Mineralogical characterization of some basaltic asteroids in the neighborhood of (4) Vesta: first results     

René Duffard  Daniela Lazzaro  Maria Cristina De Sanctis  Jorge M Carvano 《Icarus》2004,171(1):120-132

We present reflectance spectra of 19 V-type asteroids obtained at the 3.6 m Telescopio Nazionale Galileo covering 0.8 to 2.5 μm. For 8 of these asteroids we obtained also visible spectra in the same observational run. The range from 0.8 to 2.5 μm, encompassing the 1 and 2 μm pyroxene features, allows a precise mineralogical characterization of these asteroids. The obtained data suggests the possible coexistence of distinct mineralogical groups among the V-type asteroids, either probing different layers of (4) Vesta or coming from different bodies. No clear correlation was found between mineralogies and the objects being, or not, member of the Vesta dynamical family.  相似文献   

First investigations on the quaternary system Na2O-K2O-CaO-SiO2: synthesis and crystal structure of the mixed alkali calcium silicate K1.08Na0.92Ca6Si4O15     

Kahlenberg  Volker  Mayerl  Michael Jean-Philippe  Schmidmair  Daniela  Krüger  Hannes  Tribus  Martina 《Mineralogy and Petrology》2018,112(2):219-228

Mineralogy and Petrology - In the course of an exploratory study on the quaternary system Na2O-K2O-CaO-SiO2 single crystals of the first anhydrous sodium potassium calcium silicate have been...  相似文献   

Heat wave risk assessment and mapping in urban areas: case study for a midsized Central European city,Novi Sad (Serbia)   总被引：1，自引：0，他引：1  

Stevan Savić  Vladimir Marković  Ivan Šećerov  Dragoslav Pavić  Daniela Arsenović  Dragan Milošević  Dragan Dolinaj  Imre Nagy  Milana Pantelić 《Natural Hazards》2018,91(3):891-911

Risk assessment and mapping methodologies for heat waves as frequently occurring hazards in central and southeastern Europe were applied in this study, and the impact of heat waves on the mortality of urban populations was determined as part of the assessment. The methodology for conducting the heat wave risk assessment is based on European Commission’s Guidelines for Risk Assessment and Mapping. The Novi Sad (Serbia) urban area was studied during summer 2015, which was one of the hottest summers in the last few decades. In situ air temperature measurements from urban stations and mortality of urban populations were used. Nocturnal urban heat island (UHI) intensity values between the various built-up zones and natural surrounding areas were used for the hazard level calculation. Temperature data from 9 p.m. to 5 a.m. were used because during the night, the UHI intensity reached its maximum values. The average daily number of deaths by LCZs was used to define the impact level of the vulnerability index. Calculations for both hazard levels were completed during two intensive heat waves (in July and August 2015) when it was expected that there may be a high level of risk. The results and maps show that the urban area is complex, and the heat wave risk on the population is not uniform. The most densely built-up areas (LCZs 2, 5 and 6) have very high or high risk values that are influenced by a higher rate of mortality. The obtained results and maps can be used by local authorities to prevent and mitigate climate-related hazards, for medical institutions as well as urban planners and for ancillary local, regional or national services. According to these results, the local authorities could define hot spots where they can place medical and rescue teams and install points with water supplies, etc.  相似文献   

Landslide susceptibility modeling assisted by Persistent Scatterers Interferometry (PSI): an example from the northwestern coast of Malta     

Piacentini  Daniela  Devoto  Stefano  Mantovani  Matteo  Pasuto  Alessandro  Prampolini  Mariacristina  Soldati  Mauro 《Natural Hazards》2015,78(1):681-697

Natural Hazards - Persistent Scatterers Interferometry (PSI) techniques are widely employed in geosciences to detect and monitor landslides with high accuracy over large areas, but they also suffer...  相似文献   

Vyacheslav G. Rumynin: Subsurface Solute Transport Models and Case Histories, with Application to Radionuclide Migration     

Daniela Blessent 《Mathematical Geosciences》2013,45(6):773-775

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Solitons and other solutions to the quantum Zakharov-Kuznetsov equation     

Ghodrat Ebadi  Aida Mojaver  Daniela Milovic  Stephen Johnson  Anjan Biswas 《Astrophysics and Space Science》2012,341(2):507-513

In this paper, we present G′/G-expansion method, exp-function method, modified F-expansion method as well as the traveling wave hypothesis for finding the exact traveling wave solutions of the quantum Zakharov-Kuznetsov equation which arises in quantum magneto-plasmas. By these methods, rich families of exact solutions have been obtained, including soliton solutions. This work continues to reinforce the idea that the proposed methods, with the help of symbolic computation, provide a powerful mathematical tool for solving nonlinear partial differential equations.  相似文献   

Natural background levels for some ions in groundwater of the Campania region (southern Italy)     

Daniela Ducci  Mariangela Sellerino 《Environmental Earth Sciences》2012,67(3):683-693

The aim of the study was the determination of the natural background levels (NBLs) for the ions Na⁺, Cl^?, SO₄ ^2?, As³⁺, F^?, Fe²⁺, and Mn²⁺, in some groundwater bodies of the Campania region (southern Italy). The ??Protocol to evaluate the natural background concentrations?? proposed in 2009 by ISPRA (Italian Institute for Environmental Protection and Research) has been applied to the chemical data set of groundwater of the examined groundwater bodies. These analyses have also been examined following the guidelines of the BRIDGE project (Background cRiteria for the IDentification of Groundwater thrEshold). These approaches to evaluate the Threshold Values (TVs) and the NBLs, based on probability distribution functions, have been applied in many countries by various authors during the last 5?years. Changes applied to ISPRA Protocol in this study concern mainly the preselection criteria, in particular threshold values of specific ions, deriving from the aquifers geochemical features. The preselection criteria of the ISPRA Protocol have been merged with those of the BRIDGE Project in order to define a procedure suitable for the definition of the NBLs in the examined aquifers. The NBL of fluoride for the ??Phlegrean Fields?? and the ??eastern Plain of Naples?? groundwater bodies shows values deeply exceeding the reference value (REF) of 1,500???g/L, ranging between 3,600 and 15,000???g/L. The cause of this very high fluoride content is in the natural features of the aquifers constituted by volcanic and pyroclastic rocks. The volcanic origin of the aquifers is also the reason for the high arsenic content in ??Phlegrean Fields?? groundwater. Here the NBL calculated was about 47???g/L against the drinking water standard value of 10???g/L. The widespread high content of manganese and iron for the groundwater body of the ??eastern Plain of Naples?? is due to the reducing conditions related to the extensive marshlands present in the past. The very high NBL of all the examined ions for the groundwater body of ??Ischia Island?? depends on the existence of a geothermal system.  相似文献   

Leucogranite intruding the South Tibetan Detachment in western Nepal: implications for exhumation models in the Himalayas   总被引：1，自引：0，他引：1  

Rodolfo Carosi  Chiara Montomoli  Daniela Rubatto  Dario Visonà 《地学学报》2013,25(6):478-489

The most popular models regarding the exhumation of the Greater Himalayan Sequence (GHS), such as extrusion, channel flow, critical taper and wedge extrusion, require prolonged activity of the two bounding shear zones and faults, the Main Central Thrust (MCT) and the South Tibetan Detachment (STD). We present the crystallization age of an undeformed leucogranite that intrudes both the GHS and the Tethyan Himalaya Sequence (THS). Zircon and monazite U‐Pb ages in the leucogranite give ages between 23 and 25 Ma constraining, at that time, the end of shearing along the STD. Our results limit the contemporaneous activity of the MCT and STD to a short period of time (~1–2 Ma) and thus argue against exhumation models requiring prolonged contemporaneous activity of the MCT and STD.  相似文献   

Les filons sédimentaires jurassiques de Longobucco-Caloveto (Calabre,Italie); application à l’étude des paléostructures d’une marge téthysienne     

Jean-Pierre Bouillin  Daniela Bellomo 《Geodinamica Acta》2013,26(2):111-120

Résumé

La région de Longobucco-Caloveto, dans le Nord du massif de la Sila, en Calabre, montre de très nombreux filons sédimentaires jurassiques qui traversent des schistes cambro-ordovicien ou des granites hercyniens. Ces filons se répartissent en deux groupes. Les plus anciens, d’âge carixien, sont associés à des failles normales qui ont permis la formation d’un demi-graben rempli par des sédiments du Domérien. Les plus récents, d’âge compris entre le Lias supérieur et le Malm, marquent la fracturation de hauts-fonds qui se sont effondrés au Dogger. Ces filons enregistrent ainsi la formation du segment de la marge de la Téthys auquel correspondent les séries de Longobucco-Caloveto. L’étude des relations entre les filons sédimentaires et la fracturation permet de montrer, dans une région pourtant fortement tectonisée au Tertiaire, que différentes failles sont d’âge jurassique : certaines d’entre-elles sont recoupées par des filons et donc antérieures à ceux-ci; d’autres systèmes de filons sont parallèles à des systèmes de failles et donc postérieurs à ces derniers ou contemporains. Us filons sédimentaires apparaissent ainsi comme un moyen intéressant, bien qu’encore peu utilisé, de caractén-sation des dispositifs paléotectoniques.  相似文献   

Spectral and petrologic analyses of basaltic sands in Ka'u Desert (Hawaii) – implications for the dark dunes on Mars     

Daniela Tirsch  Robert Anthony Craddock  Thomas Platz  Alessandro Maturilli  Jörn Helbert  Ralf Jaumann 《地球表面变化过程与地形》2012,37(4):434-448

Dark aeolian deposits on Mars are thought to consist of volcanic materials due to their mineral assemblages, which are common to basalts. However, the sediment source is still debated. Basaltic dunes on Earth are promising analogs for providing further insights into the assumed basaltic sand dunes on Mars. In our study we characterize basaltic dunes from the Ka'u Desert in Hawaii using optical microscopes, electron microprobe, and spectral analyses. We compare the spectra of terrestrial and Martian dune sands to determine possible origins of the Martian dark sediments. Our results show that the terrestrial sands consist primarily of medium to coarse sand‐sized volcanic glass and rock fragments as well as olivine, pyroxene, and plagioclase minerals. Grain shapes range from angular to subrounded. The sample composition indicates that the material was derived from phreatomagmatic eruptions partially with additional proportions of rock fragments from local lava flows. Grain shape and size indicate the materials were transported by aeolian processes rather than by fluvial processes. Spectral analyses reveal an initial hydration of all terrestrial samples. A spectral mineralogical correlation between the terrestrial and Martian aeolian sands shows a similarity consistent with an origin from volcanic ash and lava. We suggest that the Martian deposits may contain similar abundances of volcanic glass, which has not yet been distinguished in Martian spectral data. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献