全文获取类型
收费全文 | 743篇 |
免费 | 36篇 |
国内免费 | 18篇 |
专业分类
测绘学 | 50篇 |
大气科学 | 132篇 |
地球物理 | 13篇 |
地质学 | 127篇 |
海洋学 | 110篇 |
综合类 | 26篇 |
自然地理 | 339篇 |
出版年
2024年 | 1篇 |
2023年 | 17篇 |
2022年 | 59篇 |
2021年 | 58篇 |
2020年 | 50篇 |
2019年 | 56篇 |
2018年 | 43篇 |
2017年 | 64篇 |
2016年 | 42篇 |
2015年 | 41篇 |
2014年 | 55篇 |
2013年 | 70篇 |
2012年 | 28篇 |
2011年 | 25篇 |
2010年 | 24篇 |
2009年 | 35篇 |
2008年 | 23篇 |
2007年 | 25篇 |
2006年 | 17篇 |
2005年 | 14篇 |
2004年 | 15篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有797条查询结果,搜索用时 15 毫秒
81.
82.
WANGHong GUChao-lin 《中国地理科学(英文版)》2002,12(2):152-156
Chinaˊs urban reforms have brought social progress and development,but a comprehensive national system of social welfare(for example,unemployment insurance,pensions,medical care and public housing)for new migrants from rural areas is lacking.One of the most remarkable changes in Chinese cities in the last decade was a change in so-cial“equality“,with the rise of new poverty both in individual communities and some social groups in urban society.Howev-er,there is little social assistance and public infrastructure for the migrants.Governments or communities or individual should pay attention to the control of new urban poverty and new slums.This paper consider that it is necessary to launch a successful policy,which include mainly:1)accommodating urban growth through low-cost investment projects;2)ur-ban economy depends heavily on successful macroeconomic policy;3)to broaden the three channels linking adjustment to the incidence of urban poverty;4)to restructure urban economic based on the high or new technology;5)to coordi-nate relationship between urban economic growth and environment management for sustainable development of Beijingˊs metropolitan fringe. 相似文献
84.
85.
Li DAR点云为小尺度地表形态的提取与表达提供了精确的数据源,但其高密度性与不确定性,导致应用Morse理论提取的特征点中含有大量的"伪特征点"。这里首先通过定义特征点指数等一系列概念,模拟特征点周围区域的地表形态,建立特征点重要性度量指标与计算方法;然后给出了地表重要特征点的提取算法;最后,进行了试验验证与分析。结果表明:提出的算法优于现有的持续值法与自然法则法,可以有效剔除"伪特征点",实现基于Li DAR点云小尺度复杂地形的特征点精确提取与多层次表达。 相似文献
86.
中国城镇住房分配从再分配体制向市场化为主的分配体制转变,深刻地影响政府、单位和市场在住房产权管理角色上的变化。利用广州市老八区的"五普"和"六普"数据,从住房产权结构变化、住房产权选择和住房产权空间形态等角度,分析政府、单位和市场在住房供应、分配和空间配置等住房产权管理中的角色变化。广州市2000年以来的住房产权结构变化反映了单位退出住房供应角色、政府保障房供应力度不够、市场成为最主要住房供应主体等特征。住房产权选择影响因素表明家庭与单位、政府之间的组织联系逐步弱化,与市场间的社会联系日益成为主导,家庭生命周期、家庭收入等体现家庭与市场间的市场联系变量成为城镇居民住房选择的最显著影响变量。住房产权空间形态重构表明,2000-2010年间,中心城区单位提供的体制内住房比重大幅度下降,并逐步被体制外住房所替代,政府提供的体制内住房则向郊区或近郊区形成集聚,导致体制内外住房空间布局出现一定"倒置",住房来源过度市场化、住房供应主体变化和级差地租等因素是其重要形成原因。研究还显示,单位不再承担住房供应任务后,尽管政府在住房调控上起到重要作用,但未充分承担起住房供应任务,城镇居民住房来源"过度市场化"趋势。为此,政府应加大保障房建设力度,并在区位上力求分散、均衡和避免郊区化,以避免加重保障房社区居民居住空间和社会空间上的双重边缘化。随着城市住房市场化的深入发展,中国城市大规模的房地产开发和政府房地产调控政策的制订过程中,更应关注快速全球化、现代化和市场化背景下居民家庭结构、社会经济地位等体现家庭与市场间的社会联系的变量对居民住房选择偏好的影响。 相似文献
87.
《Geoforum》2015
North Americans have had a profound affect on wildlife, especially migratory animals such as elk, bison, salmon, and many species of birds. Migration is a vital adaptation for these and other species. Yet despite this importance and the myriad ways in which people have influenced and understood migration, environmental geographers have devoted scant attention to it. This paper examines the role of animal migration in North American history. North Americans have affected and managed animal migrants in six primary ways: transforming migrant habitats; harvesting migrants; obstructing and facilitating migrants; working across borders; visualizing migrants; and accepting and resisting migrants. I examine these different aspects of animal migration history in North America and end with a discussion of how other geographers such as environmental historical geographers, political ecologists, and animal geographers can employ this framework. 相似文献
88.
《Geoforum》2015
Over the last decade, fire governance practices in the British Fire and Rescue Service (FRS) have undergone fundamental transformation. Rather than just being responded to as and when they occur, the FRS have adopted a range of anticipatory governing strategies to govern fires in anticipation of their occurence. This turn towards anticipatory governance has been facilitated in no small part by the digital infrastructure now embedded in the FRS. Composed of data, hardware, software, fibre-optic cables along with human analysts and organisational processes, this infrastructure operates to make risk projections on fire which shape and condition strategic decision making. This paper explores the operation of this digital infrastructure through the notion of interface. Drawing on empirical material relating to processes of data sourcing and risk calculation, interfaces account for the sites, moments and experiences in which human and non-human agents relate to one another in making fire risk projections. Showing relations to exist spatially, temporally and sensually, I argue that interfaces are crucial to the operation of an anticipatory security apparatus which relies on digital devices. 相似文献
89.
《Geoforum》2015
This article examines changing water governance modalities in the context of the neoliberalization of nature. Specifically, it focuses on Brazilian water sector reforms passed in 1997 that mandate decentralized and participatory decision-making at the river basin scale. Critics have suggested that rescaling, decentralization, and participatory governance mechanisms – supposedly intended to render decision-making more equitable, accessible, and relevant – can serve to legitimate, facilitate, and thus further embed processes of neoliberalization. Examining the impact of Brazil’s water sector reforms on the state–society relationship, this article presents a case study of water governance in the São Francisco River Basin and finds that the reforms – despite their neoliberalizing potential – have not significantly contributed to the neoliberalization of governance therein. Instead, water governance continues to be characterized by longstanding patterns of traditional elite control. Through an institutional and socio-natural analysis, this article describes and accounts for the continued dominance of these patterns relative to neoliberalization and explores activists’ efforts to use water sector reforms to pursue more progressive possibilities. The article concludes with a discussion of the implications for variegation and contestation in ongoing debates over neoliberal natures. 相似文献
90.
《Geoforum》2015
This paper investigates the spaces for participation that have been created by readiness preparations launched in connection with the international initiative “Reduced Emissions from Deforestation and Forest Degradation” (REDD+) in Colombia and Costa Rica. I analyse the emergence of these spaces and who is leading the process in each country. My findings indicate that in Costa Rica, the public sector is leading preparation activities and creating the public spaces for participation in REDD to which private actors are invited. In Colombia on the other hand, NGOs, development assistance agencies and other private actors are leading the process and the state is the invited actor. I identify four factors that determine the scope of different actors’ possibilities to participate in the REDD+ spaces. These are (a) control of key resources, (b) ideological affinity, (c) the creation and dissemination of information and knowledge, and (d) the creation of norms to validate REDD+ pilot initiatives. The separation between these factors is not clear-cut and consequently they reinforce each other at different levels. The research presented here contributes to a better understanding of the implications that national REDD+ politics may have in the future functioning of the programme. 相似文献