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- Flanagan, K. T., et al.
(författare)
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Nuclear Spins and Magnetic Moments of Cu-71,Cu-73,Cu-75 : Inversion of pi 2p(3/2) and pi 1f(5/2) Levels in Cu-75
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 103:14, s. 142501-
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Tidskriftsartikel (refereegranskat)abstract
- We report the first confirmation of the predicted inversion between the pi 2p(3/2) and pi 1f(5/2) nuclear states in the nu g(9/2) midshell. This was achieved at the ISOLDE facility, by using a combination of in-source laser spectroscopy and collinear laser spectroscopy on the ground states of Cu-71,Cu-73,Cu-75, which measured the nuclear spin and magnetic moments. The obtained values are mu(Cu-71)=+2.2747(8)mu(N), mu(Cu-73)=+1.7426(8)mu(N), and mu(Cu-75)=+1.0062(13)mu(N) corresponding to spins I=3/2 for Cu-71,Cu-73 and I=5/2 for Cu-75. The results are in fair agreement with large-scale shell-model calculations.
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- Forest, F., et al.
(författare)
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The role of biotic and abiotic factors in evolution of ant dispersal in the milkwort family (Polygalaceae)
- 2007
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 61:7, s. 1675-1694
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Tidskriftsartikel (refereegranskat)abstract
- A phylogenetic approach was taken to investigate the evolutionary history of seed appendages in the plant family Polygalaceae (Fabales) and determine which factors might be associated with evolution of elaiosomes through comparisons to abiotic (climate) and biotic (ant species number and abundance) timelines. Molecular datasets from three plastid regions representing 160 species were used to reconstruct a phylogenetic tree of the order Fabales, focusing on Polygalaceae. Bayesian dating methods were used to estimate the age of the appearance of ant-dispersed elaiosomes in Polygalaceae, shown by likelihood optimizations to have a single origin in the family. Topology-based tests indicated a diversification rate shift associated with appearance of caruncular elaiosomes. We show that evolution of the caruncular elaiosome type currently associated with ant dispersal occurred 54.0-50.5 million year ago. This is long after an estimated increase in ant lineages in the Late Cretaceous based on molecular studies, but broadly concomitant with increasing global temperatures culminating in the Late Paleocene-Early Eocene thermal maxima. These results suggest that although most major ant clades were present when elaiosomes appeared, the environmental significance of elaiosomes may have been an important factor in success of elaiosome-bearing lineages. Ecological abundance of ants is perhaps more important than lineage numbers in determining significance of ant dispersal. Thus, our observation that elaiosomes predate increased ecological abundance of ants inferred from amber deposits could be indicative of an initial abiotic environmental function.
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- Forest, M. G., et al.
(författare)
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On the exact solution for smooth pulses of the defocusing nonlinear Schrodinger modulation equations prior to breaking
- 2009
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Ingår i: Nonlinearity. - : IOP Publishing. - 1361-6544 .- 0951-7715. ; 22:9, s. 2287-2308
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Tidskriftsartikel (refereegranskat)abstract
- The modulation equations for the amplitude and the phase of the defocusing nonlinear Schrodinger (NLS) equation in the semi-classical limit are solved exactly for smooth pulse initial data using an implicit hodograph representation of Tsarev (1985 Sov. Math.-Dokl. 31 448) combined with an extension of Riemann's method on multi-sheeted characteristic planes developed by Ludford (1952 Proc. Camb. Phil. Soc. 48 499-510, 1954 J. Ration. Mech. 3 77-88). Our results extend previous exact solutions of the modulation equations for piecewise step function data (Biondini and Kodama 2006 J. Nonlinear Sci. 16 435-81, Kodama and Wabnitz 1995 Opt. Lett. 20 2291-3, Kodama 1999 SIAM J. Appl. Math. 59 2162-92) and for smooth monotone data (Wright et al 1999 Phys. Lett. A257 170-4) to more physically relevant smooth pulse data (a finite number of pulses). Our results also provide an exact characterization of the estimates for smooth pulse data of first breaking time and location, previously based on analysis of the modulation equations as hyperbolic conservation laws (Forest and McLaughlin 1998 J. Nonlinear Sci. 7 43-62). Extensions to other integrable nonlinear equations of NLS-type are also discussed in the appendix.
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