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171.
Planning versus youth: Stamping out spatial unruliness in Harare   总被引:1,自引:0,他引:1  
Amin Y. Kamete   《Geoforum》2008,39(5):1721-1733
The paper examines the illegal occupation and use of urban spaces by Harare’s youth and the ensuing tussles with the repressive machinery of the local authority and the nation-state. It analyses efforts by planning to contain rampant spatial unruliness. The paper maps the patterns of official hostile responses to the illegal activities of the youth whose daily routines inevitably entail the disregard of the spatial planning framework as reflected in existing legal and regulatory controls. The analysis reveals the reliance by the urban planning and management system on the use of force and violence, a feat made possible by the mobilisation of the repressive state apparatus. The discussion argues that what comes out in the relationship between the order-imposing planning system and the regulation-flouting youth is a situation that can largely be comprehended by turning to the non-progressive side of planning.  相似文献   
172.
Natural Hazards - Maintaining sustainability in rainfed wheat production under changing climate is a grave concern for food security in Algeria. This study aims to assess the impact of future...  相似文献   
173.
We have followed the chemistry of W3 IRS4, as one of the most famous regions with a chemistry similar to that found in quiescent molecular clouds. Here the time scale, since star formation, has probably been long enough for the gas-phase ion-molecule chemistry to become dominant again. We have constructed a reaction system containing the chemical families of H, C, O, N, S and metals (Me:Fe, Mg, Na and Si). A total of 282 species have been included and a network of 1270 reactions has been used. The chemical kinetic equations were integrated as a function of pseudo-time-dependent approach. The evolution of the different chemical species are followed in models of density n equal to 106 cm-3 and temperature T equal to 55 K. Different initial abundances have been assumed. Our results are in reasonable agreement with the observation, especially in Model 6. The resulting molecular abundances are compared with those obtained in the intermediate mass star NGC 2264 IRS1, as well as the low mass IRAS 16293-2422. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
174.
A chemical evolution of W3 IRS5 have been studied during J-type shock. We modified our code of for one-dimensional J-type shock to satisfy the physical conditions of W3 IRS5. The chemical rate equations and the hydrodynamics of shocks are integrated simultaneously. We find that, a shock of speed V s = 10 km s-1 and magnetic induction B=4.1×10-6 Gauss, propagate into molecular gas density of n=104cm-3, and with initial temperature of 30 K (pre shock) satisfy the physical conditions of W3 IRS5. The results using the extensive chemical network with the most updating reaction rates show that the calculated fractional abundances are in agreement with observation. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
175.
Global land cover (LC) maps have been widely employed as the base layer for a number of applications including climate change, food security, water quality, biodiversity, change detection, and environmental planning. Due to the importance of LC, there is a pressing need to increase the temporal and spatial resolution of global LC maps. A recent advance in this direction has been the GlobeLand30 dataset derived from Landsat imagery, which has been developed by the National Geomatics Center of China (NGCC). Although overall accuracy is greater than 80%, the NGCC would like help in assessing the accuracy of the product in different regions of the world. To assist in this process, this study compares the GlobeLand30 product with existing public and online datasets, that is, CORINE, Urban Atlas (UA), OpenStreetMap, and ATKIS for Germany in order to assess overall and per class agreement. The results of the analysis reveal high agreement of up to 92% between these datasets and GlobeLand30 but that large disagreements for certain classes are evident, in particular wetlands. However, overall, GlobeLand30 is shown to be a useful product for characterizing LC in Germany, and paves the way for further regional and national validation efforts.  相似文献   
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177.
The role of forests is being actively considered under the agenda of REDD+ (Reducing Emissions from Deforestation and Forest Degradation plus) aimed at reducing emissions related to changes in forest cover and forest quality. Forests in general have undergone negative changes in the past in the form of deforestation and degradation, while in some countries positive changes are reported in the form of conservation, sustainable management of forests and enhancement of carbon stock. The present study in the Kashmir Himalayan forests is an effort to assess historical forest cover changes that took place from 1980 to 2009 and to predict the same for 2030 on the basis of past trend using geospatial modeling approach. Landsat data (Multispectral Scanner (MSS), Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM+)) was used for the years 1980, 1990 and (2001, 2009) respectively and change detection analysis between the dates was performed. The maps generated were validated through ground truthing. The study area (3375.62 km2) from 1980-2009 has uffered deforestation and forest degradation of about 126 km2 and 139.02 km2 respectively which can be claimed under negative options of REDD+, while as the area that experienced no change (1514 km2) can be claimed under conservation. A small area (23.31 km2) observed as positive change can be claimed under positive options. The projected estimates of forest cover for 2030 showed increased deforestation and forest degradation on the basis of trend analysis using Cellular Automata (CA) Markov modeling. Despite the fact that country as a whole has registered a net positive change in the past few decades, but there are regions like Kashmir region of western Himalaya which have constantly undergoing deforestation as well as degradation in the past few decades.  相似文献   
178.
Natural Resources Research - Additional and complementary mineral exploration boreholes are often designed to obtain valuable information about mineralized intervals with the least cost. In this...  相似文献   
179.
    
Natural Resources Research - This study developed a new perspective of artificial neural networks using dimensional analysis to be applicable to certain prediction problems. To this end,...  相似文献   
180.
    
The Cimmerian Terrane, part of which forms the Central Iranian Plateau, is one of several continental fragments produced during the early- to mid-Palaeozoic breakup of the northern margin of Gondwana. Magmatic evidence for the final separation of the Terrane from Gondwana and formation of the intervening Neo-Tethys Ocean is preserved in the Misho Mountains SW of Marand, NW Iran. A small (30 km2) body of subalkaline granite intruding Precambrian sedimentary rocks of the Kahar Formation has numerous chemical features that identify it as an A-type granite, including high Ga/Al, K2O + Na2O, FeOt/(FeOt + MgO) and incompatible elements (LILE and HFSE), and low CaO and P2O5. Such features are consistent with the asthenospheric upwelling above a rising mantle plume. Zircon ages of 350.8 ± 3.0, 345.4 ± 3.2, and 343.6 ± 4.0 Ma measured on three samples of the Misho A-type granite along with the same granites exposed in the western domain (Herris area, 306 Ma) reveal that the crystallization process occurred sequentially in different stages. The obtained ages record detachment of the Cimmerian Terrane from Gondwana and the initiation of Neo-Tethys at least in the Early Carboniferous, significantly earlier than previous researchers have proposed.  相似文献   
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