Results 231 to 240 of about 4,970,662 (269)
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1986
We argue that the solar-system σN curve can be best understood if the s-process is largely produced by stars in the mass range of M ∿ 2–4 MO. Several observations are then studied as indicators of the validity of this hypothesis. We find that isotopic Zr abundances and elemental (Ba/Sr) vs. (Ba/Nd) ratios are consistent with these conditions.
G. J. Mathews +3 more
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We argue that the solar-system σN curve can be best understood if the s-process is largely produced by stars in the mass range of M ∿ 2–4 MO. Several observations are then studied as indicators of the validity of this hypothesis. We find that isotopic Zr abundances and elemental (Ba/Sr) vs. (Ba/Nd) ratios are consistent with these conditions.
G. J. Mathews +3 more
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Mechanism of Allosteric Regulation of Dnmt1's Processivity
Biochemistry, 2005We have analyzed the relationship between the allosteric regulation and processive catalysis of DNA methyltransferase 1 (Dnmt1). Processivity is described quantitatively in terms of turnover rate, DNA dissociation rate, and processivity probability. Our results provide further evidence that the active site and the allosteric sites on Dnmt1 can bind DNA
Zeljko M, Svedruzić, Norbert O, Reich
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Formalizing Semantics of OWL-S Process Model
2008 IEEE Pacific-Asia Workshop on Computational Intelligence and Industrial Application, 2008OWL-S is an important standard for semantic web and its process model not formalized complete. There are some researches working on formalizing semantics of OWL-S process model and this paper is one of them. Rewrite logic system Maude is choose to formalize the informal part semantics of OWL-S in our work.
Ning Huang, YongYi Peng, Ning Huang
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Nuclear uncertainties in the s-process simulation
Science China Physics, Mechanics and Astronomy, 2013The heavy elements in the Universe are formed during the s- and r-processes mainly in AGB stars and supernovae, respectively. Simulation of s- and r-nucleosynthesis critically depends on the neutron capture and weak decay rates for all the nuclei on the reaction chain.
YouJin Zhang +5 more
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The s-Process: Branchings and Chronometers
1991This contribution presents a discussion of the various potential ?-process chronometers. In principle, this means that one compares the observed abundance of an unstable isotope or of its daughter nucleus with the original abundance by which they were produced in the slow neutron capture process (s-process).
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The s-process of stellar nucleosynthesis
Progress in Particle and Nuclear Physics, 1986Abstract The present status of our understanding of the s process of stellar nucleosynthesis is reviewed from the point of view of nuclear physics. Observed abundances of chemical elements and their isotopes are combined with information on neutron capture cross sections and nuclear structure.
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Survival of 180Ta at s-process temperatures
Nuclear Physics A, 1997Abstract The photodeexcitation of 180 Ta m was studied by means of the Coulomb excitation mechanism using protons and α-particles as projectiles. No evidence for an intermediate state below 1 MeV, as recently reported, was found, thus, infering an s-process origin of 180 Ta.
M. Schumann +3 more
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The Weak s‐Process at Low Metallicity
AIP Conference Proceedings, 2008We present a sample of s‐process calculations at solar metallicity and at halo metallicity. First, for a 25 M⊙ we report the weak s‐process contribution to the elements between Co and Mo in the solar system. More than 50% of solar Cu, Ga, Ge and As is reproduced, and most of the solar elements between Fe and Sr receives a contribution higher than 10 ...
M. Pignatari, R. Gallino
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QCD corrections to charmlessb→s processes
Zeitschrift für Physik C: Particles and Fields, 1995QCD corrections to the penguin induced charmless inclusiveB decays are performed to an improved leading-log approximation. For processb→sqq (q=uds) andbb→ss, four previous missed 4-quark operators are included to make a complete leading log QCD corrected result. Furthermore, part of the next-leading log effect was also given for the above processes and
Chong Shou Gao +2 more
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The s-Process Elements Cadmium and Tin
1999The data used for this study were high signal-to-noise absorption spectra of the Cd II 2145 A and Sn II 1400 A transitions observed with the HST’s Goddard High Resolution Spectrograph.
Ulysses J. Sofia, David M. Meyer
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