全文获取类型
收费全文 | 499篇 |
免费 | 26篇 |
国内免费 | 12篇 |
专业分类
测绘学 | 38篇 |
大气科学 | 102篇 |
地球物理 | 98篇 |
地质学 | 95篇 |
海洋学 | 141篇 |
天文学 | 2篇 |
综合类 | 12篇 |
自然地理 | 49篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 11篇 |
2021年 | 12篇 |
2020年 | 13篇 |
2019年 | 10篇 |
2018年 | 6篇 |
2017年 | 40篇 |
2016年 | 23篇 |
2015年 | 20篇 |
2014年 | 59篇 |
2013年 | 46篇 |
2012年 | 29篇 |
2011年 | 38篇 |
2010年 | 37篇 |
2009年 | 24篇 |
2008年 | 29篇 |
2007年 | 24篇 |
2006年 | 24篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 16篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有537条查询结果,搜索用时 15 毫秒
1.
Historical space as narrative medium: on the configuration of spatial narratives of time at historical sites 总被引:1,自引:0,他引:1
This paper examines how narratives of history are organized spatially at historical sites and memorial spaces, especially
in urban settings and in places invested with a sense of collective memory. Much recent research has focused on landscape,
memory, and place and how relationships of political and social power influence the representation of historical events in
public spaces. Although the meaning of such sites may be hotly contested for long periods of time, we focus here on narrative
theory and the related, but unexplored, issue of how such historical stories are configured on the ground at actual historical
sites. We identify a number of narrative strategies which are frequently used to configure historical stories in space. Declamatory
strategies using markers presenting a snapshot of an event are common, but sequential and non-sequential linear strategies
are also used, as are thematic strategies that cross-cut space and time to present complex historical stories at various spatial
scales. Examples are drawn from a range of historical sites in North America, Europe and Israel. 相似文献
2.
The EU Green Paper on Maritime Policy is the European response to the new generation of ocean strategies based on science, technology and innovation aimed at new objectives, such as the strengthening of security and access to new resources. The European character of the proposal is found in the presence of social, cultural and historical elements, what is called the “European vision”. The viability of a European vision of the oceans and the idea of maritime empire as an extension of the current concept of empire within the general context of emerging ocean strategies are the elements offered up for debate on this European Union initiative. 相似文献
3.
The North Pacific has the world's largest groundfish fisheries, with a value in excess of $1 billion annually. The North Pacific also is home to the largest population of Steller sea lions (SSL), an ancient species that is now endangered. Decline of the western stock of SSL in the 1970–1990s coincided with the US nationalization and exponential growth in the Gulf of Alaska and Bering Sea/Aleutian Islands groundfish fishery.The article treats five aspects of the competition between the fishery and protection of the endangered species. First, we analyze competition of interests in the use, management, and preservation of the North Pacific commons, including offshore and near-shore fisheries, environmental organizations, governments (federal, state, and local), and the scientific community. Second, the article compares and contrasts provisions of the National Environmental Policy Act, the Marine Mammal Protection Act, the Endangered Species Act, and the Magnuson–Stevens Act (as amended in 1996 by the Sustainable Fisheries Act).Third, we examine the regulatory environment with a focus on the National Marine Fisheries Service (NMFS) and its relationship to the North Pacific Fishery Management Council. We illustrate how NMFS establishes fishery management plans and the methods, such as crafting biological opinions and environmental-impact-statements, it uses to resolve conflicts. Fourth, we investigate how the dual pressures on the agency—to increase fisheries production for the benefit of the industry and to preserve endangered marine species—have affected its culture (behavioral norms and operational codes). Then, the article explains agency changes in terms of crises, competition among affected interests, and development of new scientific knowledge.The article concludes by drawing lessons from the SSL controversy in the North Pacific which may pertain to national and global biodiversity conflicts. These concern the role of law in biodiversity protection, the role of science, and agency capacity for change. 相似文献
4.
This research examines attempts to develop co-management arrangements in the Maine lobster and Chesapeake Bay blue crab fisheries. It finds that the attributes of user groups and resources as well as government support are important in facilitating the development of co-management, but are not sufficient. This study highlights that the process of developing institutions for co-management is lengthy and time consuming and that user groups do not necessarily embrace changes to the status quo. I argue that the nature of distributional conflict and the affiliation of policy entrepreneurs account for variation in the development of co-management regimes in these cases. 相似文献
5.
In 1998, the Australian Government released Australia's Oceans Policy (AOP), a world first policy initiative focused on providing a framework for integrated ecosystem-based management of Australia's vast marine domain. The South East Regional Marine Plan, the first regional marine plan to be implemented under AOP, was released on 21 May 2004. This paper argues that although full integration across sectors and jurisdictions has not occurred, new AOP initiatives, institutions and governance processes have considerably increased sectoral and jurisdictional coordination in the South East region. 相似文献
6.
试论我国城市发展方针 总被引:6,自引:0,他引:6
在执行重重工业的发展战略和城乡分割体制的计划经济背景下,我国制定了“控制大城市规模,合理发展中等城市,积极发展小城市”的城市建设方针。但是分析表明,这一方针不能适应市场经济和对外开放形势的需要,也不符合我国人多地少、农村剩余劳动力多的国情,必须调整现有的城市发展方针,选择适宜的城市化发展道路。因此,本文就适度发展大中城市,提高城市现代化水平;加速乡村城市化,积极合理发展小城镇;以及根据不同地区的具体情况,因地制宜地指定城市化途径等方面作了探讨。 相似文献
7.
Despite the increasing public profile of same-sex issues, health policies are often shaped by heteronormative assumptions.
The health concerns of lesbian, gay, bisexual, transsexual/transgender, two-spirit, intersex, queer and questioning (LGBTTTIQQ)
people are complex and require broadening from an often exclusively sexual health and risk focus to a more holistic approach.
In this context, this paper illustrates how a critical feminist geography of health, with its focus on the mutual construction
of gender relations, space and place, potentially enhances and extends current understandings of public health policy and
practice. Moreover, the use of a policy lens foregrounding gender and other power relations suggests that feminist research
and coalitions facilitate participatory processes that address “the politics of discourse.” In particular, public health nursing
practice can enhance the construction of spaces of resistance that challenge heteronormative discourse through research strategies
focused on sexual minority communities’ health experiences and their visions for supportive care. In this respect, two strategies
consistent with public health priorities to increase knowledge and participate in alliances are described. Ethnographic research
with childbearing lesbians demonstrates that attention to institutional dynamics that foster safe spaces can facilitate access
to public health services. Public health nurses’ involvement in community coalitions can enhance dissemination of community
knowledges. The implications for gender inclusive and place-sensitive public health nursing practice include the development
of sensitive educators, meaningful educational curriculum and related program planning, explicit policies, community partnerships
and political leadership in institutional and research venues. 相似文献
8.
Christine S McCulloch 《Area》2006,38(1):24-33
Public participation in transparent decisionmaking has been proposed as a panacea for environmental protection. Bargaining theory suggests drawbacks to transparency such as hardening of attitudes and intransigence. Yet achievement of consensus on environmental values for integrated water resource management demands public involvement. Historical study of attempts to prevent reservoir construction in upland valleys designated for protection of nature suggests that 'closed-door' bargaining proved more effective for environmentalists than open, public debate. Records now open for analysis of disputes over Teesdale and Farndale, 1950–1970, allow comparisons to be made between behind-the-scenes deliberations and 'open-door' public discussion. The ambition of progressing from public participation to devolution of environmental decisionmaking and responsibility to the local scale demands more conceptualization of the process of decisionmaking on water resource development. 相似文献
9.
中国西部退耕还林(草)和沙漠化土地绿化的区域性气候效应 总被引:10,自引:0,他引:10
中国正在实施的西部大开发必将导致较大规模的土地利用和地表覆盖(LULC)变化,其中最重要的两类LULC变化是退耕还林(草)和沙漠化土地绿化工程。利用最新的全球地表特征资料数据库(GLCCD)识别以上两项生态建设工程的实施规模与范围,并以此更新了目前比较流行的区域气候模式的下边界条件,利用修正了的区域气候模式研究上述大规模LULC变化可能对中国区域性气候造成的影响。使用的卫星资源数据库是由美国地质测绘局(USGS)和Nebraska-Lincoln大学牵头,根据NOAA卫星的AVHRR资料、USGS掌握的高分辨率数字化地图,以及生态区划和植被分布等资料组建的。 相似文献
10.