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831.
Zhang Guanglei Ranjith P. G. Perera M. S. A. Lu Yiyu Choi Xavier 《Natural Resources Research》2019,28(4):1639-1660
Natural Resources Research - High-volatile bituminous coal samples were reacted in deionized water with supercritical CO2 (ScCO2–water) under simulated in situ pressure and temperature... 相似文献
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Miquel Poyatos‐Mor George D. Jones Rufus L. Brunt Daniel E. Tek David M. Hodgson Stephen S. Flint 《Basin Research》2019,31(5):920-947
Exhumed basin margin‐scale clinothems provide important archives for understanding process interactions and reconstructing the physiography of sedimentary basins. However, studies of coeval shelf through slope to basin‐floor deposits are rarely documented, mainly due to outcrop or subsurface dataset limitations. Unit G from the Laingsburg depocentre (Karoo Basin, South Africa) is a rare example of a complete basin margin scale clinothem (>60 km long, 200 m‐high), with >10 km of depositional strike control, which allows a quasi‐3D study of a preserved shelf‐slope‐basin floor transition over a ca. 1,200 km2 area. Sand‐prone, wave‐influenced topset deposits close to the shelf‐edge rollover zone can be physically mapped down dip for ca. 10 km as they thicken and transition into heterolithic foreset/slope deposits. These deposits progressively fine and thin over tens of km farther down dip into sand‐starved bottomset/basin‐floor deposits. Only a few km along strike, the coeval foreset/slope deposits are bypass‐dominated with incisional features interpreted as minor slope conduits/gullies. The margin here is steeper, more channelized and records a stepped profile with evidence of sand‐filled intraslope topography, a preserved base‐of‐slope transition zone and sand‐rich bottomset/basin‐floor deposits. Unit G is interpreted as part of a composite depositional sequence that records a change in basin margin style from an underlying incised slope with large sand‐rich basin‐floor fans to an overlying accretion‐dominated shelf with limited sand supply to the slope and basin floor. The change in margin style is accompanied with decreased clinoform height/slope and increased shelf width. This is interpreted to reflect a transition in subsidence style from regional sag, driven by dynamic topography/inherited basement configuration, to early foreland basin flexural loading. Results of this study caution against reconstructing basin margin successions from partial datasets without accounting for temporal and spatial physiographic changes, with potential implications on predictive basin evolution models. 相似文献
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J. M. Ade-Hall M. A. Khan P. Dagley R. L. Wilson 《Geophysical Journal International》1968,16(4):389-399
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Polyan PM 《Soviet geography》1982,23(10):707-718
The study of urban agglomerations in the USSR is discussed, with a focus on their basic framework and role in settlement and on the various techniques used to define such agglomerations. "The present paper envisages a minimum population of 250,000 for the core city (or cities), maximum travel time of 1.5 to 2 hours to the core city, and a minimum value for a 'development coefficient' reflecting the population of the agglomeration and its structure in terms of urban places. The networks of agglomerations that existed at the time of the 1959 and 1970 censuses are analyzed and compared. The urban agglomerations are grouped into five classes of development levels and into three classes of growth rates. Intensive and extensive growth factors are discussed." 相似文献
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