1,722,332 research outputs found
Characterization and Reactivity of Mo₂C
No full textTwo types of Mo₂C have been investigated: polycrystalline β-Mo₂C and single crystal α-Mo₂C. The β-Mo₂C material was synthesized via a temperature-programmed method, and then characterized using x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), CO chemisorption, and N₂ physisorption. The catalytic activity of the β-Mo₂C was tested for cumene hydrogenation under high pressure conditions, and the effect of sulfur and oxygen poisons on cumene hydrogenation was also investigated.
As a complement to the work done on polycrystalline β-Mo₂C, UHV studies of single crystal α-Mo₂C were undertaken to provide fundamental information about a well-characterized Mo₂C surface. The (0001) surface of α-Mo₂C was investigated using XPS and low energy electron diffraction (LEED). It was found that an ion-bombarded surface could be prepared as either Mo-terminated or C-terminated by choosing either low annealing temperatures (~1000 K) or high annealing temperatures (~1500 K), respectively. CO and O₂ adsorption was also studied on α-Mo₂C (0001) using thermal desorption spectroscopy (TDS), XPS, Auger electron spectroscopy (AES), and LEED. Finally, thiophene adsorption was investigated on α-Mo₂C (0001).Ph. D
ФАЗОВІ РІВНОВАГИ В СИСТЕМІ Fe-Mo-C
Get PDF Fe-Mo-C alloys has been investigated using X-Ray and metallography methods. Phase composition and microstructure of this alloys has been determined . π and χ phases formation, as would be expected according to literature data, has not been observed. Assumption, concerning structure peculiarities of the Fe-Mo-C phase diagram, has been set up for the experimental data explanation. Методами рентгенографии и металлографии исследована сплавы тройной системы Fe-Mo-C. Определены их фазовый состав и микроструктура. Образование π и χ фаз, которое ожидалось на основании анализа литератур-ных данных, не наблюдалось. Для объяснения экспериментальных данных выдвинуто предположение об особенностях строения диаграммы состояния системы Fe-Mo-C. Методами рентгенографії і металографії досліджено сплави потрійної системи Fe-Mo-C. Визначено їх фазовий склад і мікроструктура. Утворення π та χ фаз, яке очікувалося на підставі аналізу літературних даних, не спостерігалося. Для пояснення експериментальних даних висунуто припущення щодо особливостей будови діаграми стану системи Fe-Mo-C
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
Исследование механизма газоабразивного изнашивания Fe-Cr-V-Mo-C покрытий
No full textВыпускная квалификационная работа – 104 с., 22 рисунка, 19 таблиц, 22 использованных источника, 1 приложение. Цель работы – провести сравнительный анализ износостойких свойств покрытий, полученных плазменной наплавкой порошка Пр-Х18ФНМ и покрытий, сформированных ручной дуговой наплавкой покрытыми электродами Т-590, а также исследовать механизм газоабразивного изнашивания Fe-Cr-V-Mo-C упрочняющих слоев. Для достижения поставленной цели были решены следующие задачи: проведен анализ материалов, используемых для восстановления деталей, работающих в условиях газоабразивного изнашивания. Проведены лабораторные и производственные испытания на газоабразивную износостойкость Fe-Cr-V-Mo-C покрытий, наплавленных электродами Т-590. Исследован механизм газоабразивного изнашивания Fe-Cr-V-Mo-C покрытий.Graduate qualifying work - 104, 22 figures, 19 tables, 22 sources used, the application 1.. Purpose - to conduct a comparative analysis of the wear-resistant properties of the coatings produced by plasma welding powder Ex-H18FNM and coatings formed manual arc welding with coated electrodes T-590, as well as to explore the mechanism of gas-abrasive wear of Fe-Cr-V-Mo-C reinforcing layers. To achieve this goal the following tasks were solved: the analysis of the materials used for the restoration of parts, working in conditions of gas-abrasive wear. The laboratory tests and industrial gas-abrasive wear resistance of Fe-Cr-V-Mo-C coatings deposited electrodes T-590. The mechanism of gas-abrasive wear of Fe-Cr-V-Mo-C coatings
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
Revealing the influence of Mo addition on interphase precipitation in Ti-bearing low carbon steels
No full textMo is widely used as an effective microalloying element to improve mechanical performance of interphase precipitation steels, but the precise role of Mo in interphase precipitation behavior is not fully understood. In this contribution, interphase precipitation behavior in a series of Ti-Mo-bearing low carbon steels is systematically studied, and the role of Mo in interphase precipitates and its coarsening behavior is revisited. It is found that (Ti, Mo)C precipitates instead of TiC are formed in the Mo-containing alloys, and the average site fraction of Mo in (Ti, Mo)C is almost independent of the bulk Mo content. Moreover, the number density of interphase precipitates can be substantially enhanced by a minor addition of Mo, albeit it does not further rise with increasing the bulk Mo content. This is because the Mo fraction in (Ti, Mo)C rather than the bulk Mo content governs the driving force for precipitation nucleation and the interfacial energy of the (Ti, Mo)C/α and (Ti, Mo)C/γ interfaces. In addition to the reduced interfacial energy, decrease of Ti trans-interface diffusivity has been identified as another key reason for the enhanced carbide coarsening resistance in Mo-containing alloys.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Novel Aerospace Material
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