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   448篇
  免费   21篇
  2023年   6篇
  2020年   9篇
  2019年   17篇
  2018年   25篇
  2017年   24篇
  2016年   23篇
  2015年   10篇
  2014年   19篇
  2013年   113篇
  2012年   12篇
  2011年   18篇
  2010年   16篇
  2009年   16篇
  2008年   19篇
  2007年   13篇
  2006年   5篇
  2005年   9篇
  2004年   9篇
  2003年   3篇
  2002年   4篇
  2001年   5篇
  2000年   6篇
  1999年   3篇
  1998年   4篇
  1997年   8篇
  1996年   6篇
  1995年   5篇
  1993年   4篇
  1992年   5篇
  1991年   2篇
  1990年   3篇
  1989年   4篇
  1988年   4篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1981年   2篇
  1980年   7篇
  1978年   4篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1965年   1篇
  1962年   1篇
  1948年   2篇
排序方式: 共有469条查询结果,搜索用时 31 毫秒
11.
12.
13.
Madagascar's culture is a unique fusion of elements drawn from the western, northern, and eastern shores of the Indian Ocean, and its past has fascinated many scholars, yet systematic archaeological research is relatively recent on the island. The oldest traces of visitors are from the first century AD. Coastal settlements, with clear evidence of ties to the western Indian Ocean trading network, were established in several places over the next millennium. Important environmental changes of both plant and animal communities are documented over this period, including the extinctions of almost all large animal species. Urban life in Madagascar began with the establishment of the entrepôt of Mahilaka on the northwest coast of the island in the twelfth century. At about the same time, communities with ties to the trade network were established around the island's coasts. From the fourteenth to the sixteenth century, social hierarchies developed in several regions of the island. During the succeeding two centuries, Madagascar saw the development of state polities.  相似文献   
14.
15.
16.
17.
18.
Policy advocacy is an increasingly important function for many nonprofit organizations, yet their advocacy activities have largely escaped theoretical grounding. The literature on nonprofits has described how they engage in policy advocacy, without linking them to theories of policy change. The policy studies literature, on the other hand, has explained how various forms of influence result in policy change, but has largely ignored organizational perspectives on those processes. These two literatures remain largely disconnected. Drawing upon interviews with a purposive sample of policy advocacy directors at 31 nonprofit organizations, this study applies Q‐methodology to identify and describe six distinct policy advocacy strategies employed by the organizations, and their resonant theoretical views of policy processes. These findings suggest strategic approaches for nonprofits seeking to influence policy processes. They also enhance the academic literature on policy processes by adding the advocates’ views and expectations. Implications for further research are also identified.  相似文献   
19.
20.
Plusquellec, Y. &; Wright, A.J., October 2017. Revision of the Early Devonian tabulate coral Pleurodictyum bifidum from New South Wales. Alcheringa 41, xxx–xxx. ISSN 0311-5518.

The tabulate coral Pleurodictyum bifidum Jones, 1944 Jones, O.A., 1944. Tabulata and Heliolitida from the Wellington district, N.S.W. Journal and Proceedings of the Royal Society of New South Wales 77, 3339. [Google Scholar], from the Early Devonian (Pragian or lower Emsian) Garra Formation of central New South Wales, Australia is revised on the basis of the holotype and three other specimens. It is selected as the type species of the new monotypic genus Bifidomeria (Family Roemeriidae), which differs from Roemeria in its strictly cerioid corallum, its bifid septal spines and aspects of its microstructure. Study of the detailed microstructure of two other tabulate corals from the Devonian of New South Wales has led to the following revised generic assignments: Michelinia progenitor Chapman, 1921 Chapman, F., 1921. New or little known fossils in the National Museum. Part XXV—some Silurian tabulate corals. Proceedings of the Royal Society of Victoria 33, 212225. [Google Scholar], previously assigned to Roemeripora, is assigned to Roemeria, and Holacanthopora clarkei Wright &; Flory, 1980 Wright, A.J. &; Flory, R.A., 1980. A new Early Devonian tabulate coral from the Mount Frome Limestone, near Mudgee, New South Wales. Proceedings of the Linnean Society of New South Wales 104, 211219. [Google Scholar] is assigned to Michelinia.

Yves Plusquellec [], Université de Bretagne Occidentale, CNRS-UMR 6538 ‘Domaines océaniques’, Laboratoire de Paléontologie, UFR Sciences et Techniques, 6 avenue Le Gorgeu, CS 98837, F-29283 Brest, France; Anthony Wright [], GeoQuEST Research Centre, School of Earth &; Environmental Sciences, University of Wollongong, Wollongong NSW 2522, Australia.  相似文献   
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