Влияние толщины диффузионного слоя на возникновение динамических неустойчивостей в модельном электрокаталитическом процессе

Определено влияние толщины диффузионного слоя Нернста на возникновение неустойчивостей Хопфа, седло–узел и гомоклинной неустойчивости в модельном электрокаталитическом процессе на поверхности сферического электрода при потенциостатических условиях. Показано, что увеличение толщины диффузионного слоя Нернста способстует расширению области потенциалов (в системе могут наблюдаться спонтанные периодические колебания тока), а также области бистабильности системы. Возможная реализация в системе гомоклинной бифуркации может привести и к более сложным динамическим режимам.Визначено вплив товщини дифузійного шару Нернста на виникнення нестійкості Хопфа, сідло–вузол та гомоклінної нестійкості в модельному електрокаталітичному процесі на поверхні сферичного електроду за потенціостатичних умов. Показано, що збільшення товщини дифузійного шару Нернста спричинює розширення області потенціалів (у системі можуть спостерігатися спонтанні періодичні коливання струму), а також області бістабільності системи. Можлива реалізація в системі гомоклінної біфуркації може привести і до більш складних динамічних режимів.The influence of the Nernst diffusion layer thickness on the appearance of the Hopf instability, saddle–node instability, and homoclinic instability in a model electrocatalytic process on a spherical electrode surface under potentiostatic conditions is determined. It is shown that the Nernst diffusion layer thickness increase leads to an increase in the potential range, where spontaneous periodic current oscillations can be observed and also in the system bistability range. A possible realization of the homoclinic bifurcation in the system can initiate more complicated dynamical regimes

[研究ノート] 日本における1950年以降の重大バス事故の一覧

It is important for preventing bus accidents to extract many accidents that occurred in the past and to analyze them systematically. However there is no historical statistical data on serious bus accidents in Japan. In this paper, we show a list of 362 serious bus accidents that have occurred since 1950.departmental bulletin pape

高感度・高解像度元素マッピング像観察の研究

1.元素マッピング専用検出器の開発:(1)検出システムの構築;パラレル電子エネルギ-損失分光法(PEELS)と走査透過電子顕微鏡(STEM)を組み合わせて,元素濃度を像の濃淡として表す元素マッピング法を高速に行うため,35チャンネルと少ない素子数のフォトダイオ-ドアレイ(PDA)を用いてエネルギ-損失スペクトルをコンピュ-タに取り込み,元素マッピング像を表示する検出器,制御・増幅回路及びソフトウェアからなるシステムを開発した.1 画素当たりのスペクトル獲得時間は約1.2msecと通常の1024チャンネルのPDAより20倍高速である.(2)検出器の基本特性の測定;電子線シンチレ-タからの光が屈折のためにPDAの窓と受光面の間で広がり,大きなチャンネル間クロスト-クとなることを見出した.その対策として窓のないPDAを用意し,光の漏れを低減した結果,チャンネル間クロスト-クは4%と低い値とすることができた.また,検出器の検出量子効率(DQE)を測定し,実際に元素マッピングを行う低い電子強度では検出回路における電磁的擾乱のためDQEが低下しており,より強力な電磁シ-ルドを行う必要があることが分った. 2.薄膜レンズを用いた球面収差補正による高電流密度電子プロ-ブの実現:散乱断面積の低い高エネルギ-損失の内殻励起エッジを用いて高解像度元素マッピングを行うために,電子レンズの球面収差を薄膜レンズを用いて補正できることを実験と計算により明らかにし,高電流密度の微小電子プロ-ブを実現した. 3.元素マッピング像の観察:実際にカ-ボンマイクログリッド上の窒化ボロンの元素マッピング像を観察し,カ-ボンと窒素・ボロンの分離された像を得た. また,酸化ニッケルを観察した結果,スペクトル強度の低い酸素やニッケルについてもマッピング像が得られ,PEELSを用いた高感度の元素マッピングが達成できた.科学研究費補助金 研究種目:一般研究(B) 課題番号:04452103 研究代表者:日比野 倫夫 研究期間:1992-1993年度research repor

The SOS-framework (Systems of Sedentary behaviours): An international transdisciplinary consensus framework for the study of determinants, research priorities and policy on sedentary behaviour across the life course: A DEDIPAC-study

© 2016 The Author(s).Background: Ecological models are currently the most used approaches to classify and conceptualise determinants of sedentary behaviour, but these approaches are limited in their ability to capture the complexity of and interplay between determinants. The aim of the project described here was to develop a transdisciplinary dynamic framework, grounded in a system-based approach, for research on determinants of sedentary behaviour across the life span and intervention and policy planning and evaluation. Methods: A comprehensive concept mapping approach was used to develop the Systems Of Sedentary behaviours (SOS) framework, involving four main phases: (1) preparation, (2) generation of statements, (3) structuring (sorting and ranking), and (4) analysis and interpretation. The first two phases were undertaken between December 2013 and February 2015 by the DEDIPAC KH team (DEterminants of DIet and Physical Activity Knowledge Hub). The last two phases were completed during a two-day consensus meeting in June 2015. Results: During the first phase, 550 factors regarding sedentary behaviour were listed across three age groups (i.e., youths, adults and older adults), which were reduced to a final list of 190 life course factors in phase 2 used during the consensus meeting. In total, 69 international delegates, seven invited experts and one concept mapping consultant attended the consensus meeting. The final framework obtained during that meeting consisted of six clusters of determinants: Physical Health and Wellbeing (71 % consensus), Social and Cultural Context (59 % consensus), Built and Natural Environment (65 % consensus), Psychology and Behaviour (80 % consensus), Politics and Economics (78 % consensus), and Institutional and Home Settings (78 % consensus). Conducting studies on Institutional Settings was ranked as the first research priority. The view that this framework captures a system-based map of determinants of sedentary behaviour was expressed by 89 % of the participants. Conclusion: Through an international transdisciplinary consensus process, the SOS framework was developed for the determinants of sedentary behaviour through the life course. Investigating the influence of Institutional and Home Settings was deemed to be the most important area of research to focus on at present and potentially the most modifiable. The SOS framework can be used as an important tool to prioritise future research and to develop policies to reduce sedentary time

Optical Characterization of SiC Whiskers Grown on 3C-SiC Films and their Usefulness for Single Photon Sources

Single Photon Source (SPS) has been adopted as a quantum information and communication technology for quantum cryptography and quantum computing. Although defects in SiC films are currently studied in SPS, there is difficulty in fabricating such defects under controlled conditions. SiC whiskers (SiC-Wk) have the potential to overcome this difficulty. In this study, we investigated the photoluminescence (PL) of SiC-Wk and discussed whether it could be used as SPS or not. The SiC-Wk were grown on the 3C-SiC films deposited on epitaxially grown 3C-SiC/Si substrates using monomethylsilane gas at 750 °C. When the temperature increased to 800 °C, only 3C-SiC films were deposited. The latter samples with no whiskers were used as a reference. In the observed PL spectra measured at low temperatures, broad luminescence attributed to the lattice defect levels of the 3C-SiC film was observed regardless of the whisker formation. By subtracting the luminescence contribution of 3C-SiC film, small emission peaks at 628 and 654 nm were observed for the whisker samples. Comparing to the reported PL spectra from the defect in SiC in the literature, we found that observed two luminescence peaks from the whiskers are available as SPS. Since defects are usually difficult to control, the usefulness of the whiskers is demonstrated.departmental bulletin pape

Observation of the Decay B0→D±D*∓

journal articl

Effect of Excitation Light Intensity on Temperature Dependence of Photoluminescence Peak Energy in GaAs Quantum Dots

Photoluminescence (PL) measurements of GaAs quantum dots (QDs) were carried out from 4 K to room temperatures. The results showed an unusual temperature dependence of the PL peak energy. When the temperature increased, the peak energy showed a red-shift from the so-called Varshni's curve around 50 K followed by an additional blue-shift above 150K. This unusual temperature dependence has been explained by using a steady-state model with the size distribution of the QDs. Our recent model calculation revealed that the shift of the peak energy from Varshni’s curve should be decreased when a sufficient number of carriers are supplied to the QDs. Therefore, PL measurements with changing the excitation intensity were performed. Although the expected decrease was experimentally confirmed, the amount of the shift was not sufficient to explain the obtained data by our steady-state model. Therefore, we considered a modified model where the three kinds of size distribution functions appeared in the QDs. This is because the PL spectra at 4 K seem to be decomposed into three broad peaks and the atomic-force-microscopy measurements suggested that the size distribution consisted of three dominant maxima. This model is easier for understanding the capture and emission of the photoexcited carriers in the QDs. The results showed that observed unusual temperature dependence was explained by considering both the size distribution of the QDs as well as the carrier redistribution caused by the capture and the emission processes between the QDs and the barrier layer.departmental bulletin pape

<教育デザインフォーラム学生発表会>ソーシャル・プラクティスとしてのアートと教育(ポスター発表の要旨)

departmental bulletin pape

Baseline and post-intervention mean scores (SD) or percentages for compliance with the MVPA guideline, minutes spend in MVPA, weight status and waist-circumference and unstandardized regression coefficients from the regression analyses with GI group as reference.

<p>MVPA = moderate-to-vigorous physical activity, WC = waist circumference, GI = general information; SD = standard deviations; N = number of adolescents; k = number of classes;</p><p>* = p<0.05;</p>†<p>multilevel linear or logistic regression analyses with class and individual as levels, adjusted for level of education.</p

Self-reported and objectively measured exposure to intervention content by intervention group and differences between intervention groups.

<p>GI = general information; SD = standard deviation; N = number of adolescents; k = number of classes;</p>†<p>based on one-way ANOVA;</p>‡<p>based on chi-square tests.</p