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161.
The ecologically and socio-economically important marine ecosystems of Europe are facing severe threats from a variety of human impacts. To mitigate and potentially reverse some of these impacts, the European Union (EU) has mandated the implementation of the Marine Strategy Framework Directive (MSFD) in order to achieve Good Environmental Status (GES) in EU waters by 2020. The primary initiative for achieving GES is the implementation of coherent networks of marine protected areas (MPAs). Marine reserves are an important type of MPA in which no extraction is allowed, but their usefulness depends upon a number of ecological, management, and political factors. This paper provides a synthesis of the ecological effects of existing European marine reserves and the factors (social and ecological) underlying their effectiveness. Results show that existing European marine reserves foster significant positive increases in key biological variables (density, biomass, body size, and species richness) compared with areas receiving less protection, a pattern mirrored by marine reserves around the globe. For marine reserves to achieve their ecological and social goals, however, they must be designed, managed, and enforced properly. In addition, identifying whether protected areas are ecologically connected as a network, as well as where new MPAs should be established according to the MSFD, requires information on the connectivity of populations across large areas. The adoption of the MSFD demonstrates willingness to achieve the long-term protection of Europe's marine ecosystems, but whether the political will (local, regional, and continent wide) is strong enough to see its mandates through remains to be seen. Although the MSFD does not explicitly require marine reserves, an important step towards the protection of Europe's marine ecosystems is the establishment of marine reserves within wider-use MPAs as connected networks across large spatial scales.  相似文献   
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163.
This paper presents the status of summer oxygen conditions in estuarine and coastal waters around Ireland between 2003 and 2007. Of the 95 water bodies surveyed, 85 had oxygen levels sufficient to support aquatic life. This corresponds to a surface area of 3125 km2 or 99.4% of the total area assessed. Ten water bodies, representing a surface area of 20.2 km2, were deficient in oxygen but still capable of supporting most aquatic life. No evidence of hypoxia (<2.0 mg/l O2) or anoxia (<0.2 mg/l O2) was found. Dissolved oxygen conditions in a number of estuaries continue to improve, probably due to improved municipal waste water treatment. The implementation of measures contained in both the Nitrates and Urban Waste Water Treatment Directives, together with those of the Water Framework Directive, should ensure areas of oxygen deficiency are eliminated from Irish waters.  相似文献   
164.
Artificial drainage of forested wetlands to increase timber production has profoundly altered the hydrology of North-European landscapes during the 20th century. Nowadays, drainage ditches and small dredged streams can comprise most fluvial water bodies there, but the resulting ecological effects are poorly documented. In the current study, we explored, using fish as an indicator group, consequences of the transformation of natural stream networks to a mixture of natural and artificial watercourses. We asked whether the transformation results in impoverishment, enrichment or re-assembling of the communities both at watercourse and the landscape scales. We sampled fish in 98 sites in five well-forested regions in Estonia where ditches formed 83–92%, dredged streams 4–7%, and natural streams 3–10% of the total length of small watercourses. Based on a total of 6370 individual fish of 20 species, we found that, compared to natural streams, ditches had an impoverished fauna at both scales and both in terms of species richness and assemblage composition. Only natural streams hosted characteristic species (with Barbatula barbatula, Lampetra planeri and Lota lota emerging as significant indicators), while dredged streams had intermediate assemblages. The habitat factors explaining those drainage-related differences included a reduced flow velocity, loss of stream channel variability, less transparent water, and abundant aquatic vegetation. Hence, for stream-dwelling fish, drained forest landscapes represent degraded habitats rather than novel ecosystems, which contrasts with the transformation of terrestrial assemblages. Future studies should address whether that reflects the situation for whole aquatic assemblages, and how is the functioning of the hydrological systems affected. We suggest that the critical management issues for environmental mitigation of ditching effects on fish include basin scale spatial planning, protecting of the remaining natural streams, and rehabilitation of ditch channels in flat landscapes lacking beavers.  相似文献   
165.
文章针对海上风电工程结构安全监测的需求,在系统回顾了目前的主要监测现状及存在的监测难点的基础上,初步构建了水上、水下一体化安全监测体系基础框架,阐述了主要的工作流程,重点探讨了海上风电工程安全监测中的精密单点定位(PPP)技术、高程传递、多传感器集成、精密水下定位技术、水下摄像机标校、水下三维激光点云快速建模、水下桩基全景影像与点云数据匹配、多波束与侧扫声呐数据融合等关键技术,以期为海上风电工程结构设施管控、变化监控和防灾减灾提供新的应急方案和技术支撑。  相似文献   
166.
The abiotic typology of Polish lakes, compliant with the requirements of the EU Directive 2000/60/EC (Water Framework Directive), was developed in 2004 under the commission of the Ministry of the Environment. Based on the combination of the obligatory typological criteria from Annex II of the WFD and one additional factor, all Polish lakes larger than 0.5 km2 were assigned to 13 abiotic types. This typology reflected the diversity of abiotic conditions and was assumed to be tested and validated for its ecological relevance on the basis of biological data obtained thereafter. The first ten years of its application proved the high usability of this typology for lake classification of ecological status on the one hand, while on the other hand, it allowed to gather experiences and to detect deficiencies and errors considered in the verification process. In 2015, the abiotic typology of Polish lakes was verified. Above all, verification involved an analysis of the justification of lake eco-regional division and refinement of water stratification criteria, as these two issues have been questioned in the current typology. Data on physicochemical properties, phytoplankton, macrophytes and benthic diatoms obtained from the state lake monitoring conducted in the years 2007–2013 were used to verify the ecological relevance of the typological criteria. Typological criteria used in the verified lake typological scheme were essentially the same as those used in 2004. However, the number of lake types has been reduced from the previous 13 to seven, mainly due to the withdrawal from the lake division based on eco-regions. Moreover, the more specific criteria for determining the water mixing type were established. The new lake typology is expected to be implemented in routine monitoring and water management in Poland in the forthcoming River Basin Management Plan 2021–2027.  相似文献   
167.
物理海洋数据具有多维、时空和海量等特征,主要以NetCDF结构化文件格式进行存储。然而,在分布式环境中,结构化文件存在数据块寻址困难、边界不易判定等问题,制约着大数据场景下的存储及应用。论文设计基于HDFS+Spark的NetCDF物理海洋数据云存储方案,首先采用HDFS分布式存储技术存储和管理物理海洋数据;并设计基于Spark并行计算框架的数据分片方案,复写读取接口获取分布式环境下的NetCDF文件数据块地址,实现了物理海洋数据的高效率存储与查询分析。选取中国海域100 a时长的物理海洋数据进行波高-周期散布图统计实验。结果表明:在数亿级记录数条件下,文中方法可将查询分析耗时由集中式文件存储方式的2 300 s缩短至50 s内,效率较集中式文件存储方式提升95%以上,验证了该方法的正确性和有效性。  相似文献   
168.
适应性球体退化八叉树格网及其编码方法   总被引:1,自引:1,他引:0  
球体退化八叉树格网(SDOG)为具有经纬一致性、正交、粒度近似、非重叠、多层次性及多分辨率的三维全球空间格网(GSG),有望成为地球系统科学、全球GIS乃至数字地球的空间基础框架,但不便处理半径及球面维度上的分辨率非同步变化问题。该文在SDOG基础上沿某一方向进行独立递归细分,构建了一个能适应非同步变化的多分辨率的球体GSG———适应性SDOG,提出了其耦合退化Z(CDZ)曲线填充编码方法;并以NCEP提供的温度数据为实验,实现了基于适应性SDOG的全球大气温度场三维建模与可视化。结果表明:适应性SDOG具有更好的适应能力,能有效处理分辨率非同步变化问题,提高了SDOG作为全球空间基础框架的应用性能。  相似文献   
169.
This paper proposes a landscape planning and management method for river basins within the context of the European Landscape Convention (ELC) and European Water Framework Directive (WFD). This method has been applied to the Zir Valley in Ankara, Turkey. Landscape planning is identified by the ELC (European Treaty Series No. 176, 2000) as an important, forward-looking action to enhance, restore or create landscapes. The ELC also states that landscape management should promote sustainable development to ensure the non-degradation of landscapes and to help harmonize inevitable changes. The WFD (Directive 2000/60/EC of the European Parliament and of the Council, 2000) is a set of guidelines for managing large bodies of water. Its principle directive is to identify water bodies and the adjacent land areas that influence, and are influenced by, those water bodies. These are called River Basin Districts, and act as essential physiographic landscape units. While several regulations related to environmental planning, and used on a national as well as European basis, tend to utilize the same tools in practice, there are dissimilarities in how they are specifically applied and little effort is being made to promote a cooperative approach. In this paper, a National Approach for River Basin Management is proposed. This approach, which includes a landscape planning and management method based on landscape form and function, was developed to address the common purposes of the ELC and WFD.  相似文献   
170.
The relentless loss of biological diversity, which will have a direct impact on human society and degrade ecosystem buffers against the extremes of climate perturbation, requires a strong global governance response. Of the numerous international legal instruments relating to the protection of nature, the Convention on Biological Diversity (CBD) is the most comprehensive. This paper examines its current emphasis on global biodiversity targets to extend our understanding of its trajectory, and its evolving nature as an instrument of global governance. We review CBD documents, and early examinations of its emergent character, in the context of the distinction between hard and soft law approaches, and combine analysis on the issue of targets from the literature on development, climate change and conservation biology. We emphasise that the CBD, created as a hard law instrument with a framework character, had the clear facility to develop subsidiary hard law instruments in the form of protocols but has not significantly followed this route. We document how its approach - which has been typically ‘soft’, as exemplified by its focus on global biodiversity targets which are not backed up by obligations - suggests it operates de facto as policy rather than an instrument requiring state action. The adoption of global targets has parallels with other initiatives within global governance and may influence international political agendas, but they have failed to provide practical instruments for national implementation. Conditions may now exist for the CBD to develop focussed hard legal instruments in specific areas of its wide remit that support realistic targets.  相似文献   
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