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81.
King Nia Bishop-Williams Katherine E. Beauchamp Sabrina Ford James D. Berrang-Ford Lea Cunsolo Ashlee Team IHACC Research Harper Sherilee L. 《Climatic change》2019,152(3-4):581-596
Climatic Change - Research on climate change media coverage is growing. Few studies, however, have investigated how the media portrays climate change impacts on human health. This review,... 相似文献
82.
A. Gherardi M. Romoli E. Pace M. Pancrazzi G. Rossi D. Paganini M. Focardi 《Astrophysics and Space Science》2009,320(1-3):239-241
The HERSCHEL/SCORE is a suborbital mission which will observe the solar corona in UV and in visible light for measurements of solar corona. The coronagraph for such observation is an Italian instrument and, in particular, the CCD camera detectors are developed at the XUVLab of the Department of Astronomy and Space Science of Florence University. Such detectors communicate with the onboard computer by means the IEEE1355 Spacewire standard interface (developed in our laboratories) and implement a lot of smart and custom procedures for imaging. The main innovation of SCORE coronagraph is the first use in space of a variable retarder plate based on liquid crystals and the optical design capable of simultaneous observation in UV and Visible light. 相似文献
83.
Coordination of boron in nominally boron-free rock forming silicates: Evidence for incorporation of BO3 groups in clinopyroxene 总被引:1,自引:0,他引:1
Ulf Hålenius Henrik Skogby Sabrina Nazzareni Jeppa Resmark 《Geochimica et cosmochimica acta》2010,74(19):5672-1594
To explore mechanisms of B-incorporation in common chain silicates we have investigated synthetic diopside samples produced under boron-saturated conditions by 11B and 29Si magic-angle spinning (MAS) NMR and single-crystal NRA, FTIR, EMP and XRD/SREF techniques. Our samples contain 0.14-0.65 wt.% B2O3. NMR reveals that B is predominantly present in trigonal coordination in the clinopyroxene structure. This observation is supported by vibrational bands characteristic for B-O stretching in BO3 groups in the range 1250-1400 cm−1 in polarised single crystal FTIR-spectra. Single crystal structure refinements suggest that boron replaces Si at the T site. Combined, these results suggest that boron replacement for Si at the T-site leads to disruption of one of the T-O bonds of the nominal clinopyroxene structure resulting in replacement of SiO4 tetrahedra by BO3 groups. Our results show that high concentrations of boron can be incorporated in the nominally boron-free diopside. Elevated B-concentrations in the present calcic clinopyroxenes are accompanied by modifications of the diopside crystal structure involving the breaking of one T-O bond and simultaneous formation of vacancies at the octahedral M2 site. These structural modifications destabilize the structure and constitute thereby limiting factors for incorporating higher boron concentrations in diopside. 相似文献
84.
Davide Farnocchia Giacomo Tommei Andrea Milani Alessandro Rossi 《Celestial Mechanics and Dynamical Astronomy》2010,107(1-2):169-185
We propose two algorithms to provide a full preliminary orbit of an Earth-orbiting object with a number of observations lower than the classical methods, such as those by Laplace and Gauss. The first one is the Virtual debris algorithm, based upon the admissible region, that is the set of the unknown quantities corresponding to possible orbits for a given observation for objects in Earth orbit (as opposed to both interplanetary orbits and ballistic ones). A similar method has already been successfully used in recent years for the asteroidal case. The second algorithm uses the integrals of the geocentric 2-body motion, which must have the same values at the times of the different observations for a common orbit to exist. We also discuss how to account for the perturbations of the 2-body motion, e.g., the J 2 effect. 相似文献
85.
Pietro Mosca Riccardo Polino Sergio Rogledi Massimo Rossi 《International Journal of Earth Sciences》2010,99(4):833-849
Alps and Apennines are juxtaposed within an approximately 100 km-wide area covered by the Upper Eocene to Miocene successions
of the Tertiary Piedmont Basin. The Upper Eocene–Oligocene evolution of this area was characterized to the north and west
by the propagation of the SE-verging Southalpine thrust-fold belt that can be traced from the Po Plain subsurface until the
Torino Hill-Saluzzese area, and to the south by a high-angle, broadly E–W oriented megashear zone that led to the juxtaposition
of different crustal levels and controlled the development of a mosaic of partly independent sub-basins. Since the latest
Oligocene the N-verging Apenninic tectonics prevailed in the collisional system and the Tertiary Piedmont Basin evolved as
a wide thrust-top basin, bounded to the north by the N-verging Monferrato arc and characterized by a tectono-sedimentary evolution
recording changes of subsidence and shift of depocentres in relation to crustal structures. 相似文献
86.
Currents and upwelling along the Latium coasts in the Central Tyrrhenian Sea (western Mediterranean)
In this study, springtime coastal currents along the Latium coast and their relation to external forcings, mainly wind stress curl and atmospheric pressure, are analysed. As a main result, we find that hydrographical measurements reveal currents parallel to the bottom isobaths, but with isopycnal sloping upwards towards the coast, suggesting the importance of upwellings in determining the coastal currents. This is confirmed by thermal satellite data showing the presence of a \sim10-km-wide patch of cold water east of Mount Argentario, i.e. a cyclonic vortex. The current meter data give rather small values of the time-averaged alongshore velocities (\sim2 cm s−1 for most current meters and \sim3 cm s−1 for the current meter placed immediately off the Argentario) and also smaller values for the offshore velocities. The correlation between these two types of currents is rather poor; this is also due to the variability characteristic of a wind-induced upwelling. Finally, we obtain a value of 0.74 for the correlation between the alongshore current (first mode of Empirical Orthogonal Functions decomposition) and the wind stress if a 23-h time lag is assumed. 相似文献
87.
An omphacite from the Nybø eclogite pod, Norway, has a chemical composition which plots within the gap, often regarded as a miscibility gap, which is evident in all previous compilations of natural jadeite-rich acmite-poor omphacite compositions. Its cation site populations determined by crystal structure refinement accord well with its chemical composition analysed by electron microprobe. Its disordered space group C2/c symmetry extends the known compositional range of C2/c pyroxene. The postulated miscibility gap is regarded as real and wide at low temperatures, but it appears to narrow with increasing temperature or ultimately with increasing acmite proportion. The adjacent primitive symmetry field appears to initially widen with increasing temperature or increasing acmite proportion, at the expense of the diminishing miscibility gap, before finally closing with further increase. 相似文献
88.
Summary Middle Triassic volcanic rock outcrops in the Mount Agnello area (Fiemme Valley, Italy) are examined in this study. Chemical analyses based on main and trace elements (Rb, Sr, Zr, Y, Nb) allow this volcanism to be defined as shoshonitic. The amphiboles, which occur with thick opacitic rims, were determined as ferroan pargasites. They were often found in volcanites of calcalkaline and/or shoshonitic associations. Consequently, this volcanism can be associated with a newly orogenized area undergoing stabilization. These data support the more recent studies on the mid-Triassic volcanism in the Southern Alps and underline the particular position of this magmatism in the tectonic evolution of this area.
With 4 Figures 相似文献
Les roches volcaniques de l'aire de Mont Agnello (Vallèe de Fiemme, Italie): Une contribution à la connaissance du volcanisme du trias moyen des Alpes Meridionales
Résumé Sont examinées les volcanites du Trias moyen affleurantes dans l'aire de Mont Agnello (Vallèe de Fiemme, Italie). Les déterminations du chimisme, en particulier celles regardant les éléments en traces (Rb, Sr, Zr, Y, Nb), revèlent pour ce volcanisme une affinité shoshonitique qui est bien associable à une aire de recente orogenèse en voie de stabilisation. On a aussi analysé l'amphibole, present dans ces roches, caracterisé par d'epais bords de réaction et on l'à reconnu comme une pargasite riche en fer. Ces amphiboles ont été retrouvé fréquemment dans des volcanites d'association calcoalcaline et/ou shoshonitique.
With 4 Figures 相似文献
89.
90.
Michel Durand-Delga Marie-José Fondecave-Wallez Philippe Rossi 《Comptes Rendus Geoscience》2005,337(12):1084-1095
The Jurassic N-MORB ophiolites of the Pineto Unit, which were unaffected by Alpine metamorphism, can be compared to the Apennine ophiolites. They are, however, distinguished by their cover rocks that include a silico-clastic flysch that we have dated as Albian–Cenomanian. Clastic deposits of the same type, but coarser grained, are known from the normal cover rocks of the Balagne Nappe E-MORB ophiolites, originally located on a thinned continental crust and/or near a continental margin. The Pineto Unit thus indicates that the detrital input of continental material was able to extend to a domain of clearly oceanic character in the Ligurian palaeo-ocean. To cite this article: M. Durand-Delga et al., C. R. Geoscience 337 (2005). 相似文献