6,837 research outputs found
Using performance assessment in secondary school mathematics: an empirical study in a Singapore classroom
No full textThis article reports an exploratory study on using performance assessment in mathematics instruction in a high-performing secondary school in Singapore. An intact mathematics class participated in the study, and received chapter-based performance tasks as intervention during regular mathematics lessons for about one and a half school years. The performance tasks used included authentic and/or open-ended tasks. The students’ academic achievements and attitudes in mathematics were compared with a comparison class that did not receive the intervention. Both quantitative and qualitative data were collected, mainly through questionnaire surveys, performance task tests, conventional school exams, and interviews with students and teachers. The results suggest that the students receiving the intervention performed significantly better than their counterparts in solving conventional exam problems, and in general they also showed more positive changes in attitudes towards mathematics and mathematics learning. The students from the experimental class also expressed positive views about the benefits of using performance tasks in promoting their ability in higher order thinking, though no statistically significant difference was detected between the two classes of students in solving unconventional tasks before and after intervention. Overall, the results appear to support teachers’ using contextualised problems in real life situations and open-ended investigations in students’ learning of mathematic
Richardson, Barbauld, and the construction of an early modern fan club
No full textMPhilMuch has been written about the life and long works of the eighteenth century epistolary novelist, Samuel Richardson, but the prospect of his position as the first celebrity novelist – responsible for courting his own fame as well as initiating his own fan club – has largely been ignored. The body of manuscripts housed at the National Art Library in the Victoria and Albert Museum in London provides the modern scholar with evidence of the skeletal beginnings of an early fan club. This thesis aims to show how these manuscripts were turned into a saleable commodity by the publisher and entrepreneur Richard Phillips, while under the guiding hand of another, slightly later, literary celebrity, Anna Laetitia Barbauld. In order to restore Richardson’s reputation amongst a new nineteenth century audience, Barbauld was required to construct her own idea of him as an eighteenth century celebrity author, and in doing so the insecurities of a self-professed, apparently diffident man, are revealed. Barbauld’s capacious, but heavily edited selection of letters is analyzed in this thesis, providing ample evidence that Richardson’s correspondents were more than just eager letter writers. By using Barbauld’s biography of Richardson this thesis aims to show how she manipulates the genre of life writing in her construction of him.
This thesis offers an alternative reading of how the Richardson manuscripts are viewed, redefining them as not simply a collection of letters, but as a collective entity, deliberately selected and archived as evidence of an early modern fan club, and its celebrity managing director
The spore-pollen assemblages of the Miocene Baode Formation from Borehole ZK301 in the Yuncheng Basin and its geological significance
No full textThe deposition period of the Baode Formation in the Miocene was crucial when the uplift and expansion of the Tibetan Plateau in the NE direction affected the Cenozoic basins around the Ordos Plateau. Previous research has mainly focused on tectonic and sedimentary aspects, with relatively few results on climate and environmental responses. We conducted a systematic sporopollen study on the Borehole ZK301 from the late Miocene Baode Formation in the E’mei tableland, Yuncheng Basin, characterized the deposited and redeposited spore-pollen and discussed the paleoclimate and paleotectonic background of the Baode Formation during its deposition. From bottom to top, the Miocene Baode Formation in the Yuncheng Basin can be divided into two spore-pollen assemblages, which are Ephedraceae–Chenopodiaceae–Gramineae zone and Artemisia–Chenopodiaceae–Humulus zone, indicating that the desert steppe dominated by Chenopodiaceae, Gramineae, and Ephedraceae developed into the desert steppe dominated by Artemisia and Chenopodiaceae in the late Miocene. Accordingly, the climate transitioned from relatively cold and dry to cold and dry, which was related to the influence of the remote effect of the uplift and expansion of the Tibetan Plateau on the climate in the late Miocene. The redeposited spore-pollen assemblages are mainly concentrated in the lower part of the Baode Formation, with the highest content of Ephedraceae, followed by Pinus, Picea, Cupressaceae, Chenopodiaceae, Juglandaceae and Pteridophyte, and a small amount of Classopollis and Elaeagnaceae, reflecting a warm and humid climate. The redeposited spore-pollens were mainly from the Paleogene strata on the northern margin of the Zhongtiaoshan Mountains, which indicates that there was a rapid uplift and denudation of the Zhongtiaoshan Mountains in the early stage of the Baode Formation deposition. The Baode Formation underwent the Paleogene strata’s denudation, transportation, and redeposited process. The research results can provide evidence for the late Miocene paleoclimate in the Yuncheng Basin and new evidence for the uplift of the Zhongtiaoshan Mountains in this period
Development of a rotor model for the numerical simulation of helicopter exterior flow-fields
No full textIncludes bibliographical references (leaves 84-85).A numerical methodology is developed to model the effect of a rotor on the surrounding flow-field. The model calculates the time-averaged aerodynamic forces exerted on the air by the fan blades within the blade-swept region, and permits the user to specify blade properties such as cross-sectional profile and orientation at a particular radial and azimuthal location. The calculated forces are included as source terms within the Reynolds-averaged Navier-Stokes equations for an incompressible fluid, which are solved by the commercial CFD solver, FLUENT. The effects of turbulence are incorporated through the use of Launder and Spalding's k-g turbulence model. This method is selected as being the most efficient use of the resources available, giving the economic advantages of a steady simulation, while allowing radial and azimuthal variations of rotor characteristics. In order to validate the accuracy of the numerical model for both aligned and non-aligned inflow conditions, results are compared with experimental data reported for an axial flow fan. Agreement between experimental and numerical results is excellent to good. Fan static pressure rise is closely predicted by the numerical solution, while fan power consumption and fan static efficiency are under and over-predicted respectively. This error may be attributed to frictional losses not accounted for in the numerical model. These include physical rotational instabilities, leading to increased mechanical losses, and tip effects due to the clearance between the fan blade tips and the fan casing. Trends are nevertheless consistently predicted by the numerical model for inflow angles up to 45°, and for the range of blade pitch settings used. The adverse effect of off-axis inflow on the fan static pressure rise is numerically predicted, while fan power consumption is found to remain independent of inflow angle, as had been experimentally observed. The rotor model is finally integrated with the fuselage of the CIRSTEL (Combined Infra-Red Suppression and Tail rotor Elimination) prototype in an analysis of the helicopter exterior flow-field. No experimental data for this configuration was available for validation purposes. However, the model is used in the simulation of several common helicopter flight conditions. Results are presented graphically, and generally indicate good agreement with physically observed phenomena
Hydrophoria pronata Fan & Qian 1984
No full textpronata Fan & Qian in Fan et al., 1984a: 245 (Hydrophoria). Holotype male with labels: (1) printed with handwritten inscriptions on white label: “ Qinghai Nuomuhong / 75.7.16 / collector Ya Wu ”; (2) handwritten on white label: “pea fields”; (3) handwritten on yellow label: “ Qinghai Institute of Biology, Ya Wu took it back in 1975”; (4) printed with handwritten inscriptions on pink label: “ TYPE / Hydrophoria / pronata / Fan et Qian / 1980 ”; (5) printed with handwritten inscriptions on red label: “ TYPE / Hydrophoria / pronata / Fan et Qian ”. Preservation: pinned. Missing parts: tibia and tarsus of left mid leg, right fore leg. Paratype male with labels: (1) handwritten on white label: “Baode bankes of Yellow River / 78. VII.12”; (2) handwritten on white label: “ Pegoplata sp. ♂ ”; (3) handwritten on white label: “19”; (4) printed with handwritten inscriptions on pink label: “ PARATYPE / Hydrophoria / pronata Fan / et Qian / 1980 ”; (5) handwritten on yellow label: “bring in 79/III / Shanxi Medical College ”; (6) handwritten on white label: “ Hydrophoria albiceps ”. Preservation: pinned; specimen intact. Additional notes: Paratype collected at Baode banks of Yellow River, Shanxi Province; labels of holotype and paratype pinned by Zide Fan, but the date of collection on the label (75.7.16/78. VII.12) do not match with the date in the original publication (1975.VII.6). Current name: Hydrophoria pronata Fan & Qian, 1984.Published as part of ZHANG, XUFENG & ZHU, WEIBING, 2014, The types of Anthomyiidae (Diptera) in the Shanghai Entomological Museum, Chinese Academy of Science, China, pp. 1-67 in Zootaxa 3756 (1) on page 44, DOI: 10.11646/zootaxa.3756.1.1, http://zenodo.org/record/503313
Study on the Effect of Salinity and Water Content on CBM Adsorption/Desorption Characteristics of Coal Reservoir in Baode Block
No full textThe adsorption/desorption characteristics of a coal reservoir play an important role in coalbed methane (CBM) development. The proximate analysis, maceral analysis and methane isothermal adsorption/desorption experiment are carried out based on coal samples from no. 4+5 coal seam in Baode block. Combing with coal experimental data and the CBM well-produced water salinity data in the Baode block, the effect of salinity and water content on CBM adsorption/desorption characteristics of the coal reservoir and its influencing mechanism is discussed. The results show that the CBM adsorption and desorption capacity decreases with the increase of water salinity and the decrease value shows a decreasing trend. The increase of water salinity reduces the solubility of methane in coal seam water and then reduces the adsorption capacity of methane. With the increase of water content, the adsorption and desorption capacities of CBM decrease gradually. The CBM adsorption and desorption capacities decrease with the increase of water content in coal samples. The adsorption/desorption capacities of coal samples change rapidly in the low-water content stage and slowly in the high-water content stage. The competitive adsorption effect and water blocking effect between water and methane molecules are the main influencing mechanisms of water content on CBM adsorption/desorption. It can be seen that the salinity and water content will have a certain adverse impact on the adsorption and desorption capacity of CBM in the Baode block. The influence of the difference in water content and salinity in the coal seam cannot be ignored in reserve evaluation and productivity prediction of CBM. The continuous, stable, and effective drainage is one of the key factors to ensure the efficient development of CBM wells in the Baode block
Fan Fiction and Copyright: Outsider Works and Intellectual Property Protection
No full textAs long as there have been fans, there has been fan fiction. There seems to be a fundamental human need to tell additional stories about the characters after the book, series, play or movie is over. But developments in information technology and copyright law have put these fan stories at risk of collision with the content owners’ intellectual property rights. Fan fiction has long been a nearly invisible form of outsider art, but over the past decade it has grown exponentially in volume and in legal importance. Because of its nature, authorship, and underground status, fan fiction stands at an intersection of key issues regarding property, sexuality, and gender. In Fan Fiction and Copyright, author Aaron Schwabach examines various types of fan-created content and asks whether and to what extent they are protected from liability for copyright infringement. Professor Schwabach discusses examples of original and fan works from a wide range of media, genres, and cultures. From Sherlock Holmes to Harry Potter, fictional characters, their authors, and their fans are sympathetically yet realistically assessed. Fan Fiction and Copyright looks closely at examples of three categories of disputes between authors and their fans: Disputes over the fans’ use of copyrighted characters, disputes over online publication of fiction resembling copyright work, and in the case of J.K. Rowling and a fansite webmaster, a dispute over the compiling of a reference work detailing an author's fictional universe. Offering more thorough coverage of many such controversies than has ever been available elsewhere, and discussing fan works from the United States, Brazil, China, India, Russia, and elsewhere, Fan Fiction and Copyright advances the understanding of fan fiction as transformative use and points the way toward a safe harbor\u9d for fan fiction
Learning of algorithms: a theoretical model with focus on cognitive development
No full textTaking a broad perspective on algorithm in mathematics, the author presents a theoretical model about the learning and teaching of algorithm with focus on students’ cognitive development. The model consists of three cognitive levels: 1. Knowledge and Skills, 2. Understanding and Comprehension, and 3. Evaluation and Construction. The model suggests that teaching and learning of algorithm does not simply mean routine learning, memorization, or lead to a low level of cognition. The paper also discusses different teaching strategies and activities that can be used to support students’ cognitive development at different cognitive levels
The author in the postinternet age: Fan works, authorial function, and the archive
No full textFifty years since Roland Barthes proclaimed the death of the author, there still exists difficulty in framing the nature of interaction between commercial (professional) creators and fan (transformative) authors. In the postinternet age, the visibility of unsanctioned (or tacitly sanctioned) derivative fictional works has only increased, as have the number of commercial creators with experience in creating derivative works for a fan audience. It has therefore become necessary to interrogate whether the author has truly died in the Barthian sense, and if not, what role the construct of the author plays in today's popular mediascape. In an analysis of the Foucauldian author function (that is, the role discursively constructed authors play relative to their work) assessing both Euro-American and Japanese histories of fan practice, a move to a more open-source style of fan practice is evident. The author in an open-source fandom functions as a heuristic device through which fans may access and search the database, as well as a means of decentralizing commercial authority over media content
Computational aerodynamic study of automotive cooling fan in blocked conditions
No full textIn this paper, a CFD study of two types of axial-flow automotive cooling fans was conducted to investigate the effects of upstream and downstream blockage on aerodynamic performance of each fan. The realizable k-ε turbulence model was applied and simulations were performed to represent an automotive engine bay and quantify performance changes as a function of blockage distance. Modeling was performed for two fan designs: one optimized for a low flow rate, high-pressure operation; and a second optimized for high flow rate, low-pressure operation. The results show that the pressure loss caused by engine blockage increases at higher vehicle speed, and decreasing blockage distance. A new relation between blockage to fan proximity and fan performance was established. It is determined that the pressure change follows a quadratic type dependence, but the coefficients may vary, depending on fan type. The fan efficiency can be improved by taking advantage of larger blockage distances at higher speeds of the vehicle. The blockage condition causes an increase in the reverse flow near the fan interface, and a dramatic increase in radial flow
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