全文获取类型
收费全文 | 689篇 |
免费 | 26篇 |
国内免费 | 9篇 |
专业分类
测绘学 | 15篇 |
大气科学 | 49篇 |
地球物理 | 155篇 |
地质学 | 237篇 |
海洋学 | 48篇 |
天文学 | 147篇 |
综合类 | 2篇 |
自然地理 | 71篇 |
出版年
2023年 | 3篇 |
2021年 | 15篇 |
2020年 | 14篇 |
2019年 | 17篇 |
2018年 | 22篇 |
2017年 | 10篇 |
2016年 | 28篇 |
2015年 | 16篇 |
2014年 | 18篇 |
2013年 | 38篇 |
2012年 | 27篇 |
2011年 | 29篇 |
2010年 | 28篇 |
2009年 | 38篇 |
2008年 | 31篇 |
2007年 | 19篇 |
2006年 | 26篇 |
2005年 | 23篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 25篇 |
2001年 | 13篇 |
2000年 | 23篇 |
1999年 | 12篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 13篇 |
1995年 | 17篇 |
1994年 | 11篇 |
1993年 | 17篇 |
1992年 | 15篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1970年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有724条查询结果,搜索用时 468 毫秒
101.
102.
Julien Léger Raphaël Pik Bouchaïb Tibari Sébastien Ternois Mary Ford Chantal Peiffert Julien Mercadier 《Geostandards and Geoanalytical Research》2023,47(2):219-242
The in situ (U-Th-Sm)/He and U/Pb laser-ablation double-dating procedure is a valuable method that can provide a large dataset relatively efficiently in contrast with conventional bulk helium thermochronometry. In this study, we evaluate the potential age error associated with the double ablation procedure and report the in situ (U-Th-Sm)/He double-ablation dating of 249 zircons from the Fish Canyon Tuff locality. With LA-ICP-MS pseudo-depth profiling and 3D numerical modelling, we show that the concentric double-ablation procedure in minerals with U-Th-Sm zoning can generate a significant (U-Th-Sm)/He age error (positive or negative), resulting in over-scattering and/or an offset of the mean age. Pseudo-depth profiling is insufficient to predict the individual age error, partly because of the superimposed ablations. To evaluate the consequence of this inherent bias, we confront a synthetic age distribution to the error expected for U-Th-Sm zoned zircons analysed with double-ablation (U-Th-Sm)/He thermochronometry. As expected, a strong age bias causes the spreading of peak ages, downgrading the original signal. Yet, the throughput of the ablation-based method can allow intra- and inter-sample peak age identification and comparison, and the coupling of (U-Th-Sm)/He and U/Pb ages extends our ability to deconvolute a multimodal age spectrum. 相似文献
103.
Climate change and mental health: an exploratory case study from Rigolet, Nunatsiavut, Canada 总被引:1,自引:0,他引:1
Ashlee Cunsolo Willox Sherilee L. Harper James D. Ford Victoria L. Edge Karen Landman Karen Houle Sarah Blake Charlotte Wolfrey 《Climatic change》2013,121(2):255-270
As the impacts from anthropogenic climate change are increasing globally, people are experiencing dramatic shifts in weather, temperature, wildlife and vegetation patterns, and water and food quality and availability. These changes impact human health and well-being, and resultantly, climate change has been identified as the biggest global health threat of the 21st Century. Recently, research is beginning to indicate that changes in climate, and the subsequent disruption to the social, economic, and environmental determinants of health, may cause increased incidences and prevalence of mental health issues, emotional responses, and large-scale sociopsychological changes. Through a multi-year, community-led, exploratory case study conducted in Rigolet, Nunatsiavut, Labrador, Canada, this research qualitatively explores the impacts of climate change on mental health and well-being in an Inuit context. Drawing from 67 in-depth interviews conducted between January 2010 and October 2010 with community members and local and regional health professionals, participants reported that changes in weather, snow and ice stability and extent, and wildlife and vegetation patterns attributed to climate change were negatively impacting mental health and well-being due to disruptions in land-based activities and a loss of place-based solace and cultural identity. Participants reported that changes in climate and environment increased family stress, enhanced the possibility of increased drug and alcohol usage, amplified previous traumas and mental health stressors, and were implicated in increased potential for suicide ideation. While a preliminary case study, these exploratory findings indicate that climate change is becoming an additional mental health stressor for resource-dependent communities and provide a baseline for further research. 相似文献
104.
105.
106.
D. L. Band L. A. Ford J. L. Matteson D. M. Palmer B. J. Teegarden M. S. Briggs G. N. Pendleton R. D. Preece W. S. Paciesas 《Astrophysics and Space Science》1995,231(1-2):145-148
No absorption lines between 15 and 100 keV have been detected in burst spectra accumulated by BATSE. Almost 250 bursts have been inspected visually, and a computerized search has begun. Our simulations show that BATSE could indeed detect lines similar to those observed byGinga in strong bursts, and our tests of the detectors' actual capabilities demonstrate they function as understood. The apparent discrepancy between BATSE andGinga is not yet compelling, and therefore the BATSE nondetections do not invalidate theGinga detections. Nonetheless, the absence of BATSE line detections indicates a low line-occurrence frequency. 相似文献
107.
108.
Derek Sears 《Meteoritics & planetary science》2001,36(10):1291-1291
109.
Christopher Packham Keith L. Thompson Almudena Zurita Johan H. Knapen Ian Smail Robert Greimel Daniel F. M. Folha Chris Benn rew Humphrey Rene Rutten David Ciardi Matthieu Bec Richard Bingham Simon Craig Kevin Dee Derek Ives Paul Jolley Peter Moore Marti Pi i Puig Simon Rees Gordon Talbot Sue Worswick 《Monthly notices of the Royal Astronomical Society》2003,345(2):395-405
110.
Most Australian estuaries are subject to riverine discharge regimes that are highly episodic. This characteristic poses difficulties for estimating nutrient budgets of such systems based on sampling regimes that do not resolve the discharge variation and the changes in nutrient distributions that they cause. This paper presents a method for calculating nutrient budgets in estuaries having episodic hydrology. The method utilises a simple hydrodynamic transport model that is calibrated using measured salinities and which is used to describe the transport properties of the estuary as they respond to river discharge. Using this transport model, the temporal variation in nutrient concentrations within the estuary can be resolved between sampling surveys even when the discharge events are of short duration. An inverse method is then applied to calculate internal fluxes of nutrients from measurements obtained on successive sampling surveys. The approach is demonstrated through an application to the Fitzroy Estuary in Queensland, Australia. 相似文献