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Iijima, Kazuki; Tomura, Tsutomu*; Tobita, Minoru*; Suzuki, Yasuyuki*
Radiochimica Acta, 98(9-11), p.729 - 736, 2010/11
Times Cited Count：3 Percentile：17.46(Chemistry, Inorganic & Nuclear)Distribution behavior of Cs and Am in the synthetic groundwater-bentonite colloids-granite ternary system was investigated. Radionuclide sorbed onto the bentonite colloids is desorbed by addition of granite, indicating that the sorption of Cs and Am onto the bentonite colloids are reversible. The sorption model based on cation exchange and surface complexation reaction considering high edge site density for bentonite colloids is applicable to explain the sorption behavior of Am and Cs in the ternary system.
Hasegawa, Shin; Sato, Ken*; Narita, Tadashi*; Suzuki, Yasuyuki; Takahashi, Shuichi; Morishita, Norio; Maekawa, Yasunari
Journal of Membrane Science, 345(1-2), p.74 - 80, 2009/12
Times Cited Count：33 Percentile：70.33(Engineering, Chemical)Radiation-induced graft polymerization of styrene into poly(ether ether ketone) (PEEK) with 32% crystallinity was investigated with DSC, TGA, XRD, and ESR. Endothermic heats of melting of the original and styrene-grafted PEEK (grafted PEEK) films were similar, indicating the crystallinity was almost completely maintained up to a grafting degree of 51%. Lower glass transition temperature of the grafted PEEK film in the DSC, and the absence of an extra halo originating from amorphous polystyrene grafts in the XRD strongly indicate the grafting of styrene to crystalline PEEK films proceeded in the amorphous region of PEEK. This is probably because polystyrene grafts have hydrocarbon structures similar to a base PEEK polymer, resulting in compatibility to the amorphous phase of the PEEK films. The grafted PEEK films can be converted to PEEK-based electrolyte membranes by subsequent sulfonation, and had conductivity of more than 0.01 S/cm and exhibited higher water content above 100%.
Hasegawa, Shin; Suzuki, Yasuyuki; Maekawa, Yasunari
Radiation Physics and Chemistry, 77(5), p.617 - 621, 2008/05
Times Cited Count：39 Percentile：90.88(Chemistry, Physical)Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2 
2.9 mmol/g and 0.03 0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting.
Yamasaki, Chisato*; Murakami, Katsuhiko*; Fujii, Yasuyuki*; Sato, Yoshiharu*; Harada, Erimi*; Takeda, Junichi*; Taniya, Takayuki*; Sakate, Ryuichi*; Kikugawa, Shingo*; Shimada, Makoto*; et al.
Nucleic Acids Research, 36(Database), p.D793 - D799, 2008/01
Times Cited Count：51 Percentile：71.25(Biochemistry & Molecular Biology)Here we report the new features and improvements in our latest release of the H-Invitational Database, a comprehensive annotation resource for human genes and transcripts. H-InvDB, originally developed as an integrated database of the human transcriptome based on extensive annotation of large sets of fulllength cDNA (FLcDNA) clones, now provides annotation for 120 558 human mRNAs extracted from the International Nucleotide Sequence Databases (INSD), in addition to 54 978 human FLcDNAs, in the latest release H-InvDB. We mapped those human transcripts onto the human genome sequences (NCBI build 36.1) and determined 34 699 human gene clusters, which could define 34 057 protein-coding and 642 non-protein-coding loci; 858 transcribed loci overlapped with predicted pseudogenes.
-phenylene terephthalamide); Control of pore shape by irradiation with different ion beamsSuzuki, Yasuyuki; Yamaki, Tetsuya; Koshikawa, Hiroshi; Asano, Masaharu; Voss, K.-O.*; Neumann, R.*; Yoshida, Masaru
Nuclear Instruments and Methods in Physics Research B, 260(2), p.693 - 695, 2007/07
Times Cited Count：13 Percentile：66.15(Instruments & Instrumentation)The preparation of ion-track membranes of thermally stable poly(p-phenylene terephthalamide) was performed by ion beam irradiation followed by chemical etching with a sodium hypochlorite solution. Cylindrical pores were observed in the membrane irradiated with 
Au and 
U ions at an energy of 11.1 MeV/n. In contrast, funnel shape pores appeared in the membrane irradiated with 
Kr, 
Ru and 
Xe ion at energies of 6.2, 3.6 and 3.5 MeV/n, respectively. The Au and U ion irradiation was found to exhibit more than four times larger sensitivity to the track etching under the same etching conditions. Consequently, the pore shape can be controlled by the masses and energies of the irradiated ions, in close relation to the etching sensitivity of the track.
-phenylene terephthalamide)Yamaki, Tetsuya; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Yasuyuki; Yoshida, Masaru; Neumann, R.*; Voss, K.-O.*
GSI Report 2007-1, P. 332, 2007/06
The preparation of ion-track membranes of thermally stable poly(-phenylene terephthalamide) (PPTA) was performed by ion beam irradiation followed by chemical etching with a sodium hypochlorite solution. Cylindrical pores were observed in the membrane irradiated with Au and U ions at an energy of 11.1 MeV/n. In contrast, funnel shape pores appeared in the membrane irradiated with Kr, Ru and Xe ion at energies of 6.2, 3.6 and 3.5 MeV/n, respectively. The effect of the ion velocity as well as of the LET in the damage creation might be manifested for the present etched tracks.
Maekawa, Yasunari; Suzuki, Yasuyuki; Maeyama, Katsuya*; Yonezawa, Noriyuki*; Yoshida, Masaru
Langmuir, 22(6), p.2832 - 2837, 2006/03
Times Cited Count：6 Percentile：30.05(Chemistry, Multidisciplinary)Chemical modification of the internal surfaces of cylindrical pores with sub-micrometer of pore diameter in PET film was examined. The modification involved the alkylation of the carboxylic acid on the surfaces with the alkylation reagent containing a fluorescent probe, and it was monitored by observing the change in fluorescent emission intensity. When the DMF solution of 4-(bromomethyl)-6,7-dimethoxycoumarin (BrCU), which bore a coumarin fluorophore, was introduced into the pores, the emission and excitation intensities of the membranes increased proportionally with increases of the pore surface areas. Fluorescent spots of about 300 nm in diameter, which were located at the positions of the pores, can be observed in the fluorescence microscope image of the membranes, indicating that highly concentrated fluorescent probes are chemically incorporated on the internal surfaces of the cylindrical pores with 210 nm in diameter in the membranes. In the reactions of the PET surfaces with BrCU, the fluorescent intensities increased with increases of the contact angles. This result indicates that the hydrophilicity of the internal pore surfaces can be qualitatively modified by controlling the change in the fluorescent intensities.
Hiroki, Akihiro; Suzuki, Yasuyuki; Yamaki, Tetsuya; Asano, Masaharu; Yoshida, Masaru
Hoshasen To Sangyo, (108), p.4 - 8, 2005/12
no abstracts in English
Zhu, Z.; Maekawa, Yasunari; Koshikawa, Hiroshi; Suzuki, Yasuyuki; Yonezawa, Noriyuki*; Yoshida, Masaru
Nuclear Instruments and Methods in Physics Research B, 217(3), p.449 - 456, 2004/05
Times Cited Count：20 Percentile：76.55(Instruments & Instrumentation)The pretreatment effects using UV light illumination and DMF soaking on bulk and track etching rates of PET films were investigated. The wavelength of illuminated UV light plays an important role in sensitizing track etching. Illumination with the light at wavelengths longer than 320nm showed strong enhancement in the track etching rates without influence on the bulk etching rates, whereas light with the wavelengths lower than 320nm causes large enhancement in both track and bulk etching rates even in the interior of the material. The track etching rate is found to be not constant along ion tracks, which is attributed to the inhomogeneous distribution of reactive chemical species induced during post-UV light illumination. Furthermore, the DMF soaking of PET after UV light illumination can enhance the etching sensitivity of the track by more than 100 times. The phenomenon is attributed to the high diffusion of organic solution along tracks after UV light illumination.
Maekawa, Yasunari; Suzuki, Yasuyuki; Maeyama, Katsuya*; Yonezawa, Noriyuki*; Yoshida, Masaru
Chemistry Letters, 33(2), p.150 - 151, 2004/02
Times Cited Count：4 Percentile：21.74(Chemistry, Multidisciplinary)Since well-characterized chemical modification of pore inner surfaces in polymer membranes should be very important from the view point of synthetic chemistry of polymer surfaces as well as designing materials for application such as separation membranes and nanoscopic electronic devices, we reported herein the chemical modification of internal surfaces of the cylindrical pores with 0.31 and 0.54 
m in diameter through the reaction of the carboxylic acids on the surfaces with the alkylation reagent bearing a pyrene fluorophore. The incorporation of the fluorophore on the pore internal surfaces were successfully confirmed by the fluorescence microscope images of the membrane reacting with the alkylation reagent bearing a pyrene fluorophore.
Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.
Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02
Times Cited Count：2 Percentile：6.49(Physics, Fluids & Plasmas)The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-
. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.
Maekawa, Yasunari; Suzuki, Yasuyuki; Yoshida, Masaru; Maeyama, Katsuya*; Yonezawa, Noriyuki*
Polymer, 44(8), p.2307 - 2312, 2003/04
Times Cited Count：7 Percentile：29.01(Polymer Science)The preparation of ion track membranes of thermally stable polyimide films has been performed by ion beam irradiation of partially imidized polyamic acid (PAA) films followed by alkaline etching and final imidization. No discernible positive hole patterns were observed on the irradiated films of partially imidized PAA containing sulfonyl linkages, although sulfonyl group is known to be highly sensitive to ion beams. In contrast, positive hole patterns appeared on the irradiated films of the partially imidized PAA with 68-89% imidization degrees that contains sulfonyl linkages along with a methylene group in the main chain. The most contrasty hole patterns with 0.3 m diameter were observed on the irradiated PAA films of 89% imidization degree. The irradiated PAA film with the hole patterns was then transformed to the corresponding polyimide film with curing at 350
C for 1 h. From the structural comparison of the polyimides, the possible mechanism for the hole pattern formation is suggested.
Suzuki, Yasuyuki; Maekawa, Yasunari; Yoshida, Masaru; Maeyama, Katsuya*; Yonezawa, Noriyuki*
Chemistry of Materials, 14(10), p.4186 - 4191, 2002/10
Times Cited Count：17 Percentile：53.64(Chemistry, Physical)Dual tone imaging of polyimide films was prepared by Xe ion beam irradiation of partially imidized polyamic acid (PAA) films followed by alkaline etching in aqueous tetramethylammonium hydroxide solution and heating of treated films. In 87% imidized PAA film, ion beam irradiation produced a negative hemispheric structured image with 1.0 mm height and 1.5 mm diameter. In contrast, a positive hole pattern with 0.3 mm diameter appeared on the 82% imidized PAA film. Positive and negative images were considered to be switched by slight change in the balance of scission and crosslinking of the polymer chains, resulting from energy deposition of the ion beam.
Suzuki, Yasuyuki*; Li, J.; Maekawa, Yasunari; Yoshida, Masaru; Maeyama, Katsuya*; Yonezawa, Noriyuki*
Nihon Kagakkai-Shi, 2002(2), p.255 - 259, 2002/02
The hydrophilic surface of poly(ethylene terephthalate) (PET) film, obtained by partial hydrolysis, was converted to hydrophobic one under dry air, saturated water vapor atmosphere, nitrogen, and vacuum at temperatures ranging from 0 to 80C. The hydrophilicity of the surface increased significantly faster under the saturated water vapor although it was the most hydrophilic in the examined conditions. From the dependence of the absolute temperature on the rate of hydrophilicity change for each storage condition, a discontinuous point at ca. 50C was observable only under the water vapor condition. This relation indicates that the appreciable acceleration of the hydrophilicity change on the surface under the hydrophilic condition might be resulted from the increase of the surface mobility due to the water adsorption on the PET surface.
Goto, Shunji*; Takeshita, Kunikazu*; Suzuki, Yoshio*; Ohashi, Haruhiko*; Asano, Yoshihiro; Kimura, Hiroaki*; Matsushita, Tomohiro*; Yagi, Naoto*; Isshiki, M.*; Yamazaki, H.*; et al.
Nuclear Instruments and Methods in Physics Research A, 467-468(Part1), p.682 - 685, 2001/07
no abstracts in English
*; *; *; ; Kikuchi, Yasuyuki
JAERI-M 86-004, 91 Pages, 1986/02
no abstracts in English
Cr; ; Motoki, Ryozo; Yamamoto, Takeo; Nishida, Hiroshi*; Shin, Sumio*; Sato, Kiichi*; *
Radioisotopes, 34(3), p.144 - 150, 1985/00
no abstracts in English
CrShin, Sumio*; ; *; Nishida, Hiroshi*; ; ; Motoki, Ryozo
Igaku No Ayumi, 130(6-7), p.437 - 439, 1984/00
no abstracts in English
Kikuchi, Yasuyuki; Katsuragi, Satoru; *;
JAERI 1239, 63 Pages, 1975/08
no abstracts in English
-xylene diamine-6 by ion-beam-induced graft polymerizationSuzuki, Yasuyuki; Yamaki, Tetsuya; Asano, Masaharu; Yoshida, Masaru
no journal, ,
We prepared polymer electrolyte membranes by the ion-beam-induced graft polymerization of sodium 
-styrenesulfonate (SSS) into nylon -xylene diamine-6 (NMXD6) films. The grafting yield was controlled by adjusting the grafting conditions such as reaction times, temperatures, ion species and fluences of the pre-irradiated ions. The membranes prepared at 50 and 60C exhibited homogeneous distribution of sulfonic acid groups across their transverse plane. The proton conductivity of the wet membranes at room temperature ranged from 0.0021 to 0.054 S/cm in the direction of thickness, depending on their ion exchange capacity.
