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G. L. Macpherson R. C. Capo B. W. Stewart T. T. Phan K. Schroeder R. W. Hammack 《Geofluids》2014,14(4):419-429
Lithium (Li) concentrations of produced water from unconventional (horizontally drilled and hydraulically fractured shale) and conventional gas wells in Devonian reservoirs in the Appalachian Plateau region of western Pennsylvania range from 0.6 to 17 mmol kg?1, and Li isotope ratios, expressed as in δ7Li, range from +8.2 to +15‰. Li concentrations are as high as 40 mmol kg?1 in produced waters from Plio‐Pleistocene through Jurassic‐aged reservoirs in the Gulf Coast Sedimentary Basin analyzed for this study, and δ7Li values range from about +4.2 to +16.6‰. Because of charge‐balance constraints and rock buffering, Li concentrations in saline waters from sedimentary basins throughout the world (including this study) are generally positively correlated with chloride (Cl), the dominant anion in these fluids. Li concentrations also vary with depth, although the extent of depth dependence differs among sedimentary basins. In general, Li concentrations are higher than expected from seawater or evaporation of seawater and therefore require water–mineral reactions that remove lithium from the minerals. Li isotope ratios in these produced waters vary inversely with temperature. However, calculations of temperature‐dependent fractionation of δ7Li between average shale δ7Li (?0.7‰) and water result in δ7Liwater that is more positive than that of most produced waters. This suggests that aqueous δ7Li may reflect transport of water from depth and/or reaction with rocks having δ7Li lighter than average shale. 相似文献
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Revisiting the theoretical roots of the key concepts of “embeddedness” and “networks” that underpin many recent regional innovation polices, this paper strives to achieve a more systematic understanding of the overall network structure of geographic agglomerations, which helps to form a more convincing model of regional development based on learning. This also helps to establish an analytical framework with indicators to assess the overall network structure in regional innovation policies. Employing the framework, the examination of cluster policy in the West Midlands highlights its weakness in addressing the overall cluster network structure and the contingent factors influencing the structure. The analysis suggests that there may be similar weaknesses in other regional innovation policies and the theories underpinning them as they share a common weakness in addressing the structural characteristics of overall networks. 相似文献
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John R.M. Stewart Richard B. Allen Andrew K.G. Jones Kirsty E.H. Penkman Matthew J. Collins 《Journal of archaeological science》2013
Avian eggshell is a common component of many archaeological deposits, but its archaeological potential remains largely unexplored. The most obvious reasons are two-fold. Firstly, despite its abundance on many sites, eggshell is often overlooked during excavation. Even when it is recovered, small fragmented remains are difficult to identify taxonomically. Here we introduce a minimally destructive qualitative analytical technique for taxonomic identification of eggshell fragments based on highly sensitive mass spectrometry and peptide mass fingerprinting (ZooMS), and illustrate its application to eggshell recovered from the Viking Age urban site at Hungate, York. We adopt a more extreme version of the method of bleach treating used to prepare ancient eggshell for DNA analysis, followed by conventional peptide mass fingerprinting using MALDI-ToF mass spectrometry. The development of this technique will allow future research to make better use of eggshell fragments recovered from archaeological sites. 相似文献
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Kieran Stewart 《European Legacy》2015,20(4):349-359
Despite the widespread influence of Nietzsche’s iconoclastic works on twentieth-century intellectual and literary culture, there has been a surprising lack of academic focus on the parallels between his philosophical trajectory and the anthropological literature on the mysterious god Dionysus. The striking correlations between ancient Dionysian worship with Nietzsche’s oeuvre revalorise the celebration of ecstasy. In Twilight of the Idols, he states that the Dionysian is “beyond pity and terror, to realize in oneself the eternal joy of becoming.” By elucidating some of the mysteries surrounding this enigmatic god, this article aims to re-establish the central importance of Dionysus in Nietzsche’s work, and to suggest that if we are to understand Nietzsche at all, we must first undertake an anthropological reading of Dionysus. 相似文献
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Jeroen C. J. H. Aerts Erwin Eisinger Gerard B. M. Heuvelink Theodor J. Stewart 《Geographical analysis》2003,35(2):148-169
Research in the area of spatial decision support (SDS) and resource allocation has recently generated increased attention for integrating optimization techniques with GIS. In this paper we address the use of spatial optimization techniques for solving multi‐site land‐use allocation (MLUA) problems, where MLUA refers to the optimal allocation of multiple sites of different land uses to an area. We solve an MLUA problem using four different integer programs (IP), of which three are linear integer programs. The IPs are formulated for a raster‐based GIS environment and are designed to minimize development costs and to maximize compactness of the allocated land use. The preference for either minimizing costs or maximizing compactness has been made operational by including a weighting factor. The IPs are evaluated on their speed and their efficacy for handling large databases. All four IPs yielded the optimal solution within a reasonable amount of time, for an area of 8 × 8 cells. The fastest model was successfully applied to a case study involving an area of 30 × 30 cells. The case study demonstrates the practical use of linear IPs for spatial decision support issues. 相似文献
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