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681.
C. Vance Haynes T. A. Maxwell A. El Hawary K. A. Nicoll S. Stokes 《Geoarchaeology》1997,12(8):819-832
A small concentration of Acheulian cleavers and handaxes within the driest region on Earth adds to the increasing evidence that the eastern Sahara was considerably more verdant during the Middle Pleistocene than it is today. The similarities to stone artifact assemblages of Acheulian sites in sub-Saharan Africa and in the Levant support the evidence for the movement of hominids, utilizing the Kombewa lithic technology, between Africa and the Middle East during the Middle Pleistocene. © 1997 John Wiley & Sons, Inc. 相似文献
682.
Zhou Jia-jin Gong Xiao-nan Zhang Ri-hong Hesham El Naggar M. Wang Kui-hua 《Acta Geotechnica》2020,15(7):1847-1857
Acta Geotechnica - This paper presents the results of field tests performed to investigate the behavior of pre-bored grouted planted nodular (PGPN) pile embedded in deep clayey soil. The test piles... 相似文献
683.
Shorebirds, as migratory aquatic birds and top predators in intertidal ecosystems, can be affected by global environmental changes and escalations in local impacts on coastal lagoons and estuarine trophic networks. Many shorebirds winter in North African Atlantic coastal sites, most likely because these locations provide constant and reliable food supplies with less energy costs in comparison with the wintering sites of northern Europe. Although more information is available for other important southern coastal sites (e.g. Saharan Atlantic coastal desert and Guinean mangroves coast), very little information is available for the North African Atlantic coast. Here, we focus on the impact of shorebird predation on benthic macroinvertebrates in a major wintering site in this area—Sidi Moussa coastal lagoon, Morocco—using an exclosure experiment. For most of the macroinvertebrate species there was no significant effect of the exclusion of shorebird predation. Overall, our results do not show evidence that predation by shorebirds influenced the overall standing biomass of the benthic community. This may indicate that the benthic productivity is high enough to provide constant and reliable food supplies for non-breeding shorebirds. 相似文献
684.
Al Rashdi Mouza Rashid El Tokhi Mohamed Alaabed Sulaiman El Mowafi Walid Arabi Alya A. 《Natural Resources Research》2020,29(6):4149-4160
Natural Resources Research - Rare earth element (REE) contamination has major consequences for the environment and humans. Some forms of REEs have more serious environmental impacts than others. It... 相似文献
685.
Salah Y. El Beialy Haytham S. El Atfy Michael S. Zavada Essam M. El Khoriby Ramadan H. Abu-Zied 《Marine and Petroleum Geology》2010
The present study of the Abu Roash and Bahariya formations in well GPTSW-7 refines our understanding of the subsurface Cretaceous of the north Western Desert of Egypt. Our investigations are based on the palynological analyses of 71 cuttings samples, of which 24 have also been analyzed for geochemistry, in addition to 3 sidewall cores analyzed for vitrinite reflectance (Ro). 相似文献
686.
687.
Kaolin, cordierite, and calcite are investigated as supports for TiO2. The prepared TiO2/support samples are examined for the removal of organic dyes from wastewater. The samples are preliminarily investigated to identify the optimal loaded system using synthetic wastewater containing methylene blue (MB). Data indicate that the investigated support significantly affects the photocatalytic activity of the supported TiO2. Low photocatalytic activity toward MB degradation is observed upon using TiO2/calcite when compared to the unsupported TiO2. Interaction between calcite and titania species probably occurrs to produce the less photoactive CaTiO3 amorphous species. Anatase TiO2 is obtained upon using kaolin and cordierite as supports. The low photocatalytic performance of the TiO2/kaolin sample is also observed. A high concentration of MB on TiO2/kaolin surfaces blocks the photoactive sites. TiO2/cordierite shows the highest photocatalytic activity compared to the unsupported TiO2 as well as the other TiO2/support samples. Rigid cordierite particles suppress the agglomeration of TiO2 particles during the preparation, leading to a high exposed surface of TiO2 towards light illumination. TiO2/cordierite is investigated for the removal of organic dye from real wastewater collected from a textile dyeing factory. Color removal of up to 46% is achieved upon UV irradiation. 相似文献
688.
The development of industrial and tourism activities as well as the increase in the urban population in the northwest African region has generally been highly concentrated in the coastal zone. Due to high rates of population growth, urbanisation is likely to increase dramatically in the coming future. This paper presents a physical and socio-economic environmental analysis of the region and highlights the few efforts that have called for the development of co-ordinated strategies in view of integrated coastal zone management. Experience in the implementation of methodologies for adopting integrated coastal zone management strategies in these countries is discussed. 相似文献
689.
690.
The Pan-African basement exposed in the Meatiq area west of Quseir, Egypt, consists of an infracrustal basement overthrusted by a supracrustal cover. The infracrustal rocks were developed as a result of an old orogeny referred to as the Meatiqian orogeny where granite—gneiss, migmatitic gneisses and migmatized amphibolites were formed. The granite—gneiss represents a deformed granite pluton emplaced at 626±2 Ma, whereas the migmatitic gneisses and amphibolites are of mixed igneous and sedimentary parentage. In view of the data so far available, the nature of the Meatiqian orogeny could not be deciphered. In spite of the young isotopic ages, it is suggested that at least the metasedimentary gneisses represent older rocks in the stratigraphic sequence of the infracrustal basement.The supracrustal cover represents a part of an extensive ophiolitic mélange obducted onto the infracrustal basement during the next orogeny (Abu Ziran orogeny) which culminated at 613±2 Ma. An active continental margin-type regime can adequately explain the evolution of such a supracrustal cover. During obduction, the ophiolitic mélange and the upper 2 km thick part of the infracrustal basement were intensely deformed and metamorphosed under PT conditions of the greenschist—epidote amphibolite facies. The deformed infracrustal basement was converted into mylonitic—blastomylonitic rocks and schists composing five thrust sheets, and subsequently intruded by synkinematic granitoid sheets. Later, both the infracrustal basement and the overlying supracrustal cover were isostatically uplifted, subjected to complex shallow folding giving rise to the major Meatiq domal structure, and were intruded by a postkinematic adamellite pluton at 579±6 Ma. 相似文献