Application of fuzzy reasoning in an expert system for ultrasonography improves the diagnostic performance of inexperienced clinicians.

SUMMARY We have succeeded in synthesizing the zinc oxide (ZnO) microspheres by laser ablation of a ZnO sintered target in air, and have demonstrated ultraviolet whispering‐gallery‐mode lasting from the sphere under ultraviolet pulsed laser excitation. In this study, we investigated the dependence of the laser fluence and the spot size on the growth of the ZnO microspheres. Large sizes of more than 30 μm microspheres were synthesized with increasing the laser fluence up to 440 J/cm2. Although undesired nanoparticles and fragments were also generated at high fluence and large ablation spot size, selective collection of the microspheres can be expected because of different emitting distributions of the microspheres and other fragments.

We succeeded in synthesizing antimony (Sb)-doped zinc oxide (ZnO) microspheres by ablating a sintered ZnO target containing Sb in air. The structural properties of the microspheres were investigated by Raman scattering studies. The Zn–Sb related local vibrational mode (LVM) was detected around 238 cm−1. Room-temperature photoluminescence (PL) properties of the microspheres were investigated under cw and pulsed laser excitations, and ultraviolet (UV) emission and whispering-gallery-mode (WGM) lasing were observed from the microspheres. Furthermore, a p–n heterojunction was formed between a single Sb-doped ZnO microsphere and an n-Al-doped ZnO thin film, and a good rectifying property with a turn-on voltage of approximately 1.8 V was observed in the current–voltage (I–V) characteristics across the junction.

No abstract

No abstract