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   13576篇
  免费   126篇
  国内免费   122篇
教育   8974篇
科学研究   1667篇
各国文化   89篇
体育   1711篇
综合类   19篇
文化理论   168篇
信息传播   1196篇
  2021年   79篇
  2020年   155篇
  2019年   202篇
  2018年   949篇
  2017年   946篇
  2016年   722篇
  2015年   231篇
  2014年   244篇
  2013年   1568篇
  2012年   282篇
  2011年   516篇
  2010年   468篇
  2009年   358篇
  2008年   383篇
  2007年   487篇
  2006年   200篇
  2005年   249篇
  2004年   513篇
  2003年   432篇
  2002年   359篇
  2001年   402篇
  2000年   257篇
  1999年   162篇
  1998年   106篇
  1997年   106篇
  1996年   96篇
  1995年   107篇
  1994年   101篇
  1993年   77篇
  1992年   152篇
  1991年   119篇
  1990年   135篇
  1989年   149篇
  1988年   110篇
  1987年   129篇
  1986年   120篇
  1985年   135篇
  1984年   119篇
  1983年   123篇
  1982年   96篇
  1981年   81篇
  1980年   90篇
  1979年   134篇
  1978年   87篇
  1977年   72篇
  1976年   90篇
  1975年   65篇
  1974年   72篇
  1973年   68篇
  1971年   66篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
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   
142.
ABSTRACT

North Carolina Central University (NCCU) recognized the need to address the increasing rates of Ds, Fs, and Withdrawal by students matriculating in online courses. Led by two science faculty, a faculty learning community in partnership with the NCCU Division of Extended Studies was created to assess online science course offerings and instruction. Faculty within this learning community completed the Quality Matters (QM) “Applying the Quality Matters Rubric” course. This online training course, coupled with services provided by the NCCU Division of Extended Studies, offered the faculty learning community a variety of pedagogical strategies to meet their instructional needs. All faculty participating in this learning community completed the online training course and all faculty indicated that they implemented changes in their subsequent online course offerings. This article describes the impact of that training and the application of quality course design standards in the Quality Matters Rubric on the design and student outcomes for an Introductory Biology course over four terms. As faculty learning communities are broadly utilized, it is anticipated that this article may present an effective strategy to increase the quality and quantity of online science, technology, engineering and mathematics (STEM) courses at similar institutions.  相似文献   
143.
144.
145.
146.
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   
147.
148.
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   
149.
150.
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