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Maximiliano C.L. Rocca  Michael R. Rampino  Jaime L. Báez Presser 《地学学报》2017,29(4):i-i

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Reply to Comments on “Geophysical evidence for a large impact structure on the Falkland (Malvinas) Plateau”          下载免费PDF全文

Michael R. Rampino  Maximiliano C. L. Rocca  Jaime L. B. Presser 《地学学报》2017,29(6):416-419

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Erratum to: Distribution and thickness of sedimentary facies in the coastal dune, beach and nearshore sedimentary system at Maspalomas, Canary Islands     

Angela Fontán Bouzas  Javier Alcántara-Carrió  Isabel Montoya Montes  Andrés Barranco Ojeda  Silvia Albarracín  Jaime Rey Díaz de Rada  Jorge Rey Salgado 《Geo-Marine Letters》2013,33(2-3):231-231

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Suitability of GNSS for analysis of soil subsidence in Recife in a highly urbanized coastal area     

de Luna  Rejane Maria Rodrigues  dos Anjos Garnés  Silvio Jacks  da Silva Pereira Cabral  Jaime Joaquim  dos Santos  Sylvana Melo 《Natural Hazards》2021,106(3):1821-1837

Natural Hazards - Recife Metropolitan Region, in the northeast of Brazil, is formed by a coastal plain bounded by hills and by the Atlantic Ocean. Recife Metropolitan Region has about 4 million...  相似文献   

Radio planetary nebulae in the Magellanic Clouds     

M. D. Filipovi&#;  M. Cohen  W. A. Reid  J. L. Payne  Q. A. Parker  E. J. Crawford  I. S. Boji&#;i&#;  A. Y. De Horta  A. Hughes  J. Dickel  F. Stootman 《Monthly notices of the Royal Astronomical Society》2009,399(2):769-777

We report the extragalactic radio-continuum detection of 15 planetary nebulae (PNe) in the Magellanic Clouds (MCs) from recent Australia Telescope Compact Array+Parkes mosaic surveys. These detections were supplemented by new and high-resolution radio, optical and infrared observations which helped to resolve the true nature of the objects. Four of the PNe are located in the Small Magellanic Cloud (SMC) and 11 are located in the Large Magellanic Cloud (LMC). Based on Galactic PNe the expected radio flux densities at the distance of the LMC/SMC are up to ∼2.5 and ∼2.0 mJy at 1.4 GHz, respectively. We find that one of our new radio PNe in the SMC has a flux density of 5.1 mJy at 1.4 GHz, several times higher than expected. We suggest that the most luminous radio PN in the SMC (N S68) may represent the upper limit to radio-peak luminosity because it is approximately three times more luminous than NGC 7027, the most luminous known Galactic PN. We note that the optical diameters of these 15 Magellanic Clouds (MCs) PNe vary from very small (∼0.08 pc or 0.32 arcsec; SMP L47) to very large (∼1 pc or 4 arcsec; SMP L83). Their flux densities peak at different frequencies, suggesting that they may be in different stages of evolution. We briefly discuss mechanisms that may explain their unusually high radio-continuum flux densities. We argue that these detections may help solve the 'missing mass problem' in PNe whose central stars were originally  1–8 M_⊙  . We explore the possible link between ionized haloes ejected by the central stars in their late evolution and extended radio emission. Because of their higher than expected flux densities, we tentatively call this PNe (sub)sample –'Super PNe'.  相似文献   

Mesozoic Evaniidae (Insecta: Hymenoptera) in Spanish Amber: Reanalysis of the Phylogeny of the Evanioidea     

Enrique PE?ALVER  Jaime ORTEGA-BLANCO  André NEL  Xavier DELCLòS 《《地质学报》英文版》2010,84(4):809-827

<正>One new genus and five new species of the family Evaniidae are described from the Early Cretaceous (Albian)Spanish amber of Penacerrada-Ⅰ(Province of Burgos),San Just and Arroyo de la Pascueta(both in the Province of Teruel):Cretevania alonsoi sp.nov.,C.montoyai sp.nov.,C.alcalai sp.nov.,C.rubusensis sp.nov.,and Iberoevania roblesi gen.and sp.nov.Taxonomic changes include Cretevania pristina(Zhang and Zhang,2000) comb.nov.,C.exquisita(Zhang,Rasmtsyn,Wang and Zhang,2007)comb.nov.,C.vesca(Zhang,Rasnitsyn,Wang and Zhang,2007)comb.nov.,and C.cyrtocerca(Deans,2004)comb.nov.,as a result of the reinterpretation of the genera Procretevania and Eovernevania.The new well preserved specimens of the genus Cretevania,together with the characters shown by the type specimens of the synonymized genera,give new information about their anatomical characters of taxonomical importance,and the genus Cretevania Rasnitsyn,1975 is re-diagnosed.The holotypes of the Russian species in amber have been revised.A cladistic analysis of fossil and extant groups of the superfamily Evanioidea is included.Cretevania had a wide palaeogeographic distribution,with the highest diversity known from Spain.The 13 known Cretevania species show a high interspecific variation mainly in wing characteristics,and a wide range of body and wing size.  相似文献   

Direct Sequential Co-simulation with Joint Probability Distributions   总被引：1，自引：1，他引：0  

Ana Horta  Amílcar Soares 《Mathematical Geosciences》2010,42(3):269-292

The practice of stochastic simulation for different environmental and earth sciences applications creates new theoretical problems that motivate the improvement of existing algorithms. In this context, we present the implementation of a new version of the direct sequential co-simulation (Co-DSS) algorithm. This new approach, titled Co-DSS with joint probability distributions, intends to solve the problem of mismatch between co-simulation results and experimental data, i.e. when the final biplot of simulated values does not respect the experimental relation known for the original data values. This situation occurs mostly in the beginning of the simulation process. To solve this issue, the new co-simulation algorithm, applied to a pair of covariates Z ₁(x) and Z ₂(x), proposes to resample Z ₂(x) from the joint distribution F(z ₁,z ₂) or, more precisely, from the conditional distribution of Z ₂(x ₀), at a location x ₀, given the previously simulated value z₁^(l)(x₀)z_{1}^{(l)}(x_{0}) (F(Z₂|Z₁=z₁^(l)(x₀)F(Z_{2}|Z_{1}=z_{1}^{(l)}(x_{0}) ). The work developed demonstrates that Co-DSS with joint probability distributions reproduces the experimental bivariate cdf and, consequently, the conditional distributions, even when the correlation coefficient between the covariates is low.  相似文献   

Ground water/surface water interaction in a fractured rock aquifer   总被引：1，自引：0，他引：1  

Oxtobee JP  Novakowski KS 《Ground water》2003,41(5):667-681

In a recent field study of ground water/surface water interaction between a bedrock stream and an underlying fractured rock aquifer, it was determined that the majority of ground water discharge occurred through sparsely located vertical fractures. In this paper, the dominant mechanisms governing ground water/surface water exchange in such an environment are investigated using a numerical model. The study was conducted using several conceptual models based on the field study results. Although the field results provided the motivation for the modeling study, it was not intended to match modeling and field results directly. In addition, the extent of capture zones for discharging or recharging fractures was explored. The results of this study are intended to provide a better understanding of contaminant migration in the vicinity of bedrock streams. Based on the numerical results, the rate of ground water discharge (or recharge) was found to depend on the aperture size of the discharging feature, and on the distribution of hydraulic head with depth within the fracture network. It was determined that the extent of both the capture zone and reverse capture zone for an individual fracture can be extremely large, and will be determined by the height of the stream stage, the fracture apertures of the network, and the hydraulic-head distribution within the network. Because both the stream stage and the hydraulic-head distribution are transient, the size of the capture zone and/or the reverse capture zone for an individual fracture may change significantly over time. As a result, the migration path for contaminants within the fracture network and between the surface and subsurface will also vary significantly with time.  相似文献   

Intrinsic aquifer vulnerability assessment: validation by environmental tracers in San Miguel de Allende, Mexico   总被引：1，自引：0，他引：1  

Jürgen Mahlknecht  Ma. Guadalupe Medina-Mejía  Jaime Gárfias-Solis  Irene Cano-Aguilera 《Environmental Geology》2006,51(3):477-491

Vulnerability maps are important tools for water decision makers and land-use planners for protection of aquifers against contamination. The vulnerability map, according to the parametric method SINTACX for assessing intrinsic aquifer vulnerability, was validated in a case study with chlorofluorocarbon tracer technologies (CFC-11, CFC-12, and CFC-113) of groundwater. The tested area was the 1,295 km² volcano-sedimentary area of San Miguel de Allende (SMA), Mexico. From the results of this area, it appears that the vulnerability map is in parts inconsistent with the underlying groundwater flow system. Thus, the vulnerability map was corrected with tracer information. The validated vulnerability map indicates that the degree of vulnerability varies from low to moderate-high. Low vulnerability values are found in the graben extending from north to south along the SMA fault system and high values in recharge areas southeast and northwest of the study area. The investigation is a demonstration that the scientific reliability of results of the parametric method can be improved by validation with tracer techniques representing the groundwater dynamics. The flexible structure of SINTACX allows revising and adjusting scores and weights of the parameter maps to rebuild a new vulnerability map consistent with the hydrological system.  相似文献   

Upscaling Hydraulic Conductivities in Cross-Bedded Formations     

Xian-Huan Wen  J. Jaime Gómez-Hernández 《Mathematical Geology》1998,30(2):181-211

Modern geostatistical techniques allow the generation of high-resolution heterogeneous models of hydraulic conductivity containing millions to billions of cells. Selective upscaling is a numerical approach for the change of scale of fine-scale hydraulic conductivity models into coarser scale models that are suitable for numerical simulations of groundwater flow and mass transport. Selective upscaling uses an elastic gridding technique to selectively determine the geometry of the coarse grid by an iterative procedure. The geometry of the coarse grid is built so that the variances of flow velocities within the coarse blocks are minimum. Selective upscaling is able to handle complex geological formations and flow patterns, and provides full hydraulic conductivity tensor for each block. Selective upscaling is applied to a cross-bedded formation in which the fine-scale hydraulic conductivities are full tensors with principal directions not parallel to the statistical anisotropy of their spatial distribution. Mass transport results from three coarse-scale models constructed by different upscaling techniques are compared to the fine-scale results for different flow conditions. Selective upscaling provides coarse grids in which mass transport simulation is in good agreement with the fine-scale simulations, and consistently superior to simulations on traditional regular (equal-sized) grids or elastic grids built without accounting for flow velocities.  相似文献