The transition between ‘orogenic’ and ‘anorogenic’ magmatism in the western Mediterranean area: the Middle Miocene volcanic rocks of Isola del Toro (SW Sardinia,Italy)     

Michele Lustrino  Vincenzo Morra  Lorenzo Fedele  Marcello Serracino 《地学学报》2007,19(2):148-159

The Isola del Toro is a small island (∼1 km²) about 5 nautical miles SW of Sardinia entirely made up of mildly alkaline sodic evolved rocks (benmoreites and trachytes) related to each other by fractionation processes. ⁴⁰Ar/³⁹Ar dating of an anorthoclase mineral separate from a trachyte gave an age of 11.83 ± 0.10 Ma. This age estimate falls within an interval previously considered a‐magmatic in Sardinia. The results of this study shift the beginning of the Middle Miocene–Quaternary anorogenic volcanism of Sardinia back to the Late Serravalian. The transition between orogenic and anorogenic activity in Sardinia is markedly different from that recorded in the rest of the circum‐Mediterranean area, where this transition is much more gradual, both in time and in terms of magma composition. On the other hand, the transition between orogenic and anorogenic magmatism in Sardinia is rather sharp and lacks hybrid compositions. The Isola del Toro volcanic rocks represent the first anorogenic products produced during the opening of the western Mediterranean Sea.  相似文献   

Orbit determination with the two-body integrals: III     

G. F. Gronchi  G. Baù  S. Marò 《Celestial Mechanics and Dynamical Astronomy》2015,123(2):105-122

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Satellite kinematics – II. The halo mass–luminosity relation of central galaxies in SDSS     

Surhud More †  Frank C. van den Bosch  Marcello Cacciato  H. J. Mo  Xiaohu Yang  Ran Li 《Monthly notices of the Royal Astronomical Society》2009,392(2):801-816

The kinematics of satellite galaxies reflect the masses of the extended dark matter haloes in which they orbit, and thus shed light on the mass–luminosity relation (MLR) of their corresponding central galaxies. In this paper, we select a large sample of centrals and satellites from the Sloan Digital Sky Survey and measure the kinematics (velocity dispersions) of the satellite galaxies as a function of the r -band luminosity of the central galaxies. Using the analytical framework presented in More, van den Bosch & Cacciato, we use these data to infer both the mean and the scatter of the MLR of central galaxies, carefully taking account of selection effects and biases introduced by the stacking procedure. As expected, brighter centrals on average reside in more massive haloes. In addition, we find that the scatter in halo masses for centrals of a given luminosity,  σ_{log  M}   , also increases with increasing luminosity. As we demonstrate, this is consistent with  σ_{log  L}   , which reflects the scatter in the conditional probability function   P ( L _c| M )  , being independent of halo mass. Our analysis of the satellite kinematics yields  σ_{log  L} = 0.16  ±  0.04  , in excellent agreement with constraints from clustering and group catalogues, and with predictions from a semi-analytical model of galaxy formation. We thus conclude that the amount of stochasticity in galaxy formation, which is characterized by  σ_{log  L}   , is well constrained, independent of halo mass and in a good agreement with current models of galaxy formation.  相似文献   

Physical properties of (2) Pallas     

Benoît Carry  Christophe Dumas  Jérôme Berthier  Stéphane Erard  Jack D. Drummond  Marcello Fulchignoni 《Icarus》2010,205(2):460-472

Ground-based high angular-resolution images of asteroid (2) Pallas at near-infrared wavelengths have been used to determine its physical properties (shape, dimensions, spatial orientation and albedo distribution).We acquired and analyzed adaptive optics (AO) J/H/K-band observations from Keck II and the Very Large Telescope taken during four Pallas oppositions between 2003 and 2007, with spatial resolution spanning 32-88 km (image scales 13-20 km/pixel). We improve our determination of the size, shape, and pole by a novel method that combines our AO data with 51 visual light-curves spanning 34 years of observations as well as archived occultation data.The shape model of Pallas derived here reproduces well both the projected shape of Pallas on the sky (average deviation of edge profile of 0.4 pixel) and light-curve behavior (average deviation of 0.019 mag) at all the epochs considered. We resolved the pole ambiguity and found the spin-vector coordinates to be within 5° of [longitude, latitude] = [30°, −16°] in the Ecliptic J2000.0 reference frame, indicating a high obliquity of about 84°, leading to high seasonal contrast. The best triaxial-ellipsoid fit returns ellipsoidal radii of , and . From the mass of Pallas determined by gravitational perturbation on other minor bodies , [Michalak, G., 2000. Astron. Astrophys. 360, 363-374], we derive a density of significantly different from the density of C-type (1) Ceres of [Carry, B., Dumas, C., Fulchignoni, M., Merline, W.J., Berthier, J., Hestroffer, D., Fusco, T., Tamblyn, P., 2008. Astron. Astrophys. 478 (4), 235-244]. Considering the spectral similarities of Pallas and Ceres at visible and near-infrared wavelengths, this may point to fundamental differences in the interior composition or structure of these two bodies.We define a planetocentric longitude system for Pallas, following IAU guidelines. We also present the first albedo maps of Pallas covering ∼80% of the surface in K-band. These maps reveal features with diameters in the 70-180 km range and an albedo contrast of about 6% with respect to the mean surface albedo.  相似文献   

An integrated evaluation of thirteen modelling solutions for the generation of hourly values of air relative humidity     

Simone Bregaglio  Marcello Donatelli  Roberto Confalonieri  Marco Acutis  Simone Orlandini 《Theoretical and Applied Climatology》2010,102(3-4):429-438

The availability of hourly air relative humidity (HARH) data is a key requirement for the estimation of epidemic dynamics of plant fungal pathogens, in particular for the simulation of both the germination of the spores and the infection process. Most of the existing epidemic forecasting models require these data as input directly or indirectly, in the latter case for the estimation of leaf wetness duration. In many cases, HARH must be generated because it is not available in historical series and when there is the need to simulate epidemics either on a wide scale or with different climate scenarios. Thirteen modelling solutions (MS) for the generation of this variable were evaluated, with different input requirements and alternative approaches, on a large dataset including several sites and years. A composite indicator was developed using fuzzy logic to compare and to evaluate the performances of the models. The indicator consists of four modules: Accuracy, Correlation, Pattern and Robustness. Results showed that when available, daily maximum and minimum air relative humidity data substantially improved the estimation of HARH. When such data are not available, the choice of the MS is crucial, given the difference in predicting skills obtained during the analysis, which allowed a clear detection of the best performing MS. This study represents the first step of the creation of a robust modelling chain coupling the MS for the generation of HARH and disease forecasting models, including the systematic validation of each step of the simulation.  相似文献   

Increasing the detail of European land use/cover data by combining heterogeneous data sets     

Konštantín Rosina  Filipe Batista e Silva  Pilar Vizcaino  Mario Marín Herrera  Sérgio Freire  Marcello Schiavina 《International Journal of Digital Earth》2020,13(5):602-626

ABSTRACT

Data on land use and land cover (LULC) are a vital input for policy-relevant research, such as modelling of the human population, socioeconomic activities, transportation, environment, and their interactions. In Europe, CORINE Land Cover has been the only data set covering the entire continent consistently, but with rather limited spatial detail. Other data sets have provided much better detail, but either have covered only a fraction of Europe (e.g. Urban Atlas) or have been thematically restricted (e.g. Copernicus High Resolution Layers). In this study, we processed and combined diverse LULC data to create a harmonised, ready-to-use map covering 41 countries. By doing so, we increased the spatial detail (from 25 to one hectare) and the thematic detail (by seven additional LULC classes) compared to the CORINE Land Cover. Importantly, we decomposed the class ‘Industrial and commercial units’ into ‘Production facilities’, ‘Commercial/service facilities’ and ‘Public facilities’ using machine learning to exploit a large database of points of interest. The overall accuracy of this thematic breakdown was 74%, despite the confusion between the production and commercial land uses, often attributable to noisy training data or mixed land uses. Lessons learnt from this exercise are discussed, and further research direction is proposed.  相似文献   

Tensional crack development in physical models with inhomogeneities under load     

Janusz Niewiadomski  Marek Gòrski  Jan Kozák  Reviewer V. Červený  Reviewer J. Javornický 《Studia Geophysica et Geodaetica》1980,24(4):373-381

Summary The paper deals with a study of the mean stress field (_M) and its gradient (_M/x) in uniaxially loaded two-dimensional models of small thickness with respect to other dimensions, in which two inhomogeneities, e.g., a circular opening and a linear slit have been made. Particular attention was paid to the stress field development in the treated models durin gthe change of the mutual geometric configuration of both the inhomogeneities in question. The problem was analysed theoretically by means of Muskhelishvili's potentials of the two-dimensional theory of elasticity. To compare the results of calculations, the schlieren method was used to visualize and record the studied gradients of stress fields in physical models. The results of the calculations were calibrated by laboratory tests. In this way the individual model situations were classified from the point of view of their resistance to the applied load.  相似文献   

Quelques phénomènes accompagnant les phases préliminaires de manifestations éruptives du Vésuve et les relatives possibilités de prévisions     

G. Imbò 《Bulletin of Volcanology》1960,23(1):55-61

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A contribution to the analysis of the altimetry-gravimetry problem     

F. Sacerdote  F. Sansò 《Journal of Geodesy》1983,57(1-4):257-272

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Diesel oil and PCB-degrading psychrotrophic bacteria isolated from Antarctic seawaters (Terra Nova Bay, Ross Sea)   总被引：2，自引：0，他引：2  

Maria De  Domenico  Angelina Lo Giudice  Luigi Michaud  Marcello Saitta  Vivia Bruni 《Polar research》2004,23(2):141-146

Fifty-seven Antarctic marine bacteria were examined for their ability to degrade commercial diesel oil as the sole organic substrate at both 4 °C and 20 °C. Based on the preliminary screening, two isolates (B11 and B15) with high capacity to degrade diesel oil were selected and their biodegradation efficiency was quantified by gas chromatographic analysis. As expected for psychrotrophs, diesel oil biodegradation was slower at 4 °C than at 20 °C. The two strains also mineralized the C₂₈ n-paraffin octacosane at 20 °C and polychlorinated biphenyls (PCBs) at 4 °C and 20 °C.  相似文献