1,720,975 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Superfluidity of liquid ^3He in aerogel
No full textエアロジェル中のヘリウム3の超流動を超音波測定により研究する事を計画し、以下の項目について成果を得た。
1.超音波測定システムの作製
超音波測定装置として、本研究費の備品費より購入した超音波レシーバを用い、精密な音速測定を可能にする直交検波を行うことができるシステムを構築した。超音波パルス発生装置には東京工業大学の備品を利用していたため、研究代表者の金沢大学転任に伴い、新しい測定装置の製作が行われ測定系が構築された。
2.エアロジェル-ヘリウム4複合系の音波モードの観測
超音波測定装置の性能評価とエアロジェル中の音波の伝播の概要を理解するために、液体ヘリウム4中に実際に合成したエアロジェルを浸し10MHzの周波数において超音波測定の実験を行った。その結果、エアロジェル中の液体ヘリウムを伝播する超音波は、エアロジェルによる散乱によりかなり大きな減衰を示すことが明らかになった。また、ヘリウムのみの場合に見られるフォノンとロトンの散乱による吸収ピークはエアロジェル中では発見されなかった。重要な発見として、音波の伝播速度がエアロジエルの密度に大きく依存することが観測された。この系ではエアロジェルと液体ヘリウムの両者が結合した音波のモードの存在が予想され、我々の実験では音波モードのうち速い音速を持つモードの観測に超流動と常流動の両相で成功した。この研究の成果はPhysical Bに掲載された。
3.核断熱冷凍装置の製作
平成11年4月より、研究代表者の松本が東京工業大学より金沢大学に転任した。このため、ヘリウム3の超流動を実現するために必要な核断熱冷凍装置を新しく製作しなくてはならなかった。平成11〜12年度とこれに取り組んできた結果装置の基本的部分については完成を見た。さらにヘリウム3の超流動転移温度である1mK以下の温度に到達するように装置の調整が行われた。Ultrasound measurement has been used to study super fluidity of liquid He in aerogel. We obtained the following results.
1. Ultrasound spectrometer Ultrasound spectrometer using Phase Sensitive Detection has been made with a receiver purchased by this grant. This system enables to measure sound velocity sensitively. Main researcher, Matsumoto has moved to Kanazawa University so that we had to make a new system and has completed it.
2. Complex sound mode in aerogel-He4 system For the test of the system, 10 MHz Ultrasound measurement has been done with liquid He4. We have observed complex sound mode in this system due to coupled motion between aerogel and liquid. An important result is that the sound velocity of this mode is extremely sensitive to the aerogel density. Theoretical analysis predicts the two complex sound modes and the observed mode has been shown to correspond to the fast mode. This is the first that this mode was observed in both normal and super fluid phase. Large absorption coefficient and no absorption peak due to Roton-Phonon interaction have been observed. These results have been published in Pysica B (as shown in the reference).
3. Nuclear demagnetization refrigerator The main researcher, Matsumoto has move to Kanazawa University from Tokyo Institute of Technology in April 2000. We could not use nuclear demagnetizatio refrigerator in Tokyo Institute of Technology any more so that a new refrigerator had to be constructed at Kanazawa University. We have been trying to build nuclear refrigerator and main components have been completed. We continue improving it to achieve temperature below 1 mK which is necessary to study super fluidity of liquid He3.研究課題/領域番号:10640335, 研究期間(年度):1998-2000出典：「エアロジェル中の液体ヘリウム3の超流動」研究成果報告書 課題番号10640335
(KAKEN：科学研究費助成事業データベース（国立情報学研究所）)
本文データは著者版報告書より作成research repor
Variations on the Author
No full text“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
No full textWe 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
Quantum phase transition of liquid helium in aerogel
No full text1997年研究代表者の松本はエアロジェル中の液体ヘリウム3の系において、超流動-常流動転移に量子相転移が起こることを見いだした。また、孔径の小さな多孔質ガラス中の液体ヘリウム4も超流動-常流動転移に量子相転移を起こすという報告があり、多孔質体中のヘリウムは3,4どちらの同位元素も興味深い性質を示す。我々はこの系の状態を調べる方法として、超音波を用い、液体ヘリウム3と4の両者について、量子相転移や量子臨界状態の解明を目指して研究を行った。
1.エアロジェル中のヘリウム4の実験
ヘリウム4の相図を様々な空孔率のエアロジェルについて確立した。空孔率92%以上のエアロジェル中では液体ヘリウム4は超流動転移は抑制されるが量子相転移を示さないことが分かった。また、ヘリウムの結晶がエアロジェル中で生成される過程や、固体および固体・液体界面の音響的性質を観測し、エアロジェルが結晶成長や固体中の空孔や転位に及ぼす効果を明らかにした。さらに、超流動相において、特異な超音波減衰の増大を観測し、これと新たな集団励起モードとの関係について国際会議等で発表した。
2.エアロジェル中の液体ヘリウム3の実験
超低温領域での実験を行うために核断熱冷凍機の整備を進め、大型の核断熱冷凍機が完成した。ヘリウムの試料セルの作製については、低温部での圧力その場観測が可能な超音波実験セルを作製した。特に、バルクヘリウムとの違いを明確にするために、ジェルとバルクの両方の試料を同じでセルで観測出来るようにした。現在、このセルを用いた実験が進行中である。冷凍機のトラブルのため研究期間内に十分なデータの蓄積は行えなかったが、現在も実験が継続しており、新しいデータが得られつつある。すでに、純粋な液体ヘリウム3とは全く異なる超音波吸収の温度変化を示すことなどが明らかになりつつある。We have presented evidence for quantum phase transition (QPT) on superfluid phase transition of helium 3 in 98% aerogel in 1997. However, the details of the QPT are not known so far. We studied the QPT of helium in aerogel for both helium 3 and 4 using ultrasound technique.
1. helium 4 and aerogel system
QPT is reported for helium 4 in porous glass with small pore. We have studied superfluid transition of helium 4 in aerogel with porosity between 92 and 97 %. The transition was suppressed by aerogel. We have made the phase diagram for this system. However, QPT was not observed in aerogel. We have observed many interesting phenomena in this research. For example, anomalous sound attenuation was observed with 97 % porous aerogel around 1.7 K. This result suggested possibility of mode conversion between first, second sound in superfluid and aerogel sound mode in this composite system.
Solidification of helium in aerogel was studied. Sound transmission trough the solid-liquid interface has been observed. Our experiment shows the crystal growth is suppressed by silica strands of aerogel.
2. helium3 and aerogel system
A nuclear demagnetizing refrigerator has been constructed for this experiment. The sound cell has acoustic cavities with aerogel and bulk liquid for comparison. The signal with aerogel has been observed using longitudinal ultrasound at 6 MHz. Because of the trouble of refrigerator, only preliminary experimental data was obtained. The experiment is ongoing.研究課題/領域番号:16540312, 研究期間(年度):2004-2006出典：「エアロジェル中の液体ヘリウムの量子相転移」研究成果報告書 課題番号16540312
(KAKEN：科学研究費助成事業データベース（国立情報学研究所）)
本文データは著者版報告書より作成research repor
Hydrogen magnetic refrigeration using new magnetic materials with multiple phase transition
No full text磁気冷凍法による高効率な水素液化の実現に、多重相転移を持つ磁性体を利用し、広い温度範囲で磁気熱量効果を増大できる可能性がある。本研究では、(ErDy)NiAl系, (Er,Dy)Al2系, Er(Co,Ni)2系, Er(Co,Cu)2などで希土類、遷移金属の置換でエントロピー変化を制御した物質の合成を行った。磁化、磁場中比熱、断熱消磁測定などにより磁気熱量効果を評価し、実用となる磁気冷凍用磁性材料の研究を進めた。これまでの単純な常磁性-強磁性・反強磁性転移だけでないエントロピー制御性を持つ磁性体の特性を明らかにした。また、金属間化合物以外にも硫化物、酸化物などの磁性体の特性を明らかにした。Magnetic refrigeration method makes use of the magnetocaloric effect (MCE) where some magnetic materials exhaust or absorb heat by applying or removing external magnetic fields. MCE is induced by the internal magnetic entropy change of magnetic material, thus magnetic refrigeration can operate an ideal cycle like Carnot.
In this research, we investigated new magnetic materials that will be useful for hydrogen magnetic refrigeration. It is possible to control temperature and magnetic field dependence of the MCE using magnetic materials with multiple transitions. Magnetic materials of intermetallic compounds such as (ErDy)NiAl, (Er,Dy)Al2, Er(Co,Ni)2, Er(Co,Cu)2 were synthesized. Magnetic and thermal properties of those compounds were measured in order to evaluated MCE. MCE results for oxides, sulfide that have rare-earth elements were also studied as useful materials.研究課題/領域番号:26420720, 研究期間(年度):2014-04-01 - 2017-03-31出典：「多重相転移磁気熱量効果を利用した新規磁性体による高効率水素磁気冷凍の研究」研究成果報告書 課題番号26420720
（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-26420720/26420720seika/）を加工して作成金沢大学理工研究域数物科学系research repor
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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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