian (Cretaceous) S-type granites derived from Proterozoic crust. This mineralization event coincides with the last W–Sn mineralization event and the Cretaceous peak of mineralization in the Nanling range.  相似文献   

Geochemistry of Neogene quartz andesites from the Oaş and Gutâi Mountains,Eastern Carpathians (Romania): a complex magma genesis     

Maria Jurje  Corina Ionescu  Volker Hoeck  Marinel Kovacs 《Mineralogy and Petrology》2014,108(1):13-32

The Neogene quartz andesites from the Oa? and Gutâi Mountains (Romania) are mid-K calc-alkaline rocks and contain plagioclase-orthopyroxene-clinopyroxene-amphibole-magnetite phenocrysts as well as quartz crystals. They are associated with a volcanic sequence ranging from basalts and basaltic andesites to dacites and rhyolites, but form a separate magma group, mostly in respect to the trace elements. Based on the geochemical data combined with inferences from complex zoning patterns in plagioclase and pyroxene, the evolution of quartz andesites is interpreted in terms of fractional crystallization, AFC and magma mixing. A parental magma deriving from a MORB- or OIB-type source modified by fluids and melts originating from sediments is envisaged.  相似文献   

Cosmic reionization by stellar sources: population III stars     

Aaron Sokasian  Naoki Yoshida  Tom Abel  Lars Hernquist  Volker Springel 《Monthly notices of the Royal Astronomical Society》2004,350(1):47-65

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The formation of close binary systems by dynamical interactions and orbital decay     

Matthew R. Bate  Ian A. Bonnell  Volker Bromm 《Monthly notices of the Royal Astronomical Society》2002,336(3):705-713

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Derivation of planetary topography using multi-image shape-from-shading   总被引：1，自引：0，他引：1  

Volker Lohse  Christian Heipke 《Planetary and Space Science》2006,54(7):661-674

In many cases, the derivation of high-resolution digital terrain models (DTMs) from planetary surfaces using conventional digital image matching is a problem. The matching methods need at least one stereo pair of images with sufficient texture. However, many space missions provide only a few stereo images and planetary surfaces often possess insufficient texture.This paper describes a method for the generation of high-resolution DTMs from planetary surfaces, which has the potential to overcome the described problem. The suggested method, developed by our group, is based on shape-from-shading using an arbitrary number of digital optical images, and is termed “multi-image shape-from-shading” (MI-SFS). The paper contains an explanation of the theory of MI-SFS, followed by a presentation of current results, which were obtained using images from NASA's lunar mission Clementine, and constitute the first practical application with our method using extraterrestrial imagery. The lunar surface is reconstructed under the assumption of different kinds of reflectance models (e.g. Lommel-Seeliger and Lambert). The represented results show that the derivation of a high-resolution DTM of real digital planetary images by means of MI-SFS is feasible.  相似文献   

Role of renewable energy in climate mitigation: a synthesis of recent scenarios     

Volker Krey 《Climate Policy》2013,13(4):1131-1158

The role of renewable energy in climate change mitigation is explored through a review of 162 recent medium- to long-term scenarios from 15 large-scale, energy-economic and integrated assessment models. The current state of knowledge from this community is assessed and its implications drawn for the strategic context in which policymakers and other decision-makers might consider renewable energy. The scenario set is distinguished from previous ones in that it contains more detailed information on renewable deployment levels. All the scenarios in this study were published during or after 2006. Within the context of a large-scale assessment, the analysis is guided primarily by four questions. What sorts of future levels of renewable energy deployment are consistent with different CO₂ concentration goals? Which classes of renewable energy will be the most prominent energy producers and how quickly might they expand production? Where might an expansion in renewable energy occur? What is the linkage between the costs of mitigation and an expansion of renewable energy?  相似文献   

The effect of sideband ratio on line intensity for Herschel/HIFI     

Ronan Higgins  David Teyssier  Colin Borys  Jonathan Braine  Claudia Comito  Bertrand Delforge  Frank Helmich  Michael Olberg  Volker Ossenkopf  John Pearson  Russell Shipman 《Experimental Astronomy》2014,37(2):433-452

The Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory is composed of a set of fourteen double sideband mixers. We discuss the general problem of the sideband ratio (SBR) determination and the impact of an imbalanced sideband ratio on the line calibration in double sideband heterodyne receivers. The HIFI SBR is determined from a combination of data taken during pre-launch gas cell tests and in-flight. The results and some of the calibration artefacts discovered in the gas cell test data are presented here along with some examples of how these effects appear in science data taken in orbit.  相似文献   

Physical viscosity in smoothed particle hydrodynamics simulations of galaxy clusters   总被引：1，自引：0，他引：1  

Debora Sijacki  Volker Springel 《Monthly notices of the Royal Astronomical Society》2006,371(3):1025-1046

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Book reviews     

Schliephake  Konrad  Mitchel  N. C.  Stadel  Christoph  Hoffmann  Christoph  Kaminske  Volker  Schlichtmann  Hansgeorg  Leinbach  Thomas R. 《GeoJournal》1986,13(3):294-296

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Cosmological smoothed particle hydrodynamics simulations: the entropy equation   总被引：2，自引：0，他引：2  

Volker Springel  Lars Hernquist 《Monthly notices of the Royal Astronomical Society》2002,333(3):649-664

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