JOPSS - Search Results

Wu, P.*; Fan, F.-R.*; Hagihara, Masato*; Kofu, Maiko; Peng, K.*; Ishikawa, Yoshihisa*; Lee, S.*; Honda, Takashi*; Yonemura, Masao*; Ikeda, Kazutaka*; et al.

New Journal of Physics (Internet), 22(8), p.083083_1 - 083083_9, 2020/08

https://doi.org/10.1088/1367-2630/aba98f

Times Cited Count：8 Percentile：58.58(Physics, Multidisciplinary)

Thermoelectric material SnSe has aroused world-wide interests in the past years, and its inherent strong lattice anharmonicity is regarded as a crucial factor for its outstanding thermoelectric performance. However, the understanding of lattice anharmonicity in SnSe system remains inadequate, especially regarding how phonon dynamics are affected by this behavior. In this work, we present a comprehensive study of lattice dynamics on Na $_{0.003}$ Sn $_{0.997}$ Se $_{0.9}$ S $_{0.1}$ by means of neutron total scattering, inelastic neutron scattering, Raman spectroscopy as well as frozen-phonon calculations. Lattice anharmonicity is evidenced by pair distribution function, inelastic neutron scattering and Raman measurements. By separating the effects of thermal expansion and multi-phonon scattering, we found that the latter is very significant in high-energy optical phonon modes. The strong temperature-dependence of these phonon modes indicate the anharmonicity in this system. Moreover, our data reveals that the linewidths of high-energy optical phonons become broadened with mild doping of sulfur. Our studies suggest that the thermoelectric performance of SnSe could be further enhanced by reducing the contributions of high-energy optical phonon modes to the lattice thermal conductivity via phonon engineering.

Journal Articles

Shell structure of the neutron-rich isotopes $^{69,71,73}$ Co

Lokotko, T.*; Leblond, S.*; Lee, J.*; Doornenbal, P.*; Obertelli, A.*; Poves, A.*; Nowacki, F.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Authelet, G.*; et al.

Physical Review C, 101(3), p.034314_1 - 034314_7, 2020/03

https://doi.org/10.1103/PhysRevC.101.034314

Times Cited Count：10 Percentile：69.78(Physics, Nuclear)

The structures of the neutron-rich $^{69,71,73}$ Co isotopes were investigated via () knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Level schemes were reconstructed using the coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations suggests coexistence of spherical and deformed shapes at low excitation energies in the $^{69,71,73}$ Co isotopes.

Journal Articles

Experimental determination of the emissivity of nuclear graphite at high temperature conditions

Chai, P.; Wu, Y.*; Okamoto, Koji

Mechanical Engineering Letters (Internet), 6, p.20-00204_1 - 20-00204_7, 2020/00

https://doi.org/10.1299/mel.20-00204

In a High-Temperature Gas-cooled Reactor (HTGR), radiation is the dominant form of heat transfer due to the high temperature environment. Therefore, the emissivity of the core materials (mainly nuclear grade graphite) is important for reactor safety assessment. In this paper, the emissivity of nuclear grade graphite IG-110 was measured in the temperature range from 500 $^{circ}$ C to 1000 $^{circ}$ C by using an infrared thermometer. Besides, the impact of the graphite oxidation, which may take place in a postulated air ingress accident, was also evaluated. As a result, it was found that the emissivity of IG-110 grade graphite decreases slightly as the temperature increase. Moreover, a relatively high emissivity was detected in the pre-oxidized specimen. Based on the measurement data, two experimental correlations were suggested for the engineering applications. It could also be concluded that the commonly used value of the graphite emissivity (0.8), is conservative for engineering judgment.

Journal Articles

Nuclear structure of $^{76}$ Ni from the (,) reaction

Elekes, Z.*; Kripk, *; Sohler, D.*; Sieja, K.*; Ogata, Kazuyuki*; Yoshida, Kazuki; Doornenbal, P.*; Obertelli, A.*; Authelet, G.*; Baba, Hidetada*; et al.

Physical Review C, 99(1), p.014312_1 - 014312_7, 2019/01

https://doi.org/10.1103/PhysRevC.99.014312

Times Cited Count：10 Percentile：64.15(Physics, Nuclear)

The nuclear structure of the $^{76}$ Ni nucleus was investigated by (,) reaction using a NaI(Tl) array to detect the deexciting prompt rays. A new transition with an energy of 2227 keV was identified by and coincidences. Our shell-model calculations using the Lenzi, Nowacki, Poves, and Sieja interaction produced good candidates for the experimental proton hole states in the observed energy region, and the theoretical cross sections showed good agreement with the experimental values. Although we could not assign all the experimental states to the theoretical ones unambiguously, the results are consistent with a reasonably large Z = 28 shell gap for nickel isotopes in accordance with previous studies.

Journal Articles

Investigation of the electronic structure and lattice dynamics of the thermoelectric material Na-doped SnSe

Wu, P.*; Zhang, B.*; Peng, K. L.*; Hagiwara, Masayuki*; Ishikawa, Yoshihisa*; Kofu, Maiko; Lee, S. H.*; Kumigashira, Hiroshi*; Hu, C. S.*; Qi, Z. M.*; et al.

Physical Review B, 98(9), p.094305_1 - 094305_7, 2018/09

https://doi.org/10.1103/PhysRevB.98.094305

Times Cited Count：11 Percentile：45.99(Materials Science, Multidisciplinary)

Using angle-resolved photoemission spectroscopy and inelastic neutron scattering, we have studied how electronic structures and lattice dynamics evolve with temperature in Na-doped SnSe.

Journal Articles

A Fluorometric skin-interfaced microfluidic device and smartphone imaging module for quantitative analysis of sweat chemistry

Sekine, Yurina; Kim, S. B.*; Zhang, Y.*; Bandodkar, A. J.*; Xu, S.*; Choi, J.*; Irie, Masahiro*; Ray, T. R.*; Kohli, P.*; Kozai, Naofumi; et al.

Lab on a Chip, 18(15), p.2178 - 2186, 2018/08

http://doi.org/10.1039/c8lc00530c

The rich composition of solutes and metabolites in sweat and its relative ease of collection upon excretion from skin pores make this class of biofluid an attractive candidate for point of care analysis. Here, we present a complementary approach that exploits fluorometric sensing modalities integrated into a soft, skin-interfaced microfluidic system which, when paired with a simple smartphone-based imaging module, allows for in-situ measurement of important biomarkers in sweat. A network array of microchannels and a collection of microreservoirs pre-filled with fluorescent probes that selectively react with target analytes in sweat (e.g. probes), enable quantitative, rapid analysis. Field studies on human subjects demonstrate the ability to measure the concentrations of chloride, sodium and zinc in sweat, with accuracy that matches that of conventional laboratory techniques.

Journal Articles

Atomically dispersed Pt on the surface of Ni particles; Synthesis and catalytic function in hydrogen generation from aqueous ammonia-borane

Li, Z.*; He, T.*; Matsumura, Daiju; Miao, S.*; Wu, A.*; Liu, L.*; Wu, G.*; Chen, P.*

ACS Catalysis, 7(10), p.6762 - 6769, 2017/10

https://doi.org/10.1021/acscatal.7b01790

Times Cited Count：158 Percentile：96.49(Chemistry, Physical)

Journal Articles

Shell evolution beyond =28 and =50; Spectroscopy of $^{81,82,83,84}$ Zn

Shand, C. M.*; Podolyk, Zs.*; Grska, M.*; Doornenbal, P.*; Obertelli, A.*; Nowacki, F.*; Otsuka, T.*; Sieja, K.*; Tostevin, J. A.*; Tsunoda, T.*; et al.

Physics Letters B, 773, p.492 - 497, 2017/10

https://doi.org/10.1016/j.physletb.2017.09.001

Times Cited Count：25 Percentile：87.36(Astronomy & Astrophysics)

Journal Articles

Observation of a -decaying millisecond isomeric state in $^{128}$ Cd $_{80}$

Jungclaus, A.*; Grawe, H.*; Nishimura, Shunji*; Doornenbal, P.*; Lorusso, G.*; Simpson, G. S.*; Sderstrm, P.-A.*; Sumikama, Toshiyuki*; Taprogge, J.*; Xu, Z. Y.*; et al.

Physics Letters B, 772, p.483 - 488, 2017/09

https://doi.org/10.1016/j.physletb.2017.07.006

Times Cited Count：8 Percentile：55.37(Astronomy & Astrophysics)

Journal Articles

Type II shell evolution in isobars from the island of inversion

Morales, A. I.*; Benzoni, G.*; Watanabe, H.*; Tsunoda, Yusuke*; Otsuka, T.*; Nishimura, Shunji*; Browne, F.*; Daido, R.*; Doornenbal, P.*; Fang, Y.*; et al.

Physics Letters B, 765, p.328 - 333, 2017/02

https://doi.org/10.1016/j.physletb.2016.12.025

Times Cited Count：34 Percentile：91.97(Astronomy & Astrophysics)