1,725,351 research outputs found
Taxonomy and nomenclature of Salix baileyi, S. rehderiana, and S. disperma
No full textResearchers have frequently misapplied the name Salix leveilleana C.K. Schneider to S. baileyi C.K. Schneider. After detailed study of the types, relevant specimens and literature, S. leveilleana is synonymized with S. disperma Roxb. ex D. Don. Salix dolia C.K. Schneider and S. rehderiana C.K. Schneider represent the same taxon; in this study, the later one is chosen. Furthermore, the author perfected the descriptions of S. baileyi, and amend its distribution area to include Hunan and Zhejiang, China
Taxonomy and nomenclature of Salix baileyi, S. rehderiana, and S. disperma
No full textResearchers have frequently misapplied the name Salix leveilleana C.K. Schneider to S. baileyi C.K. Schneider. After detailed study of the types, relevant specimens and literature, S. leveilleana is synonymized with S. disperma Roxb. ex D. Don. Salix dolia C.K. Schneider and S. rehderiana C.K. Schneider represent the same taxon; in this study, the later one is chosen. Furthermore, the author perfected the descriptions of S. baileyi, and amend its distribution area to include Hunan and Zhejiang, China.</jats:p
Qiongphasma Chen, He & Li 2002
No full textGenus Qiongphasma Chen, He & Li, 2002 E Qiongphasma Chen, He & Li, 2002: 106. Type-species. Qiongphasma jianfengense Chen & He, 2002: 106 (in Chen et al., 2002), by original designation. Notes. Four species and four subspecies are recognised from this Hainan endemic genus. Ho (2013d) provided redescription and key for the genus.Published as part of Ho, George Wai-Chun, 2016, Contribution to the knowledge of Chinese Phasmatodea III: Catalogue of the phasmids of Hainan Island, China, with descriptions of one new genus, one new species and two new subspecies and proposals of three new combinations, pp. 314-340 in Zootaxa 4150 (3) on page 324, DOI: 10.11646/zootaxa.4150.3.4, http://zenodo.org/record/25841
(2602) Proposal to conserve the name <i>Salix wallichiana</i> against <i>S. disperma (Salicaceae)</i>
No full textEffect of non-uniform turbulence distributions on high pressure turbine heat transfer
Full text linkThe taxonomy of flow phenomena affecting turbine blade heat transfer has been widely researched and their specific effects established. However, the literature contains minimal consideration of circumferential length scales in the freestream turbulence intensity exiting the combustor despite experimental evidence for their existence in certain combustor geometries. The amplitude in these circumferential variations is demonstrated to vary up to 60% about the circumferential average. The distribution of the heat transfer coefficient on the surface of a turbine blade responds to variation in freestream turbulence intensity. Therefore it is necessary to study the effect of this circumferential variation in turbulence on turbine blade heat transfer.This study utilized numerical methods to provide predictions of aerothermal conditions for eight high pressure turbine geometries and a NACA airfoil operating in transonic flow regimes. Included in the validation of the numerical solver were sen- sitivity studies of solver formulation and turbulence model selection. Comparative analysis using a NACA airfoil and high pressure turbine rotor blade for three solver formulations (density-based, pressure-based coupled, and pressure-based segregated) revealed that the pressure-based solvers retained improved computational efficiency and comparable aerothermal predictive performance relative to the density-based solver. However, the pressure-based solver required extensive native control at the start of the unsteady flow solutions in order to reach convergence, therefore rendering the density-based solver as the solver formulation of choice. In the parametric study of turbulence model sensitivity, the k − ω SST and Spalart-Allmaras models out-performed the others in predicting both surface pressure and heat transfer on two rotor blade profiles. In particular the k − ω SST model performed the best, predicting absolute levels of heat transfer to within 20% when the boundary-layer was fully turbulent. The two models also successfully captured the response of rotor heat transfer to variation in freestream turbulence intensity in steady flow. These turbulence models were then studied in simulations of two rotor profiles subjected to a passing upstream cylinder representing an upstream nozzle guide vane trailing edge. The two models were capable of resolving all of the unsteady flowfield features identified in previous experiments, as well as accurately predicting the time-averaged and unsteady rotor surface pressure conditions. The k − ω SST model outperformed the Spalart-Allmaras model in predicting both the time-averaged and unsteady heat transfer for the rotor subjected to a passing upstream bar. The accuracy of the k − ω SST model prediction of time-averaged rotor heat transfer was within 20% in fully turbulent regions of the rotor boundary-layer. Following final tuning, this high-performing turbulence model was used solely in the study of non-uniform inlet turbulence conditions.The effectiveness of the code in predicting the aerodynamics and heat transfer in a range of validation studies provided justification for a numerical analysis of engine-representative turbulence intensity variation. This thesis employs circumferential freestream turbulence intensity variation in amplitudes ranging from 30% to 60%. Hot streaks were simulated at two ratios of maximum to minimum total temperature in the circumferential direction with values of 1.1 and 1.4. Combining the two distortions in phase allowed for the assessment of clocking on vane heat transfer. Combustor burner to vane count was simulated at 1:1 and 2:1. The predictions consistently showed the dependence of vane heat transfer coefficient distributions on turbulence distortion clocking to be on the order of 20%. This effect scaled on the amplitude of the circumferential turbulence variation. Simulations on a three-dimensional vane concurred with the two-dimensional results. These turbulence distortions propagated to the downstream rotor blade row, and altered rotor heat transfer unsteadiness. Overall, the engine-representative “turbulence streak” presents a new source of heat transfer that requires further experimental confirmation, creating another design variable to consider for turbine heat transfer engineers
Lun dian ying de bian ju dao yan he yan yuan.
No full text普多夫金[普陀符金]著 ; 孟太格(I. Montagu)英译 ; 何力汉译.Puduofujin [Putuofujin] zhu ; Mengtaige (I. Montagu) Ying yi ; He Li Han yi
Nanhuaphasma Chen, He & Li 2002
No full textGenus Nanhuaphasma Chen, He & Li, 2002 Nanhuaphasma Chen et al., 2002: 100, figs. 1a–b. Type-species. Nanhuaphasma hamicercum Chen & He, 2002 (in Chen et al., 2002), by original designation.Published as part of Ho, George Wai-Chun, 2016, Contribution to the knowledge of Chinese Phasmatodea III: Catalogue of the phasmids of Hainan Island, China, with descriptions of one new genus, one new species and two new subspecies and proposals of three new combinations, pp. 314-340 in Zootaxa 4150 (3) on page 332, DOI: 10.11646/zootaxa.4150.3.4, http://zenodo.org/record/25841
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
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