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61.
Marie‐Jeanne Teil Martine Blanchard Cendrine Dargnat Karen Larcher‐Tiphagne Marc Chevreuil 《水文研究》2007,21(18):2515-2525
The occurrence and fate of six phthalate esters were investigated in the River Seine and two tributaries in the Paris area, at six sites from upstream to downstream, throughout different seasons, with special attention given to a flood episode. At all sites, except the River Marne, whatever the period, diethylhexyl phthalate (DEHP) displayed the highest concentration (0·323–0·779 µg l?1 as mean values), followed by di‐n‐butyl phthalate (DnBP; 0·211–0·526 µg l?1 as mean values), which is consistent with the production pattern. High phthalate concentrations appeared to be related to population density and industrial distribution. The strongest values were located downstream from wastewater treatment plant effluent inputs. Seasonal variations were closely related to river flow and air and water temperature. The annual evolution of phthalates was linked to the hydrological conditions. During the flood episode at Paris, the DEHP concentration displayed a sharp increase (260 to 1123 ng l?1) occurring 9 days before the flood peak. The simultaneous fluctuations of NH4, typical of domestic origin, and of DEHP suggests a similar origin from combined sewer overflows for both compounds. Other elevated values corresponded to the highest precipitation amounts, and demonstrated the contribution of non‐point‐source runoff and wastewater overflow to DEHP inputs. The DEHP concentration relationship with river flow displayed a clockwise hysteresis loop, corresponding to a ‘first‐flush’ effect in which the finite supplies are swept along in the early stage of the flood. Annual fluxes for 2004 at Paris were 2257 kg of DEHP and 1613 kg of DnBP. The flood period seemed to have a minor impact on annual phthalate transport (29·5% and 41% of the total for DEHP and for DnBP, respectively), which is contrary to annual suspended solids transport (69%). Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
62.
63.
Notburga Kapferer Ivan Mercolli Alfons Berger Maria Ovtcharova Bernhard Fügenschuh 《Swiss Journal of Geoscience》2012,105(1):67-84
The high-pressure metamorphic rocks of the Sesia?CLanzo zone are partly covered by a volcano-sedimentary unit, the Biella Volcanic Suite. Calc-alkaline and shoshonitic lavas extruded sub-aerially on the Oligocene surface. Uranium?CLead zircon dating yields 32.44?C32.89?Ma for the eruption of the calc-alkaline lavas and therefore fixes a minimum age for the paleosurface. The Biella Volcanic Suite consists mainly of epiclastic rocks deposited in a high-energy fluvial environment and minor lava flows. The rocks of the suite display widespread post-eruption transformations. Illite and chlorite thermometry as well as fission track dating suggest a thermal overprint related to burial of the Biella Volcanic Suite. An upper crustal rigid block tilting in the area causes this burial. Hydrothermal tourmaline and ankerite veins related to the intrusion of the nearby Valle del Cervo Pluton crosscut the already tilted Biella Volcanic Suite. The intrusion age of Valle del Cervo Pluton at 30.39?±?0.50?Ma sets therefore the lower time limit for tectonic processes responsible for the tilting and burial. After the burial, the Biella Volcanic Suite remained for around 20?million years between the zircon and the apatite partial annealing zone. The apatite fission track ages spread between 16 and 20?Ma gives the time frame for the second exhumation of these units. The Biella Volcanic Suite and the adjacent rocks of the Sesia?CLanzo zone were the second time exhumed to the surface in Messinian times, after a long residence time within the apatite partial annealing zone. 相似文献
64.
The aim of this paper is to improve understanding of the adaptive capacity of European agriculture to climate change. Extensive
data on farm characteristics of individual farms from the Farm Accountancy Data Network (FADN) have been combined with climatic
and socio-economic data to analyze the influence of climate and management on crop yields and income and to identify factors
that determine adaptive capacity. A multilevel analysis was performed to account for regional differences in the studied relationships.
Our results suggest that socio-economic conditions and farm characteristics should be considered when analyzing effects of
climate conditions on farm yields and income. Next to climate, input intensity, economic size and the type of land use were
identified as important factors influencing spatial variability in crop yields and income. Generally, crop yields and income
are increasing with farm size and farm intensity. However, effects differed among crops and high crop yields were not always
related to high incomes, suggesting that impacts of climate and management differ by impact variable. As farm characteristics
influence climate impacts on crop yields and income, they are good indicators of adaptive capacity at farm level and should
be considered in impact assessment models. Different farm types with different management strategies will adapt differently. 相似文献
65.
Fluid inclusion petrography 总被引:32,自引:0,他引:32
66.
Carbonic inclusions 总被引:17,自引:0,他引:17
The paper gives an overview of the phase relations in carbonic fluid inclusions with pure, binary and ternary mixtures of the system CO2–CH4–N2, compositions, which are frequently found in geological materials. Phase transitions involving liquid, gas and solid phases in the temperature range between −192°C and 31°C are discussed and presented in phase diagrams (PT, TX and VX projections). These diagrams can be applied for the interpretation of microthermometry data in order to determine fluid composition and molar volume (or density). 相似文献
67.
Valentino Di Donato Paola Esposito Elda Russo-Ermolli Arianna Scarano Rachid Cheddadi 《Quaternary International》2008,190(1):146
Planktonic foraminifera and pollen data from core GNS84-C106 (Gulf of Salerno, Tyrrhenian Sea) were analysed through the Modern Analogue Technique, Constrained Cluster Analysis and relative variation biplots. A long period of mild climate, centred around 25 ka BP, is evident in both marine and continental reconstructions. The cooling phase from 17 to 14.7 ka BP, correlated to the H1 Heinrich event, is indicated by a sea surface temperature (SST) decrease, which roughly coincides with the cold-arid phase identified by annual and January temperatures. A rapid increase in atmospheric temperatures and precipitation, culminating at 13.8 ka BP, marks the BA cronozone. The corresponding increase in summer and winter SSTs, of 11 and 6.5 °C, respectively, occurred over 600 years. The beginning of the YD, centred around 12.5 ka BP, is marked by a decrease in summer and winter SSTs of, respectively, 4.5 and 3.5 °C in one century. The atmospheric evidence of the YD is primarily reflected in low January temperatures, reaching −6 °C, the lowest values ever experienced in the analysed time interval. The Late Glacial–Holocene transition is clearly recorded in both the continental and marine realms. From 11.5 to 9 ka BP, atmospheric temperatures record a period of substantial stability followed by a drop at 8.9 ka BP, which chronologically fall within the first RCC event (9–8 ka BP) of Mayewski et al. [2004. Holocene climate variability. Quaternary Research 62, 243–255], in correspondence with a phase of relatively high seasonality, indicated by foraminifera. 相似文献
68.
Dr. Alfons Zehnder 《Aquatic Sciences - Research Across Boundaries》1973,35(1):121-135
Ohne Zusammenfassung
Internationale Arbeitsgemeinschaft für Cyanophytenforschung IAC 相似文献
69.
Differences in reactivities of sedimentary hopane diastereomers when heated in the presence of clays
Mixtures of hopane diastereomers obtained by fractionation of the organic extract from an immature oil shale have been heated in the presence of clay-containing substrates. In experiments conducted at 250°C with an extracted source rock as the substrate, the relative amounts of 17β(H),21β (H)-hopanes were found to decrease with respect to the moretanes and 17α(H),21β(H)-hopanes in a manner parallelling that observed with increasing maturity in sediments. In this case however, the change was shown to be due to the selective removal of the 17β(H),21β(H)-hopanes, rather than conversion of these compounds into the other diastereomers. In order to assess whether the use of elevated temperatures was enhancing processes other than those which operate in natural systems, a second experiment was conducted in which the sample of immature hopanes was heated at 75°C with the very catalytically active substrate aluminum montmorillonite. In this experiment also, the changes in hopane composition was shown to be due to selective removal of 17β(H),21β(H)-hopanes rather than conversion into the corresponding compounds in the other two series of diastereomers. These results suggest that the observed relative depletion of 17β(H),21β(H)-hopanes in sedimentary rocks of increasing maturity may similarly be due to removal by selective catalytic processes, and not to interconversion processes associated with isomerisation at C-17 and C-21 as had previously been believed. 相似文献
70.
Experimental analysis and modelling of shallow landslides 总被引:1,自引:1,他引:1
The paper presents the results of some experimental tests reproducing the triggering mechanism of a special kind of shallow
landslides induced by rainfalls (soil slip) in a physical 1-g model. The experimental data have been employed to verify the
capability of a simplified stability model to describe the phenomenon and to back-analyse its occurrence in a case history
(Pizzo d’Alvano, Campania Region 1998). The method enables a direct correlation between the safety factor of a slope and rainfall
intensity, as well as antecedent rainfalls. 相似文献