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   1993篇
  免费   40篇
  国内免费   3篇
教育   1437篇
科学研究   83篇
各国文化   21篇
体育   193篇
综合类   1篇
文化理论   17篇
信息传播   284篇
  2023年   8篇
  2022年   11篇
  2021年   20篇
  2020年   41篇
  2019年   72篇
  2018年   89篇
  2017年   99篇
  2016年   88篇
  2015年   68篇
  2014年   73篇
  2013年   462篇
  2012年   53篇
  2011年   56篇
  2010年   38篇
  2009年   50篇
  2008年   57篇
  2007年   44篇
  2006年   54篇
  2005年   55篇
  2004年   47篇
  2003年   48篇
  2002年   33篇
  2001年   23篇
  2000年   25篇
  1999年   18篇
  1998年   20篇
  1997年   13篇
  1996年   24篇
  1995年   14篇
  1994年   15篇
  1993年   22篇
  1992年   14篇
  1991年   10篇
  1990年   13篇
  1989年   14篇
  1988年   22篇
  1987年   8篇
  1986年   11篇
  1985年   18篇
  1984年   12篇
  1982年   17篇
  1981年   7篇
  1980年   8篇
  1979年   7篇
  1978年   7篇
  1977年   11篇
  1976年   8篇
  1973年   10篇
  1970年   7篇
  1968年   11篇
排序方式: 共有2036条查询结果,搜索用时 15 毫秒
81.
82.
OBJECTIVES: Medicine must keep current with the research literature, and keeping current requires continuously updating the clinical knowledge base (i.e., references that provide answers to clinical questions). The authors estimated the volume of medical literature potentially relevant to primary care published in a month and the time required for physicians trained in medical epidemiology to evaluate it for updating a clinical knowledge base. METHODS: We included journals listed in five primary care journal review services (ACP Journal Club, DynaMed, Evidence-Based Practice, Journal Watch, and QuickScan Reviews). Finding little overlap, we added the 2001 "Brandon/Hill Selected List of Print Books and Journals for the Small Medical Library." We counted articles (including letters, editorials, and other commentaries) published in March 2002, using bibliographic software where possible and hand counting when necessary. For journals not published in March 2002, we reviewed the nearest issue. Five primary care physicians independently evaluated fifty randomly selected articles and timed the process. RESULTS: The combined list contained 341 currently active journals with 8,265 articles. Adjusting for publication frequency, we estimate 7,287 articles are published monthly in this set of journals. Physicians trained in epidemiology would take an estimated 627.5 hours per month to evaluate these articles. CONCLUSIONS: To provide practicing clinicians with the best current evidence, more comprehensive and systematic literature surveillance efforts are needed.  相似文献   
83.
This study examined age-related differences in the role of visual proprioception during a lower limb interceptive action and how this varies as a function of skill and practice. In Experiment 1, skilled and less-skilled 8-, 10-, and 12-year-old boys controlled a soccer ball using their preferred foot under full vision and when sight of the effector was occluded. With the exception of the high-skilled 12-year-olds and low-skilled 8-year-olds, participants showed a decrement in peformance when denied access to visual proprioception. In Experiment 2, the effect of practicing under different informational constraints was examined for 12 year-old boys. Children performed varying amounts of practice under full vision, or in a condition where sight of the foot was occluded, before being transferred to the alternative viewing condition. Participants who practiced under occluded viewing conditions showed greater relative improvement in performance over practice and transfer sessions compared with a full vision control group. Some support is provided for the manipulation of visual informational constraints as an effective pedagogical approach to motor learning.  相似文献   
84.
A mathematical model relating power output of rower to stroke rate on an ergometer (the Concept II Indoor Rower TM, Model C) is studied. The model is used to analyse the ergometer performance of a particular rower. It is determined that he can be more efficient (i.e. decrease power output while maintaining fixed velocity) by decreasing stroke rate, but at the expense of increasing force during the drive. It is also shown that he can be more efficient by increasing the drag factor (using higher vent setting) without increasing force. Dependence of power output on rowing style (the shape of the force curve) is also examined. It is shown that variation of force during the drive has little effect on efficiency, but efficiency is reduced by asymmetry of the force curve that favours the legs.  相似文献   
85.
In June 2000, the Biomedical Library at the University of South Alabama introduced Prospero, an electronic desktop document delivery service. From June 2000 to November 2002, Prospero delivered 28% of interlibrary loan requests and 72% of document delivery requests. In November 2002, the library conducted a user satisfaction survey of the Prospero service. Forty-two surveys were used. Fifteen responses were received from affiliated faculty, staff, and students, who generally expressed satisfaction with the service. Twenty-seven responses were received from unaffiliated users, comprised of medical libraries, individual users, and businesses. Based on the survey results, the library deemed the Prospero service a success. To better support users, the library's Web page was updated to include hardware and software requirements for successful use of the Prospero service, as well as screen shots of the Prospero process.  相似文献   
86.

Other Index

Index to Volume XLI  相似文献   
87.
88.
89.
90.
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