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Krogstad EJ Balakrishnan S Mukhopadhyay DK Rajamani V Hanson GN 《Science (New York, N.Y.)》1989,243(4896):1337-1340
The Archean Kolar Schist Belt, south India, is a suture zone where two gneiss terranes and at least two amphibolite terranes with distinct histories were accrted. Amphibolites from the eastern and western sides of the schist belt have distinct incompatible element and isotopic characteristics sugesting that their volcanic protoliths were derived from dint mantle sources. The amphibolite and gneiss terranes were juxtaposed by horizontal compression and shearing between 2530 and 2420 million years ago (Ma) along a zone marked by the Kolar Schist Belt. This history of accretion of discrete crustal terranes resembles those of Phanerozoic convergent margins and thus suggests that plate tectonics operated on Earth by 2500 Ma. 相似文献
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Bloch ED Queen WL Krishna R Zadrozny JM Brown CM Long JR 《Science (New York, N.Y.)》2012,335(6076):1606-1610
The energy costs associated with large-scale industrial separation of light hydrocarbons by cryogenic distillation could potentially be lowered through development of selective solid adsorbents that operate at higher temperatures. Here, the metal-organic framework Fe(2)(dobdc) (dobdc(4-) : 2,5-dioxido-1,4-benzenedicarboxylate) is demonstrated to exhibit excellent performance characteristics for separation of ethylene/ethane and propylene/propane mixtures at 318 kelvin. Breakthrough data obtained for these mixtures provide experimental validation of simulations, which in turn predict high selectivities and capacities of this material for the fractionation of methane/ethane/ethylene/acetylene mixtures, removal of acetylene impurities from ethylene, and membrane-based olefin/paraffin separations. Neutron powder diffraction data confirm a side-on coordination of acetylene, ethylene, and propylene at the iron(II) centers, while also providing solid-state structural characterization of the much weaker interactions of ethane and propane with the metal. 相似文献
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