全文获取类型
收费全文 | 115篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
大气科学 | 17篇 |
地球物理 | 33篇 |
地质学 | 46篇 |
海洋学 | 8篇 |
天文学 | 4篇 |
综合类 | 1篇 |
自然地理 | 13篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 3篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 11篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 7篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
排序方式: 共有122条查询结果,搜索用时 46 毫秒
71.
Martin?IvanovEmail author Kirsten?Warrach-Sagi Volker?Wulfmeyer 《Theoretical and Applied Climatology》2018,132(1-2):239-261
A new approach for rigorous spatial analysis of the downscaling performance of regional climate model (RCM) simulations is introduced. It is based on a multiple comparison of the local tests at the grid cells and is also known as ‘field’ or ‘global’ significance. The block length for the local resampling tests is precisely determined to adequately account for the time series structure. New performance measures for estimating the added value of downscaled data relative to the large-scale forcing fields are developed. The methodology is exemplarily applied to a standard EURO-CORDEX hindcast simulation with the Weather Research and Forecasting (WRF) model coupled with the land surface model NOAH at 0.11 ° grid resolution. Daily precipitation climatology for the 1990–2009 period is analysed for Germany for winter and summer in comparison with high-resolution gridded observations from the German Weather Service. The field significance test controls the proportion of falsely rejected local tests in a meaningful way and is robust to spatial dependence. Hence, the spatial patterns of the statistically significant local tests are also meaningful. We interpret them from a process-oriented perspective. While the downscaled precipitation distributions are statistically indistinguishable from the observed ones in most regions in summer, the biases of some distribution characteristics are significant over large areas in winter. WRF-NOAH generates appropriate stationary fine-scale climate features in the daily precipitation field over regions of complex topography in both seasons and appropriate transient fine-scale features almost everywhere in summer. As the added value of global climate model (GCM)-driven simulations cannot be smaller than this perfect-boundary estimate, this work demonstrates in a rigorous manner the clear additional value of dynamical downscaling over global climate simulations. The evaluation methodology has a broad spectrum of applicability as it is distribution-free, robust to spatial dependence, and accounts for time series structure. 相似文献
72.
Kirsten van Zuilen Thomas F. Nägler Thomas D. Bullen 《Geostandards and Geoanalytical Research》2016,40(4):543-558
The interest in variations of barium (Ba) stable isotope amount ratios in low and high temperature environments has increased over the past several years. Characterisation of Ba isotope ratios of widely available reference materials is now required to validate analytical procedures and to allow comparison of data obtained by different laboratories. We present new Ba isotope amount ratio data for twelve geological reference materials with silicate (AGV‐1, G‐2, BHVO‐1, QLO‐1, BIR‐1, JG‐1a, JB‐1a, JR‐1 and JA‐1), carbonate (IAEA‐CO‐9) and sulfate matrices (IAEA‐SO‐5 and IAEA‐SO‐6) relative to NIST SRM 3104a. In addition, two artificially fractionated in‐house reference materials BaBe12 and BaBe27 (δ137/134Ba = ?1.161 ± 0.049‰ and ?0.616 ± 0.050‰, respectively) are used as quality control solutions for the negative δ‐range. Accuracy of our data was assessed by interlaboratory comparison between the University of Bern and the United States Geological Survey (USGS). Data were measured by MC‐ICP‐MS (Bern) and TIMS (USGS) using two different double spikes for mass bias correction (130Ba–135Ba and 132Ba–136Ba, respectively). MC‐ICP‐MS measurements were further tested for isobaric and non‐spectral matrix effects by a number of common matrix elements. The results are in excellent agreement and suggest data accuracy. 相似文献
73.
74.
Kirsten Hastrup 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(2):181-189
Geografisk Tidsskrift—Danish Journal of Geography 109(2):181–189, 2009 The paper will explore the sense of place in the Thule district, Northern Greenland, including the emotional topography by which people live. The analytical framework is the notion of a nomadic landscape, drawing from the essay on nomadology by Deleuze & Guattari (2004). The nomadic landscape is constituted by a network of spatial centres—or points of reference—from each of which an infinite spatial realm takes its beginning. The ambition is to demonstrate how, in a nomadic landscape, movement is integral to memory, sociability and experience; this is vital to the understanding of present day responses to the reduced mobility owing to changing weather and ice conditions in the Thule district. 相似文献
75.
Ada Pastor Louis J. Skovsholt Kirsten S. Christoffersen Naicheng Wu Tenna Riis 《水文研究》2021,35(10):e14369
Climate change is causing drastic landscape changes in the Arctic, but how these changes modify stream biogeochemistry is not clear yet. We examined how catchment properties influence stream nitrogen (N) and dissolved organic carbon concentrations (DOC) in a high-Arctic environment. We sampled two contrasting headwater streams (10–15 stations over 4.8 and 6.8 km, respectively) in Northeast Greenland (74°N). We characterized the geomorphology (i.e., bedrock, solifluction and alluvial types) and the vegetation (i.e., barren, fell field, grassland and tundra types) cover of each subcatchment area draining into each sampling station and collected water samples for hydrochemistry characterization. The two sampled streams differed in geomorphology and vegetation cover in the catchment. Aucellaelv catchment was mostly covered by a ‘bedrock’ geomorphology (71%) and ‘fellfield’ vegetation (51%), whereas Kæerelv was mostly covered by ‘alluvial’ geomorphology (65%) and ‘grassland’ and ‘tundra’ vegetation (42% and 41% respectively). Hydrochemistry also differed between the two study streams, with higher concentrations of inorganic N forms in Aucellaelv and lower DOC concentrations, compared to Kærelv. The results from the linear mixed model selection showed that vegetation and geomorphology had contrasting effects on stream hydrochemistry. Subcatchments with higher solifluction sheets and limited vegetation had higher nitrate concentrations but lower DOC concentrations. Interestingly, we also found high variability on the production and removal of nitrate across subcatchments. These results indicate landscape controls to nutrient and organic matter exports via flow paths, soil organic matter stocks and nutrient retention via terrestrial vegetation. Moreover, the results suggest that climate change induced alterations to vegetation cover and soil physical disturbance in high-Arctic catchments will affect stream hydrochemistry, with potential effects in stream productivity, trophic relations as well as change of solute export to downstream coastal areas. 相似文献
76.
Kirsten Valentine Cadieux 《GeoJournal》2011,76(4):341-363
This paper explores different ways that the category of nature is used in addressing landscape changes associated with exurbia
and exurbanization. Nature is an important category in the practices and representations that residents and planners use to
construct and maintain exurban landscapes. However, common ways of mobilizing nature in exurban planning discourses often
obstruct better discussion, rather than facilitate it. Invoking nature can make planning processes more difficult by providing a means
for naturalizing planning decisions and also by exacerbating struggles over whose nature will be managed in what ways. More
explicitly framing what is meant by nature in exurban planning may improve discussion of landscape problems associated with
sprawl. The goal of this paper is to contribute to creating a framework for more actively contextualizing how “nature” is
used in discourses relating to exurbanization. I suggest that such a framework would need to consider—and make explicit—themes
such as the four that I discuss in this paper: (1) the centrality of the production of nature to exurban landscapes; (2) multiple
meanings of nature that are often confused; (3) ways that normative statements about nature tend to be unquestioned in exurban
planning; and (4) the simultaneous difficulty and usefulness of critiquing and “denaturalizing” both material and discursive
nature. Explicit conversations about the role and representation of nature within residents’ and managers’ land-use practices
and ideologies could create opportunities for dialogue between residents, planners, and academics about the valuation of and
preferences for constructing particular landscapes, especially in addressing problematic aspects of the phenomena of “amenity
migration” and “sprawl.” 相似文献
77.
Herwig Marbler Kirsten P. Erickson Michael Schmidt Christof Lempp Herbert Pöllmann 《Environmental Earth Sciences》2013,69(6):1981-1998
The geochemical and geomechanical behaviour of reservoir rocks from deep saline aquifers during the injection and geological storage of CO2 is studied in laboratory experiments. A combination of geochemical and geomechanical studies was carried out on various sandstones from the North German Basin. After the mineralogical, geochemical and petrophysical characterization, a set of sandstone samples was exposed to supercritical (sc)CO2 and brine for 2–4 weeks in an autoclave system. One sample was mineralogically and geochemically characterised and then loaded in a triaxial cell under in situ pressure and temperature conditions to study the changes of the geomechanical rock properties. After treatment in the autoclaves, geochemical alterations mainly in the carbonate, but also in the sheet silicate cements as well as in single minerals of the sandstones were observed, affecting the rocks granular structure. In addition to partial solution effects during the geochemical experiments, small grains of secondary carbonate and other mineral precipitations were observed within the pore space of the treated sandstones. Results of additional geomechanical experiments with untreated samples show that the rock strength is influenced by the saturation degree, the confining pressure, the pore fluid pressure and temperature. The exposure to pure scCO2 in the autoclave system induces reduced strength parameters, modified elastic deformation behaviour and changes of the effective porosity in comparison to untreated sandstone samples. Experimental results show that the volume of pore fluid fluxing into the pore space of the sandstones clearly depends on the saturation level of the sample. 相似文献
78.
H. Ducati S. Kalbitzer J. Kiko T. Kirsten H. W. Müller 《Earth, Moon, and Planets》1973,8(1-2):210-227
The linear heating technique was applied to study the release of solar wind implanted He and Ne in single glass spherules and minerals of lunar soils. In addition, the diffusion of rare gases artificially implanted into simulated lunar glass was investigated. Activation energies derived for lunar glasses are much higher than for virginal glasses of similar chemical composition. Volume diffusion of the lunar surface cannot explain the high retentivity for the trapped gases. It is expermentally shown that various types of radiation damage are of paramount importance to the understanding of the secondary alterations of elemental abundances after solar wind implantation on the lunar surface.Paper dedicated to Prof. Harold C. Urey on the occasion of his 80th birthday on 29 April 1973. 相似文献
79.
Martin Bruckner Stefan Giljum Christian Lutz Kirsten Svenja Wiebe 《Global Environmental Change》2012,22(3):568-576
Production and consumption activities in industrialized countries are increasingly dependent on material and energy resources from other world regions and imply significant economic and environmental consequences in other regions around the world. The substitution of domestic material extraction and processing through imports is also shifting environmental burden abroad and thus extends the responsibility for environmental impacts as well as social consequences from the national to the global level. Based on the results of the Global Resource Accounting Model, this paper presents the first trade balances and consumption indicators for embodied materials in a time series from 1995 to 2005. The model includes 53 countries and two world regions. It is based on the 2009 edition of the input–output tables and bilateral trade data published by the Organisation for Economic Co-operation and Development (OECD) and is extended by physical data on global material extraction. The results quantify the global shift of embodied material resources from developing and emerging countries to the industrialized world. In addition to the level of industrialization and wealth, population density is identified as an important factor for the formation of physical trade patterns. Exports of embodied materials of less densely populated countries tend to surpass their imports, and vice versa. We also provide a quantitative comparison between conventionally applied indicators on material consumption based on direct material flows and indicators including embodied material flows. We show that the difference between those two indicators can be as much as 200%, calling for an adjustment of conventional national material flow indicators. Multi-regional input–output models prove to be a useful methodological approach to derive globally consistent and comprehensive data on material embodiments of trade and consumption. 相似文献
80.
Challenges of analyzing multi-hazard risk: a review 总被引:9,自引:6,他引:3
Melanie S. Kappes Margreth Keiler Kirsten von Elverfeldt Thomas Glade 《Natural Hazards》2012,64(2):1925-1958
Many areas of the world are prone to several natural hazards, and effective risk reduction is only possible if all relevant threats are considered and analyzed. However, in contrast to single-hazard analyses, the examination of multiple hazards poses a range of additional challenges due to the differing characteristics of processes. This refers to the assessment of the hazard level, as well as to the vulnerability toward distinct processes, and to the arising risk level. As comparability of the single-hazard results is strongly needed, an equivalent approach has to be chosen that allows to estimate the overall hazard and consequent risk level as well as to rank threats. In addition, the visualization of a range of natural hazards or risks is a challenging task since the high quantity of information has to be depicted in a way that allows for easy and clear interpretation. The aim of this contribution is to give an outline of the challenges each step of a multi-hazard (risk) analysis poses and to present current studies and approaches that face these difficulties. 相似文献