The 2dF Galaxy Redshift Survey: the population of nearby radio galaxies at the 1-mJy level     

Manuela Magliocchetti  Steve J. Maddox  Carole A. Jackson  Joss Bland-Hawthorn  Terry Bridges  Russell Cannon  Shaun Cole  Matthew Colless  Chris Collins  Warrick Couch  Gavin Dalton  Roberto de Propris  Simon P. Driver  George Efstathiou  Richard S. Ellis  Carlos S. Frenk  Karl Glazebrook  Ofer Lahav  Ian Lewis  Stuart Lumsden  John A. Peacock  Bruce A. Peterson  Will Sutherland  Keith Taylor 《Monthly notices of the Royal Astronomical Society》2002,333(1):100-120

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Phosphorus sequestration in Fe-rich sediments from two Brazilian tropical reservoirs     

R. Fonseca  T. Canário  M. Morais  F.J.A.S. Barriga 《Applied Geochemistry》2011,26(9-10):1607-1622

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Dolomitic slates from Uruguay: petrophysical and petromechanical characterization and deposit evaluation     

Manuela Morales Demarco  Pedro Oyhantçabal  Karl-Jochen Stein  Siegfried Siegesmund 《Environmental Earth Sciences》2013,69(4):1361-1395

Slates are internationally known as roof and façade-cladding material since prehistoric times. The methods required to mine and manufacture these dimensional stones are relatively simple in comparison to those utilized in granitic dimensional stones. This has led to a worldwide rentable commercialization of slate in the last centuries and also to the development of characteristic cultural landscapes. In Uruguay several slates are mined and used in architecture, especially as façade cladding and floor slabs. The most important slates regarding their production and utilization are the dolomitic slates. These dolomitic slates are associated with the Neoproterozoic thrust and fold belt of the Dom Feliciano belt. Representative samples have been geochemically and petrographically characterized, as well as petrophysically and petromechanically analyzed. The petrophysical and petromechanical properties were investigated in a very systematic way with respect to the new European standards, showing values comparable to those registered for internationally known slates. Detailed structural and deposit analysis were carried out in Uruguay in order to evaluate the dolomitic slate deposits. The slates are linked to calc-silicate strata in a greenschist facies volcano-sedimentary sequence and the deposits are located in the limb of a regional fold, where bedding and cleavage are parallel. The main lithotype is a layered and fine-grained dolomitic slate with a quite diverse palette of colors: light and dark green, gray, dark gray, reddish and black. The mined slate is split into slabs 0.5–2 cm thick. In the past, the average production in Uruguay was around 4,000 tons/year and a historical maximum of 13,000 tons was reached in 1993 (Oyhantçabal et al. in Z dt Ges Geowiss 158(3):417–428, 2007). The oscillations in the regional demand were the cause of several flourishing and decay cycles in the activity, but our investigation shows a considerable volume of indicated resources and therefore a very good potential.  相似文献   

Thermospheric/mesospheric temperatures on Venus: Results from ground-based high-resolution spectroscopy of CO2 in 1990/1991 and comparison to results from 2009 and between other techniques     

Guido Sonnabend  Peter Krötz  Frank Schmülling  Theodor Kostiuk  Jeff Goldstein  Manuela Sornig  Dušan Stupar  Timothy Livengood  Tilak Hewagama  Kelly Fast  Arnaud Mahieux 《Icarus》2012,217(2):856-862

We report temperatures in Venus’ upper mesosphere/lower thermosphere, deduced from reanalyzing very high resolution infrared spectroscopy of CO₂ emission lines acquired in 1990 and 1991. Kinetic temperatures at ～110 km altitude (0.15 Pa) are derived from the Doppler width of fully-resolved single line profiles measured near 10.4 μm wavelength using the NASA GSFC Infrared Heterodyne Spectrometer (IRHS) at the NASA IRTF on Mauna Kea, HI, close to Venus inferior conjunction and two Venus solstices. Measured temperatures range from ～200 to 240 K with uncertainty typically less than 10 K. Temperatures retrieved from similar measurement in 2009 using the Cologne Tuneable Heterodyne Infrared Spectrometer (THIS) at the NOAO McMath Telescope at Kitt Peak, AZ are 10–20 K lower. Temperatures retrieved more recently from the SOIR instrument on Venus EXpress are consistent with these results when the geometry of observation is accounted for. It is difficult to compare ground-based sub-mm retrievals extrapolated to 110 km due to their much larger field of view, which includes the night side regions not accessible to infrared heterodyne observations. Temperature variability appears to be high on day-to-day as well as longer timescales. Observed short term and long term variability may be attributed to atmospheric dynamics, diurnal variability and changes over solar activity and seasons. The Venus International Reference Atmosphere (VIRA) model predicts cooler temperatures at the sampled altitudes in the lower thermosphere/upper mesosphere and is not consistent with these measurements.  相似文献   

Estimation of streamflow recession parameters: New insights from an analytic streamflow distribution model     

Ana Clara Santos  Maria Manuela Portela  Andrea Rinaldo  Bettina Schaefli 《水文研究》2019,33(11):1595-1609

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The influence of the void fraction on the particle migration: A coupled computational fluid dynamics–discrete element method study about drag force correlations     

Manuela Kanitz  Juergen Grabe 《国际地质力学数值与分析法杂志》2021,45(1):45-63

Granular soils subjected to flow through their soil skeleton can show a behaviour in which fine particles migrate through the pore space between coarser particles. This process is called internal instability or suffusion. This contribution deals with the numerical analysis of the migration of fine particles in a soil column subjected to fluid flow with unresolved coupled computational fluid dynamics–discrete element method (CFD–DEM) with special regards to the used drag force correlation. The contribution investigates the influence of the Schiller–Naumann model and its extension with a voidage term on the migration behaviour of fine particles. The voidage term is further varied with a parameter, which controls the impact of the change of the void fraction on the drag force. It could be observed that the Schiller–Naumann model does not yield in a suffusive behaviour while the extended models show significant particle migration. Thereby, increasing the impact of the void fraction on the drag force results in stronger particle migration. These results reveal the need for good validation techniques. They indicate how the drag force correlation can be adapted to depict the correct particle migration behaviour.  相似文献   

Updated predictive equations for broadband (0.01–10 s) horizontal response spectra and peak ground motions,based on a global dataset of digital acceleration records     

Carlo Cauzzi  Ezio Faccioli  Manuela Vanini  Aldo Bianchini 《Bulletin of Earthquake Engineering》2015,13(6):1587-1612

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Using sulfur and oxygen isotope data for sulfide oxidation assessment in the Freiberg polymetallic sulfide mine     

Manuela Junghans  Marion Tichomirowa   《Applied Geochemistry》2009,24(11):2034-2050

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Oxygen isotope evidence for sorption of molecular oxygen to pyrite surface sites and incorporation into sulfate in oxidation experiments     

Marion Tichomirowa  Manuela Junghans 《Applied Geochemistry》2009,24(11):2072-2092

Experiments were conducted to investigate (i) the rate of O-isotope exchange between SO₄ and water molecules at low pH and surface temperatures typical for conditions of acid mine drainage (AMD) and (ii) the O- and S-isotope composition of sulfates produced by pyrite oxidation under closed and open conditions (limited and free access of atmospheric O₂) to identify the O source/s in sulfide oxidation (water or atmospheric molecular O₂) and to better understand the pyrite oxidation pathway. An O-isotope exchange between SO₄ and water was observed over a pH range of 0–2 only at 50 °C, whereas no exchange occurred at lower temperatures over a period of 8 a. The calculated half-time of the exchange rate for 50 °C (pH = 0 and 1) is in good agreement with former experimental data for higher and lower temperatures and excludes the possibility of isotope exchange for typical AMD conditions (T  25 °C, pH  3) for decades.Pyrite oxidation experiments revealed two dependencies of the O-isotope composition of dissolved sulfates: O-isotope values decreased with longer duration of experiments and increasing grain size of pyrite. Both changes are interpreted as evidence for chemisorption of molecular O₂ to pyrite surface sites. The sorption of molecular O₂ is important at initial oxidation stages and more abundant in finer grained pyrite fractions and leads to its incorporation in the produced SO₄. The calculated bulk contribution of atmospheric O₂ in the dissolved SO₄ reached up to 50% during initial oxidation stages (first 5 days, pH 2, fine-grained pyrite fraction) and decreased to less than 20% after about 100 days. Based on the direct incorporation of molecular O₂ in the early-formed sulfates, chemisorption and electron transfer of molecular O₂ on S sites of the pyrite surface are proposed, in addition to chemisorption on Fe sites. After about 10 days, the O of all newly-formed sulfates originates only from water, indicating direct interaction of hydroxyls from water with S at the anodic S pyrite surface site. Then, the role of molecular O₂ is as proposed in previous studies: acting as electron acceptor only at the cathodic Fe pyrite surface site for oxidation of Fe(II) to Fe(III).  相似文献   

Geomorphological mapping for the valorization of the alpine environment. A methodological proposal tested in the Loana Valley (Sesia Val Grande Geopark,Western Italian Alps)   总被引：1，自引：1，他引：0  

Irene Bollati  Beatrice Crosa Lenz  Enrico Zanoletti  Manuela Pelfini 《山地科学学报》2017,14(6):1023-1038

Geomorphological mapping plays a key role in landscape representation: it is the starting point for many applications and for the realization of thematic maps, such as hazard and risk maps, geoheritage and geotourism maps. Traditional geomorphological maps are useful for scientific purposes but they need to be simplified for different aims as management and education. In tourism valorization, mapping of geomorphological resources (i.e., geosites, and geomorphosites), and of geomorphic evidences of past hazardous geomorphological events, is important for increasing knowledge about landscape evolution and active processes, potentially involving geomorphosites and hiking trails. Active geomorphosites, as those widespread in mountain regions, testify the high dynamicity of geomorphic processes and their link with climatic conditions. In the present paper, we propose a method to produce and to update cartographic supports (Geomorphological Boxes) realized starting from a traditional geomorphological survey and mapping. The Geomorphological Boxes are geomorphological representation of single, composed or complex landforms drawn on satellite images, using the official Italian geomorphological legend (ISPRA symbols). Such cartographic representation is also addressed to the analysis (identification, evaluation and selection) of Potential Geomorphosites and Geotrails. The method has been tested in the upper portion of the Loana Valley (Western Italian Alps), located within the borders of the Sesia Val Grande Geopark, recognized by UNESCO in 2013. The area has a good potential for geotourism and for educational purposes. We identified 15 Potential Geomorphosites located along 2 Geotrails; they were ranked according to specific attributes also in relation with a Reference Geomorphosite located in the Loana hydrographic basin and inserted in official national and regional databases of geosites (ISPRA; Regione Piemonte). Finally, the ranking of Potential Geomorphosites allowed to select the most valuable ones for valorization or geoconservation purposes. In this framework, examples of Geomorphological Boxes are proposed as supports to geo-risk education practices.  相似文献