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   10334篇
  免费   575篇
  国内免费   5篇
  2021年   85篇
  2020年   172篇
  2019年   201篇
  2018年   274篇
  2017年   338篇
  2016年   328篇
  2015年   222篇
  2014年   281篇
  2013年   1244篇
  2012年   432篇
  2011年   461篇
  2010年   293篇
  2009年   305篇
  2008年   428篇
  2007年   426篇
  2006年   347篇
  2005年   365篇
  2004年   328篇
  2003年   298篇
  2002年   301篇
  2001年   145篇
  2000年   167篇
  1999年   155篇
  1998年   156篇
  1997年   128篇
  1996年   140篇
  1995年   129篇
  1994年   122篇
  1993年   90篇
  1992年   132篇
  1991年   84篇
  1990年   89篇
  1989年   91篇
  1988年   94篇
  1987年   74篇
  1986年   90篇
  1985年   101篇
  1984年   114篇
  1983年   90篇
  1982年   112篇
  1981年   118篇
  1980年   104篇
  1979年   92篇
  1978年   91篇
  1977年   116篇
  1976年   90篇
  1975年   103篇
  1974年   87篇
  1973年   99篇
  1972年   72篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
Greeno and Steiner have shown that a three state Markov Chain with a single absorbing state is equivalent to many of the current formalizations of All-or-None learning theories. Distribution statistics and other summary statistics are derived from the general model. Expressions for the maximum likelihood estimators of its parameters and the sampling variances of the estimates are presented. Likelihood ratio tests for several different null hypotheses are derived. These tests permit one to evaluate the usual null hypotheses in terms of the parameters of a process model.This research was supported in part by a USPHS Predoctoral Research Fellowship, 1-F1-MH-31-289-01, by a grant from the Graduate School of the University of Texas, and by grant HD-02212-01 from the National Institute of Child Health and Human Development to Dr. John Theios.  相似文献   
142.
Student personnel services for the elementary school utilizing counselor, social worker, and psychologist are discussed with respect to their overlapping and unique skills. As a solution to the manpower shortage, a program for multidisciplinary training of paraprofessionals is suggested.  相似文献   
143.
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   
144.
Stochastically textured patterns were used to investigate the sensitivity of Ss to differences in the statistical distributions of locally defined properties of element density and shape. The results of the study indicate that when the textures were most structured, in terms of their variance, Ss were most accurate at detecting dissimilarities between pairs of patterns. Ss also rated the similarity of the statistical distributions of elements of patterns differing in local properties. Multidimensional scaling analysis of the ratings showed two dimensions, representing monotonic orderings of the stimuli.  相似文献   
145.
Simultaneous recording from scalp and cortical electrodes in unanesthetized and unrestrained cats revealed essentially no differences between the superficial and deep recordings of the auditory evoked responses. Human recordings taken under two conditions of muscular contraction contained no major differences from 30 to 300 msec after stimulus onset.  相似文献   
146.
Animals were trained to displace any one of five response keys in order to put themselves in a stimulus condition in which reinforcement could be obtained by depressing a response lever. Decreased deprivation and magnitude of reinforcement were found to increase the variability of the distribution of key responses. The relevance of these findings to other experiments in which deprivation, reinforcement magnitude, and intermittent reinforcement were studied is discussed.  相似文献   
147.
The Journal of Value Inquiry -  相似文献   
148.
149.
Several methods for teaching serial position sequences to monkeys   总被引:1,自引:0,他引:1       下载免费PDF全文
Three keys were available for monkeys to press. The objective was to teach the animals to press the keys in sequences up to 10 members in length. With fading procedures, a light that cued the correct key at a given serial member of the sequence faded out slightly each time the animal selected it, and became slightly brighter after the animal made an error at that sequence member. The correct keys were faded out, starting from the end of the sequence and proceeding toward the beginning. With control procedures, the cue lights were turned off suddenly, rather than being faded gradually. In almost every instance, the animals learned a longer series of unlighted key positions with the fading procedures than they did when each key-light was turned off suddenly. Also, requiring the animals to press a series of keys cued by lights before they could reach the sequence members they were to learn hampered them in learning the later serial members. By using several different sequences, it was possible to replicate these findings within the individual animal.  相似文献   
150.
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