Solid phases controlling the mobility of potentially toxic elements and the generation of acid drainage in abandoned mine gold wastes from San Antonio–El Triunfo mining district,Baja California Sur,México     

Ernesto Hernández-Mendiola  Francisco Martín Romero  Margarita Gutiérrez-Ruiz  Carlos Alberto Magdaleno Rico 《Environmental Earth Sciences》2016,75(11):969

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Rapid bottom-water circulation changes during the last glacial cycle in the coastal low-latitude NE Atlantic     

David Gallego-Torres  Oscar E. Romero  Francisca Martínez-Ruiz  Jung-Hyun Kim  Barbara Donner  Miguel Ortega-Huertas 《Quaternary Research》2014

Previous paleoceanographic studies along the NW African margin focused on the dynamics of surface and intermediate waters, whereas little attention has been devoted to deep-water masses. Currently, these deep waters consist mainly of North Atlantic Deep Waters as part of the Atlantic Meridional Overturning Circulation (AMOC). However, this configuration was altered during periods of AMOC collapse. We present a high-resolution reconstruction of bottom-water ventilation and current evolution off Mauritania from the last glacial maximum into the early Holocene. Applying redox proxies (Mo, U and Mn) measured on sediments from off Mauritania, we describe changes in deep-water oxygenation and we infer the evolution of deep-water conditions during millennial-scale climate/oceanographic events in the area. The second half of Heinrich Event 1 and the Younger Dryas were recognized as periods of reduced ventilation, coinciding with events of AMOC reduction. We propose that these weakening circulation events induced deficient deep-water oxygenation in the Mauritanian upwelling region, which together with increased productivity promoted reducing conditions and enhanced organic-matter preservation. This is the first time the effect of AMOC collapse in the area is described at high resolution, broadening the knowledge on basin-wide oceanographic changes associated with rapid climate variability during the last deglaciation.  相似文献   

Metal accumulation by plant species growing on a mine contaminated site in Mexico     

Ofelia Morton-Bermea  Juan Miguel Gómez-Bernal  María Aurora Armienta  Rufino Lozano  Elizabeth Hernández-Álvarez  Francisco Romero  Javier Castro-Larragoitia 《Environmental Earth Sciences》2014,71(12):5207-5213

The present work aims to assess the efficiency of heavy metal accumulation of native species growing in contaminated soils in the mining district of Taxco, Mexico. Soil and tailing sampling was conducted in three study sites: La Concha, El Fraile, and a control site. The study localities present diverse metal concentrations with significant differences in their proportion in the geochemical fractions. Results show that species Cupressus lindleyi and Juniperus deppeana accumulate Zn and Mn in anomalous concentrations at La Concha, where Zn is present in soluble fractions. Manganese, despite not being present mostly in the soluble fraction in soils and tailings, seems to have been increased in the soluble fraction after the plant growth. In contrast, samples of the same species taken at El Fraile and in the control site, where Zn and Mn are mainly contained in the residual fraction, do not show an anomalous enrichment. Other analyzed species growing under the same contamination conditions in La Concha (Jacaranda mimosifolia and Psidium guajava) do not show anomalous concentrations. These facts confirm the Zn and Mn accumulation capacity of C. lindleyi and Ju. deppeana, which depends on their accumulation ability and on the concentration of these elements in the soluble fraction.  相似文献   

The MultiDark Database: Release of the Bolshoi and MultiDark cosmological simulations     

K. Riebe  A. M. Partl  H. Enke  J. Forero‐Romero  S. Gottlber  A. Klypin  G. Lemson  F. Prada  J. R. Primack  M. Steinmetz  V. Turchaninov 《Astronomische Nachrichten》2013,334(7):691-708

We present the online MultiDark Database – a Virtual Observatory‐oriented, relational database for hosting various cos‐mological simulations. The data is accessible via an SQL (Structured Query Language) query interface, which also allows users to directly pose scientific questions, as shown in a number of examples in this paper. Further examples for the usage of the database are given in its extensive online documentation. The database is based on the same technology as the Millennium Database, a fact that will greatly facilitate the usage of both suites of cosmological simulations. The first release of the MultiDark Database hosts two 8.6 billion particle cosmological N‐body simulations: the Bolshoi (250 h^–1 Mpc simulation box, 1 h^–1 kpc resolution) and MultiDark Run1 simulation (MDR1, or BigBolshoi, 1000 h^–1 Mpc simulation box, 7 h^–1 kpc resolution). The extraction methods for halos/subhalos from the raw simulation data, and how this data is structured in the database are explained in this paper. With the first data release, users get full access to halo/subhalo catalogs, various profiles of the halos at redshifts z = 0–15, and raw dark matter data for one time‐step of the Bolshoi and four time‐steps of the MultiDark simulation. Later releases will also include galaxy mock catalogs and additional merger trees for both simulations as well as new large volume simulations with high resolution. This project is further proof of the viability to store and present complex data using relational database technology. We encourage other simulators to publish their results in a similar manner. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Acid drainage at the inactive Santa Lucia mine,western Cuba: Natural attenuation of arsenic,barium and lead,and geochemical behavior of rare earth elements     

Francisco Martín Romero  Rosa María Prol-Ledesma  Carles Canet  Laura Núñez Alvares  Ramón Pérez-Vázquez 《Applied Geochemistry》2010

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On the time variability of γ‐ray sources: a numerical analysis of variability indices     

D.F. Torres  M.E. Pessah  G.E. Romero 《Astronomische Nachrichten》2001,322(4):223-227

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