全文获取类型
收费全文 | 12772篇 |
免费 | 1210篇 |
国内免费 | 868篇 |
专业分类
14850篇 |
出版年
2024年 | 59篇 |
2023年 | 294篇 |
2022年 | 227篇 |
2021年 | 311篇 |
2020年 | 648篇 |
2019年 | 660篇 |
2018年 | 583篇 |
2017年 | 672篇 |
2016年 | 605篇 |
2015年 | 432篇 |
2014年 | 547篇 |
2013年 | 1856篇 |
2012年 | 344篇 |
2011年 | 495篇 |
2010年 | 359篇 |
2009年 | 513篇 |
2008年 | 614篇 |
2007年 | 618篇 |
2006年 | 585篇 |
2005年 | 548篇 |
2004年 | 469篇 |
2003年 | 373篇 |
2002年 | 318篇 |
2001年 | 255篇 |
2000年 | 188篇 |
1999年 | 207篇 |
1998年 | 169篇 |
1997年 | 144篇 |
1996年 | 107篇 |
1995年 | 129篇 |
1994年 | 88篇 |
1993年 | 73篇 |
1992年 | 72篇 |
1991年 | 34篇 |
1990年 | 35篇 |
1989年 | 39篇 |
1988年 | 36篇 |
1987年 | 32篇 |
1985年 | 151篇 |
1984年 | 142篇 |
1983年 | 117篇 |
1982年 | 100篇 |
1981年 | 78篇 |
1980年 | 97篇 |
1979年 | 81篇 |
1978年 | 110篇 |
1977年 | 72篇 |
1976年 | 60篇 |
1975年 | 34篇 |
1973年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
21.
S.Stavros Valenti 《Journal of experimental child psychology》1985,40(3):406-419
Data relating novelty preference to age for normal children are inconsistent, although a current theory predicts a developmental shift from novelty to familiarity preference in selective learning (D. Zeaman, 1976, in T. J. Tighe & R. N. Leaton (Eds.), Habituation: Perspectives from child development, animal behavior, and neurophysiology (pp. 297–320), Hillsdale, NJ: Erlbaum). Support for this theory, however, has been derived primarily from studies of retardate learning. Normal children's novelty preference was examined within a modified Moss-Harlow (E. Moss & H. F. Harlow, 1947, Journal of Comparative and Physiological Psychology, 40, 333–342) design to compare Zeaman's model with that of S. L. Witryol and W. Wanich (1983, The Journal of Genetic Psychology, 143, 3–8). Each of 16 problems, consisting of three single-stimulus demonstration trials and one two-choice test, was administered to 180 children (mean CA 4, 5.5, and 7 years) in three reward conditions. Novelty was manipulated by varying stimulus familiarization in the demonstration trials. Experiment 1 showed strong preferences for novel over familiar (demonstrated) stimuli at each age. Experiment 2 revealed novelty preference across age levels, two levels of reward contrast, and two levels of task difficulty. It was reasoned that Moss-Harlow tasks designed for normal children typically present a much higher level of difficulty than that intended by researchers. Furthermore, developmental decreases in novelty preference by retardates may derive from (a) transfer of training from prior experiments and (b) specific, repetitive instructions which may have directed attention away from stimulus novelty. 相似文献
22.
The pathological left-handedness syndrome 总被引:3,自引:0,他引:3
A clinical syndrome of pathological left-handedness (PLH) is proposed to identify the pattern of correlative changes in lateral development associated with early brain injury in some manifest left-handers. This syndrome is believed to be caused by a hemispheric lesion that is predominantly left-sided (or bilateral asymmetric), which onsets before Age 6, and which encroaches upon the critical speech zones of the frontotemporal/frontoparietal cortex. The pattern of changes may include any or all of the following features: shifts in manual dominance, trophic changes in the extremities, transfer of hemispheric speech, and/or intrahemispheric reorganization of visuospatial cognitive functions. Although some of these correlates of PLH have long been known, they have not been recognized as an interrelated pattern of traits that constitute a clinical syndrome. Identification of these individuals, all manifest left-handers, will be shown to have implications for diagnosis/remediation and for models of recovery of function. 相似文献
23.
Classmate likeability, compromising skill, and temperament (n = 135) and after-school patterns of social interaction (n = 101) were examined for third through seventh grade children who were identified by a binomial probability model as popular, rejected, neglected, or average in the classroom setting. Significant effects were obtained for each type of score. Compared to the other social status groups, popular children were the best liked and rejected children were the least liked; neglected and average children fell between these two extremes. Popular children had higher compromising scores than either rejected or average children, and neglected children had higher scores than rejected children. Compared to average children, rejected children had higher attention and rhythmicity temperament scores. Finally, popular and average children had more neighborhood friends than either rejected or average children, and meglected children had more younger neighborhood friends than did average children. Results are discussed in terms of models of peer social status. 相似文献
24.
Results are presented for the 1st analysis of the relationship between IQ and completed fertility using a large, representative sample of the US population. Correlations are predominantly negative for cohorts born between 1894 and 1964 but are significantly more positive for cohorts whose fertility was concentrated in the baby boom years. Previous studies reporting slightly positive correlations appear to have been biased in their restriction of samples to atypical cohorts. The National Opinion Research Center (NORC), a nonprofit research organization affiliated with the University of Chicago, conducted the General Social Survey (GSS) in the US each year from 1972 to 1982, except for 1979. A combination of block quota and full probability sampling was employed. Hour-long interviews were completed with 12,120 respondents who were English-speaking, noninstitutionalized adults (18 years or older) living within the continental US. Such questions as age, place of birth, income and occupation, were asked in each interview. Other questions about attitudes on various social, political, and moral issues were rotated in different years. The unique opportunity this data set affords is an overview of the relationship between intelligence and fertility for a nationally representative sample of Americans whose major reproductive years fell between 1912 and 1982. Data were consolidated from the 4 surveys in which the vocabulary test was given (1974, 1976, 1978, and 1982). Respondents were divided into 15 birth cohorts of 5-year intervals ranging from before 1894 to 1964. Correlations between vocabulary scores and number of siblings are markedly negative across all 15 cohorts. Vocabulary sibling correlations are more negative in every cohort than vocabulary offspring correlations. Previous reports of a neutral or slightly eugenic relationship appear to be due to the nature of the samples used, in part because the cohorts chosen were atypical, and in part because they did not include nonwhites. Childless respondents averaged slightly higher scores than did those with 1 or more children, indicating that the automatic exclusion of the childless from sibling-IQ studies has not spuriously inflated negative correlations. 相似文献
25.
26.
27.
Statistical consistency and hypothesis testing for nonmetric multidimensional scaling 总被引:1,自引:0,他引:1
Henry E. Brady 《Psychometrika》1985,50(4):509-537
The properties of nonmetric multidimensional scaling (NMDS) are explored by specifying statistical models, proving statistical consistency, and developing hypothesis testing procedures. Statistical models with errors in the dependent and independent variables are described for quantitative and qualitative data. For these models, statistical consistency often depends crucially upon how error enters the model and how data are collected and summarized (e.g., by means, medians, or rank statistics). A maximum likelihood estimator for NMDS is developed, and its relationship to the standard Shepard-Kruskal estimation method is described. This maximum likelihood framework is used to develop a method for testing the overall fit of the model. 相似文献
28.
Previous publications emanating from the Colorado Adoption Project have reported significant relationships between parental general cognitive ability (g) and infant Bayley MDI scores. The present study compared infant Bayley factor scores representing separable dimensions of infant cognition with parental general and specific cognitive abilities for 182 adoptive families and 164 nonadoptive families. Parent/offspring correlations between 12-month Bayley factors and parental cognitive abilities suggest only minimal relationships for both parental g and specific abilities. At 24 months, more parent/offspring resemblance was present; moreover, Bayley factors that were related to parental cognition tended to be related to parental g, not to specific abilities. The finding of significant parent/offspring relationships at 24 months between biological parents and their adopted-away infants, as well as between nonadoptive parents and their infants, suggests some genetic continuity from infancy to adulthood. 相似文献
29.
Subcortical functions in language: A working model 总被引:9,自引:1,他引:8
Bruce Crosson 《Brain and language》1985,25(2):257-292
The current paper explains a model of subcortical language functions that focuses on dynamic interactions between the cortex, the thalamus, and the basal ganglia in the production of spoken language. The model was derived from (a) studies of subcortical lesions and language, (b) studies of subcortical stimulation and language, (c) knowledge regarding neural pathways between various cortical and subcortical structures, and (d) indications that preverbal monitoring of language occurs. In the current model, the thalamus plays roles in cortical arousal and activation and in preverbal semantic monitoring. The basal ganglia function to regulate the degree of excitation conveyed from the thalamus to the cortex and to time the release of formulated language for motor programming. Consistency with classical syndromes of aphasia and potential applications to other areas in the neurosciences are discussed. The current theory, unlike previous formulations, is specific enough that testable hypotheses can be derived. 相似文献
30.
Jordi Peña-Casanova Teresa Roig-Rovira Amalia Bermudez Eduard Tolosa-Sarro 《Brain and language》1985,26(1):63-71
A 47-year-old man with a left temporo-occipital infarct in the area of the posterior cerebral artery is presented. The neuropsychological examination did not reveal aphasia or gross mental deficits. The patient presented with alexia without agraphia, color agnosia, but few visual perceptual deficits. The main impairment was in confrontation naming; he was incapable of naming objects and pictures, not from lack of recognition (excluding visual agnosia) but from lack of access to the appropriate word (optic aphasia). The patient also exhibited a deficit in the evocation of gesture from the visual presentation of an object (optic apraxia) and a difficulty in "conjuring up" visual images of objects (impaired visual imagery) and loss of dreams. The fundamental deficit of this patient is tentatively explained in terms of visuoverbal and visuogestural disconnection and a deficit of mental imagery. 相似文献