Chemical-pressure-induced point defects enable low thermal conductivity for MgSn and MgSi single crystals

Saito, Wataru*; Hayashi, Kei*; Huang, Z.*; Sugimoto, Kazuya*; Oyama, Kenji*; Happo, Naohisa*; Harada, Masahide; Oikawa, Kenichi; Inamura, Yasuhiro; Hayashi, Koichi*; et al.

ACS Applied Energy Materials (Internet), 4(5), p.5123 - 5131, 2021/05

https://doi.org/10.1021/acsaem.1c00670

Segmental motions of proteins under non-native states evaluated using quasielastic neutron scattering

Fujiwara, Satoru*; Matsuo, Tatsuhito*; Sugimoto, Yasunobu*; Shibata, Kaoru

Journal of Physical Chemistry Letters (Internet), 10(23), p.7505 - 7509, 2019/12

https://doi.org/10.1021/acs.jpclett.9b03196

Characterization of the dynamics of disordered polypeptide chains is required to elucidate the behavior of intrinsically disordered proteins and proteins under non-native states related to the folding process. Here we develop a method using quasielastic neutron scattering, combined with small-angle X-ray scattering and dynamic light scattering, to evaluate segmental motions of proteins as well as diffusion of the entire molecules and local side-chain motions. We apply this method to RNase A under the unfolded and molten-globule (MG) states. The diffusion coefficients arising from the segmental motions are evaluated and found to be different between the unfolded and MG states. The values obtained here are consistent with those obtained using the fluorescence-based techniques. These results demonstrate not only feasibility of this method but also usefulness to characterize the behavior of proteins under various disordered states.

Size and dopant-concentration dependence of photoluminescence properties of ion-implanted phosphorus- and boron-codoped Si nanocrystals

Nakamura, Toshihiro*; Adachi, Sadao*; Fujii, Minoru*; Sugimoto, Hiroshi*; Miura, Kenta*; Yamamoto, Shunya

Physical Review B, 91(16), p.165424_1 - 165424_8, 2015/04

https://doi.org/10.1103/PhysRevB.91.165424

Semiconductor nanocrystals have unique electrical and optical properties, because of the quantum confinement effect, and the doping of impurities into nanocrystals. In this study, we investigated the photoluminescence (PL) properties of phosphorus- (P) and boron- (B) co-doped Si nanocrystals (Si NCs), which was synthesized using an ion implantation technique. The Si-NC size (average diameter: 3.5, 4.4, 5.2 nm) and the P and B ion doses (0.1-4.510 cm)values were systematically varied. We find that the PL peak energy shifts to lower values with increasing the average diameters of Si NCs and PB ion dose. The results of PL measurements indicate that the PL spectra are due to the band-to-band transition at the reduced Si-NC band gap caused by the formation of impurity and the radiative transitions between defect- and/or impurity-related localized states. It was found that the PL properties can be controlled by varying the Si-NC size as well as the dopant concentration.

From laboratory to field; -knockdown rice is a promising candidate for Cd phytoremediation in paddy fields

Takahashi, Ryuichi*; Ishimaru, Yasuhiro*; Shimo, H.*; Bashir, K.*; Senoura, Takeshi*; Sugimoto, Kazuhiko*; Ono, Kazuko*; Suzui, Nobuo; Kawachi, Naoki; Ishii, Satomi; et al.

PLOS ONE (Internet), 9(6), p.e98816_1 - e98816_7, 2014/06

https://doi.org/10.1371/journal.pone.0098816

Activation analyses of air in the accelerator vault of LIPAc building by deuteron beam at 5 MeV and 9 MeV

Takahashi, Hiroki; Maebara, Sunao; Sakaki, Hironao; Suzuki, Hiromitsu; Sugimoto, Masayoshi

JAEA-Conf 2013-002, p.109 - 112, 2013/10

https://doi.org/10.11484/jaea-conf-2013-002

Neutron diffraction measurements of skeletal muscle using the contrast variation technique; Analysis of the equatorial diffraction patterns

Fujiwara, Satoru; Takezawa, Yasunori*; Sugimoto, Yasunobu*; Wakabayashi, Katsuzo*

Journal of Structural Biology, 167(1), p.25 - 35, 2009/07

https://doi.org/10.1016/j.jsb.2009.03.018

In neutron scattering and diffraction, information on variations of scattering length density of molecules of interest can be extracted by the contrast variation technique. In order to explore the possibilities of this contrast variation technique in neutron fiber diffraction, neutron diffraction measurements of skeletal muscles were performed. The neutron fiber diffraction patterns of frog sartorius muscles were measured in the relaxed state and the rigor state, in various DO concentrations. It was shown that there were variations in the scattering length density of the protein regions in the unit cell of the muscle structure. Analysis of the equatorial reflections showed that the phase information of these reflections is obtained, that the scattering length density is different between the thick filament region and the thin filament region, and that the density of the thick filament changes as the state of muscle changes from the relaxed state to the rigor state.

Current status of the control system for J-PARC accelerator complex

Yoshikawa, Hiroshi; Sakaki, Hironao; Sako, Hiroyuki; Takahashi, Hiroki; Shen, G.; Kato, Yuko; Ito, Yuichi; Ikeda, Hiroshi*; Ishiyama, Tatsuya*; Tsuchiya, Hitoshi*; et al.

Proceedings of International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS '07) (CD-ROM), p.62 - 64, 2007/10

J-PARC is a large scale facility of the proton accelerators for the multi-purpose of scientific researches in Japan. This facility consists of three accelerators and three experimental stations. Now, J-PARC is under construction, and LINAC is operated for one year, 3GeV synchrotron has just started the commissioning in this October the 1st. The completion of this facility will be next summer. The control system of accelerators established fundamental performance for the initial commissioning. The most important requirement to the control system of this facility is to minimize the activation of accelerator devices. In this paper, we show that the performances of each layer of this control system have been achieved in the initial stage.

J-PARC 3GeV RCS control system

Takahashi, Hiroki; Kawase, Masato; Sakaki, Hironao; Yoshikawa, Hiroshi; Ishiyama, Tatsuya*; Ito, Yuichi; Kato, Yuko; Sugimoto, Makoto*; Suzuki, Takahiro*

Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.442 - 444, 2006/08

no abstracts in English

RDB system in J-PARC LINAC and its application to commissioning, 2

Sako, Hiroyuki; Sakaki, Hironao; Takahashi, Hiroki; Yoshikawa, Hiroshi; Ito, Yuichi; Kato, Yuko; Kawase, Masato; Shen, G.; Kiyomichi, Akio; Kamikubota, Norihiko*; et al.

Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.373 - 375, 2006/00

A Relational database (RDB) system, which is the core of the J-PARC Linac control system, has been developed. The beam commissioning of Linac is planned to start in December 2006. The RDB sytem consists of the following databases; "DB1", which records basic device parameters, "DB2", which acquires online EPICS data, "Operation Log DB", which records a history of operating parameters, and "Commissioning DB", which holds information on geometry of devices and commissioning. We report on the development status of each DB as well as status of the unified commissioning environment software which utilizes these databases.

RDB system in J-PARC LINAC and its application to commissioning

Sako, Hiroyuki; Sakaki, Hironao; Takahashi, Hiroki; Yoshikawa, Hiroshi; Ito, Yuichi*; Kato, Yuko*; Kamikubota, Norihiko*; Sugimoto, Makoto*; Watanabe, Kazuhiko*; Ikeda, Hiroshi*; et al.

Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.462 - 464, 2005/07

Current status of the RDB system in J-PARC LINAC is presented. The machine database records static data of devices and the control system, whereas the operation log database records a history of operation parameters. The overall design of control flow among high-level applications, simulators, and database is described. Then results of a control test of the power supply for DTQ, and a prototype test of the operation log database in MEBT1 test bench at KEK are reported. In the end, a scheme to generate simulation configuration files from RDB is shown.