134 research outputs found
Stripe antiferromagnetic correlations in LaFeAsO1-xFx probed by 75As NMR
The anisotropy of the nuclear spin-lattice relaxation rate of
As was investigated in the iron-based superconductor
LaFeAs(OF) ( and 0.14) as well as LaFeAsO. While
the temperature dependence of the normal-state in the superconducting
(SC) is different from that in the SC , their anisotropy
of , in
the normal state is almost the same ( 1.5). The observed anisotropy is
ascribable to the presence of the local stripe correlations with
or . In contrast, is isotropic and is approximately 1 in
the overdoped sample, where superconductivity is almost suppressed.
These results suggest that the presence of the local stripe correlations
originating from the nesting between hole and electron Fermi surfaces is linked
to high- superconductivity in iron pnictides.Comment: 4 pages, 3 figures, Accepted for publication in Phys. Rev.
Eleven-year, 22-year and ~90-year solar cycles discovered in nitrate concentrations in a Dome Fuji (Antarctica) ice core
Ice cores are known to yield information about astronomical phenomena as well
as information about past climate. We report time series analyses of annually
resolved nitrate variations in an ice core, drilled at the Dome Fuji station in
East Antarctica, corresponding to the period from CE 1610 to 1904. Our analyses
revealed clear evidence of ~11, ~22, and ~90 year periodicities, comparable to
the respective periodicities of the well-known Schwabe, Hale, and Gleissberg
solar cycles. Our results show for the first time that nitrate concentrations
in an ice core can be used as a proxy for past solar activity on decadal to
multidecadal time scales. Furthermore, 11-year and 22-year periodicities were
detected in nitrate variations even during the Maunder Minimum (1645-1715),
when sunspots were almost absent. This discovery may support cyclic behavior of
the solar dynamo during the grand solar minimum.Comment: Submitted to Proceedings of the Japan Academy, Series
Annually-resolved water isotope measurements in a shallow ice core (DFS10) for 60 meters depth
The Tenth Symposium on Polar Science/Ordinary sessions: [OM] Polar Meteorology and Glaciology, Wed. 4 Dec. / Entrance Hall (1st floor) , National Institute of Polar Researc
Chemical composition and their characteristics of shallow ice cores drilled at Dome Fuji, East Antarctica
第3回極域科学シンポジウム 横断セッション「海・陸・氷床から探る後期新生代の南極寒冷圏環境変動」11月27日(火) 国立国語研究所 2階講
- …