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91.
Nikolaos Georgakarakos 《Monthly notices of the Royal Astronomical Society》2009,392(3):1253-1263
In a series of papers, we developed a technique for estimating the inner eccentricity in hierarchical triple systems, with the inner orbit being initially circular. However, for certain combinations of the masses and the orbital elements, the secular part of the solution failed. In this paper, we derive a new solution for the secular part of the inner eccentricity, which corrects the previous weakness. The derivation applies to hierarchical triple systems with coplanar and initially circular orbits. The new formula is tested numerically by integrating the full equations of motion for systems with mass ratios from 10−3 to 103 . We also present more numerical results for short-term eccentricity evolution, in order to get a better picture of the behaviour of the inner eccentricity. 相似文献
92.
Cold related mortality among people aged over 50 in England and Wales has decreased at a rate of 85 deaths per million population per year over the period 1976–2005. This trend is two orders of magnitude higher than the increase in heat-related mortality observed after 1976. Long term changes in temperature-related mortality may be linked to human activity, natural climatic forcings, or to adaptation of the population to a wider range of temperatures. Here we employ optimal detection, a formal statistical methodology, to carry out an end to end attribution analysis. We find that adaptation is a major influence on changing mortality rates. We also find that adaptation has prevented a significant increase in heat-related mortality and considerably enhanced a significant decrease in cold-related mortality. Our analysis suggests that in the absence of adaptation, the human influence on climate would have been the main contributor to increases in heat-related mortality and decreases in cold-related mortality. 相似文献
93.
Nikolaos Th. Skoulikidis Leonidas Vardakas Ioannis Karaouzas Alcibiades N. Economou Elias Dimitriou Stamatis Zogaris 《Aquatic Sciences - Research Across Boundaries》2011,73(4):581-597
Water stress in Mediterranean countries is the result of both variable and changing climatic conditions and widespread anthropogenic
pressures. Evrotas, an intermittent river located in Southern Greece, was used as a case study to assess the impacts of water
stress on Mediterranean lotic ecosystems. Based on hydrological analyses, it was revealed that during prolonged drought years,
such as the summers of 2007 and 2008, the vast majority of the Evrotas riverbed was completely desiccated, primarily as a
result of substantial water abstraction for irrigation. The effects of desiccation on the riverine ecosystem were evaluated
using fish and macroinvertebrate assemblages according to the demands of the Water Framework Directive 2000/60/EC (WFD). Faunal
responses to water stress were assessed through comparisons of assemblages attributes in perennial and intermittent reaches
and pre-drought versus post-drought communities. Effects of hydrological disturbance on fish species richness, density, percentage
composition and size structure were more pronounced in intermittent than in perennial sites. The most obvious and immediate
impact was the elimination of populations in the intermittent reaches. However, upon flow resumption, the recolonisation from
upstream perennial reaches began, thereby permitting partial re-establishment of the depleted fish communities. Nevertheless,
the structural integrity of fish communities remained severely impacted and recovery was markedly slow. On the contrary, post-drought
macroinvertebrate assemblages were not affected by summer droughts, and the recruitment processes were rapid after flow resumption.
Our findings point to the necessity of establishing a distinction between naturally and artificially driven intermittent rivers.
We, therefore, propose the introduction of an “artificially intermittent Mediterranean river” condition within the context
of the WFD assessment applications. 相似文献
94.
95.
Daniel Moraetis Fotini Stamati Manolis Kotronakis Tasoula Fragia Nikolaos Paranychnianakis Nikolaos P. Nikolaidis 《Applied Geochemistry》2011
Koiliaris River watershed is a Critical Zone Observatory that represents severely degraded soils due to intensive agricultural activities and biophysical factors. It has typical Mediterranean soils under the imminent threat of desertification which is expected to intensify due to projected climate change. High frequency hydro-chemical monitoring with targeted sampling for Rare Earth Elements (REE) analysis of different water bodies and geochemical characterization of soils were used for the identification of hydrologic and geochemical pathways. The high frequency monitoring of water chemical data highlighted the chemical alterations of water in Koiliaris River during flash flood events. Soil physical and chemical characterization surveys were used to identify erodibility patterns within the watershed and the influence of soils on surface and ground water chemistry. The methodology presented can be used to identify the impacts of degraded soils to surface and ground water quality as well as in the design of methods to minimize the impacts of land use practices. 相似文献
96.
97.
Nikolaos?Benas Nektarios?ChrysoulakisEmail author Constantinos?Cartalis 《Theoretical and Applied Climatology》2017,130(3-4):807-816
Urban air temperature studies usually focus on the urban canopy heat island phenomenon, whereby the city center experiences higher near surface air temperatures compared to its surrounding non-urban areas. The Land Surface Temperature (LST) is used instead of urban air temperature to identify the Surface Urban Heat Island (SUHI). In this study, the nighttime LST and SUHI characteristics and trends in the seventeen largest Mediterranean cities were investigated, by analyzing satellite observations for the period 2001–2012. SUHI averages and trends were based on an innovative approach of comparing urban pixels to randomly selected non-urban pixels, which carries the potential to better standardize satellite-derived SUHI estimations. A positive trend for both LST and SUHI for the majority of the examined cities was documented. Furthermore, a 0.1 °C decade?1 increase in urban LST corresponded to an increase in SUHI by about 0.04 °C decade?1. A longitudinal differentiation was found in the urban LST trends, with higher positive values appearing in the eastern Mediterranean. Examination of urban infrastructure and development factors during the same period revealed correlations with SUHI trends, which can be used to explain differences among cities. However, the majority of the cities examined show considerably increased trends in terms of the enhancement of SUHI. These findings are considered important so as to promote sustainable urbanization, as well as to support the development of heat island adaptation and mitigation plans in the Mediterranean. 相似文献
98.
ABSTRACTThe aim of this paper is to create and present a new archaeological predictive model via GIS, incorporating what archaeologists consider the most important criterion absent of similar past models, that of critical thinking. The new model suggested in this paper is named habitation Model Trend Calculation (MTC) and is not only integrates the archaeological questions with a critical view, but it can be easily adjusted, according to the conditions or the questions concerning the archaeological community. Furthermore, it uses new topographical and geomorphological indexes such as Topographical Index (TPI), Hillslope and Landform Classification that give a new sense of the topographical and geomorphological characteristics of the examined area; therefore this model is a more powerful tool compared to older models that did not use new topographical and geomorphological indexes. The success of the created model is checked as a case study in the region of Messenia, Greece during the Mycenaean era. The region of Messenia is considered as one of the most important Mycenaean regions of Greece due to the great number and the importance of Mycenaean sites identified. For the present paper, 140 habitation sites were divided into four hierarchical categories (centers, large villages, villages, and farms) based on the extent and the plurality of the tholos tombs that exist in the broader region and according to the hierarchical categorization used by the archaeologists who have studied the area. The new predictive model presented in this work can assist in solving a series of criticisms that have been expressed in the previous studies regarding such models. Additionally, in the case of Mycenaean Messenia, the model shows excellent results in relation to the habitats of the time. 相似文献
99.
100.
Nikolaos Sabatakakis Konstantinos G. Nikolakopoulos George Papatheodorou George Kelasidis 《Earth Science Informatics》2016,9(2):183-196
A multipurpose engineering geological map of a natural heritage site including inland and offshore areas has been compiled to provide information on many aspects for land use optimization, sustainable development and environmental protection. The mapping approach was based on data provided by conventional onland field works, marine remote sensing survey and aerial photo interpretation. These data sources were integrated into a GIS platform allowing reliable mapping solutions. The geological formations encountered were grouped into individual geotechnical units according to uniformity in lithological character, while the seabed sub-bottom structure was also obtained through several seafloor thematic map compilation. Shoreline variability and evolution for a long time period (1945–2008) were also investigated and mapped. The synergistic use of the results deducted from those disciplinary surveys is finally presented in a single engineering geological map covering the onshore and offshore area. 相似文献