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排序方式: 共有993条查询结果,搜索用时 15 毫秒
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Andrzej P. Radliński Tara L. Busbridge Evan Mac A. Gray Tomasz P. Blach David J. Cookson 《International Journal of Coal Geology》2009,77(1-2):80-89
Time- and position-resolved synchrotron small angle X-ray scattering data were acquired from samples of two Australian coal seams: Bulli seam (Bulli 4, Ro = 1.42%, Sydney Basin), which naturally contains CO2 and Baralaba seam (Ro = 0.67%, Bowen Basin), a potential candidate for sequestering CO2. This experimental approach has provided unique, pore-size-specific insights into the kinetics of CO2 sorption in the micro- and small mesopores (diameter 5 to 175 Å) and the density of the sorbed CO2 at reservoir-like conditions of temperature and hydrostatic pressure.For both samples, at pressures above 5 bar, the density of CO2 confined in pores was found to be uniform, with no densification in near-wall regions. In the Bulli 4 sample, CO2 first flooded the slit pores between polyaromatic sheets. In the pore-size range analysed, the confined CO2 density was close to that of the free CO2. The kinetics data are too noisy for reliable quantitative analysis, but qualitatively indicate faster kinetics in mineral-matter-rich regions.In the Baralaba sample, CO2 preferentially invaded the smallest micropores and the confined CO2 density was up to five times that of the free CO2. Faster CO2 sorption kinetics was found to be correlated with higher mineral matter content but, the mineral-matter-rich regions had lower-density CO2 confined in their pores. Remarkably, the kinetics was pore-size dependent, being faster for smaller pores.These results suggest that injection into the permeable section of an interbedded coal-clastic sequence could provide a viable combination of reasonable injectivity and high sorption capacity. 相似文献
256.
Mariusz Majdański 《Acta Geophysica》2012,60(1):59-75
A precise 3D model of the crust is necessary to start any tectonic or geodynamic interpretation. It is also essential for
seismic interpretations of structures lying below as well as for correct analysis of shallow structures using reflection seismics.
During the last decades, a number of wide-angle refraction experiments were performed on the territory of central and eastern
Europe (POLONAISE’97, CELEBRATION 2000, SUDETES 2003), resulting in many high quality 2D models. It is an interesting and
complicated transition zone between Precambrian and Palaeozoic Platforms. This paper presents 3D model of the velocity distribution
in the crust and upper mantle interpolated from 2D models of the structure along 33 profiles. The obtained model extends to
a depth of 50 km and accurately describes the main features of the crustal structures of Poland and surrounding areas. Different
interpolation techniques (Kriging, linear) are compared to assure maximum precision. The final model with estimated uncertainty
is an interesting reference of the area for other studies. 相似文献
257.
Mark F. A. Furze James D. Scourse Anna J. Pieńkowski Fabienne Marret William O. Hobbs Rosemary A. Carter Brian T. Long 《Boreas: An International Journal of Quaternary Research》2014,43(1):149-174
Recent work on the last glaciation of the British Isles has led to an improved understanding of the nature and timing of the retreat of the British?Irish Ice Sheet (BIIS) from its southern maximum (Isles of Scilly), northwards into the Celtic and Irish seas. However, the nature of the deglacial environments across the Celtic Sea shelf, the extent of subaerial exposure and the existence (or otherwise) of a contiguous terrestrial linkage between Britain and Ireland following ice retreat remains ambiguous. Multiproxy research, based on analysis of 12 BGS vibrocores from the Celtic Deep Basin (CDB), seeks to address these issues. CDB cores exhibit a shell‐rich upward fining sequence of Holocene marine sand above an erosional contact cut in laminated muds with infrequent lonestones. Molluscs, in situ Foraminifera and marine diatoms are absent from the basal muds, but rare damaged freshwater diatoms and foraminiferal linings occur. Dinoflagellate cysts and other non‐pollen palynomorphs evidence diverse, environmentally incompatible floras with temperate, boreal and Arctic glaciomarine taxa co‐occurring. Such multiproxy records can be interpreted as representing a retreating ice margin, with reworking of marine sediments into a lacustrine basin. Equally, the same record may be interpreted as recording similar conditions within a semi‐enclosed marine embayment dominated by meltwater export and deposition of reworked microfossils. As assemblages from these cores contrast markedly with proven glaciomarine sequences from outside the CDB, a glaciolacustrine interpretation is favoured for the laminated sequence, truncated by a Late Weichselian transgressive sequence fining upwards into fully marine conditions. Reworked rare intertidal molluscs from immediately above the regional unconformity provide a minimum date c. 13.9 cal. ka BP for commencement of widespread marine erosion. Although suggestive of glaciolacustrine conditions, the exact nature and timing of laminated sediment deposition within the CDB, and the implications this has on (pen)insularity of Ireland following deglaciation, remain elusive. 相似文献
258.
J. Puziewicz L. Czechowski L. Krysiński J. Majorowicz M. Matusiak-Ma?ek M. Wróblewska 《International Journal of Earth Sciences》2012,101(5):1211-1228
The crustal section beneath amphibolite Nied?wied? Massif (Fore-Sudetic Block in NE Bohemian Massif), modelled on the basis of geological and seismic data, is dominated by gneisses with subordinate granites (upper and middle crust) and melagabbros (lower crust). The geotherm was calculated based on the chemical analyses of the heat-producing elements in the rocks forming the crust and the measurements of their density and heat conductivity. The results were verified by heat flow calculations based on temperature measurements from 1,600?m deep well in the Nied?wied? Massif and by temperature–depth estimates in mantle xenoliths coming from the nearby ca. 4.5?My basanite plug in Lutynia. The paleoclimate-corrected heat flow in the Nied?wied? Massif is 69.5?mW?m?2, and the mantle heat flow is 28?mW?m?2. The mantle beneath the Massif was located marginally relative to the areas of intense Cenozoic thermal rejuvenation connected with alkaline volcanism. This results in geotherm which is representative for lithosphere parts located at the margins of zones of continental alkaline volcanism and at its waning stages. The lithosphere–asthenosphere boundary (LAB) beneath Nied?wied? is located between 90 and 100?km depth and supposedly the rheological change at LAB is not related to the appearance of melt. 相似文献
259.
Włodzimierz Czernuszenko 《Journal of Hydrology》1973,19(3):259-268
The work contains analyses of two cases of stream diffusion under conditions of turbulent flow in an open channel. The analysed cases were: a source of rectangular cross-section placed in the channel axis and at the wall. To describe the mixing process the known equation of the turbulent diffusion was used. Verification of the solution for the considered cases was made based on research performed on models. 相似文献
260.
In the last few hundred years, medium‐high mountain geomorphic systems of the East Sudetes, central Europe, have evolved under varying human impacts and have shown distinctive behaviours, depending on the nature and intensity of human activities. The general trend within this period has been from initial disturbance brought about by the spread of agriculture, through managed rural landscapes in the 19th and early 20th century, to gradual restoration of natural conditions observed in the last few tens of years, concurrent with considerable population decline in the mountain valleys. Accelerated soil erosion was successfully mitigated by the introduction of agricultural terraces in the 19th century, and most sediment could have been stored within the slopes. The current phase of nature restoration is understood as a return to general slope stability, weak coupling between slopes and channels, and limited sediment transfer across and out of mountainous drainage basins, which typified most of the Holocene prior to human colonization. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献