全文获取类型
收费全文 | 1261篇 |
免费 | 83篇 |
国内免费 | 38篇 |
专业分类
测绘学 | 34篇 |
大气科学 | 54篇 |
地球物理 | 11篇 |
地质学 | 255篇 |
海洋学 | 115篇 |
综合类 | 128篇 |
自然地理 | 785篇 |
出版年
2024年 | 5篇 |
2023年 | 19篇 |
2022年 | 33篇 |
2021年 | 55篇 |
2020年 | 33篇 |
2019年 | 27篇 |
2018年 | 43篇 |
2017年 | 52篇 |
2016年 | 48篇 |
2015年 | 34篇 |
2014年 | 49篇 |
2013年 | 56篇 |
2012年 | 49篇 |
2011年 | 63篇 |
2010年 | 49篇 |
2009年 | 50篇 |
2008年 | 47篇 |
2007年 | 73篇 |
2006年 | 71篇 |
2005年 | 62篇 |
2004年 | 51篇 |
2003年 | 49篇 |
2002年 | 50篇 |
2001年 | 70篇 |
2000年 | 63篇 |
1999年 | 49篇 |
1998年 | 42篇 |
1997年 | 19篇 |
1996年 | 7篇 |
1995年 | 10篇 |
1994年 | 15篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有1382条查询结果,搜索用时 15 毫秒
1.
衡阳市生态环境现状及其改善对策 总被引:1,自引:5,他引:1
陈国生 《云南地理环境研究》2003,15(3):71-76
资源的不合理开发利用导致衡阳生态环境严重恶化。加强生态环境保护与建设对衡阳乃至湖南的可持续发展具有重要的意义。在分析衡阳市资源开发存在问题及其主要原因的基础上j探讨了在资源开发中建立可持续发展的良性生态环境的途径和措施,指出了要发展生态产业、开展生态环境的保护和建设,必须大力实施生态农业、生态林业、生态能源、生态旅游等生态经济工程,从而为衡阳市经济建设莫定坚实的生态可持续发展基础。 相似文献
2.
资金结构的不合理使一些地勘单位的发展步履维艰。增加财务杠杆利益,优化资本结构,保持良好的财务状况,发挥资金的有效利用率,才能实现资金的最大利润率,使地勘单位适应市场经济环境,提高其经济实力。 相似文献
3.
Urban land transformation for pro-poor economies 总被引:1,自引:0,他引:1
Solomon Benjamin 《Geoforum》2004,35(2):177-187
The transformation of land into a setting for clustering local economies can become an important cornerstone of poverty policy. This transformation has several functional aspects, which in turn have important institutional and political aspects. Underlying both the functional and institutional factors is the role of local government and local democracy. Such a conceptualization puts to center stage several paradoxes: A terrain that seems “slum-like” turns out to be highly productive and employment generating. Complex tenure forms and mixed land use seen as “unplanned” turn out to be pre-requisites for economic development. There are institutional paradoxes that contrast efforts at “transparency” and managerial “best practices”. Here, the messiness of local bureaucracies in municipal government turns out to be critical for poor groups to influence interventions in their favor. Influencing the public process may be more effective in stealth-like ways rather taking a more visible approach. Most fundamentally these issues remind us that the potential of cities to reinforce or reduce poverty moved far beyond projects and programs and the normative frameworks used by planners and administrators. Instead, it is the transformative process of turning land into economic settings that might be at the center stage. This is a stage where poor groups are the central actors who stealth-like draw on complex alliances across ethnic and class lines to shapes cities in their interests. 相似文献
4.
5.
6.
7.
M. Anne Visser Nik Theodore Edwin J. Melendez Abel Valenzuela Jr. 《Urban geography》2017,38(2):243-265
Day labor worker centers have emerged as an important mode of regulatory action in the informal economy of major US cities. Research suggests that these organizations are beneficial in improving employment outcomes experienced by migrant workers engaged in this labor market sector. Yet, the extent to which these organizations impact the social integration of this working population remains relatively undeveloped in the literature. Using data from the National Day Labor Survey, we examine the impact of day labor worker centers on the level of social inclusion experienced by migrant day laborers. We find that worker centers have a modest, but statistically significant, impact on the levels of social integration experienced by this working population and that this varies from city to city. Ultimately we argue that the social intermediary role of these organizations may offer a type of counter mobilization necessary to promote the socioeconomic integration of this working population, but that issues of capacity remain. 相似文献
8.
生态经济战略是江西21世纪发展的必然抉择 总被引:1,自引:8,他引:1
根据生态经济战略的核心问题和江西省的实际情况,分析了江西实施生态经济战略的必要性与可行性,指出了江西开展生态经济建设的几个切入点。 相似文献
9.
《Geoforum》2016
Working through a Caribbean case study, this paper examines the networks and associations of Fair Trade bananas as they move both materially and morally from farms in St Vincent and the Grenadines to supermarkets and households in the United Kingdom. In doing so, the paper provides grounded empirical evidence of Fair Trade’s moral economy as experienced by banana producers in the Caribbean. The paper follows Nancy Fraser’s distinction between ways of framing justice to argue that, in order to transcend its complex postcolonial positionalities, the Fair Trade Foundation needs to include recognition in its moral economy as well as representation and redistribution. The paper compares the moral framework of Fair Trade as an ideology and social movement with the lived experience of certified Fairtrade banana farmers in the Windward Islands who work mostly for, rather than within, an idealized moral economy. The paper also contributes to several recent debates in the agri-food literature exploring the interconnections between production and consumption, the role of materiality in contemporary food networks, the historical and (post)colonial nature of food moralities, and links between political and moral economies of food. Following an outline of recent debates about the moral economies of food and its relation to Fair Trade as a movement, the paper dissects the moral economy of the Fairtrade Foundation, highlighting the historical and geographical, material and symbolic, gendered and generational ways that food producers in the Global South (in this case, banana farmers in St Vincent and the Grenadines) may be counterposed to ‘responsible’ consumers in the Global North. Despite the good intentions of those who promote the Fair Trade movement through the Fairtrade Foundation and the Fairtrade Labelling Organisation (FLO), our case study reveals a moral economy of non- (or partial) recognition, which has a range of unintended consequences and paradoxical effects. 相似文献
10.
Since it was first proposed in 2000, the concept of the Anthropocene has evolved in breadth and diversely. The concept encapsulates the new and unprecedented planetary-scale changes resulting from societal transformations and has brought to the fore the social drivers of global change. The concept has revealed tensions between generalized interpretations of humanity’s contribution to global change, and interpretations that are historically, politically and culturally situated. It motivates deep ethical questions about the politics and economics of global change, including diverse interpretations of past causes and future possibilities. As such, more than other concepts, the Anthropocene concept has brought front-and-center epistemological divides between and within the natural and social sciences, and the humanities. It has also brought new opportunities for collaboration. Here we explore the potential and challenges of the concept to encourage integrative understandings of global change and sustainability. Based on bibliometric analysis and literature review, we discuss the now wide acceptance of the term, its interpretive flexibility, the emerging narratives as well as the debates the concept has inspired. We argue that without truly collaborative and integrative research, many of the critical exchanges around the concept are likely to perpetuate fragmented research agendas and to reinforce disciplinary boundaries. This means appreciating the strengths and limitations of different knowledge domains, approaches and perspectives, with the concept of the Anthropocene serving as a bridge, which we encourage researchers and others to cross. This calls for institutional arrangements that facilitate collaborative research, training, and action, yet also depends on more robust and sustained funding for such activities. To illustrate, we briefly discuss three overarching global change problems where novel types of collaborative research could make a difference: (1) Emergent properties of socioecological systems; (2) Urbanization and resource nexus; and (3) Systemic risks and tipping points. Creative tensions around the Anthropocene concept can help the research community to move toward new conceptual syntheses and integrative action-oriented approaches that are needed to producing useful knowledge commensurable with the challenges of global change and sustainability. 相似文献