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Results 1 - 10
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2,076
Europium, Samarium, and Neodymium Isotopic Fractions in Metal-Poor Stars
"... Abstract. We have derived isotopic fractions of europium (Eu), samarium (Sm), and neodymium (Nd) in two metal-poor giants with differing neutron-capture nucleosynthetic histories. These isotopic fractions were measured from new very high resolution {R- ^ 120,000), high signal-to-noise (S/N- ^ 160 — ..."
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Abstract. We have derived isotopic fractions of europium (Eu), samarium (Sm), and neodymium (Nd) in two metal-poor giants with differing neutron-capture nucleosynthetic histories. These isotopic fractions were measured from new very high resolution {R- ^ 120,000), high signal-to-noise (S/N- ^ 160
Europium Isotope Ratios in s-Process-Element-Enhanced, Metal-Poor Stars: A New Probe of the 151 Sm Branching 1
, 2003
"... We report on the first measurement of the Eu isotope fractions ( 151 Eu and 153 Eu) in s-process-element-enhanced, metal-poor stars. We use these ratios to investigate the 151 Sm branching of s-process nucleosynthesis. The measurement was made by detailed study of Eu II lines that are significantly ..."
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We report on the first measurement of the Eu isotope fractions ( 151 Eu and 153 Eu) in s-process-element-enhanced, metal-poor stars. We use these ratios to investigate the 151 Sm branching of s-process nucleosynthesis. The measurement was made by detailed study of Eu II lines that are significantly
The barium isotopic fractions in five metal-poor stars
, 2013
"... Context. Theory and observations of heavy element nucleosynthesis are in conflict with one-another. Theory states that in the most metal-poor stars, the rapid (r-) neutron-capture nucleosynthetic process would be dominant over the slow (s-) process. The most recent determinations of r- and s-process ..."
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-process yields do not support this. Aims. We provide measurements of the Ba isotopic fractions for five metal-poor stars derived with a local thermodynamic equilibrium (LTE) analysis with 1D model stellar atmospheres. This increases the comparisons with heavy element nucleosynthesis theory. Methods. We use high
Chemical differentiation of the Earth: the relationship between mande, continental crust, and oceanic crust.
- Earth Planet. Sci. Lett.,
, 1988
"... The average chemical compositions of the continental crust and the oceanic crust (represented by MORB), normalized to primitive mantle values and plotted as functions of the apparent bulk partition coefficient of each element, form surprisingly simple, complementary concentration patterns. In the c ..."
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Cited by 177 (2 self)
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concentration maximum in MORB. It yields quantitative constraints about the effective aggregate melt fractions extracted during both stages. These amount to about 1.5% for the continental crust and about 8-10% for the oceanic crust. The comparatively low degrees of melting inferred for average MORB
Isotope
"... fractionation and sulfur metabolism by pure and enrichment cultures of elemental sulfur-disproportionating bacteria ..."
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fractionation and sulfur metabolism by pure and enrichment cultures of elemental sulfur-disproportionating bacteria
On the hyperfine anomaly in Eu isotopes
, 2009
"... A new method for determining the hyperfine anomaly, without knowing the nuclear magnetic moment, is used for the first time on a series of unstable isotopes. The relative large number of experimental data in Eu makes it possible to determine the hyperfine anomaly for a number of unstable isotopes. C ..."
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A new method for determining the hyperfine anomaly, without knowing the nuclear magnetic moment, is used for the first time on a series of unstable isotopes. The relative large number of experimental data in Eu makes it possible to determine the hyperfine anomaly for a number of unstable isotopes
Isotopic fractionation of water during evaporation
- Journal of Geophysical Research-Atmospheres
, 2003
"... [1] Variations in the isotopic content (18O/16O and D/H ratios) of water in the natural environment provide a valuable tracer of the present-day global hydrologic cycle and a record of the climate over at least 400,000 years that is preserved in glacial ice. The interpretation of observed isotopic r ..."
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Cited by 23 (0 self)
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ratios in water vapor, rain, snow, and ice depends on our understanding of the processes (mainly phase changes) that produce isotopic fractionation. Whereas equilibrium isotopic fractionation is well understood, kinetic effects, or diffusion-controlled fractionation, has a limited experimental foundation
Carbon and Oxygen Isotope Fractionation in
"... The present heories on the fractionation of stable isotopes in scleractinian corals are critically discussed in the light of data available on primary productivity, respiration and stable isotope chemistry. These data support a model of fractionation i which the carbon and oxygen isotopes are decoup ..."
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The present heories on the fractionation of stable isotopes in scleractinian corals are critically discussed in the light of data available on primary productivity, respiration and stable isotope chemistry. These data support a model of fractionation i which the carbon and oxygen isotopes
L.: Photo-induced isotopic fractionation
- J. Geophys. Res
"... Abstract. This paper presents a systematic method for the analysis of photo-induced isotopic fi'actionation. The physical basis for this fractionation mechanism centers on the fact that isotopic substitution alters the energy levels, molecular symmetries, spin statistical weights and other f•md ..."
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Cited by 9 (0 self)
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Abstract. This paper presents a systematic method for the analysis of photo-induced isotopic fi'actionation. The physical basis for this fractionation mechanism centers on the fact that isotopic substitution alters the energy levels, molecular symmetries, spin statistical weights and other f
Results 1 - 10
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2,076
