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   261篇
  免费   10篇
  2024年   1篇
  2023年   2篇
  2022年   4篇
  2021年   3篇
  2020年   9篇
  2019年   18篇
  2018年   15篇
  2017年   12篇
  2016年   10篇
  2015年   13篇
  2014年   10篇
  2013年   26篇
  2012年   31篇
  2011年   11篇
  2010年   7篇
  2009年   11篇
  2008年   12篇
  2007年   13篇
  2006年   11篇
  2005年   8篇
  2004年   5篇
  2003年   5篇
  2002年   9篇
  2001年   6篇
  2000年   9篇
  1999年   6篇
  1994年   1篇
  1992年   1篇
  1991年   1篇
  1983年   1篇
排序方式: 共有271条查询结果,搜索用时 78 毫秒
1.
地理学家的演讲与他们运用文字、图象所作的交流同样值得重视.美国的地理学可以通过下述途径得到加强,即围绕地点、地区和全球联系发展实质性演讲,促进自然地理的发展,恢复地理生态的传统.地理信息系统(geographic information systems)对于完成上述任务,对于改进地理学科以满足不断出现的需要,将是一个非常有用的工具.如果我们能够避免自己拆自己的台,避免不现实的空想,避免玩弄语言技巧,而是坚持在大学里进行高质量的教学,并在教师和从事地理实践工作的人员之间开展学术交流,那么地理学将会变得更加有效.我们有一个前所未有的机会来帮助改进美国的中小学地理教育.  相似文献   
2.
信息社会中博物馆的知识传播职能从被动转向主动,博物馆采用信息技术管理藏品和相关数据,不仅要满足传统业务需求,也要面向网络环境中的使用者。在此过程中,文物藏品信息在互联网环境下的呈现,需要采用标准化的描述元数据方案和受控词汇描述文物的核心信息。该研究首先说明文物数据标准的定义与类型,阐述文物描述元数据的概念与作用,并对比CONA、CDWA Lite、Object ID和第一次全国可移动文物普查的描述元数据方案,说明元数据方案差异反映出的设计需求和结果差异;再进一步对比大英博物馆、大都会博物馆、北京故宫博物院、台北故宫博物院线上文物藏品检索方式,通过检视其检索结果的信息结构与内容,阐述合理的描述元数据方案能呈现丰富信息并导向精准检索。最后建议我国文物博物馆领域应完善文物数据标准,文博机构应制定规范化的文物描述元数据方案和配套实施的编目规则与本地受控词表;文博机构官网在线藏品检索系统应考虑用户需求,呈现完善的编目成果。  相似文献   
3.
Monitoring is deemed crucial for the incentivization of a decentralized organization, but its function relies on information transparency between the central authority and the delegated individuals. We test this hypothesis by considering changes in the fiscal behavior of Chinese county governments following an exogenous fiscal reform in 2004/2005 that removed information obstacles between provinces and counties. Employing data on 590 Chinese counties from 2000 to 2009, we find that counties in the reform provinces adopt a more proactive fiscal policy after the reform, suggesting that they become more incentivized in the political competition for economic growth. Such effects are stronger in counties with fewer competing peers and counties with either high or low ranks in the records of economic growth among peers. The increase in counties' productive spending leads to higher economic growth in later years.  相似文献   
4.
The quick and accurate identification of post-earthquake rescue objects can minimize the casualties and property loss caused by earthquakes. With the rapid development of remote sensing technology, rescue objects can be identified through high-resolution remote sensing images. There are two main categories of approaches to identify rescue object through high-resolution images: automatic extraction by a computer and visual judgment by professionals. Although results can be obtained quickly by using automatic extraction, the accuracy of the results is unacceptably low. For visual judgment, the large demands for time and professionals restrict its wide practical application. In this study, we introduce crowdsourcing into the identification of post-earthquake rescue objects. First, we integrate the advantages of the computer and crowdsourcing, which means that the computer takes advantage of the speed of information processing, while crowdsourcing makes full use of human recognition capabilities. Second, we take visual judgment tasks out of the hands of professionals and entrust the tasks to workers in a crowdsourcing platform. Not only are the human resources infinite, but we can also improve the efficiency of identifying rescue objects. Third, we propose a crowdsourcing model that improves the quality of the results and saves human resources. Finally, experimental results demonstrate that our solution is feasible.  相似文献   
5.
关于利用历史文献信息进行环境演变研究的几点看法   总被引:1,自引:0,他引:1  
针对如何更好地利用我国丰富的历史文献记录,开展历史时期环境演变研究,本文提出四点看法:从地球系统科学与全球变化研究的前沿中寻找研究的主题,在诸多不确定中寻找确定性答案,构建历史文献信息共享的环境演变研究平台,培养文理兼备的复合型人才。  相似文献   
6.
The arrival of the term Geographical Information System (GIS) in the 1960s soon created a demand for training and education in the use of this specialist hardware and software. Initially the main focus was on training people to use GIS, formal named degree programmes leading to postgraduate and undergraduate qualifications arrived later. This paper explores the changing landscape of U.K. degree level GIS education drawing on contemporary information from Higher Education Institution websites and a case study of the first single honours degree in GIS in Europe. The paper identifies a rise and fall in the number of named undergraduate “GIS” degrees since the late 1980s sandwiched between the continuation and development of postgraduate qualifications. In parallel with this trend the teaching and learning of GIS skills has emerged as a core component of undergraduate degree programmes with “Geography” in their title and in national school and degree level benchmarking statements for the discipline.  相似文献   
7.
Active learning is increasingly promoted within institutions of higher education to assist students develop higher order thinking and link knowledge to meaning. In this paper, the authors evaluate the use of weekly online quizzes based on prescribed preparatory material as a tool to incentivize preparatory reading in order to enable and encourage active learning. The study is based on mixed data sources, including three years of student-evaluation data, to understand student perceptions of the role and value of online quizzes. The study shows a high level of student engagement with the quizzes and positive assessment of their role in encouraging the completion of prescribed reading. Online quizzes were found to be an effective mechanism for incentivizing student completion of preparatory work, enhancing active learning (such as through in-class discussions), and were relatively time efficient from the perspective of the educator.  相似文献   
8.
In Israel and Palestine, map-making practices were always entangled with contradictive spatial identities and imbalanced power resources. Although an Israeli narrative has largely dominated the ‘cartographic battlefield’, the latest chapter of this story has not been written yet: collaborative forms of web 2.0 cartographies have restructured power relations in mapping practices and challenged traditional monopolies on map and spatial data production. Thus, we can expect web 2.0 cartographies to be a ‘game changer’ for cartography in Palestine and Israel. In this paper, I review this assumption with the popular example of OpenStreetMap (OSM). Following a mixed methods approach, I comparatively analyze the genesis of OSM in Israel and Palestine. Although nationalist motives do not play a significant role on either side, it turns out that the project is dominated by Israeli and international mappers, whereas Palestinians have hardly contributed to OSM. As a result, social fragmentations and imbalances between Israel and Palestine are largely reproduced through OSM data. Discussing the low involvement of Palestinians, I argue that OSM's ground truth paradigm might be a watershed for participation. Presumably, the project's data are less meaningful in some local contexts than in others. Moreover, the seemingly apolitical approach to map only ‘facts on the ground’ reaffirms present spatio-social order and thus the power relations behind it. Within a Palestinian narrative, however, many aspects of the factual material space might appear not as neutral physical objects but as results of suppression, in which case, any ‘accurate’ spatial representation, such as OSM, becomes objectionable.  相似文献   
9.
Many questions remain about the effects of digital media use on citizens’ political engagement. This article argues that this is because such effects depend on the context in which digital media are used. Its findings are based on two cross-sectional sets from the 2010 and 2013 Australian Election Study and show that (1) political resources played different moderating roles in the association between digital media and offline participation, and (2) such a moderating role depended on different campaign contexts in the two elections, with context affecting political efficacy. The findings confirm that campaign context can function as leverage in motivating online news consumption and political participation, thereby emphasising the importance of political contexts in media use and political behaviour.  相似文献   
10.
GIS技术在萨拉乌苏考古遗址公园规划设计中的应用   总被引:1,自引:0,他引:1  
传统规划设计工作的技术平台多以计算机辅助设计(CAD)为主,本工作以内蒙古自治区鄂尔多斯萨拉乌苏考古遗址公园规划为例,将Arc GIS Desktop作为技术平台应用到公园的规划设计工作中。首先,通过对规划区的实地踏勘,采集相关数据和资料,进行规划区数据库建设;其次,在数据库建设的基础上,通过GIS技术构建与现实环境对应的虚拟地理信息空间,实现规划区景观的三维可视化;最后,利用三维景观模型对现实地理环境进行模拟、分析及虚拟场景飞行。不同于传统CAD的二维工作平台,本工作借助GIS对空间数据和属性数据的强大处理功能及其三维景观可视化模块,为实现内蒙古鄂尔多斯萨拉乌苏考古遗址公园的科学规划提供辅助。  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