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排序方式: 共有48条查询结果,搜索用时 15 毫秒
41.
F.J. Gallego F. Batista C. Rocha S. Mubareka 《International journal of geographical information science》2013,27(12):2051-2069
This article describes and compares six disaggregation methods used to produce a dasymetric population density grid of the European Union at a 100 m resolution. Population data were initially available at commune level. The main ancillary information source was CORINE land cover, a land cover map distributed by the European Environment Agency. Information from the Eurostat point survey, land use/cover area frame survey, was also integrated in the parameter estimation of some of the approaches tested. Accurate population data for 1 km cell grids were provided by the Statistical Offices of Austria, Denmark, Finland, the Netherlands, Northern Ireland, Estonia and Sweden. These data provided the basic reference to quantify the accuracy of each method. The best results were obtained with a modified version of the limiting variable method (Eicher, C. and Brewer, C., 2001. Dasymetric mapping and areal interpolation: implementation and evaluation. Cartography and Geographic Information Science, 28, 125–138) that could be implemented, thanks to the national reference grids. For other methods the parameters could be estimated without using the reference grids; among them a method based on logit regression gave the best results. Compared with the traditional choropleth maps that represent a homogeneous density in each commune, the accuracy improvement of the disaggregated maps ranged between 20% and 67% (between 46% and 67% for the best method). 相似文献
42.
Eduardo Salamuni Hans Dirk Ebert Mauricio da Silva Borges Yociteru Hasui Joo Batista Sena Costa Riad Salamuni 《Journal of South American Earth Sciences》2003,15(8):901-910
The Curitiba Basin, Paraná, lies parallel to the west side of the Serra do Mar range and is part of a continental rift near the Atlantic coast of southeastern Brazil. It bears unconsolidated and poorly consolidated sediments divided in two formations: the lower Guabirotuba Formation and the overlying Tinguis Formation, both developed over Precambrian basement. Field observations, water well drill cores, and interpretations of satellite images lead to the inference that regional tectonic processes were responsible for the origin of the Basin in the continental rift context and for morphotecatonic evolution through block tilting, dissection, and erosion. The structural framework of the sediments and the basement is characterized by NE–SW-trending normal faults (extensional tectonic D1 event) reactivated by NE–SW-trending strike–slip and reverse oblique faults (younger transtensional tectonic D2′ to transpressional tectonic D2″ event). This tectonic event, which started in the Paleogene and controlled the basin geometry, began as a halfgraben and was later reactivated as a pull-apart basin. D2 is a neotectonic event that controls the current morphostructures. The Basin is connected to the structural rearrangement of the South American platform, which underwent a generalized extensional or trantensional process and, in late Oligocene, changed to a compressional to transpressional regime. 相似文献
43.
Tiago Mane Nunes Valéria Cristina F. Barbosa João Batista C. Silva 《Pure and Applied Geophysics》2008,165(9-10):1891-1911
We present a total-field anomaly inversion method to determine both the basement relief and the magnetization direction (inclination and declination) of a 2D sedimentary basin presuming negligible sediment magnetization. Our method assumes that the magnetic intensity contrast is constant and known. We use a nonspectral approach based on approximating the vertical cross section of the sedimentary basin by a polygon, whose uppermost vertices are forced to coincide with the basin outcrop, which are presumably known. For fixed values of the x coordinates our method estimates the z coordinates of the unknown polygon vertices. To obtain the magnetization direction we assume that besides the total-field anomaly, information about the basement’s outcrops at the basin borders and the basement depths at a few points is available. To obtain stable depth-to-basement estimates we impose overall smoothness and positivity constraints on the parameter estimates. Tests on synthetic data showed that the simultaneous estimation of the irregular basement relief and the magnetization direction yields good estimates for the relief despite the mild instability in the magnetization direction. The inversion of aeromagnetic data from the onshore Almada Basin, Brazil, revealed a shallow, eastward-dipping basement basin. 相似文献
44.
V.F. Andrioli B.R. Clemesha P.P. Batista N.J. Schuch 《Journal of Atmospheric and Solar》2009,71(17-18):1864-1876
We compare meteor radar measurements of the MLT region winds at Santa Maria, Brazil (29.7°S, 53.8°W) with the Horizontal Neutral Wind Model (HWM-93) and the Global Scale Wave Model (GSWM-00). The observed annual variation of the prevailing zonal wind disagrees in some respects with the HWM-93 model. Also, the zonal diurnal tide amplitude shows an annual variation, whereas that of the GSWM-00 is semiannual, and its vertical wavelength is smaller than that suggested by the model. The observed semidiurnal tide shows seasonal and inter-annual variations and the phase is evanescent during almost the whole year. 相似文献
45.
During an equatorial campaign called COPEX (Conjugate Point Equatorial Experiment) ionosondes at a pair of conjugate stations in Brazil were operated for 2 months in 2002. One expected the sporadic-E (Es) layers to be rather similar at the conjugate locations. However, there were significant differences in the Es, particularly in the part of the Es trace that extends above the blanketing frequency. Considerations of the ambient conditions at the conjugate locations indicate that relatively small differences in parameters such as the tidal winds, electric fields, and background density gradients can significantly affect the structuring of the Es layer. 相似文献
46.
Application of Laser‐Induced Breakdown Spectroscopy and Hyperspectral Images for Direct Evaluation of Chemical Elemental Profiles of Coprolites
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Marco Aurélio Sperança Francisco Wendel Batista de Aquino Marcelo Adorna Fernandes Alejandro Lopez‐Castillo Renato Lajarim Carneiro Edenir Rodrigues Pereira‐Filho 《Geostandards and Geoanalytical Research》2017,41(2):273-282
This study demonstrates the application of laser‐induced breakdown spectroscopy (LIBS) and hyperspectral imaging to the investigation of coprolite and fossil samples. Solid samples from the Permian (seven coprolites and one fossil), Cretaceous (one coprolite) and Oligo‐Miocene (two coprolites) periods were directly analysed, and emission spectra from 186 to 1042 nm were obtained in several areas covering coprolite/fossil and rock material. Initial exploratory analyses were performed using principal component analysis with the data set normalised by the norm (Euclidean norm = 1). After identification and selection of emission lines of eleven elements (Al, Ca, Cr, Fe, K, Mg, Mn, Na, Ni, P and Si), the signals were normalised again by the relative intensity of the selected element. Phosphorus was identified mainly in the coprolites, while K and Na were primarily found in the rock material. In several cases, there was a positive correlation between Ca and P. A sample from the Oligo‐Miocene series was also analysed using inductively coupled plasma‐optical emission spectrometry (ICP‐OES) (rock and coprolites were analysed separately). Based on the quantitative results from ICP‐OES, it was confirmed that the tendency was the same as that observed with the results obtained from LIBS directly in the solid sample. 相似文献
47.
The main goal of this paper is to revisit the lost siblings of the Sun candidates within 100 pc. The solar siblings should have some similar characteristics as their ages, chemical compositions and kinematics properties. Considering their chemical compositions, age and kinematics properties only three potential candidates have been found in the literature: HD28676, HD83423 and HD175740. The first two stars are mentioned by
[Brown et al., 2010] and [Bobylev et al., 2011], respectively. HD175740 is, to our knowledge, the first giant to be proposed as potential candidate. 相似文献
48.
Cleivison Souza de Jesus Andre Luis Batista Ribeiro Christine Cordula Dantas 《Astronomische Nachrichten》2024,345(1):e220081
In this work, we study how to improve well-known techniques for detecting progenitors/descendants of galaxies, such as the NDpredict program, when applied to galaxies in clusters. The improvement of this particular method is based on the use of the red sequence of galaxies in those environments. Objects close to the red sequence in the color and magnitude diagram are more likely to belong to the cluster. This defines a probability scale which is then combined with the one generated by NDpredict. This procedure is optimized for the study of galaxies in clusters over different epochs. Our main result is that, for a sample composed of clusters, with masses greater than , selected from the IllustrisTNG simulations (namely, the TNG100 runs). In of the cases (i.e., systems), we obtain better performance with the red sequence method in comparison to the original NDpredict, and the average gain obtained is in the identification of descendants for this sample of cluster galaxies. 相似文献