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51.
Carmen Morales José F. Gómez Joaquín Trapero Stuart Bowyer Jerry Edelstein Eric Korpela 《Astrophysics and Space Science》1998,263(1-4):393-396
EURD (Espectrógrafo Ultravioleta extremo de Radiación Difusa), one of the instruments onboard the Spanish satellite MINISAT-01,
is a spectrograph specially designed to detect diffuse radiation, covering the wavelength range of 350-1100 Å, with a spectral
resolution of 6-8 Å. Its main scientific objectives are the detection of the emission line spectrum from the hot phase of
the interstellar medium and the spectrum of the upper atmospheric airglow. In order to reduce geocoronal noise, EURD always
observes in the anti-sun direction and only when the satellite is in orbital eclipse. After more than one year of observation
we have obtained the best spectrum of the upper atmospheric nightglow in this wavelength range, the spectrum of 15 OB stars
and the spectrum of the full Moon throughout the year.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
52.
Joaquín A. Cortés 《Mathematical Geosciences》2009,41(7):817-828
The current theoretical development of the analysis of compositional data in the article by Aitchison and Egozcue neglects
the use of Harker’s variation diagrams and other similar plots as “meaningless” or “useless” on compositional data. In this
work, it is shown that variation diagrams essentially are not a correlation tool but a graphical representation of the mass
actions and mass balances principles in the context of a given geological system, and, when they are used correctly, they
provide vital information for the igneous petrologist. The qualitative validity of the “spurious trends” in these diagrams
is also shown, when they are interpreted in their proper geological framework. The example previously used by Rollinson to
test the usefulness of the log-ratio transformation in the Aitchison and Egozcue article is revisited here in order to fully
illustrate the proper use of this tool. 相似文献
53.
Rare earth elements (REE) were analyzed in surface sediments from the Guadiana Estuary (SW Iberian Pyrite Belt). NASC (North American Shale Composite) normalized REE patterns show clearly convex curvatures in middle-REE (MREE) with respect to light- and heavy-REE, indicating acid-mixing processes between fluvial waters affected by acid mine drainage (AMD) and seawater. However, REE distributions in the mouth (closer to the coastal area) show slightly LREE-enriched and flat patterns, indicating saline-mixing processes typical of the coastal zone. NASC-normalized ratios (La/Gd and La/Yb) do not discriminate between both mixing processes in the estuary. Instead, a new parameter (E(MREE)) has been applied to measure the curvature in the MREE segment. The values of E(MREE)>0 are indicative of acid signatures and their spatial distribution reveal the existence of two decantation zones from flocculation processes related to drought periods and flood events. Studying REE fractionation through the E(MREE) may serve as a good proxy for AMD-pollution in estuarine environments in relation to the traditional methods. 相似文献
54.
Enrique Peña González Joaquín Suárez López Jordi Delgado Martín Alfredo Jácome Burgos Jerónimo Puertas Agudo 《Environmental Geology》2006,50(6):823-834
The cutting operations of dimension stone at quarries produce a large amount of fines that, in turn, cause a negative environmental impact over local surface waters. This article presents a detailed analysis of the mobilized contamination associated with runoff waters in a large granite quarry (~200 ha) which is located in Porriño (Galicia, NW Spain), the most important production centre of dimension stone in Spain. There, an intensive monitoring survey was developed in order to characterize the hydrology of the system as well as the release and transport of pollutants. This was accomplished by means of different control sections for the flow and by the collection of 52 random water samples. Automatic samplers were also used to collect 192 water samples associated with runoff generated by significant rain events. For each of the samples collected, a wide battery of analytic determinations was performed, including solid loads, turbidity, organic pollution, nutrient and selected metals. Upon careful examination it has been possible to obtain different parameters related to the contamination control, like the “event mean concentration” (EMC), maximum concentrations and specific sediment loads. Moreover, a comprehensive statistical study including parameter correlation and cumulative probability analyses helped to understand the pollutant mobilization behaviour within the quarry system. It can be concluded that mobilized contamination shows the anomalous presence of some metals, whose concentrations are in excess when compared to the natural rock. This excess metal amount must be attributed to an anthropogenic source associated to mining and cutting operations. 相似文献
55.
José F. Gómez Joaquín Trapero Carmen Morales Verónica Orozco Jerry Edelstein Eric Korpela Michael Lampton 《Astrophysics and Space Science》2001,276(1):233-238
EURD (EspectrógrafoUltravioleta extremo para la Radiación Difusa) is one of thescientific instruments on board MINISAT 01. EURD is a spectrograph withvery high sensitivity and spectral resolution ( 5 Å), designed to obtain extremeultraviolet ( 350-1100 Å) spectra of diffuse radiation.We outline the processing of EURD data, and how we obtain informationfrom these data on the scientific goals of the mission: hot interstellarmedium, neutrino decay line, nightglow emission, and early-type stars. 相似文献