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Browsing ELibrary by Title
Now showing items 7-26 of 21934
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(1996)133Cs MAS NMR of Cs-exchanged illite, kaolinite, boehmite, and silica gel is shown to be a powerful tool to investigate the adsorption sites and atomic dynamics of Cs on mineral surfaces. Cesium is adsorbed on these mineral ...
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(1991)13C-enriched glasses of albite, nepheline, and sodamelilite compositions were quenched from melts at 1350–1625°C and 10–35 kb, and studied using 13C and 27A1 MAS NMR. Distinct resonances for molecular CO2 and carbonate ...
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(2006)The abundance of the doubly substituted CO2 isotopologue, 13C18O16O, in CO2 produced by phosphoric acid digestion of synthetic, inorganic calcite and natural, biogenic aragonite is proportional to the concentration of ...
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(1998)The stable isotopic composition of marine dissolved organic carbon (DOC) was measured with a high temperature, sealed tube combustion technique. The δ13C values of DOC (DO13C) were approximately -22%% for all samples that ...
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(1995)Now-extinct 146Sm (t1 = 103 Ma) was present in the early solar system, and lunar basalts might be expected to have inherited small anomalies in 142Nd abundances from mantle sources with variable Sm/Nd ratios established ...
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(2002)The 147Sm-143Nd and 176Lu-176Hf systematics of 21 whole-rock eucrites, including five cumulates, have been investigated by MC-ICP-MS. A statistically significant Sm-Nd isochron was obtained on 18 samples with an age of ...
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(1999)Prompted by the finding that the eucrite Piplia Kalan could have retained Pu fission Xe earlier than the eucrites so far studied and hence be very ancient, we have measured a precise internal 147Sm-143Nd isochron for this ...
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(1998)Accelerator mass spectrometry (AMS) was used to measure the activity vs. depth profiles of 14C produced by both solar cosmic rays (SCR) and galactic cosmic rays (GCR) in Apollo 15 lunar cores 15001-6 and 15008, Apollo 17 ...
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(2000)We report here the first nuclear magnetic resonance (NMR) spectroscopic study of the dynamical and structural behavior of nitrate on the surface and in the interlayer of hydrotalcite-like compounds (15NO3--HT). Spectroscopically ...
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(2000)The oxygen isotopic compositions of seven Al-rich chondrules from four unequilibrated ordinary chondrites were measured in situ using an ion microprobe. On an oxygen three isotope plot, the data are continuous with the ...
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(2001)A problem of long-standing is the origin of the high Δ17O (= δ17O - 0.52 . δ18O) values of melilite in the refractory inclusions of carbonaceous chondrites. The spinel and, usually, also the diopside in the inclusions have ...
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(2001)17α,21α(H)-hopanes are found in low concentrations in sediments and oils, but C30 17α,21α(H)-hopane is the only member of the series which can be detected in the m/z 191 mass chromatogram. The ratio of C30 17α,21α(H)-hopane ...
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(2000)Eucrites are the witnesses of an early magmatic activity in small planetary bodies. Iron meteorites also testify to an early differentiation in planetesimals. Are basaltic magmatism and iron segregation related to each ...
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(1998)W isotopic compositions (measured by N-TIMS) in five iron meteorite groups are used in conjunction with 187Re-187Os isotopic data to constrain the timing of metal segregation and crystallization, respectively, in the iron ...
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(2001)The Re–Os data on Archean komatiites from the Kostomuksha greenstone belt in the Baltic Shield are presented. This greenstone belt has been previously interpreted to represent a former oceanic plateau formed by the emplacement ...
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(2004)The chemistry and budgets of atmospheric gases are constrained by their bulk stable isotope compositions (e.g., δ13C values), which are based on mixing ratios of isotopologues containing one rare isotope (e.g., 16O13C16O). ...
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18O/16O ratios in anhydrous spinel lherzolite xenoliths from the Shavaryn-Tsaram volcano, Mongolia (1987)Anhydrous spinel lherzolite xenoliths from the Shavaryn-Tsaram volcano, which represent unusually clinopyroxenerich samples of upper mantle beneath the Tariat Depression in north-central Mongolia, have particularly low ...
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(2005)The Inner Carpathians comprise several distinct Neogene late-stage orogenic Pb-Zn-Cu-Ag-Au ore districts. The mineral deposits in these districts are closely related to volcanic and subvolcanic rocks, and represent mainly ...
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(2003)Images of the depth and shape of colluvial wedges by 3-D travel time tomography can be valuable in estimating the past history of ancient earthquakes and assessing the earthquake hazard of a fault. Unfortunately, 3-D seismic ...
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(2003)studied the two-dimensional (2-D) rotational behaviour of individual rigid particles embedded in a viscous medium subject to simple shear and transpression (Sr>0), at low/medium shear strains. We now extend this theoretical ...
Now showing items 7-26 of 21934