Antonio Marussi 《Journal of Geodesy》1949,23(4):411-439

Résumé Après avoir introduit un système général de coordonnées dans l’espace (latitude, longitude et cote dynamique) défini à l’aide d’éléments intrinsèques pouvant être déduits de mesures locales, on est amené à considérer le système de base local de vecteurs, et le système réciproque; et par suite les opérations de transformation covariante et contravariante. On introduit de même le tenseur métrique et, après avoir défini l’opération de dérivation covariante et les coefficients de Christoffel de deuxième espèce, on considère quelques autres tenseurs du premier et du deuxième ordre d’importance capitale dans certaines questions de mécanique et de géométrie. Les procédés de calcul différentiel absolu permettent de trouver dans leur forme la plus générale, les conditions d’intégrabilité auxquelles les mesures locales doivent satisfaire; ils permettent aussi le transport des propriétés mécaniques et géométriques du champ potentiel, d’un point à l’autre de l’espace. La question de l’intégration finie des surfaces équipotentielles est abordée à la fin de l’article, ainsi que le problème qui consiste à trouver, par des mesures locales, l’écart entre ces surfaces et celles de rotation.  相似文献   

Il primo problema fondamentale della Geodesia ampliato nel campo di Somigliana     

Prof. Antonio Marussi 《Pure and Applied Geophysics》1950,18(1):55-63

Sommario Dopo aver richiamato l'ampliamento ad un campo potenziale spaziale delle formule diLegendre che risolvono il primo problema fondamentale della Geodesia, l'A. applica tali formule al caso del campo diSomigliana, che ammette l'ellissoide come una delle superfici equipotenziali della famiglia; tale applicazione rappresenta la più naturale estensione ad un campo tridimensionale delle classiche formule ellissoidiche superficiali, e si accorda con l'adozione internazionale del campo diSomigliana per tutte le speculazioni della Geodesia dinamica.

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Summary After having recalled the extension to a spatial potential field ofLegender's formulae solving the first fundamental problem in Geodesy, the author applies such formulae toSomigliana's field, which admits the ellipsoid as one of the equipotential surfaces of the family. Such application represents the most natural extension to a three-dimensional field of the classical ellipsoidal surface formulae, and agrees with the international adoption ofSomigliana's field in dynamic Geodesy.

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Metal distributions and their fluxes at the coastal boundary of a semi-enclosed ria     

Antonio Cobelo-García  Ricardo Prego  Maite DeCastro 《Marine Chemistry》2005,97(3-4):277-292

Water column samples have been collected in the outer channel of the Ferrol Ria (NW Spain) during four occasions over a tidal cycle. The objective was to study the exchange of dissolved and particulate Cd, Cu, Pb and Zn and particulate Al, Fe and Si between the ria and the adjacent coastal waters. This study provides the first extensive dataset on dissolved and particulate metal concentrations in the water column of a Galician ria. Typical concentrations of dissolved Cd (96 ± 31 pM), Cu (8 ± 4 nM), Pb (270 ± 170 pM) and Zn (21 ± 10 nM) were similar than in other European Atlantic shelf and coastal waters. The fraction of metals in the particulate phase followed the trend: Pb > Cu Zn > Cd. The outgoing water from the ria was enriched in dissolved and particulate Cu, Pb and Zn compared with incoming waters, whereas Cd concentrations were similar for both waters. The suspended particulate matter was composed of a mixture of marine and continental material. The latter end-member was found to arise from the metal-rich ria bed sediments, which is diluted by the dominant metal-poor marine end-member. The net output flux of Cu from the channel is balanced by the freshwater inputs to the ria, and the net Zn flux gave a positive output to coastal waters. For Pb, the net flux to the coastal waters is less than that input from the rivers, as a result of its particle reactivity and deposition in sediments. On the contrary, a net input flux of dissolved Cd from coastal waters was observed, highlighting the oceanic source of this metal in the Galician rias. Results from the budget calculations are in agreement with the differential geochemical behavior of these elements in coastal waters.  相似文献   

Variations of Hydrochemical Features in the Coastal Waters of Monte Conero: 1982–1990     

Mauro Marini  Paola Fornasiero  Antonio Artegiani 《Marine Ecology》2002,23(S1):258-271

Abstract. This paper briefly summarises research carried out in 1982–1990 in the coastal area off Monte Conero, SW northern Adriatic Sea. Oceanographic data on temperature, salinity, oxygen saturation, nutrients (nitrates, silicates and orthophosphates), and chlorophylls were collected to characterise this coastal ecosystem in view of the setting up of the "Costa del Monte Conero" protected marine area.
Towards the coast the physical and chemical parameters exhibited a seasonal periodicity.
Temperature showed a clear annual periodicity with a certain interannual variability; this also holds true for oxygen saturation, with peaks in March and minima in September, though without hypoxic events.
Nutrient concentrations peaked at the surface layer at the coastal station from December to March (nitrates: 35–50 μmol 1⁻¹; silicates: 22–70 μmol 1⁻¹; orthophosphates: 0.37–0.54 μmol 1⁻¹) and minima in summer (Jul-Aug) on surface and bottom (0–12μmol 1⁻¹, 0–18.5 μmol 1⁻¹, and 0–0.15 μmol 1⁻¹, respectively). From 1988 to 1990 nutrient peaks were lower and coastal salinity exceed 33, with nitrates below 16 μmol 1⁻¹, silicates below 8 μmol 1⁻¹, and orthophosphates less than 0.2 μmol 1⁻¹.
In the coastal area of Senigallia, 40 km to the north, where the influence of the coastal current that carries the river inflows to the south is stronger, the seasonal cycle was similar, albeit with higher values for nutrients and chlorophylls.  相似文献   

The PAH composition of surface sediments from Stagnone coastal lagoon, Marsala (Italy)   总被引：2，自引：0，他引：2  

Loredana Culotta  Concetta De Stefano  Antonio Gianguzza  Maria Rosaria Mannino  Santino Orecchio   《Marine Chemistry》2006,99(1-4):117

This paper examines the presence, distribution, nature and sources of 22 Aromatic Hydrocarbons (PAHs), which are important environmentally and toxicologically, in sediments from the Stagnone coastal lagoon at Marsala (Italy). Analysis was performed by gas chromatography/mass spectrometry (GC/MS) with selected ion monitoring (SIM). The total concentration of polycyclic aromatic hydrocarbons ranged from 72 to 18381 μg/kg of dry matrix. The relative standard deviation (RSD) of the replicates on the concentrations of individual compounds ranged from 5% to 20%. The accuracy of method was estimated by analyzing “blank” samples added of known quantities of analytes and the recover percentage was 88 ± 9%. The detection limit (LOD) of analytical procedure was less than 0.2 μg/kg d.w. for all analytes. The quantification limit (LOQ) of analytical procedure was less than 0.7 μg/kg d.w.The resulting distributions and weight ratios of specific compounds are discussed in terms of sampling location and origin of organic matter. A comparison with other studies of total PAHs suggests that the levels are within the concentration ranges already reported by other authors. From an eco-toxicological point of view, total PAH concentrations at seven out of the eight sites studied represent a relatively clean environment when compared to other sites.Organic matter content and PAH concentrations were found to be correlated and the compounds present in Stagnone sediments were shown to be mainly of pyrolitic origin, while a negligible quantity of PAHs may derive from biogenic sources since all the sediments contain perylene traces. There is no evidence of coal-tar contamination.Cluster analysis was carried out in order to discriminate between different PAH origins.  相似文献   

Taxonomic versus trophic structure of mesozooplankton: a seasonal study of species succession and stable carbon and nitrogen isotopes in a coastal upwelling ecosystem   总被引：2，自引：0，他引：2  

Bode  Antonio; Alvarez-Ossorio  Maria Teresa 《ICES Journal of Marine Science》2004,61(4):563-571

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Settlement and primary succession in a shallow submarine cave: spatial and temporal benthic assemblage distinctness   总被引：1，自引：0，他引：1  

Francesco Denitto  Antonio Terlizzi  & Genuario Belmonte 《Marine Ecology》2007,28(S1):35-46

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Sources and transfer of organic matter in food webs of a Mediterranean coastal environment: Evidence for spatial variability   总被引：4，自引：0，他引：4  

Salvatrice Vizzini  Antonio Mazzola 《Estuarine, Coastal and Shelf Science》2006,66(3-4):459-467

The spatial variability in the food web structure of a Mediterranean semi-enclosed coastal environment (Stagnone di Marsala, Italy) was investigated using stable carbon and nitrogen isotopes. Organic matter sources and consumers were sampled in two locations with different environmental features (e.g. hydrodynamic regime, open-sea influence, vegetal coverage). Overall more ¹³C-enriched and ¹⁵N-depleted values were found in the central location than in the southern for organic matter sources and consumers. Pelagic consumers (zooplankton and juveniles of transient fish) showed slight spatial differences and in both locations seemed to depend on phytoplankton as the ultimate energy source. In contrast, benthic consumers (epifauna and resident fish) exhibited remarkable differences between locations. Spatial differences in organic matter sources were smaller than in benthic consumers and thus consumers presumably exploited different ultimate organic matter sources in the two locations. Sedimentary organic matter and epiphytes appeared to be the main primary producers transferred within the food web in both locations, and seagrasses seemed to play a non-negligible trophic role in the central location. The results of this paper corroborate the finding food webs are characterised by high spatial variability even on a small spatial scale and environmental heterogeneity more than primary production that seems to influence the trophic role of autotrophs.  相似文献   

Modelling of natural and synthetic polyelectrolyte interactions in natural waters by using SIT, Pitzer and Ion Pairing approaches     

Francesco Crea  Alba Giacalone  Antonio Gianguzza  Daniela Piazzese  Silvio Sammartano   《Marine Chemistry》2006,99(1-4):93

In this paper SIT and Pitzer models are used for the first time to describe the interactions of natural and synthetic polyelectrolytes in natural waters. Measurements were made potentiometrically at 25 °C in single electrolyte media, such as Et₄NI and NaCl (for fulvic acid 0.1 < I /mol L^− 1 < 0.75), and in a multi-component medium simulating the composition of natural waters at a wide range of salinities (for fulvic and alginic acids: 5 < S < 45) with particular reference to sea water [Synthetic Sea Water for Equilibrium studies, SSWE]. In order to simplify calculations, SSWE was considered to be a “single salt” BA, with cation B and anion A representing all the major cations (Na⁺, K⁺, Mg²⁺, Ca²⁺) and anions (Cl⁻, SO₄²⁻) in natural sea water, respectively. The ion pair formation model was also applied to fulvate and alginate in artificial sea water by examining the interaction of polyanions with the single sea water cation. Results were compared with those obtained from previous speciation studies of synthetic polyelectrolytes (polyacrylic and polymethacrylic acids of different molecular weights). Results indicate that the SIT, Pitzer and Ion Pairing formation models used in studies of low molecular weight electrolytes may also be applied to polyelctrolytes with a few simple adjustments.  相似文献   

Land inputs,behaviour and contamination levels of copper in a ria estuary (NW Spain)     

Cobelo-García A  Prego R 《Marine environmental research》2003,56(3):403-422

Copper concentrations were measured in the sediments and dissolved phase of the water column in the Lérez Estuary (Pontevedra Ria, Galicia), NW Spain, and in the freshwater-sewage inputs to the estuary. Dissolved copper fluxes in the estuary were quantified. Results show that the freshwater end-member in the Lérez Estuary has minimal copper contamination ([Cu](Dissolved)=7+/-4 nM, Sediment Enrichment Factor=1) and the source of dissolved copper inputs is localized in the saline end-member ([Cu](Dissolved)=20-55 nM, Sediment Enrichment Factor=6-7). A non-conservative behaviour of dissolved copper showing a net addition during estuarine mixing was observed. The budgetary calculations and the copper sediment distribution suggest that the major copper input to the estuary-ria system is located at the Marín-Placeres transect, playing an important role in the net addition of copper within the estuarine mixing. The importance of upwelling in the renewal of the Galician coastal waters and dilution of continental inputs is discussed.  相似文献