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   296篇
  免费   13篇
  2023年   1篇
  2021年   1篇
  2020年   7篇
  2019年   8篇
  2018年   7篇
  2017年   14篇
  2016年   19篇
  2015年   12篇
  2014年   8篇
  2013年   86篇
  2012年   10篇
  2011年   2篇
  2010年   9篇
  2009年   4篇
  2008年   7篇
  2007年   10篇
  2006年   2篇
  2005年   3篇
  2004年   1篇
  2003年   2篇
  2002年   5篇
  2000年   6篇
  1999年   6篇
  1998年   3篇
  1997年   4篇
  1996年   2篇
  1995年   2篇
  1994年   3篇
  1993年   3篇
  1992年   1篇
  1991年   7篇
  1990年   3篇
  1989年   4篇
  1988年   3篇
  1987年   2篇
  1986年   8篇
  1985年   1篇
  1984年   2篇
  1983年   4篇
  1982年   5篇
  1981年   3篇
  1980年   5篇
  1979年   1篇
  1978年   1篇
  1977年   6篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1969年   3篇
排序方式: 共有309条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Compared to the geographic wasteland south of your border, geography appears to have fared well in Canada, both as a formal discipline extending our understanding by illuminating the human and physical worlds, and as a subject taught at all levels to create informed and aware citizens. I known you think much remains to be done, and perhaps things always look a bit greener on the other side of the hill, but I hope you will not mind my somewhat envious gaze. In fact, when I received the five volumes of the 'curriculum guideline' for geography, issued by the Ontario Ministry of Education for the intermediate and senior divisions of your high schools (ome 1988), my feelings were not so much envy as panic, a panic that rapidly induced something close to intellectual paralysis. Because in a moment I can only describe now as utterly weak and foolish, I started to read them, only to learn that your senior students 'analyze, interpret … explain … design and develop networks, systems and simulations that involve six or more variables' (ome 1988, A12).
In retrospect, I still think my panic was justified. After 30 years of hard post-doctoral work I have reached the point where I can think about the interactions of maybe three variables, but hardly the combinatorial possibilities of six. Such ineptness would mean that I might just squeeze into your tenth grade and from there slowly work my way over the next two years towards those Olympian heights of analytical thought where dwell Ontario's high school graduates.  相似文献   
7.
This paper presents a model of United Kingdom local economic development characterised by a grassroots orientation and partnership between public and private actors—marriages à la mode. It then offers research findings on the emergence of Local Economic Initiatives (LEIs) from Western Australia and Tasmania. Factors in the structure of their respective political economies appear to have made for a speedier adoption in Western Australia than Tasmania of such alternative policy characteristics as a grassroots participatory approach to policy design and implementation, which is underwritten to a considerable extent by non earmarked public funds. Over and above the structural factors, an Australia‐wide network of LEI enthusiasts, within and outside government, has encouraged imitation of the Western Australian policy innovation in Tasmania. The marriages a la mode model has not been fully replicated in Australia, however, by virtue of the relatively low profile of business organisations in LEIs.  相似文献   
8.
9.
10.
This paper extends a compartmental epidemiological model for HIV transmission and AIDS incidence to include hierarchical and expansion spatial diffusion. An implication of the resultant model is that hierarchical diffusion causes the large infection growth rates of densely populated areas at the top of the central places hierarchy to “chain” down and dominate small local growth rates during the exponential-growth phase of the epidemic. Also, hierarchical diffusion causes a high transient growth rate in the first few years of a local epidemic. The spatial compartmental model fits observed AIDS incidence spatial diffusion patterns in Ohio reasonably well.  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