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   186篇
  免费   13篇
  2018年   1篇
  2017年   1篇
  2016年   4篇
  2015年   7篇
  2014年   2篇
  2013年   9篇
  2012年   15篇
  2011年   15篇
  2010年   14篇
  2009年   18篇
  2008年   13篇
  2007年   11篇
  2006年   8篇
  2005年   8篇
  2004年   4篇
  2003年   1篇
  2002年   2篇
  2001年   2篇
  2000年   1篇
  1999年   1篇
  1998年   3篇
  1996年   6篇
  1995年   2篇
  1994年   3篇
  1993年   5篇
  1992年   4篇
  1991年   2篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1983年   3篇
  1982年   1篇
  1981年   4篇
  1979年   1篇
  1978年   2篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1967年   1篇
  1965年   1篇
  1963年   1篇
  1955年   1篇
排序方式: 共有199条查询结果,搜索用时 15 毫秒
1.
2.
This article reports a generalised and systematic approach to the thermoluminescence (TL) dating of samples which suffer from anomalous fading. We hypothesise that the TL signal from each mineral phase is composed of a stable and an unstable portion. The decay of the unstable TL is accelerated thermally, until only stable TL remains. The dating is then carried out on this stable signal. The results, on four known-age, coeval samples, exhibiting gross anomalous fading (25-50% loss over a few days), indicate that many, if not all, samples may successfully be dated with this approach.  相似文献   
3.
Digital analysis of Landsat data is applied to up-dating land cover maps for the Goondiwindi district of southern, inland Queensland. The imagery was paired with climax cover maps obtained from land systems reports with analysis conducted separately for each of three climax cover types (open forest, woodland and open woodland). Computer classification using this approach produced readily interpreted and reliable results. This work demonstrates that Landsat can be used in conjunction with existing, land systems derived maps to produce data that combine the advantages of two approaches to environmental survey, the former being based on current land cover/land use and the latter on the original environment and its land use potential.  相似文献   
4.
5.
ANDREW HEROD† 《对极》1991,23(4):385-402
This paper analyzes the responses to two separate closures of a large glass manufacturing plant in Clarksburg, West Virginia, to examine how geography has been integral to the conduct of local political practice in this community. When the plant, by far the local area's largest manufacturing employer, first closed in 1979 the state and local government put together a considerable package of incentives to attract a purchaser for the facility. However, although glass production continued, the plant was again closed in 1987 after a corporate takeover. In response to this second closure the characteristically pro-business Governor of West Virginia initiated an almost $650 million lawsuit against the plant's new owners. The plant's union leaders on the other hand collaborated with city government officials and local business interests to constrain community opposition to the closure. The paper argues that this paradoxical situation, of actors taking up positions contrary to those which an ageographical class analysis would have predicted, was the result precisely of their locality dependence in the face of mobile capital.  相似文献   
6.
Economic geography has undergone a number of paradigm shifts since the Von Thunen model was at the peak of its popularity in the 1960s and 1970s. This study examines the cost of moving wheat from farm to ship in South Australia and constructs a transport-cost surface for the season 1991/92. Transport costs still exert a very important influence on farm returns and land values. Governments and other authorities, when making decisions in the name of rationalisation, or microeconomic reform, should examine very carefully the spatial consequences of their actions. In the short-run at least, the farmer's world is very much a normative and partial equilibrium one. At least in respect of a significant Australian agricultural enterprise, normative and partial equilibrium models should not be seen as obsolete.  相似文献   
7.
8.
Mining of mineral sands has taken place on North Stradbroke Island for over 40 years. Revegetation of mined areas creates a mosaic of seral classes. For a mine site in the northwest of the island, Landsat Thematic Mapper data were used successfully to map the distribution of seven seral classes resulting from mining rehabilitation. Faecal pellet counts were used to assess usage of these areas and surrounding natural forest by swamp wallabies, Wallabia bicolor. Results indicated that revegetated sites from 2 to 4 years in age were heavily used by wallabies. Older revegetated sites, dominated by senile Acacia cunninghamii, and offering little or no forage, were avoided. Swamp wallabies used revegetated sites for night-time feeding sessions and rested, during the day, in surrounding eucalypt forest.  相似文献   
9.
10.
The article investigates homemaking processes of mature age gay men living in a provincial Australian town. All too often the experience of older gay men living in non-metropolitan centres has slipped the attention of scholars. The article draws on interview data collected in Townsville (Queensland, Australia) from ten men over 40 years of age who self-identified as gay. These men were asked to explain why they live in Townsville, their understanding of home, and if they understand Townsville as home. We investigate the spatialised understandings of home articulated by these gay men, focusing on two mutually constituted geographical scales: Townsville-as-home and house-as-home, including the material objects within domestic space. For older gay men to call a provincial town home is an ongoing, complex process of reconciling multiple and contradictory subjectivities across different geographical scales. How older gay men constitute Townsville-as-home provides important insights about both non-heterosexual life in provincial centres and how to conceptualise home—as a paradoxical space, contested site, and as multiscalar.  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