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Comment: 3 pages, 2 figures, presented in ICPS-2006
Intraband transitions around 1.5 mum are studied in PbSe quantum dots at room temperature. Femtosecond pump-probe measurements reveal induced absorption by photoexcited carriers up to higher energy levels and its relaxation. A dominant decay component has a decay time of 10-40 ps, which is determined by the relaxation of carriers at the lowest absorption peak. The induced absorption is observed in a broad spectral range between 0.77 and 2.5 eV.
We study optical transitions from a periodic array of InP/InAs/InP core-multishell nanowires (CMNs) having a wurtzite crystal structure by using photoluminescence (PL) and PL excitation (PLE) spectroscopy. Observing a large Stokes shift between PL and PLE spectra, a blueshift of the PL peak with a cube-root dependence on the excitation power and a slow and nonexponential decay of PL with an effective decay time of 16 ns suggest a type-II band alignment. Band-offset calculation based on the "model-solid theory" of Van de Walle [Phys. Rev. B 39, 1871 (1989)] supports type-II band lineup if the InAs layer in the wurtzite CMNs is assumed to sustain compressive strain in all directions.
The East India Coastal Current (EICC) flows equatorward during October–December carrying low salinity water from the Bay of Bengal en route. Using results from a high resolution ocean general circulation model, satellite altimeter data, Argo float profiles and ocean color images we show that the EICC bifurcates east of Sri Lanka. One part continues along the coast of Sri Lanka but the major part of the EICC, called here as the East Sri Lanka Jet (ESLJ) flows eastward into the Bay of Bengal. As a result of this bifurcation, there is offshore transport of chlorophyll a rich low salinity water from the coast of Sri Lanka. Altimeter data from 1993–2004 show that the bifurcation occurred every year except during the Indian Ocean Dipole (IOD) years of 1994 and 1997. The bifurcation occurs when an anticyclonic eddy that propagates westward ah...
Interannual variations of sea surface temperature (SST) in the midlatitudes of the Southern Hemisphere play an important role in the rainfall variability over the surrounding countries by modulating synoptic-scale atmospheric disturbances. These are frequently associated with a northeast southwest-oriented dipole of positive and negative SST anomalies in each oceanic basin, referred to as a subtropical dipole. This study investigates the role of tropical SST variability on the generation of subtropical dipoles by conducting SST-nudging experiments using a coupled general circulation model. In the experiments where the simulated SST in each tropical basin is nudged to the climatology of the observed SST, the subtropical dipoles tend to occur as frequently as the case in which the simulated SST is allowed to freely interact with the atmo...
Comment: 20 pages with 9 figures, submitted to Semiconductor Science and Technology special issue on Optical Orientation
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