Reply to the Discussion by Dillenburg et al. on “Evidence for a transgressive barrier within a regressive strandplain system: implications for complex response to environmental change” by Hein et al. (2013), Sedimentology 60, 469–502     

Christopher J. Hein  Duncan M. Fitzgerald  Antonio H. Da F. Klein  Marcio B. Albernaz  Joao Thadeu de Menezes  William J. Cleary 《Sedimentology》2014,61(7):2213-2217

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Morphology of low-redshift compact galaxy clusters – I. Shapes and radial profiles     

V. Strazzullo  M. Paolillo  G. Longo  E. Puddu  S. G. Djorgovski  R. R. De Carvalho  R. R. Gal 《Monthly notices of the Royal Astronomical Society》2005,359(1):191-210

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The diffusion model of cosmic-ray propagation     

J. C. Carvalho  D. ter Haar 《Astrophysics and Space Science》1979,61(1):19-44

We set up diffusion equations for the nuclear component of cosmic rays and solve these to find the ratio of light to medium nuclei in the cosmic rays as well as the gamma-ray distribution in our Galaxy. From a comparison of our calculated quantities with observational data we determine the values of various parameters appearing in the model. We find that best agreement between theory and observations is obtained if the cosmic-ray confinement region consists of a narrow disk of total height 160 pc and radius 16 kpc, where the cosmic-ray sources are located, and an extensive halo of height 20 kpc. The diffusion coefficient near the Sun must be between 10²⁶ and 10²⁷ cm² s^–1 while it equals 10²⁸ to 10²⁹ cm² s^–1 in the halo. Finally, we find that the diffusion coefficient in the Galaxy must depend on the gas density as a power law with an index of the order of –1.  相似文献   

Kaimal's isopleths from a closure model     

Osvaldo L. L. Moraes  Joao Goedert 《Boundary-Layer Meteorology》1988,45(1-2):83-92

Kaimal's isopleths for the spectra of the Kansas experiment are derived from a closure model built after Claussen's mechanisms for the spectral transfer of kinetic energy in a steady-state and horizontally homogeneous flow. The connection of the predicted three-dimensional spectrum with the measured one-dimensional one is accomplished via the additional assumption that turbulence in the Kansas experiment was basically isotropic.Partially financed by CAPES, FINEP and CNPq.On leave from Faculdade de Engenharia de Joinville, SC, Brazil.  相似文献   

The infrared emission of quasars     

Carvalho  Joel C. 《Astrophysics and Space Science》1985,111(1):97-102

A model of two compact components (one contributes at radio and submillimeter wavelength and the other is very small and emits at the infrared region) is proposed to interpret the spectrum of quasi-stellar objects at radio and infrared wavelengths. The physical parameters are estimated from the observed data of 3C 273 for our model and for the model which is derived by assuming the infrared emission as an extrapolation of the synchrotron radio-source. It was proved that our model can explain the observational spectra, while the other model has some difficulties to interpret them completely.This work was partially supported by the Brasilian research agency CNPq  相似文献   

An armadillo-like sphagesaurid crocodyliform from the Late Cretaceous of Brazil     

Thiago S. Marinho  Ismar S. Carvalho 《Journal of South American Earth Sciences》2009,27(1):36-41

The Sphagesauridae is a family of Crocodyliformes exclusively known for the Brazilian Late Cretaceous Bauru Basin. This lineage reveals how diverse was the morphology and ecology of terrestrial Crocodyliformes during the Late Cretaceous of Gondwana. Here is described Armadillosuchus arrudai gen. et sp. nov., a sphagesaurid that presents some mammal-like morphological features, such as propalinal and alternate unilateral jaw occlusion pattern and heavy body armor, composed of a rigid shield and mobile-banded section as in extant armadillos (Xenarthra, Dasypodidae). These unusual morphological features contrast to the double row of osteoderms observed on the closest relatives of A. arrudai. As its mammal analogs, A. arrudai presents some evidence of fossoriality and an exclusive terrestrial life style in contrast to the extant alligatorids and crocodylids.  相似文献   

Paleoenvironmental reconstruction of a Late Quaternary lagoon system in southern Brazil (Jaguaruna region,Santa Catarina state) based on multi‐proxy analysis     

Paula Garcia Carvalho do Amaral  Paulo César Fonseca Giannini  Florence Sylvestre  Luiz Carlos Ruiz Pessenda 《第四纪科学杂志》2012,27(2):181-191

This paper provides a paleoenvironmental reconstruction of a Late Quaternary lagoon system in the Jaguaruna region of Santa Catarina state, southern Brazil. Integrated results of bulk sedimentary organic matter characterization (δ¹³C, δ¹⁵N and C/N), microfossil (pollen and diatom) and grain‐size analysis from three shallow cores (～2.5 m depth) allowed us to propose an evolving paleogeographic scenario in this coastal region for the last ca. 5500 cal a BP. The lagoonal system in this area was more extensive during the mid‐Holocene than today, with a gradual and continuous lagoon–sea disconnection until the present. We add to the debate regarding relative sea‐level (RSL) variations for the Brazilian coast during the Holocene and discuss the importance of sedimentary dynamics for interpreting changes in coastal ecosystems. The multi‐proxy analysis suggests that changes in coastal ecosystems could be directly related to local sedimentary processes, which are not necessarily linked to RSL fluctuations and/or to climatic variations. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Dynamic displacement and stress solutions for viscoelastic half‐spaces subjected to harmonic concentrated loads using the Radon and Fourier transforms     

Euclides Mesquita  Marco Adolph  Edson Rodrigues Carvalho  Edivaldo Romanini 《国际地质力学数值与分析法杂志》2009,33(18):1933-1952

In this article a numerical solution for a three‐dimensional isotropic, viscoelastic half‐space subjected to concentrated surface stress loadings is synthesized with the aid of the Radon and Fourier integral transforms. Dynamic displacement and stress fields are computed for points at the surface and inside the domain. The analysis is performed in the frequency domain. Viscoelastic effects are incorporated by means of the elastic–viscoelastic correspondence principle. The equations of motion are solved in the Radon–Fourier transformed domain. Inverse transformations to the physical domain are accomplished numerically. The scheme used to perform the numerical inverse transformations is addressed. The solution is validated by comparison with results available in the literature. A set of original dynamic displacement and stress solutions for points within the half‐space is presented. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Distribution patterns of macrobenthic species in relation to organic enrichment within aquaculture earthen ponds   总被引：1，自引：0，他引：1  

Carvalho S  Barata M  Pereira F  Gaspar MB  Cancela da Fonseca L  Pousão-Ferreira P 《Marine pollution bulletin》2006,52(12):1573-1584

The relationship between organic enrichment and macrobenthic colonization patterns was investigated during an 8-month period in Diplodus sargus (white seabream) production ponds. A stratified sampling design was applied and each pond was divided into three zones: water entrance (WE); central (C); and automatic feeder zones (AF). Generally, the number of species and Shannon–Wiener diversity increased from the WE to the AF zone. Abundance did not present a clear trend. The recently developed marine biotic index (AMBI) was applied and showed to be sufficiently robust to discriminate, within a relatively small area, differences in macrobenthic communities due to organic enrichment. Nevertheless, caution is advised when applying this index or others based on ecological group’s assignment, as the classification of a certain area may differ when allocating a certain species to an unsuitable group. This is particularly evident when common species are involved.  相似文献   

Monte Carlo simulations of radio pulses in atmospheric showers using ZHAireS     

Jaime Alvarez-Muñiz  Washington R. Carvalho Jr.Enrique Zas 《Astroparticle Physics》2012,35(6):325-341

We present predictions for the radio pulses emitted by extensive air showers using ZHAireS, an AIRES-based Monte Carlo code that takes into account the full complexity of ultra-high energy cosmic-ray induced shower development in the atmosphere, and allows the calculation of the electric field in both the time and frequency domains. We do not presuppose any emission mechanism and our results are compatible with a superposition of geomagnetic and charge excess radio emission effects. We investigate the polarization of the electric field as well as the effects of the refractive index n and shower geometry on the radio pulses. We show that geometry, coupled to the relativistic effects that appear when using a realistic refractive index n > 1, play a prominent role on the radio emission of air showers.  相似文献