The PMS δ Scuti star PDS2     

M. Marconi  V. Ripepi  S. Bernabei  A. Ruoppo  M. J. P. F. G. Monteiro  J. P. Marques  F. Palla  S. Leccia 《Astrophysics and Space Science》2010,328(1-2):109-111

The Herbig Ae star PDS2 was found to pulsate as a Pre-Main-Sequence delta Scuti star on the basis of R.E.M. telescope photometry. From the frequency analysis we have found four significant pulsation frequencies. We discuss these results and their interpretation through the adoption of nonradial pulsation models, deriving the first information on the intrinsic properties of this young star.  相似文献   

Water-Tank Studies of Separating Flow Over Rough Hills   总被引：1，自引：1，他引：0  

J. B. R. Loureiro  A. S. Monteiro  F. T. Pinho  A. P. Silva Freire 《Boundary-Layer Meteorology》2008,129(2):289-308

The present work investigates the lower boundary condition for flows over a steep, rough hill. Simple asymptotic arguments together with the mixing-length hypothesis are used to derive a local analytical solution that is tested against three different flow conditions. In all, 36 velocity profiles are compared with the proposed expression. The experiments were carried out in a water channel and velocity measurements were made through laser Doppler anemometry. The extent of separated flow was made to vary as a function of the roughness and the Reynolds number. The analysis includes regions of attached as well as separated flow. In particular, the solution of Stratford is studied at the points of separation and re-attachment and found to apply equally well in rough walls.  相似文献   

Inter-comparison of the g-, f- and p-modes calculated using different oscillation codes for a given stellar model     

A. Moya  J. Christensen-Dalsgaard  S. Charpinet  Y. Lebreton  A. Miglio  J. Montalbán  M. J. P. F. G. Monteiro  J. Provost  I. W. Roxburgh  R. Scuflaire  J. C. Suárez  M. Suran 《Astrophysics and Space Science》2008,316(1-4):231-249

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A Rigid Particle Model for Rock Fracture Following the Voronoi Tessellation of the Grain Structure: Formulation and Validation     

N. Monteiro Azevedo  M. Candeias  F. Gouveia 《Rock Mechanics and Rock Engineering》2015,48(2):535-557

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Contributions of hydrogeophysics to the hydrogeological conceptual model of the Albufeira-Ribeira de Quarteira coastal aquifer in Algarve,Portugal   总被引：1，自引：0，他引：1  

Alain P. Francés  Elsa C. Ramalho  Judite Fernandes  Michel Groen  Rui Hugman  Mohamed A. Khalil  Joel De Plaen  Fernando A. Monteiro Santos 《Hydrogeology Journal》2015,23(7):1553-1572

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Effect of artificial reefs (southern Portugal) on sediment–water transport of nutrients: Importance of the hydrodynamic regime     

M. Falco  M.N. Santos  T. Drago  D. Serpa  C. Monteiro 《Estuarine, Coastal and Shelf Science》2009,83(4):451-459

The present study investigates the differences between nutrient fluxes and particulate organic matter within an artificial reef system (AR) deployed in August 2002 off Faro (Algarve, Southern Portugal) and in a non-reef area (NRA), and how fluxes and suspended material may be affected by the hydrodynamic regime. Surveys to collect sediment cores, suspended/settled particles and overlying water samples were carried out by divers, from March (2006) to October (2007) in AR and NRA. Sediment cores and settled particles were collected to determine grain size, organic and inorganic carbon, nitrogen and phosphorus content. Overlying water and pore water samples were analysed for ammonium, nitrite, nitrate, phosphate, silicate, dissolved organic nitrogen, dissolved organic phosphorus and chlorophyll a. Results from the period studied showed that: (1) the benthic export of dissolved N, P and Si was 2–3 times higher at AR; (2) the particulate organic carbon (POC), nitrogen (PON) and phosphorus (POP) in suspended/settled particles were about 1.5 times higher at AR; (3) at both AR and NRA, the benthic export of dissolved N, P and Si, during a calm weather period, was 2–4 times higher than during or immediately after a storm event; and (4) at both sites, particulate organic compounds (POC, PON and POP) increased about 20 times during a storm event. These findings suggest that both the nutrients transport from sediment to water column and the quantity/quality of suspended/settled particles were highly dependent on the existence of reef structures and on the hydrodynamic regime.  相似文献   

Geoweb Services for Sharing Modelling Results in Biodiversity Networks   总被引：1，自引：0，他引：1  

Karla Donato Fook  Antônio Miguel Vieira Monteiro  Gilberto Câmara  Marco Antônio Casanova  Silvana Amaral 《Transactions in GIS》2009,13(4):379-399

Biodiversity researchers in different institutions deal with predictive models for species distribution. These models are useful for biodiversity conservation policies. Species distribution modelling tools need large datasets from different sources and use many algorithms. To improve biodiversity science, scientists need to share models, data and results, and should be able to reproduce experiments from others. This article presents a geoweb service architecture that supports sharing of modelling results and enables researchers to perform new modelling experiments. We show the feasibility of the proposed architecture by developing a set of prototype services, called Web Biodiversity Collaborative Modelling Services – WBCMS. They provide a set of geospatial web services that support the sharing of species distribution models. The article includes an example of a model instance that explains the WBCMS prototype. We believe that WBCMS shows how to set up a cooperative research network on biodiversity research.  相似文献   

Seismic analysis of the second ionization region of helium in the Sun – I. Sensitivity study and methodology     

Mário J. P. F. G. Monteiro  Michael J. Thompson 《Monthly notices of the Royal Astronomical Society》2005,361(4):1187-1196

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Isotope geochemistry of the mafic dikes from the Vazante nonsulfide zinc deposit, Brazil   总被引：2，自引：0，他引：2  

M. Babinski  L.V.S. Monteiro  A.H. Fetter  J.S. Bettencourt  T.F. Oliveira   《Journal of South American Earth Sciences》2005,18(3-4):293-304

The Vazante Group, located in the northwestern part of Minas Gerais, hosts the most important zinc mine in Brazil, the Vazante Mine, which represents a major known example of a hypogene nonsulfide zinc deposit. The main zinc ore is represented by willemite and differs substantially from other deposits of the Vazante-Paracatu region, which are sulfide-dominated zinc-lead ore. The age of the Vazante Group and the hosted mineralization is disputable. Metamorphosed mafic dikes (metabasites) that cut the metasedimentary sequence and are affected by hydrothermal processes recently were found and may shed light on the geochronology of this important geological unit. Zircon crystals recovered from the metabasites are xenocrystic grains that yield U–Pb conventional ages ranging from 2.1 to 2.4 Ga, so the basement of the Vazante Group is Paleoproterozoic or has metasedimentary rocks whose source area was Paleoproterozoic. Pb isotopes determined for titanite separated from the metabasites have common, nonradiogenic Pb compositions, which prevents determination of their crystallization age. However, the Pb signatures observed for the titanite crystals are in agreement with those determined for galena from the carbonate-hosted Zn–Pb deposits hosted by the Vazante Group, including galena from minor sulfide ore bodies of the Vazante deposit. These similarities suggest that the metalliferous fluids that affected the metabasites may have been those responsible for galena formation, which could imply a similar lead source for both nonsulfide and sulfide zinc deposits in the Vazante–Paracatu district. This common source could be related to deep-seated, basin-derived, metalliferous fluids associated with a long-lived hydrothermal system related to diagenesis and deformation of the Vazante Group during the Neoproterozoic.  相似文献   

Are some of the deep crustal conductive features found in SW Iberia caused by graphite?   总被引：1，自引：0，他引：1  

Fernando A. Monteiro Santos  António Mateus  Jaume Pous 《Earth and Planetary Science Letters》2002,201(2):353-367

Recent results obtained from two-dimensional inversion of magnetotelluric (MT) data acquired in SW Iberia reveal high-conductive features at the middle-lower levels of the crust. The top of these anomalous structures correlates very well with the depth (10-13 km) of an important seismic interface that has been interpreted as a regional detachment horizon. Very shallow and relatively narrow conductors in the Ossa Morena Zone appear to correspond to small-scale fluid-deposited graphite systems in the preorogenic metasedimentary sequences. Some of the midcrustal conductors can be ascribed to graphite-bearing thrust zones, the formation of graphite with variable crystallinity being a consequence of Variscan shearing processes. Deep-seated conductors are tentatively interpreted as a result of relatively continuous, highly crystalline grain-boundary graphite films presumably preserved in basement, granulite(?) rocks. Assuming that graphite occurs as interconnected films, calculations indicate that a fraction of 0.006-0.02% of this accessory mineral is enough to explain the range of the electrical resistivity estimated on the basis of MT models. The role of graphite on the thermal behaviour of the crust is also discussed. The results show that low contents of graphite do not significantly change the thermal behaviour of earth materials.  相似文献