著者

スティーブンT.ソニス ロバートC.ファジオ レスリーS.T.ファン著 島原政司 勝健一監訳

出版者

メディカル・サイエンス・インターナショナル

巻号頁・発行日

2004

著者

喜田 宏 YAMNIKOVA Sv 河岡 義裕 高田 礼人 岡崎 克則 SVETRANA Yam デメネフ V. ヤムニコバ S. ルボフ D.K. 伊藤 壽啓

出版者

北海道大学

雑誌

国際学術研究

巻号頁・発行日

1995

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平成7〜9年夏、カムチャッカ半島南端付近、ハバロフスク郊外のアムール河流域ならびにサハ自治共和国内のレナ河流域において水禽の糞便および湖沼水3,000検体を採取した。8年にはレナ河流域北緯63度30分のコベイスキー地区で採取した約900検体の水禽糞便からインフルエンザウイルスH4N6亜型19株、H4N9亜型1株、H11N1亜型1株、H11N6亜型2株、H11N9亜型8株を分離した。9年にはコベイスキー地区で採取した水禽糞便120検体およびヤク-ツク(北緯62度)で採取した鴨の糞便72検体からは各々H4N6亜型1株およびH3N8亜型5株が分離された。一方、レナ河流域北緯65度00分〜64度36分の四十諸鳥地域で採取した水禽糞便約1,400検体と湖沼水20検体からはウイルスが分離されなかった。カムチャッカ半島ならびにアムール河流域で採取した水禽糞便からインフルエンザウイルスは分離されなかった。以上の成績は、鴨の営巣湖沼がレナ河流域北緯63度付近に存在することを示唆する。平成8年と9年の10月に北海道宗谷地方において採取した480検体の水禽糞便材料からインフルエンザウイルスH1N1亜型、H5N3亜型、H5N4亜型、H6N1亜型、H6N7亜型、H8N1亜型、H8N3亜型、H9N2亜型ならびにH11N9亜型各1株を分離した。平成8年度および9年度にレナ河流域および北海道の水禽糞便から分離したインフルエンザウイルスのNP遺伝子の系統進化解析を実施した。その結果、調べた分離株すべてが新型インフルエンザウイルスの発生地である中国南部を含むアジア大陸に分布するウイルスの系統に属することが判明した。以上の成績は、新型インフルエンザウイルスの抗原亜型を予測するために、シベリアの水禽営巣地におけるインフルエンザウイルスの分布をさらに解明する必要があることを示している。

著者

Hurley D. H. Wright O. B. Matsuda O. Shinde S. L.

出版者

American Institute of Physics

雑誌

Journal of Applied Physics (ISSN:00218979)

巻号頁・発行日

vol.107, no.2, pp.023521, 2010-01-15

被引用文献数

23

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We use ultrashort optical pulses to microscopically image carrier and thermal diffusion in two spatial dimensions in pristine and mechanically polished surfaces of crystalline silicon. By decomposing changes in reflectivity in the latter sample into a transient component that varies with delay time and a steady-state component that varies with pump chopping frequency, the influence of thermal diffusion is isolated from that of carrier diffusion and recombination. Additionally, studies using carrier injection density as a parameter are used to clearly identify the carrier recombination pathway.

著者

YANG L. W. WRIGHT P. D. SHEN H. LU Y. BRUSENBACK P. R. KO S. K. CALDERON L. HARTZLER W. D. HAN W. Y. DUTTA M. CHANG W. H.

出版者

社団法人応用物理学会

雑誌

Japanese journal of applied physics. Pt. 2, Letters (ISSN:00214922)

巻号頁・発行日

vol.32, no.10, pp.L1400-L1402, 1993-10-01

被引用文献数

1

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Submicron heterojunction bipolar transistors (HBTs) with maximum frequency of oscillation, f_<MAX>, of 91 GHz have been fabricated using a self-aligned technique and a very heavily carbon-doped (10^<20> cm^<-3>) base layer. Since the quenching of photoluminescence (PL) intensity in heavily-doped Cabs is mainly due to nonradiative recombination in the bulk material, while contribution from surface recombination is negligible, the use of a heavily carbon-doped base layer in AlGaAs/GaAs HBTs minimizes the influence of surface recombination in the extrinsic base region. Thus, for HBTs with a heavily doped base layer, the "emitter size effect" (degradation of HBT current gain) is greatly reduced when the emitter width is scaled down to submicron (0.6 μm) dimensions.

著者

Casey T. A. Sakakibara J. Thoroddsen S. T.

出版者

American Institute of Physics

雑誌

Physics of fluids (ISSN:10706631)

巻号頁・発行日

vol.25, no.2, pp.025102, 2013-02

被引用文献数

30 1

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We introduce a modified tomographic PIV technique using four high-speed videocameras and a scanning pulsed laser-volume. By rapidly illuminating adjacent subvolumesonto separate video frames, we can resolve a larger total volume of velocityvectors, while retaining good spatial resolution. We demonstrate this technique byperforming time-resolved measurements of the turbulent structure of a round jet,using up to 9 adjacent volume slices. In essence this technique resolves more velocityplanes in the depth direction by maintaining optimal particle image density andlimiting the number of ghost particles. The total measurement volumes contain between1 ×106 and 3 ×106 velocity vectors calculated from up to 1500 reconstructeddepthwise image planes, showing time-resolved evolution of the large-scale vorticalstructures for a turbulent jet of Re up to 10 000.

著者

Yamagata K Arai C Sasaki H Takeuchi Y Onizawa K Yanagawa T Ishibashi N Karube R Shinozuka K Hasegawa Y Chiba S Bukawa H

出版者

Nature Publishing Group

雑誌

Bone marrow transplantation (ISSN:02683369)

巻号頁・発行日

vol.47, pp.725-730, 2012-05

被引用文献数

25 6

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Oral mucositis (OM) is a frequent adverse effect of allogenic or autologous hematopoietic SCT. It results from direct toxic injury to the mucosal epithelial cells by the immunosuppressive regimen. Here, we compared the incidence and severity of OM between a group of 24 patients who received proper oral management during hematopoietic SCT and a group of 24 who did not. The oral management group received pre-hematopoietic SCT instruction on oral care and an oral examination in the clean room. Differences in the incidence and severity of OM between the two groups were examined statistically. OM was observed in 14 (58.3%) patients in the oral management group and 22 (91.6%) in the control group. The median of the OM score was 1 for the oral management group (range 0 to 3) and 2 for the control group (range 0 to 3). There was a significant difference in the OM score (P<0.05) and in the incidence of OM between the two groups (P<0.01). This study shows that oral management may decrease the occurrence of OM. Our results also suggest that it is important to include an oral management provider on the hematopoietic SCT team.

著者

Takahashi Y. Hara K. Kim S. Ikegami Y. Takubo Y. Terada S. Unno Y. Mitsui S. Kamada S. Yamamura K.

出版者

Elsevier B.V.

雑誌

Nuclear instruments & methods in physics research. Section A (ISSN:01689002)

巻号頁・発行日

vol.699, pp.107-111, 2013-01

被引用文献数

1 1

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We are developing p-bulk microstrip sensors for the high luminosity upgrade of the LHC accelerator, HL-LHC. The stability of FZ (float zone) wafers available to Hamamatsu Photonics was examined by irradiating them at rates expected at the HL-LHC. They show degradation in the operational voltage at low dose but recover after the dose is accumulated. The instability is dependent on the bias voltage and dose rate, and also on the irradiation history. We have characterized the instability and attributed the cause to the charge concentration at the electrode edge. The strip isolation, which is degraded while in irradiation, is shown not to induce any practical problem for the operation.

著者

Hara K. Baccehtta N. Spalding W.J. Worm S.D.

出版者

Elsevier B.V.

雑誌

Nuclear instruments & methods in physics research. Section A (ISSN:01689002)

巻号頁・発行日

vol.699, pp.84-88, 2013-01

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On September 30, 2011, the Collider Detector at Fermilab (CDF) finished physics data-taking at the Tevatron proton–antiproton collider. The original CDF silicon tracking detector, proposed in 1981 (SVX) and later replaced and updated (SVX′), was again replaced for Run-2 in 2002–2011 (SVX-II, ISL, L00). These systems operated successfully for many years, performing essential roles in exploring physics at the energy frontier, most notably the discovery of the top quark.

著者

Gerlovin I. Ya. Dolgikh Yu. K. Eliseev S. A. Ovsyankin V. V. Efimov Yu. P. Petrov V. V. Ignatiev I. V. Kozin I. E. Masumoto Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.65, no.3, pp.035317, 2002-01

被引用文献数

21 17

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Picosecond kinetics of polarized resonant photoluminescence (PL) of HH excitons in the GaAs/AlGaAs superlattices is studied in an external magnetic field. The measurements were made in real time using a streak camera. For the magnetic field aligned along the heterostructure growth direction, the resonant PL exhibits oscillations in the degree of linear polarization. The oscillations are ascribed to quantum beats between sublevels of the optically active excitonic doublet split by the magnetic field. For the magnetic field aligned along the plane of the layers, the resonant PL is found to exhibit oscillations in circular polarization. These oscillations are related to beats between states of the optically active and optically inactive excitonic doublets. Experimental dependence of the oscillation frequency on the magnetic field strength and orientation has allowed us to determine the hole and electron g factors and the electron-hole exchange energy. Dynamics of the degree of circular polarization of the PL in magnetic field is used to measure the energy relaxation rate of the exciton spin states. In the magnetic field exceeding 1 T, the energy relaxation rate is shown to be magnetic-field independent and equal (1±0.2)×1010 s-1. This value is found to be much smaller than the spin phase relaxation rate determined from decay of the quantum beats in linear polarization. Unlike the energy relaxation rate, the latter grows linearly with the field strength and equals (5±0.5)×1010 s-1 at 5 T. It is concluded that the main mechanism responsible for loss of macroscopic spin coherence is the reversible dephasing within inhomogeneously broadened system.

著者

Kozin I. E. Davydov V. G. Ignatiev I. V. Kavokin A. V. Kavokin K. V. Malpuech G. Ren Hong-Wen Sugisaki M. Sugou S. Masumoto Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.65, no.24, pp.241312, 2002-06

被引用文献数

61 53

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Spins of resident electrons in charged quantum dots (QD’s) act as local magnets inducing the Zeeman splitting of excitons trapped into dots. This is evidenced by the observation of quantum beats in the linearly polarized time-resolved photoluminescence of a biased array of self-assembled InP QD’s. An external magnetic field is found to shorten the spin beats’ decay time keeping constant the frequency of the beats. A model using the pseudospin formalism allows one to attribute the observed quantum beats to the radiative decay of hot trions having two electrons that occupy different energy levels in a QD.

著者

Hatsugai Y. Ryu S.

出版者

American Physical Society

雑誌

Physical review B (ISSN:01631829)

巻号頁・発行日

vol.65, no.21, pp.212510, 2002-06

被引用文献数

13 13

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Topological quantum phase transitions in superconductivity are discussed on two-dimensional lattices. The main focus is on the Chern number for superconducting states. Each superconductivity is characterized by the Chern number, and the quantum phase transition is associated with topological changes of the quasiparticle Bloch function in the Brillouin zone. For the superconducting case, the Chern number has several equivalent but different topological expressions given by vortices, the Dirac monopole, and strings. We demonstrate quantum phase transitions by these topological quantities both for singlet and triplet cases.

著者

Sakai S. Tanimoto H. Kita E. Mizubayashi H.

出版者

American Physical Society

雑誌

Physical review B (ISSN:01631829)

巻号頁・発行日

vol.66, no.21, pp.214106, 2002-12

被引用文献数

16 17

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Nanocrystalline (n) Au specimens with a density of 19.4±0.2 g/cm3 and a mean grain size of about 20 nm were prepared below 300 K by the gas deposition method, where two types of n-Au specimens were obtained as a function of a deposition rate, the type-H specimens above 800 nm/s and the type-L specimens below 800 nm/s. The anelastic and the plastic creep responses are similar qualitatively but different quantitatively between the type-H and type-L specimens. The anelastic strain ɛan,GB, associated with the grain boundary (GB) regions, increases linearly with (T-Tan1)(σap-σan1), when the temperature T is higher than a threshold temperature Tan1 of 200 K and the applied stress σap is higher than a threshold stress, σan1, of a few MPa. The ratio of ɛan,GB to the elastic strain is as large as 1.1 for the type-H specimens and 0.2 for the type-L specimens at 320 K for σap≫σan1. The activation energy for the GB anelastic process is 0.2 eV. We surmise that cooperative motions of many atoms in the GB regions are responsible for ɛan,GB, and both Tan1 and σan1 show a distribution depending on the number of atoms associated. The plastic creep rate ɛ′ vs σap data show a letter S-like curve. We classified the creep response into three categories, region I for the linear creep rate region for σap between σpc 1 and σpc2, region II for the transient creep rate region for σap between σpc2 and σpc3, and region III for the saturation creep rate region for σap between σpc3 and σy. The threshold stresses σpc1 and σpc2 and the yield stress σy are about 30, 150, and 360 MPa for the type-H specimens, and about 60, 300, and 500 MPa for the type-L specimens, respectively. σpc3 is slightly lower than σy. From scanning tunneling microscopy images, we surmise that the localized GB slip takes place in region I, and the mean separation between the localized GB slips decreases with increasing σap in region II and becomes comparable with the mean grain size in region III. The plastic creep in region III may be explained by the Ashby creep. The present view for the creep behavior explains the low-temperature creep behavior of fcc n metals.

著者

Yugova I. A. Gerlovin Ya. Davydov V. G. Ignatiev I. V. Kozin I. E. Ren H. W. Sugisaki M. Sugou S. Masumoto Y.

出版者

American Physical Society

雑誌

Physical review B (ISSN:10980121)

巻号頁・発行日

vol.66, no.23, pp.235312, 2002-12

被引用文献数

37 36

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The paper reports on quantum beats observed in the photoluminescence kinetics of a single layer of the InPself-assembled quantum dots in a magnetic field. It is found that the beats arise only after removal of excesscharges from the quantum dots by an external electrical bias. The quantum beats are shown to be related to theinterference of the excitonic fine-structure states split by the magnetic-field. The dependences of the beatcharacteristics on the magnetic-field strength and orientation are studied. Theoretical analysis based on a modelspin Hamiltonian has allowed us to describe adequately the shape of the oscillating component of the signal.We have determined the values of the electron g-factor components and estimated the spread and the meanvalue of the hole g factor, as well as of the electron-hole exchange splitting parameters.

著者

Mirković J. Savel’ev S. E. Sugahara E. Kadowaki K.

出版者

American Physical Society

雑誌

Physical review B (ISSN:01631829)

巻号頁・発行日

vol.66, no.13, pp.132505, 2002-10

被引用文献数

13 12

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The vortex-liquid and vortex-solid phases in single crystals of Bi2Sr2CaCu2O8+δ placed in tilted magnetic fields are studied by in-plane resistivity measurements using the Corbino geometry to avoid spurious surface-barrier effects. It was found that the anisotropy of the vortex-solid phase increases with temperature and exhibits a maximum at T≈0.97Tc. In contrast, the anisotropy of the vortex-liquid phase rises monotonically across the whole measured temperature range. The observed behavior is discussed in the context of dimensional crossover and thermal fluctuations of vortices in the strongly layered system.

著者

ロビンズ ルイーズ・S 川崎 良孝

出版者

生涯教育学講座紀要編集委員会事務局

雑誌

京都大学生涯教育学・図書館情報学研究 (ISSN:13471562)

巻号頁・発行日

vol.3, pp.189-199, 2004-03-31

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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

原 宏 北山 響 大原 信 佐藤 春菜 太田 将伍 木村 祐樹 毛利 武史 山下 雄太郎 Rao P. S. P. 仲山 伸次

出版者

社団法人大気環境学会

雑誌

大気環境学会年会講演要旨集

巻号頁・発行日

no.50, 2009-08-20

著者

Daugsch A. Moraes C.S. Fort P. Park Y.K.

出版者

玉川大学ミツバチ科学研究所

雑誌

ミツバチ科学 = Honeybee science (ISSN:03882217)

巻号頁・発行日

vol.27, no.2, pp.55-62, 2007-02 (Released:2011-03-05)

著者

Machida Y. Sasaki S. Fujii H. Furuyama M. Kakeya I. Kadowaki K.

出版者

American Physical Society

雑誌

Physical review B (ISSN:01631829)

巻号頁・発行日

vol.67, no.9, pp.094507, 2003-03

被引用文献数

31 37

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We synthesized single crystalline MgB2 under ambient pressure by using conventional materials and equipment. The single crystals of MgB2 were of good quality, where the crystal structure refinements were successfully converged with R=0.020. The measurements of the magnetic properties yielded a sharp superconducting transition at 38 K with transition width ΔTc=0.8 K. The upper critical field for applied field parallel to the ab plane (Hc2ab) reveals a positive curvature, while Hc2 parallel to the c axis (Hc2c) increases linearly in temperature dependence, which yields a temperature dependence of the superconducting anisotropy ratio of γ=Hc2ab/Hc2c with γ∼1 near Tc and 4.0 at 25 K.

著者

Aoki S. Fukugita M. Ishikawa K-I. Ishizuka N. Iwasaki Y. Kanaya K. Kaneko T. Kuramashi Y. Okawa M. Ukawa A. Yamazaki T. Yoshié T.

出版者

American Physical Society

雑誌

Physical review D (ISSN:15507998)

巻号頁・発行日

vol.71, no.9, pp.094504, 2005-05

被引用文献数

68

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We calculate the two-pion wave function in the ground state of the I=2 S-wave system and find the interaction range between two pions, which allows us to examine the validity of the necessary condition for the finite-volume method for the scattering length proposed by Lüscher. We work in the quenched approximation employing a renormalization group improved gauge action for gluons and an improved Wilson action for quarks at 1/a=1.207(12) GeV on 163×80, 203×80, and 243×80 lattices. We conclude that the necessary condition is satisfied within the statistical errors for the lattice sizes L>=24 (3.92 fm) when the quark mass is in the range that corresponds to mpi2=0.273–0.736 GeV2. We obtain the scattering length with a smaller statistical error from the wave function than from the two-pion time correlator.

著者

Yamada N. Aoki S. Fukugita M. Hashimoto S. Ishikawa K-I. Ishizuka N. Iwasaki Y. Kanaya K. Kaneko T. Kuramashi Y. Okawa M. Taniguchi Y. Tsutsui N. Ukawa A. Yoshié T.

出版者

American Physical Society

雑誌

Physical review D (ISSN:15507998)

巻号頁・発行日

vol.71, no.5, pp.054505, 2005-03

被引用文献数

16 19

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We perform a nonperturbative determination of the O(a)-improvement coefficient cSW for the Wilson quark action in three-flavor QCD with the plaquette gauge action. Numerical simulations are carried out in a range of beta=12.0–5.2 on a single lattice size of 83×16 employing the Schrödinger functional setup of lattice QCD. As our main result, we obtain an interpolation formula for cSW and the critical hopping parameter Kc as a function of the bare coupling. This enables us to remove the O(a) scaling violation from physical observables in future numerical simulation in the wide range of beta. Our analysis with a perturbatively modified improvement condition for cSW suggests that finite volume effects in cSW are not large on the 83×16 lattice. We investigate Nf dependence of cSW by additional simulations for Nf=4, 2, and 0 at beta=9.6. As a preparatory step for this study, we also determine cSW in two-flavor QCD at beta=5.2. At this beta, several groups have carried out large-scale calculations of the hadron spectrum, while no systematic determination of cSW has been performed.