Optimizing interpolation of shoot density data from a Posidonia oceanica seagrass bed   总被引：1，自引：0，他引：1  

Michele Scardi  Lorenzo A. Chessa  Eugenio Fresi  Antonio Pais  & Simone Serra 《Marine Ecology》2006,27(4):339-349

A case study on the optimization of Posidonia oceanica density interpolation, using a data set from a large meadow at Porto Conte Bay (NW Sardinia, Italy), is presented. Ordinary point kriging, cokriging and a weighted average based on inverse square distance were used to interpolate density data measured in 36 sampling stations. The results obtained from different methods were then compared by means of a leave‐one‐out cross‐validation procedure. The scale at which interpolation was carried out was defined on the basis of the Hausdorff dimension of the variogram. Optimizing spatial scale and data points search strategy allowed obtaining more accurate density estimates independently of the interpolation method.  相似文献   

The bimodal rift-related Juscelândia volcanosedimentary sequence in central Brazil: Mesoproterozoic extension and Neoproterozoic metamorphism     

Renato Moraes  Reinhardt A. Fuck  Mrcio Martins Pimentel  Simone M.C.L. Gioia  Maria H.B.M. de Hollanda  Richard Armstrong 《Journal of South American Earth Sciences》2006,20(4):287-301

The Barro Alto Complex and Juscelândia volcanosedimentary sequence are exposed in the central part of the Neoproterozoic Brasília belt of central Brazil. The former is a large (approximately 150 km long), boomerang-shaped, mafic-ultramafic, layered complex formed by two different intrusions metamorphosed under granulite facies. These rocks are tectonically overlain by rocks of the Juscelândia volcanosedimentary sequence, represented mainly by biotite-gneiss and amphibolite, or amphibolite facies metamorphic equivalents of rhyolite and basalt, respectively. New SIMS U–Pb zircon data and Sm–Nd isochron data presented herein help clarify the igneous and metamorphic evolution of the Juscelândia volcanosedimentary sequence, as well as its relationship with the Barro Alto Complex. Zircon grains from two biotite gneisses were analyzed by SIMS (SHRIMP) and indicate Mesoproterozoic dates, approximately 1.28 Ga, interpreted as the time of bimodal volcanism in a tectonic setting transitional between a continental rift and an ocean basin. Metamorphism is constrained by Sm–Nd garnet-whole-rock isochrons for garnet amphibolite and pelitic schists of the Juscelândia sequence, as well as for clinopyroxene-garnet amphibolite and garnet granulite of the Barro Alto Complex, which give ages between 0.74 and 0.76 Ga, in agreement with SIMS dates for metamorphic zircon rims. These new data are significant, because they establish that a single metamorphic event affected both the Barro Alto Complex and the Juscelândia sequence. Based on these new data, we present a modified tectonic model for the Brasília belt.  相似文献   

Africa and intersecting politics     

AbdouMaliqu Simone 《Geoforum》2002,33(3):271-272

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Geochronology of granulites from the south Itabuna-Salvador-Curaçá Block,São Francisco Craton (Brazil): Nd isotopes and U–Pb zircon ages     

Jean-Jacques Peucat  Johildo Salomão Figueiredo Barbosa  Ivana Conceição de Araújo Pinho  Jean-Louis Paquette  Hervé Martin  C. Mark Fanning  Angela Beatriz de Menezes Leal  Simone Cruz 《Journal of South American Earth Sciences》2011,31(4):397-413

This work provides five new U–Pb zircon dating and the corresponding Nd isotope data for felsic granulites from the south Itabuna-Salvador-Curaçá Block (ISCB), in the São Francisco Craton, Brazil. Three major sets of felsic granulites can be recognised. The oldest set is tonalitic in composition and of TTG affinity. It is Archaean in age with magmatic zircon cores dated at 2675 ± 11 Ma by LA-ICPMS and up to ca 2.7–2.9 Ga by SHRIMP on an other sample. It exhibits epsilon Nd values between ?8 and ?11 at 2.1 Ga. This Nd signature is similar to that of granulites found in the western Archaean Jequié Block. Cartographically, this set of Archaean terrains represents at least 50% of the granulites in the studied area. The second set corresponds to a Palaeoproterozoic calc-alkaline tonalitic suite with zircon ages from 2019 ± 19 Ma to 2191 ± 10 Ma and epsilon Nd values between ?3 and ?4 at 2.1 Ga, corresponding partially to a newly formed crust. The third set of granulites is also Palaeoproterozoic. It is shoshonitic to monzonitic in composition and synchronous with the high grade metamorphism dated by metamorphic zircons at 2086 ± 7 Ma (average of five samples). The Nd isotope signature for this alkaline set is similar to that of the Palaeoproterozoic calc-alkaline one. Nd isotopes appear to be a very efficient tool to distinguish Archaean from Palaeoproterozoic felsic protoliths in granulitic suites of the Itabuna-Salvador-Curaçá Block (ISCB). Finally, the southern part of the ISCB is composed of a mixture of Archaean and Palaeoproterozoic protoliths, in similar amounts, suggesting that it was probably an active margin between 2.1 and 2.2 Ga located on the eastern border of the Archaean Jequié Block. A major crustal thickening process occurred at ca 2.09 Ga in the ISCB and seems significantly younger towards the west, in the Jequié granulites, where an average of 2056 ± 9 Ma is determined for the high grade event.  相似文献   

Multi-hazard assessment in Europe under climate change   总被引：2，自引：0，他引：2  

Giovanni Forzieri  Luc Feyen  Simone Russo  Michalis Vousdoukas  Lorenzo Alfieri  Stephen Outten  Mirco Migliavacca  Alessandra Bianchi  Rodrigo Rojas  Alba Cid 《Climatic change》2016,137(1-2):105-119

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Potential impacts of geothermal energy use and storage of heat on groundwater quality,biodiversity, and ecosystem processes     

Christian Griebler  Heike Brielmann  Christina M. Haberer  Sigrid Kaschuba  Claudia Kellermann  Christine Stumpp  Florian Hegler  David Kuntz  Simone Walker-Hertkorn  Tillmann Lueders 《Environmental Earth Sciences》2016,75(20):1391

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Relationship between irrigation water demand and yield of selected crops in Germany between 1902 and 2010: a modeling study     

Katrin Drastig  Judy Libra  Simone Kraatz  Hagen Koch 《Environmental Earth Sciences》2016,75(22):1427

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A GIS based planning support system for assessing financial feasibility of urban redevelopment     

Simone Z. Leao  Laurence Troy  Scott N. Lieske  Bill Randolph  Chris Pettit 《GeoJournal》2018,83(6):1373-1392

Urban densification trends combined with redevelopment increasingly moving away from large former industrial and transport sites toward existing town centres and corridors indicate redevelopment is becoming increasingly complex, difficult to plan for and undertake. The interplay between land and property markets and planning frameworks suggest city planners and urban researchers need new tools and methodologies to gain insights into ways to deliver effective responses. Despite the need, there is a limited availability of comprehensive models to fulfil the task. This paper describes a GIS-based tool to assess parcel-level financial feasibility and housing supply associated with urban redevelopment within a precinct. The tool incorporates existing and potential built form and parameters associated with the planning framework and land and property markets. Using a real case study in a workshop, tool performance was evaluated by professional urban planners in terms of its capacity to produce metrics and visualisations of potential scenarios of redevelopment. Results indicate the usefulness of the tool for emulating land market conditions and testing scenarios of planning regulation and market changes for strategic planning purposes.  相似文献   

An algorithm to resolve γ-rays from charged cosmic rays with DAMPE     

Zun-Lei Xu  Kai-Kai Duan  Zhao-Qiang Shen  Shi-Jun Lei  Tie-Kuang Dong  Fabio Gargano  Simone Garrappa  Dong-Ya Guo  Wei Jiang  Xiang Li  Yun-Feng Liang  Mario Nicola Mazziotta  Maria Fernanda Munoz Salinas  Meng Su  Valerio Vagelli  Qiang Yuan  Chuan Yue  Jing-Jing Zang  Ya-Peng Zhang  Yun-Long Zhang  Stephan Zimmer 《天文和天体物理学研究(英文版)》2018,(3)

The DArk Matter Particle Explorer(DAMPE),also known as Wukong in China,which was launched on 2015 December 17,is a new high energy cosmic ray and γ-ray satellite-borne observatory.One of the main scientific goals of DAMPE is to observe Ge V-Te V high energy γ-rays with accurate energy,angular and time resolution,to indirectly search for dark matter particles and for the study of high energy astrophysics. Due to the comparatively higher fluxes of charged cosmic rays with respect to γ-rays,it is challenging to identify γ-rays with sufficiently high efficiency,minimizing the amount of charged cosmic ray contamination. In this work we present a method to identify γ-rays in DAMPE data based on Monte Carlo simulations,using the powerful electromagnetic/hadronic shower discrimination provided by the calorimeter and the veto detection of charged particles provided by the plastic scintillation detector. Monte Carlo simulations show that after this selection the number of electrons and protons that contaminate the selected γ-ray events at～10 Ge V amounts to less than 1% of the selected sample.Finally,we use flight data to verify the effectiveness of the method by highlighting known γ-ray sources in the sky and by reconstructing preliminary light curves of the Geminga pulsar.  相似文献   

The particle background of the <Emphasis Type="Italic">X-IFU</Emphasis> instrument     

Simone Lotti  Teresa Mineo  Christian Jacquey  Silvano Molendi  Matteo D’Andrea  Claudio Macculi  Luigi Piro 《Experimental Astronomy》2017,44(3):371-385

In this paper we are going to review the latest estimates for the particle background expected on the X-IFU instrument onboard of the ATHENA mission. The particle background is induced by two different particle populations: the so called “soft protons” and the Cosmic rays. The first component is composed of low energy particles (< 100s keV) that get funnelled by the mirrors towards the focal plane, losing part of their energy inside the filters and inducing background counts inside the instrument sensitivity band. The latter component is induced by high energy particles (> 100 MeV) that possess enough energy to cross the spacecraft and reach the detector from any direction, depositing a small fraction of their energy inside the instrument. Both these components are estimated using Monte Carlo simulations and the latest results are presented here.  相似文献