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   24829篇
  免费   345篇
  国内免费   59篇
教育   17716篇
科学研究   2176篇
各国文化   488篇
体育   1795篇
综合类   46篇
文化理论   139篇
信息传播   2873篇
  2021年   252篇
  2020年   338篇
  2019年   494篇
  2018年   682篇
  2017年   736篇
  2016年   676篇
  2015年   444篇
  2014年   607篇
  2013年   4797篇
  2012年   611篇
  2011年   627篇
  2010年   556篇
  2009年   543篇
  2008年   614篇
  2007年   580篇
  2006年   567篇
  2005年   506篇
  2004年   412篇
  2003年   355篇
  2002年   320篇
  2001年   488篇
  2000年   439篇
  1999年   384篇
  1998年   232篇
  1997年   233篇
  1996年   231篇
  1995年   200篇
  1994年   214篇
  1993年   210篇
  1992年   334篇
  1991年   335篇
  1990年   359篇
  1989年   355篇
  1988年   275篇
  1987年   282篇
  1986年   282篇
  1985年   317篇
  1984年   296篇
  1983年   280篇
  1982年   223篇
  1981年   211篇
  1980年   216篇
  1979年   311篇
  1978年   238篇
  1977年   199篇
  1976年   189篇
  1975年   173篇
  1974年   183篇
  1973年   169篇
  1971年   177篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
901.
The living dead     
  相似文献   
902.
The objectives of this study were to determine nurses' use of electronic databases to inform practice. A questionnaire survey of 114 nurses working on five acute wards in a large inner city teaching hospital investigated their general use of computers and the three databases, CINAHL, MEDLINE and the Cochrane Library. Eighty-two qualified nurses responded (response rate 72%). The results show limited confidence and low frequency in using the databases. Thirty-four per cent expressed low confidence using CINAHL. Twenty-seven per cent used CINAHL on a regular basis. Twenty-two per cent never used it. Eighteen per cent were unaware that it was available locally. Knowledge and use of MEDLINE was even lower with only 18% using it regularly. Knowledge of the Cochrane Library was extremely limited, with 75% unaware of its existence. Use of a home computer and higher education were associated with higher frequency of use of CINAHL and MEDLINE. If nurses are to make use of electronic resources to contribute to evidence-based practice, effort needs to be put into ensuring that already qualified nurses have basic computer skills and specific knowledge of available resources. More emphasis should be placed on 'evidence-based' resources, such as the Cochrane library, as sources of information for practice.  相似文献   
903.
904.
Academic medical librarians responsible for monograph acquisition face a challenging task. From the plethora of medical monographs published each year, academic medical librarians must select those most useful to their patrons. Unfortunately, none of the selection tools available to medical librarians are specifically intended to assist academic librarians with medical monograph selection. The few short core collection lists that are available are intended for use in the small hospital or internal medicine department library. As these are the only selection tools available, however, many academic medical librarians spend considerable time reviewing these collection lists and place heavy emphasis on the acquisition of listed books. The study reported here was initiated to determine whether the circulation of listed books in an academic library justified the emphasis placed on the acquisition of these books. Circulation statistics for "listed" and "nonlisted" books in the hematology (WH) section of Indiana University School of Medicine's Ruth Lilly Medical Library were studied. The average circulation figures for listed books were nearly two times as high as the corresponding figures for the WH books in general. These data support the policies of those academic medical libraries that place a high priority on collection of listed books.  相似文献   
905.
906.
The paper considers how attributes and skills fundamental to the information profession may be applied to the development and management of Web-based services and resources. It also looks at the need for the acquisition of new skills as part of a continuing professional development programme. The report considers the changing role of the Webmaster and the implications this might have in terms of the role of information professionals. To offer a practical example, from within the healthcare sector, the article goes on to describe the development of BMA Library Online. This is the BMA Library's own suite of Web-based information services and resources for personal members, institutional members and staff. The library's own Web team has been responsible for the development and maintenance of BMA Library Online. To conclude, the paper looks forward to future possibilities for information professionals as Web developers and at how this might be influenced by changes in the Webmaster role. It is crucial that skills and expertise are shared as the roles that go to make up a Webmaster or Webmaster team continue to merge and evolve, and with the possible wider distribution of provision of Web content within organizations.  相似文献   
907.
908.
The purpose of this study was to develop a submaximal, 1.5-mile endurance test for college-aged students using walking, jogging, or running exercise. College students (N = 101: 52 men, 47 women), ages 18-26years, successfully completed the 1.5-mile test twice, and a maximal graded exercise test. Participants were instructed to achieve a "somewhat hard" exercise intensity (rating of perceived exertion = 13) and maintain a steady pace throughout each 1.5-mile test. Multiple linear regression generated the following prediction equation: VO2 max = 65.404 + 7.707 x gender (1 = male; 0 =female) - 0.159 x body mass (kg) - 0.843 x elapsed exercise time (min; walking, jogging orrunning). This equation shows acceptable validity (R = .86, SEE = 3.37 ml x kg(-1) min(-1)) similar to the accuracy of comparable field tests, and reliability (ICC = .93) is also comparable to similar models. The statistical shrinkage is minimal (R(press) = 0.85, SEE(press) = 3.51 ml x kg(-) x min(-1)); hence, it should provide comparable results when applied to other similar samples. A regression model (R =.90, and SEE = 2.87 ml x kg(-1) min(-1)) including exercise heart rate was also developed: VO2 max = 100.162 +/- 7.301 x gender(1 = male; 0 =female) - 0.164 x body mass (kg) - 1.273 x elapsed exercise time -0.156 x exercise heart rate, for those who have access to electronic heart rate monitors. This submaximal 1.5-mile test accurately predicts maximal oxygen uptake (VO2max) without measuring heart rate and is similar to the 1.5-mile run in that it allowsfor mass testing and requires only a flat, measured distance and a stopwatch. Further, it can accommodate a wide range of fitness levels (from walkers to runners).  相似文献   
909.
910.
Different methods of ball carrying can be used when a player runs with the ball in rugby union. We examined how three methods of ball carrying influenced sprinting speed: using both hands, under the left arm and under the right arm. These methods were compared with running without the ball. Our aim was to determine which method of ball carrying optimizes sprinting speed. Altogether, 48 rugby union players (age 21 +/- 2 years, height 1.83 +/- 0.1 m, body mass 85.3 +/- 12 kg, body fat 14 +/- 5%; mean +/- s) were recruited. The players performed twelve 30-m sprints in total (each player performed three trials under each of three methods of carrying the ball and sprinting without the ball). The design of the study was a form of Latin rectangle, balanced across the trial order for each of the methods and for pairwise combinations of the methods in blocks of four per trial. Each sprint consisted of a 10-m rolling start, followed by a 20-m timed section using electronic timing gates. Compared with sprinting 20 m without the ball (2.58 +/- 0.16 s), using both hands (2.62 +/- 0.16 s) led to a significantly slower time (P < 0.05). Sprinting 20 m with the ball under the left arm (2.61 +/- 0.15 s) or under the right arm (2.60 +/- 0.17 s) was significantly quicker than when using 'both hands' (P < 0.05), and both these methods were significantly slower than when running without the ball (P < 0.05). Accordingly, running with the ball in both hands led to the greatest decrement in sprinting performance, although carrying the ball under one arm also reduced the players' sprinting ability. Our results indicate that to gain a speed advantage players should carry the ball under one arm.  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