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   1673篇
  免费   39篇
  国内免费   3篇
教育   1168篇
科学研究   76篇
各国文化   19篇
体育   158篇
综合类   1篇
文化理论   18篇
信息传播   275篇
  2023年   7篇
  2022年   9篇
  2021年   17篇
  2020年   38篇
  2019年   57篇
  2018年   74篇
  2017年   89篇
  2016年   74篇
  2015年   53篇
  2014年   60篇
  2013年   389篇
  2012年   42篇
  2011年   50篇
  2010年   36篇
  2009年   46篇
  2008年   50篇
  2007年   39篇
  2006年   46篇
  2005年   44篇
  2004年   40篇
  2003年   39篇
  2002年   25篇
  2001年   21篇
  2000年   28篇
  1999年   19篇
  1998年   17篇
  1997年   10篇
  1996年   16篇
  1995年   11篇
  1994年   11篇
  1993年   19篇
  1992年   15篇
  1991年   12篇
  1990年   16篇
  1989年   12篇
  1988年   21篇
  1987年   6篇
  1986年   10篇
  1985年   12篇
  1984年   9篇
  1983年   8篇
  1982年   7篇
  1980年   6篇
  1977年   8篇
  1973年   10篇
  1971年   5篇
  1970年   7篇
  1968年   8篇
  1967年   5篇
  1966年   5篇
排序方式: 共有1715条查询结果,搜索用时 15 毫秒
91.
Imagine the challenge of being immersed in a dynamic learning network where you play brinkmanship with being overwhelmed by a plethora of information, comments, and conversations on a topic of intense interest to you. Through adept facilitation, the comments and encouragement of fellow participants, and your own perseverance, you develop a network of personal connections which serve as metaphorical flying buttresses creating enough stability that you are able to learn in a new, yet profoundly meaningful way – the connectivist massive open online course (cMOOC) way. Through the lens of autoethnography, five seasoned educators collaboratively reflect on their motivation for participating in their initial cMOOC. They analyze their lived experience, what they found most engaging, and most importantly, they grapple with why cMOOC communities often endure past official end-dates. This article attempts to provide insight into the thrill and depth of learning and connection possible through participation in cMOOCs.  相似文献   
92.
93.
In recent years, there has been a strong push to transform STEM education at K-12 and collegiate levels to help students learn to think like scientists. One aspect of this transformation involves redesigning instruction and curricula around fundamental scientific ideas that serve as conceptual scaffolds students can use to build cohesive knowledge structures. In this study, we investigated how students use mass balance reasoning as a conceptual scaffold to gain a deeper understanding of how matter moves through biological systems. Our aim was to lay the groundwork for a mass balance learning progression in physiology. We drew on a general models framework from biology and a covariational reasoning framework from math education to interpret students' mass balance ideas. We used a constant comparative method to identify students' reasoning patterns from 73 interviews conducted with undergraduate biology students. We helped validate the reasoning patterns identified with >8000 written responses collected from students at multiple institutions. From our analyses, we identified two related progress variables that describe key elements of students' performances: the first describes how students identify and use matter flows in biology phenomena; the second characterizes how students use net rate-of-change to predict how matter accumulates in, or disperses from, a compartment. We also present a case study of how we used our emerging mass balance learning progression to inform instructional practices to support students' mass balance reasoning. Our progress variables describe one way students engage in three dimensional learning by showing how student performances associated with the practice of mathematical thinking reveal their understanding of the core concept of matter flows as governed by the crosscutting concept of matter conservation. Though our work is situated in physiology, it extends previous work in climate change education and is applicable to other scientific fields, such as physics, engineering, and geochemistry.  相似文献   
94.
This article examines how we use mobile telephony to maintain our physically and socially closest social circle. The analysis is based on traffic data gathered from Norway using approximately 24 million calls and texts made by private individuals. Previous research has shown that our temporal and spatial movement is highly predictable and that the majority of calls and text messages are sent to only four to six different persons. This article extends this research by examining both tie strength and the distance between the interlocutors in urban and rural settings. The findings show that even as information and communication technologies (ICTs) potentially put the world at our fingertips, the mobile phone is an instrument of a more limited geographical and social sphere. Approximately two-thirds of our calls/texts go to strong ties that are within a 25-km radius.  相似文献   
95.
This paper advances the ongoing discussion of methods for predicting movie box office revenues with two contributions to the methodology and an out-of-sample test of the model. The first innovation is the development of a two-stage model using publicly available pre-release indicators to predict (1) initial week and (2) subsequent run box office revenues. To incorporate the experience-good nature of movies, the second stage is estimated by incorporating a proxy variable for box office success during the first week relative to predicted first week success. The second contribution is an empirical test of De Vany and Walls’ (J Econ Dyn Control 28:1035–1057, 2004) finding that the distribution of movie revenues has “heavy tails” and follows a non-Gaussian stable distribution with infinite variance. We estimate the two-stage model of a movie’s box office success on all general release movies in 1 year with both the Gaussian and stable distribution with heavy tails and infinite variance and find no evidence for the stable distribution in either stage of the estimation. This two-stage model is validated by comparing all general release movies in 3 future years (out-of-sample data) to the model’s predictions.  相似文献   
96.
97.
98.
99.
100.
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