1,720,968 research outputs found
Direct Mass Measurements of Neutron-Deficient Lanthanides for Nuclear Structure Studies at the Proton Dripline
Full text linkExperimental and theoretical studies of exotic nuclei, i.e., very short-lived nuclei far away from the valley of stability in the chart of nuclides, present a unique and important way to gain general understanding of the atomic nucleus and the governing interactions of its constituents. There is an intriguing interplay of strong, weak, and Coulomb interaction, yet the contributions from all fundamental forces (except gravitation) are integrated in the mass of a nucleus. This makes the mass one of its key properties, allowing to study nuclear structure and basic interactions. Studying exotic nuclei is challenging since they need to be produced first, they are short-lived (many of them have half-lives of only few seconds or even far below), they can only be produced in small quantities, and often the interesting ones are accompanied by a full zoo of other, less exotic and more abundantly produced nuclei. Therefore, powerful separation methods are needed to deal with huge amounts of non-interesting 'by-products' and simultaneously obtain reliable results even for the few nuclei of interest. Moreover, the goal to extract information on basic interactions and nuclear structure requires high accuracies despite low statistics. In this work, improvements and measurements have been implemented and performed at two experiments at different accelerator facilities. In both experiments, a Multiple-Reflection Time-of-Flight Mass-Spectrometer (MR-TOF-MS), which has been build at Gießen University, is used. At the FRS Ion Catcher (FRS-IC) at GSI, Darmstadt, the improvements enabled unprecedented mass accuracies; at TRIUMF’s Ion Trap for Atomic and Nuclear sciences (TITAN) at TRIUMF, Vancouver, Canada, a novel method for mass separation was used to facilitate measurement with previously unknown nuclei. Within these measurements, a new isotope was discovered. This is the first discovery of a new isotope using a time-of-flight mass spectrometer. This demonstrates the advance of the frontier in mass measurements of exotic nuclei and the understanding of nuclear structure at the extremes. At the FRS-IC, several hardware and software elements have been upgraded. The new slow control system at the FRS-IC is running stable and ready to control, monitor and log existing and also various planned extensions of the detector setup. A procedure for systematically tuning the ion optics to unprecedented mass resolving powers R = m/∆m = 1 000 000 and beyond has been established. This enabled the measurement of several exotic nuclei with mass numbers around A = 70 close to the N = Z line. Among these measurements was the first direct mass measurements of 69-As, with only 10 events and with reduced uncertainty compared to the average of the previous indirect measurements. For one measued molecule, an accuracy of δm/m = 1.7 × 10e-8 was reached, which is the highest accuracy for MR-TOF-MS world-wide. The techniques applied at the FRS-IC have since been used at the TITAN MR-TOF-MS as well, also there leading to improved mass resolving powers. For TITAN, mass-selective re-trapping was characterized and for the first time used with exotic nuclei, enabling the direct measurement of 2 new and 2 improved ground state masses for neutron deficient Yb isotopes, the first measurement of the excitation energy of the Jπ = 11/2− isomeric state in 151-Yb and the indirect determination of 11 more ground state masses connected via α- and p-decays to two of the newly measured masses. The measurement of the mass of 150-Yb is at the same time the first discovery of a new isotope with an MR-TOF-MS. The direct ground state mass measurements of the Yb isotopes and the subsequent determination of masses of Lu isotopes have established the N = 82 neutron shell closure farthest from the valley of β-stability with unmodified shell gap; the shell structure far from the valley of stability is a key question of modern nuclear physics. The measurement of the Jπ = 11/2− isomeric state excitation energy extends a series of constant excitation energies in these odd N = 81 states, which could now be explained by deformation of the ground and isomeric states in collaboration with theorists employing state-of-the-art nuclear mean field
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
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
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