全文获取类型
收费全文 | 2390篇 |
免费 | 86篇 |
国内免费 | 68篇 |
专业分类
测绘学 | 130篇 |
大气科学 | 357篇 |
地球物理 | 83篇 |
地质学 | 355篇 |
海洋学 | 163篇 |
天文学 | 3篇 |
综合类 | 132篇 |
自然地理 | 1321篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 79篇 |
2021年 | 95篇 |
2020年 | 88篇 |
2019年 | 94篇 |
2018年 | 100篇 |
2017年 | 100篇 |
2016年 | 115篇 |
2015年 | 104篇 |
2014年 | 97篇 |
2013年 | 302篇 |
2012年 | 91篇 |
2011年 | 127篇 |
2010年 | 100篇 |
2009年 | 94篇 |
2008年 | 96篇 |
2007年 | 107篇 |
2006年 | 103篇 |
2005年 | 89篇 |
2004年 | 81篇 |
2003年 | 69篇 |
2002年 | 61篇 |
2001年 | 48篇 |
2000年 | 61篇 |
1999年 | 41篇 |
1998年 | 39篇 |
1997年 | 29篇 |
1996年 | 17篇 |
1995年 | 17篇 |
1994年 | 14篇 |
1993年 | 14篇 |
1992年 | 9篇 |
1991年 | 10篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有2544条查询结果,搜索用时 15 毫秒
91.
Ravi S. Prasad 《Climate Policy》2019,19(3):354-366
With poverty alleviation and sustainable development as key imperatives for a developing economy like India, what drives the resource-constrained state governments to prioritize actions that address climate change impacts? We examine this question and argue that without access to additional earmarked financial resources, climate action would get overshadowed by developmental priorities and effective mainstreaming might not be possible. A systematic literature review was carried out to draw insights from the current state of implementation of adaptation projects, programmes and schemes at the subnational levels, along with barriers to mainstreaming climate change adaptation. The findings from a literature review were supplemented with lessons emerging from the implementation of India’s National Adaptation Fund on Climate Change (NAFCC). The results of this study underscore the scheme’s relevance.Key policy insights
Experience with NAFCC implementation reveals that states require sustained ‘handholding’ in terms of financial, technical and capacity support until climate change issues are fully understood and embedded in the policy landscape.
Domestic sources of finance are critically important in the absence of predictable and adequate adaptation finance from international sources.
The dedicated window for climate finance fosters a spirit of competitive federalism among states and encourages enhanced climate action.
Enhanced budgetary allocation to NAFCC to strengthen the state-level adaptation response and create capacity to mainstream climate change concerns in state planning frames, is urgently needed.
92.
This paper considers how farmers perceive and respond to climate change policy risks, and suggests that understanding these risk responses is as important as understanding responses to biophysical climate change impacts. Based on a survey of 162 farmers in California, we test three hypotheses regarding climate policy risk: (1) that perceived climate change risks will have a direct impact on farmer's responses to climate policy risks, (2) that previous climate change experiences will influence farmer's climate change perceptions and climate policy risk responses, and (3) that past experiences with environmental policies will more strongly affect a farmer's climate change beliefs, risks, and climate policy risk responses. Using a structural equation model we find support for all three hypotheses and furthermore show that farmers’ negative past policy experiences do not make them less likely to respond to climate policy risks through participation in a government incentive program. We discuss how future research and climate policies can be structured to garner greater agricultural participation. This work highlights that understanding climate policy risk responses and other social, economic and policy perspectives is a vital component of understanding climate change beliefs, risks and behaviors and should be more thoroughly considered in future work. 相似文献
93.
E. O. Oladipo 《Natural Hazards》1993,8(3):235-261
Drought has been a recurring feature of the arid and semi-arid areas of Nigeria. This paper reviews the extent, severity, and consequences of drought and desertification in Nigeria with particular emphasis on the northern part of the country. The haphazard manner in which these environmental hazards have been tackled is examined and a systematic approach for the formulation of a national policy is proposed. It is recommended that a detailed formulation and implementation of the proposed policy plan is imperative to mitigate the often devastating impacts of drought and desertification in the very prone areas of Nigeria. Until such is done, some areas of Nigeria will always be vulnerable to the whims of an inevitable climatic hazard of drought and associated land degradation in the form of desertification. 相似文献
94.
本文从分析澳门80年代工业和本地生产总值不同变化趋势入手,指出澳门当前经济发展面临的主要问题是工业增长速度明显下降,进而分析其下降的原因,最后提出澳门产业结构调整及其远景发展目标。 相似文献
95.
本文以1973~1988年我国九省市国营工业为例,运用生产函数对不同省区国营工业的劳动力、资金技术进步等要素对产出的贡献进行比较分析. 相似文献
96.
This paper examines the link between poverty and land management within the context of New Zealand's almost total removal of subsidies to agriculture since 1984. The impact of these policy changes is explored through the findings from a detailed study of sixteen farms in the North Island hill country. Stress is identified as a primary link between social damage and environmental degradation. This link reinforces the impact of other linkages expressed in reduced production, lower stocking rates, and reduced capital inputs. Deregulation is claimed to be good. This paper shows that in certain circumstances this is not so. 相似文献
97.
中国地区工业结构变化与区际增长和分工 总被引:8,自引:1,他引:8
1979以来,中国地区工业结构发生了重要的变化。本文分析了这一变动的特征及其对区际增长和分工的作用,得出以下结论:(1)绝大多数省市区工业结构变化高于国家水平,但由于各地人均收入、区位性以及结构性差异,这种变动具有明显地理分异:南大北小,东西部大中部小。(2)各地工业结构变动普遍表现为重加工业地位上升,采掘工业地位下降,且多数省市区原材料工业和轻工业地位下降,高加工度化和重加工业化十分显著。(3)广东、江苏、福建、河北、安徽、湖南、陕西、浙江、甘肃、云南、四川等省区结构调整有利经济增长,其它省市区结构调整相对不利经济增长。(4)资源型地区数量减少,加工型地区较大幅度地增加,基本形成沿海沿江地区和陕西省以加工业为相对专业化部门,其它广大地区以采掘、原材料为相对专业化部门的区际分工格局。 相似文献
98.
杨解 《华东地质学院学报》1986,(1)
本文解决大水矿床排供结合问题是国民经济建设中具有实际意义的重要课题。本文较系统地论述了解决排供矛盾和排供结合的办法。着重从地质一水文地质条件,从矿山排水前后矿床地下水的补给、迳流、排泄条件来论证对排供结合方案的选择,并以一个典型的矿床作为实例加以阐明。 相似文献
99.
地勘经济改革的战略思想是建设适应社会主义市场经济的新体制,将现有的地勘队伍组建为"地质找矿的野战军"和"实行企业化的地方军".分别按事业机制和企业机制运行。如何实现地勘单位(地方军)的企业化,笔者认为首先必须用现代企业制度改造和重塑现有的多种经营企业,并分析了困难和有利条件,提出了相应的对策和措施,使多种经营企业真正成为符合现代企业制度要求的经济实体。加快发展部门产业经济,才能逐步推进地勘单位的企业化。 相似文献
100.
新时期农村产业结构优化调整研究 总被引:4,自引:0,他引:4
通过在农村长期的工作实践和对农村经济发展的考察,依据当前国内外发展对农村产业经济发展的要求,分析研究我国和河南省农村产业结构的发展现状和动态变化,提出农村产业结构调整的指导思想、原则及目标,据此,从农村产业结构调整、农业产业结构调整和种植业结构调整3个层次,研究提出农村产业结构调整的基本思路和方向,为有关部门决策农村经济发展提供科学依据. 相似文献