1,720,954 research outputs found
English Thesis Title: Study of CE/MS in Chiral Separation Using Low Concentration and High Concentration Nonvolatile Cyclodextrin Buffer
No full text目前解決低濃度帶電荷環糊精修飾毛細電泳 (CD-EKC) 銜接電灑法質譜 (ESI-MS) 的問題，主要是利用counter-migration分離技術，使環糊精對於分析物訊號的抑制可被減緩。然而一般商業化毛細電泳質譜的介面，利用 counter-migration 分離技術，因環糊精無法由質譜端持續補充而導致分離的解析度會下降。本研究利用實驗室先前已開發的液體結合-低流速鞘流介面 (liquid-junction/low-flow interface)，在液體結合槽中填入分離管所需的緩衝溶液，使分離管內的環糊精可藉由液體結合槽中的緩衝溶液來補充，而得以進行連續多次毛細電泳質譜的分析，也維持一定的分離效率。
另一方面，許多對掌異構物的分離必須使用高濃度的環糊精才可達到，此分離技術為carrier-mode separation。然而此分離技術銜接上電灑法質譜需改善高濃度環糊精對於分析物訊號所造成嚴重抑制的問題，故本研究利用液體結合-低流速鞘流介面，施加正向電場於銜接管中，使負電荷環糊精可以藉由電場作用停留於液體結合槽中，且為了避免環糊精將分析物帶至液體結合槽中，必須在液體結合槽中添加有機相以降低環糊精與分析物之間的作用力，使得分析物可以藉由本身的電泳淌度與電滲透流往質譜端移動。此外利用塗佈聚乙烯醇毛細管 (polyvinyl alcohol-coated) 作為分離管，此分離管無電滲流，故可避免液體結合槽中的有機相隨著電滲流進入分離管，破壞分析物與環糊精之間的作用，而影響分離。此方法不僅維持原有高濃度環糊精良好分離效率，且成功解決環糊精造成的訊號抑制。The counter-migration technique has been reported to couple low concentration charged cyclodextrin electrokinetic chromatography with electrospray ionization mass spectrometry detection without suffering ion suppression effect. However, if this approach is adoped to couple charged cyclodextrin electrokinetic chromatography with commercial CE-MS interface, the resolution could be decreased due to the depletion of charged cyclodextrin zone . With the use of a liquid-junction/low flow interface, the charged cyclodextrin migrated from the liquid junction reservoir to the separation column continuously to maintain the separation efficiency.
However, certain enantioseparation operated under the condition that the higher concentration of cyclodextrin used to carry the analyte to achieve separation with negative polarity. A liquid-junction/low-flow interface was used to alleviate the ion separation by avoiding the entering of cyclodextrin into the ESI source. The charged cyclodextrin could be stayed in the liquid junction reservoir. Because of the higher interaction between the cyclodextrin and the analyte, the running buffer containing 20% methanol was added to the liquid junction reservoir to detach the cyclodextrin from the analyte. To avoid the entering of methanol into separation column during CD-EKC separation, a polyvinyl alcohol-coated column was used as the coating column. Both good chiral separation efficiency and low ion signal suppression could be achieved with this approach
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
- …
