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   1489篇
  免费   26篇
  国内免费   38篇
教育   751篇
科学研究   623篇
各国文化   1篇
体育   40篇
综合类   42篇
文化理论   5篇
信息传播   91篇
  2024年   1篇
  2023年   135篇
  2022年   153篇
  2021年   164篇
  2020年   141篇
  2019年   154篇
  2018年   22篇
  2017年   15篇
  2016年   13篇
  2015年   17篇
  2014年   52篇
  2013年   65篇
  2012年   104篇
  2011年   103篇
  2010年   49篇
  2009年   72篇
  2008年   38篇
  2007年   49篇
  2006年   38篇
  2005年   34篇
  2004年   13篇
  2003年   14篇
  2002年   20篇
  2001年   29篇
  2000年   35篇
  1999年   14篇
  1998年   6篇
  1997年   3篇
排序方式: 共有1553条查询结果,搜索用时 15 毫秒
1.
The tacit nature of knowledge suggests that face-to-face interactions in international academic collaborations are irreplaceable. Yet, such anecdotal evidence has not been adequately examined in the extant literature. Using the difference-in-differences estimation strategy, this paper investigates the causal effect of international nonstop flights on the quantity of high-impact Sino-US joint publications over the period between January 2009 and December 2018. We find that, on average, US-China international nonstop flights boost the production of influential articles aggregated at Chinese cities, with cities with less human capital earning more benefits. We do not find evidence in support of the crowding-out effect indicating this positive effect comes at the expense of domestic and international collaboration opportunities with other countries. These findings remain robust with various specifications. Policy implications for promoting global collaboration through face-to-face communication are discussed in the end.  相似文献   
2.
双目相机虽然能通过算法生成密集的深度数据,但其在精度上与激光雷达生成的深度数据有着较大的差距,特别是在纹理不明显的区域。针对这种现象,尝试使用激光雷达的精确点云来排除由双目相机产生的pseudo-LiDAR数据中与之差别较大的部分点,然后将优化后的pseudo-LiDAR用以进行三维物体检测。实验结果显示,将pseudo-LiDAR数据中的不准确点(坏点)排除,有助于提高检测准确率,最多可提高21.02%。因此,如何不依赖激光雷达数据来排除pseudo-LiDAR点云中的坏点是进一步提高双目相机系统检测准确率的关键。  相似文献   
3.
信息网格技术的研究和实现   总被引:3,自引:0,他引:3  
信息网格是网格技术的重要应用模式,本文在分析网格技术的基础上介绍了信息网格的应用背景、定义,讨论了信息网格的关键技术,并详细介绍了信息网格的典型事例——上海网格。  相似文献   
4.
5.
刘斌  曹民 《教育技术导刊》2019,18(10):23-26
汽轮发电机组逐渐智能化,功能不断增强,但不确定性因素和不确定性信息仍然大量存在。针对该问题,用概率神经网络(PNN)诊断汽轮发电机组故障。PNN优点较多,机器学习算法简易、方便训练,相比于传统样本处理方法,PNN可训练样本并引入训练网络,更好地确保诊断结果正确率与可信度。MATLAB仿真结果表明,PNN在保证诊断结果准确的基础上,速度更快、分类性能大幅提高,诊断效率也提高至98%。  相似文献   
6.
Automatic Chinese text summarization for dialogue style is a relatively new research area. In this paper, Latent Semantic Analysis (LSA) is first used to extract semantic knowledge from a given document, all question paragraphs are identified, an automatic text segmentation approach analogous to Text'filing is exploited to improve the precision of correlating question paragraphs and answer paragraphs, and finally some "important" sentences are extracted from the generic content and the question-answer pairs to generate a complete summary. Experimental results showed that our approach is highly efficient and improves significantly the coherence of the summary while not compromising informativeness.  相似文献   
7.
1 Introduction Organiclight emittingdiodes(OLEDs)haveattract edconsiderableattentionduetoitsgreatpotentialinefficiency ,low voltage ,large area ,lightweight ,andfull colorflat paneldisplays[1,2 ] .Forfull colordis plays ,itisnecessarytohaveefficientred ,green ,andblueemitterswithappropriatechromaticity .Bycom parisonwiththehighperformanceofblueandgreenOLEDs ,theperformanceandpurechromaticityofredOLEDsarestillrelativelypoor .UsuallyredOLEDsareimprovedbydopingreddyesintohostmaterialswit…  相似文献   
8.
The idea of discovering patterns in data seems to be essential for decision making in our social activities. This paper presents a simple algorithm which can be used to detect such patterns in elementary sequences of symbols. It adopts a data compression algorithm to seek for interesting patterns, which is important in understanding the way that the input symbol stream repeats itself. In this paper, the algorithm and related data structures are described in detail, and an illustrative example is given.  相似文献   
9.
1 Introduction SMP (symmetricmulti processing)andMPP (mas sivelyparallelprocessing)arethetwotypesofstruc tureofparallelcomputing . Symmetricmulti processingsystemshavemultipleCPUsattachedtothesamebusandsharingRAM .Massivelyparallelprocessingisthecooperated pro cessingofaprogrambymultipleprocessorsthatworkondifferentpartsoftheprogram ,witheachprocessorusingitsownoperatingsystemandmemory .ThechoicebetweenSMPandMPPdependsonthenatureoftheproblembeingsolved .Iftheproblemcanbeeasilypartit…  相似文献   
10.
李欣 《海外英语》2011,(14):137-139
An L2 learner’s pragmatic competence is an inseparable part of his communicative competence.Large quantities of aspects of pragmatic competence are teachable.Classroom is the place where an L2 learner’s pragmatic competence can be developed.Though classroom instruction has some negative effect,efforts could be done to arrange relevant awareness-raising and communication-practice activities.  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