We fabricated intrinsic Josephson junctions 10 /spl mu/m/spl times/10 /spl mu/m in area using Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ (Bi-2212) thin films with large grains employing a two-step annealing procedure. The first annealing step at a high temperature in O/sub 2/ is for the growth of crystal grains and the second step at a lower temperature in N/sub 2/ is for the control of the oxygen content in the film. By this method, Bi-2212 thin films with the c-axis critical current density J/sub c/ of 10/sup 1/-10/sup 4/ A/cm/sup 2/ were obtained. A mesa structure was formed on the surface of the annealed film and we measured its electrical properties along the c-axis. The current-voltage characteristics with clear hystereses and multiple branches were observed for the samples with J/sub c/ of /spl sim/10/sup 3/ A/cm/sup 2/ or less. The gap structure was observed in the current-voltage characteristics for low mesas. J/sub c/ and the voltage jump decreased more rapidly with increasing temperature than those predicted by the BCS theory. We could obtain intrinsic Josephson junctions in Bi-2212 thin films with similar properties as in single crystal samples.
We presented a case of left anterior descending coronary artery aneurysm that was developed after percutaneous coronary intervention (PCI) with stent implantation. The aneurysm was plicated after removal of the stent device, and the left descending coronary artery was bypassed with the left internal thoracic artery. Few have reported surgical treatments for the coronary aneurysm including PCI stent. In this report, a patient requiring PCI stent explantation was described and technical considerations for this patient were discussed.
We demonstrate a single-channel 40-Gbit/s QAM quantum stream cipher transmission over 480-km. By using a multi-bit encoded scheme and digital coherent transmission techniques, record data capacity and transmission distance of secure optical communication have been successfully realized.
Tb-doped Y2SiO5 (YSO:Tb) phosphor particles having a mean particle size of more than 2 µm and a narrow particle size distribution were prepared by spray pyrolysis using a two-fluid nozzle spray generator (marked SPs), and their crystallinity, photoluminescence (PL), and cathodeluminescence (CL) intensity were compared with those of YSO:Tb phosphor particles prepared using the sol–gel method (marked Sol-gel). It was found that non agglomerated precursor particles were formed by controlling the pyrolysis temperature and that the particle size distribution for SPs was much narrower than that for Sol-gel. In addition, the mean particle size of the SPs was changed by controlling the spray and carrier gas flow rates. An accurate X-ray diffraction Rietveld (XRD-Rietveld) analysis was successfully performed by using a cellulose resin; it was found that the crystallinity for SPs was as good as that for Sol-gel. The luminescence efficiency evaluated by the PL measurement for a certain condition of SPs (marked SP-2) was more or less the same as that for Sol-gel. On the other hand, the CL intensity for SP-2 was 15% higher than that for Sol-gel because of the former's uniformly and densely packed CL measurement plate arranged using phosphor particles having a narrow particle size distribution.
