全文获取类型
收费全文 | 249篇 |
免费 | 7篇 |
出版年
2023年 | 1篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 17篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 80篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 7篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有256条查询结果,搜索用时 15 毫秒
81.
Scholars agree that postreform House majority leadership strategies distinguish contemporary leaders from their predecessors. One such strategy is leaders' use of media to fulfill personal and member goals. Commonly presented evidence of this strategy is the increase in the number of times leaders appear in national evening newscasts. Yet most studies do not investigate the kind of media coverage leaders receive over time. Hence they do not show whether leaders have been successful in generating the sort of television attention consistent with the incentives that the literature identifies as driving them to adopt a media-oriented strategy. This article begins to address this gap in our understanding. Conducting a content analysis of network news accounts, we find that while postreform leaders have received more attention than their predecessors, coverage of them declined and leveled off in the 1990s. We also find that despite the drop in levels of attention accorded House majority-party leaders, they have maintained a plateau of higher news visibility relative to their primary competitors in the House, committee chairs, though there have been some recent exceptions to this trend that are highly suggestive. 相似文献
82.
Gary M. Pereira 《Geographical analysis》2002,34(1):21-33
A simple typology of relations between any two geographical scales is established by qualitatively comparing their respective grains and extents. This typology is applied to spatial, temporal, and spatiotemporal scales. It describes seven relations between any two scales in either space or time. These basic relations yield a set of 169 qualitatively different spatiotemporal scale relations, a subset of which is portrayed dia‐grammatically. If it is possible to transform processes or patterns from one scale in the relation to the other, up to four scaling methods may need to be simultaneously applied, depending on the relation. Scaling methods might be classified as forms of grain generalization, grain decomposition, extent extrapolation, or extent selection. This typology may also provide a framework for investigations of dependencies between scales, as well as a reference scheme for observations of scale nonstationarity. The possibility is offered that any relation that forms a nonintersecting hierarchy in either space or time is a relation between essentially independent scales. However, the use of this typology is contingent on a number of factors, and it is offered as a tool, rather than a solution, for problems of scale. 相似文献
83.
84.
85.
Distinctive age profiles result from certain types of mortality processes that affect modern African elephants. Large collections of fossil proboscidean bones sometimes have similar age profiles—for example, those of the Lehner and Dent assemblages are identical to age profiles seen in modern drought-caused die-offs. Two other samples of mammoths (one from the Fairbanks muck deposits and one from a site near Waco, Texas) have age profiles suggestive of a stable age distribution in a mature population, resulting in the first case from long-term attritional mortality, and in the other case from sudden “catastrophic” mortality. Other fossil proboscidean age profiles that show high proportions of prime-age adults may have resulted from prolonged or recurring die-offs. 相似文献
86.
Municipal solid waste management and planning traditionally have been regarded as the responsibility of local government. However, the legal climate surrounding solid waste management has become more constrained, placing local government at the mercy of the private waste management industry, and eroding the effectiveness of local waste planning efforts. This article provides an overview of recent court decisions impacting local government solid waste management. It also discusses current congressional activity relating to interstate waste transport and flow control, and assesses the potential effects of such legislation on public solid waste management and on privatization issues raised by critics of local control. 相似文献
87.
88.
89.
90.
Gary L. Gaile 《Geographical analysis》1979,11(3):273-288
Spread-backwash processes are central elements in regional development thought. This article argues that the main spread-backwash processes produce developmental change that has a general spatial form. Straightforward models of the processes of government incomes and expenditure flows, private capital flows, intraregional trade, migration-commuting, and the diffusion of innovations provide the rationale for the general distance decay form of developmental impact. Each model is supported by evidence from the relevant literature. It is argued that there is not a dichotomous set of spread versus backwash processes, but rather that the same set of processes yields differential spatial impacts. 相似文献