Search

Your search keyword '"NAKAO, Aiko"' showing total 32 results
Start Over Author "NAKAO, Aiko" Search Limiters Full Text
32 results on '"NAKAO, Aiko"'

1. Influence of Perfluorinated Ionomer in PEDOT:PSS on the Rectification and Degradation of Organic Photovoltaic Cells

Author

Howells, Calvyn T., Saylan, Sueda, Kim, Haeri, Marbou, Khalid, Aoyama, Tetsua, Nakao, Aiko, Uchiyama, Masanobu, Samuel, Ifor D. W., Kim, Dong-Wook, Dahlem, Marcus S., and André, Pascal

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is widely used to build optoelectronic devices. However, as a hygroscopic water-based acidic material, it brings major concerns for stability and degradation, resulting in an intense effort to replace it in organic photovoltaic (OPV) devices. In this work, we focus on the perfluorinated ionomer (PFI) polymeric additive to PEDOT:PSS. We demonstrate that it can reduce the relative amplitude of OPV device burn-in, and find two distinct regimes of influence. At low concentrations there is a subtle effect on wetting and work function, for instance, with a detrimental impact on the device characteristics, and above a threshold it changes the electronic and device properties. The abrupt threshold in the conducting polymer occurs for PFI concentrations greater than or equal to the PSS concentration and was revealed by monitoring variations in transmission, topography, work-function, wettability and OPV device characteristics. Below this PFI concentration threshold, the power conversion efficiency (PCE) of OPVs based on poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) are impaired largely by low fill-factors due to poor charge extraction. Above the PFI concentration threshold, we recover the PCE before it is improved beyond the pristine PEDOT:PSS layer based OPV devices. Supplementary to the performance enhancement, PFI improves OPV device stability and lifetime. Our degradation study leads to the conclusion that PFI prevents water from diffusing to and from the hygrosopic PEDOT:PSS layer, which slows down the deterioration of the PEDOT:PSS layer and the aluminum electrode. These findings reveal mechanisms and opportunities that should be taken into consideration when developing components to inhibit OPV degradation., Comment: 14 pages, 9 figures, 1 table, Journal of Materials Chemistry A 2018

Published
2018
Full Text
View/download PDF

2. Origin of O2 Generation in Sulfide‐Based All‐Solid‐State Batteries and its Impact on High Energy Density.

Author

Yoshikawa, Keisuke, Kato, Takeshi, Suzuki, Yasuhiro, Shiota, Akihiro, Ohnishi, Tsuyoshi, Amezawa, Koji, Nakao, Aiko, Yajima, Takeshi, and Iriyama, Yasutoshi

Subjects
ELECTROCHEMICAL analysis, PHOTOELECTRON spectroscopy, ENERGY density, SOLID electrolytes, GAS analysis
Abstract

The cathode surface of sulfide‐based all‐solid‐state batteries (SBs) is commonly coated with amorphous‐LiNbO3 in order to stabilize charge–discharge reactions. However, high‐voltage charging diminishes the advantages, which is caused by problems with the amorphous‐LiNbO3 coating layer. This study has investigated the degradation of amorphous‐LiNbO3 coating layer directly during the high‐voltage charging of SBs. O2 generation via Li extraction from the amorphous‐LiNbO3 coating layer is observed using electrochemical gas analysis and electrochemical X‐ray photoelectron spectroscopy. This O2 leads to the formation of an oxidative solid electrolyte (SE) around the coating layer and degrades the battery performance. On the other hand, elemental substitution (i.e., amorphous‐LiNbxP1‐xO3) reduces O2 release, leading to stable high‐voltage charge–discharge reactions of SBs. The results have emphasized that the suppression of O2 generation is a key factor in improving the energy density of SBs. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

4. Epitaxially stabilized iridium spinel oxide without cations in the tetrahedral site

Author

Kuriyama, Hiromichi, Matsuno, Jobu, Niitaka, Seiji, Uchida, Masaya, Hashizume, Daisuke, Nakao, Aiko, Sugimoto, Kunihisa, Ohsumi, Hiroyuki, Takata, Masaki, and Takagi, Hidenori

Subjects
Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Materials Science
Abstract

Single-crystalline thin film of an iridium dioxide polymorph Ir2O4 has been fabricated by the pulsed laser deposition of LixIr2O4 precursor and the subsequent Li-deintercalation using soft chemistry. Ir2O4 crystallizes in a spinel (AB2O4) without A cations in the tetrahedral site, which is isostructural to lambda-MnO2. Ir ions form a pyrochlore sublattice, which is known to give rise to a strong geometrical frustration. This Ir spinel was found to be a narrow gap insulator, in remarkable contrast to the metallic ground state of rutile-type IrO2. We argue that an interplay of strong spin-orbit coupling and a Coulomb repulsion gives rise to an insulating ground state as in a layered perovskite Sr2IrO4., Comment: 9 pages, 3 figures

Published
2010
Full Text
View/download PDF

5. Metal-insulator Transition in a Pyrochlore-type Ruthenium oxide, Hg2Ru2O7

Author

Yamamoto, Ayako, Sharma, Peter A., Okamoto, Yoshihiko, Nakao, Aiko, Katori, Hiroko Aruga, Niitaka, Seiji, Hashizume, Daisuke, and Takagi, Hidenori

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

A new pyrochlore ruthenium oxide, Hg2Ru2O7 was synthesized under a high pressure of 6 GPa. In contrast to the extensively studied Ru4+ oxides, this compound possesses a novel Ru5+ valence state, corresponding to a half-filled t_2g_3 electron configuration. Hg2Ru2O7 exhibits a first order metal-insulator transition at 107 K, accompanied by a structural transition from cubic to lower symmetry. The behavior of the magnetic susceptibility suggests the possible formation of a spin singlet in the insulating low temperature state., Comment: 8 pages(text), 3 figures, and 1 page (references)

Published
2007
Full Text
View/download PDF

11. Autopsy of Patient with Severe Motor and Intellectual Disabilities who Died from Hemorrhagic Shock Due to Submucosal Dissection of the Esophagus

Author

Sakata, Kenji, Watanabe, Eri, Kubota, Kei, Sakaguchi, Takashi, Nakao, Aiko, Ide, Koj, Nakamura, Masatoshi, Hirose, Shinichi, and Ogawa, Atsushi

Subjects
食道粘膜剥離症, Submucosal dissection of the esophagus, Hemorrhagic shock, 重症心身障害児, 消化管出血, gastrointestinal hemorrhage, 出血性ショック, Child with severe motor and intellectual disabilities
Published
2019

14. Magnetic Scattering in Ni Wires Fabricated on Ferroelectric LiNbO3 Substrate for Magnetic Sensor Application

Author

Nakamura, Ryo, primary, Saegusa, Shunya, additional, Suzuki, Satoru, additional, Nakao, Aiko, additional, Utsumi, Yuichi, additional, Ohkochi, Takuo, additional, Oura, Masaki, additional, Takizawa, Yukako, additional, Saiki, Tsunemasa, additional, Lee, Taekhyeon, additional, Kim, Kab-Jin, additional, Yamada, Keisuke, additional, Ogasawara, Takeshi, additional, and Yamaguchi, Akinobu, additional

Published
2019
Full Text
View/download PDF

17. Focal Mechanisms and Regional Stress Field in the Northern Kinki District using the Dense Seismic Array

Author

AOKI, Hiroaki, KATAO, Hiroshi, IIO, Yoshihisa, MIURA, Tsutomu, NAKAO, Aiko, YONEDA, Itaru, SAWADA, Masayo, and NAKAO, Setsuro

Subjects
micro-earthquake, 発震機構, Tamba region, 微小地震, 丹波山地, focal mechanism, stress field, 応力場, 519.9
Abstract

2008年11月以降, 近畿地方北部に78点の臨時観測点を設置し，定常観測点を加えた150点のデータを解析した。同地域における一元化震源カタログの検知能力下限より大きい地震についてほぼ漏れなくメカニズム解を決定でき, 解析の空間・時間分解能が大幅に向上できることがわかった。丹波地域の応力逆解析結果には局地的な時間変化が見られるが，これは地震活動の偏りの影響であり，デクラスタ処理によりこれら「見かけ」の変化は除去される。逆に，M4級地震の余震などクラスター内部の詳細な解析が可能になった。琵琶湖西岸地域は逆断層型の応力場であるのに対して，丹波地域はσ2とσ3が分離できない場であり，両タイプの空間的境界は複雑な形状を呈する。丹波地域には小スケールの不均質構造が存在し，応力場推定に影響を与えていると考えられる。, In the northern Kinki district, we have done seismic observations using the dense seismic array stations since 2008. Total 150 temporal and permanent stations are used, and the average interval between the stations is about 5km. We get numerous mechanism data in a short time period, and the space and time resolution of the focal mechanism analyses are improved. Based on these data, we discuss about the feature of focal mechanisms, space and time variation of the regional stress field, and the detail mechanism distribution within aftershock sequence following the M4 class earthquakes.

Published
2012

18. Electronic structure of DNA nucleobases and their dinucleotides explored by soft X-ray spectroscopy

Author

Yoshihisa Harada, Takeuchi, Tomoyuki, Kino, Hiori, Fukushima, Akiko, Takakura, Kaoru, Hieda, Kotaro, Nakao, Aiko, Shin, Shik, and Fukuyama, Hidetoshi

Subjects
X-ray spectroscopy -- Analysis, Nucleotides -- Structure, Nucleotides -- Electric properties, Chemicals, plastics and rubber industries
Abstract

N 1s X-ray absorption, X-ray photoemission and resonant X-ray emission spectroscopy are used to investigate the electronic structures of a series of DNA nucleobases and their dinucleotides. Results indicate the guanine base and its nucleotide have a weak structure at the lowest binding energy and at this energy they isolate from the main valence band and form the highest occupied molecular orbital state.

Published
2006

19. Observation of Earthquakes for Crust and Upper Mantle Structures in the Kinki District, Japan

Author

NISHIMURA, Kazuhiro, TATSUMI, Kenichi, NAKAO, Setsuro, MIURA, Tsutomu, HIRANO, Norio, YAMAZAKI, Tomoya, FUKUSHIMA, Masayo, KAMO, Masato, MORI, Maiko, TOMISAKA, Kazuhide, YONEDA, Itaru, KAWAI, Kumiko, YOSHIDA, Yoshinori, HOSO, Yoshinobu, MATSUURA, Hideki, SHIBUTANI, Takuo, ITO, Kiyoshi, KATAO, Hiroshi, OHMI, Shiro, HIROSE, Issei, NAKAO, Aiko, and MORISHITA, Kanako

Subjects
携帯電話, 地下構造調査, 自然地震観測, earthquake observation, 519.9, seismic survey, mobile telephone, data communication, データ通信
Abstract

2002(平成14)年度から文部科学省の｢新世紀重点研究創生プラン～RR2000～｣の防災分野における都市再生プログラムとして，｢大都市大震災軽減化特別プロジェクト｣(大大特) が開始された。このプロジェクトのもと，京都大学防災研究所は近畿圏における地下構造調査を実施したが，制御震源による構造調査とともに，自然地震観測による調査も実施し，レシーバ関数解析結果と制御震源による構造を比較することで構造を精査した。そのため，近畿地方に35点の高感度臨時観測点を設置し，良好な記録を得た。また，周辺の高感度観測点を含めてデータの収録処理を行った。さらに，観測の効率化を目指して携帯電話を用いたデータ通信システムの開発を行った。, Underground structures in the Kinki district were surveyed from 2002 to 2006 under the Special Project for Earthquake Disaster Mitigation in Urban Areas. We carried out seismic observations with deploying 35 temporary stations across the Kinki district from the Pacific side to the Japan Sea side, in order to reveal subsurface structures, such as subducting Philippine Sea slab in southern Kinki and the continental Moho in northern Kinki. About 50, 000 event data were selected from continuously observed seismic records of both the temporary stations and nearby permanent stations during May, 2005 and Nov, 2006. We also try to develop a data communication system with a mobile telephone for a BREW application to improve the observation system.

Published
2007

20. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries

Author

Yabuuchi, Naoaki, primary, Nakayama, Masanobu, additional, Takeuchi, Mitsue, additional, Komaba, Shinichi, additional, Hashimoto, Yu, additional, Mukai, Takahiro, additional, Shiiba, Hiromasa, additional, Sato, Kei, additional, Kobayashi, Yuki, additional, Nakao, Aiko, additional, Yonemura, Masao, additional, Yamanaka, Keisuke, additional, Mitsuhara, Kei, additional, and Ohta, Toshiaki, additional

Published
2016
Full Text
View/download PDF

21. The 2000 Tottori-ken Seibu Earthquake - Seismic activity derived from the compilation of DPRI, JMA and Hi-net data

Author

OHMI, Shiro, WATANABE, Kunihiko, SHIBUTANI, Takuo, NAKAO, Setsuro, HIRANO, Norio, NAKAO, Aiko, TAKEUCHI, Haruko, TAKEUCHI, Fumiaki, MIWA, Sachie, SHITO, Azusa, KIM, Ai, and ENESCU, Bogdan

Subjects
The 2000 Tottori-ken Seibu Earrhquake, 地震活動, Routinely seismic network, 微小地震定常観測網, 平成12年鳥取県西部地震, Seismic activity, 453.3
Abstract

平成12年(2000年)10月6日13時30分頃, 鳥取県西部を震源とする気象庁マグニチュードMjma=7.3の地震が発生し, 気象庁により「平成12年鳥取県西部地震」と命名された。本報告では, 震源域とその周辺に展開された複数機関の微小地震観測網により収集されたデータをコンパイルした結果に基づき鳥取県西部地震の概要について報告する。, On October 6, 2000, an earthquake of Mjma=7.3 attacked western Tottori prefecture area, southwest Japan. This earthquake was named the 2000 Tottori-ken Seibu Earthquake by JMA. Micro seismic observation networks have been operated in this area by DPRI, JMA, and NIED, and thus many aftershocks data were obtained. In this paper, we will report the outline of the seismic activity of the 2000 Tottori-ken Seibu earthquake by compiling seismic data obtained by these seismic networks.

Published
2001

22. Synthesis of thin layer of fluorinated polymer by laser CVD. Direct synthesis of perfluoropolyether thin film on surface by oxidative polymerization of a perfluoropropene-oxygen mixture using an ArF excimer laser

Author

Tetsuro Majima, Abe Katsuo, Kyoko Sugita, Satoshi Matsunuma, and Nakao Aiko

Subjects
Materials science, Polymers and Plastics, Excimer laser, medicine.medical_treatment, Organic Chemistry, Thin layer, Layer by layer, Laser, Fluorinated polymer, law.invention, Chemical engineering, Polymerization, law, Materials Chemistry, medicine, Organic chemistry, Thin film, Oxygen mixture
Published
1993

25. 平成12年鳥取県西部地震-微小地震定常観測網による本震と余震活動

Author

OHMI, Shiro, WATANABE, Kunihiko, SHIBUTANI, Takuo, NAKAO, Setsuro, HIRANO, Norio, NAKAO, Aiko, TAKEUCHI, Haruko, TAKEUCHI, Fumiaki, MIWA, Sachie, SHITO, Azusa, KIM, Ai, ENESCU, Bogdan, 50263158, 70187417, 大見, 士朗, 渡辺, 邦彦, 澁谷, 拓郎, 中尾, 節郎, 平野, 憲雄, 中尾, 愛子, 竹内, 晴子, 竹内, 文朗, 三和, 佐知栄, 志藤, あずさ, 金, 亜伊, OHMI, Shiro, WATANABE, Kunihiko, SHIBUTANI, Takuo, NAKAO, Setsuro, HIRANO, Norio, NAKAO, Aiko, TAKEUCHI, Haruko, TAKEUCHI, Fumiaki, MIWA, Sachie, SHITO, Azusa, KIM, Ai, ENESCU, Bogdan, 50263158, 70187417, 大見, 士朗, 渡辺, 邦彦, 澁谷, 拓郎, 中尾, 節郎, 平野, 憲雄, 中尾, 愛子, 竹内, 晴子, 竹内, 文朗, 三和, 佐知栄, 志藤, あずさ, and 金, 亜伊

Abstract

平成12年(2000年)10月6日13時30分頃, 鳥取県西部を震源とする気象庁マグニチュードMjma=7.3の地震が発生し, 気象庁により「平成12年鳥取県西部地震」と命名された。本報告では, 震源域とその周辺に展開された複数機関の微小地震観測網により収集されたデータをコンパイルした結果に基づき鳥取県西部地震の概要について報告する。, On October 6, 2000, an earthquake of Mjma=7.3 attacked western Tottori prefecture area, southwest Japan. This earthquake was named the 2000 Tottori-ken Seibu Earthquake by JMA. Micro seismic observation networks have been operated in this area by DPRI, JMA, and NIED, and thus many aftershocks data were obtained. In this paper, we will report the outline of the seismic activity of the 2000 Tottori-ken Seibu earthquake by compiling seismic data obtained by these seismic networks., 平成12年(2000年)10月6日13時30分頃,鳥取県西部を震源とする気象庁マグニチュードMjma=7.3の地震が発生し,気象庁により「平成12年鳥取県西部地震」と命名された。本報告では,震源域とその周辺に展開された複数機関の微小地震観測網により収集されたデータをコンパイルした結果に基づき鳥取県西部地震の概要について報告する。

Published
2009

31. X-ray Photoemission Spectroscopy Study of Uniaxial Magnetic Anisotropy Induced in a Ni Layer Deposited on a LiNbO 3 Substrate.

Author

Yamaguchi, Akinobu, Ohkochi, Takuo, Oura, Masaki, Yamada, Keisuke, Saiki, Tsunemasa, Suzuki, Satoru, Utsumi, Yuichi, Nakao, Aiko, and Yarmoff, Jory

Subjects
MAGNETIC anisotropy, PHOTOELECTRON spectroscopy, X-ray spectroscopy, MAGNETIZATION reversal, MAGNETIC structure, MAGNETIC domain, MAGNETIC control
Abstract

The competition between magnetic shape anisotropy and the induced uniaxial magnetic anisotropy in the heterojunction between a ferromagnetic layer and a ferroelectric substrate serves to control magnetic domain structures as well as magnetization reversal characteristics. The uniaxial magnetic anisotropy, originating from the symmetry breaking effect in the heterojunction, plays a significant role in modifying the characteristics of magnetization dynamics. Magnetoelastic phenomena are known to generate uniaxial magnetic anisotropy; however, the interfacial electronic states that may contribute to the uniaxial magnetic anisotropy have not yet been adequately investigated. Here, we report experimental evidence concerning the binding energy change in the ferromagnetic layer/ferroelectric substrate heterojunction using X-ray photoemission spectroscopy. The binding energy shifts, corresponding to the chemical shifts, reveal the binding states near the interface. Our results shed light on the origin of the uniaxial magnetic anisotropy induced from the heterojunction. This knowledge can provide a means for the simultaneous control of magnetism, mechanics, and electronics in a nano/microsystem consisting of ferromagnetic/ferroelectric materials. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

32. Origin of O 2 Generation in Sulfide-Based All-Solid-State Batteries and its Impact on High Energy Density.

Author

Yoshikawa K, Kato T, Suzuki Y, Shiota A, Ohnishi T, Amezawa K, Nakao A, Yajima T, and Iriyama Y

Abstract

The cathode surface of sulfide-based all-solid-state batteries (SBs) is commonly coated with amorphous-LiNbO 3 in order to stabilize charge-discharge reactions. However, high-voltage charging diminishes the advantages, which is caused by problems with the amorphous-LiNbO 3 coating layer. This study has investigated the degradation of amorphous-LiNbO 3 coating layer directly during the high-voltage charging of SBs. O 2 generation via Li extraction from the amorphous-LiNbO 3 coating layer is observed using electrochemical gas analysis and electrochemical X-ray photoelectron spectroscopy. This O 2 leads to the formation of an oxidative solid electrolyte (SE) around the coating layer and degrades the battery performance. On the other hand, elemental substitution (i.e., amorphous-LiNb x P 1- x O 3 ) reduces O 2 release, leading to stable high-voltage charge-discharge reactions of SBs. The results have emphasized that the suppression of O 2 generation is a key factor in improving the energy density of SBs., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results