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Exploratory variography was used to examine the spatial continuity of water–well yields in the Pinardville 7 Minute Quadrangle in southern New Hampshire and to link the variography to the characteristics of the fractured igneous and metamorphic rocks within the aquifer system. In addition to the analyses of variograms computed by using data from 939 wells, analyses were performed on subsets of the data that were stratified according to the level of yield and to five rock types. The stratification according to yield was defined by using the industry standard of a high-yield well that produces 40 gallons per minute or more. The stratification of the low-yield wells by rock type was defined by using the classification on the bedrock map for the State of New Hampshire. Although the variability is high in the low-yield wells, as indicated by the large nugget value, overall continuity ranges to 6000 feet in the fracture zones in which these wells have been drilled. This continuity is dominant in the northwesterly direction, as indicated by the directional variography. This result is consistent with the general trend in the larger tectonic configuration of the region. A lack of spatial correlation for 81 high-yield wells is consistent with the geologic interpretation that these wells occur in locally determined configurations of sheeting and steeply dipping fractures. Yield data in only three of the five rock types were sufficient for variography. Within these three, the dominant direction of the correlation structure ranged from northwesterly for the Massabesic Gneiss Complex to northeasterly for the Rangeley Formation to northerly for the Spaulding Granite, where the signature of the continuity in the low-yield wells is predominately attributed to the fracture system.  相似文献   
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Using the Planetary Camera on board the Hubble Space Telescope , we have measured the projected separation of the binary components in the nucleus of the planetary nebula Abell 35 to be larger than 0.08 arcsec but less than 0.14 arcsec. The system has been imaged in three filters centred at 2950, 3350 and 5785 Å. The white dwarf primary star responsible for ionizing the nebula is half as bright as its companion in the 2950-Å filter, causing the source to be visibly elongated. The 3350-Å setting, on the other hand, shows no elongation as a result of the more extreme flux ratio. The F300W data allow the determinination of the projected separation of the binary. At the minimum distance of 160 pc to the system, our result corresponds to 18 ± 5 au. This outcome is consistent with the wind accretion induced rapid rotation hypothesis, but cannot be reconciled with the binary having emerged from a common-envelope phase.  相似文献   
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Drew Whitelegg 《Area》2002,34(2):128-138
This paper argues that intra –regional competition is as important as intra –regional in the shaping of an urban region. Recent concentration on urban promotion within the discipline places an emphasis on competition between cities that should be counterbalanced by stressing the degree of competition between cities and their suburban peripheries. Using the case of Atlanta, Georgia, and in particular its Vision 2020 initiative, the paper explores how regionalist approaches can easily unravel due to continued rivalries from individual constituents. Placing its theoretical grounding within David Harvey's notion of 'structural coherence', the paper argues that regional policies within a capitalist environment of uneven development tend towards only temporary solutions.  相似文献   
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Sustaining a developed economy and expanding a developing one require the use of large volumes of natural aggregate. Almost all human activity (commercial, recreational, or leisure) is transacted in or on facilities constructed from natural aggregate. In our urban and suburban worlds, we are almost totally dependent on supplies of water collected behind dams and transported through aqueducts made from concrete. Natural aggregate is essential to the facilities that produce energy—hydroelectric dams and coal-fired powerplants. Ironically, the utility created for mankind by the use of natural aggregate is rarely compared favorably with the environmental impacts of mining it. Instead, the empty quarries and pits are seen as large negative environmental consequences. At the root of this disassociation is the philosophy of environmentalism, which flavors our perceptions of the excavation, processing, and distribution of natural aggregate. The two end-member ideas in this philosophy are ecocentrism and anthropocentrism. Ecocentrism takes the position that the natural world is a organism whose arteries are the rivers—their flow must not be altered. The soil is another vital organ and must not be covered with concrete and asphalt. The motto of the ecocentrist is man must live more lightly on the land. The anthropocentrist wants clean water and air and an uncluttered landscape for human use. Mining is allowed and even encouraged, but dust and noise from quarry and pit operations must be minimized. The large volume of truck traffic is viewed as a real menace to human life and should be regulated and isolated. The environmental problems that the producers of natural aggregate (crushed stone and sand and gravel) face today are mostly difficult social and political concerns associated with the large holes dug in the ground and the large volume of heavy truck traffic associated with quarry and pit operations. These concerns have increased in recent years as society's demand for living space has encroached on the sites of production; in other words, the act of production has engendered condemnation. Many other environmental problems that are associated with dust and noise and blasting from quarry and pit operations have been reduced through the efficient use of technology. Recycling concrete in buildings, bridges, and roads and asphaltic pavements will ultimately reduce the demand for virgin natural aggregate. The impact created by the large holes in the ground required for the mining of natural aggregate can be greatly reduced by planning their reclamation before mining begins.  相似文献   
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