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91.
A model for the conservation of geological remains as documents   总被引:1,自引:0,他引:1  
 Geological remains are conserved mainly either together with living beings for the sake of the integrity of nature or for their economical or aesthetic value. However, they also have scientific value for the geologist to reconstruct the earth's past. For this reason we propose a model which is an application of marginal utility theory in economics and takes into account the informational utility of geological remains. Informational utility of geological remains ranges over their geological significance which is induced by the importance of the geological processes that produce them, and over their spatial extensiveness. Our model takes into account also the cost and budget of conservation and proposes to solve the differential equations of informational utility and cost simultaneously in order to obtain the optimum quantity of the remains to be conserved. Received: 9 January 1998 · Accepted: 4 February 1998  相似文献   
92.
As an essential component of lotic habitats, aquatic insects have commonly been used as bio-indicators of the ecological integrity of lotic habitats. However, recent large-scale declines have given rise to concerns about freshwater ecosystems functioning correctly. During three consecutive years, we surveyed Wadi Cherf, Upper Seybouse, Algeria, and employed the size-frequency distribution of head capsule width to sketch the life history of Oligoneuriopsis skhounate, an Ibero-Maghrebian endemic mayfly, whose distribution and ecology are not so well-known known. O. skhounate exhibited a seasonal univoltine summer cycle with growth and development taking place during the warmest period of the year (late spring to early autumn). The absence of nymphs during winter and the presence of last instar nymphs from July to November suggested a lengthy egg diapause, following the aestivo-autumnal emergence and reproduction. The study also raises the issue of freshwater biodiversity conservation in North Africa by highlighting the case of O. skhounate, acting as an indicator species of important but vulnerable aquatic ecosystems.  相似文献   
93.
Over the next several decades, arctic marine mammals will face threats from six areas of human influence: climate change, environmental contaminants, offshore oil and gas activities, shipping, hunting, and commercial fisheries. This paper reviews these factors, the nature and magnitude of the threats they pose, current scientific understanding and management of those threats, and the potential for effective conservation action. Climate change, offshore oil and gas activities, and commercial fisheries likely pose the greatest threats. Addressing the combined effects of all six factors, however, will be particularly difficult but essential to prevent declines beyond those that have already occurred.  相似文献   
94.
The Maltings at Mittagong in the Southern Highlands of New South Wales is a disused industrial site offering a challenging opportunity for adaptive re‐use. The complex operated between 1899 and 1980. Over the last decade there have been proposals to rehabilitate the buildings for new uses, but economic circumstances have intervened. This paper has several sets of objectives. The first is to provide an outline history of The Maltings, establish its place in the context of the general history of brewing and malting in NSW, and document the physical evolution of the site. The second, taking the discussion into the applied realm, is to explore the environmental heritage value of the complex, distilled in a concise statement of significance. The third objective is to illustrate how the process of historical research and heritage assessment can help identify general conservation principles which should be observed in any future development of the site. The paper provides a case study of the application of historical‐geographical research to broader objectives of heritage assessment and conservation planning.  相似文献   
95.
ROCESSES OF EPHEMERAL GULLY EROSION   总被引:2,自引:0,他引:2  
IINTRoDUCTIONEphemeralgulliesaresmallerosionalchannelsonagriculturalIandscapescausedbytheconcentrationofoverlandflowtypicallybetweentwoopposingslopes(ahollow),oftenformedduringasingIerainfaIlevent.Sincethescouredsoilvolumeisnotverylargewithinthesegullies,farmerscaneasilyrefillthem.Ingeneral,ephemeralgulliescanreappearatornearthesamelocationonayearlybasisbecausethesurfacetopograPhyofthefielddoesnotchangeappreciably.Mostephemeralgulliesoccuroncultivatedfieldswithhighlyerodiblesoils,withlit…  相似文献   
96.
Bayesian belief networks are finding increasing application in adaptive ecosystem management where data are limited and uncertainty is high. The combined effect of multiple stressors is one area where considerable uncertainty exists. Our study area, the Great Barrier Reef is simultaneously data-rich – concerning the physical and biological environment – and data-poor – concerning the effects of interacting stressors. We used a formal expert-elicitation process to obtain estimates of outcomes associated with a variety of scenarios that combined stressors both within and outside the control of local managers. There was much stronger consensus about certain stressor effects – such as between temperature anomalies and bleaching – than others, such as the relationship between water quality and coral cover. In general, the expert outlook for the Great Barrier Reef is pessimistic, with the potential for climate change effects potentially to overshadow the effects of local management actions.  相似文献   
97.
Conservation success is often predicated on local support for conservation which is strongly influenced by perceptions of the impacts that are experienced by local communities and opinions of management and governance. Marine protected areas (MPAs) are effective conservation and fisheries management tools that can also have a broad array of positive and negative social, economic, cultural, and political impacts on local communities. Drawing on results from a mixed-methods study of communities on the Andaman Coast of Thailand, this paper explores perceptions of MPA impacts on community livelihood resources (assets) and outcomes as well as MPA governance and management. The area includes 17 National Marine Parks (NMPs) that are situated near rural communities that are highly dependent on coastal resources. Interview participants perceived NMPs to have limited to negative impacts on fisheries and agricultural livelihoods and negligible benefits for tourism livelihoods. Perceived impacts on livelihoods were felt to result from NMPs undermining access to or lacking support for development of cultural, social, political, financial, natural, human, physical, and political capital assets. Conflicting views emerged on whether NMPs resulted in negative or positive marine or terrestrial conservation outcomes. Perceptions of NMP governance and management processes were generally negative. These results point to some necessary policy improvements and actions to ameliorate: the relationship between the NMP and communities, NMP management and governance processes, and socio-economic and conservation outcomes.  相似文献   
98.
I welcome the contribution by Harris to the ongoing debates around the Chagos Islands. He presents the complex tangle of issues with some clarity and relative balance that is often absent from many contributions on this subject.However, marrying scientific and political issues as Harris sets out to do is less helpful in this instance than distinguishing between the two. Blurring these boundaries can risk the future of the Chagos Marine Preservation Area (MPA) and the invaluable protection it affords the many species (including important food species) now thriving in the Chagos Archipelago. CCT works to study and protect this unique environment, and we would like to make some important distinctions clear.  相似文献   
99.
100.
International examples of interactions between Indigenous peoples and the new conservation paradigm come mainly from developing countries and suggest divisions over priorities. As a Western settler society, Australia is at a critical time in conservation and Indigenous peoples' rights. Innovative approaches to conservation are promoted. The role and influence of non-governmental organisations is increasing. Indigenous peoples' rights to land are recognised and Indigenous involvement in conservation is growing. Yet, despite Australia being considered a leader in these arenas, particularly the latter, there has been little analysis of the relationship between innovative approaches to conservation and Indigenous Australians under the new paradigm. This paper describes how the spatial manifestations of approaches under the new conservation paradigm and Indigenous land in Australia are creating new geographies. We identify geographies of overlap, dichotomy and absence. The paper identifies research needs into these geographies, including: examining the influence of ‘recognition’ in engagements between conservation and Indigenous Australians; investigating the impacts of approaches under the new paradigm such as scaling-up, territorialism and differing governance structures on Indigenous Australians; and questioning the social responsibilities of the non-governmental organisations towards Indigenous Australians.  相似文献   
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