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   8704篇
  免费   103篇
  国内免费   8篇
教育   5973篇
科学研究   1111篇
各国文化   52篇
体育   645篇
综合类   3篇
文化理论   57篇
信息传播   974篇
  2022年   49篇
  2021年   103篇
  2020年   140篇
  2019年   200篇
  2018年   316篇
  2017年   298篇
  2016年   291篇
  2015年   174篇
  2014年   279篇
  2013年   1463篇
  2012年   213篇
  2011年   243篇
  2010年   205篇
  2009年   188篇
  2008年   225篇
  2007年   192篇
  2006年   170篇
  2005年   155篇
  2004年   175篇
  2003年   129篇
  2002年   135篇
  2001年   197篇
  2000年   202篇
  1999年   183篇
  1998年   95篇
  1997年   127篇
  1996年   107篇
  1995年   79篇
  1994年   97篇
  1993年   68篇
  1992年   165篇
  1991年   125篇
  1990年   118篇
  1989年   144篇
  1988年   127篇
  1987年   102篇
  1986年   108篇
  1985年   108篇
  1984年   80篇
  1983年   93篇
  1982年   61篇
  1981年   63篇
  1980年   57篇
  1979年   98篇
  1978年   62篇
  1977年   59篇
  1976年   50篇
  1975年   47篇
  1974年   56篇
  1973年   50篇
排序方式: 共有8815条查询结果,搜索用时 62 毫秒
51.
52.
53.
54.
In collaborative problem solving, children produce and evaluate arguments for proposals. We investigated whether 3- and 5-year-olds (N = 192) can produce and evaluate arguments against those arguments (i.e., counter-arguments). In Study 1, each child within a peer dyad was privately given a reason to prefer one over another solution to a task. One child, however, was given further information that would refute the reasoning of their partner. Five-year-olds, but not 3-year-olds, identified and produced valid and relevant counter-arguments. In Study 2, 3-year-olds were given discourse training (discourse that contrasted valid and invalid counter-arguments) and then given the same problem-solving tasks. After training, 3-year-olds could also identify and produce valid and relevant counter-arguments. Thus, participating in discourse about reasons facilitates children’s counter-argumentation.  相似文献   
55.
At the University of Maine, middle and high school teachers observed more than 250 university science, technology, engineering, and mathematics classes and collected information on the nature of instruction, including how clickers were being used. Comparisons of classes taught with (n = 80) and without (n = 184) clickers show that, while instructional behaviors differ, the use of clickers alone does not significantly impact the time instructors spend lecturing. One possible explanation stems from the observation of three distinct modes of clicker use: peer discussion, in which students had the opportunity to talk with one another during clicker questions; individual thinking, in which no peer discussion was observed; and alternative collaboration, in which students had time for discussion, but it was not paired with clicker questions. Investigation of these modes revealed differences in the range of behaviors, the amount of time instructors lecture, and how challenging the clicker questions were to answer. Because instructors can vary their instructional style from one clicker question to the next, we also explored differences in how individual instructors incorporated peer discussion during clicker questions. These findings provide new insights into the range of clicker implementation at a campus-wide level and how such findings can be used to inform targeted professional development for faculty.  相似文献   
56.
57.
To explore the university experiences of students with learning disabilities (LD), 63,802 responses to the 2014 Student Experience in the Research University Survey were analyzed. Compared to other students, those with self‐reported LD (5.96 percent) had difficulty with assignments and had more obstacles caused by nonacademic responsibilities and imposed by their skill levels. Students with self‐reported LD sensed more bias toward people with disabilities on campus, and they were less satisfied with their overall experience. Interactions between disability status and age suggested even more challenges for older students who self‐reported LD. Approximately one‐third of students who self‐reported LD received accommodations. The rate of accommodations was higher among individuals who were wealthy, who lived alone, and who were out‐of‐state students. Compared to students who self‐reported LD but reported no accommodations, those with accommodations had more contact with faculty and less difficulty with assignments.  相似文献   
58.
Cell-cell interactions play a key role in regeneration, differentiation, and basic tissue function taking place under physiological shear forces. However, current solutions to mimic such interactions by micro-patterning cells within microfluidic devices have low resolution, high fabrication complexity, and are limited to one or two cell types. Here, we present a microfluidic platform capable of laminar patterning of any biotin-labeled peptide using streptavidin-based surface chemistry. The design permits the generation of arbitrary cell patterns from heterogeneous mixtures in microfluidic devices. We demonstrate the robust co-patterning of α-CD24, α-ASGPR-1, and α-Tie2 antibodies for rapid isolation and co-patterning of mixtures of hepatocytes and endothelial cells. In addition to one-step isolation and patterning, our design permits step-wise patterning of multiple cell types and empty spaces to create complex cellular geometries in vitro. In conclusion, we developed a microfluidic device that permits the generation of perfusable tissue-like patterns in microfluidic devices by directly injecting complex cell mixtures such as differentiated stem cells or tissue digests with minimal sample preparation.  相似文献   
59.
In the article we solve path planning task for an agent being multirotor unmanned aerial vehicle (multicopter). We propose an approach of estimating path geometry constraints based on UAV flight dynamics model and control constraints. Than we introduce a new path finding method which takes into consideration those geometry constraints and study this method both theoretically and empirically.  相似文献   
60.
This article analyzes the situation surrounding the education of the disabled in Kyrgyzstan. We provide a detailed discussion of the national legal and regulatory framework that guarantees the rights of persons with disabilities to education. We describe the actual situation in the country concerning access to education for this section of the population as well as other factors that impact it.  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