4,500,582 research outputs found
Atlas of global sea level pressure (1871AD~1980AD)
No full textThis is an atlas of global gridded SLP (10deg x 10deg) for Jan/Apr/Jul/Oct in 1871-1980, which was collected and hand-draw by Prof. Shaowu Wang (1932-2015). Dr. Xinyu Wen made the photocopies of all the raw plots and we would like to share these plots with the international climate community
StackOverflow Q&A Dataset
No full textThis dataset is used for the paper named "Unveiling the Effects of Large Language Models: Evidence from an UGC Platform" by Xinyu Li and Keongtae Kim
Exploring Potential Benefits of Visualizing Canopy Cover Change in 3D Gaming Engine Environment
No full textThis research explores the innovative use of a 3D gaming engine, Minetest, for visualizing changes in canopy cover change at the University of British Columbia (UBC) campus, addressing the pressing challenge of urban expansion on green spaces. We compared and visualized canopy height change for UBC campus in both 2D traditional environment and 3D gaming engine environment and we revealed a consistency between the spatial patterns of canopy cover change observed in both environments. Our findings indicate 3D environment provided multi-dimensional insights into canopy cover changes, offering decision-makers more straightforward and transparent insight than traditional maps can achieve in an immersive and interactive environment. We observed there is a significant change in canopy cover with 25 percent loss in total where Wesbrook community area experienced the most significant canopy cover loss in past 5 years due to rapid urban development. Our findings goes beyond merely presenting geographic maps and attributes from a 3D voxel game perspective. Instead, it will serve as a useful tool and references for UBC decision makers and planners to inform management plan on the pathway of building a green, well-planned community
Adaptively combined forecasting for discrete response time series
No full textXinyu Zhang, Zudi Lu, Guohua Zo
2019-02-26 Xinyu Yang, DMA Lecture Recital
No full textThis recital is given in partial fulfillment of the requirements of the Doctor of Musical Arts degree. Xinyu is from the Studio of Professor Lin He
Polypropylene-based nanodielectrics for HVDC cables
No full textDue to the limited recyclability and operating temperature of the cross-linked polyethylene (XLPE) insulation for high voltage direct current (HVDC) cables, renewable next-generation insulation materials have drawn great attention during recent years, especially polypropylene-based nanodielectrics. The filler-matrix interphase within nanodielectrics is believed to be the determining factor in bringing unique features, which show great potential in tailoring the dielectric and thermal properties of the insulations. However, it is still unsatisfactory in understanding how interphase works. In this study, polypropylene (PP) and aluminium nitride (AlN) nanocomposites have been investigated regarding their potential application for HVDC cable insulation. A conceptional model (two-side model) is proposed to explain the behaviours of PP nanocomposites contains the silane coupling agents (SCA) treated fillers. The novelty of this model is to divide the surface chemistry of fillers into two sides (the near- and far-particles sides) at the molecular level, which differs from the conventional theory that the interphase properties are dominated by the interaction between the organofunctional tails (far-particle side) of SCA and polymer matrix. The bonding structure between SCA and particle surface (near-particle side) also executes a strong influence on the filer-matrix interaction by modifying the polarity of the particle surface, e.g., the monolayer of SCA on nanoparticles surface can maintain the polarity of the AlN then provide an inter spherulitesboundary-free structure, thus giving a higher dielectric break down strength compared to systems contains AlN with a multilayer of SCA. Four SCA were used to analyse the effect of the AlN surface chemistry that differ in the near- and far-particle structures on the morphology, thermal, and dielectric properties of nanocomposites. The introduction of AlN shows a nucleating and hindrance effect, increasing the nuclei density but maintaining the crystallinity of the nanocomposites. AlN with higher surface polarity presents a higher nucleating effect and can induce an inter-spheruliteboundary-free structure where the AC breakdown strength is improved. Such so called surface polarity is positively related to both the near- and far-particles sides. A water absorption analysis was used to investigate the interphase properties of the nanocomposites, as the absorbed water molecules will mainly be located at the interfacial region. The AlN filled PP was found to reduce the hydrophobicity of PP, result in an increased permittivity and dielectric loss. This issue can be mitigated by using tri-alkoxy silanes to form a silane network that repels water molecules; meanwhile, the mono-alkoxy silane cannot increase the hydrophobicity of the nanocomposites. Despite the AlN dispersion can be improved by SCA treatment, large agglomerations (> 20 µm) can still be observed in silane treated samples caused by the hydrolysis of AlN. The removal rather than dispersing of those large agglomerations by a centrifugal separation method gives us an excellent opportunity to investigate the relationship between bulk properties and the degree of AlN agglomeration. It is found that the AC breakdown strength is significantly improved after the separation process compared to the PP with non-separated AlN. The improved nanoparticle dispersion reduced the defects and cavities within nanocomposites; benefit from that, the samples still exhibit an excellent hydrophobicity even the interfacial area is increased. The addition of SCA increases the thermal conductivity of the PP/AlN nanocomposites, where 10 % of the increase can be achieved. Although the total interfacial thermal resistance increases with the increased AlN dispersion after the centrifugal separation processes, there is a higher chance for the fillers to percolate, thus showing a comparable bulk conductivity. Overall, this study investigated the influence of the material interphase on the morphology, thermal, and electrical properties of nanocomposites using a proposed two-side model (near- and farparticle side), which is expected to serve as a valuable tool in the future design and application of nanodielectrics
The effect of water on the dielectric properties of polypropylene/aluminium nitride nanocomposites
No full textA series of aluminium nitride/polypropylene nanocomposites were prepared. Nano aluminium nitride was surface functionalised by silane coupling agents with different hydrolysable groups and the effect of the surface chemistry and preconditioning (i.e., under different relative humidity) on their AC breakdown strength and the DC conductivity was investigated. The effect of water on the nanosilica-based nanocomposites have been studied by many researchers and the dramatically decreased AC breakdown strength and DC resistivity for wet samples were reported[1, 2]. By contrast, aluminium nitride filler with less hydrophilic sites, hydroxyl groups, was applied in this study. Furthermore, octyl silanes were adopted and the displacement of hydroxyl groups to short carbon chain on the particle surface is expected.The preconditioning results show that the silane functionalisation can effectively reduce the amount of water absorbed during 15 days of immersion in deionized water. The dielectric properties show a high dependency on the sample preconditioning and water content. The DC conductivity of the non-treated aluminium nitride/polypropylene nanocomposites is 2 orders of magnitude higher than the octyl functionalised silane. Similar behaviour was observed on the AC breakdown data. However, the difference between systems treated with silane coupling agent with different hydrolysable groups cannot be seen from the weight monitoring and dielectric properties mentioned above. Although the dielectric results in [3] show the different hydrolysable groups might bring different bonding structure between nanoparticle and silane coupling agents, the interaction with water seems to have less dependency on it.In this study, It can be concluded that the nanoparticle surface chemistry is very important in determining the macroscopic properties, especially in a humid environment. The surface functionalisation by silane coupling agent can effectively minimise the hydrophobicity of nanocomposites.[1] D Qiang, Y Wang, G Chen, and T. Andritsch, "Influence of Water Absorption on Space Charge Behavior of Epoxy Nanocomposites," 2016.[2] I. Hosier, M. Praeger, A. Holt, A. Vaughan, and S. Swingler, "On the effect of functionalizer chain length and water content in polyethylene/silica nanocomposites: Part I—Dielectric properties and breakdown strength," IEEE Transactions on Dielectrics and Electrical Insulation, vol. 24, no. 3, pp. 1698-1707, 2017.[3] X. Wang, T. Andritsch, and G. Chen, "Effect of Surface Functionalization on the Dielectric Properties of Polypropylene Aluminium Nitride Nanocomposites," in 2018 IEEE 2nd International Conference on Dielectrics (ICD), 2018, pp. 1-4: IEEE
Wang Shuo and the commercialisation of contemporary Chinese culture
No full textThis thesis examines the commercialisation of Chinese culture that has taken place over the past twenty years in mainland China. It explores the contribution of Wang Shuo, a cultural figure who straddles different fields of culture, moving from literature to the ultimate mass culture medium of television, this study plots Wang Shuo' s development from educational failure, to business failure, to fiction writer, film & TV editor, film director and cultural critic and analyst. His stories, films, TV series and articles have caused shock-waves throughout national cultural circles as he has transformed the terms of the debate from academic discourse to a validation of the role of the market in the culture field. Although Wang Shuo has not been labelled as a dissident, his approach to the culture market has had a more subversive effect on official ideology that those overt dissidents who have had to live in exile or have been imprisoned. He has utilised the language of official ideology to satirise the authorities, turning the ideology and its supporters into figures of fun. Yet his own goals have been strictly personal and economic ones. The authorities recognize the value of Wang Shuo's work in the cultural market but at the same time distrust his works and place him under strict censorship. Examining the way Wang Shuo and people surround him have succeeded in different fields of cultural achievement is a mirror to understanding the process of the transformation of contemporary Chinese culture from a socialist state-controlled culture to a market-oriented mass culture industry
Wang Li (1900-1986)
No full textWang Li (Wang Liaoyi) was one of the three most prominent linguists in China in the 20th century. He was born August 10, 1900, in what is now Bobai County of the Guangxi Zhuang Autonomous Area
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