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   37171篇
  免费   1448篇
  国内免费   16篇
  38635篇
  2020年   427篇
  2019年   538篇
  2018年   719篇
  2017年   788篇
  2016年   797篇
  2015年   553篇
  2014年   680篇
  2013年   2892篇
  2012年   1243篇
  2011年   1235篇
  2010年   804篇
  2009年   759篇
  2008年   1111篇
  2007年   1124篇
  2006年   1001篇
  2005年   885篇
  2004年   830篇
  2003年   784篇
  2002年   802篇
  2001年   1153篇
  2000年   1107篇
  1999年   860篇
  1998年   372篇
  1997年   370篇
  1995年   349篇
  1993年   341篇
  1992年   730篇
  1991年   640篇
  1990年   696篇
  1989年   601篇
  1988年   635篇
  1987年   592篇
  1986年   601篇
  1985年   539篇
  1984年   498篇
  1983年   477篇
  1982年   342篇
  1979年   565篇
  1978年   394篇
  1977年   339篇
  1975年   448篇
  1974年   491篇
  1973年   527篇
  1972年   394篇
  1971年   386篇
  1970年   348篇
  1969年   400篇
  1968年   470篇
  1967年   428篇
  1966年   353篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Selective attention was studied when subjects were required to make either speeded classifications of single stimuli or comparisons of pairs of multidimensional stimuli. Experiment 1 established that subjects were able to attend selectively to form when the irrelevant dimension of size or shading varied in a speeded-classification (card-sorting) task. Experiment 2 confirmed this finding in a discrete-trials task. However, subjects werenot able to filter out irrelevant dimensional disparity in a comparably designed simultaneous-comparison (i.e., “same”-“different”) task. Mean “same” reaction time increased monotonically with increases in disparity between the two stimuli on the irrelevant dimension. Experiment 3 also revealed a monotonie increase in “same” RT as a function of irrelevant disparity in a successive-comparison task. These results were discussed in terms of a normalization model proposed by Dixon and Just (1978) in which it is assumed that a subject equates the two stimuli on the irrelevant dimension before deciding that they are the same along the relevant dimension. It was concluded that: (1) although subjects can efficiently filter out irrelevant disparity in a speeded-classification task, interference due to irrelevant disparity is obtained in the comparison tasks, (2) a common process such as normalization does not necessarily underlie performance in the speeded-classification and comparison tasks, (3) the ability to attend selectively to a stimulus dimension may be task determined as well as stimulus determined, and (4) contrary to the Dixon and Just proposal, normalization of irrelevant disparity occurs in a comparison task, even when the relevant dimension is represented as a separate encoding feature.  相似文献   
992.
993.
It was proposed that people attribute an individual's behavior more to internal factors when that individual's actions are influenced by reward than when those actions are influenced by punishment. Previous research has failed to control for the power of reward versus punishment which, in effect, creates a confounding of behavioral base rates (consensus) with the reward-punishment manipulation. The current research created reward and punishment contingencies that were equal in their base rates for producing a compliant response. In Experiment 1, subjects (n = 63) who produced the base-rate data also made attributions regarding a compliant target person. The results supported the reward-punishment attributional asymmetry hypothesis in that the target person was held more responsible for his actions in the reward than in the punishment conditions. A second experiment (n = 72) provided some attributors with information regarding base rates for compliance and measured perceived base rates for compliance. Knowledge of the base rates for compliance eliminated the reward-punishment attributional asymmetry phenomenon. Subjects not provided with such knowledge erroneously assumed different base rates for reward and punishment and maintained the perception of reward-punishment attributional asymmetry. Using subjects' estimates of base rate for compliance as a covariate eliminated the attributional asymmetry effect. It is suggested that erroneous base-rate assumptions mediate the attributional asymmetry phenomenon.  相似文献   
994.
Experiments 1 and 2 examined the effects of various durations of lickcontingent delays of reinforcement on the development of schedule-induced polydipsia. Food was provided every 1 min in the absence of licking. Delays of 1 min or more effectively disrupted the development of the licking behavior. In Experiments 3 and 4 a lick-contingent stimulus was provided in addition to the delay of food delivery. A light, which was turned on by a lick and turned off by food, greatly enhanced the development of polydipsia under delays that had previously prevented such development. A tone proved less effective than the light in promoting the development of polydipsia. Adventitious reinforcement and conditioned punishment explanations of these results were considered. A distinction was drawn between the mechanism responsible for the development of schedule-induced behavior and that responsible for its maintenance.  相似文献   
995.
This study examined the questions of whether employment and educational tests demonstrate either differential validity or test unfairness to Hispanic Americans relative to the majority group. Relevant data from 19 published and unpublished studies formed the basis of the review and analysis. Results for employment tests, based on a very large amount of data, indicated that differential validity occurs no more frequently than would be expected on the basis of chance plus the operation of various statistical artifacts. The frequencies of slope and intercept differences between Hispanic and majority regressions were also within the chance range. A similar pattern of results obtained for the more limited amount of data available on educational tests. Taken together, the results provide strong evidence that tests are neither differentially valid for, nor unfair to, Hispanics. These findings are consistent with the results of previous studies of test validity and fairness for blacks.  相似文献   
996.
In three cued recall experiments, extralist retrieval cues that were congruous in meaning to an encoded target pair of words produced better recall of the targets than wh6n the cuetarget relation was incongruous. However, this result, which differs from that of other experiments, depended in some cases on scoring recall of a target pair when either member of the pair was recalled. It is argued that (1) pairs of words are typically stored as higher order units, (2) the best test procedure is to request recall of both members of the pair when an extralist cue is presented, and (3) semantic features provide an important dimension in the mnemonic representation of word events.  相似文献   
997.
One possibility suggested by the literature for maximizing the efficiency of behavior modification procedures concerns the relationship between target behaviors and their reinforcers. Therefore, in this experiment three severely autistic children were taught a total of six new target behaviors (in a multiple baseline design) employing two different response-reinforcer relationships: (1) those where the target behaviors were a direct part of the response chain required to procure a reinforcer (e.g., opening the lid of a container to obtain a food reward inside the container); and (2) those where the target behavior was an indirect part of the chain leading to the reinforcer (e.g., the therapist handing the child a food reward after the child had opened the lid of an empty container). In all cases, the results showed rapid acquisition only when the target behavior was a direct part of the chain leading to the reinforcer. The results are discussed in terms of several possible conceptualizations concerning efficient reinforcement contingencies, and in terms of their implications for teaching autistic children.This investigation was supported by U.S. Public Health Service Research Grants MH 28210 and MH 28231, and by U.S. Office of Education Research Grant G007802084 from the Bureau for the Education of the Handicapped. Portions of the results described in this article were discussed in a presentation at the 13th Annual AABT Convention in San Francisco, 1979. The authors are particularly grateful to Andrew Egel, Roberta Elman, Janis Costello, and Karen Britten, for their helpful comments, and to Jody Fisher and Gina Richman, for their assitance in the data collection.  相似文献   
998.
Selective attention to visual and auditory stimuli and reflection-impulsivity were studied in normal and learning-disabled 8- and 12-year-old boys. Multivariate analyses, followed by univariate and paired-comparison tests, indicated that the normal children increased in selective attention efficiency with age to both visual and auditory stimuli. Learning-disabled children increased in selective attention efficiency with age to auditory, but not to visual, stimuli. Both groups increased with age in reflection as measured by Kagan's Matching Familiar Figures Test (MFF). The 8-year-old learning-disabled children were more impulsive than the 8-year-old normals on MFF error scores, but not on MFF latency scores. No difference occurred between the 12-year-old learning-disabled and normal children on either MFF error or MFF latency scores. Correlations between the selective attention scores and MFF error and latency scores were not significant.This research was supported in part by BEH grant G007507227. The authors are indebted to Eleanor McCandless for her assistance in securing the learning-disabled subjects and to James McLeskey and Michael Popkin for their assistance in collecting and analyzing data.  相似文献   
999.
A distinction between compound and coordinate bilingualism has been employed to conceptualize linguistic organization in bilinguals. Compound bilinguals are those who acquired their languages in a joint context and therefore are presumed to store linguistic information interdependently. Coordinates include those who acquired their languages in separate contexts and therefore are presumed to maintain independent linguistic stores. To study the usefulness of this distinction, Spanish-English and English-Spanish, compound, and coordinate bilinguals were asked to give intra-and interlingual free and restricted word associations to equivalent English and Spanish stimuli for which the responses of monolingual speakers were not equivalent. As predicted, compound bilinguals gave significantly more equivalent responses and responded significantly faster than did coordinates. However, since these differences were only modest in size, they cannot be interpreted as supporting the usefulness of the compound-coordinate distinction. None of the predictions regarding the effect of proficiency on performance were supported. Differences as a function of native language, type of association task, and association conditions were obtained and are discussed.This research was supported by USPHS Grant HD 01368 to Dr. Klaus Riegel, University of Michigan, and was included as one portion of a doctoral dissertation submitted by the author to the Horace H. Rackham School of Graduate Studies at the University of Michigan.  相似文献   
1000.
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