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   23681篇
  免费   312篇
  国内免费   21篇
教育   15817篇
科学研究   3658篇
各国文化   199篇
体育   1736篇
综合类   21篇
文化理论   235篇
信息传播   2348篇
  2021年   233篇
  2020年   336篇
  2019年   486篇
  2018年   656篇
  2017年   668篇
  2016年   584篇
  2015年   404篇
  2014年   553篇
  2013年   4085篇
  2012年   541篇
  2011年   499篇
  2010年   457篇
  2009年   424篇
  2008年   449篇
  2007年   473篇
  2006年   406篇
  2005年   378篇
  2004年   391篇
  2003年   358篇
  2002年   367篇
  2001年   466篇
  2000年   504篇
  1999年   398篇
  1998年   217篇
  1997年   267篇
  1996年   278篇
  1995年   201篇
  1994年   224篇
  1993年   210篇
  1992年   319篇
  1991年   314篇
  1990年   339篇
  1989年   350篇
  1988年   295篇
  1987年   298篇
  1986年   318篇
  1985年   339篇
  1984年   275篇
  1983年   247篇
  1982年   233篇
  1981年   175篇
  1980年   169篇
  1979年   272篇
  1978年   210篇
  1977年   192篇
  1976年   166篇
  1975年   153篇
  1974年   171篇
  1973年   156篇
  1971年   156篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
This paper examines the increases in prices for the last twenty years for the journals listed in the 1987 Brandon/Hill list and for the last twelve years for those on a list of medical and general periodicals published annually in Library Journal. This information is compared to the general U.S. inflation rate as measured by the Consumer Price Index. Despite the decline in the general rate of inflation, the buying power of libraries has continued to dwindle. Librarians need to use this information when justifying increased budget requests. They also need to interact more effectively with publishers to resolve this problem. The buying power of the dollar (as compared to the 1975 dollar) spent on the Brandon/Hill list journals is now 59% of that of a dollar spent in the general economy. This compares to 64% in 1983, when this research was last updated.  相似文献   
943.
944.
The purpose of this study was to use generalizability theory with both univariate and multivariate approaches to examine reliability of total body center of mass (CM) values calculated from cinematographical data. Twenty-eight college-aged male volunteers were filmed by a LOCAM camera at 100 fps while performing the basic locomotion skill of walking. Film analysis was conducted on each subject using six frames of film depicting a one-stride walking cycle consisting of right heel strike, right foot flat, left toe-off, left heel strike, left foot flat, and right toe-off. Nineteen segmental endpoints and a reference point were digitized by three experienced plotters. The digitizing sequence was replicated three times by each plotter. A FORTRAN program calculated nine CM values (three plotters by three repetitions) for each subject filmed in each of the six positions of the stride. The x- and y-coordinates of the CM values were the dependent variables analyzed by fully crossed 3-way univariate and multivariate ANOVAs (subjects by plotters by repetitions). All measurement facets were considered to be random. Results indicate that there was very little repetition error but considerable interplotter error for most frames. Phi-coefficients for x- and y-coordinates, separately, fluctuated across frames. The univariate values for the x-coordinates were similar but slightly less than the multivariate values. The Phi-coefficients for Y, however, were considerably lower than the multivariate values. The multivariate Phi-coefficients for generalizing over three plotters and three repetitions ranged from .82 to .90.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
945.
946.
947.
948.
949.
950.
This paper is in the tradition of social analysis aimed at creatingframeworks to join mass media and public opinion processes (e.g.Clarke and Evans, 1983; Gamson, 1975; Gitlin, 1980; Hall, 1977;Iyengar and Kinder, 1987; Lang and Lang, 1968, 1983; Lippman,1922; Mollotch and Lester, 1974; Noelle-Neuman, 1974; Paletzand Entman, 1981; Shaw and McCombs, 1977; Turner and Paz, 1986).After a brief review of media system dependency (MSD) theory,we illustrate how it may apply to public opinion processes thatentail contested issue ‘value-frames’ (Ball-Rokeachand Rokeach, 1987). In such cases, the media system is directlyimplicated in the negotiation of legitimacy of opposing positionson an issue. Our illustrative case is the abortion issue asit has been played out in the United States over recent decades(Luker, 1984). We focus upon the respective capacities of pro-and anti-abortion movements to control the value-frame of mediacoverage of the issue (Guthrie, 1989). A value-frame may beconceived as ‘... the main substantive theme of a moralityplay’ (Ball-Rokeach and Tallman, 1979) wherein the distinctionbetween ‘good’ and ‘bad’ hangs in thebalance; in this case, between positions on abortion. We suggestthat change in the value-frame of media coverage and publicdiscourse may be understood, at least in part, as an outcomeof change in contestants' MSD relations.  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