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Li, J.*; Li, X.*; Zhang, Y.*; Zhu, J.*; Zhao, E.*; Kofu, Maiko; Nakajima, Kenji; Avdeev, M.*; Liu, P.-F.*; Sui, J.*; et al.
Applied Physics Reviews (Internet), 11(1), p.011406_1 - 011406_8, 2024/03
Times Cited Count:0 Percentile:0.01(Physics, Applied)Shinohara, Yuya*; Iwashita, Takuya*; Nakanishi, Masahiro*; Osti, N. C.*; Kofu, Maiko; Nirei, Masami; Dmowski, W.*; Egami, Takeshi*
Journal of Physical Chemistry B, 128(6), p.1544 - 1549, 2024/02
Times Cited Count:0 Percentile:0.01(Chemistry, Physical)Kofu, Maiko; Kawamura, Seiko; Murai, Naoki; Ishii, Rieko*; Hirai, Daigoro*; Arima, Hiroshi*; Funakoshi, Kenichi*
Physical Review Research (Internet), 6(1), p.013006_1 - 013006_9, 2024/01
Ren, Q.*; Gupta, M. K.*; Jin, M.*; Ding, J.*; Wu, J.*; Chen, Z.*; Lin, S.*; Fabelo, O.*; Rodriguez-Velamazan, J. A.*; Kofu, Maiko; et al.
Nature Materials, 22, p.999 - 1006, 2023/05
Times Cited Count:21 Percentile:99.22(Chemistry, Physical)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)Masuda, Yuka*; Sakata, Shiomi*; Kayahara, Saori*; Irie, Natsumi*; Kofu, Maiko; Kono, Yohei*; Sakakibara, Toshiro*; Horii, Yoji*; Kajiwara, Takashi*
Journal of Physical Chemistry C, 127(6), p.3295 - 3306, 2023/02
Times Cited Count:1 Percentile:52.07(Chemistry, Physical)Wu, P.*; Murai, Naoki; Li, T.*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Kofu, Maiko; Nakajima, Kenji; Xia, K.*; Peng, K.*; Zhang, Y.*; et al.
New Journal of Physics (Internet), 25(1), p.013032_1 - 013032_11, 2023/01
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Sheng, J.*; Wang, L.*; Candini, A.*; Jiang, W.*; Huang, L.*; Xi, B.*; Zhao, J.*; Ge, H.*; Zhao, N.*; Fu, Y.*; et al.
Proceedings of the National Academy of Sciences of the United States of America, 119(51), p.e2211193119_1 - e2211193119_9, 2022/12
Times Cited Count:3 Percentile:28(Multidisciplinary Sciences)Soda, Minoru*; Kofu, Maiko; Kawamura, Seiko; Asai, Shinichiro*; Masuda, Takatsugu*; Yoshizawa, Hideki*; Furukawa, Hazuki*
Journal of the Physical Society of Japan, 91(9), p.094707_1 - 094707_5, 2022/09
Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)Tatsumi, Kazuyoshi; Inamura, Yasuhiro; Kofu, Maiko; Kiyanagi, Ryoji; Shimazaki, Hideaki*
Journal of Applied Crystallography, 55(3), p.533 - 543, 2022/06
Times Cited Count:0 Percentile:0.01(Chemistry, Multidisciplinary)A data-driven bin-width optimization for the histograms of measured data sets based on inhomogeneous Poisson processes was developed in a neurophysiology study [Shimazaki & Shinomoto (2007). Neural Comput. 19, 1503-1527], and a successive study [Muto et al. (2019). J. Phys. Soc. Jpn, 88, 044002] proposed its application to inelastic neutron scattering (INS) data. In the present study, the results of the method on experimental INS time-of-flight data collected under different measurement conditions from a copper single crystal are validated. The extrapolation of the statistics on a given data set to other data sets with different total counts precisely infers the optimal bin widths on the latter. The histograms with the optimized bin widths statistically verify two fine-spectral feature examples in the energy and momentum transfer cross sections: (i) the existence of the phonon band gaps; and (ii) the number of plural phonon branches located close to each other. This indicates that the applied method helps in the efficient and rigorous observation of spectral structures important in physics and materials science like novel forms of magnetic excitation and phonon states correlated to lattice thermal conductivities.
Luo, P.*; Zhai, Y.*; Falus, P.*; Garca Sakai, V.*; Hartl, M.*; Kofu, Maiko; Nakajima, Kenji; Faraone, A.*; Z, Y.*
Nature Communications (Internet), 13, p.2092_1 - 2092_9, 2022/04
Times Cited Count:3 Percentile:58.88(Multidisciplinary Sciences)Rathore, E.*; Juneja, R.*; Sarkar, D.*; Roychowdhury, S.*; Kofu, Maiko; Nakajima, Kenji; Singh, A. K.*; Biswas, K.*
Materials Today Energy (Internet), 24, p.100953_1 - 100953_9, 2022/03
Times Cited Count:14 Percentile:85.62(Chemistry, Physical)Okuma, Ryutaro*; Kofu, Maiko; Asai, Shinichiro*; Avdeev, M.*; Koda, Akihiro*; Okabe, Hirotaka*; Hiraishi, Masatoshi*; Takeshita, Soshi*; Kojima, Kenji*; Kadono, Ryosuke*; et al.
Nature Communications (Internet), 12, p.4382_1 - 4382_7, 2021/07
Times Cited Count:6 Percentile:61.42(Multidisciplinary Sciences)Kofu, Maiko; Watanuki, Ryuta*; Sakakibara, Toshiro*; Kawamura, Seiko; Nakajima, Kenji; Matsuura, Masato*; Ueki, Takeshi*; Akutsu, Kazuhiro*; Yamamuro, Osamu*
Scientific Reports (Internet), 11(1), p.12098_1 - 12098_8, 2021/06
Times Cited Count:5 Percentile:56.02(Multidisciplinary Sciences)Nakajima, Kenji; Kawamura, Seiko; Kofu, Maiko; Murai, Naoki; Inamura, Yasuhiro; Kikuchi, Tatsuya*; Wakai, Daisuke*
JPS Conference Proceedings (Internet), 33, p.011089_1 - 011089_7, 2021/03
The recent update of AMATERAS, a cold-neutron disk-chopper spectrometer at Japan Proton Accelerator Research Complex (J-PARC), is reported. AMATERAS has been operating for a decade. Since 2017, some updates have been done or are underway, which include installing new detectors, replacing the vacuum system of the scattering chamber, and other works. We are also working on the re-investigation of the resolution function. Demonstration measurements were carried out at 1MW test operations done in 2018 and 2019. Plans of upgrading the spectrometer are currently being considered.
Yamamoto, Naoki*; Kofu, Maiko; Nakajima, Kenji; Nakagawa, Hiroshi; Shibayama, Naoya*
Journal of Physical Chemistry Letters (Internet), 12(8), p.2172 - 2176, 2021/03
Times Cited Count:9 Percentile:68.98(Chemistry, Physical)Hydration water plays a crucial role for activating the protein dynamics required for functional expression. Yet, the details are not understood about how hydration water couples with protein dynamics. A temperature hysteresis of the ice formation of hydration water is a key phenomenon to understand which type of hydration water, unfreezable or freezable hydration water, is crucial for the activation of protein dynamics. Using neutron scattering, we observed a temperature-hysteresis phenomenon in the diffraction peaks of the ice of freezable hydration water, whereas protein dynamics did not show any temperature hysteresis. These results show that the protein dynamics is not coupled with freezable hydration water dynamics, and unfreezable hydration water is essential for the activation of protein dynamics.
Luo, P.*; Zhai, Y.*; Leao, J. B.*; Kofu, Maiko; Nakajima, Kenji; Faraone, A.*; Zhang, Y.*
Journal of Physical Chemistry Letters (Internet), 12(1), p.392 - 398, 2021/01
Times Cited Count:4 Percentile:27(Chemistry, Physical)Using neutron spin-echo spectroscopy, we studied the microscopic structural relaxation of a prototypical network ionic liquid ZnCl at the structure factor primary peak and prepeak. The results show that the relaxation at the primary peak is faster than the prepeak and that the activation energy is % higher. A stretched exponential relaxation is observed even at temperatures well-above the melting point . Surprisingly, the stretching exponent shows a rapid increase upon cooling, especially at the primary peak, where it changes from a stretched exponential to a simple exponential on approaching the . These results suggest that the appearance of glassy dynamics typical of the supercooled state even in the equilibrium liquid state of ZnCl as well as the difference of activation energy at the two investigated length scales are related to the formation of a network structure on cooling.
Zhang, D.*; Hu, X.*; Chen, T.*; Abernathy, D. L.*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Kofu, Maiko; Foley, B. J.*; Yoon, M.*; Choi, J. J.*; et al.
Physical Review B, 102(22), p.224310_1 - 224310_10, 2020/12
Times Cited Count:4 Percentile:26.53(Materials Science, Multidisciplinary)Nawa, Kazuhiro*; Hirai, Daigoro*; Kofu, Maiko; Nakajima, Kenji; Murasaki, Ryo*; Kogane, Satoshi*; Kimata, Motoi*; Nojiri, Hiroyuki*; Hiroi, Zenji*; Sato, Taku*
Physical Review Research (Internet), 2(4), p.043121_1 - 043121_11, 2020/12
The spin excitations of the = anisotropic triangular antiferromagnet CaReOCl were investigated by inelastic neutron-scattering experiments. The spin excitation spectrum exhibits sharp dispersive modes in addition to a spinonlike continuum. The consistency with the simulated spectrum based on the random-phase approximation is better for CaReOCl than for CsCuCl, indicating that the spin system in the former remains closer to a Tomonaga-Luttinger liquidlike disordered state.
Kojima, Seiji*; Novikov, V. N.*; Kofu, Maiko; Yamamuro, Osamu*
Physica Status Solidi (B), 257(11), p.200073_1 - 200073_6, 2020/11
Times Cited Count:3 Percentile:19.68(Physics, Condensed Matter)