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粒界性格を制御した金属材料設計・開発に対する原子シミュレーションによる基礎的研究
Get PDF非対称傾角粒界の粒界構造と変形メカニズムについて詳細な検討を行ない,以下の結果を得た.
1)対称粒界面からのずれ角度と粒界エネルギーの関係を原子モデルを用いて計算し,ずれ角度増加に伴い粒界エネルギーが増加することを確認した.また,非対称傾角粒界において対称面からのずれを緩和するために導入される欠陥構造(DSC転位)が,結晶方位によっては,転位源としての役割を示すことを確認した.
2)同じ粒界方位差,異なる対称粒界面からのずれ角度を有するアルミニウムの粒界モデルを作成し,せん断変形シミュレーションを実行することで,粒界変形とそのずれ角度依存性を検討した.300K一定の条件では,解析モデルにせん断変形を与えると,粒界移動が生じ,結晶方位が隣接結晶方位に変化することにより,せん断ひずみを稼ぐことを確認した.また,この粒界移動量は対称面からのずれ角度に強く依存し,粒成長等の粒界移動を伴なう現象に対してずれ角度を考慮することは重要であることを見出した.また,高温でせん断変形を加えた場合,ずれ角度の小さな粒界では,前述した粒移動を生じるが,ずれ角度の大きな粒界では粒界すべりが生汁ことを確認し,粒界変形モードが粒界構造に伴ない遷移することを示した.
3)刃状転位と非対称傾角粒界の相互作用シミュレーションを原子・連続体結合モデルで行ない,(a)パイルアップによる応力集中の粒界構造依存性は大きくないこと,(b)粒界より転位を放出するための臨界力が粒界構造に依存し,転位論で見積もれる臨界力とは異なること,(c)粒界に侵入してくる転位のアコモデーション機構は粒界構造に強く依存し,特に非対称傾角粒界を構成する粒界転位の運動が重要であることを示した.研究課題/領域番号:16760063, 研究期間(年度):2004 – 2006出典：「粒界性格を制御した金属材料設計・開発に対する原子シミュレーションによる基礎的研究製」研究成果報告書 課題番号16760063
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-16760063/)を加工して作成金沢大学理工研究域research repor
Mechanical field analysis of lattice defects in nanoscale composite materials
Get PDFナノスケール複合材料中の格子欠陥の非線形力学場を準連続体法と原子モデルを用いて検討した．まず，転位の力学場を解析解を用いずに表現できる準連続体法の開発を行った．それを用いて転位の自己エネルギーの粒径依存性と粒界の剛性率の関係を弾性論的に検討した．つぎに，原子モデルを用いて，粒界構造を直接表現し，粒界内の原子移動が格子転位の力学場を遮蔽できることが明らかになった．さらに，異相界面の結合力の強さが積層構造体の力学特性に与える影響を検討し，界面に侵入した格子転位の芯構造の分解は界面結合力に強く影響を受け，結果的に積層構造体の延性特性に対して界面結合力は重要な設計因子であることを見出した．Non-linear mechanical fields around lattice defects in nano-scale composite materials was investigated by using the quasicontinuum (QC) and atomic simulations. First, the relationship between the grain size dependence of dislocation self-energy and the shear modulus of grain boundary (GB) regions was examined based on an elastic approach by the newly developed QC model. Next, GB structures were directly expressed by using atomic models and it was found that atomic shuffling in GB regions could shield the mechanical field caused by lattice dislocations. Furthermore, the influence of hetero-interface strength on the mechanical properties of multilayered composites was investigated by using atomic simulations. The decomposition of the lattice dislocation core structure at the hetero-interface is strongly affected by the interface strength; hence, the hetero-interface strength is one of the important factors to design an excellent material with high strength and high ductility.研究課題/領域番号:24560091, 研究期間(年度):2012-04-01 - 2015-03-31出典：「ナノスケール複合材料中の格子欠陥力学場解析」研究成果報告書 課題番号24560091
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-24560091/24560091seika/）を加工して作成金沢大学理工研究域機械工学系research repor
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Atomic- and Molecular-level study of connection and propagation mechanisms of local plastic deformations in crystal and polymer structures
Get PDFナノ結晶や非晶質ポリマー等の様々な構造の固体材料が示す類似した速度に依存する変形・破壊モードの遷移現象を,各原子・分子構造に基づいて理解することを目的とすし,分子動力学法を用いた計算機実験を行なった.その結果,格子欠陥や分子鎖形状の局所的な形態変化(例えば,面欠陥と線欠陥の形態変化)に対する容易さが,局所塑性変形の発生や伝ぱに強く関係していることを解明した.In order to elucidate the transition mechanism from homogeneous to inhomogeneous of deformation and fracture modes related to the strain rate and temperature in nano structured materials, we perform deformation tests for nanocrystal and polymer models using molecular dynamics simulations. It can be concluded that the difficulties for structural transitions of local lattice defects, e.g., structural changes from line defects to plane defects, strongly affect the generation of local plastic deformations and its propagations.出典：研究課題「結晶・非晶質構造体の局所塑性変形の連結・伝ぱメカニズムに関する原子・分子論的研究」課題番号19760061
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-19760061/19760061seika/）を加工して作成金沢大学理工研究域機械工学系research repor
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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