Study of the variability of the Delta Scuti stars     

Michele Bossi  Gianantonio Guerrero  Luciano Mantegazza  Marco Scardia 《Astrophysics and Space Science》1981,79(2):463-468

Photoelectric observations of the suspected Delta-Scuti star HR 5492 are given. The present data do not show any light variation greater than 0.01 mag. In spite of the very small light variations, the data analysis shows the presence of two periodicities, which are statistically significant. While the longest period (1. _. ^d 296) cannot be justified with the present data, the shorter one (0. _. ^d 044) is in excellent agreement with the hypothesis of an F4V star that is radially pulsating in the fundamental mode, even if this star is well outside the cold border of the instability strip.  相似文献   

Persistent organic pollutants in rough-toothed dolphins (Steno bredanensis) sampled during an unusual mass stranding event   总被引：1，自引：0，他引：1  

Struntz WD  Kucklick JR  Schantz MM  Becker PR  McFee WE  Stolen MK 《Marine pollution bulletin》2004,48(1-2):164-173

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Determination of masses of the central black holes in NGC 524 and 2549 using laser guide star adaptive optics     

Davor Krajnovi&#;  Richard M. McDermid  Michele Cappellari  Roger L. Davies 《Monthly notices of the Royal Astronomical Society》2009,399(4):1839-1857

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On the Transits of Solar System Objects in the Forthcoming Planck Mission: Data Flagging and Coeval Multi-Frequency Observations     

Michele Maris  Carlo Burigana 《Earth, Moon, and Planets》2009,105(2-4):81-88

In the context of current and future microwave surveys mainly dedicated to the accurate mapping of Cosmic Microwave Background (CMB), mm and sub-mm emissions from Solar System will represent a potential source of contamination as well as an opportunity for new Solar System studies. In particular, the forthcoming ESA Planck mission will be able to observe the point-like thermal emission from planets and some large asteroids as well as the diffused Zodiacal Light Emission (ZLE). After a brief introduction to the field, we focus on the identification of Solar System discrete objects in the Planck time ordered data.  相似文献   

Structural control over equilibrium silicon and oxygen isotopic fractionation: A first-principles density-functional theory study     

Merlin Méheut  Michele Lazzeri  Etienne Balan  Francesco Mauri 《Chemical Geology》2009,258(1-2):28-37

Isotopic fractionation factors for oxygen and silicon in selected silicates (quartz, enstatite, forsterite, lizardite, kaolinite) are calculated using first-principles methods based on density-functional theory. Good agreement between theory and experiment is found in the case of oxygen. In the case of silicon, agreement and differences with existing estimates of equilibrium fractionation factors are discussed. The relationship between silicon and oxygen fractionation factors, silicate polymerization degree and chemical composition is studied and compared with previous semi-empirical models.  相似文献   

Saturn’s high degree magnetic moments: Evidence for a unique planetary dynamo     

Hao Cao  Christopher T. Russell  Johannes Wicht  Ulrich R. Christensen  Michele K. Dougherty 《Icarus》2012,221(1):388-394

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Exploring the infrared/radio correlation at high redshift     

Edo Ibar  Michele Cirasuolo  Rob Ivison  Philip Best  Ian Smail  y Biggs  Chris Simpson  Jim Dunlop  Omar Almaini  Ross McLure  Sebastien Foucaud  Steve Rawlings 《Monthly notices of the Royal Astronomical Society》2008,386(2):953-962

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Did the “Autochthonous” European foreland of Corsica Island (France) experience Alpine subduction?     

Maria Di Rosa  Chiara Frassi  Michele Marroni  Francesca Meneghini  Luca Pandolfi 《地学学报》2020,32(1):34-43

Despite the important role played by the Sardinia‐Corsica block in the reconstruction of the Western Mediterranean geodynamics, the extent of involvement of the “Autochthonous” European margin exposed in Corsica (France) (i.e., Hercynian Corsica) in the Alpine orogeny remains uncertain. Stratigraphic and sedimentological studies in the post‐Variscan deposits on the Hercynian Corsica are scarce and even scarcer are the structural and metamorphic constraints. To face these uncertainties, we present new stratigraphic, structural and metamorphic data from the area of Razzo Bianco, Central Corsica, where a complete sequence belonging to the European continental margin is exposed. Field and structural investigations demonstrate that the sequence represents the easternmost edge of the downgoing European plate. Metamorphic studies on the Eocene deposits indicate that the margin was buried at depth up to blueschist facies conditions and, subsequently, it was progressively exhumed mainly through the activation of oblique top‐to‐the NW shear zones.  相似文献   

Spatial and diurnal distribution of invertebrate and fish fauna of a Zostera marina bed and nearby unvegetated sediments in Damariscotta River, Maine (USA)     

Johanna Mattila  Glen Chaplin  Michele R. Eilers  Kenneth L. Heck Jr.  Jonathan P. O'Neal  John F. Valentine 《Journal of Sea Research》1999,41(4):209

Fish, epibenthos and macroinfauna were collected in a Zostera marina bed and nearby unvegetated sediments in the estuary of the Damariscotta River, on the mid-coast of Maine. Samples of epibenthic fauna and fish were collected at low tides both during day and night, and samples of infauna at low tides during the day. The mean density of Zostera shoots in the study area was 335 m⁻². Abundance and species number of fish were greater at night than during the day and greater in eelgrass beds (Z. marina) than in unvegetated habitats. Daytime fish collections were dominated by Atlantic silversides (Medinia medinia), while juvenile winter flounder (Pseudopleuronectes americanus) dominated night collections. Also Zostera-associated epifaunal abundances and number of species were significantly higher at night than during the day. Mysis stenolepis, Idotea balthica and Littorina obtusata were dominant species in the epifauna samples. Of the total of 37 invertebrate species encountered, only five occurred both in the infaunal and epifaunal samples. Nineteen different taxa were collected from the benthic core samples. The most abundant invertebrate infaunal taxa were sipunculids, the polychaete Nereis virens, and oligochaetes. Infaunal invertebrate abundances and species diversity were significantly higher in eelgrass beds than in unvegetated sediments. The abundance and number of species of benthic invertebrates were also positively correlated to seagrass biomass. Community diversity values (H′) were relatively low but fit well in the general pattern of decreasing diversity towards northern latitudes.  相似文献   

Long‐term sediment yield from a small catchment in southern Brazil affected by land use and soil management changes          下载免费PDF全文

Jean P.G. Minella  Gustavo H. Merten  Claúdia A.P. Barros  Rafael Ramon  Alexandre Schlesner  Robin T. Clarke  Michele Moro  Leandro Dalbianco 《水文研究》2018,32(2):200-211

Sediments produced from eroding cultivated land can cause on‐site and off‐site effects that cause considerable economic and social impacts. Despite the importance of soil conservation practices (SCP) for the control of soil erosion and improvements in soil hydrological functions, limited information is available regarding the effects of SCP on sediment yield (SY) at the catchment scale. This study aimed to investigate the long‐term relationships between SY and land use, soil management, and rainfall in a small catchment. To determine the effects of anthropogenic and climatic factors on SY, rainfall, streamflow, and suspended sediment concentration were monitored at 10‐min intervals for 14 years (2002–2016), and the land use and soil management changes were surveyed annually. Using a statistical procedure to separate the SY effects of climate, land use, and soil management, we observed pronounced temporal effects of land use and soil management changes on SY. During the first 2 years (2002–2004), the land was predominantly cultivated with tobacco under a traditional tillage system (no cover crops and ploughed soil) using animal traction. In that period, the SY reached approximately 400 t·km^?2·year^?1. From 2005 to 2009, a soil conservation programme introduced conservation tillage and winter cover crops in the catchment area, which lowered the SY to 50 t·km^?2·year^?1. In the final period (2010–2016), the SCP were partially abandoned by farmers, and reforested areas increased, resulting in an SY of 150 t·km^?2·year^?1. This study also discusses the factors associated with the failure to continue using SCP, including structural support and farmer attitudes.  相似文献