610 research outputs found
Femtosecond Excitation Correlation Spectroscopy of Single-Walled Carbon Nanotubes : Analysis Based on Nonradiative Multiexciton Recombination Processes
We studied the nonlinear time-resolved luminescence signals due to
multiexciton recombination processes in single-walled carbon nanotubes (SWNTs)
using femtosecond excitation correlation (FEC) spectroscopy. From theoretical
analysis of the FEC signals, we found that the FEC signals in the long time
range are dominated by the single exciton decay in SWNTs, where the
exciton-exciton annihilation process is efficient. Our results provide a simple
method to clarify the single exciton decay dynamics in low-dimensional
materials.Comment: 21 pages, 5 figures; typos adde
ABO-Incompatible Kidney Transplantation
Previously, ABO-incompatible kidney transplantation (KTx) was believed to be a “taboo” for immunological reasons. In Japan, the Tokyo Women’s Medical University reported the first successful case of such transplantation, performed on January 19, 1989. Since then, we have been striving to improve the outcome of ABO-incompatible transplantation for a quarter of a century
Effect of Dy substitution in the giant magnetocaloric properties of HoB
Recently, a massive magnetocaloric effect near the liquefaction temperature
of hydrogen has been reported in the ferromagnetic material HoB. Here we
investigate the effects of Dy substitution in the magnetocaloric properties of
HoDyB alloys ( = 0, 0.3, 0.5, 0.7, 1.0). We
find that the Curie temperature () gradually increases upon
Dy substitution, while the magnitude of the magnetic entropy change || at = decreases from 0.35 to 0.15
J cm K for a field change of 5 T. Due to the presence of two
magnetic transitions in these alloys, despite the change in the peak magnitude
of ||, the refrigerant capacity () and
refrigerant cooling power () remains almost constant in all
doping range, which as large as 5.5 J cm and 7.0 J cm for a field
change of 5 T. These results imply that this series of alloys could be an
exciting candidate for magnetic refrigeration in the temperature range between
10-50 K.Comment: 19 pages, 5 figures, 2 table
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