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   20999篇
  免费   417篇
  国内免费   1篇
  21417篇
  2019年   281篇
  2018年   332篇
  2017年   298篇
  2016年   362篇
  2015年   234篇
  2014年   330篇
  2013年   1724篇
  2012年   587篇
  2011年   626篇
  2010年   384篇
  2009年   420篇
  2008年   539篇
  2007年   583篇
  2006年   536篇
  2005年   453篇
  2004年   482篇
  2003年   457篇
  2002年   461篇
  2001年   526篇
  2000年   608篇
  1999年   406篇
  1998年   280篇
  1997年   215篇
  1996年   210篇
  1995年   212篇
  1992年   338篇
  1991年   355篇
  1990年   349篇
  1989年   333篇
  1988年   314篇
  1987年   280篇
  1986年   294篇
  1985年   314篇
  1984年   247篇
  1983年   262篇
  1982年   214篇
  1981年   232篇
  1980年   225篇
  1979年   322篇
  1978年   276篇
  1976年   209篇
  1975年   295篇
  1974年   321篇
  1973年   328篇
  1972年   263篇
  1971年   261篇
  1969年   243篇
  1968年   294篇
  1967年   271篇
  1966年   234篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
John F. Halpin 《Synthese》1986,69(3):325-340
In his (1981) paper, Stalnaker has revised his old theory of conditionals and has given the revision an interesting defense. Indeed, Stalnaker shows that this new theory meets the standard objections put to the old. However, I argue that the revision runs into difficulties in the context of quantum mechanics: If Stalnaker's theory of the conditional is assumed, then from plausible assumptions certain Bell-like conflicts with experiment can be derived. This result, I go on to argue, is a good reason to reject Stalnaker's theory, at least for the quantum mechanical context.I wish to thank Arthur Fine, Paul Teller, Dorothy Grover, and Anil Gupta for their helpful comments and criticisms on earlier drafts of this paper.  相似文献   
112.
Contrast effects were obtained in rats in the consumption of saccharin solutions in three different paradigms. Degree of negative contrast varied as a function of concentration disparity, but not equally in the three procedures. Successive negative contrast occurred following shifts from 0.15% to either 0.075% or 0.05% saccharin but did not occur following shifts to 0.10% or 0.125% saccharin. Some degree of simultaneous contrast was obtained with all four concentration disparities. Anticipatory contrast, where the intake of the first substance is suppressed by a more preferred second substance, occurred only in the case of the 0.05%-0.15% difference in concentrations. It was suggested that the several contrast paradigms engage somewhat different psychological processes differentially involving emotional, sensory, and associative mechanisms, but all lead to behavior based on relative value. A modification of Toates's (1981) incentive model of ingestive behavior was suggested to incorporate relativity effects based on both associative and nonassociative factors in the consumption of both nutritive and nonnutritive substances.  相似文献   
113.
The ability to think of a previously studied item has often been shown to be impaired when, in one way or another, the extraitem context is changed from study to test. In a series of five experiments, such impairment is induced in a somewhat different way. A fragment (e.g. r-i--rop) of a just-studied word (raindrop) is shown to be less readily completed if it is presented bit by bit (r------p, r----r-p, r-i--r-p, r-i--rop) rather than all at once (Experiments 1, 3, 4, and 5). No such effect is found if the word has not been studied beforehand (Experiments 2, 3, 4, and 5). This pattern of results occurs even when fragments of studied and nonstudied words occur in the same test and under conditions in which subjects cannot tell whether a given fragment is of a studied or nonstudied word (Experiments 4 and 5). In addition, for words that have been studied beforehand, the impairment is shown to increase systematically with the number of steps involved in the presentation of the word fragment (Experiment 3) and also to persist when the time allowed for completion of the final version of the fragment is increased from 4 s to a full minute (Experiment 5).  相似文献   
114.
Although single-subject research techniques are relevant and valuable to counselors, analyzing change by graphs alone is open to major sources of error. The author discusses these sources and explores the issues of serial dependency, unreliability of graphs, interjudge disagreement on graphed data, and the use of a more reliable statistical procedure (the time-series statistic) with relevance to the counselor in the field.  相似文献   
115.
The purpose of this study was to provide age-comparative evidence of social cognitive reasoning in adulthood, as mediated by the emotional saliency of tasks tapping postformal reasoning. Specifically, the tasks focused on the ability to resolve discrepant accounts of the same event sequence. It was assumed that less mature thinking may be more evident in reasoning contexts in which emotional factors play a major role. A postformal coding scheme was used to assess levels of reasoning in an interpersonal context. Tasks were administered to 60 subjects--adolescents and young and middle-aged adults. Measures of formal operations, ego level, and verbal ability were also administered. An interaction was found between age and degree of emotional saliency of the task for reasoning level. Specifically, adolescents performed less well on tasks higher in degree of emotional saliency. In addition, developmental differences in postformal reasoning as a function of age and ego level were found.  相似文献   
116.
Fluid intelligence belongs to that cluster of intellectual abilities evincing aging loss. To examine further the range of intellectual reserve available to aging individuals and the question of replicability in a new cultural and laboratory setting, 204 healthy older adults (mean age = 72 years; range = 60-86) participated in a short-term longitudinal training study. For experimental subjects, 10 sessions consisted of cognitive training involving two subability tests (Figural Relations, Induction) of fluid intelligence. The pattern of outcomes replicates and expands on earlier studies. Older adults have the reserve to evince substantial increases in levels of performance in fluid intelligence tests. Transfer of training, however, is narrow in scope. Training also increases accuracy of performance and the ability to solve more difficult test items. Difficulty level was estimated in a separate study, with a comparable sample of N = 112 elderly adults. Future research is suggested to examine whether intellectual reserve extends to near-maximum levels of performance.  相似文献   
117.
RSCORE-J, a computer program for a signal-detection analysis of pooled rating-method data, is listed and described. RSCORE-J computes jackknife estimates of ROC parameters and their standard errors from rating-method data pooled over a group of observers.  相似文献   
118.
This study evaluated the relative efficacy of long (1 minute) and short (15 seconds) durations of negative practice for reducing self-stimulatory leg pounding of a traumatically brain-injured adult. In individual social skill training classes, long negative practice and short negative practice were administered concurrently in an alternating treatments design. Generalization of treatment effects outside of training sessions was assessed during the client's lunch period. The results revealed that both durations of negative practice were equally effective in reducing leg pounding during training sessions. However, the effects of training did not generalize to settings in which the practice contingency was not enforced. Pounding was more frequent and negative practice somewhat less effective during periods of high social stimulation.  相似文献   
119.
Attention, Perception, & Psychophysics - Speech perception abilities are modified by linguistic experience to maximize sensitivity to acoustic contrasts that are important for one’s...  相似文献   
120.
The present study examined some previously reported relationships between drug use by adolescents and perceived attitudes and behaviors of their parents. An anonymous questionnaire was administered to the student body of an inner-city secondary school for difficult students. Relationships between parental use of drugs and adolescent use of the same drugs were moderate and roughly equivalent across drugs. However, parental use of marijuana was strongly related to the adolescent's use of other, harder drugs such as opiates, cocaine, amphetamines, and barbiturates. This finding is explained within the framework of Kandel's postulated stages of drug initiation. It points to a need for further study of parental influences, which may be increasingly problematic as more individuals who have grown up in our marijuana-accepting society become parents of adolescents.  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