Multitracer test approach to characterize reactive transport in karst aquifers   总被引：7，自引：0，他引：7  

Geyer T  Birk S  Licha T  Liedl R  Sauter M 《Ground water》2007,45(1):36-45

A method to estimate reactive transport parameters as well as geometric conduit parameters from a multitracer test in a karst aquifer is provided. For this purpose, a calibration strategy was developed applying the two-region nonequilibrium model CXTFIT. The ambiguity of the model calibration was reduced by first calibrating the model with respect to conservative tracer breakthrough and later transferring conservative transport parameters to the reactive model calibration. The reactive transport parameters were only allowed to be within a defined sensible range to get reasonable calibration values. This calibration strategy was applied to breakthrough curves obtained from a large-scale multitracer test, which was performed in a karst aquifer of the Swabian Alb, Germany. The multitracer test was conducted by the simultaneous injection of uranine, sulforhodamine G, and tinopal CBS-X. The model succeeds to represent the tracer breakthrough curves (TBCs) of uranine and sulforhodamine G and verifies that tracer-rock interactions preferably occur in the immobile fluid region, although the fraction of this region amounts to only 3.5% of the total water. However, the model failed to account for the long tailing observed in the TBC of tinopal CBS-X. Sensitivity analyses reveal that model results for the conservative tracer transport are most sensitive to average velocity and volume fraction of the mobile fluid region, while dispersion and mass transfer coefficients are least influential. Consequently, reactive tracer calibration allows the determination of sorption sites in the mobile and immobile fluid region at small retardation coefficients.  相似文献   

Monthly, seasonal and annual temperature reconstructions for Central Europe derived from documentary evidence and instrumental records since AD 1500   总被引：2，自引：0，他引：2  

Petr Dobrovolný  Anders Moberg  Rudolf Brázdil  Christian Pfister  Rüdiger Glaser  Rob Wilson  Aryan van Engelen  Danuta Limanówka  Andrea Kiss  Monika Halíčková  Jarmila Macková  Dirk Riemann  Jürg Luterbacher  Reinhard Böhm 《Climatic change》2010,101(1-2):69-107

Monthly temperature series for Central Europe back to AD 1500 are developed from documentary index series from Germany, Switzerland and the Czech Republic (1500–1854) and 11 instrumental temperature records (1760–2007). Documentary evidence from the Low Countries, the Carpathian Basin and Poland are used for cross-checking for earlier centuries. The instrumental station records are corrected for inhomogeneities, including insufficient radiation protection of early thermometers and the urban heat island effect. For overlapping period (1760–1854), the documentary data series correlate with instrumental temperatures, most strongly in winter (86% explained variance in January) and least in autumn (56% in September). For annual average temperatures, 81% of the variance is explained. Verification statistics indicate high reconstruction skill for most months and seasons. The last 20 years (since 1988) stand out as very likely the warmest 20-year period, accounting for the calibration uncertainty and decreases in proxy data quality before the calibration period. The new reconstruction displays a previously unobserved long-term decrease in DJF, MAM and JJA temperature variability over last five centuries. Compiled monthly, seasonal and annual series can be used to improve the robustness of gridded large-scale European temperature reconstructions and possible impact studies. Further improvement of the reconstruction would be achieved if documentary data from other European countries are further developed.  相似文献   

The dynamics of Neptune Trojan – I. The inclined orbits     

Li-Yong Zhou  Rudolf Dvorak  Yi-Sui Sun 《Monthly notices of the Royal Astronomical Society》2009,398(3):1217-1227

The stability of Trojan type orbits around Neptune is studied. As the first part of our investigation, we present in this paper a global view of the stability of Trojans on inclined orbits. Using the frequency analysis method based on the fast Fourier transform technique, we construct high-resolution dynamical maps on the plane of initial semimajor axis a ₀ versus inclination i ₀. These maps show three most stable regions, with i ₀ in the range of  (0°, 12°), (22°, 36°)  and  (51°, 59°),  respectively, where the Trojans are most probably expected to be found. The similarity between the maps for the leading and trailing triangular Lagrange points L ₄ and L ₅ confirms the dynamical symmetry between these two points. By computing the power spectrum and the proper frequencies of the Trojan motion, we figure out the mechanisms that trigger chaos in the motion. The Kozai resonance found at high inclination varies the eccentricity and inclination of orbits, while the  ν₈  secular resonance around   i ₀∼ 44°  pumps up the eccentricity. Both mechanisms lead to eccentric orbits and encounters with Uranus that introduce strong perturbation and drive the objects away from the Trojan like orbits. This explains the clearance of Trojan at high inclination  (>60°)  and an unstable gap around  44°  on the dynamical map. An empirical theory is derived from the numerical results, with which the main secular resonances are located on the initial plane of  ( a ₀, i ₀)  . The fine structures in the dynamical maps can be explained by these secular resonances.  相似文献   

Remote sounding of atmospheres: (Cambridge planetary science series). J.T. Houghton,F.W. Taylor,and C.D. Rodgers. Cambridge Univ. Press,New York/Cambridge/London, 1984. 343 pp., $67.50     

Rudolf A. Hanel 《Icarus》1985,61(2):346-348

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The contribution of satellite geodesy to the geosciences     

Rudolf Sigl Dr.-Ing 《GeoJournal》1984,8(4):341-362

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沉积物中多环芳烃在海岸带水域自然环境中的衰减研究     

张勇  庄一廷  张杰  Ka-Fai Poon  Michael H W Lam  洪华生  Rudolf S S Wu 《台湾海峡》2001,20(2):171-176

本文在现场情况下，研究了自然条件下受污染海岸带沉积物中的7种多环芳烃（Polynuclear Aromatic Hydrocarbons，简称PAHs）的解吸动力学行为。结果表明，7种PAHs）的解吸动力学行为。结果表明，7种PAHs的解吸动力学行为可以用二元模型模拟。文中并将所得数据与文献报道的数据进行了比较。  相似文献   

Climatic fluctuation in the Czech Lands during the last millennium     

Rudolf Brázdil 《GeoJournal》1994,32(3):199-205

On the basis of documentary evidence, proxy-data and instrumental observations, the climatic fluctuation during the last millennium in the Czech Lands is analysed. According to narrative sources, the warmest period falls between the 1260s–1380s, documents for Lamb's (1984) Medieval Warm Epoch in 1150–1300 are missing. The prevalence of extremely cold and also rainy periods, as an expression of the Little Ice Age, is most conspicuous in the 15th century, in the 1590s and, with three interruptions, between the 1730s–1850s. Since the latter half of the 19th century a rising temperature trend has manifested itself. A regional climatic scenario for the model of global warming is discussed in relation to the observed trends in the Czech Lands.  相似文献   

Maturation thermique des roches mères dans les bassins des basses-terres du Saint-Laurent et dans quelques buttes témoins au sud-est du Bouclier canadien     

Rudolf Bertrand 《International Journal of Coal Geology》1991,19(1-4)

Caradocian source rocks belonging to the Utica Group occur around and overlay the southeastern part of the Canadian Shield from the Ottawa embayment, in the southwestern part of St. Lawrence Lowlands, to the Anticosti Island basin. The kerogen of the source rocks is mainly made up of amorphous organic matter (transmitted light), resembling a solid bitumen framework in reflected light, and contains a small portion of zooclasts (graptolites and chitinozoans). The kerogen is often too mature to have preserved the structure of the original constituents, except those of graptolites and chitinozoans. Otherwise, UV fluorescent colonial alga and tasmanites are observed.In the eastern half of the St. Lawrence Lowlands, stratigraphic and tectonic burial is the main control of source rock thermal maturation. From an area located 50 km west of Quebec City, the estimated vitrinite reflectance (R_o-Std) of the source rock increases in both northeastern (Montmorency Falls) and southwestern (St. Maurice River) directions, from R_o-Std of 1.2 to 1.5 and 1.7%, respectively. The source rocks of the Ottawa embayment and Montreal area (western half of the basin) are overmature due to hydrothermal and igneous activities (2.3%<R_o-Std<2.8%).. In Chicoutimi and Lac Saint-Jean outliers, the source rocks show reflectances between 0.9 and 1.2%, slightly less than reflectance values in the Quebec City area (R_o-Std between 1.2 and 1.5%). On Anticosti Island, the thermal maturation is related to burial only and increases downdip of the inclined platform, from the northeast toward the southwest (R_o-Std between 0.9 and 2.1%).These observations suggest that the St. Lawrence platform and the southeastern Canadian Shield were buried by at least 3.5 km of Paleozoic strata prior to erosion to Grenville basement. This implies that most potential hydrocarbon fields are presumably also lost by erosion.

Résumé

Des roches mères caradociennes, appartenant au Groupe d'Utica, sont trouvées autour et sur la partie sud-est du Bouclier canadien, du sous-bassin de la région d'Ottawa, dans la partie sud-ouest des basses-terres du Saint-Laurent jusqu'au bassin de l'île d'Anticosti. Le kérogène de ces roches mères est principalement constitué de matière organique amorphe (lumière transmise) ayant l'aspect d'un treillis fait de bitume solide lorsqu'il est observé en lumière incidente et contient une petite proportion de zooclastes (graptolites et chitinozoaires). Ce kérogène est souvent trop mature pour avoir préservé la structure originale de ses constituants, sauf celle des graptolites et des chitinozoaires. Dans le cas contraire, on observe des colonies algaires et des tasmanites fluorescentes à la lumière ultraviolette.Dans la moitié est des basses-terres du Saint-Laurent, l'enfouissement stratigraphique et tectonique contrôle la maturation thermique de la roche mère. D'un point situé à 50 km à l'ouest de Québec, la réflectance standardisée à celle de la vitrinite (R_h-Std) de la roche mère augmente tant vers le nord-est (Chutes Montmorency) que vers le sud-ouest (rivière Saint-Maurice), et varie entre 1,2 et 1,5 ou 1,7% respectivement. D'autre part, les roches mères des régions d'Ottawa et de Montréal (ouest du bassin) sont supramatures à cause d'activités hydrothermales et ignées (2,3%<R_h-Std<2,8%). Dans les buttes témoins du Saguenay et du Lac-Saint-Jean, les roches mères montrent des valeurs de la R_h-Std comprises entre 0,9 et 1,2%, légèrement inférieures à celles de la région de Québec (R_h-Std entre 1,2 et 1,5%). Dans l'île d'Anticosti, la maturation thermique est surtout reliée à l'enfouissement et s'accroît en direction de l'approfondissement de la plate-forme, du nord-est vers le sud-ouest (R_h-Std entre 0,9 et 2,1%).Ces observations suggèrent que la plate-forme du Saint-Laurent et le sud-est du Bouclier canadien furent enfouis sous au moins 3,5 km de strates paléozoïques avant que ces dernières soient érodées au niveau du socle grenvillien. Ceci implique que la majorité des gisements potentiels d'hydrocarbures furent probablement aussi perdus par érosion.  相似文献   

修筑寒区小型水利工程的经验回顾     

Rudolf V. Zhang 《冰川冻土》2004,26(Z1):12-20

The paper provides a review of experience with the construction of hydraulic projects in the permafrost regions. Principles for construction, operation and maintenance of earth dams are refined and formulated. High priority needs for improving the stability of structures are identified.  相似文献   

Anabaena bergii var.limnetica,nov. var., Cyanophyceae,Nostocaceae     

Alain Couté  Hans Rudolf Preisig 《Aquatic Sciences - Research Across Boundaries》1978,40(2):374-383

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