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   123285篇
  免费   1893篇
  国内免费   243篇
教育   85026篇
科学研究   13589篇
各国文化   1989篇
体育   9950篇
综合类   195篇
文化理论   1082篇
信息传播   13590篇
  2021年   960篇
  2020年   1682篇
  2019年   2612篇
  2018年   3227篇
  2017年   3493篇
  2016年   3508篇
  2015年   2334篇
  2014年   3198篇
  2013年   27312篇
  2012年   2498篇
  2011年   2958篇
  2010年   2428篇
  2009年   2645篇
  2008年   2518篇
  2007年   2299篇
  2006年   2478篇
  2005年   2487篇
  2004年   3143篇
  2003年   2445篇
  2002年   2274篇
  2001年   2172篇
  2000年   1840篇
  1999年   1721篇
  1998年   1477篇
  1997年   1539篇
  1996年   1709篇
  1995年   1467篇
  1994年   1477篇
  1993年   1474篇
  1992年   1576篇
  1991年   1388篇
  1990年   1395篇
  1989年   1305篇
  1988年   1139篇
  1987年   1083篇
  1986年   1114篇
  1985年   1335篇
  1984年   1213篇
  1983年   1153篇
  1982年   1108篇
  1981年   1026篇
  1980年   977篇
  1979年   1171篇
  1978年   1081篇
  1977年   978篇
  1976年   898篇
  1975年   743篇
  1974年   740篇
  1973年   710篇
  1972年   565篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
This article focuses on counseling research in the community college context. The article suggests the need for a robust community college knowledge base, describes some limitations of the current community college literature, and suggests a framework for more effective work in this area. The authors’ own experiences and selected examples of published studies are used as illustrations of the hurdles encountered and solutions available when examining counseling theories, practices, and outcomes in 2‐year settings.  相似文献   
994.
This paper demonstrates the application of module arithmetic for controlling the level of information security by a new technique referred as integer splitting. The basic definitions and concepts of the method are provided. The mathematical function of arising transformation is described in detail; its properties were studied and the basic theorems were proven that justify the use of splitting in practical applications. An active system was designed and characteristic cases of its operation are considered.  相似文献   
995.
996.
997.
998.
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   
999.
Considering the growth in research, examining the development of mainstream sport athletes over the past two decades, studies examining development of athletes with disabilities have been surprisingly limited. While similarities in developmental trajectories between the two cohorts may exist regarding factors such as the value of practice, which tend to be universal regardless of context, disability-related issues (e.g. whether the disability was congenital or acquired) may influence the course of development, affecting variables such as starting age, training and developmental milestones. Fifty-two male and female athletes training with the Wheelchair Basketball Canada National Academy provided detailed training histories. Athletes illustrated similar developmental patterns (e.g. milestones, training adjustments) as they progressed through their sporting career. However, athletes with congenital disabilities started participation in wheelchair basketball and unorganised practice at significantly younger ages (t49?=??4.35, p?<?.001, d =?1.32; t49?=??3.49, p?<?.001, d =?1.03, respectively). While athletes with congenital disabilities continued to reach a majority of the sporting milestones at younger ages, athletes with acquired disabilities were able to reach late career milestones (e.g. national debuts) at similar ages. Athletes’ disability severity did not influence their progress through the developmental milestones and time devoted to training throughout their sporting career. Future work may consider examining developmental trajectories and training histories of athletes in various parasports to extend our understanding of their development and skill acquisition.  相似文献   
1000.
Purpose: The benefits of physical activity (PA) in preventing abdominal obesity are well recognized, but the role of different sport disciplines remains open. We aimed, therefore, to investigate how participation in different sport disciplines, and the number and types of sports engaged in are associated with waist circumference (WC) in young adulthood. Methods: This population-based cohort study comprised 4027 Finnish twin individuals (1874 men), with a mean age of 34 y (32–37), who answered a survey, including self-measured WC. We extracted the number and identified the types (aerobic, power, and mixed) of the different sport disciplines respondents reported participating in. Results: The number of sport disciplines participated in was inversely associated with WC, the linear decrease averaging 1.38?cm (95% CI 1.10–1.65) per each additional sport discipline. The result persisted after adjustment for the main covariates, such as volume of PA and diet quality. Among dizygotic twin pairs discordant for sports participation (0–2 vs. 5 or more disciplines), the mean within-pair difference in WC was 4.8?cm (95% CI 0.4–9.1) for men and 11.2?cm (95% CI 4.4–18.0) for women; among discordant monozygotic pairs, no differences were observed. In men, all three types of sports were individually associated with smaller WC, while in women, only mixed and power sports showed this association. Conclusions: Participation in several sport disciplines and sport types was associated with smaller WC among young adults in their mid-30s. Shared genetic background may explain some of the associations.  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