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Study of tunable lens based on dielectric elastomer actuator
No full text隨著科技的蓬勃發展，各式元件都朝著低耗能及輕薄短小的趨勢發展。現今
市面上所販售的變焦機制，係利用多個透鏡所組成的透鏡組，並藉由線性馬達及
齒輪組來改變各個透鏡之間的間距，以達到變焦的效果。但是此機制所需求的裝
置空間較大，為了縮減佔有的空間，近年來，便有人發展出了可變焦的透鏡。本
論文運用了介電致動高分子材料來製作可變焦的透鏡，由於介電致動高分子材料
具有良好的力學性質、方便製作、低成本並且不受溫濕度變化的特性。介電致動
器係由兩片平整的電極和一層介電高分子材料所組成，結構就像三明治一樣。它
的驅動特性，會受驅動電壓大小及其幾何尺寸上的限制影響；隨著施加的電壓上
升，因其所受的靜電力增加而使得上下兩電極逐漸靠攏並擠壓中間的介電高分子
材料。然而，在邊界受限制的情況下，被擠壓的介電高分子材料會產生翹曲的情
形，本論文運用此結果作為可變焦透鏡的工作原理。在製程方面，本論文用懸浮
的方式來製作超薄且均勻的聚二甲基矽氧烷(PDMS)薄膜並以食鹽水溶液來作為透
明電極使用。本論文中使用了兩種常見的焦距量測方式來測量可變焦的焦距，實
驗結果顯示本論文中所製作的可變焦透鏡可達到3 mm 的變焦範圍在電壓從0 施加
到900 V 的範圍內。從電流的量測結果可以看出，此介電致動器的能量消耗主要
是用於每一次的變焦，並且只需要持續提供很微量的能量來維持變形量。在600 V
的情況下，電流很穩定，但是在600 V 以上的電流圖就有不規則的突波產生，經
觀察並推測，在大變形量下，金電極表面會有些微的裂紋產生。本論文最後將此
可變焦透鏡安裝於市售筆記型電腦的視訊鏡頭，並得到良好的影像輸出。With the rapid development of science and technology, all kinds of devices are in the trend of becoming thinner, lighter, smaller, and having lower power consumption.
Current mechanism of commercial tunable lenses utilizes multiple lenses of different focal lengths to form a sophisticated optical system. With the linear motor and gears, the focal length can be tuned by changing the spacing between lenses. However, this mechanism needs a larger System volume. In recent years, many efforts have been taken
to develop tunable lens to reduce the system volume. In this thesis, we present a tunable lens which is driven by dielectric elastomer actuator (DEA). DEA has good mechanical
properties, low cost, low power consumption, and is less affected by temperature and humidity. DEA is formed by a layer of dielectric elastomer sandwiched by two
complaint electrodes. The operating characteristics of DEA are dominated by the applied voltage and the geometric configuration. With increasing applied voltage, which
increases electrostatic force, the complaint electrodes of the actuator gradually become closer to each other and the dielectric elastomer is squeezed. Under boundary restrictions, extruded dielectric elastomer will be buckled. This thesis uses this result on tunable lens system. In the process, the release method is used to fabricate thin and
uniform polydimethylsiloxane (PDMS) membrane and NaCl solution is used as a transparent electrode. In the experiments, we used two common methods to measure the focal length of our tunable lens system. The experimental results show that the focal length can be tuned by 3 mm by applying voltage from 0 V to 900 V. From the current measurement results, the energy is mainly consumed at the moment of DEA deformation. It only needs little energy to maintain the deformation. When the applied voltage is below 600 V, the current is stable. However, the current has irregular impulses when the applied voltage is over 600 V. By observation and speculation, the gold electrode surface has some defects in large deformation. Finally, we setup our
tunable lens on the webcam of a commercial notebook computer to function and capture clear images
以定電位法及循環電位掃描法對各種不同電極上氫-氫離子的電化學反應及其均勻電池剩餘電壓的研究
No full text[[abstract]]本研究是將二支電極插入磷酸溶液中，在一大氣壓氫氣覆蓋下，構成一密閉均勻系電
池，結果發現黃金、銀、銅電極與白金或石墨電極所構成的電池有相當大的剩余電壓
，而鈀電極或石墨電極與白金電極所構成的電池其剩余電壓為零。
同時又利用電極動力學的方法研究黃金、白金、鈀、銀、銅、石墨等電極上氫一氫離
子氧化還原的電化學反應從所得到的循環電位圖及極化曲線圖顯示氫一氫離子氧化還
原的電化學反應在白金電極上的可逆性甚佳，而在金、銀、銅、電極上的反應較差，
從電極動力學的研究結果可以解釋均勻電池剩余電壓的現象。
不同惰性電極對密閉均勻電池之剩餘電壓及其平衡速率之影響
No full text[[abstract]]本研究是把兩支或三支惰性電極如Ｐt ，Ｐd ，Ｃ，Ａu 浸入磷酸或氫氧化鈉溶液
，在一大氣壓氫氣下，構成密閉均勻電池，經由放電來觀察其趨近於平衡的速率及
其剩餘電壓。結果發現Ａu 與Ｃ或Ｐt 電極所構成之電池大都有相當大的剩餘電壓
，而Ｐt 與Ｐd 或Ｃ電極所構成的電池，其剩餘電壓接近零，關於剩餘電壓不為零
的現象，可以用電極之不可逆性及其對氫分子的吸著力之不同加以解釋。本實驗也
發現氧對白金以及石墨電極的電位有相當的影響。
不可逆氫電極及其中毒之研究
No full text[[abstract]]本文是繼續以前之成果, 研究黃金、汞、鉛電極與白金電極所構成之均勻電池，發現
都有相當大的乘餘電壓，尤其以汞為電極，得到很穩定的剩餘電壓，至今此現象尚無
法解釋，於本文中吾人提出媒體永流模型，此模型能夠圓滿解釋這些均勻電池之電壓
及電流悄不消失現象。
為了增加均勻電池之電流，本研究亦製作大電極之碳一鉛電池，並加入白金酸，發現
有增加電流的效果，其電流經三個月仍然保持穩定之電流，本文亦用循環電位法研究
黃金電極、汞電極及白金電極被毒化之現象。
新聚合方法- 電解產生氧化還原開始劑之間接電引發聚合研究
No full text[[abstract]]本實驗利用FeCl ，CrCl ，CH NH •HC1及HC1•NH NH •NH •NC1等為電解質，溶
於水或有機溶劑，在小電解槽內，陽極室產生氯溶液做為氧化劑，在陰極室產生還
原劑，做為redox initiator，發現利用CH NH •HC1 ，HC1•NH ，HC1為電解質，
而得之redox initiator 對於MMA 聚合產率比較高，但用FeCl ，CrCl 為電解質，
對MMA 之聚合產率較低。此外，水與甲醇對聚合率之影響亦在本文中研究。
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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
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