著者

Sugisaki Mitsuru Ren Hong-Wen Nair Selvakumar V. Nishi Kenichi Masumoto Yasuaki

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.66, no.23, pp.235309, 2002-12

被引用文献数

56 47

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The effects of external electric and magnetic fields on InP self-assembled quantum dots (QDs) were investigated by means of single dot spectroscopy. By systematically changing a bias applied to the sample, successive energy shifts of the photoluminescence (PL) peaks from excitons and biexcitons due to the quantum confined Stark effect were clearly observed. The quadratic Stark coefficient was evaluated to be of the order of 10-31 Fcm2. The energy separation of the PL peaks arising from the excitons and biexcitons changed with the applied electric field, reflecting a slight difference of the Stark coefficient between the exciton and biexciton states. The existence of permanent dipole moments was also revealed in both the exciton and biexciton states. The spatial separations between the electrons and holes along the growth direction in a QD were estimated to be 7 Å for the exciton state, and 8 Å for the biexciton state. Further, the diamagnetic shift and the Zeeman splitting of the exciton states were clearly observed in a magnetic field. It was found that the diamagnetic coefficient gradually decreases on decreasing the QD size. A simple qualitative model can explain that this result is due to competition between quantum confinement and magnetic confinement.

著者

武田 俊昭 Toshiaki Takeda

雑誌

人文論究 (ISSN:02866773)

巻号頁・発行日

vol.24, no.1, pp.44-59, 1974-05-05

著者

中西 みゆき

出版者

筑波社会学会

雑誌

年報筑波社会学 (ISSN:09163336)

巻号頁・発行日

no.10, pp.95-112, 1998-10

著者

ヴルフ クリストフ 今井 康雄

出版者

東京大学大学院教育学研究科教育学研究室

雑誌

研究室紀要 (ISSN:02857766)

巻号頁・発行日

vol.35, pp.125-133, 2009-03-31

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翻訳

著者

Tomimoto Shinichi Kurokawa Atsushi Sakuma Yoshiki Usuki Tatsuya Masumoto Yasuaki

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.76, no.20, pp.205317, 2007-11

被引用文献数

14 10

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Recombination dynamics of excitons confined in disk-shaped InAs/InP quantum dots is studied by time-resolved photoluminescence measurements. By comparing the result with that in a homologous ultrathin quantum well, it is revealed that the lateral confinement of excitons suppresses the thermal variation of the radiative recombination lifetime. The oscillator strength of the radiative transition is reduced with the decrease of the disk height, which is attributed to the increasing tunneling into the InP barrier of the exciton wave function.

著者

安藤 泰至

出版者

京都大学文学研究科宗教学専修

雑誌

宗教学研究室紀要 (ISSN:18801900)

巻号頁・発行日

vol.7, pp.28-42, 2010-12-03

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本稿は、ウィリアム・R.ラフルーア氏が2009年2月21日に京都大学で行った講演、‘Peripheralized in America: Hans Jonas as Philosopher and Bioethicist'「アメリカにおける周縁的地位―哲学者および生命倫理学者としてのハンス・ヨナス―」(以下「講演」と略記)において、コメンテータの一人を務めた筆者のコメントを中心に文章化したものである。本号にはラフルーア氏の講演原稿全文が掲載されているので、コメントの対象となった氏の講演内容についての記述、要約は必要最小限にとどめ、筆者が講演当日に用意したメモに基づいて、コメント内容を文章化した。したがって、本稿は当日のコメントそのものの再現ではないが、筆者の提示している論点は基本的に当日のそれと同じである。ただし、バイオエシックス(生命倫理学)の歴史やこの分野でのヨナスの論考に不慣れな読者のために、若干の補足説明を加えた。また、提示した論点の相互関係についての記述には、当日のコメントでは触れなかったが、後になって筆者が気づいた点がいくらか含まれていること、コメントの最後でラフルーア氏に問いかけた問い(現代の生命倫理の議論においてヨナスのような声がどのように生かされうるか)についての筆者自身の考えを、本稿の末尾で述べさせていただいたことをお断りしておく。

著者

三松 幸雄

出版者

東京大学教養学部哲学・科学史部会

雑誌

哲学・科学史論叢 (ISSN:13446185)

巻号頁・発行日

vol.8, pp.79-137, 2006-01-31

著者

杉崎 泰一郎

出版者

日本基督教学会北海道支部/北海道基督学会

雑誌

基督教学 (ISSN:02871580)

巻号頁・発行日

vol.28, pp.1-15, 1993-07-05

著者

Ryu S. Hatsugai Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.73, no.24, pp.245115, 2006-06

被引用文献数

138

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The entanglement entropy (von Neumann entropy) has been used to characterize the complexity of many-body ground states in strongly correlated systems. In this paper, we try to establish a connection between the lower bound of the von Neumann entropy and the Berry phase defined for quantum ground states. As an example, a family of translational invariant lattice free fermion systems with two bands separated by a finite gap is investigated. We argue that, for one-dimensional (1D) cases, when the Berry phase (Zak's phase) of the occupied band is equal to pi×(odd integer) and when the ground state respects a discrete unitary particle-hole symmetry (chiral symmetry), the entanglement entropy in the thermodynamic limit is at least larger than ln 2 (per boundary), i.e., the entanglement entropy that corresponds to a maximally entangled pair of two qubits. We also discuss how this lower bound is related to vanishing of the expectation value of a certain nonlocal operator which creates a kink in 1D systems.

著者

林 行夫

出版者

京都大学東南アジア研究センター

雑誌

東南アジア研究 (ISSN:05638682)

巻号頁・発行日

vol.35, no.4, pp.684-715, 1998-03

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この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。

著者

辻村 優英

出版者

宗教倫理学会

雑誌

宗教と倫理 (ISSN:13468219)

巻号頁・発行日

vol.12, pp.77-98, 2012-10

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近代の科学技術や経済活動等に大きく依存する地球環境問題(global environmental issues)の解決に向けて、様々な学問分野からのアプローチが試みられている。宗教学もその例に漏れず、諸宗教と環境との関わりについての研究(例えば、Harvard University Pressから出されているReligions of the World and Ecologyシリーズ)がなされている。そうしたなかで、本論文が目的とするのは、地球環境問題に対する仏教的アプローチの一例としてダライ・ラマ14世の環境思想を取り上げ、その輪郭を描くことにある。彼が示唆する環境思想は、非暴力によって特徴付けられる。非暴力の対象となるのは有情であるが、その際問題となるのは植物の位置づけである。中国・日本には草木成仏思想があるけれども、ダライ・ラマにおいてはそうではなく、植物は有情に含まれない。結果、植物は縁起の論理を媒介することにより、環境思想の中に組み込まれることとなる。

著者

Matsuda Tadashi Sakakibara Jun

出版者

American Institute of Physics

雑誌

Physics of fluids (ISSN:10706631)

巻号頁・発行日

vol.17, no.2, pp.025106, 2005-01

被引用文献数

48 41

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Turbulent vortical structures in a round free jet of water were experimentally visualized by using stereo particle image velocimetry (PIV). A laser light sheet illuminated a cross-sectional plane normal to the axis of the jet, and two charge-coupled device cameras captured particle images in the same region of interest but from different directions. The stereo-PIV algorithm had been applied to obtain two-dimensional, three-component (2D-3C) velocity distributions on various cross-sectional planes along the axis downstream. All nine components of the velocity gradient tensor were reconstructed from time-dependent 2D-3C velocity data by locally assuming Taylor's frozen field hypothesis based on the convective velocity evaluated from the mean flow profile. Isosurfaces of the swirling strength lambdai revealed that the existence of a group of hairpinlike vortex structures was quite evident around the rim of the shear layer of the jet. The center of curvature of the head of the hairpin was typically observed around r/b = 1.5, and the azimuthal spacing between the legs of the hairpin was roughly 0.9b. A similar hairpin structure was estimated by linear stochastic estimation. The typical spacing between the legs of the estimated hairpin was 0.65b, which is generally constant over the range of Re = 1500–5000.

著者

野村 圭介

出版者

早稲田商学同攻會

雑誌

文化論集 = The Cultural review (ISSN:09184589)

巻号頁・発行日

vol.22, pp.117-140, 2003-03

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研究ノート

著者

佐藤 昭宏

出版者

北海道大学大学院教育学研究院

雑誌

北海道大学大学院教育学研究院紀要 (ISSN:18821669)

巻号頁・発行日

vol.117, pp.147-170, 2012-12-26

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困難な状況にあるとされる教員を如何に支援するかを考えるにあたり,これまでの先行研究の蓄積の結果,職員室という環境が注目を集めることが多くなってきた。しかしこれまで,職員室を,実際にその場を構成する当事者である教員の立場から検討しようとする研究はほとんど見られなかった。 そうした状況を鑑み,本論文においては,当事者である教員が職員室という場を如何に意味づけているかということを検討することの意義について,まず論じた。そしてその意味づけを考察するにあたっては,教員による「語り」,「言葉」を研究対象とすべきことを,言葉を,それを語る者の「世界の見方」としたBakhtin の言語論,更にMoos による社会的風土概念から示した。 本論文は,今後の職員室研究が如何に進展すべきかを,先行研究のレビューを基に理論的に検討したものである。

著者

Hattori Toshiaki

出版者

American Institute of Physics

雑誌

The journal of chemical physics (ISSN:00219606)

巻号頁・発行日

vol.133, no.20, pp.204503, 2010-11

被引用文献数

9

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A general theoretical framework of two-dimensional time-domain second-order and third-order terahertz spectroscopy has been presented. The theoretical treatment is based on a classical and phenomenological model with weak nonlinearities. Three types of nonlinearity sources, anharmonicity, nonlinear coupling, and nonlinear damping, were considered. The second-order THz spectroscopy has an exact correspondence to fifth-order off-resonance Raman spectroscopy, and it has been shown that the present treatment gives exactly the same results as of the quantum mechanical theory under the weak nonlinearity condition. General expressions for the nonlinear signal have been obtained for a single-mode system, and numerical calculations for delta-function incident terahertz pulses were shown. For the third-order signal, two-level systems were also considered for comparison. Contributions of two types of incident pulse sequences have been studied separately in the third-order signals. Profiles of the two-dimensional signals were found to depend on the origin and order of the nonlinearity and also on the pulse sequence. The results of the present study show that the two-dimensional signal features of second- and third-order nonlinear terahertz spectroscopy can clarify the nature of the system which is not accessible using linear spectroscopy.

著者

Tsai Melody Ohniwa Ryosuke L Kato Yusuke Takeshita Sayaka L Ohta Toshiko Saito Shinji Hayashi Hideo Morikawa Kazuya

出版者

BioMed Central

雑誌

BMC microbiology (ISSN:14712180)

巻号頁・発行日

vol.11, pp.13, 2011-01

被引用文献数

100 26

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BackgroundThe ability of staphylococci to grow in a wide range of salt concentrations is well documented. In this study, we aimed to clarify the role of cardiolipin (CL) in the adaptation of Staphylococcus aureus to high salinity.ResultsUsing an improved extraction method, the analysis of phospholipid composition suggested that CL levels increased slightly toward stationary phase, but that this was not induced by high salinity. Deletion of the two CL synthase genes, SA1155 (cls1) and SA1891 (cls2), abolished CL synthesis. The cls2 gene encoded the dominant CL synthase. In a cls2 deletion mutant, Cls1 functioned under stress conditions, including high salinity. Using these mutants, CL was shown to be unnecessary for growth in either basal or high-salt conditions, but it was critical for prolonged survival in high-salt conditions and for generation of the L-form.ConclusionsCL is not essential for S. aureus growth under conditions of high salinity, but is necessary for survival under prolonged high-salt stress and for the generation of L-form variants.

著者

米虫 正巳 Masami Komemushi

雑誌

人文論究 (ISSN:02866773)

巻号頁・発行日

vol.56, no.3, pp.1-22, 2006-12-10

著者

米虫 正巳 Masami Komemushi

雑誌

人文論究 (ISSN:02866773)

巻号頁・発行日

vol.55, no.3, pp.1-20, 2005-12-10

著者

張 文青

巻号頁・発行日

pp.91-105, 2010-10

著者

Ishizuka Shogo Yamada Akimasa Islam Muhammad Monirul Shibata Hajime Fons Paul Sakurai Takeaki Akimoto Katsuhiro Niki Shigeru

出版者

American Institute of Physics

雑誌

Journal of applied physics (ISSN:00218979)

巻号頁・発行日

vol.106, no.3, pp.034908, 2009-08

被引用文献数

144 57

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The systematic variations in the structural, optical, and electrical properties of polycrystalline Cu(In,Ga)Se2 (CIGS) thin films with Na doping level were investigated. Precise control of the Na concentration in CIGS films was demonstrated using alkali-silicate glass thin layers of various thicknesses deposited on substrates prior to CIGS growth. The CIGS grain size was observed to decrease with increasing Na concentration, although the surface morphology became smoother and exhibited a stronger (112) texture, which has been demonstrated consequence of larger grain size. The Ga composition gradient in the CIGS films was found to become large due to the presence of Na during growth, which in turn led to a decrease in the nominal band gap energy. Variations in the photoluminescence spectra and electrical properties suggested that the formation of an acceptor energy state, which may originate from OSe point defects, was enhanced in the presence of Na. This result suggests that not only Na, but also the presence of O in combination with Na contributes to the compensation of point defects and enhances p-type conductivity in CIGS films.