957 resultados para Bailey, Pearl
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At first, the article has an introduction of the basic theory of magnetotelluric and the essential methods of data acquisition and preprocessing. After that, the article introduces the methods together with their predominance of computing transfering function such as the Least-square method, the Remote-Reference method and the Robust method. The article also describe the cause and influence of static shift, and has a summarize of how to correct the static shift efficiently, then emphasizes on the theories of the popular impedance tensor decomposition methods as Phase-sensitivity method, Groom and Bailey method, General tensor-analyzed method and Mohr circle-analyzed method. The kernal step of magnetotelluric data-processing is inversion, which is also an important content of the article. Firstly, the article introduces the basic theories of both the popular one-dimensional inversion methods as Automod, Occam, Rhoplus, Bostick and Ipi2win and the two-dimensional inversion methods as Occam, Rebocc, Abie and Nlcg. Then, the article is focused on parallel-analysis of the applying advantage of each inversion method with practical models, and obtains meaningful conclusion. Visual program design of magnetotelluric data-processing is another kernal part of the article. The bypast visual program design of magnetotelluric data-processing is not satisfied and systemic, for example, the data-processing method is single, the data-management is not systemic, the data format is not uniform. The article bases the visual program design of magnetotelluric data-processing upon practicability, structurality, variety and extensibility, and adopts database technology and mixed language program design method; finally, a magnetotelluric data management and processing system that integrates database saving and fetching system, data-processing system and graphical displaying system. Finally, the article comes onto the magnetotelluric application.takeing the Tulargen Cu-Ni mining area in Xingjiang as the practical example, using the data-processing methods introduced before, the article has a detailed introduction of magnetotelluric data interpretation procedure.
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河流是连接海洋和陆地生态系统的重要途径,也是全球碳循环研究的重要环节。因此,河水的水文地球化学研究是获得有关流域侵蚀、风化以及元素在大陆- 河流- 海洋系统中外生循环过程等的重要途径。由于碳酸盐岩风化作用的产物在很大程度上控制着地表水系的地球化学组成, 因此对碳酸盐岩地区河流的水文地球化学特征的研究, 对于了解碳酸盐岩地区的侵蚀、风化强度以及河流地球化学组成变化的多种控制因素有很大的意义。 单就珠江水系而言,目前该方面的研究范围较窄,主要集中于珠江流域水文气候监测、水体有机污染物的迁移转化以及珠江三角洲与河口水体的同位素示踪研究等几个方面,而对于典型气候、地质地貌区域内的各支流的系统的水文地球化学研究少之又少。事实上,对于珠江水系的干流西江而言,流域内由于喀斯特地貌广泛发育,具有极强的地理特异性,因而各支流在不同地质地貌特征、土壤、气候、植被等条件下的水文地球化学的系统研究以及同位素示踪流域侵蚀状况等方面的研究,不仅对于更好地了解中国西南地区典型喀斯特岩溶区域内土壤、岩石的化学风化、水土流失、水文地球化学特征以及环境污染等方面具有极其重要的意义,同时也对全球碳循环的系统研究有着极其重要的研究价值。 本研究在导师刘丛强研究员主持的国家重大基础规划“973”计划项目“西南喀斯特山地石漠化与适应性生态系统调控”课题的支持下开展完成,选择贵州境内珠江水系干流西江及其支流(红水河流域),以及一级支流柳江源头都柳江及其支流为研究对象,分别通过对流域内,变质碎屑岩以及海相碳酸盐岩两大岩性区域内不同植被覆盖状况下各地表水体中水文地球化学特征以及碳同位素地球化学特征分析,得出以下结论: 1、流域岩性特征是控制流域内各地表水体水文地球化学特征以及流域风化侵蚀程度的重要影响因素。与此同时,研究区内由于人为活动造成的水体污染对于地表水体离子组成特征的变化,也有一定的影响。 2、研究区珠江流域内的地表水体来源主要为大气降水和地下水。研究区内的受西南季风影响下的频繁的降雨过程,是研究区地表水体的主要补给源。研究区内大气降水大多透过表层土壤,进入深部土壤含水层后,或以地表径流的形式冲刷土壤岩石表层后汇入流域内地表河流;或参与地下水体循环,最终以地下水补给地表河流。研究区内NNE方向褶皱断裂构造极其发育,地表河网与地下河网相互连接,转换频繁。 3、研究区内地表水体的离子组成特征以及物理化学性质,主要受流域内土壤岩石化学风化过程的控制。不同岩性特征区域内,地表水体的离子组成特征以及水化学参数有着显著的差异。 4、通过对贵州境内珠江水系75个地表水体中三种不同形态碳DIC、DOC、POC及其部分稳定碳同位素的分析测试,发现研究区内地表水体中的DIC主要来源于研究区内土壤CO2对不同流域内土壤、岩石矿物的化学风化过程。一般而言,植被覆盖状况较好的区域,土壤CO2较为丰富,化学风化作用较为强烈;碳酸盐岩比硅酸盐类易于风化,并且不同岩性区域化学风化过程可以使得地表水体具有不同的离子组成特征与水化学特性。 5、研究区各流域地表水体中的有机碳主要与流域内植被状况相关。地表水体中DOC浓度在一定程度上反映了流域内的植被状况,而TSS以及POC则反映了流域内土壤有机质的情况。研究区地表水体中DOC、POC含量变化情况,是探讨喀斯特地区碳的源汇关系及循环模式的重要依据。 6、河流悬浮物中的POC主要来源于土壤有机质和陆地植物,是研究流域侵蚀问题的重要指标。研究区内变质碎屑岩以及海相碳酸盐岩区域内各地表水体均表现出δ13CPOC 与TOC/TN之间的负相关关系,且地表水体中颗粒有机物具有较低的TOC/TN,表明研究区内各地表水体中POC很可能来源于深层土壤。水动力越强,流域侵蚀越强烈,因而TSS中TOC/TN越低。
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Pint?r, B.; Thom, S. D.; Balthazor, R.; Vo, H.; Bailey, G. J., Modeling subauroral polarization streams equatorward of the plasmapause footprints, Journal of Geophysical Research, Volume 111, Issue A10, CiteID A10306 RAE2008
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Y. Zhu, S. Williams and R. Zwiggelaar, 'Computer technology in detection and staging of prostate carcinoma: a review', Medical Image Analysis 10 (2), 178-199 (2006)
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Jenkins, Tudor; Hayton, D.J.; Bailey, P.; Noakes, T.C.Q., (2002) 'Optical and ion-scattering study of SiO2 layers thermally grown on 4H-SiC', Semiconductor Science and Technology 17 pp.L29-L32 RAE2008
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No abstract is available.
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BRCA1 has been implicated in numerous DNA repair pathways that maintain genome integrity, however the function responsible for its tumor suppressor activity in breast cancer remains obscure. To identify the most highly conserved of the many BRCA1 functions, we screened the evolutionarily distant eukaryote Saccharomyces cerevisiae for mutants that suppressed the G1 checkpoint arrest and lethality induced following heterologous BRCA1 expression. A genome-wide screen in the diploid deletion collection combined with a screen of ionizing radiation sensitive gene deletions identified mutants that permit growth in the presence of BRCA1. These genes delineate a metabolic mRNA pathway that temporally links transcription elongation (SPT4, SPT5, CTK1, DEF1) to nucleopore-mediated mRNA export (ASM4, MLP1, MLP2, NUP2, NUP53, NUP120, NUP133, NUP170, NUP188, POM34) and cytoplasmic mRNA decay at P-bodies (CCR4, DHH1). Strikingly, BRCA1 interacted with the phosphorylated RNA polymerase II (RNAPII) carboxy terminal domain (P-CTD), phosphorylated in the pattern specified by the CTDK-I kinase, to induce DEF1-dependent cleavage and accumulation of a RNAPII fragment containing the P-CTD. Significantly, breast cancer associated BRCT domain defects in BRCA1 that suppressed P-CTD cleavage and lethality in yeast also suppressed the physical interaction of BRCA1 with human SPT5 in breast epithelial cells, thus confirming SPT5 as a relevant target of BRCA1 interaction. Furthermore, enhanced P-CTD cleavage was observed in both yeast and human breast cells following UV-irradiation indicating a conserved eukaryotic damage response. Moreover, P-CTD cleavage in breast epithelial cells was BRCA1-dependent since damage-induced P-CTD cleavage was only observed in the mutant BRCA1 cell line HCC1937 following ectopic expression of wild type BRCA1. Finally, BRCA1, SPT5 and hyperphosphorylated RPB1 form a complex that was rapidly degraded following MMS treatment in wild type but not BRCA1 mutant breast cells. These results extend the mechanistic links between BRCA1 and transcriptional consequences in response to DNA damage and suggest an important role for RNAPII P-CTD cleavage in BRCA1-mediated cancer suppression.
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In celebration of the 250th anniversary of the birth of Charles Carroll of Carrollton, Archaeology in Annapolis was invited to excavate the Carroll House and garden on 107 Duke of Gloucester Street in Annapolis, Maryland. The site, named the St. Mary's Site (18AP45) for the Catholic church on the property, is currently owned by the Redemptorists, a Roman Catholic congregation of priests and brothers who have occupied the site since 1852. Prior to the Redemptorists' tenure, the site was owned by the Carroll family from 1701-1852 and is perhaps best known as the home of Charles Carroll of Carrollton (1737-1832), signer of the Declaration of Independence. Excavations at the site were conducted during four consecutive summer seasons from 1987-1990. The investigation focused on three research questions. The first line of inquiry were questions surrounding the dating, architectural configuration, and artifact deposits of the "frame house," a structure adjoining the west wall of the brick Carroll House via a "passage" and later a three story addition. The frame house was partially demolished in the mid-nineteenth century but the construction was thought to pre-date the brick portion of the house. The second research question was spurred by documentary research which indicated that the property might have been the location of Proctor's Tavern, a late 17th-century tavern which served as the meeting place of the Maryland Provincial Assembly. Archaeological testing hoped to determine its location and, if found, investigate Annapolis' early Euro-American occupation. The third research question focused on the landscape of the site as it was shaped by its occupants over the past three hundred years. The research questions included investigating the stratigraphy, geometry, and architectural and planting features of Charles Carroll of Carrollton's terraced garden built during the 1770s, and investigating the changes to the landscape made by the Redemptorists in the nineteenth and twentieth centuries. While no structural evidence associated with Proctor’s Tavern was uncovered during limited excavations along Spa Creek, the historic shore of Spa Creek was identified, buried beneath deep fill deposits laid down during construction of the Carroll Garden. Features and deposits associated with this period likely remain intact in a waterlogged environment along the southeastern sea wall at the St. Mary’s Site. Evidence of extensive earth moving by Carroll is present in the garden and was identified during excavation and coring. This strongly suggests that the garden landscape visible at the St. Mary’s Site is the intact Carroll Garden, which survives beneath contemporary and late nineteenth century strata. The extant surviving garden should be considered highly sensitive to ground-disturbing activities, and is also highly significant considering demonstrable associations with the Carroll family. Other garden-related features were also discovered, including planting holes, and a brick pavilion or parapet located along Spa Creek to the south of the site. The Duke of Gloucester Street wall was shown to be associated with the Carroll occupation of the site. Finally, intensive archaeological research was directed at the vicinity of a frame house constructed and occupied by the Carrolls to the east of the existing brick house, which was replaced by the Redemptorists in the nineteenth century with a greenhouse. These superimposed buildings were documented in detail and remain highly significant features at the St. Mary’s Site.
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From tendencies to reduce the Underground Railroad to the imperative "follow the north star" to the iconic images of Ruby Bridges' 1960 "step forward" on the stairs of William Frantz Elementary School, America prefers to picture freedom as an upwardly mobile development. This preoccupation with the subtractive and linear force of development makes it hard to hear the palpable steps of so many truant children marching in the Movement and renders illegible the nonlinear movements of minors in the Underground. Yet a black fugitive hugging a tree, a white boy walking alone in a field, or even pieces of a discarded raft floating downstream like remnants of child's play are constitutive gestures of the Underground's networks of care and escape. Responding to 19th-century Americanists and cultural studies scholars' important illumination of the child as central to national narratives of development and freedom, "Minor Moves" reads major literary narratives not for the child and development but for the fugitive trace of minor and growth.
In four chapters, I trace the physical gestures of Nathaniel Hawthorne's Pearl, Harriet Beecher Stowe's Topsy, Harriet Wilson's Frado, and Mark Twain's Huck against the historical backdrop of the Fugitive Slave Act and the passing of the first compulsory education bills that made truancy illegal. I ask how, within a discourse of independence that fails to imagine any serious movements in the minor, we might understand the depictions of moving children as interrupting a U.S. preoccupation with normative development and recognize in them the emergence of an alternative imaginary. To attend to the movement of the minor is to attend to what the discursive order of a development-centered imaginary deems inconsequential and what its grammar can render only as mistakes. Engaging the insights of performance studies, I regard what these narratives depict as childish missteps (Topsy's spins, Frado's climbing the roof) as dances that trouble the narrative's discursive order. At the same time, drawing upon the observations of black studies and literary theory, I take note of the pressure these "minor moves" put on the literal grammar of the text (Stowe's run-on sentences and Hawthorne's shaky subject-verb agreements). I regard these ungrammatical moves as poetic ruptures from which emerges an alternative and prior force of the imaginary at work in these narratives--a force I call "growth."
Reading these "minor moves" holds open the possibility of thinking about a generative association between blackness and childishness, one that neither supports racist ideas of biological inferiority nor mandates in the name of political uplift the subsequent repudiation of childishness. I argue that recognizing the fugitive force of growth indicated in the interplay between the conceptual and grammatical disjunctures of these minor moves opens a deeper understanding of agency and dependency that exceeds notions of arrested development and social death. For once we interrupt the desire to picture development (which is to say the desire to picture), dependency is no longer a state (of social death or arrested development) of what does not belong, but rather it is what Édouard Glissant might have called a "departure" (from "be[ing] a single being"). Topsy's hard-to-see pick-pocketing and Pearl's running amok with brown men in the market are not moves out of dependency but indeed social turns (a dance) by way of dependency. Dependent, moving and ungrammatical, the growth evidenced in these childish ruptures enables different stories about slavery, freedom, and childishness--ones that do not necessitate a repudiation of childishness in the name of freedom, but recognize in such minor moves a fugitive way out.
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Solder materials are used to provide a connection between electronic components and printed circuit boards (PCBs) using either the reflow or wave soldering process. As a board assembly passes through a reflow furnace the solder (initially in the form of solder paste) melts, reflows, then solidifies, and finally deforms between the chip and board. A number of defects may occur during this process such as flux entrapment, void formation, and cracking of the joint, chip or board. These defects are a serious concern to industry, especially with trends towards increasing component miniaturisation and smaller pitch sizes. This paper presents a modelling methodology for predicting solder joint shape, solidification, and deformation (stress) during the assembly process.
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A computational model of solder joint formation and the subsequent cooling behaviour is described. Given the rapid changes in the technology of printed circuit boards, there is a requirement for comprehensive models of solder joint formation which permit detailed analysis of design and optimization options. Solder joint formation is complex, involving a range of interacting phenomena. This paper describes a model implementation (as part of a more comprehensive framework) to describe the shape formation (conditioned by surface tension), heat transfer, phase change and the development of elastoviscoplastic stress. The computational modelling framework is based upon mixed finite element and finite volume procedures, and has unstructured meshes enabling arbitrarily complex geometries to be analysed. Initial results for both through-hole and surface-mount geometries are presented.
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In this paper a computer simulation tool capable of modelling multi-physics processes in complex geometry has been developed and applied to the casting process. The quest for high-quality complex casting components demanded by the aerospace and automobile industries, requires more precise numerical modelling techniques and one that need to be generic and modular in its approach to modelling multi-processes problems. For such a computer model to be successful in shape casting, the complete casting process needs to be addressed, the major events being:-• Filling of hot liquid metal into a cavity mould • Solidification and latent heat evolution of liquid metal • Convection currents generated in liquid metal by thermal gradients • Deformation of cast and stress development in solidified metal • Macroscopic porosity formation The above phenomena combines the analysis of fluid flow, heat transfer, change of phase and thermal stress development. None of these events can be treated in isolation as they inexorably interact with each other in a complex way. Also conditions such as design of running system, location of feeders and chills, moulding materials and types of boundary conditions can all affect on the final cast quality and must be appropriately represented in the model.
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A brief description of a software environment in FORTRAN77 for the modelling of multi-physics phenomena is given. The numerical approach is based on finite volume methods but extended to unstructured meshes (ie. FV-UM). A range of interacting solution procedures for turbulent fluid flow, heat transfer with solidification/melting and elasto-visco-plastic solid mechanics are implemented in the first version of PHYSICA, which will be released in source code form to the academic community in late 1995.