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   9307篇
  免费   96篇
  国内免费   18篇
教育   6281篇
科学研究   1045篇
各国文化   90篇
体育   996篇
综合类   6篇
文化理论   96篇
信息传播   907篇
  2021年   70篇
  2020年   122篇
  2019年   175篇
  2018年   238篇
  2017年   252篇
  2016年   218篇
  2015年   153篇
  2014年   216篇
  2013年   1694篇
  2012年   200篇
  2011年   197篇
  2010年   170篇
  2009年   152篇
  2008年   170篇
  2007年   194篇
  2006年   160篇
  2005年   150篇
  2004年   141篇
  2003年   169篇
  2002年   138篇
  2001年   157篇
  2000年   157篇
  1999年   155篇
  1998年   72篇
  1997年   74篇
  1996年   109篇
  1995年   77篇
  1994年   95篇
  1993年   87篇
  1992年   153篇
  1991年   146篇
  1990年   138篇
  1989年   136篇
  1988年   114篇
  1987年   116篇
  1986年   138篇
  1985年   134篇
  1984年   107篇
  1983年   129篇
  1982年   110篇
  1981年   104篇
  1980年   95篇
  1979年   165篇
  1978年   110篇
  1977年   108篇
  1976年   104篇
  1975年   79篇
  1974年   89篇
  1972年   70篇
  1971年   70篇
排序方式: 共有9421条查询结果,搜索用时 0 毫秒
71.
72.
73.
74.
75.
It is very difficult, if not impossible, to remove the last traces of hypo from photographic papers by any known procedure of washing. The sulfur in the residual hypo ultimately, and especially under abnormal conditions of temperature and humidity, combines with the silver image to form yellowish brown silver sulfide. This phenomenon is known as sulfiding or “fading” of the image. The various factors which affect the rate of fading of images and the washing out of hypo from films and papers are outlined.Chemical methods of hypo elimination have been proposed from time to time but the majority of these have not been satisfactory because they tend to leave substances such as thionates in the photographic material, which are equally as difficult to wash out as hypo and which also tend to sulfide or fade the silver image. A new hypo eliminator is recommended consisting of two volatile chemicals, hydrogen peroxide and ammonia. This eliminator oxidizes the hypo to sodium sulfate, which is inert and soluble in water, while any excess eliminator evaporates on drying.Two formulas and treatments are proposed: (1) Complete elimination of hypo for use by the professional, advanced amateur, and photofinisher who demand the highest standard of photographic quality in their prints.(2) Almost complete elimination of hypo (less than o.oi milligram per square inch).Since the conditions to which prints will be subjected are rarely known in advance, use of the “complete elimination treatment” is advised in all cases.  相似文献   
76.
77.
78.
79.
ABSTRACT

Relying on Marianne Hirsch’s work on postmemory, as well as theories about new media and memory, this study explores how a group of Armenian young adults in Toronto remember the Armenian Genocide from afar, 100 years after it happened. The data come from 100 Voices: Survival, Memory, Justice. Through a thematic and visual analysis of a sample of video clips posted on YouTube, this study argues that 100 Voices is a work of postmemory that stands at the intersection of prevailing ethno-nationalist constructions of Armenian identity on the one hand, and universal discourses of human rights and historical justice, on the other. Participants are positioned as the Armenian youth, performing a particular duty of memory to remember the genocide and transmit genocide memories to future generations. At the same time, 100 Voices enables these youths to emerge as activists who express their group-based claims through universal parameters of claim-making.  相似文献   
80.
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   
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