Intra-annual variation and baseline concentrations of dissolved trace metals in the Vigo Ria and adjacent coastal waters (NE Atlantic Coast)     

Juan Santos-Echeandía  Antonio Cobelo-García 《Marine pollution bulletin》2009,58(2):298-58

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Use of Chitosan with Different Deacetylation Degrees for the Adsorption of Food Dyes in a Binary System          下载免费PDF全文

Janaína O. Gonçalves  Diana A. Duarte  Guilherme L. Dotto  Luiz Antonio A. Pinto 《洁净——土壤、空气、水》2014,42(6):767-774

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Representivity of incompletely sampled fall deposits in estimating eruption source parameters: a test using the 12–13 January 2011 lava fountain deposit from Mt. Etna volcano,Italy     

Daniele Andronico  Simona Scollo  Antonio Cristaldi  Maria Deborah Lo Castro 《Bulletin of Volcanology》2014,76(10):1-14

The Southeast Crater (SEC) of Mt. Etna, Italy, is renowned for its high activity, mainly long-lived eruptions consisting of sequences of individual paroxysmal episodes which have produced more than 150 eruptive events since 1998. Each episode typically forms eruption columns followed by tephra fallout over distances of up to about 100 km from the vent. One of the last sequences consisted of 25 lava fountaining events, which took place between January 2011 and April 2012 from a pit-vent on the eastern flank of the SEC and built a new scoria cone renamed New Southeast Crater. The first episode on 12–13 January 2011 produced tephra fallout which was unusually dispersed toward to the South extending out over the Mediterranean Sea. The southerly deposition of tephra permitted an extensive survey at distances between ~1 and ~100 km, providing an excellent characterization of the tephra deposit. Here, we document the stratigraphy of the 12–13 January fallout deposit, draw its dispersal, and reconstruct its isopleth map. These data are then used to estimate the main eruption source parameters. The total erupted mass (TEM) was calculated by using four different methodologies which give a mean value of 1.5?±?0.4?×?10⁸ kg. The mass eruption rate (MER) is 2.5?±?0.7?×?10⁴ kg/s using eruption duration of 100 min. The total grain-size (TGS) distribution, peaked at ?3 phi, ranges between ?5 and 5 phi and has a median value of ?1.4 phi. Further, for the eruption column height, we obtained respective values of 6.8–13.8 km by using the method of Carey and Sparks (1986) and 3.4?±?0.3 km by using the methods of Wilson and Walker (1987), Mastin et al. (2009), and Pistolesi et al. (2011) and considering the mean value of MER from the deposit. We also evaluated the uncertainty and reliability of TEM and TGS for scenarios where the proximal and distal samples are not obtainable. This is achieved by only using a sector spanning the downwind distances between 6 and 23 km. This scenario is typical for Etna when the tephra plume is dispersed eastward, i.e., in the prevailing wind direction. Our results show that, if the analyzed deposit has poorer sample coverage than presented in this study, the TEM (3.4?×?10⁷ kg) is 22 % than the TEM obtained from the whole deposit. The lack of the proximal (<6 km) deposit may cause more significant differences in the TGS estimations.  相似文献   

The state of water resources in major Mediterranean islands     

Francesco Viola  Manuel Sapiano  Michael Schembri  Clive Brincat  Antonio Lopez  Attilio Toscano  Evan Diamadopoulos  Bambos Charalambous  Bruno Molle  Michael Zoumadakis  Antonina Torrens Armengol  Margarita Gallinas Vich  Maria Teresa Noto 《Water Resources》2014,41(6):639-648

This work analyses the state of water resources in six Mediterranean islands: Corsica, Crete, Cyprus, Mallorca, Malta and Sicily. The analysis is focused on the prevailing social, economic and hydroclimatological characteristics of these islands in order to identify the main common features affecting water availability, demand and use. A detailed analysis of the state of water resources in all the considered islands has been carried out. A background of current conditions relating to freshwater availability, quality and use has been established. Different strategies to face water scarcity and enhance water quality in theislands have been assessed in a context of climate change which is a common threat. The identification of similar problems for all the islands highlights the importance of strengthening inter-islands co-operation in the field of sustainable water resources management.  相似文献   

Polarimetry of young stellar objects – III. Circular polarimetry of OMC-1     

Antonio Chrysostomou  T. M. Gledhill  François Ménard  J. H. Hough  Motohide Tamura  Jeremy Bailey 《Monthly notices of the Royal Astronomical Society》2000,312(1):103-115

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Hydrodynamical simulations of the Sunyaev–Zel'dovich effect     

Antonio C. da Silva  Domingos Barbosa  rew R. Liddle  Peter A. Thomas 《Monthly notices of the Royal Astronomical Society》2000,317(1):37-44

With detections of the Sunyaev–Zel'dovich (SZ) effect induced by galaxy clusters becoming routine, it is crucial to establish accurate theoretical predictions. We use a hydrodynamical N -body code to generate simulated maps, of size 1 deg², of the thermal SZ effect. This is done for three different cosmologies: the currently favoured low-density model with a cosmological constant, a critical-density model and a low-density open model. We stack simulation boxes corresponding to different redshifts in order to include contributions to the Compton y -parameter out to the highest necessary redshifts. Our main results are as follows.
(i) The mean y -distortion is around 4×10⁻⁶ for low-density cosmologies, and 1×10⁻⁶ for critical density. These are below current limits, but not by a wide margin in the former case.
(ii) In low-density cosmologies, the mean y -distortion is contributed across a broad range of redshifts, with the bulk coming from z ≲2 and a tail out to z ∼5. For critical-density models, most of the contribution comes from z <1.
(iii) The number of SZ sources above a given y depends strongly on instrument resolution. For a 1-arcmin beam, there are around 0.1 sources per deg² with y >10⁻⁵ in a critical-density Universe, and around 8 such sources per deg² in low-density models. Low-density models with and without a cosmological constant give very similar results.
(iv) We estimate that the Planck satellite will be able to see of order 25 000 SZ sources if the Universe has a low density, or around 10 000 if it has critical density.  相似文献   

Polarization models of young stellar objects – II. Linear and circular polarimetry of R Coronae Australis     

Stuart Clark  Alan McCall  Antonio Chrysostomou  Tim Gledhill  Jeremy Yates  James Hough 《Monthly notices of the Royal Astronomical Society》2000,319(2):337-349

Near-infrared linear imaging polarimetry of the young stellar objects R CrA and T CrA in the J , H and K n bands, and circular imaging polarimetry in the H band, is presented. The data are modelled with the Clark and McCall scattering model. The R CrA and T CrA system is shown to be a particularly complex scattering environment. In the case of R CrA there is evidence that the wavelength dependence of polarization changes across the nebula. MRN dust grain models do not explain this behaviour. Depolarization by line emission is considered as an alternative explanation. The dust grain properties could also be changing across the nebula.
Although surrounded by reflection nebulosity, there is a region of particularly low polarization surrounding R CrA that is best modelled by the canonical bipolar outflow being truncated by an evacuated spherical cavity surrounding the star. The symmetry axis of the nebula appears inclined by 50° to the plane of the sky.
The H -band circular polarimetry of R CrA clearly shows a quadrupolar structure of positive and negative degrees of circular polarization that reach peak magnitudes of ∼5 per cent within our limited map. It is shown that spherical MRN grains are incapable of producing this circular polarization given the observed linear polarization of the R CrA system. Instead, scattering from aligned non-spherical grains is proposed as the operating mechanism.
T CrA is a more archetypical bipolar reflection nebula, and this object is modelled as a canonical parabolic reflection nebula that lies in the plane of the sky. The wavelength independence of linear polarization in the T CrA reflection nebula suggests that the scattering particles are Rayleigh sized. This is modelled with the MRN interstellar grain size distribution.  相似文献   

Multi-frequency electromagnetic method for inductive measurement of ground induced polarization and resistivity     

Carlos Alberto Dias  Hédison Kiuity Sato  Marcos Vitor Barbosa Machado  Olivar Antonio Lima de Lima 《Geophysical Prospecting》2019,67(1):210-225

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A New TanSat XCO_2 Global Product towards Climate Studies     

Dongxu YANG  Yi LIU  Hartmut BOESCH  Lu YAO  Antonio DI NOIA  Zhaonan CAI  Naimeng LU  Daren LYU  Maohua WANG  Jing WANG  Zengshan YIN  Yuquan ZHENG 《大气科学进展》2021,38(1):8-11

The 1st Chinese carbon dioxide(CO2)monitoring satellite mission,TanSat,was launched in 2016.The 1st TanSat global map of CO2 dry-air mixing ratio(XCO2)measurements over land was released as version 1 data product with an accuracy of 2.11 ppmv(parts per million by volume).In this paper,we introduce a new(version 2)TanSat global XCO2 product that is approached by the Institute of Atmospheric Physics Carbon dioxide retrieval Algorithm for Satellite remote sensing(IAPCAS),and the European Space Agency(ESA)Climate Change Initiative plus(CCI+)TanSat XCO2 product by University of Leicester Full Physics(UoL-FP)retrieval algorithm.The correction of the measurement spectrum improves the accuracy(?0.08 ppmv)and precision(1.47 ppmv)of the new retrieval,which provides opportunity for further application in global carbon flux studies in the future.Inter-comparison between the two retrievals indicates a good agreement,with a standard deviation of 1.28 ppmv and a bias of?0.35 ppmv.  相似文献   

Spatial and environmental analysis of an ostracod metacommunity from endorheic lakes     

Andreu Castillo-Escrivà  Luis Valls  Carlos Rochera  Antonio Camacho  Francesc Mesquita-Joanes 《Aquatic Sciences - Research Across Boundaries》2016,78(4):707-716

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