全文获取类型
收费全文 | 115篇 |
免费 | 14篇 |
国内免费 | 4篇 |
专业分类
测绘学 | 3篇 |
大气科学 | 2篇 |
地球物理 | 32篇 |
地质学 | 54篇 |
海洋学 | 29篇 |
综合类 | 6篇 |
自然地理 | 7篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 7篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2011年 | 10篇 |
2010年 | 4篇 |
2009年 | 15篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 6篇 |
排序方式: 共有133条查询结果,搜索用时 522 毫秒
121.
Andalusia is a region of Spain with an area of some 90,000 km2 and almost 900 km length of coastline. It has an important tradition in the fishing industry that makes it one of the areas of the European Union where fisheries policies have a great significance for the population. The present statistical study deals comprehensively with the so-called “artisanal fleet”, especially in respect of data on the typology of vessels (construction particulars) and on the extractive effort made (distances and depths where they fish, duration of fishing voyages, the fishing gear used and target species), with the aim of presenting a new approach in the policies for regulating this important fisheries sector. 相似文献
122.
123.
124.
125.
湿地水环境安全及其评价指标体系研究 总被引:1,自引:0,他引:1
在提出湿地水环境安全内涵的基础上,构建了湿地水环境安全评价指标体系,重点建立了河流型湿地、湖泊型湿地和库塘型湿地水环境安全评价指标体系。 相似文献
126.
127.
Günther Fischer Tatiana Ermolieva Yuri Ermoliev Laixiang Sun 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(4):441-450
In this paper we show that explicit treatment of risks and uncertainties in agricultural production planning may considerably
alter strategies for achieving robust outcomes with regard to sustainable agricultural developments. We discuss production
planning models under uncertainties and risks that may assist in planning location-specific production expansion within environmental
and health risk indicators and constraints. The proposed approaches are illustrated with the example of spatially explicit
livestock production allocation in China to 2030. 相似文献
128.
大中型企业网络的安全形势越来越严峻,在分析企业网络安全的基础上,从防病毒技术、防火墙技术、入侵检测技术及主机防护等方面阐述了网络安全防护技术,基于安全平台的构建与应用,给出了配套的软件及解决方案。 相似文献
129.
近年来,随着发展"绿色航运经济"的话题热度不断升温,北极西北航道因其潜在的巨大通航价值成为各国诉争的焦点,与此同时,船舶通行所带来的对海洋生态的侵蚀破坏,例如燃油废料和塑料垃圾等,引发了国际法视域内的诸多争议。以加拿大为代表的西北航道沿岸国滥用国际海洋法框架下关于航行自由和环境保护的模糊地带,肆意扩张国内法的管制范围对他国的航行自由进行不合理限制的问题愈加凸显。为了国际航海秩序的和平稳定,实现北极航运的可持续发展,文章以北极西北航道沿岸国借助"环境保护"名义限制他国在西北航道航行自由权的法律援引模式为切入,对航行安全控制区制度和特别敏感海域制度的法律争议进行分析,综合体系解释的方法和国际法实践判例的指引,构建北极西北航道航行自由与环境保护的平衡路径。 相似文献
130.
Design and Implementation of the Hydrographic Production and Management Information System (HYPAMIS)
With the development of hydrographic work and information techniques, the traditional work mode is not suitable for the Chinese Marine Safety Administration Bureau (CMSAB). Aiming at the separation of charts production and management, a new idea that is the integration of production, management, and quality control is presented. Geographic Information System (GIS), Management Information System (MIS), Office Automation (OA) and Spatial Database Management (SDM) advanced techniques are introduced into the workflows in CMSAB. To realize information sharing, a mixed mode with Browser/Server (B/S) mode and Client/Serve (C/S) mode are adopted. Based on the above ideas and strategies, an integrated system named Hydrographic Production And Management Information System (HYPAMIS) was developed. The whole workflow and three subworkflows including survey management workflow, production workflow, and quality control workflow of are outlined after re-engineering the CMSAB organization. Some design principles and key techniques of the HYPAMIS including the cooperation of GIS and MIS, object-oriented spatial data model and management, data management based on database, and security control are illustrated in detail. Then the implementation of the system is introduced briefly. Finally, performance evaluation of the system and future work is given. 相似文献