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111.
Carbon stripper foils having thicknesses in the range of 5–40 μg/cm2 have been prepared by a nitrogen ion beam sputtering method and their lifetimes have been tested in the Van de Graaff accelerator facility with 3.2 MeV, Ne+ ions. The foils of 21 μg/cm2 thickness had the longest mean lifetime of 1350.0 mC/cm2 (irradiation dose of 8.4×1018 atoms/cm2) which was 50 times longer than that of commercial foils. However, foils with other thicknesses had extremely short lifetimes similar to commercial foils. The nitrogen content of the foils of both long and short lifetimes has been determined using elastic scattering of 3 MeV α-particles. 相似文献
112.
Yoshiaki Hattori Shinobu Mukasa Hiromichi Toyota Shinfuku Nomura 《Current Applied Physics》2013,13(6):1050-1054
The electrical breakdown of microwave plasma in water was investigated between 1 and 30 kPa. The dependency of the ignition power for generating plasma on the size of coaxial electrode was measured. The ignition power decreases with a decrease of the diameter of the inner electrode. The behavior of microwave plasma in water was observed using a high-speed camera. The plasma ignites in a bubble generated by microwave heating. The model for calculating the electric field was created on the basis of the captured images of the bubble just before plasma ignition. The method presented can be used to visualize the electrical field distribution in the bubble. The electric field breakdown was calculated using the measured ignition power. The electric field breakdown of plasma in water is of the same order as gas phase plasma. 相似文献
113.
A. Ogura T. Yoshida Y. Kakemura M. Higuchi A. Teramoto T. Hattori 《Applied Surface Science》2008,254(19):6229-6231
The stresses at Si3N4/Si (1 0 0), (1 1 1) and (1 1 0) interfaces were measured by UV Raman spectroscopy with a 364 nm excitation laser whose penetration depth into the Si substrate was estimated to be 5 nm. The Si3N4 films were formed on Si (1 0 0), (1 1 1) and (1 1 0) using nitrogen-hydrogen (NH) radicals produced in microwave-excited high-density Xe/NH3 mixture plasma. The localized stress detected from Raman peak shift was compressive at the (1 0 0) interface, and tensile at the (1 1 1) and (1 1 0) interfaces. The results showed that stress had strong correlation with the total density of subnitrides at the Si3N4/Si interface, and also with the full-width at half-maximum (FWHM) of Si the 2p3/2 photoemission spectrum arising from the substrate. We believe that the localized stress affected subnitride formation because the amount of subnitride and the FWHM of Si 2p3/2 decreased while the interface stress shifted in the tensile direction. 相似文献
114.
Kazuki Komatsu Stefan Klotz Satoshi Nakano Shinichi Machida Takanori Hattori Asami Sano-Furukawa 《高压研究》2020,40(1):184-193
ABSTRACTA new high pressure cell for neutron diffraction experiments using nano-polycrystalline anvils is presented. The cell design, off-line pressure generation tests and a gas-loading procedure for this cell are described. The performance is illustrated by powder neutron diffraction patterns of ice VII to ~82?GPa. We also demonstrate the feasibility of single crystal neutron diffraction experiments of Fe3O4 at ambient conditions using this cell and discuss the current limitation and future developments. 相似文献
115.
116.
ABSTRACT To understand the practical effects of pressure-transmitting media (PTM) on neutron diffraction using Paris–Edinburgh presses, diffraction patterns of MgO were collected to approximately 20?GPa using PTMs of Pb, AgCl, 4:1 methanol–ethanol (ME) mixture with and without heating, N2, and Ar. Hydrostaticity in the sample chamber estimated from the MgO 220 peak width improves in the order of Pb, AgCl, Ar, ME mixture, N2, and the heated ME mixture. Unlike previous results using diamond anvil cells, the unheated ME mixture is superior to Ar even after freezing, probably due to the cup on the anvil face. Considering these results and the sizable coherent scattering of Ne, which would show good hydrostaticity, we conclude that the ME mixture (preferably the heated one) is the best PTM in neutron experiments up to 20?GPa, while Ar can be substituted when a sample is reactive to alcohols. 相似文献
117.
Dr. Yohei Hattori Shunsuke Tsubaki Dr. Ryota Matsuoka Dr. Tetsuro Kusamoto Prof. Hiroshi Nishihara Prof. Kingo Uchida 《化学:亚洲杂志》2021,16(17):2538-2544
Polychlorinated pyridyldiphenylmethyl radicals having substituents meta to the position bearing the carbon-centered radical (α-carbon) are synthesized. All of them are stable in ambient conditions in solutions and fluorescent in cyclohexane. The fluorescence of the radicals with bromo, phenyl, 4-chlorophenyl, or 2-pyridyl substituents are enhanced in chloroform, while the emission of the radicals with 2-thienyl or 2-furyl substituents are quenched in chloroform. DFT and TD-DFT calculations indicate that the first doublet excited states of the former are locally excited, while the first doublet excited states of the latter are charge transfer states from the π-electron-donating substituent to the accepting radical. The latter also show much higher photostability under 370-nm light irradiation compared with the first reported photostable fluorescent radical, (3,5-dichloro-4-pyridyl)bis(2,4,6-trichlorophenyl)methyl radical (PyBTM), with pronounced bathochromic shifts of the fluorescence. 相似文献
118.
Syntheses of (+)-altholactone isolated from Goniothalamus giganteus and its C-7 epimer (+)-7-epi-altholactone, (?)-etharvensin and (+)-alumheptolide-A were achieved. The lactone ring of these compounds was constructed using Pd-catalyzed carbonylation. 相似文献
119.
Mikihiro Ichikawa Shinya Yamamoto Chisato Ishihara Shuhei Nonobe Yasunao Hattori Koji Umezawa Hiroshi Fujii Hidefumi Makabe 《Tetrahedron》2018,74(27):3534-3542
Syntheses of epigallocatechin trimer, (epigallocatechin)2-epicatechin and (epigallocatechin)2-catechin were achieved. The key condensation to form the proanthocyanidin trimer derivatives was accomplished in a one-pot procedure using a dimeric epigallocatechin electrophile, which was prepared in situ by self-condensation of an epigallocatechin derivative, and an epigallocatechin, epicatechin, or catechin derivative as the nucleophile in the presence of a Lewis acid. The epigallocatechin monomer to trimer compounds containing a pyrogallol group significantly suppressed cell proliferation in PC-3 prostate cancer cells. 相似文献
120.
Araki Y Mukaisyo K Sugihara H Fujiyama Y Hattori T 《Journal of separation science》2008,31(15):2827-2830
In the present study, we developed a novel, simple, and specific detection method using an RP-HPLC at UV 285 nm for the separation and quantification of N-nitroso-bile acids. First, we found that N-nitroso-bile acids have a specific spectrophotometric absorbance at 285 nm. Using this 285 nm detection system, we could especially measure N-nitroso-bile acids, even in co-existence of non-N-nitroso-bile acids. Next, we observed the decomposition of N-nitroso-glychocholate under alkaline, acidic, and neutral conditions. N-nitroso-glychocholate rapidly decomposed under alkaline conditions (pH 9) (t(1/2) = 0.96 h), but remained fairly stable under acidic (pH 2) (t(1/2) = 12.8 h) and neutral (pH 7) (t(1/2) = 7.8 h) conditions. This study is the first report, which simply and specifically analyzes N-nitroso-bile acids using an RP-HPLC system. 相似文献