Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 28

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Differences in water dynamics between the hydrated chitin and hydrated chitosan determined by quasi-elastic neutron scattering

Hirota, Yuki*; Tominaga, Taiki*; Kawabata, Takashi*; Kawakita, Yukinobu; Matsuo, Yasumitsu*

Bioengineering (Internet), 10(5), p.622_1 - 622_17, 2023/05

 Times Cited Count:0 Percentile:0.01(Biotechnology & Applied Microbiology)

Journal Articles

Quasielastic neutron scattering probing H$$^{-}$$ dynamics in the H$$^{-}$$ conductors LaH$$_{3-2x}$$O$$_{x}$$

Tamatsukuri, Hiromu; Fukui, Keiga*; Iimura, Soshi*; Honda, Takashi*; Tada, Tomofumi*; Murakami, Yoichi*; Yamaura, Junichi*; Kuramoto, Yoshio*; Sagayama, Hajime*; Yamada, Takeshi*; et al.

Physical Review B, 107(18), p.184114_1 - 184114_8, 2023/05

 Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)

Journal Articles

Short-range spin order in paramagnetic AgCrSe$$_{2}$$

Nakamura, Jumpei*; Kawakita, Yukinobu; Okabe, Hirotaka*; Li, B.*; Shimomura, Koichiro*; Suemasu, Takashi*

Journal of Physics and Chemistry of Solids, 175, p.111199_1 - 111199_8, 2023/04

 Times Cited Count:1 Percentile:14.38(Chemistry, Multidisciplinary)

Journal Articles

Hydrogen dynamics in hydrated chitosan by quasi-elastic neutron scattering

Hirota, Yuki*; Tominaga, Taiki*; Kawabata, Takashi*; Kawakita, Yukinobu; Matsuo, Yasumitsu*

Bioengineering (Internet), 9(10), p.599_1 - 599_17, 2022/10

 Times Cited Count:2 Percentile:32.07(Biotechnology & Applied Microbiology)

Journal Articles

Revealing the ion dynamics in Li$$_{10}$$GeP$$_{2}$$S$$_{12}$$ by quasi-elastic neutron scattering measurements

Hori, Satoshi*; Kanno, Ryoji*; Kwon, O.*; Kato, Yuki*; Yamada, Takeshi*; Matsuura, Masato*; Yonemura, Masao*; Kamiyama, Takashi*; Shibata, Kaoru; Kawakita, Yukinobu

Journal of Physical Chemistry C, 126(22), p.9518 - 9527, 2022/06

 Times Cited Count:6 Percentile:56.94(Chemistry, Physical)

Journal Articles

Hydrogen impurities in p-type semiconductors, GeS and GeTe

Nakamura, Jumpei*; Kawakita, Yukinobu; Shimomura, Koichiro*; Suemasu, Takashi*

Journal of Applied Physics, 130(19), p.195701_1 - 195701_7, 2021/11

 Times Cited Count:2 Percentile:7.45(Physics, Applied)

Journal Articles

Dynamics of proteins with different molecular structures under solution condition

Inoue, Rintaro*; Oda, Takashi*; Nakagawa, Hiroshi; Tominaga, Taiki*; Saio, Tomohide*; Kawakita, Yukinobu; Shimizu, Masahiro*; Okuda, Aya*; Morishima, Ken*; Sato, Nobuhiro*; et al.

Scientific Reports (Internet), 10, p.21678_1 - 21678_10, 2020/12

 Times Cited Count:3 Percentile:12.97(Multidisciplinary Sciences)

Incoherent quasielastic neutron scattering (iQENS) is a fascinating technique for investigating the internal dynamics of protein. However, both low flux of neutron beam and absence of analytical procedure for extracting the internal dynamics from iQENS profile have been obstacles for studying it under physiological condition (in solution). Thanks to the recent development of neutron source, spectrometer and computational technique, they enable us to decouple internal dynamics, translational and rotational diffusions from the iQENS profile. The internal dynamics of two proteins: globular domain protein (GDP) and intrinsically disordered protein (IDP) in solution were studied. It was found that the average relaxation rate of IDP was larger than that of GDP. Through the detailed analyses on their internal dynamics, it was revealed that the fraction of mobile H atoms in IDP was much higher than that in GDP. Interestingly, the fraction of mobile H atoms was closely related to the fraction of H atoms on highly solvent exposed surfaces. The iQENS study presented that the internal dynamics were governed by the highly solvent exposed amino acid residues depending upon protein molecular architectures.

Journal Articles

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.

Journal Articles

Colossal negative thermal expansion induced by magnetic phase competition on frustrated lattices in Laves phase compound (Hf,Ta)Fe$$_2$$

Li, B.; Luo, X. H.*; Wang, H.*; Ren, W. J.*; Yano, S.*; Wang, C.-W.*; Gardner, J. S.*; Liss, K.-D.*; Miao, P.*; Lee, S.-H.*; et al.

Physical Review B, 93(22), p.224405_1 - 224405_6, 2016/06

 Times Cited Count:45 Percentile:85.71(Materials Science, Multidisciplinary)

Journal Articles

None

Ishikawa, Makoto; Hayashi, Hideyuki*; Kamei, Takanobu*; Sanda, Toshio*; Kawakita, Takashi*

Donen Giho, (77), p.92 - 96, 1991/03

None

Oral presentation

Present status of the computing environment for the experimental instruments in J-PARC/MLF

Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi; Ohara, Takashi; Otomo, Toshiya*; Suzuki, Jiro*; Muto, Suguru*; Kojima, Kenji*; Kawakita, Yukinobu

no journal, , 

Oral presentation

Current status of sample environment in MLF, J-PARC

Kawamura, Seiko; Yokoo, Tetsuya*; Kambara, Wataru; Inamura, Yasuhiro; Nakatani, Takeshi; Torii, Shuki*; Kajimoto, Ryoichi; Nakajima, Kenji; Kaneko, Koji; Kawakita, Yukinobu; et al.

no journal, , 

Materials and Life Science Experimental Facility at J-PARC started the user program in December 2008. Various neutron experiments are currently performed there in wide range of scientific researches and industrial applications. Standardization of sample environment (SE) equipments is one of the most important things at the beginning stage. Especially in our country, it often happens that each instrument carries and operates SE devices independently. This situation results in an excess of the cost and incompatibility among the instruments unless we have any guidelines. Thus the SE team has discussed the SE-protocol, in which flange size, thermometers, controllers etc. are standardized. This should bring about saving the cost and manpower and increasing compatibility. The SE team is now discussing user support system in SE, preparation of the SE area, and so on. The technical staff members started working on practical things such as cooling test of cryostats.

Oral presentation

Present status of the MLF computing environment

Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi; Ohara, Takashi; Kawakita, Yukinobu; Otomo, Toshiya*; Suzuki, Jiro*; Muto, Suguru*; Kojima, Kenji*

no journal, , 

no abstracts in English

Oral presentation

Present status of the software framework "IROHA" in J-PARC/MLF computing environment

Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi; Ohara, Takashi; Kawakita, Yukinobu; Otomo, Toshiya*; Suzuki, Jiro*; Muto, Suguru*; Kojima, Kenji*; Clarke, M.*

no journal, , 

In this year, we are developing the following three items in the software framework "IROHA" which is the standard software for J-PARC/MLF computing environment. First, the experimental metadata are managed by the MLF database, which is available for the multi-dimensional data analysis environment. Second, the automatic experimental software is called "Experiment Scheduler", which is collaborated with ISIS. And third, the digital and analog signals are acquired as general event with "TRIGNET" which is the event recording system for the variation of the external fields. We present the detail of these items and the remote data analysis environment which we will introduce next year.

Oral presentation

Current status and future plan of sample environment in MLF, J-PARC

Kawamura, Seiko; Yokoo, Tetsuya*; Kambara, Wataru; Munakata, Koji*; Kajimoto, Ryoichi*; Nakatani, Takeshi; Kaneko, Koji; Kawakita, Yukinobu; Takata, Shinichi; Nakajima, Kenji; et al.

no journal, , 

In large user facilities such as neutron experimental facilities, sample environment (SE) is one of the most important factors to yield high-quality output. In the Materials and Life Science Experimental Facility (MLF) in J-PARC, various neutron experiments have been performed in wide range of scientific researches and industrial applications, and the number and variety of proposals will further increase after resuming operation of J-PARC. At the beginning stage, the SE team in MLF has discussed SE standardization, to save the cost and manpower, to make compatibility among instruments, and to increase the experimental efficiency by sharing the SE devices and techniques for operation. Recently we started preparation of "SE area" in the experimental hall, where we can do maintenance of equipments, pre-cooling of cryostats and so on. The SE team is now discussing future plan including user support system.

Oral presentation

Structural study of solid solution of protonic conductors Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$ by single crystal neutron diffraction

Kiyanagi, Ryoji; Matsuo, Yasumitsu*; Ohara, Takashi; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Hanashima, Takayasu*; Munakata, Koji*; Nakao, Akiko*; et al.

no journal, , 

The materials represented as M$$_{3}$$H(XO$$_{4}$$)$$_{2}$$ is known to exhibit a super protonic conductivity at rather low temperature. The protonic conductivity emerges upon a structural phase transition, and the phase transition temperature varies depending on the elements at M and X. In addition, the protonic conductivity also varies depending on the elements, but the origin has not been uncovered. In order to clarify the relation between the structure and the protonic conductivity including the phase transition mechanism, Solid solutions of super protonic conductors, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$ (x=0, 1, 2, 3), were structurally investigated by single crystal neutron diffraction. The structure analyses showed evident linear relation between the lattice parameters and x. Meanwhile, K was found to preferably reside at one of the two M sites. A apparent relation between the occupancy of K at one site and the transition temperature and the hydrogen-bond length were demonstrated.

Oral presentation

Structure analysis and phase transition of super protonic conductor Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$

Kiyanagi, Ryoji; Matsuo, Yasumitsu*; Ohara, Takashi; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; et al.

no journal, , 

The materials represented as M$$_{3}$$H(XO$$_{4}$$)$$_{2}$$ are known to exhibit super protonic conductivity at rather low temperature, but the mechanism of the super protonic phase transition and the protonic conduction have not been clarified. In this study, a mixed material, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$, was investigated by means of conductivity measurements and neutron diffraction. The neutron diffraction experiments were conducted on BL18 at J-PARC/MLF. The conductivity measurements revealed that the phase transition temperature significantly changes below x=2. Meanwhile, the neutron structure analyses revealed that K atoms exclusively occupy one of two non-equivalent sites for M atoms below x=2. These observations are indicative of the close relationship between the phase transition and the internal atomic arrangement.

Oral presentation

Relation between crystal structure and phase transition of superprotonic conductor, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$

Kiyanagi, Ryoji; Matsuo, Yasumitsu*; Ohara, Takashi; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Hanashima, Takayasu*; Munakata, Koji*; Nakao, Akiko*; et al.

no journal, , 

M$$_{3}$$H(SeO$$_{4}$$)$$_{2}$$ forms a material group that exhibits superprotonic conductivity at rather low temperature. The superprotonic conductivity manifests itself upon a structural phase transition. The phase transition temperature varies depending on the elements of M and X. In order to clarify the relation between the crystal structure and the phase transition, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$ was investigated by means of a conductivity measurement and single crystal neutron structure analyses. The phase transition temperature was found to be non-linear to the variation of x by the conductivity measurement. The structure analyses revealed that the site occupancy of K at one of two M sites non-linearly varied with respect to x. This suggest that a close relation between the M site and the superprotonic phase transition.

Oral presentation

Phase transition and internal crystal structure of superprotonic conductor, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$

Kiyanagi, Ryoji; Matsuo, Yasumitsu*; Ohara, Takashi; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Hanashima, Takayasu*; Munakata, Koji*; Nakao, Akiko*; et al.

no journal, , 

The materials, M$$_{3}$$H(XO$$_{4}$$)$$_{2}$$ (M=alkaline metal, X=Se, S), exhibit high protonic conductivities in a relatively low temperature region. The high protonic conductivities emerge upon a structural phase transition and the phase transition temperature (Tc) varies depending on the elements of M and X. In this study, mixed materials, Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$, were studied by means of conductivity measurements and single crystal neutron structure analyses in order to clarify how the elements at the M site affect the Tc from the structural aspect. The conductivity measurements revealed that the Tc decreased as the K content increased. The variation of the Tc was found to be non-linear with respect to the K content. The structure analyses showed that the K ions preferred to occupy one of two M sites and the occupancy of the K ion at this site non-linearly varied. In addition, the SeO$$_{4}$$ tetrahedron became more distorted as the K content increased, suggesting the close relationship between the distortion and the Tc.

Oral presentation

Proton conduction mechanism and phase transition of (Rb,K)$$_{3}$$H(SeO$$_{4}$$)$$_{2}$$

Kiyanagi, Ryoji; Matsuo, Yasumitsu*; Ishikawa, Yoshihisa*; Noda, Yukio*; Ohara, Takashi; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Hanashima, Takayasu*; et al.

no journal, , 

The materials represented as M$$_{3}$$H(XO$$_{4}$$)$$_{2}$$ (M=alkali metals, X=Se, S) are known to exhibit high protonic conductivities at relatively low temperature. Although the high protonic conductivity is considered to be due to the disorder of the hydrogen bonds in the materials, details have not been well understood. In addition, clarification of the phase transition to the high proton conducting phase is important in order to understand the realization of the high protonic conductivity. In this study, a high temperature neutron structural study was carried out on Rb$$_{3}$$H(SeO$$_{4}$$)$$_{2}$$, and the solid solution of Rb$$_{3-x}$$K$$_{x}$$H(SeO$$_{4}$$)$$_{2}$$ were also investigated by means of conductivity measurements and neutron structural studies. The high temperature neutron structure analyses revealed that the protons in the high proton conducting phase were two dimensionally distributed, which is considered to be the direct observation of the conducting protons. The solid solution exhibited non-linear decreases of the phase transition temperatures as the K concentration increased. The K ions were found to prefer to occupy one of two possible sites, of which occupancies apparently have close relationship with the phase transition temperature.

28 (Records 1-20 displayed on this page)