869 resultados para 010201 Approximation Theory and Asymptotic Methods
Resumo:
Two gravity cores retrieved off NW Africa at the border of arid and subtropical environments (GeoB 13602-1 and GeoB 13601-4) were analyzed to extract records of Late Quaternary climate change and sediment export. We apply End Member (EM) unmixing to 350 acquisition curves of isothermal remanent magnetization (IRM). Our approach enables to discriminate rock magnetic signatures of aeolian and fluvial material, to determine biomineralization and reductive diagenesis. Based on the occurrence of pedogenically formed magnetic minerals in the fluvial and aeolian EMs, we can infer that goethite formed in favor to hematite in more humid climate zones. The diagenetic EM dominates in the lower parts of the cores and within a thin near-surface layer probably representing the modern Fe**2+/Fe**3+ redox boundary. Up to 60% of the IRM signal is allocated to a biogenic EM underlining the importance of bacterial magnetite even in siliciclastic sediments. Magnetosomes are found well preserved over most of the record, indicating suboxic conditions. Temporal variations of the aeolian and fluvial EMs appear to faithfully reproduce and support trends of dry and humid conditions on the continent. The proportion of aeolian to fluvial material was dramatically higher during Heinrich Stadials, especially during Heinrich Stadial 1. Dust export from the Arabian-Asian corridor appears to vary contemporaneous to increased dust fluxes on the continental margin of NW Africa emphasizing that melt-water discharge in the North Atlantic had an enormous impact on atmospheric dynamics.
Resumo:
Advertisments on last page.
Resumo:
Mode of access: Internet.
Resumo:
Bibliography: p. 185-196.
Resumo:
Mode of access: Internet.
Resumo:
Introduction: Dominant ideas of modern study: unity, induction, evolution.--book I. Literary morphology: varieties of literature and their underlying principles.--book II. The field and scope of literary study.--book III. Literary evolution as reflected in the history of world literature.--book IV. Literary criticism: the traditional confusion and the modern reconstruction.--book V. Literature as a mode of philosophy.--book VI. Literature as a mode of art. Conclusion: the traditional and the modern study of literature. Syllabus. Works of the author. General index. Seventh impression, June, 1928
Resumo:
"Of the two books included in this volume, the first, entitled Theory of history, was originally published by the Yale university press in 1925; the second, The processes of history, was likewise issued by the Yale university press, but in 1918."-Pref.
Resumo:
Includes bibliography.
Resumo:
Bibliography: leaves [87]-[88]
Resumo:
Mode of access: Internet.
Resumo:
Mode of access: Internet.
Resumo:
Federal Highway Administration, Washington, D.C.
Resumo:
Mode of access: Internet.