首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   565篇
  免费   41篇
  国内免费   15篇
测绘学   107篇
大气科学   28篇
地球物理   99篇
地质学   111篇
海洋学   139篇
天文学   5篇
综合类   43篇
自然地理   89篇
  2024年   2篇
  2023年   2篇
  2022年   3篇
  2021年   5篇
  2020年   6篇
  2019年   7篇
  2018年   2篇
  2017年   28篇
  2016年   17篇
  2015年   18篇
  2014年   38篇
  2013年   27篇
  2012年   27篇
  2011年   36篇
  2010年   37篇
  2009年   40篇
  2008年   41篇
  2007年   40篇
  2006年   30篇
  2005年   29篇
  2004年   19篇
  2003年   24篇
  2002年   26篇
  2001年   18篇
  2000年   18篇
  1999年   11篇
  1998年   13篇
  1997年   9篇
  1996年   6篇
  1995年   4篇
  1994年   4篇
  1993年   8篇
  1992年   10篇
  1991年   4篇
  1990年   3篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1982年   2篇
排序方式: 共有621条查询结果,搜索用时 15 毫秒
611.
分析了两年制研究生教育新模式的意义,论述了测绘工程两年制硕士研究生培养所采取的措施,探讨了测绘工程专业两年制研究生培养的途径。  相似文献   
612.
建立国土资源科技信息与外事管理信息系统是实现国土资源科技发展与创新的重要平台,本文从关键技术、系统结构、系统功能等方面探讨了在ASP.NET的环境下,采用B/S模式,构建三层架构的国土资源科技信息与外事管理信息系统的方法,最后利用设计的思路,实现了国土资源科技与信息数据库的建立和系统的开发工作。  相似文献   
613.
基于C/S与B/S混合体系结构的林业管护经营监控系统的设计   总被引:1,自引:0,他引:1  
对C/S,B/S两种软件体系结构进行了分析比较,论述了林业管护经营监控系统是一个大型的、复杂的监控系统,针对不同的用户,采取合理的软件体系结构设计,将会使该系统具有更好的应用前景.提出了基于C/S与B/S混合体系的林业管护经营监控系统的设计框架,包括其实现的主要功能、体系结构、安全策略、数据备份与恢复等关键技术.  相似文献   
614.
In offshore waters of the German North Sea multiple stakeholder activity is increasing in both type and intensity. Newcomers such as wind farms make for additional claims and exclude, due to current legal constraints, other sectors, such as traditional fisheries. In this context, integrating marine aquaculture with designated wind farm areas might provide chances to combine two industries in the frame of a multiple-use concept. This paper takes up concerns and possible management framework requirements as expressed through interviews with the wind farm industry and the mussel harvesting sector when inquiring about such a multiple-use setting. The article closes with a discussion on two co-management strategies that might be appropriate for governing potential interacting wind farm–mariculture activities.  相似文献   
615.
Mixed messages: Buying back Australia's fishing industry   总被引:1,自引:1,他引:0  
This paper discusses the process and outcomes of a major buyback of commercial fishing concessions across all Australian Commonwealth-managed fisheries through 2006. It argues that the intent of the buyback program was ambiguous, the process was flawed, and the outcomes of doubtful benefit to fish or to fishermen. This case study directs attention to deeper issues that prevail in forms of managing people under the guise of a non-explicit ideology of “extol and control”.  相似文献   
616.
The practical implementation of an ecosystem approach to fisheries (EAF) management has proved difficult to achieve. Without simple and structured guidelines for implementing an EAF, managers are grappling with the complexity of implementation and the need to prioritise resources and management actions. Ecological risk assessment has been put forward as a structured procedure. There is a need to review regularly whether progress is being made in addressing the issues and priorities identified through ecological risk assessment. Such reviews require a framework providing clear objectives for the respective fishery and delineating the steps required towards their achievement. This paper proposes a generic framework for reviewing ecological risk assessments through stakeholder workshops. This framework is aided by a fuzzy logic tool to track EAF implementation and informs the development of proactive work plans which incorporate EAF objectives. The advantages and disadvantages of a generic and participatory approach are discussed and compared with other related methods for evaluating progress in implementing an EAF.  相似文献   
617.
Public participation is a key ingredient of good governance and there are many advantages of involving stakeholders in the decision-making process. The European Commission identified the lack of stakeholder involvement as one of the major weaknesses of the Common Fisheries Policy (CFP). As such, the 2002 Reform of the CFP aimed to improve its system of governance by increasing the involvement of stakeholders in decision-making. Over the last decade, Scottish inshore waters have seen an increase in management measures focused on involving fishers, delegating responsibilities and decentralizing management. The present document investigates commercial inshore fishers’ perceptions of participation in the decision-making process and attitudes towards a new management regime – the Inshore Fisheries Groups (IFGs) – which aims to increase participation in and decentralization of inshore fisheries management. A survey was conducted, through face-to-face interviews, and ordered logistic and multiple regression models created to identify which characteristics influence fishers’ perceptions and attitudes. The present analysis concluded that, 5 years subsequent to the reform of the CFP, the majority of inshore fishers perceive themselves not to be consulted or involved in the decision-making process. However, and despite the fact that fishers are not completely certain of the potential of the IFGs to increase their participation in the management process, they have an overall positive attitude towards their implementation.  相似文献   
618.
The value of applying a regional level, Ecosystem Based Fisheries Management (EBFM) framework, which is a step-wise, hierarchical, risk-based approach, was tested on the West Coast Bioregion of Western Australia. With structured stakeholder input, over 600 ecological, social, economic and governance issues were initially identified for the region. This complexity was reduced to a level useful for management by consolidating the individual risks into 60 regional-level risks, with a multi-criteria analysis used to integrate the ecological, social and economic risks into just 24 Departmental-level priorities, which ranged from very low to urgent. Given this success, EBFM-based priorities now form the basis for the Department’s budget planning process, plus the framework is providing a critical link between fishery level issues and the broader processes undertaken by other marine based agencies. The EBFM framework is a significant step forward for the integrated management of natural resources by enabling all assets and issues relevant to stakeholders and government to be holistically considered at a regional level.  相似文献   
619.
区域管理信息系统是为区域规划、管理和决策服务的。经调查研究和系统设计,系统的数据分类体系一般需要7—8级分类才能把有关专题图上最小图斑的内容或属性表示出来。7—8级分类体系中最高的3级分类为高位分类,是各级区域管理信息系统中必须具有的分类。低位分类是第3级高位分类的细化,具有更强的学科性。由于它涉及的学科繁多,各专题分类形式各异。最后决定用32位数字组成区域管理信息系统的数据分类编码,其含有高位分类码、低位分类码、区位码、时间码、顺序码和机动码,分别占用4、8、6、6、4和4位码。便于各级区域管理信息系统之间的数据共享和交换。  相似文献   
620.
姚文江 《江苏地质》2003,27(2):94-96
结合江苏省地质调查研究院的数字成果数据情况,讨论了数字成果数据管理的方法技术实现问题。采用:MSSQL Server。作为数字成果数据的数据库管理系统;采用VB开发工具,结合GIS技术开发客户端软件,即利用VB提供的ADO Field对象的GetChunk和AppendChunk方法来存取MS SQL Server中的图形数据,并通过GIS技术对图件进行管理和再现。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号