1,721,557 research outputs found
Simulation of rail wheel axle bearing vibration due to local damages on outer races
No full textThis paper presents a dynamic model of bearings that simulates the vibration of rail wheel bearings due to local damages such as pits on the bearing outer race. The model, based on the multi-body simulation software RecurDyn, integrates the major parts of the functionalities according to the three-dimensional model and railway axle dynamic system. Three types of surface damages on the raceway of cylindrical roller bearings were designed and evaluated by the dynamic model developed in this study. The results show that the dynamic model can effectively simulate the influence of the damages on the bearing vibration under varied pit shape and size. Furthermore, the model can predict the level of bearing damage based on the peak value of bearing vibration in the frequency domai
Morphological studies and molecular data on a new marine ciliate, Apokeronopsis sinica n. sp. (Ciliophora: Urostylida), from the South China Sea
No full textLiu, Weiwei, Li, Jiqiu, Gao, Shan, Shao, Chen, Gong, Jun, Lin, Xiaofeng, Liu, Hongbin, Song, Weibo (2009): Morphological studies and molecular data on a new marine ciliate, Apokeronopsis sinica n. sp. (Ciliophora: Urostylida), from the South China Sea. Zootaxa 2005 (1): 57-66, DOI: 10.11646/zootaxa.2005.1.5, URL: http://dx.doi.org/10.11646/zootaxa.2005.1.
Long-term diffuse phosphorus pollution dynamics under the combined influence of land use and soil property variations
No full textAnalyses of the spatial-temporal distribution of diffuse pollution in agricultural regions are essential to the sustained management of water resources. Although nutrients, such as phosphorus fertilizers, can promote crop growth while improving soil fertility, excessive nutrient inputs can produce diffuse pollution, which may results in water quality degradation. The objective of this paper is to employ the SWAT (Soil and Water Assessment Tool) to estimate diffuse P effects on temporal and spatial distributions for a typical agricultural watershed and to identify the conjunct and independent influences of long-term land use and soil properties variation on diffuse P. With the validated model, the four-period simulation results (from 1979 to 2009) indicate that land use changes from agricultural development increased diffuse P yields. However, regarding updated soil properties, no significant differences of P yield were found between 1979 and 2009, demonstrating that impact of the cropland expansion were naturalized with soil property variations. An F-test was employed to assess the essentiality of all of the variables examined during the simulation period, and the test results indicated that diffuse P loading was more sensitive to soil properties than to land use. Before the P pollution control project about the land use optimization planning, it is more effective to distinguish the impacts of land use and soil properties
FIGURE 4 in Morphological studies and molecular data on a new marine ciliate, Apokeronopsis sinica n. sp. (Ciliophora: Urostylida), from the South China Sea
No full textFIGURE 4. Unmatched sites from SSrRNA gene sequences alignment. Numbers represent the positions of the nucleotides. Missing sites are compensated by gaps (-). Matched sites are marked with dots (.).Published as part of <i>Liu, Weiwei, Li, Jiqiu, Gao, Shan, Shao, Chen, Gong, Jun, Lin, Xiaofeng, Liu, Hongbin & Song, Weibo, 2009, Morphological studies and molecular data on a new marine ciliate, Apokeronopsis sinica n. sp. (Ciliophora: Urostylida), from the South China Sea, pp. 57-66 in Zootaxa 2005 (1)</i> on page 63, DOI: 10.11646/zootaxa.2005.1.5, <a href="http://zenodo.org/record/10093145">http://zenodo.org/record/10093145</a>
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
Seasonal variability of picoplankton in the Northern South China Sea at the SEATS station
No full textDispelling 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
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