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1.
Earth, Moon, and Planets - 相似文献
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Maarten A. Prins Hongbo Zheng Kay Beets Simon Troelstra Patrick Bacon Ilse Kamerling Wouter Wester Martin Konert Xiangtong Huang Wang Ke Jef Vandenberghe 《第四纪科学杂志》2009,24(1):75-84
The Mangshan Plateau is located on the south bank of the Huang He (Yellow River) just west of the city of Zhengzhou, well outside the Loess Plateau in central China. Mixing models of the grain‐size data indicate that the loess deposits are mixtures of three loess components. Comparison of the mixing model with existing models established for a series of loess–palaeosol sequences from the Loess Plateau indicates that the Mangshan loess has been supplied from a proximal dust source, the Huang He floodplain, during major dust outbreaks. The high accumulation rates, the composition of the loess components, and especially the high proportions of a sandy loess component support this. Owing to the exceptionally high accumulation rates, the Mangshan grain size, magnetic susceptibility and carbonate records provide a high‐resolution archive of environmental and climate change. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Shelf-mounted Ocean Thermal Energy Conversion (OTEC) plants require installation of cold-water pipes (CWP) on slopes of40deg to depths of 1000 m. In addition, tower platforms containing OTEC power systems may be located on lesser sloped terrain near shore and exposed to special environmental loading problems affecting foundation design. Shelf-mounted installations require careful attention to site selection and geotechnical considerations for foundation integrity on sloped surfaces. This paper primarily discusses research associated with cold-water pipe and foundation installations on steep slopes, although research continues on tower platforms located on the shelf. At least five nations are in various stages of development of OTEC systems for island applications. Each of their systems is either shelf mounted or land based and requires that a large diameter cold-water pipe be installed on a steep slope to provide cold water from 1000-m depths. In addition to the installation and deployment of the large cold-water pipe, the most significant problem is the design and installation of suitable foundations that will last for several decades. To date there is very little experience in the offshore industry for large installations on steep slopes. A major scale-model research project is underway on the slopes of the island of Hawaii. A section of pipe 2.4 m in diameter and 24 m long was installed using combination concrete foundations and joints. The pipe and foundations are fully instrumented to measure environmental loading forces due principally to currents and waves. Environmental measurements will also be taken in the test area. The measurement data will be used to validate available analytical models for subsequent use in aiding industry in providing more cost-effective designs for OTEC pipes and foundations. 相似文献
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Angela C. Taylor 《New Astronomy Reviews》2003,47(11-12):925
We discuss two experiments – the Very Small Array (VSA) and the Arcminute MicroKelvin Imager (AMI) – and their prospects for observing the CMB at high angular multipoles. Whilst the VSA is primarily designed to observe primary anisotropies in the CMB, AMI is designed to image secondary anisotropies via the Sunyaev–Zel’dovich effect. The combined ℓ-range of these two instruments is between ℓ=150 and 10,000. 相似文献
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We present warm dark matter (WDM) as a possible solution to the missing satellites and angular momentum problem in galaxy
formation and introduce improved initial conditions for numerical simulations of WDM models, which avoid the formation of
unphysical haloes found in earlier simulations. There is a hint, that because of that the mass function of satellite haloes
has been overestimated so far, pointing to higher values for the WDM particle mass.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献