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   41320篇
  免费   1528篇
  国内免费   13篇
  42861篇
  2018年   633篇
  2017年   583篇
  2016年   674篇
  2015年   489篇
  2014年   609篇
  2013年   3954篇
  2012年   1002篇
  2011年   1068篇
  2010年   687篇
  2009年   689篇
  2008年   986篇
  2007年   924篇
  2006年   855篇
  2005年   735篇
  2004年   724篇
  2003年   743篇
  2002年   734篇
  2001年   1252篇
  2000年   1187篇
  1999年   923篇
  1998年   466篇
  1996年   558篇
  1995年   540篇
  1994年   533篇
  1993年   515篇
  1992年   977篇
  1991年   861篇
  1990年   857篇
  1989年   765篇
  1988年   775篇
  1987年   762篇
  1986年   745篇
  1985年   730篇
  1984年   672篇
  1983年   571篇
  1982年   477篇
  1981年   481篇
  1980年   465篇
  1979年   641篇
  1978年   520篇
  1976年   463篇
  1975年   620篇
  1974年   593篇
  1973年   643篇
  1972年   607篇
  1971年   554篇
  1970年   488篇
  1968年   565篇
  1967年   482篇
  1966年   469篇
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
981.
The effect of several reinforcement schedules on the variability in topography of a pigeon's key-peck response was determined. The measure of topography was the location of a key peck within a 10-in. wide by 0.75-in. high response key. Food reinforcement was presented from a magazine located below the center of the response key. Variability in response locus decreased to a low value during training in which each response produced reinforcement. Variability increased when fixed intervals, variable intervals, random intervals, or extinction were scheduled.  相似文献   
982.
983.
984.
985.
Three samples, each divided into males and females, were asked to indicate to what degree some job characteristics were important to them. The job characteristics represented both intrinsic and extrinsic factors. In the first sample (40 male and 44 female university students) there was no sex difference in job orientation. Both selected the intrinsic factors more than the extrinsic factors. There was also no sex difference in the second sample, which consisted of 68 male and 33 female public school teachers. They, however, stressed as many intrinsic factors as extrinsic. The general results of the third sample showed significant sex differences. The sample of 259 male and 143 female employees represented a technical division of a large service-oriented organization. Education and job level were significantly different for the two subgroups. When these two variables were controlled for a sample of clerks and of first-level supervisors, no sex difference appeared in job orientation. The results also showed that the higher the job level, the more intrinsically-oriented the employees were regardless of their sex.  相似文献   
986.
987.
988.
Subjects tried to recall the location of a tactile stimulus on the underside of the forearm after delays of 0, 3, 5, 10, 15, 30, 45 and 60 sec. When “rehearsal” was prevented by requiring subjects to count backwards during the delay, accuracy of recall decreased systematically reaching an asymptote after 45 sec. When subjects were left free to “rehearse,” this did not affect the decline in accuracy over the first 10 sec. Between 10 and 15 sec. there was a significant increase in accuracy followed by a slow decline which had not reached asymptote by 60 sec. It is suggested that tactile STM (short-term memory) depends on two processes, a fading sensory trace which is unaffected by distraction and a less labile system which does not appear to be verbal but which depends on “rehearsal.”  相似文献   
989.
Cardiac rates of rhesus monkeys were observed in a variety of different conditioning procedures, each of which involved a visual stimulus (CS) followed by an electric shock (US). With a 30-sec CS, cardiac rate accelerated rapidly after CS onset, reached a maximum in the middle of CS, and decelerated thereafter, with a terminal CS rate often at the level of, or below, pre-CS levels. A similar biphasic cardiac rate response in CS was also observed under subsequent exposure to intermittent pairings of CS and US, avoidance of US, response-produced termination of US, and when CS-US pairings were superimposed upon an avoidance baseline, even when CS duration was varied from 12 to 60 seconds. The unusual regularity of cardiac rate responses in several different procedures may result from one or more of these factors: (a) characteristics of the rhesus monkey, (b) initial exposure to Pavlovian conditioning, or (c) the uniformity of measurement of cardiac rate employed in this study.  相似文献   
990.
Procedures are described for the generation, synchronization. and accurate spacing of discrete dichotic stimulation material. A suggested standard definition of interpair interval is proposed.  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