978 resultados para Co(II)
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The diffraction pattern of Fe3O4 (not shown) confirmed the presence of only one phase, corresponding to magnetite with a lattice parameter a = 8.357 Å and a crystallite size of 16.6 ± 0.2 nm. The diffraction pattern of MGNC (not shown) confirmed the presence of a graphitic phase, in addition to the metal phase, suggesting that Fe3O4 nanoparticles were successfully encapsulated within a graphitic structure during the synthesis of MGNC. The core-shell structure of MGNC is unequivocally demonstrated in the TEM micrograph shown in Fig. 1b. Characterization of the MGNC textural and surface chemical properties revealed: (i) stability up to 400 oC under oxidizing atmosphere; (ii) 27.3 wt.% of ashes (corresponding to the mass fraction of Fe3O4); (iii) a micro-mesoporous structure with a fairly well developed specific surface area (SBET = 330 m2 g-1); and (iv) neutral character (pHPZC = 7.1). In addition, the magnetic nature of MGNC (Fig. 2) is an additional advantage for possible implementation of in situ magnetic separation systems for catalyst recovery.
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The Centre for Eastern Studies has decided to embark on the project entitled 'Turkey after the start of negotiations with the European Union - foreign relations and the domestic situation' for two major reasons: the start of the accession negotiations between Ankara and the European Union in October 2005, and the significant part which Turkey plays in western Eurasia (the Caucasus, the countries in the basins of the Black and Caspian Seas, the Middle East and the Balkans) which We wish to present our readers our second report discussing Turkey's relations with Central Asia, the Caucasus and Russia, the aspect of Turkish foreign policy regarding the Black Sea, and the role of Turkey as a transit country for oil and gas from the Middle East and the Caspian regions. The evaluation of Turkey's standpoint and potential regarding the aforementioned issues is especially important, considering the tensions existing in Turkey's relations with the EU and the USA, as well as the West's increasing engagement in the Caucasus, Central Asia and Black Sea regions. In this process, Ankara may play the role of a significant ally for the West. However, it may just as readily play the role of its rival, who could co-operate with other countries and may seriously frustrate the implementation of the EU and US' goals. The Report was developed between autumn 2006 and autumn 2007, over which time the project participants searched for publicly available documents in Poland, Turkey, EU countries and the USA, and went on five research trips to Central Asia, Russia, Turkey and Caucasus, where they met local analysts, officials and researchers.
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We present new δ¹³C measurements of atmospheric CO₂ covering the last glacial/interglacial cycle, complementing previous records covering Terminations I and II. Most prominent in the new record is a significant depletion in δ¹³C(atm) of 0.5‰ occurring during marine isotope stage (MIS) 4, followed by an enrichment of the same magnitude at the beginning of MIS 3. Such a significant excursion in the record is otherwise only observed at glacial terminations, suggesting that similar processes were at play, such as changing sea surface temperatures, changes in marine biological export in the Southern Ocean (SO) due to variations in aeolian iron fluxes, changes in the Atlantic meridional overturning circulation, upwelling of deep water in the SO, and long-term trends in terrestrial carbon storage. Based on previous modeling studies, we propose constraints on some of these processes during specific time intervals. The decrease in δ¹³C(atm) at the end of MIS 4 starting approximately 64 kyr B.P. was accompanied by increasing [CO₂]. This period is also marked by a decrease in aeolian iron flux to the SO, followed by an increase in SO upwelling during Heinrich event 6, indicating that it is likely that a large amount of δ¹³C-depleted carbon was transferred to the deep oceans previously, i.e., at the onset of MIS 4. Apart from the upwelling event at the end of MIS 4 (and potentially smaller events during Heinrich events in MIS 3), upwelling of deep water in the SO remained reduced until the last glacial termination, whereupon a second pulse of isotopically light carbon was released into the atmosphere.
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Continued by the author's: Some account of domestic architecture in England from Richard II. to Henry VIII.
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Mode of access: Internet.
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Bibliography: p. 570-577.
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Bibliography: p. 266-276.
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Errata and advertisement for "New England Depot. D.L. Hale" at end of v. 2.
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Poem "The colours" by E. Van Blon, part 2, p. [65]-66.
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"Supported in part by Contract AT(11-1)-1018 with the U.S. Atomic Energy Commission and the Advanced Research Projects Agency."
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Mode of access: Internet.
The history of Enniskillen with reference to some manors in co. Fermanagh, and other local subjects,
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Part of the plates are printed on both sides.
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Signed on page ii: Frank M. Swacker, chairman, Hugh B. Fouke, member, Sidney St. F. Thaxter, member.