首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   34篇
  免费   1篇
  2022年   2篇
  2019年   2篇
  2018年   4篇
  2017年   4篇
  2015年   1篇
  2013年   4篇
  2012年   2篇
  2011年   1篇
  2010年   2篇
  2009年   1篇
  2008年   1篇
  2006年   3篇
  2005年   1篇
  2002年   1篇
  2001年   1篇
  1997年   1篇
  1990年   1篇
  1988年   1篇
  1975年   1篇
  1970年   1篇
排序方式: 共有35条查询结果,搜索用时 15 毫秒
1.
2.
The so called Arab Spring has brought more challenges to the security of the Arabian Gulf states members of the Gulf Cooperative Council (GCC). This article aims to reach a better understanding of the main threats facing the GCC states in the post Arab Spring era. It argues that the conservative system of the GCC states, originated in the paternalistic conservatism, is facing an essential threat from three very important elements that are instigated by the eruption of the so called Arab Spring: political liberal ideas, political Islamic movement, and sectarianism. The article investigates the impact of these elements on the GCC states.  相似文献   
3.
The Rabat-Témara region of the Moroccan Atlantic coast reveals a succession of Quaternary palaeobeaches. This coastal area is dotted with numerous prehistoric caves. The study of the Upper Pleistocene coastal landscape associated with these caves is of paramount importance in the knowledge of human population subsistence. During the Upper Pleistocene, the ocean level changes drastically influenced the coastal geomorphology as well as the fauna assemblages. The chrono-lithostratographical analysis of the coastal sedimentary formations allows the distinction of three sequences rich in marine fauna. These sequences date from MIS 11 to MIS 5. The identification of malacofauna species from these deposits revealed 39 species, along with Bryozoans, Crustaceans, and Echinoids. These assemblages show a constant fauna cortege highlighted by the dominance of the amphi-Atlantic species Stramonita haemastoma. This species shows an increase in the number of specimens in the uppermost part of marine deposits, probably in relation with a climate warming in the MIS 5. This fauna of both intertidal rocky substrates and sandy substratum indicates environmental conditions close to the present-day Rabat-Témara coastline. As in other coastal locations of Africa from MIS 5, the Middle Stone Age Homo sapiens population benefitted from a littoral environment rich in coastal resources. Comparison between thanatocenoses and archaeological records allows us to identify both species available for Middle Stone Age population and those preferred for human use.  相似文献   
4.
5.
After many years of individual attempts to explore the underwater cultural heritage (UCH) of Egypt, the Supreme Council for Antiquities (SCA) established a department specializing in the field during the last decade of the twentieth century. The collaboration between this department and foreign missions led to the discoveries of a number of underwater sites and projects focusing on their protection, including mitigation work. This article presents the most important discoveries and displays the efforts of the SCA in the management of the UCH.  相似文献   
6.
Ferrari, M., El-Hedeny, M., Zakhera, M., El-Sabbagh, A. & Al Farraj, S., May 2018. Middle?Upper Jurassic marine gastropods from central Saudi Arabia. Alcheringa.

A total of 68 gastropod specimens are reported from the Middle?Upper Jurassic sedimentary successions exposed at central Saudi Arabia. The studied material comes from the Tuwaiq Mountain and Hanifa formations at the Khashm al Qaddiyah, Dirab, Jabal al Abakkayn and Maáshabah sections. Thirteen species are identified, described and illustrated. Among them, a new Aporrhais species (A. sauditica sp. nov.) is introduced. In addition, two further possible new Pseudomelania species from the same strata are mentioned. Other members of the assemblage include Kosmomphalus? sp. aff. K. reticulatus Fischer, Bourguetia? sp. aff. B. saemanni (Oppel), Bourguetia? sp., Ampullospira sp., Globularia? sp. cf. G. bajociana Fischer, Purpuroidea sp. aff. P. glabra Morris and Lycett, Purpuroidea sp., Cossmannea sp. aff. C. desvoidyi (d’Orbigny), Cryptoplocus sp. aff. C. depressus (Voltz) and Actaeonina? sp. Stratigraphically, seven species of this gastropod assemblage were only reported from the Middle Jurassic, whereas the other six ones are extending from the Middle to the Upper Jurassic of the studied succession. As compared with their gastropod content, the Khashm al Qaddiyah represents the richest section (33 out of 68 specimens, 48.5%), whereas the Maáshabah section showed an impoverished gastropod assemblage (only three specimens, 4.4%). The species reported here show paleobiogeographical affinities with coeval gastropod assemblages from India, east Africa, Middle East (Israel, the Sinai of Egypt) and western Tethys. The identified species confirm three depositional settings: open shelf lagoon, shoal/fore-shoal and open marine environments. The lower degree of fragmentation, poor sorting and scarcity of abrasion indicate a parautochthonous faunal assemblage.

Mariel Ferrari [] Instituto Patagónico de Geología y Paleontología (IPGP-CCT CONICET-CENPAT), Bvd. Brown 2915, U9120CD, Puerto Madryn?Chubut, Argentina; Magdy El-Hedeny* [] Department of Geology, Faculty of Science, Alexandria University, Alexandria 21568, Egypt; Mohamed Zakhera? [] Department of Geology, Faculty of Science, Aswan University, Aswan 81528, Egypt; Ahmed El-Sabbagh [] Department of Geology, Faculty of Science, Alexandria University, Alexandria 21568, Egypt; Saleh Al Farraj [] College of Science, King Saud University, Riyadh 12371, Saudi Arabia. *Also affiliated with Deanship of Scientific Research, King Saud University, Riyadh 11451, Saudi Arabia. ?Also affiliated with Vice Rectorate for Development and Quality, Najran University, Najran 11001, Saudi Arabia.  相似文献   
7.
8.
9.
The aim of this paper is to identify the frequency of congenital anomalies of the vertebral column in ancient Egyptians. The material for this study consisted of 272 skeletons excavated from Giza and belonging to the Old Kingdom (the time of the early pyramid builders). The vertebral columns of these skeletons were examined for the different types of congenital anomalies that affect the vertebrae. Nine cases (3.33%) were affected with spina bifida occulta, while six cases (2.22%) had transitional vertebrae at the lumbosacral joint. These frequencies are compared with other ancient populations. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号