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631.
通过互联网将海量空间信息资源进行有效整合、存储、管理、共享及分析利用是实现面向政府、部门和社会公众地理空间信息服务的关键。结合了海量异构空间数据管理的实际需求,提出了一种Web分布式空间数据仓库体系结构,并将该体系结构应用于省级退化废弃地监控信息决策服务系统,设计了基于Web分布式空间数据仓库的省级退化废弃地监控数据管...  相似文献   
632.
网络3维GIS是近年来GIS领域的研究热点,作为数字城市的支撑技术,已成为当前GIS发展的一个重要方向.本文基于网络3维GIS的研究现状,从3维空间数据标准、网络3维可视化、分布式网络体系结构3个方面进行系统研究,并在此基础上,基于J 2EE设计并实现了一个原型系统,试图克服传统网络3维GIS中的不足.  相似文献   
633.
志留系沉积期塔里木为一地势相对平坦、水体较浅的陆表海盆地,总体充填一套碎屑海岸和三角洲体系,从下至上可划分出5个三级层序。塔中和塔北志留系沉积层序表现出明显的不对称结构,塔北地区柯坪塔格组三级层序SQ-Skp1、SQ-Skp2和SQ-Skp3沉积较完整,发育潮坪、浅海陆棚、滨岸-三角洲体系;而塔中地区缺失SQ-Skp1和SQ-Skp2层序,SQ-Skp3以潮坪体系为主,局部发育小型三角洲。与此相对,塔中地区塔塔埃尔塔格组层序SQ-Stt沉积完整,而塔北地区缺失SQ-Stt水进体系域红泥岩段。塔中和塔北志留系沉积层序的不对称结构反映了塔中和塔北构造隆升的差异和演化,奥陶末构造运动对塔中影响较大,造成塔中隆起的隆升并一直处于水上隆起,直到柯坪塔格组上段SQ-Skp3层序沉积期才淹没充填,随后持续沉降,形成了完整的塔塔埃尔塔格组层序SQ-Stt;奥陶末构造运动对塔北影响较小,西部英买力地区局部隆升,而东部持续沉降,直到柯坪塔格组沉积之后塔北东部出现较大规模隆升,形成明显的上超不整合,并造成塔塔埃尔塔格组层序SQ-Stt水进体系域红泥岩段缺失。塔中和塔北构造演化控制了盆地的沉积层序和储盖组合发育,塔中缺失下储盖组合,而塔北缺失上储盖组合,对志留系圈闭形成和油气保存具有重要的影响。  相似文献   
634.
建设网站群是电子政务发展的新思路,网站群可以实现对分散资源的有效整合。本文以地质调查网站群建设为例,对网站群概念及特点进行了阐述,提出了网站群技术架构及三个体系、三个层次的建设思想,详细分析了基于元数据的信息共享解决方案,给出了系统部署方案。  相似文献   
635.
The study of many slope channel systems has led to the development of rules in the form of observations, measurements, and hypotheses. For example, we hypothesize that high abandonment relief can strongly influence the location of the subsequent channel element and will result in an organized channel stacking pattern in which the path of the younger channel element approximates the path of the former element. The rules were developed with the objective of constructing forward models of petroleum reservoirs that are internally consistent, reproducible, and quantifiable. Channelized turbidite deposits can be interpreted to be the product of multiple cycles of waxing-waning flow energy at multiple scales. Systematic changes in the volume and caliber of turbidity flows through time trigger a fall of the equilibrium profile, which drives erosion and sediment bypass across the slope, followed by a rise of the equilibrium profile, which allows deposition on the slope of increasingly mud-rich sediments through time. In most turbidite successions, at least three scales of waxing-waning cyclicity can be interpreted: element, complex set, and sequence. The stacking pattern of channel elements within a complex set-scale cycle tends to be sequential: (1) erosion and sediment bypass; (2) amalgamation of channel elements associated with a low rate of aggradation; (3) a disorganized stacking pattern of channel elements associated with a moderate rate of aggradation; and (4) an organized stacking pattern of channel elements associated with a high rate of aggradation. Stages 1 and 2 may be absent or minor in mud-rich systems but prominent in sand-rich systems. Conversely, stage 4 may be prominent in mud-rich systems but absent in sand-rich systems. Event-based forward modeling, utilizing rules, can produce realistic architectures, such as the four stages described above. Multiple realizations and multiple alternative models can be constructed to quantitatively examine the probability of specific parameters of interest such as pore volume and connectivity.  相似文献   
636.
Submarine canyons have been the subject of intense studies in recent years because of their close link to deepwater systems. The Central Canyon is a large unusual submarine canyon in the northwestern margin of the South China Sea, has a total length of about 425 km and is oriented sub-parallel to the continental slope. Using integrated 2D/3D seismic, well log, core, and biostratigraphy data, the current study documents the stratigraphic framework, internal architecture, depositional processes, and controlling factors of the segment of the Central Canyon located in the Qiongdongnan Basin.The integrated analysis shows that the canyon fill consists of four 3rd-order sequences, SQ4, SQ3, SQ2, and SQ1. Each of them is bounded by regionally important erosional surfaces (3rd-order sequence boundaries). Within each 3rd-order sequence there is maximum regressive surface separating a regressive systems tract in the lower part and a transgressive systems tract in the upper part. Nine facies are identified and are further grouped into five depositional units, DU1 through DU5.The canyon evolved through four cut-and-fill stages, with a change from predominantly axial cut-and-fill to primarily side cut-and-fill. Axial cut-and-fill dominated during the first stage, and the slope-subparallel paleo Xisha Trough was intensely eroded by large-scale axial gravity flows. During the second cut-and-fill stage, the Central Canyon experienced both axial and side cut-and-fill. The third stage was dominated by side cut-and-fill. The canyon was eroded and fed by slope channels that transported sandy sediments from the shelf to the north during regression, and was covered by side-derived muddy MTCs during transgression. The last stage was also dominated by side cut-and-fill. The canyon, however, was filled predominantly by side-derived muddy MTCs.Evolution and depositional processes in the Central Canyon were likely controlled by slope-subparallel negative-relief induced by paleo-seafloor morphology, structural inversion of the Red River Fault and the slope-subparallel basement faults. Additionally, Coriolis force, sea-level fluctuations, high sedimentation rate, and rapid progradation of the slope also controlled and influenced the depositional processes, and internal architectures of the canyon.  相似文献   
637.
Coastal environments are susceptible to a range of impacts arising from medium and long-term climate change. However, as Ireland's population and industrial centres are concentrated in coastal locations, Ireland's coastal communities will be particularly vulnerable to the impacts of climate change. Therefore, making the best use of existing knowledge to inform the establishment of governance structures capable of facilitating the measures and actions which may soon be required is a national imperative. Coastal communities worldwide have turned to integrated coastal zone management (ICZM) as a process to deliver sustainable development. This paper explores how experience gained from ICZM implementation can be harnessed to inform the development and implementation of climate adaptation policies, with a particular focus on the coastal zone. Using the principles and conceptual basis of Earth System Governance – an emerging approach to analyse complexity of governance under global environmental change – the paper maps the architecture of ICZM and climate governance in Ireland. The research identifies the main barriers to, and opportunities for, integrated application of the two policy domains. Barriers include the fragmentation of governance structures and responsibilities of key stakeholders, a lack of coordinated support for ICZM implementation at the national level, and a relatively weak awareness of the specifics of adaptation at the local level. Opportunities include the availability of expertise gathered from phases of ICZM implementation in Ireland, which encompasses mechanisms for science-policy integration, and invaluable experience of stakeholder participation and interaction. Current political and scientific support at national and EU levels give an additional impetus to climate research and actions which may bring additional opportunities and resources to coastal governance in Ireland.  相似文献   
638.
Human pressure on mountain resources poses certain threats to their natural and man-made environment. Although there are many parameters involved, one of the driving forces behind this situation is the emphasis given so far only to the market value of mountain goods and services, ignoring the true social and environmental costs of using mountain resources. Towards this direction, the use of non-market valuation techniques could prove to be beneficial. Bearing in mind the above remarks, the paper presents an application of the Contingent Valuation Method, which aims at estimating the monetary value of a mountain settlement’s vernacular architecture, namely Metsovo. For this purpose, the survey focuses on Metsovo visitors’ willingness to pay a single annual voluntary contribution to an institution that would be founded in order to undertake all necessary actions required to preserve the town’s traditional character. The results are very promising and indicate that vernacular architecture holds a significant economic value that could justify the implementation of appropriate policies towards the protection of vernacular settlements in mountain areas.  相似文献   
639.
In this paper, we trace the history of tropical architecture beyond its supposed founding moment, that is, its institutionalization and naming‐as‐such, in the mid‐twentieth century. We note that many of the planning principles, spatial configurations and environmental technologies of tropical architecture could be traced to knowledge and practices from the eighteenth century onwards, and we explore three pre‐1950s moments of ‘tropical architecture’ in the British empire through building types such as the bungalow, military barrack and labourers' housing in the tropics. Unlike the depoliticized technical discourse of tropical architecture in the mid‐twentieth century, this earlier history shows that so‐called tropical architecture was inextricably entangled with medical and racial discourses, biopolitics and the political economy of colonialism. We argue that tropical architecture should not be understood as an entity with a fixed essence that is overdetermined by a timeless and unchanging external tropical nature. Rather, tropical architecture should be understood as a set of shifting discourses that privilege tropical nature, especially climate, in various ways as the prime determinant of built form according to different constellations of sociocultural and technoscientific conditions. We thus see ‘tropical architecture’ not as a depoliticized entity but as a power‐knowledge configuration inextricably linked to asymmetrical colonial power relations.  相似文献   
640.
基于HLA的分布式虚拟地理环境系统框架研究   总被引:1,自引:1,他引:1  
讨论了分布式虚拟地理环境的基本内容和框架需求,描述了HLA的体系结构,设计了基于HLA的分布式虚拟地理环境系统框架结构。针对设计的系统框架,讨论了其数据流和对象模型,并提出了一种实现数据协作的方法———数据先备。通过分析,认为该系统框架基本能够满足分布式虚拟地理环境的要求。  相似文献   
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