全文获取类型
收费全文 | 815篇 |
免费 | 7篇 |
国内免费 | 20篇 |
专业分类
教育 | 637篇 |
科学研究 | 115篇 |
体育 | 4篇 |
综合类 | 68篇 |
信息传播 | 18篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 16篇 |
2019年 | 11篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 21篇 |
2014年 | 41篇 |
2013年 | 58篇 |
2012年 | 81篇 |
2011年 | 75篇 |
2010年 | 37篇 |
2009年 | 58篇 |
2008年 | 56篇 |
2007年 | 69篇 |
2006年 | 60篇 |
2005年 | 51篇 |
2004年 | 42篇 |
2003年 | 26篇 |
2002年 | 24篇 |
2001年 | 27篇 |
2000年 | 14篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有842条查询结果,搜索用时 15 毫秒
61.
62.
文章通过Kalman滤波器预测由Camshift算法检测到的人脸窗1:7在下一帧图像可能出现的位置,进行下一帧图像的人脸跟踪.其中,Kalman滤波器的使用克服了单纯使用Cam-shift跟踪在遮挡或者丢失跟踪物体的不足,可以大大提高人脸跟踪的正确率. 相似文献
63.
Just as linguistic errors have provided insights into the nature of linguistic competence(s), detailed analyses of blind spots or marked trajectories in the reflection cycles of novice teachers may provide a window on their underlying beliefs, and thus on relevant zones of proximal development. In this paper we analyse a case study in an experimental web‐based learning environment in which a novice teacher demonstrably just reproduces the assumptions she started out with rather than re‐inspecting them. Having located a problem of motivation uniquely inside the learners’ heads, she pointedly ignores hints in the feedback that her own verbal and nonverbal behaviour in the classroom might be a relevant domain of enquiry. Our findings show the need for structural interventions within a priori hypothesized, linearly ordered, stages in reflection models. We report on two small‐scale experiments that implement suggested changes in the architecture of the web site which yield more context‐sensitive ways of scaffolding reflection. In conclusion we argue that detailed discursive accounts of successful and less successful reflection trajectories are needed to refine and further develop models in teacher thinking. 相似文献
64.
针对传统蒙特卡罗法分析耦合谐振腔滤波器灵敏度耗时太长的问题,提出了一种基于理论梯度公式的快速灵敏度分析方法.文章详细推导了滤波器散射参数对终端阻抗和耦合系数的灵敏度解析表达式,并采用MATLAB编程实现了基于灵敏度表达式的数值算法.应用该算法对5阶交叉耦合谐振腔滤波器的灵敏度进行了分析,灵敏度分析结果对耦合谐振腔滤波器的设计和加工具有参考价值. 相似文献
65.
66.
67.
ABSTRACTThis study examines the patterns of news engagement among news consumers with different political affiliation and cultural background. We use computational methods and data from Twitter in a cross-country comparison of engagement with six online news sources in Australia and South Korea. For our analysis, we used a subset of Twitter users who retweeted at least one political story during the period of collection, and for whom we were able to predict political affiliation using correspondence analysis and data on Twitter follower ties to politicians. We find that right-wing Australian retweeters are more intense in their news engagement, compared with their left-wing counterparts, whereas in South Korea it was the opposite. Australian right-wing political retweeters have more diverse information sources, while there was no difference in information diversity between the right and left in South Korea. We discuss how the political situation in South Korea at the time of data collection may have affected our analysis. We emphasise the methodological contributions of our research and its connection to on-going research into the behavioural foundations of ‘filter bubbles’. 相似文献
68.
卡尔曼滤波方法原理清晰,易实现计算机自动化,自行编制的卡尔曼滤波法计算机程序,计算速度快、精度高,其结果与文献值非常接近,实现了多组分的同时测定。 相似文献
69.
基于多相滤波的正交处理器技术是软件无线电技术的重要组成部分。本文对基于多相滤波的正交处理器进行了详细的研究,并给出了在MATLAB环境下的仿真结果。 相似文献
70.
光散射法粒度测试涉及到粒度反演技术.随着反演粒级数的增加,通常的粒度反演法将出现严重的振荡.文章将Chahine迭代算法与平滑滤波技术相结合解决了高反演粒级数下数值解的振荡,在不改变激光粒度仪的原有结构情况下,就可明显提高仪器的精度和分辨能力. 相似文献