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231.
Einfach sprachlos but not simply speechless: language(s), thought and practice in the social sciences 总被引:1,自引:1,他引:1
Based on the authors' experiences as German-language speakers working at different stages of their careers within Anglo-American human geography, this article reflects on the workings of (foreign) language, not only through academic publications but more widely in research contexts and everyday work. This is done by three personal observations, highlighting the relevance of (foreign) language interactions in terms of research practice as well as the poetics and politics of language. We argue that a wider recognition of language in the practical terms of academic work is called for in the light of an increasing 'internationalization' of academia. 相似文献
232.
Karin Holmgren Julia A. Lee-Thorp Gordon R. J. Cooper Katarina Lundblad Timothy C. Partridge Louis Scott Riashna Sithaldeen A. Siep Talma Peter D. Tyson 《Quaternary Science Reviews》2003,22(21-22):2311-2326
Data from stalagmites in the Makapansgat Valley, South Africa, document regional climatic change in southern Africa in the Late Pleistocene and Holocene. A new TIMS U-series dated stalagmite indicates speleothem growth from 24.4 to 12.7 ka and from 10.2 to 0 ka, interrupted by a 2.5 ka hiatus. High-resolution oxygen and carbon stable isotope data suggest that postglacial warming was first initiated 17 ka, was interrupted by cooling, probably associated with the Antarctic Cold Reversal, and was followed by strong warming after 13.5 ka. The Early Holocene experienced warm, evaporative conditions with fewer C4 grasses. Cooling is evident from 6 to 2.5 ka, followed by warming between 1.5 and 2.5 ka and briefly at AD 1200. Maximum Holocene cooling occurred at AD 1700. The new stalagmite largely confirms results from shorter Holocene stalagmites reported earlier. The strongest variability superimposed on more general trends has a quasi-periodicity between 2.5 and 4.0 ka. Also present are weaker 1.0 ka and 100-year oscillations, the latter probably solar induced. Given similarities to the Antarctic records, the proximate driving force producing millennial- and centennial-scale changes in the Makapansgat record is postulated to be atmospheric circulation changes associated with change in the Southern Hemisphere circumpolar westerly wind vortex. 相似文献
233.
JuliaBoike OlafIppisch 《冰川冻土》2002,24(5):538-543
Mud boils, classified as non-sorted circles, are a common patterned ground phenomenon of permafrost areas. They typically consist of a bare circle center of cryoturbated soil and are surrounded by vegetation on more stable soil. The objectives are to examine differences in seasonal hydrologic and thermal dynamic across this gradient of cryoturbation, i.e. the region below the organic border and the mud center. We installed instruments in a mud boil at a site close to Ny-@lesund, Spitsbergen, in September 1998. The bare soil circle center ranges about 1 m in diameter and is surrounded by a vegetated border consisting of a mixture of low vascular plants, mosses and lichens. Fine soil (>95% clay and silt) in the lower part of the profile is overlain by coarser grained material (silt and sand). The grain size distribution also suggests an upwelling of fine material in the center of the circle. Temperature and moisture sensors were installed over a vertical 1 m×1 m profile and hourly data recording started in September 1998. Surface irregularities, as well as variations of grain size and moisture, create a non-uniform thermal and hydrologic dynamic. We qualitatively analyze this dynamic with respect to the mud boils physical stability. 相似文献
234.
Re‐enlivening the Indian Ocean through contemporary trade: East African traders searching for new markets in Jakarta
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Julia Verne 《Singapore journal of tropical geography》2017,38(1):123-138
While much has been written about the history of mobility and trade in the Indian Ocean, recent trading connections between Eastern Africa and Asia have so far only gained very little attention. However, in Zanzibar alone, hundreds of traders regularly embark on journeys reviving old routes and further develop them, in order to take advantage of the way the global economy works today. By providing an ethnographic account of such a journey undertaken by four Zanzibari traders to Jakarta, this article gives an insight into the organization, calculations and imaginations involved in contemporary Indian Ocean trading networks. Although this trade journey clearly marks a new form of translocal mobility among Zanzibari traders, this mobile ethnography highlights how the journey is at the same time closely linked to, evokes and enlivens very old processes of mobility across the Indian Ocean, thus highlighting the dialectics between old and new mobilities, and between familiarity and strangeness. 相似文献
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We assessed spatial and temporal variability in the physical environment of a subarctic estuary, and examined concurrent patterns of chlorophyll α abundance (fluorescence), and zooplankton and forage fish community structure. Surveys were conducted in lower Cook Inlet, Alaska, during late July and early August from 1997 through 1999. Principle components analysis (PCA) revealed that spatial heterogeneity in the physical oceanographic environment of lower Cook Inlet could be modeled as three marine-estuarine gradients characterized by temperature, salinity, bottom depth, and turbidity. The gradients persisted from 1997 through 1999, and PCA explained 68% to 92% of the variance in physical oceanography for each gradient-year combination. Correlations between chlorophyll α abundance and distribution and the PCA axes were weak. Chlorophyll was reduced by turbidity, and low levels occurred in areas with high levels of suspended sediments. Detrended correspondence analysis (DCA) was used to order the sample sites based on species composition and to order the zooplankton and forage fish taxa based on similarities among sample sites for each gradient-year. Correlations between the structure of the physical environment (PCA axis 1) and zooplankton community structure (DCA axis 1) were strong (r = 0.43-0.86) in all years for the three marine-estuarine gradients, suggesting that zooplankton community composition was structured by the physical environment. The physical environment (PCA) and forage fish community structure (DCA) were weakly correlated in all years along Gradient 2, defined by halocline intensity and surface temperature and salinity, even though these physical variables were more important for defining zooplankton habitats. However, the physical environment (PCA) and forage fish community structure (DCA) were strongly correlated along the primary marine-estuarine gradient (#1) in 1997 (r = 0.87) and 1998 (r = 0.82). The correlation was poor (r = 0.32) in 1999, when fish community structure changed markedly in lower Cook Inlet. Capelin (Mallotus villosus), walleye pollock (Theragra chalcogramma), and arrowtooth flounder (Atheresthes stomias) were caught farther north than in previous years. Waters were significantly colder and more saline in 1999, a La Niña year, than in other years of the study. Interannual fluctuations in environmental conditions in lower Cook Inlet did not have substantial effects on zooplankton community structure, although abundance of individual taxa varied significantly. The abundance and distribution of chlorophyll α, zooplankton and forage fish were affected much more by spatial variability in physical oceanography than by interannual variability. Our examination of physical-biological linkages in lower Cook Inlet supports the concept of “bottom-up control,” i.e., that variability in the physical environment structures higher trophic-level communities by influencing their distribution and abundance across space. 相似文献
238.
从加拿大ACAP项目看非集中式海岸带综合管理的有效性 总被引:5,自引:0,他引:5
海岸带地区因其独特的地学与生态系结构而具有丰富的资源和巨大的开发价值。据统计,世界上有2/3的城市座落于海岸带地区,海岸带地区人口远比内地人口增长得快。经济发展和人口增长给海岸带带来的生态环境的压力不断加重,引起了一系列问题。如:海洋污染、渔业减产、海洋生物栖息地丧失、海域使用冲突、管理机构之间的冲突等。这些问题简单地沿用以往的行业管理已难以解决,由此,70年代起在 相似文献
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240.
Walking tours are common practice in urban tourism and are, historically, one of the earliest examples of urban tourism. Due to a rise in the demand for so-called “authentic” experiences in tourism in recent years, there has been a growth in different types of cultural walking tours, particularly in poor neighborhoods of major cities globally. The increase in these tours brings to light a number of questions concerning the ethics of taking people through poorer areas, where relatively vulnerable populations live and work. This paper highlights some of the potential ethical concerns around this type of tourism, while also mentioning the potential benefits. 相似文献