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   216篇
  免费   17篇
  国内免费   15篇
测绘学   38篇
大气科学   26篇
地球物理   22篇
地质学   90篇
海洋学   22篇
天文学   5篇
综合类   21篇
自然地理   24篇
  2023年   2篇
  2022年   11篇
  2021年   2篇
  2020年   6篇
  2019年   6篇
  2018年   5篇
  2017年   5篇
  2016年   10篇
  2015年   7篇
  2014年   10篇
  2013年   14篇
  2012年   14篇
  2011年   16篇
  2010年   18篇
  2009年   12篇
  2008年   15篇
  2007年   12篇
  2006年   10篇
  2005年   8篇
  2004年   10篇
  2003年   11篇
  2002年   3篇
  2001年   7篇
  2000年   4篇
  1999年   3篇
  1998年   6篇
  1997年   4篇
  1996年   1篇
  1995年   5篇
  1994年   1篇
  1993年   5篇
  1992年   2篇
  1991年   2篇
  1985年   1篇
排序方式: 共有248条查询结果,搜索用时 156 毫秒
81.
简要介绍了Trimble GPS 5700接收机的功能特点及新的RTK增强技术(eRTK),并结合贵阳市1∶2000航空摄影测量工程,介绍了运用Trimble GPS 5700接收机进行的GPS水准拟合高程试验和高程拟合精度,简单阐述了影响GPS高程测量精度的因素及GPS水准拟合高程代替几何水准应注意的几个问题。  相似文献   
82.
Ståle Angen Rye 《Geoforum》2007,38(5):1028-1039
In this paper it is argued that even though communication technologies release distance students considerably from their dependency on a campus, students are still very much connected to places in their daily lives. These connections are constituted through the “placing” of technology, the students’ relations to people in their daily lives and the students’ relations to the education institution. Communication technology not only releases students from the spatial dimensions; it also attaches them to specific places. It is argued that the use of technology in distance education can reduce the students’ flexibility even if they do not have to attend campus regularly. The empirical analysis presented in this paper is based on a case study of a Master’s degree programme in Public Management offered by Open University Indonesia (Universitas Terbuka).  相似文献   
83.
We explore the controversy over nuclear power by looking at the plurality of narratives that have emerged throughout its history. We find a lack of consistency between the visions of nuclear power put forward by governments and industry and the experience associated with economic viability, nuclear accidents, waste handling, and so on. We use the conceptual tool of holon from complexity theory to provide a link between the models used for the governance of nuclear power and the realization of those models. The analysis of the holon over time reveals a systemic inconsistency between the way in which the story about nuclear energy is told and the experience gained after implementing nuclear energy according to the story. This inconsistency is due to the incompatible levels of observation used by different social actors endorsing different perspectives. The implementation of nuclear power has been based on the engineering view, focusing on the functioning of the nuclear power plant considered in abstraction from the wider implications of the adoption of this technology on the environment, on the economy, and on society. We cross-check this narrative with the societal metabolism view in order to provide a long term perspective of the interdependencies between nuclear power and the complex socio-economic system in which it is embedded. We conclude that the controversy over nuclear power may be treated as a problem of contrasting beliefs and normative values in clear disjunction from experience. The analysis presented in this paper suggests that more attention should be given to the quality of the narratives used in policy making.  相似文献   
84.
中国是农业灾害发生频繁且灾情严重的国家之一。农业保险已成为农民灾后恢复生产和灾区重建的重要资金来源,风险保障和经济补偿作用日益凸显。但是,农业保险面临着信息不对称和经营成本高等问题。而利用3S等空间信息技术,可将保险标的空间化,建立承保标的空间数据库,为承保和理赔工作提供空间数据和分析管理支持,实现"按图承保"和"按图理赔",以空间信息技术支持的农业保险创新应用促进了农业保险模式的转变,从而有效地解决农业保险存在的信息不对称和经营成本高等问题,充分发挥农业保险支农惠农的社会管理职能,提升农业保险的风险管理水平,以更好地服务"三农"。  相似文献   
85.
省直管市(县)体制下建设用地监管技术研究   总被引:1,自引:0,他引:1  
面向解决省直体制下市(县)建设用地管理业务监管难度大问题,研究建设用地全过程监管关键技术,设计该模式下的监管模式、技术架构、业务模型和数据模型,实现省直管市(县)模式下的建设用地批前、批中、批后"批-供-用-补-查-登"全过程监管。  相似文献   
86.
通过IMU/DGPS技术在实际测绘生产项目中的应用,研究该技术条件下1∶10 000比例尺地形图测绘外业像控布设方案,试验、分析内业空三加密精度,调整像控方案,最终为IMU/DGPS技术在1∶10 000比例尺地形图测绘中的应用提供相关的技术参考。  相似文献   
87.
In this paper, we compare different policy incentives for overcoming investment uncertainties that are typical for low-carbon technologies prior to their commercialisation, some of which may be attributable to market failures. The paper focuses on the particular case of carbon capture and storage (CCS) technologies and conducts a qualitative multi-criteria analysis of different public policy support schemes for CCS demonstration to evaluate their suitability. The assessed schemes include mandatory CCS, emission performance standards and several different financial incentives (in addition to the European Union Emission Trading Scheme). Based on the available literature and on experience in the UK and Germany with promotion instruments for low-carbon technologies, the results of our analysis suggest that two alternative schemes, a CCS bonus incentive or a carbon dioxide (CO2) price guarantee, perform best in comparison with the other assessed instruments. While they reduce the uncertainty of CCS investments in the face of low European Union Allowance prices, they also avoid significant adverse impacts on operational and investment decisions in electricity markets.  相似文献   
88.
任贵良  杨爱春  YANG Ai-chun 《云南地质》2011,30(2):164-166,163
探采井岩性、产状、岩体破碎程度、构造条件、岩溶发育均利于地下水储存和运移,具有较好的承压条件。水井正好穿越岩溶管道,形成了自喷井(水量1 328m3)。解决2万余人的饮水,缓解旱情,取得了显著社会、经济效益。  相似文献   
89.
Sustainable fisheries are the main objective of Norwegian fisheries management. Despite powerful management tools, sustainability in the fisheries sector is not an easy task. There is no formal definition of the concept, and operationalization is vague. In recent years, private actors and non-governmental organizations (NGOs) have increased their impact on defining sustainability in the fisheries, which has reduced the power of the traditional fisheries management to determine its content. The lack of a clear strategy for fisheries management to increase sustainability makes it timely to address three research questions: (i) what is meant by “sustainable fisheries”, (ii) to what extent has the institutionalization of the Norwegian fisheries management channeled the sustainability concept towards specific trajectories, and (iii) what are the options and hard choices available to increase sustainability in the Norwegian fisheries in the future? These questions are investigated in this article.  相似文献   
90.
2013年,受世界经济复苏乏力、国内经济下行压力加大等不利因素影响,国内非开挖市场在经历了黄金十年后增速明显回落,市场需求萎缩,行业竞争更为激烈,企业之间的分化也进一步加剧。本文回顾了2013年对我国非开挖行业发展具有较大影响的十大重要事件,详细介绍和分析了中关两国非开挖行业的统计情况。  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