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   5548篇
  免费   284篇
  国内免费   13篇
  2023年   50篇
  2022年   51篇
  2021年   57篇
  2020年   121篇
  2019年   139篇
  2018年   191篇
  2017年   167篇
  2016年   197篇
  2015年   103篇
  2014年   138篇
  2013年   589篇
  2012年   229篇
  2011年   276篇
  2010年   168篇
  2009年   160篇
  2008年   209篇
  2007年   222篇
  2006年   193篇
  2005年   180篇
  2004年   157篇
  2003年   149篇
  2002年   147篇
  2001年   121篇
  2000年   90篇
  1999年   77篇
  1998年   76篇
  1997年   52篇
  1996年   58篇
  1995年   58篇
  1994年   61篇
  1993年   43篇
  1992年   62篇
  1991年   78篇
  1990年   60篇
  1989年   57篇
  1988年   57篇
  1987年   54篇
  1986年   53篇
  1985年   55篇
  1984年   39篇
  1983年   42篇
  1982年   48篇
  1981年   47篇
  1979年   49篇
  1978年   58篇
  1977年   46篇
  1976年   42篇
  1975年   46篇
  1974年   44篇
  1973年   48篇
排序方式: 共有5845条查询结果,搜索用时 31 毫秒
61.
The effects of backward masker “fringe” on performance in homophasic and antiphasic masking conditions were investigated. The results of the study indicate that (1) the presence of a backward masker fringe has only a small effect on performance in homophasic masking conditions; (2) under antiphasic masking conditions, the presence of a backward masker fringe improves performance; (3) similar to the results of studies investigating the effects of forward masker fringe, the magnitude of the improvement in performance increases as the duration of the fringe increases; and (4) the magnitude of the improvement caused by the presence of backward masker fringe is considerably smaller than the magnitude of the improvement caused by the forward masker fringe. It appears, then, that the presence of backward masker fringe may provide a baseline or reference phase similar to that which the forward fringe is presumed to provide. The presence of this reference phase after the offset of the signal apparently makes the phase shift associated with the signal-plus-noise waveform more discernible, thus leading to higher detectability. However, for reasons not yet clear, the presence of a baseline or reference phase after the offset of the signal (backward fringe conditions) does not make the signal-plus-noise phase shift as discernible as do either the presence of that same reference phase before the onset of the signal (forward fringe condition) or the presence of that same reference phase both before signal onset and after signal offset (continuous masker condition).  相似文献   
62.
63.
A set of devices is described that enables daily handling and restraint of large primates. The animals live in cages and wear a special collar that fits into a modified primate restraining chair. A chain and pole arrangement simplifies the daily chairing procedure. A method of head restraint and earphone mounting is also described.  相似文献   
64.
The plastic barrel suit provides complete protection of chronically implanted fistulas and electrical connectors. The lost time, expense, and the frustrations of having these devices damaged was avoided.  相似文献   
65.
Some punishing effects of response-force   总被引:1,自引:1,他引:0       下载免费PDF全文
The present experiment explored the punishing effect of different response-force requirements by means of a two-operant design analogous to a two-component chain schedule. The first component of the chain required a lever pull through 0.25 in. (0.64 cm) at 1 lb (4.45 N) of force. The second component required a lever pull through an additional 0.75 in. (1.90 cm) with the force varied between sessions from 1 lb to 50 lb (4.45 N to 223 N). Completion of the second component of the chain was reinforced after variable intervals averaging 1 min. The average rate of first-component response decreased as the force requirement for second-component responses was increased. This rate reduction did not appear to be due to increased response duration, “fatigue”, or differing rates of reinforcement. If the force requirement for the second-component response is viewed as a consequence for the first-component response, then the results of the experiment show that a high force requirement is a punisher.  相似文献   
66.
67.
The attendance rates of welfare recipients at self-help group meetings was compared when supplementary reinforcement was given for attending and when it was not. Reinforcers included donated items, such as clothing and household goods, and information about welfare services. It was found that the attendance at meetings averaged three recipients per meeting without reinforcement and 15 recipients per meeting with reinforcement. There was evidence that attendance was associated with participation in other self-help activities. It was concluded that practical forms of reinforcement can be found to maintain the participation of severely disadvantaged populations in self-help groups.  相似文献   
68.
Subjects evaluated three stimulus persons on several rating scales who were either 10%, 50%, or 90% similar to themselves in attitudes Subjects were divided into low, moderate, and high self-esteem groups on the basis of an earlier Q sort The results showed a strong positive relation between perceived similarity and positive attribution for each of the dependent variables, including liking, sophisticated, intelligent, sincere, happy, and a social distance scale A negative relation was obtained for two undesirable traits, arrogant and cynical Self-esteem interacted with similarity on several of the measures The difference between self-esteem groups was largely restricted to highly dissimilar stimulus persons Moderate esteem subjects were more favorable toward dissimilar persons than either of the other two groups, and the high and low groups tended to resemble each other more than either group resembled the moderate esteem group These results were discussed in terms of the relation between self-esteem and adjustment, and in terms of McGuire's (1968) theory that predicts a nonmonotonic relation between self-esteem and attitudes.  相似文献   
69.
70.
Factors in school achievement and social class   总被引:2,自引:0,他引:2  
  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