1,721,322 research outputs found
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
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
Studies on poly (ethylene terephthalate)(PET) surface modification and enhancement of the interfacial fracture toughness by cold plasma techlonogy
No full text本研究是利用低溫電漿技術對高分子聚對苯二甲酸乙二酯(PET)進行表面改質，而經過不同程度氮氣電漿改質後之PET，藉由化學能譜儀(XPS)進行表面分析及與水接觸角測試的親水性實驗；經過氮氣電漿處理之PET表面會產生含氮之官能基而使表面接觸角下降，再經由對細微XPS圖譜分析可知PET表面氮元素植入比率會隨著電漿處理程度而增加，最多可達8%。另外，利用另一高分子材料PSMA(poly styrene-co-maleic anhydride)與電漿處理後之PET進行化學反應接著之研究，經過電漿處理後之PET表面生成之amine之官能基會與PSMA中maleic anhydride作用產生imide之共價鍵結，對於不同程度之電漿處理PET各樣品，在不同熱處理溫度下進行此接合反應，再利用非對稱雙懸臂界面接著測量法(ADBC)作為測量兩材料界面強度之儀器，可知在熱處理溫度為150℃時有最佳之界面加強效果產生，界面接著強度可由未處理前約3J/m2增強至超過100J/m2。
利用XPS與SEM分析破壞界面，可以得知在不同界面接著強度下之破壞機制，在溫度為150℃時在電漿處理時間超過150sec後，由於兩高分子界面強度大於PET材料本身之層狀結構破壞強度，故破壞之破裂點會延伸至PET材料內部;而在反應溫度過高時(160℃)，界面強度反而下降是因為PSMA質傳過快而在界面形成一機械強度較弱之另一界面之緣故。
最後探討了界面接著強度與areal chain density(Σ)之關係後可知，在Σ值較小時，界面強度值(Gc)與Σ2成線性關係；當Gc值超過100J/m2後，破壞機制轉變至材料內部破裂，Gc值故不再隨著Σ值上升而增大。Nitrogen plasma caused ion implantation and then carried out surface modification on Poly (ethylene terephthalate)(PET) efficie- ntly. With the increasing of plasma treatment time, water contact angle of treated-PET surface would decrease, finally reached a stable value, 25degree. By X-ray photoelectron spectrometer (XPS) analy- sis, atomic nitrogen content of plasma treated PET by ion implantation and bonding condition can be obtained. Furthermore, the interfacial fracture toughness (Gc) between ( poly styrene–co- maleic anhydride) (PSMA) and plasma treated-PET was had investigated.
Amine groups formed by plasma modification on the PET surface can reacts with styrene maleic anhydride (SMA) in bulk PSMA, forming imide covalent bonds to enhance interfacial fracture toughness between PET/PSMA. In our case, when annealing temperature at 150℃, the PET/PSMA is too strong to cause crack-tip propagated into PET side, the Gc values could be enhanced over 100J/m2 for long plasma treatment time. Otherwise, the diffusion rate of PSMA is too fast at annealing temperature at 160℃, causing a new weak interface occurred, and then crack-tip would propagate into PSMA side, Gc value become lower than condition 150℃. Fracture mechanisms are verified by XPS and SEM analysis of fractured PET and PSMA surface, and the results coincide with our explanation.
In our case, there are two mechanisms of PET/PSMA interface fracture. When areal chain density (Σ) on the interface is lower than 0.05/nm2, the interfacial fracture toughness (Gc) is proportional to Σ2. And at areal chain density larger than 0.05/nm2 region, the interfacial fracture toughness is independent to areal chain density, because the fracture happened in PET side.中文摘要..............................................I
Abstract............................................III
目錄.................................................IV
表索引.............................................VIII
圖索引...............................................IX
第一章 緒論 ..........................................1
第二章 文獻回顧 ......................................4
2.1 電漿改質原理 .................................4
2.1.1電漿簡介 ................................4
2.1.2電漿氣體基本反應 .........................5
2.1.3電漿產生方式 .............................6
2.2高分子界面增強理論............................11
2.2.1利用共聚物增強界面接著.................. 12
2.2.2接枝反應增強界面接著.................... 14
2.2.3電漿改質增強表面接著.................... 15
第三章 實驗部份.....................................18
3.1實驗目的 ................................... 18
3.2實驗流程圖................................... 19
3.3 材料與藥品.................................. 20
3.4 儀器設備 .................................. 21
3.5實驗步驟..................................... 23
第四章 研究結果與討論 ............................. 28
4.1電漿改質後PET表面性質....................... 28
4.1.1表面親水性質........................... 28
4.1.2 以XPS分析電漿處理後PET表面............ 29
4.2 反應性接著增進界面強度...................... 33
4.2.1 兩材料厚度比例對界面強度之影響.........33
4.2.2 熱處理時間對於界面強度之影響...........34
4.2.3 熱處理溫度對界面接著強度影響...........35
4.3 破壞面之表面分析.............................37
4.3.1 破壞面XPS表面分析......................37
4.3.2 掃瞄式電子顯微鏡(SEM)分析結果..........38
第五章 結論………………………………………………………41
第六章 參考文獻......................................4
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
Laser halo measurements of solid–liquid two phase flows
No full text本論文使用一個內含輸送帶的水槽和新穎的量測技術來實驗高濃度固液二相流之流場分析。該水槽可用來產生穩定之均勻自由液面，並使其在控制的條件下流動。在流體內的粒子濃度和運動速度，透過透明的固液二相流(使用折射率相同之液體與顆粒)來獲得，並且使用一條雷射切頁照亮橫斷面。 當顆粒穿過雷射切頁時，球形的粒子會產生一亮環，利用此現象來量測濃度和流速分佈。 這些量測值可用來分析粒子分布的濃度，剪應變率和層與層間剪力的關連性。Flows of concentrated solid-liquid mixtures are studied experimentally using a moving belt flume and novel measurement techniques. The flume is used to produce steady uniform free-surface flows under controlled conditions. Measurements of particle concentration and motions inside the mixture are obtained by making the mixture transparent (using refractive index matching), and illuminating a cross section using a laser light sheet. As they cross the light sheet, the spherical particles produce bright halos, which can be interpreted to obtain concentration and velocity measurements. These measurements are analyzed to examine relationships between solid concentration, shear rate, and inter-layer stresses.誌謝 ii
摘要 iii
Abstract iv
Contents v
Figure list vi
Table List ix
1. Introduction 1
2. Experimental facility 4
2.1 Flume 5
2.2 Liquid and solid materials 6
2.3 Drums and conveyer belt 8
2.4 Liquid recirculation system 10
2.5 Laser illumination system 12
2.6 Imaging system 14
3. Image processing 16
3.1 Image rectification 17
3.2 The X-ray cross section 22
3.3 Time Slice 23
3.4 Particle capture 25
3.5 Concentration profile 30
3.6 Velocity profile 31
4. Results and analysis 32
4.1 Definitions 33
4.2 Experimental conditions 35
4.3 Case N15Q30U1 37
4.4 Case N15Q30U5 39
4.5 Case N15Q30U9 41
4.6 Case N25Q30U1 43
4.7 Case N25Q30U5 45
4.8 Case N25Q30U9 47
4.9 Comparison 49
5. Conclusions and further work 59
References 6
- …
