Surface transfer doping of hydrogen-terminated diamond probed by shallow nitrogen-vacancy centers

The surface conductivity of hydrogen-terminated diamond is a topic of great interest from both scientific and technological perspectives. This is primarily due to the fact that the conductivity is exceptionally high without the need for substitutional doping, thus enabling a wide range of electronic applications. Although the conductivity is commonly explained by the surface transfer doping due to air-borne surface acceptors, there remains uncertainty regarding the main determining factors that govern the degree of band bending and hole density, which are crucial for the design of electronic devices. Here, we elucidate the dominant factor influencing band bending by creating shallow nitrogen-vacancy (NV) centers beneath the hydrogen-terminated diamond surface through nitrogen ion implantation at varying fluences. We measured the photoluminescence and optically detected magnetic resonance of the NV centers as well as the surface conductivity as a function of the implantation fluence. Our findings indicate that band bending is not exclusively determined by the work-function difference between diamond and the surface acceptor material, but by the finite density of surface acceptors. Furthermore, this study also suggests the presence of spatial inhomogeneities in the surface conductivity and the charge state of the NV centers when the implantation fluence is close to the density of negatively charged surface acceptors. This work emphasizes the importance of distinguishing work-function-difference-limited band bending and surface-acceptor-density-limited band bending when modeling the surface transfer doping and provides useful insights for the development of devices based on hydrogen-terminated diamond

ダイオキシン モデル カゴウブツ ノ チョウオンパ ブンカイ

This paper presents some results of the research work aiming to find out a methodto decompose a dioxin-like compound. As a model, 4-chlorodiphenylether was chosen. Ultrasound energy in combination with Raney Ni catalyst was employed for this research. The best conversion of 4-chloro-diphenylether (>95%) was achieved for 20 kHz at 60 -C and O.lg Raney Ni.This combination of ultrasound and a catalyst is a promising one as a possible technique for dioxin decontamination

Stduy on residual fluoride materials in human body by fluoride analysis

科学研究費補助金研究成果報告書研究種目: 一般研究(C)研究期間: 1994～1995課題番号: 06672046研究代表者: 木村隆英（滋賀医科大学・医学部・助教授）研究分担者: 山本 学（滋賀医科大学・医学部・講師

Temperature Dependence of Zero-Bias Resistances of a Single Resistance-Shunted Josephson Junction

Zero-bias resistances of a single resistance-shunted Josephson junction are calculated as a function of the temperature by means of the path-integral Monte Carlo method in case a charging energy $E_{\rm C}$ is comparable with a Josephson energy $E_{\rm J}$. The low-temperature behavior of the zero-bias resistance changes around $\alpha=R_{\rm Q}/R_{\rm S}=1$, where $R_{\rm S}$ is a shunt resistance and $R_{\rm Q}=h/(2e)^2$. The temperature dependence of the zero-bias resistance shows a power-law-like behavior whose exponent depends on $E_{\rm J}/E_{\rm C}$. These results are compared with the experiments on resistance-shunted Josephson junctions

The PennState/Toru\'n Center for Astronomy Search for Planets Around Evolved Stars. Basic parameters of a sample of evolved stars

The objective of the PSU/TCfA Search for Planets Around Evolved Stars is to study evolution of planetary systems in the stellar evolution timescale. For such an analysis precise physical parameters of the hosts of the planetary systems are essential. In this paper we present an attempt to obtain basic physical parameters for a sample of evolved stars observed within our survey with the High Resolution Spectrograph of the Hobby-Eberly Telescope.Comment: 2 pages, to appear in "Extreme Solar Systems", 2007 ASP Conference Series, eds. Debra Fischer, Fred Rasio, Steve Thorsett and Alex Wolszcza

Wortmannin, a specific inhibitor of phosphatidylinositol-3 kinase, blocks osteoclastic bone resorption

AbstractThe biological role of phosphatidylinositol (PI)-3 kinase was examined in osteoclast-like multinucleated cells (OCLs) formed in co-cultures of mouse osteoblastic cells and bone marrow cells. The expression of PI-3 kinase in OCLs was confirmed by Western blot analysis. Wortmannin (WT), a specific inhibitor of PI-3 kinase, inhibited PI-3 kinase activity in OCLs both in vitro and in vivo. WT also inhibited pit-forming activity on dentine slices and disrupted a ringed structure of F-actin-containing dots (an actin ring) in OCLs in a dose-dependent manner. The inhibitory profiles of WT for pit and actin ring formation were similar to that for PI-3 kinase activity in OCLs. Electron microscopic analysis revealed that OCLs treated with WT did not form ruffled borders. Instead, numerous electron lucent vacuoles of differing sizes were found throughout the cytoplasm. These results suggest that PI-3 kinase is important in osteoclastic bone resorption