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   6135篇
  免费   1502篇
  2021年   100篇
  2020年   136篇
  2019年   421篇
  2018年   324篇
  2017年   449篇
  2016年   446篇
  2015年   392篇
  2014年   344篇
  2013年   775篇
  2012年   384篇
  2011年   306篇
  2010年   308篇
  2009年   270篇
  2008年   290篇
  2007年   219篇
  2006年   208篇
  2005年   193篇
  2004年   156篇
  2003年   177篇
  2002年   180篇
  2001年   141篇
  2000年   149篇
  1999年   91篇
  1998年   60篇
  1997年   45篇
  1996年   44篇
  1995年   30篇
  1994年   27篇
  1993年   33篇
  1992年   46篇
  1991年   57篇
  1990年   34篇
  1989年   36篇
  1988年   31篇
  1987年   28篇
  1986年   29篇
  1985年   45篇
  1984年   28篇
  1983年   30篇
  1982年   30篇
  1981年   39篇
  1980年   35篇
  1979年   30篇
  1978年   30篇
  1977年   23篇
  1975年   33篇
  1974年   35篇
  1973年   28篇
  1972年   24篇
  1971年   23篇
排序方式: 共有7637条查询结果,搜索用时 31 毫秒
41.
When discriminated interresponse-time (IRT) procedures have been used to assess preference relations among temporally extended operants, deviations from matching have been obtained. Using a yoked-control procedure, the present study found that key pecking in a discriminated IRT procedure has two sources of strength--that arising from the response-reinforcer contingency that is explicitly arranged, and that arising from a stimulus-reinforcer contingency that is a by-product of the explicitly arranged contingency. The key pecking of all lead birds, and that of 3 of the 4 birds exposed to a yoked autoshaping procedure, was controlled by the keylight that signaled the lead birds' criterion IRTs. Because stimulus control of key pecking by the keylight, whether autoshaped or discriminative, fosters deviations from matching, the discriminated IRT procedure does not provide an appropriate basis for conclusions about preference relations among IRTs.  相似文献   
42.
Do alcoholic Korsakoff's syndrome patients acquire affective reactions?   总被引:1,自引:0,他引:1  
In this study we report two experiments that investigate the acquisition of affective reactions. In Experiment 1, unfamiliar melodies were played to Korsakoff's syndrome patients and alcoholic and nonalcoholic control subjects who were matched with them according to age and education. Following a retention interval of 5 min, subjects received a preference test on old and new melodies. Korsakoff's syndrome patients showed the same increase in preference for old melodies as a consequence of prior exposures as control subjects did, but their recognition of melodies was significantly impaired in comparison with controls. In Experiment 2, the same subjects saw photographs of two men. Fictional biographical information depicted one as a "good guy" and the other as a "bad guy." After a retention interval of approximately 20 days, Korsakoffs recalled virtually none of the biographical information; however, 78% preferred the good guy, and impression ratings were less favorable for the bad guy. Korsakoff patients developed preferences and impressions even though they did not have voluntary access to the information on which the preferences were based. However, their impression ratings were less extreme than those of controls. The pattern of results of the two studies is discussed in terms of Johnson's (1983) MEM model of memory.  相似文献   
43.
Sleep laboratory studies of patients complaining of insomnia have demonstrated discrepancies between subjective reports and electroencephalograph (EEG)-recorded measures. In our research studies on sleeping aids, 60% of the self-described poor sleepers who reported usual sleep latencies of at least 45 min did not meet the laboratory qualification criterion of a 30-min or longer sleep latency. To learn to predict who would qualify for our studies, we compared 30 laboratory-qualified poor sleepers (QPS) with 30 laboratory-disqualified poor sleepers (DPSs) on subjective report, mood, and all-night sleep laboratory variables. QPSs had significantly lower sleep efficiency and total sleep time in the laboratory, but these differences were due to the longer sleep latencies (50.7 +/- 27.8 min vs. 15.2 +/- 6.1 min) of the QPS group. QPSs and DPSs differed significantly in their morning estimates of their laboratory sleep latencies; as a group, QPSs gave an accurate estimate (51.6 +/- 27.8 min), but DPSs were significantly more likely to exaggerate their sleep latencies. Although we did not identify ways of predicting which poor sleepers would show sleep-onset insomnia in the sleep laboratory, we did find that, in this young, healthy population, there are poor sleepers who give an accurate report of a rather severe sleep-onset insomnia.  相似文献   
44.
Alcohol and social behavior II: the helpful drunkard   总被引:2,自引:0,他引:2  
Can alcohol make people more helpful, and if so, how? We hypothesized that alcohol would increase helping when, if the person were sober, the helping response would be under high inhibitory conflict--that is, when it would be affected by strong instigating and inhibiting pressures. Alcohol's damage to inhibitory processing should then allow instigating pressures to have more influence on the response, increasing helping. We expected that under low inhibitory conflict, when either or both of these response pressures would be weak under sobriety, alcohol would have little effect on helping. In two experiments we examined this reasoning. In Study 1, a mild dose of alcohol increased helping among high-conflict subjects pressured to help with a task they did not like, but did not increase helping among low-conflict subjects who either liked the task or were weakly pressured to help. In Study 2, a somewhat stronger dose of alcohol increased helping among all high-conflict subjects pressured to help with an undesirable task, yet again had no effect among low-conflict subjects weakly pressured to help. These studies provided an experimental demonstration of the role of inhibitory response conflict in mediating alcohol's social effects, and show that this process generalizes to prosocial behavior. Additional evidence from both experiments helped to rule out alternative explanations concerning drinking expectancies, alcohol's ability to enhance mood, and its ability to make the task more bearable.  相似文献   
45.
46.
In the present study, it was hypothesized that poorer performance of externals in cognitive and interpersonal tasks also would be found in the processing of nonverbal information in the form of a facial affect recognition task. It was further hypothesized that the poorer nonverbal processing performance of externals was due to either their lower motivation or their use of less effective processing strategies. Subjects (N = 70) were divided into internal and external groups and then further subdivided into groups that received standard, motivational, or strategy instructions. Analysis of subjects' responses to the facial affect recognition task showed internals performed significantly better than externals under standard conditions. However, neither motivational nor strategy instructions improved the performance of externals. The implications for interpersonal functioning of the poorer nonverbal processing ability of extenrals was discussed from both theoretical and methodological perspectives.  相似文献   
47.
How much is an icon worth?   总被引:1,自引:0,他引:1  
We report a new technique for assessing the amount of information extracted from the icon that follows a briefly presented picture. The problem of how to measure such information was formulated in terms of how much physical exposure of a picture an icon is worth. Consider two types of stimulus presentations, each with a base duration of d ms. The first is a d-ms picture followed by an icon, and the second is a d + a-ms picture not followed by an icon. How large does a have to be so that equivalent amounts of information are extracted in the two cases? To answer this question, we showed people pictures and later tested their memory for the pictures. We found that the physical exposure duration needed to reach a particular level of performance was approximately 100 ms longer when an icon was not permitted versus when the icon was permitted. This value was independent of the base duration and the luminance of the picture. Moreover, the same value was obtained using three different kinds of memory test and four different sets of pictures. We conclude that an icon is worth approximately 100 ms of additional physical exposure duration. A reasonable explanation for this robust equivalence between icon and stimulus is that the same encoding processes are responsible for extracting information from the icon and from the physical stimulus. Therefore, any variable that affects these encoding processes must affect extraction of information from the icon and the physical stimulus in an identical manner. This prediction was confirmed for one such variable, picture luminance.  相似文献   
48.
49.
To facilitate the classroom and workshop integration of three autistic clients, we examined the feasibility of teaching them to respond appropriately without the continual presence of specially trained treatment providers. Within a multiple baseline design, a 4-step treatment process was implemented to promote durable responsive performance. Results indicated that the therapist could be removed from the treatment environment and that appropriate behavior could be successfully maintained in community settings with only infrequent and delayed contingencies.  相似文献   
50.
This project examined psychosocial characteristics of 24 preschool-aged siblings of handicapped children in relation to a control group of 22 siblings of nonhandicapped children. Subjects were matched on family size and income, sibling age, birth order, sex, age spacing, and marital status of their parents. Results indicated no statistically significant differences between groups of children on measures of perceived self-competence and acceptance, understanding of developmental disabilities, empathy, and child care responsibility. Significant group differences were found where brothers of handicapped children were rated by their mothers as being more depressed and aggressive than brothers of nonhandicapped control children. Sisters of handicapped children were rated by mothers as being more aggressive than sisters of nonhandicapped children. Sisters of handicapped children and brothers of nonhandicapped children had significantly fewer privileges and more restrictions on their home activities than other groups. Results are discussed in relation to previous research on older silbings of handicapped children and the general literature on family stress and childhood disability and disease. The importance of examining sibling functioning via multiple measures of child behavior is stressed.The authors are grateful to the children and families who participated in the project. The assistance of Dr. Ricardo Barrera, Christine DiBlasio, Lisa Kaye, Paola Bellabarba, Jeanne Logozzo, Donna Motley, Jennifer Harter, and Tina Meisell is also gratefully acknowleged. This project was funded by Grant Number G008300345 from the U.S. Department of Education.  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