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   21926篇
  免费   871篇
  国内免费   6篇
  2019年   295篇
  2018年   369篇
  2017年   334篇
  2016年   374篇
  2015年   269篇
  2014年   371篇
  2013年   1788篇
  2012年   628篇
  2011年   699篇
  2010年   424篇
  2009年   439篇
  2008年   557篇
  2007年   579篇
  2006年   558篇
  2005年   451篇
  2004年   478篇
  2003年   441篇
  2002年   445篇
  2001年   644篇
  2000年   699篇
  1999年   489篇
  1998年   256篇
  1996年   212篇
  1992年   387篇
  1991年   391篇
  1990年   394篇
  1989年   368篇
  1988年   351篇
  1987年   325篇
  1986年   342篇
  1985年   355篇
  1984年   279篇
  1983年   280篇
  1982年   205篇
  1981年   201篇
  1980年   213篇
  1979年   352篇
  1978年   272篇
  1977年   199篇
  1976年   209篇
  1975年   289篇
  1974年   339篇
  1973年   357篇
  1972年   292篇
  1971年   283篇
  1970年   236篇
  1969年   270篇
  1968年   313篇
  1967年   318篇
  1966年   255篇
排序方式: 共有10000条查询结果,搜索用时 240 毫秒
831.
Recognition memory for matrices of 0s and 1s was examined as a function of the number of elements (complexity) and density of those elements within the matrix. It was found that with greater density and lesser complexity, recognition performance improved. This result contradicts an earlier finding of Green and Purohit, who concluded that the more complicated matrices led to better performance. The present study suggests that their conclusion was erroneous and stemmed from failure to control the physical parameters of density and number of elements in the matrix. Implications for the general problem of recognition memory and eye movements are discussed.  相似文献   
832.
833.
Peripheral processes in vision were investigated in two experiments involving monoptic backward masking with random noise. For young and old subjects, peripheral processing time (represented by stimulus onset asynchrony of target and mask) was characterized as a power function of target energy. Although processing time for both age groups showed a similar rate of decline with increasing target energy, old subjects processed targets more slowly at all energy levels. Results were independent of education, sex, and criterion differences between young and old. Target duration was related to critical interstimulus interval, such that stimulus onset asynchrony between target and mask was approximately constant for a given target energy within each age group. Evidence suggests that peripheral processing begins with target onset and that processing time is best characterized by a power function relating stimulus onset asynchrony of target and mask to target energy.  相似文献   
834.
This series of experiments demonstrated that compound conditioned stimuli (CSs) highly conditioned in isolation lose conditioned response strength when compound-CS-unconditioned stimulus (US) pairings are given. This loss in conditioned responding was a positive function of the number of compound-CS-US pairings and was greater for the more salient stimulus. Finally, if a previously neutral stimulus was compounded with two previously conditioned cues, the neutral stimulus could acquire conditioned inhibitory properties with only compound-CS-US pairings. These results provide support for some aspects of the Rescorla-Wagner model.  相似文献   
835.
Private self-consciousness consists of attending to one's thoughts, feelings, and motives. Public self-consciousness consists of attending to oneself as a social object. The effect of dispositional self-consciousness on the accuracy of self-reports was studied in research on aggression. High- and low-private self-conscious subjects rated their own aggressiveness. Several weeks later their aggressive behavior was objectively measured. The correlation between self-report of aggressiveness and aggressive behavior was significantly higher for high-than for low-private self-conscious subjects. The correlation between self-report and behavior was unaffected by public self-consciousness. The implications of these findings for self-consciousness theory and personality dispositions are discussed.  相似文献   
836.
837.
A simple input and output circuit is described that allows users to sense contact closures and to drive relays from a Digital Equipment Corporation LSI-11 DRV 11 parallel interface board or a signal-compatible equivalent.  相似文献   
838.
839.
An experiment was conducted in which subjects matched upper and lower case versions of well-known abbreviations, such as BBC and etc, and meaningless controls. “Same” RT showed a familiarity effect for upper case versions of abbreviations such as BBC and GPO, but not for the lower case versions bbc and gpo. The converse did not occur for abbreviations such as etc, which were thought to occur most frequently in lower case. The “different” RT was inhibited by familiarity, with pairs such as IBM GPO being classified less rapidly than their lower case versions or controls. These effects occurred for subjects instructed to report “No” for “same” displays and “Yes” for “different” displays as well as for subjects given a conventional decision-report assignment. Some implications of these results for an account of the manner in which familiarity affects graphemic comparison processes are considered.  相似文献   
840.
Two experiments investigated the capacity of a nominal CS to overshadow background stimuli. Rats received CS-shock pairings in one compartment of a double compartment apparatus. After training the shock compartment was represented, but in the absence of both the CS and shock. Overshadowing was then assessed by measuring rats' latency to enter this compartment. If rats readily entered the shock compartment this indicated that the background cues in that compartment had acquired little or no associative strength during training, and overshadowing was therefore inferred. If however rats avoided the shock compartment, then this indicated that the background stimuli must have become aversive during training, and overshadowing could not then be inferred. In both experiments it was found that the capacity of a CS to overshadow background stimuli was directly related to the amount of training given. The experiments also showed that this capacity is inversely related to shock intensity. The results are discussed in terms of Rescorla and Wagner's (1972) model of conditioning.  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