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   22384篇
  免费   2473篇
  国内免费   1571篇
  26428篇
  2023年   388篇
  2022年   391篇
  2021年   477篇
  2020年   910篇
  2019年   878篇
  2018年   845篇
  2017年   942篇
  2016年   934篇
  2015年   640篇
  2014年   814篇
  2013年   2407篇
  2012年   560篇
  2011年   727篇
  2010年   540篇
  2009年   804篇
  2008年   956篇
  2007年   1022篇
  2006年   977篇
  2005年   835篇
  2004年   751篇
  2003年   639篇
  2002年   580篇
  2001年   399篇
  2000年   388篇
  1999年   323篇
  1998年   272篇
  1997年   252篇
  1996年   200篇
  1995年   199篇
  1994年   195篇
  1993年   137篇
  1992年   120篇
  1991年   107篇
  1990年   98篇
  1989年   66篇
  1988年   81篇
  1987年   90篇
  1985年   423篇
  1984年   471篇
  1983年   391篇
  1982年   503篇
  1981年   494篇
  1980年   488篇
  1979年   452篇
  1978年   489篇
  1977年   416篇
  1976年   410篇
  1975年   307篇
  1974年   281篇
  1973年   236篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
Two experiments examined the effectiveness of two amounts of flooding or response-prevention on hastening avoidance response extinction and on reducing CS-produced suppression of bar-pressing for food. In Experiment 1, 20 and 30 flooding trials were both shown to be effective in hastening the extinction of a well-learned shuttlebox avoidance response. In Experiment 2, rats trained under comparable conditions to those in Experiment 1 were tested following flooding for the CER in a different apparatus. The results indicated that 30, but not 20, flooding trials were sufficient to reduce the CER. In each experiment the results of additional control groups equated with the flooded groups for nonreinforced CS exposure also revealed a dissociation between the effectiveness of this CS time control procedure in hastening avoidance response extinction and in reducing the CER. Further comparisons showed that although 30 flooding trials did reduce the CER, the same total duration of nonreinforced CS Exposure in the form of avoidance extinction trials did not. Thus the context in which CS exposure occurs may affect the dynamics of extinction of the CER. The experiments are discussed in the broader context of dissociation of various indices of fear in humans.  相似文献   
952.
In three experiments, the retention of conditioned inhibition in rats was examined over long intervals. Retention deficits of conditioned inhibition were found at 21 days, although conditioned excitation was relatively stable over time. This loss of conditioned inhibition was demonstrated using both the summation and the retardation of learning techniques in a bar-press suppression paradigm. Furthermore, retention differences were found between within-groups and between-groups generalization tests of conditioned inhibition, using the summation procedure. These differences were interpreted within a retrieval-oriented model of memory.  相似文献   
953.
In a two-key concurrent variable-interval schedule (using pigeons), if the reinforcement frequency for one response is held constant while that for the other is increased, the rate of response on the constant key decreases. The immediate reinforcement for key pecking can usually be conceptualized as the change from a condition in which the key light is on and the food hopper light is off to one in which the key light is off and the hopper light is on. The prechange condition is associated with a delay to food of one-half the average interreinforcement interval in effect during this condition. The postchange condition is associated with a delay to food of about .5 seconds. The programming of additional reinforcement results in a decrease in the delay to food associated with the prechange stimulus condition, and thus a decrease in the value of the improvement that results from the change. This would appear to be analogous to a decrease in the amount of reinforcement, and thus sufficient explanation for the decrease in the rate of the response.  相似文献   
954.
Temporal control of behavior and the power law   总被引:9,自引:9,他引:0       下载免费PDF全文
The performance of rats and pigeons under fixed-interval schedules was studied in two experiments. The duration of postreinforcement pause was a declining proportion of fixed-interval duration. For pigeons this was true both when the duration of the reinforcer was fixed and when it was increased in direct proportion to increases in fixed-interval duration; the longer reinforcer durations did, however, lengthen the postreinforcement pause at higher schedule values. A quantitative analysis of data from Experiments 1 and 2 and from other studies showed that fractional exponent power functions described the relationship between postreinforcement pause and fixed-interval value; similar functions have previously been observed in studies of temporal differentiation. It was concluded that power functions reflect a direct causal, rather than artifactual, relationship between performance and the temporal requirements of reinforcement schedules.  相似文献   
955.
Lloyd Bond 《Psychometrika》1979,44(3):351-355
Tucker, Damarin and Messick proposed a base-free measure of change which involves the computation of residual scores that are uncorrelated with true scores on the pretest. The present note discusses this change measure and demonstrates that, because of an incorrect derivation by the authors, properties they attribute to (the coefficient for the regression of true scores from the second testing on true scores from the first testing) are, in fact, properties ofb, the ordinary regression coefficient. A correct derivation of the initial position—change correlation in terms of is obtained, and Tucker et al.'s discussion of the law of initial values is reconsidered.The preparation of this paper was supported by the Learning Research and Development Center supported in part as a research and development center by funds from the National Institute of Education.  相似文献   
956.
This experiment examined the role of cognitive flexibility-rigidity in memory. On the basis of several personality tests, subjects were classified as flexible, intermediate, or rigid, using a postexperimental blocking procedure. All subjects were given a perceptual grouping task, which masks the meaningful structure of the material. Subjects have the option of discovering the more meaningful structure consisting of word pairs, or alternatively, processing less meaningful chunks of letters. Results were that flexible subjects recalled substantially more items than intermediate and rigid subjects, in that order. In addition, subjects given different (varied) groupings of the letter chunks recalled substantially more than subjects given repeated presentations of the same grouping structure. Transfer tests indicated that subjects acquired different coding strategies under varied and constant input. Repetitious input led subjects to adopt inefficient strategies in processing the material to be remembered, whereas varied input led subjects to adopt efficient encoding strategies.  相似文献   
957.
This study investigated recognition memory of photographs of the subject's own face. Male and female subjects were photographed as they projected sociable faces, trustworthy faces, and intelligent faces. After deciding which face of 10 best represented each characteristic, and judging which photograph best represented their “real self,” a recognition memory test of poses was given. Half of each sex were tested under intentional learning conditions and the remainder were tested under incidental learning conditions. Females demonstrated superior recognition memory of their own facial projections and, in particular, recalled photographs of their “real self” and “most sociable” self most easily. No differences were found between the two learning conditions. Subjects' recognition performance was not related to their confidence of judgments. The results were discussed in terms of sex differences and the role of self in memory.  相似文献   
958.
The illusion of control, the tendency for individuals to approach chance tasks with skill-appropriate strategies, was studied. Subjects premeasured on a mania scale were classified as either high (HM) or low (LM) in mania. In the first phase of the study, HM and LM subjects performed 30 trials on either a skill (verbal associates) or chance (coin-toss) task and were given either 20, 50, or 80% success feedback. After Task 1 was completed, subjects filled out an attribution questionnaire. In the final phase of the study, subjects anticipated 30 more trials either on a skill or chance task. Subjects' predicted successes were measured. It was hypothesized that predicted successes on anticipated skill and chance tasks would be affected more by outcomes on a previous skill task than by outcomes on a previous chance task. The results for the anticipated skill task directly supported the hypothesis. On the anticipated chance task, the hypothesis was confirmed for HM subjects only. The results are discussed in terms of how previous skill experiences may induce a set to control ungovernable situations for individuals with manic reactions.  相似文献   
959.
Objective tests of personality typically include a number of items or trials; the total score on the test is the sum of the subject's “correct” responses across all such trials. Normally, the trials are varied systematically across various facets of the test design, so that the total score represents a composite measure of accuracy averaged across these test facets. However, since only one score is computed for each subject, some potentially important kinds of individual differences—namely all those associated with each particular variation in the test design—are treated solely as measurement unreliability. Such a psychometric stance may serve to obscure more differentiated types of individual differences, with the result that composite scores from trials based on one type of experimental design may not be highly related to such scores from trials using a somewhat different design. The present paper presents a general procedure for scoring objective tests more analytically. To illustrate this general rationale, and to demonstrate its potential utility, data have been reanalyzed from two previous studies, one using the Rod-and-Frame test, the other the Müller-Lyer illusion. In both cases, the traditional global accuracy score did not correlate significantly with other theoretically related variables, while a number of component scores were quite highly related.  相似文献   
960.
A series of studies investigating the psychometric and conceptual properties of the Survey of Ethical Attitudes (SEA), a paper-and-pencil measure of moral reasoning, is reported. The results of these studies indicate that the scale is clearly susceptible to the influence of response dissimulation in the form of both role-playing and impression management, and is also confounded with sources of stylistic variance in the form of social desirability. Previous proposals concerning the relationships among moral development, moral reasoning, and personality structure are reviewed in light of these findings, and an alternative conceptualization of the measure in terms of political and social attitudes is offered.  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