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   124665篇
  免费   1908篇
  国内免费   239篇
教育   86791篇
科学研究   13493篇
各国文化   2051篇
体育   9503篇
综合类   175篇
文化理论   1142篇
信息传播   13657篇
  2021年   949篇
  2020年   1703篇
  2019年   2640篇
  2018年   3144篇
  2017年   3442篇
  2016年   3482篇
  2015年   2397篇
  2014年   3280篇
  2013年   27970篇
  2012年   2429篇
  2011年   2769篇
  2010年   2392篇
  2009年   2682篇
  2008年   2470篇
  2007年   2168篇
  2006年   2435篇
  2005年   2409篇
  2004年   3053篇
  2003年   2413篇
  2002年   2211篇
  2001年   2011篇
  2000年   1666篇
  1999年   1566篇
  1998年   1501篇
  1997年   1552篇
  1996年   1741篇
  1995年   1523篇
  1994年   1515篇
  1993年   1504篇
  1992年   1510篇
  1991年   1438篇
  1990年   1428篇
  1989年   1336篇
  1988年   1197篇
  1987年   1126篇
  1986年   1155篇
  1985年   1417篇
  1984年   1289篇
  1983年   1295篇
  1982年   1277篇
  1981年   1196篇
  1980年   1188篇
  1979年   1261篇
  1978年   1228篇
  1977年   1129篇
  1976年   1015篇
  1975年   827篇
  1974年   814篇
  1973年   787篇
  1971年   634篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
952.
953.
954.
Emerging fathers experience a variety of stressors, including identity and role transitions, changes in their relationships, and challenges in developing caregiving skills. Increasing expectations for father involvement in childcare are emphasizing the importance of the father role, but social supports for new fathers remain scarce. Nineteen expectant and new fathers participated in a pilot 5-week group intervention aimed at improving stress coping and involvement attitudes using a combination of mindfulness practices and skill-building for parenting and partner communication. We administered surveys pre- and postintervention to assess efficacy in the areas of stress, depressive symptoms, father involvement attitudes, and mindfulness. Within-participant differences were compared across participants as well as examining individual reliable change. Results indicated initial reductions in stress and depressive symptoms and increases in the mindfulness constructs of nonjudgment and nonreactivity. No significant changes were found in father involvement attitudes. Perinatal intervention specific to fathers holds promise as an underexplored avenue for supporting families across the transition to parenthood.  相似文献   
955.
956.
Abstract

This article discusses the use of R programing language for executing a sentiment analysis of tweets pertaining to library topics. This discussion is situated within the literature of marketing and management sciences, which is employing methods of machine learning and business intelligence to make informed decision-making, and library administration, which has expressed great interest in social media engagement within its literature but has yet to adopt these types of analysis. Presented in this article is a sample code with instructions on how users may execute it within R to retrieve and analyze tweets relevant to library services. Two examples created using the code (analysis of top librarians’ tweets and analysis of posts about major book publishers) are used to demonstrate the functionality of the code. The code presented in this article may be used by libraries to analyze tweets about their library and library-related topics, which, in turn, may inform management and marketing design.  相似文献   
957.
958.
ABSTRACT

The aims of the present study were to provide an in-depth comparison of inter-limb asymmetry and determine how consistently asymmetry favours the same limb during different vertical jump tests. Eighteen elite female under-17 soccer players conducted unilateral squat jumps (SJ), countermovement jumps (CMJ) and drop jumps (DJ) on a portable force platform, with jump height, peak force, concentric impulse and peak power as common metrics across tests. For the magnitude of asymmetry, concentric impulse was significantly greater during the SJ test compared to CMJ (p = 0.019) and DJ (p = 0.003). No other significant differences in magnitude were present. For the direction of asymmetry, Kappa coefficients revealed fair to substantial levels of agreement between the SJ and CMJ (Kappa = 0.35 to 0.61) tests, but only slight to fair levels of agreement between the SJ and DJ (Kappa = ?0.26 to 0.18) and CMJ and DJ (Kappa = ?0.13 to 0.26) tests. These results highlight that the mean asymmetry value may be a poor indicator of true variability of between-limb differences in healthy athletes. The direction of asymmetry may provide a useful monitoring tool for practitioners in healthy athletes, when no obvious between-limb deficit exists.  相似文献   
959.
ABSTRACT

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (< .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.  相似文献   
960.
Ludwig  David 《Science & Education》2019,28(9-10):1263-1265
Science & Education -  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