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961.
ABSTRACT

The Australian government deregulated the wheat export market in 2008, ending 60 years of statutory wheat marketing by the Australian Wheat Board (AWB). In this article, I explore the discursive shifts which contributed to this change. I adopt a genealogical approach to this research, by collecting and analysing policy documents produced between 1983 and 2012, to understand how truths—such as efficiency, competition and the ‘good farmer’—were constructed and reproduced to facilitate wheat export market deregulation in Australia. Through analysing the case of wheat export market deregulation, and the process by which this shift was made possible, this article contributes more broadly to research examining the neoliberalisation of Australian rural industries, and the discursive construction of norms, values and identities to facilitate these changes.  相似文献   
962.
The western terranes exposed east of the Pan-African suture in western Hoggar (southwest Algeria), are reexamined in the light of new structural, petrologic and by the 40Ar/39Ar laser probe data on metamorphic micas and amphiboles. To the north, the Tassendjanet nappe includes the Paleoproterozoic basement, its Mesoproterozoic cover and mafic rocks representing the roots of a ca. 680 Ma arc overlain by Late Neoproterozoic andesites and volcanic greywackes. The nappe preserved at rather shallow crustal level in the east was emplaced southward (D1a) to southeastward (D2). In the south, two metamorphic suites are distinguished. The Tideridjaouine–Tileouine high-pressure metamorphic belt (T=550–600 °C, P=1.4–1.8 GPa) represents a slab of subducted continental material exposed along the western edge of the In Ouzzal granulite unit interpreted as a microcontinent. Differential exhumation of tectonic slices from the high-pressure belt occurred around 615–600 Ma through a system of west-directed recumbent folds (D1b). The Egatalis high grade belt in the west was intruded by syn-metamorphic gabbro–norite bodies. It includes unretrogressed low-pressure granulite facies rocks (T around 750–800 °C, P0.45 GPa) cooled at a rate of 15°/m.y. between 600 and 580 Ma, and followed by the emplacement of several late-kinematic granitic plutons. Final exhumation of the low-pressure, high-temperature metamorphic rocks, that are not found as pebbles in the molasse, took place in the Late Cambrian. The early and relatively fast cooling of the high-pressure and high-temperature metamorphic rocks of the southern part of the Tassendjanet terrane is at variance with the slow cooling of central Hoggar where repeated magmatic activity as young as Late Cambrian occurred [Lithos 45 (1998) 245].  相似文献   
963.
The relation between the magnitude of a flood event and the resulting environmental impacts remains unclear. This study examines the impact of the flood of record on heavy metal deposition on the Tar River floodplain in eastern North Carolina, USA. Samples of sediment deposited on the floodplain following Hurricane Floyd were collected from 85 sites along the lower Tar River basin and analyzed for heavy metal concentration. The Hurricane Floyd event is the flood of record for the Tar River basin. Despite the magnitude of the flood, little suspended sediment was deposited on the floodplain. In almost all cases the deposition was less than 0.2 cm. There was variability in heavy metal content from site to site, but the overall concentrations were lower than might be expected for a flood of the magnitude of Floyd. To aid in comparison of contamination levels, the heavy metal concentrations were normalized to two environmental standards; the EPA preliminary remediation goals for residential soil and the general background concentrations of stream sediments throughout the Tar River basin. Most samples were highly enriched in heavy metals relative to the background concentration of stream sediments. However, samples were generally not contaminated relative to EPA PRG regulations. Arsenic, which was significantly elevated in nearly all samples, was the only exception. This contradiction makes it clear that the standard to which contaminants are compared must be considered carefully. The overall low concentration of heavy metals was likely the result of smaller flooding from Hurricane Dennis, 10 days prior to Hurricane Floyd, moving most of the stored sediment out of the basin prior to wide-spread overtopping of the banks. The implication is that event sequencing is as important as flood magnitude when examining environmental impacts.  相似文献   
964.
The article presents a method to derive synthetic flow logs from low rate injection tests in wells, which are otherwise not accessible for logging. The tests were carried out in the 5 km deep geothermal well GPK2 in the Enhanced Geothermal System (EGS) project of Soultz-sous-Forêts (France) and were aimed at characterizing the status of the well before chemical treatments. The method consists of injecting water at constant flow rates into the well initially filled with brine. The wellhead pressure record of this test is transformed into log of the flow velocity versus depth by a technique described in the paper. Applying this method to borehole GPK2, three outlets could be detected and quantified within the cased and uncased section of this borehole. The outlet in the cased section at 3860 m absorbed 15% of the total flow. This depth corresponds to a known casing restriction, which makes the borehole inaccessible for logging operations. The two other outlets are at the casing shoe at 4420 m (15%) and at 4670 m (70%).  相似文献   
965.
Pumping tests carried out in the fissured layer of a granitic hard-rock aquifer, interpreted at the observation wells by means of the analytical solution of Neuman and at the pumping wells with that of Gringarten show the existence of a strong vertical anisotropy of this layer of the aquifer; the horizontal permeability is clearly and systematically higher than the vertical one. These results agree perfectly with the geological observations, the fissured layer of the weathered granite profile showing the existence of many sub-horizontal fissures. It confirms that, within the fissured layer, the permeability of sub-horizontal fissures due to the weathering process dominates over that of sub-vertical fissures of tectonic origin. To cite this article: J.-C. Maréchal et al., C. R. Geoscience 335 (2003).To cite this article: J.-C. Maréchal et al., C. R. Geoscience 335 (2003).  相似文献   
966.
A petrography–geochemistry-based evaluation of the provenance of the sandstones of the Tertiary Middle Siwalik Subgroup in the Lish River Valley, West Bengal, is presented. The framework grains in the sandstones suggest mixing of sediments from spatially separated gneissic, quartzitic and phyllitic source rocks. Modal values of different framework minerals suggest that recycled sediments in an orogenic setting were deposited in the Middle Siwalik basin in the area. The major and trace element ratios suggest dominantly felsic input and mixing with subordinate basic material in an upper continental crustal setup. The major and trace element data also indicate that rocks of a passive margin setting acted as the source to the sediments. The present paper postulates that the Middle Siwalik sediments were derived from pre-Himalayan gneissic and metabasic rocks of an erstwhile passive margin setting and presently forming the Higher and Lesser Himalaya, respectively.  相似文献   
967.
We consider the definitions and resulting equations of motion for the Lagrangian orbital elements associated with conventional osculating orbit theory for central forces. The analysis indicates that the definitions themselves lead to difficulties which are most apparent in the circular limit. An alternate set of defining relations is presented which eliminates the problems associated with osculating elements. The remaining equation of motion based on these new definitions is reduced to quadratures. This solution completely expresses the orbits for central force problems with no restriction on the eccentricity. Both bounded and open orbits are considered. A generalized Laplace-Runge-Lenz vector is developed and a number of example solutions are presented.  相似文献   
968.
Sediment connectivity characterizes the physical transfer of sediment through different geomorphic compartments in catchments due to sediment detachment, transport and deposition. Quantifying and modelling sediment connectivity is therefore a key prerequisite to improving our understanding of the dispersion of particle‐borne contaminants, especially in catchments exposed to highly erosive climates. The objective of this study is to provide novel insights into typhoon impacts on sediment connectivity from hillslopes to rivers. The dispersion of particle‐bound caesium‐137 (137Cs) was investigated in two coastal catchments draining the main contamination plume from the Fukushima Daiichi Nuclear Power Plant accident. Five sampling campaigns were carried out from November 2011 to November 2015, after each typhoon season. The spatial and temporal evolution of 137Cs contamination was investigated through the calculation of 137Cs enrichment ratios in sediment relative to nearby soils. Rainfall erosivity (EI30) associated with the main typhoons that occurred prior to each sampling campaign were computed, mapped, and finally used to improve a topographic‐based index of connectivity. From 2011 to 2015, mean contamination levels in Mano and Niida catchments decreased from 11.9 kBq kg?1 to 3.3 kBq kg?1 and from 34.1 kBq kg?1 to 8.0 kBq kg?1, respectively. Regional mean EI30 ranged from 262 MJ mm ha?1 h?1 for typhoon Jelawat (in 2012) to 1695 MJ mm ha?1 h?1 for typhoon Roke (in 2011). Typhoons Roke (2011) and Etau (2015) showed the highest connectivity from contaminated sources to the rivers, and induced a significant export of sediment to the ocean. In 2013 a slight increase in 137Cs levels in river sediments occurred, likely resulting from initial decontamination works and the occurrence of two consecutive typhoons. Importantly, this research provides new insights into the connectivity of the main sources of sediments contaminated with radiocaesium in Fukushima Prefecture and their temporal evolution, which will help with ongoing decontamination efforts. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
969.
Groundwater discharge is increasingly recognized as a significant source of nutrient input to coastal waters, relative to surface water inputs. There remains limited information, however, on the extent to which nutrients and organic matter from each of these two flowpaths influence the functional responses of coastal microbial communities. As such, this study determined dissolved organic carbon (DOC) and nutrient concentrations of surface water runoff and groundwater from both an urbanized and a relatively pristine forested drainage basin near Myrtle Beach, South Carolina, and quantified the changes in production rates and biomass of phytoplankton and bacterioplankton in response to these inputs during two microcosm incubation experiments (August and October, 2011). Rainwater in the urbanized basin that would otherwise enter the groundwater appeared to be largely rerouted into the surface flowpath by impervious surfaces, bypassing ecosystem buffers and filtration mechanisms. Surface runoff from the developed basin was most enriched in nutrients and DOC and yielded the highest production rates of the various source waters upon addition to coastal waters. The metabolic responses of phytoplankton and bacterioplankton were generally well predicted as a function of initial chemical composition of the various source waters, though more so with bacterial production. Primary and bacterial productivities often correlated at reciprocal time points (24-h measurement of one with the 72-h measurement of the other). These results suggest human modification of coastal watersheds enhances the magnitude of dissolved constituents delivered to coastal waters as well as alters their distributions between surface and groundwater flowpaths, with significant implications for microbial community structure and function in coastal receiving waters.  相似文献   
970.
Dextral-slip in the Nyainqentangiha region of Tibet resulted in oblique underthrusting and granite generation in the Early to Middle Miocene, but by the end of the epoch uplift and extensional faulting dominated. The east-west dextral-slip Gangdise fault system merges eastward into the northeast-trending, southeast-dipping Nyainqentangiha thrust system that swings eastward farther north into the dextral-slip North Damxung shear zone and Jiali faults. These faults were took shape by the Early Miocene, and the large Nyainqentangiha granitic batholith formed along the thrust system in 18.3-11.0 Ma as the western block drove under the eastern one. The dextral-slip movement ended at -11 Ma and the batholith rose, as marked by gravitational shearing at 8.6-8.3 Ma, and a new fault system developed. Northwest-trending dextral-slip faults formed to the northwest of the raisen batholith, whereas the northeast-trending South Damxung thrust faults with some sinistral-slip formed to the southeast. The latter are replaced farther to the east by the west-northwest-trending Lhunzhub thrust faults with dextral-slip. This relatively local uplift that left adjacent Eocene and Miocene deposits preserved was followed by a regional uplift and the initiation of a system of generally north-south grabens in the Late Miocene at -6.5 Ma. The regional uplift of the southern Tibetan Plateau thus appears to have occurred between 8.3 Ma and 6.5 Ma. The Gulu, Damxung-Yangbajain and Angan graben systems that pass east of the Nyainqentangiha Mountains are locally controlled by the earlier northeast-trending faults. These grabens dominate the subsequent tectonic movement and are still very active as northwest-trending dextral-slip faults northwest of the mountains. The Miocene is a time of great tectonic change that ushered in the modern tectonic regime.  相似文献   
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