976 resultados para Rossetti, Gabriele, 1783-1854.
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The scholars in the world have been trying to find an effective analytic algorithm of multiple hole problems usually meet in engineering designs. Though some studies on circular or elliptic holes had been achieved under specific conditions, no efforts were made to any multiple hole problems that is most significant for engineering designs. The author has made further studies on any multiple hole problems, using complex variable function method and Schwarz alternating method. After solving a series of technological difficulties, the author obtains an effective analytic algorithm, and acquires stress field and displacement field with high accuracy, which can be conducted for arbitrary many iterations according to practical accuracy requirements. In addition, th solution of stress and displacement fields, even for multiple holes of complex shapes and smaller distances. Further, the author made preliminary studies on viscoelastic displacement solution for any double holes. In terms of the obtained displacement solution of any multiple holes, this paper studies displacement back-analysis for the excavations of two tunnels, and find that the back-analysis method is accurate. Additionally, the author presents the mathematical prove of inversion uniqueness for ground stresses, elastic modulus and Poisson ratio. The author believes that the accurate analytic algorithm provided in this paper will presents an effective way to stress and displacement analysis for any multiple hole problems, optimal arrangement of multiple holes, hole shape optimization of multiple holes, etc..
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采用多接收电感耦合等离子体质谱仪(MC-ICP-Ms)对喀斯特高原湖泊红枫湖、阿哈湖水体及其主要支流水体悬浮物和一些生物样品中的锌同位素进行了测定,测试精度小于0.11%。(2SD)。结果显示,红枫湖水体与其主要支流水体悬浮物中的δ^66Zn变化范围分别为-0.29‰~0.26‰和-0.04‰~0.48‰,阿哈湖水体与其主要支流水体悬浮物中的δ^66Zn变化范围分别为-0.18‰~0.27‰和-0.17‰~0.46‰,均表现出支流中的锌同位素组成较重的特点。两湖生物样品中的δ^66Zn变化范围较大,为-0.35‰~0.57‰,说明湖泊生态系统中各端员的锌同位素组成存在一定差异。根据同位素组成分析,湖泊主要入湖河流及所携带的陆源物质是阿哈湖?白水体中锌的主要来源,锌同位素是一种较好的物源示踪工具。红枫湖夏季δ^66Zn与Chla(叶绿素)呈显著的正相关(R=0. 97),主要是藻类对锌的有机吸附和吸收过程导致锌同位素组成发生变化。此外,湖泊水体悬浮物中的锌同位素组成均在夏季较轻,表明大气的干湿沉降可能是一个较负的锌同位素源。水体悬浮物中的δ^66Zn变化范围小于生物样品中的δ^66Zn变化范围,说明由于生物作用过程导致的锌同位素分馏大于非生物过程.
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An in-situ modified sol-gel method for the preparation of a Ni-based monolith-supported catalyst is reported. With the presence of a proper amount of plasticizer and binder, and at an optimized pH value, the stable boehmite sol was modified with metal ions (Ni, Li, La) successfully without distinct growth of the particle size. Monolith-supported Ni-based/gamma-Al2O3 catalysts were obtained using the modified sol as the coating medium with several cycles of dip-coating and calcination. Combined BET, SEM-EDS, XRD and H-2-TPR investigations demonstrated that the derived monolith catalysts had a high specific surface area, a relatively homogeneous surface composition, and a high extent of interaction between the active component and the support. These catalysts showed relatively stable catalytic activities for partial oxidation of methane (POM) to syngas under atmospheric pressure. The monolith catalysts prepared by this sol-gel method also demonstrated an improved resistance to sintering and loss of the active component during the reaction process.
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2009
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Grattan, J. Durand, M. Taylor, S., Illness and elevated Human Mortality in Europe Coincident with the Laki fissure eruption. In: 'Volcanic Degassing: Geological Society, Special Publication 213', Oppenheimer, C., Pyle, D.M. and Barclay, J. (eds). Geological Society, London, Special Publications, 410-414, 2003.
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Grattan, J. Pollution and paradigms: Lessons from Icelandic volcanism for continental flood basalt studies. Lithos. 2005. 79 pp 343-353
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Biblioteki pełnią różnorodne funkcje we współczesnym otoczeniu społecznym. Uczestniczą w tworzeniu kapitału intelektualnego i społecznego, wpływają na wzrost korzyści ekonomicznych użytkowników i całego społeczeństwa. W artykule omówiono główne podejścia i metody badawcze w zakresie oceny korzyści ekonomicznych płynących z funkcjonowania bibliotek. Skupiono się na metodzie analizy kosztów w stosunku do korzyści (ang. CBA – cost-benefit analysis), metodzie analizy warunkowej (ang. CVM – contigent valuation method), określaniu wartości dodanej dla użytkownika (ang. consumer surplus method) i metodologii oceny stopy wzrostu z inwestycji (ang. ROI – return of investment). Przeanalizowano również różne projekty badań prowadzone na świecie w tym zakresie.
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Tese apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Doutor em Ciências da Informação, especialidade em Jornalismo
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http://www.archive.org/details/missionstoheathe00barnrich
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http://www.archive.org/details/twothousandyears014145mbp
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http://www.archive.org/details/dawnonthehillsof008853mbp
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http://www.archive.org/details/conversionmaoris00macduoft
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http://www.archive.org/details/lifeandworkofrev00lewiiala
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http://www.archive.org/details/callofwatersstud01crowrich
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http://moa.umdl.umich.edu/cgi/sgml/moa-idx?notisid=AAU8319 View book via University of Michigan