1,720,965 research outputs found
Immobilization and Application of Lipase Enzyme in Mesoporous SBA-15 Molecular Sieve
No full text本論文研究目的為將解脂酵素（lipase）固定於介孔材料載體，並檢測其催化效果，重複使用效率及熱穩定性。所選用的載體為利用兩性高分子EO20PO70EO20（P123）界面活性劑為模版與tetraethoxysilane（TEOS）為矽源，在酸性條件下合成之介孔SBA-15分子篩以及表面修飾有機官能基之SBA-15，包含修飾單一胺基或苯基以及同時修飾以上兩種官能基之SBA-15。其中，含胺基之SBA-15比較了兩種製備方法，分別是以嫁接法或是以TEOS與3-aminopropyl- triethoxysilane （APTES）共沉澱所合成，其它含官能基之SBA-15則由TEOS、APTES與phenyltriethoxysilane（PTES）等矽源以共沉澱法合成，接著將介孔材料加入酵素的水溶液中以進行酵素的吸附。研究發現，若改變吸附酵素環境之pH值，無論是哪種載體，最大的吸附量皆於酵素等電點（約pH 4.7）附近，而純矽之SBA-15及含有苯基之SBA-15對於解脂酵素有較大負載量，推測酵素與載體之間的作用力來自於庫倫力及疏水作用力。
酵素吸附於介孔分子篩後，可再進行後處理，嘗試以不同方式固定酵素：一為將吸附了酵素的SBA-15，另外再以PTES進行後處理，此為包覆法；另一為將吸附了酵素的含有苯基之SBA-15，再以戊二醛進行交聯反應(cross-linking)。最後利用三乙酸甘油酯(triacetin)的水解反應來測試各種已固定化酵素之活性，並對其重複使用之效率及熱穩定性進行試驗。第一章 緒論 1
1.1 界面活性劑簡介 1
1.2 介孔材料簡介 4
1.3 酵素固定簡介 7
1.4 解脂酵素簡介 12
1.5 研究動機 14
第二章 實驗部份 15
2.1 化學藥品 15
2.2 介孔分子篩的製備 16
2.3 樣品之鑑定與分析 19
2.4 將解脂酵素(lipase)固定於介孔材料(Immobilization) 25
2.5 解脂酵素固定於介孔材料之後修飾 27
2.6 酵素活性測試 28
第三章 結果與討論 32
3.1 介孔材料結構鑑定與分析 32
3.2 酵素固定於介孔材料 48
3.2.1 改變吸附pH值 48
3.2.2 改變酵素濃度 51
3.2.3 改變吸附時間 53
3.3 介孔材料吸附酵素後之鑑定與分析 55
3.3.1 以物理吸附法固定酵素 55
3.3.2 後修飾 64
3.4 酵素活性測試 68
第四章 結論 75
參考文獻 7
A Study of The Aerodynamics of Butterfly-type Flapping Wing
No full text因應用途及任務的需要，無人飛行器(UAVs)的尺寸正往逐漸縮小的方向發展。隨著飛行器尺寸的縮小其翅膀的展弦比也隨之變小，若繼續沿用傳統UAVs所使用的固定翼來產生氣動力，將不足以支撐飛行器的重量。在自然界中，昆蟲的翅膀具有低展弦比卻能在空中自在飛行，其生理特徵、運動模式等等，都是開發微型飛行器(MAVs)者可以師法的對象。本研究選定燕尾蝶為研究對象，透過CFD商業軟體ANSYS Fluent探討燕尾蝶型翼在相同的飛行速度時，於不同拍撲頻率及不同攻角下之氣動力性質，並探討燕尾翼構造對於拍撲飛行流場之影響。此外，我們也設計一具相同展弦比之對稱長平板翼，將其氣動力特性與蝶型翼之氣動力特性進行比較，以進一步了解蝶型翼之優點。研究結果發現：燕尾蝶型翼以滑翔飛行時，其升力先隨著攻角上升逐漸增加，於攻角40度時有最大值，若攻角角度繼續增加則升力逐漸下降；而阻力則隨著攻角上升呈現單調漸增的趨勢；於攻角10度時有最大的升阻比。於拍撲飛行時，一週期內之平均升力、阻力及升阻比隨攻角變化的趨勢與滑翔飛行時雷同，惟其值隨拍撲頻率的增加而增大；比較蝶型翼與對稱長平板翼流場之俯仰力矩，發現因為燕尾蝶型具有前掠型的翼前緣，於下拍行程時，作用於翅膀的流場可對身體幾何中心產生一有助於提升攻角之力矩，可能導致升力及阻力的增加；反之，於上拍行程時，攻角角度受到反向力矩作用於身體之結果而降低，升力及阻力也因而減少。此力矩影響攻角大小的現象與前人的實驗觀察有相似之處。透過三維流線分布圖，發現燕尾翼於高頻拍撲飛行之下拍行程中，無論為高攻角或低攻角飛行，於燕尾處會形成較結實的流場結構，推測應有助於流場的穩定。Corresponding to the requirements of applications and tasks, the size of the unmanned aerial vehicles (UAVs) is tending smaller and smaller. Following the size reduce, the aspect ratio of the UAV wings reduces as well. Consequently, the common fixed-wings are no longer capable of providing enough aerodynamic forces against the gravity. In the nature, insects’ wings have low aspect ratios, but they fly freely in the air. Their physical characteristics and movement patterns must have implications which are useful for developing micro UAVs. This study aimed at the flow fields induced by a swallowtail butterfly in use of the software “ANSYS Fluent.” Parameters such as the flapping frequency, the angle of attack, the wing shape, and the swallowtail effect were explored. The simulation results show: when a swallowtail butterfly-type wing is in gliding, its lift force increases with the angle of attack first but decreases later, peaking at an angle of 40˚. On the other hand, the drag force increases monotonically. Consequently, the lift-drag ratio has its maximum value when the angle of attack is 10˚. The flapping flight has similar variation trends in the average lift force, drag force and the lift-drag ratio to the gliding flight but the magnitudes increase with the flapping frequency. Furthermore, unlike the long flat-panel wing, the butterfly-type wing can seemingly produce a positive pitch moment to rotate its body and consequently increase the angle of attack during the downstroke motion by taking advantage of its forward-swept leading edge. A negative pitch moment is generated during the upstroke motion the other way round. Similar observation had been reported in the literature. Through the 3D-streamline visualizations, it was also found that the swallowtail can help building some solid flow structures in the neighborhood during the downstroke motion when the flapping frequency is high, regardless of the angle of attack. It is believed that these structures are related to the flow field stability
Natural History and Women''s Education: Charlotte Turner Smith and John Ruskin
No full text本論文旨在以夏洛特‧史密斯（1749-1806）與約翰‧拉斯金（1819-1900）之
作品為例，探討十八世紀末至十九世紀間英國「自然史」與「女性教育」之互動。
自然史起源古希臘羅馬時期，本為研究人與自然關係之綜合型學科，其早期
綜合科學與人文之特性，使學者在書寫間可抒發其政治理念；在十八世紀末至十
九世紀的英國女性教育相關辯論正興之時，自然史即為其提供良好的平台。自然
史發展後受大英帝國海外擴張影響，轉變為一龐大、專業化、分工精細的自然科
學系統，也失去了其哲學與倫理學之色彩；其時女性教育便成為傳統自然史學者
再興其人文特色之途徑。
本論文自史密斯之《詩歌概論對話錄》（1804）與拉斯金之《塵土的倫理》（1865）著手，研究兩自然史與女性教育之兩種互動模式。身為以出版養家糊口的女作家，史密斯於《詩歌概論對話錄》，借自然史之人文特色教導女孩詩學、引導女性關注社會、經濟議題，將女性引領往公領域。為物質化科學憂心的拉斯金，則在《塵土的倫理》中運用女孩與水晶之譬喻，展現人類社會與地質環境之相似性，借女性教育論述對科學研究再人文化之期許。兩部作品出版時間相隔六十年的作品，
呈現了自然史與女性教育的兩種關係。This thesis delineates the convoluted development of natural history and women’s education in the eighteenth- and nineteenth-century Britain, with the focus on the contributions by Charlotte Turner Smith (1749-1806) and John Ruskin (1819-1900).
Natural history, an ancient study rooted in Greco-Roman time, has been refreshed by the expansion of the British Empire and has become a dominant science in the eighteenth and nineteenth centuries. As an academic discipline dealing with various aspects of nature and humans, the study of natural history became politically charged. Its existence created a platform for debatable issues, including women’s education, which was a popular topic tightly connected to natural history. As the empire expanded, natural history was divided into different disciplines and professionalized, and had lost its metaphysical characteristics. Women’s education became the platform on which scholars could consolidate the metaphysical natural history.
Suggesting that natural history empowered women’s education, and that women’s education could also be used to revive natural history, this thesis focuses on two educational works for girls, Smith’s Conversations Introducing Poetry (1804) and Ruskin’s The Ethics of the Dust (1865). Being a woman who has to support herself and her family with publications, Smith educates girls to approach poetics, economy and social criticism via the metaphysical natural history, and leads them to the observation of the public sphere. Worried by the materializing science, Ruskin displays the similarity between human society and geological environment and tries to revive metaphysical natural history through the analogy of girls and crystals. The two works shows related yet different views on the relationship between natural history and women’s education.Acknowledgements i
Abstract iii
Table of Contents v
Introduction 1
Chapter One
Natural History and Women’s Education from Late Eighteenth Century to Mid-Nineteenth Century 13
Chapter Two
Natural History and Women’s Education in Charlotte Turner Smith’s Conversations Introducing Poetry 37
Chapter Three
Confirming Authority: Geology and Female Education in John Ruskin’s The Ethics of the Dust 64
Conclusion 86
Works Cited 8
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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