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21.
On 22 October, 1980, near the solar central meridian in the western vicinity of a large spot group, a subflare of the two-ribbon type was observed. Three surges were associated with this flare. Their starting points were situated close to the principal flare patches on both sides of a short filament that was visible for only a few hours. True flow velocities and decelerations along the arch-shaped surge trajectories have been determined for two of the surges. The highest velocities were found at the onset of the surges.The event was studied from a series of H on- and off-band flltergrams taken with the Debrecen coronagraph of 53 cm aperture.  相似文献   
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To enhance global water use assessment, the WaterGAP3 model was improved for back-calculating domestic, manufacturing and thermoelectric water uses until 1950 for 177 countries. Model simulations were carried-out on a national scale to estimate water withdrawals and consumption as well as cooling water required for industrial processes and electricity production. Additionally, the amount of treated and untreated wastewater as generated by the domestic and manufacturing sectors was modeled. In the view of data availability, model simulations are based on key socio-economic driving forces and thermal electricity production. Technological change rates were derived from statistical records in order to consider developments in water use efficiency, which turned out to have a crucial role in water use dynamics. Simulated domestic and industrial water uses increased from ca. 300 km3 in 1950 to 1345 km3 in 2010, 12% of which were consumed and 88% of which were discharged back into freshwater bodies. The amount of domestic and manufacturing wastewater increased considerably over the last decade, but only half of it was untreated. The downscaling of the untreated wastewater volume to river basin scale indicates a matter of concern in East and Southeast Asia, Northern Africa, and Eastern and Southern Europe. In order to reach the Millennium Development Goals, securing water supply and the reduction of untreated wastewater discharges should be amongst the priority actions to be undertaken. Population growth and increased prosperity have led to increasing water demands. However, societal and political transformation processes as well as policy regulations resulting in new water-saving technologies and improvements counteract this development by slowing down and even reducing global domestic and industrial water uses.  相似文献   
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Zusammenfassung Die statistische Bearbeitung der Isotopenverhältnisse von Bleierzen des alpinmediterranen Raumes ergab den von W. E.Petrascheck behaupteten engen genetischen Zusammenhang zwischen den einzelnen metallogenetischen Provinzen des genannten Gebietes. Gleichzeitig weisen die Resultate auf einen engen Zusammenhang der Vererzungen mit der magmatisch-sedimentären Vorgeschichte des untersuchten Gebietes hin. Die alt- und jungpaläozoischen sowie die mesozoischen Vererzungen scheinen eine verhältnismäßig einfache Vorgeschichte zu besitzen; im Känozoikum tritt dagegen eine aus mehr heterogenen Quellen stammende Stoffzufuhr ein.
The statistical evaluation of the isotopic composition of ore leads from the Alpine-Mediterranean system seems to support the assumption of W. E.Petrascheck about the presence of a strong genetical connection between the individual metallogenetical provinces in this area. At the same time, the results indicate a strong connection between ore mineralization and the magmatical-sedimentological history of the studied area. The source system of the Early and Late Palaeozoic, as well as of the Mesozoic ores seem to possess a rather simple genetical history; in the Tertiary a supply of ore material from a more heterogeneous source is implied.

Résumé L'élaboration statistique des donnés de composition isotopique des mineraus de plomb provenant du système alpin-mediterranéen souligne la liaison génétique étroite entre les unités métallogéniques postulée par W. E.Petrascheck. Les résultats indiquent en même temps des rapports immédiats entre la métallogénie et l'évolution magmatique-sédimentaire de l'endroit. Quant aux minéralisations paléozoiques inférieures et supérieures ainsi que mésozoiques il semble s'agir de phénomènes plus globaux, tandis que les minéraus du Tertiaire relèvent des sources plus complexes.

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26.
Summary The distribution of strontium in 26 igneous rocks from the Tokaj Mountains, ranging from basalt to rhyolite has been determined by using stable isotope dilution techniques. The comparison with main component analytical data allows a classification of the different rock types (basalts, andesites, dacites, rhyolites) into only two distinctly separate genetic groups, which can be described schematically by independent liquid-solid fractionation processes. It is shown that alkaline metasomatism can produce Sr/Ca relationships similar to those developed in a liquid-solid fractionation process. Contamination by partial melting of crustal rocks, as well as magma contamination by transvaporizational mechanisms, results in similar changes in the Sr/Ca ratio, which therefore can be misleading in defining various stages of magma development.
Über die Geochemie des Strontiums in tertiären Erstarrungsgesteinen des Tokaj-Gebirges
Zusammenfassung Die Strontiumverteilung in 26 Erstarrungsgesteinen des Tokaj-Gebirges wurde mit der Isotopenverdünnungsmethode bestimmt. Der Vergleich mit den chemischen Hauptkomponenten läßt die Einteilung der verschiedenen Gesteinstypen (Basalte, Andesite, Dazite, Rhyolite) in nur zwei, genetisch voneinander deutlich verschiedenen Reihen zu; diese können schematisch als voneinander unabhängige Fraktionierungsprozesse zwischen liquider und fester Phase beschrieben werden. Es wird gezeigt, daß Alkalimetasomatose Sr/Ca-Beziehungen erzeugen kann, die denen durch Liquidus/Solidus-Fraktionierung hervorgerufenen ähnlich sind. Kontamination durch partielles Aufschmelzen von Krustengesteinen und Magmenkontamination durch Transvaporisationsprosesse bewirken ähnliche Änderungen im Sr/Ca-Verhältnis; dieses kann daher bei der Definition verschiedener Stadien der Magmenentwicklung zu Fehldeutungen führen.


With 3 Figures  相似文献   
27.
On February 15, 2013, after the observation of a brilliant fireball and a spectacular airburst over the southern Ural region (Russia), thousands of stones fell and were rapidly recovered, bringing some extremely fresh material for scientific investigations. We undertook a multidisciplinary study of a dozen stones of the Chelyabinsk meteorite, including petrographic and microprobe investigations to unravel intrinsic characteristics of this meteorite. We also study the short and long‐lived cosmogenic radionuclides to characterize the initial meteoroid size and exposure age. Petrographic observations, as well as the mineral compositions obtained by electron microprobe analyses, allow us to confirm the classification of the Chelyabinsk meteorite as an LL5 chondrite. The fragments studied, a few of which are impact melt rocks, contain abundant shock melt veins and melt pockets. It is likely that the catastrophic explosion and fragmentation of the Chelyabinsk meteoroid into thousands of stones was in part determined by the initial state of the meteoroid. The radionuclide results obtained show a wide range of concentrations of 14C, 22Na, 26Al, 54Mn, 57Co, 58Co, and 60Co, which indicate that the pre‐atmospheric object had a radius >5 m, consistent with other size estimates based on the magnitude of the airburst caused by the atmospheric entry and breakup of the Chelyabinsk meteoroid. Considering the observed 26Al activities of the investigated samples, Monte Carlo simulations, and taking into account the 26Al half‐life (0.717 Myr), the cosmic‐ray exposure age of the Chelyabinsk meteorite is estimated to be 1.2 ± 0.2 Myr. In contrast to the other radionuclides, 14C showed a very large range only consistent with most samples having been exposed to anthropogenic sources of 14C, which we associate with radioactive contamination of the Chelyabinsk region by past nuclear accidents and waste disposal, which has also been confirmed by elevated levels of anthropogenic 137Cs and primordial 40K in some of the Chelyabinsk fragments.  相似文献   
28.
In this paper, we show the important role of chaotic transients in Celestial Mechanics through the Sitnikov problem. We compare the two kinds of chaos, permanent and transient, and provide the chaotic saddle of the Sitnikov problem giving also some important quantitative properties of this fractal set. Additionally, we present a link between the stickiness effect of tori and chaotic scattering.  相似文献   
29.
In this study, we use a combined biomarker and macrofossil approach to reconstruct the Holocene climate history recorded in Trifna Sø, Skallingen area, eastern North Greenland. Chronological information is derived from comparison of lithological, biogeochemical and macrofossil characteristics with a well‐dated record from nearby Lille Sneha Sø. Following local deglaciation around c. 8 cal. ka BP, the local peak warmth occurred between c. 7.4 and 6.2 cal. ka BP as indicated by maximum macrofossil abundances of warmth‐demanding plants (Salix arctica and Dryas integrifolia) and invertebrates (Daphnia pulex and Chironomidae). Warm conditions were dominated by terrestrial organic matter (OM) sedimentation as implied by the alkane‐based Paq ratio, but increased aquatic productivity is indicated when temperature was highest around 6.5 cal. ka BP. The n‐C29/n‐C31 alkane ratio shows that vegetation in the catchment was dominated by shrubs after deglaciation, but shifted towards relatively more grassy/herbaceous vegetation during peak warmth. After 5.4 cal. ka BP, the disappearance of warmth‐demanding plant and invertebrate macrofossils indicates cooling in the Skallingen area. This cooling was characterized by a significant shift towards dominance of aquatic OM sedimentation in Trifna Sø as implied by high Paq ratios. Cooling was also associated with a shift in vegetation type from dwarf‐shrub heaths towards relatively more herbaceous vegetation in the catchment, stronger erosion and more oligotrophic conditions in the lake. Our data show that mean air temperatures inferred using branched glycerol dialkyl glycerol tetraethers (brGDGTs) do not seem to accurately reflect the local climatic history. Irrespective of calibration, methylation of branched tetraethers (MBT) palaeothermometry cannot be reconciled with the macrofossil evidence and seems to be biased by either changing brGDGT sources (in situ vs. soil‐derived) or changing species assemblages and/or an unknown physiological response to changing environmental conditions at high latitude.  相似文献   
30.
The distribution and amount of groundwater, a crucial source of Earth’s drinking and irrigation water, is changing due to climate-change effects. Therefore, it is important to understand groundwater behavior in extreme scenarios, e.g. drought. Shallow groundwater (SGW) level fluctuation under natural conditions displays periodic behavior, i.e. seasonal variation. Thus, the study aims to investigate (1) the periodic behavior of the SGW level time series of an agriculturally important and drought-sensitive region in Central-Eastern Europe – the Carpathian Basin, in the north-eastern part of the Great Hungarian Plain, and (2) its relationship to the European atmospheric pressure action centers. Data from 216 SGW wells were studied using wavelet spectrum analysis and wavelet coherence analyses for 1961–2010. Locally, a clear relationship exists between the absence of annual periodic behavior in the SGW level and the periodicity of droughts, as indicated by the self-calibrating Palmer Drought Severity Index and the Aridity Index. During the non-periodic intervals, significant drops in groundwater levels (average 0.5 m) were recorded in 89% of the wells. This result links the meteorological variables to the periodic behavior of SGW, and consequently, drought. On a regional scale, Mediterranean cyclones from the Gulf of Genoa (northwest Italy) were found to be a driving factor in the 8-yr periodic behavior of the SGW wells. The research documents an important link between SGW levels and local/regional climate variables or indices, thereby facilitating the necessary adaptation strategies on national and/or regional scales, as these must take into account the predictions of drought-related climatic conditions.  相似文献   
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