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341.
Chen Ming Yan Guangsheng Department of Geology China University of Geosciences Beijing Fan Jizhang Li Jingchao Geomathematics Institute Changchun University of Science Technology Changchun 《中国地质大学学报(英文版)》2000,11(2)
INTRODUCTIONGeochemists need to study the spatial distribution of theassociations of the geochemical elements(AGE) to delineatethe geochemical blocks or recognize geochemical anomalies inregional geochemical exploration.Regional geochemical divi-sion (RGD) is a mapping technique for the division of thestudy area into slices where the natural AGEs are relativelysimple and uniform.A practical approach to RGD is to digital-ly devide the collected geochemical samples into groups bymeans o… 相似文献
342.
343.
通过 1∶5万孟连县、景信幅的区域地质调查 ,在孟连县北西 1∶2 0万孟连幅原划的“西部拉巴组”(原定为下二叠统 )中 ,采获Entactinia -Entactinosphaera组合共 4个属 6个种的放射虫化石 ,结合岩性组合、沉积相等特征 ,重新更正为中—上泥盆统曼信组。为研究该区的地层展布、大地构造环境、古地理、构造活动等提供了新资料。 相似文献
344.
Geologically Constrained Probabilistic Mapping of Gold Potential, Baguio District, Philippines 总被引:1,自引:0,他引:1
Binary predictor patterns of geological features are integrated based on a probabilistic approach known as weights of evidence modeling to predict gold potential. In weights of evidence modeling, the log
e
of the posterior odds of a mineral occurrence in a unit cell is obtained by adding a weight, W
+ or W
– for presence of absence of a binary predictor pattern, to the log
e
of the prior probability. The weights are calculated as log
e
ratios of conditional probabilities. The contrast, C = W
+ – W
–, provides a measure of the spatial association between the occurrences and the binary predictor patterns. Addition of weights of the input binary predictor patterns results in an integrated map of posterior probabilities representing gold potential. Combining the input binary predictor patterns assumes that they are conditionally independent from one another with respect to occurrences. 相似文献
345.
协同GIS软件体系结构研究 总被引:6,自引:0,他引:6
分布式的异构地学信息处理与分析,需有支持协同工作的GIS平台。但是现有的GIS基础平台大都只具有部分协同功能,真正意义上的协同GIS基础平台尚未出现。本文结合计算机支持协同工作的相关理论,提出协同GIS的体系结构,分析了协同逻辑在协同GIS体系结构中各部分的特征和作用,并论述了所涉及的研究内容。 相似文献
346.
The expanse of ocean which makes up all marine areas beyond national jurisdiction has been characterized as the last frontier of exploitation on the planet, a figurative final “Wild West”. Existing users of areas beyond national jurisdiction, with the exception of fisheries, currently have a limited footprint there as a consequence, in part, of substantial hurdles in technological development that need to be overcome before many resources can be extracted at a commercially viable scale. However, we argue surprise shifts perpetuated by both established and emerging users could lead to an expansion in actors taking opportunities to chase lucrative resources that they are currently constrained from exploiting. Rapid development could also lead to a “crowded ocean” due to the multiplication of users which could present a problem given the current lack of a unified institutional framework for governance connecting the different user groups. Here, we have collated trends in human use of areas beyond national jurisdiction and offer a framework for, and examples of, unexpected dynamics relevant to living and non-living marine resources. Such an approach is necessary in order to begin to mobilize an adequate governance response to changing conditions and uses of areas beyond national jurisdiction. This governance response must be able to govern established or potential users, be flexible and adaptive in response to unexpected and unpredictable dynamics and be able to transform in the face of unpredictable future uses of this vast area. Here we present a set of institutional design principles as a first tentative step in this direction. 相似文献
347.
《Marine Policy》2014
Worldwide demand for energy is growing and predicted to increase by up to three times by 2050. Renewable energy will play a vital role in meeting this demand whilst maintaining global climate change targets. Around the British Isles, development of wind farms has entered Round three, with large, high capacity wind parks being planned to enhance energy security and achieve 2020 renewable energy targets. Such developments place additional pressure on existing sea space and may result in conflicts with other marine activities and users. Co-location of certain activities, marine protected areas, aquaculture and commercial fishing in particular, has therefore been proposed as an option to ease demands on space. Using the UK guided by EU and regional policy, as a case study, following the criteria-based planning system, co-location is legally feasible. Crucially, co-location options will depend on site specific characteristics and site management plans. The biology, ecology and hydrology of the site as well as consideration of important commercial and economic factors will be determining factors of success. For marine protected areas compatibility with conservation objectives for the site will be fundamental. Where possible, it is suggested that activities suitable for co-location will develop in tandem with renewable energy projects. The importance of developing joint projects in this manner is particularly true for aquaculture projects to ensure tenure security and commercial viability. Adaptive management will be a basis for evolution of the concept and practice of co-location. Pilot projects and continued monitoring will be essential in shaping the future of co-location of activities. As the Marine Management Organisation continues the development of marine plans for the English inshore and offshore waters, a study into potential solutions for resolving sea use conflicts is timely. This paper therefore provides a concise overview of the current regulation affecting co-location of key marine activities within wind farm zones and provides suggestions on how co-location projects can be adopted and taken forward, using the UK as a case study. 相似文献
348.
《Marine Policy》2014
This study examined the perceptions of fishers from two fishing communities with differing use histories and involvement in the long-standing (16 yr) multiple use Mafia Island marine protected area (MIMP), Tanzania. A randomly distributed questionnaire indicated that 94% of fishers believed that without the MIMP, there would be overfishing, dynamite use, destroyed habitats, and few fish. Fishers were more positive about core zones (no-take fishery closures) than general use zones (areas allowing selective fishing) as a consequence of increases in fishing pressure. Those that reported increased catches and sizes of fish since the creation of the MIMP were more likely to agree with present zone locations and more positive in general about fisheries and conservation planning. Most thought that fish size and gear restrictions were preferable to permanent closures. Perceptions differed among communities and gear users. Community and gear type explained 46% of the variance in responses about the perception that fisheries and conservation are compatible goals. Somewhat surprisingly, these effects were more important than catch increases or involvement in MIMP-related activities. The differences in perception between communities may be partly attributed to different fishing histories. Multiple-use zoning provides a means to identify and resolve conflicts and achieve what are likely universal objectives for fisheries sustainability and conservation. 相似文献
349.
《Marine Policy》2014
The use of self-governance as a fisheries management tool is increasing in New Zealand and elsewhere. Researchers argue that in theory self-governance can lead to improved outcomes, but evaluating actual benefits is difficult because of the need to distinguish self-governance impacts from other influences on fisheries performance. An indicator system was developed in this paper to evaluate the contribution of selfgovernance to the performance of the Bluff Oyster fishery (OYU5), which is also managed under New Zealand's Quota Management System. There is evidence that self-governance makes a positive contribution to economic efficiency, institutional effectiveness and resource preservation in the Bluff Oyster fishery. 相似文献
350.
《Marine Policy》2014
The Galapagos Islands are a prime example of a place where fishery management policies have been established without first understanding the behavior of fishermen. Since the creation of the Galapagos Marine Reserve in 1998, there has not been a single study in the archipelago that investigates fishing behavior and the factors affecting this behavior. This paper addresses this gap in the literature by describing and analyzing the decisions of the fishing fleet for the red spiny lobster fishery. It focuses on factors that affect the short-term decisions regarding both participation and intensity of participation in the lobster fishery. This paper finds that the fishing fleet in the Galapagos Islands behaves as profit maximizing firms, because they consider all the benefits and costs that affect both their participation decision as well as their decision about how frequently to be active after they have decided to participate. The results also show that there is a large latent effort in the lobster fisheries that could threaten the sustainability of any initiatives aimed at increasing catchability, prices, or markets. It is expected that this analysis will be valuable to policy makers when designing or improving the management plans for Galapagos fisheries. 相似文献