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   18876篇
  免费   917篇
  国内免费   15篇
  2021年   157篇
  2020年   262篇
  2019年   273篇
  2018年   396篇
  2017年   425篇
  2016年   416篇
  2015年   316篇
  2014年   348篇
  2013年   1519篇
  2012年   643篇
  2011年   727篇
  2010年   440篇
  2009年   416篇
  2008年   568篇
  2007年   539篇
  2006年   460篇
  2005年   411篇
  2004年   416篇
  2003年   369篇
  2002年   392篇
  2001年   741篇
  2000年   756篇
  1999年   504篇
  1998年   216篇
  1997年   197篇
  1996年   157篇
  1995年   157篇
  1993年   163篇
  1992年   384篇
  1991年   346篇
  1990年   369篇
  1989年   354篇
  1988年   341篇
  1987年   309篇
  1986年   326篇
  1985年   327篇
  1984年   259篇
  1983年   220篇
  1979年   204篇
  1978年   173篇
  1975年   196篇
  1974年   256篇
  1973年   206篇
  1972年   212篇
  1971年   180篇
  1970年   155篇
  1969年   202篇
  1968年   212篇
  1967年   171篇
  1966年   197篇
排序方式: 共有10000条查询结果,搜索用时 120 毫秒
871.
The interrelationship of measures of rigidity-flexibility and of psychometric intelligence is examined. The latent factors of Attitudinal Flexibility, Motor-Cognitive Flexibility, and Psychomotor Speed are derived from the Test of Behavioral Rigidity, and factors of Inductive Reasoning, Spatial Orientation, Verbal Ability, Numeric Ability, Verbal Memory, and Perceptual Speed are derived from the Thurstone Primary Mental Abilities Test and the Educational Testing Service Kit of Factor-Referenced Tests. The data base in this study comes from the fifth wave of the Seattle Longitudinal Study (N = 1,628; age range, 22-95 years). The Rigidity-Flexibility factors were found to be independent of the cognitive domain. Also, longitudinal stability of the factor structure of the rigidity-flexibility domain was confirmed for 837 participants tested in both 1977 and 1984.  相似文献   
872.
Thirty community-dwelling, moderately depressed elderly were randomly assigned to 1 of 3 interventions: experimenter-accompanied exercise in the form of walking, a social contact control condition, and a wait-list control. Exercise and social contact both resulted in significant reductions in both the total and the psychological subscale of the Beck Depression Inventory (BDI). The exercise condition, however, unlike the control conditions, resulted in decreased somatic symptoms of the BDI. These results indicate that, at least in the short term, exercise has a broader effect compared with control conditions in reducing depressive symptoms in the moderately depressed elderly.  相似文献   
873.
The purpose of the current study was to examine the agreement across three informants (youth, teacher, caretaker) when rating behaviors of incarcerated juvenile delinquents. Furthermore, the agreement between a dimensional approach (Child Behavior Checklist) and a categorical approach (DSM-III-R) of assessing behavior was examined. Fifty-two delinquent youth were assessed with a structured interview. In addition, the youth, teacher, and caretaker completed the Child Behavior Checklist (CBCL). The results indicated significant correlations across the teacher and caretaker for externalizing types of problems. The youth report form of the CBCL did not correspond to either adult informant. However, the ratings by the teacher and caretaker were related to externalizing types of problems, primarily hyperactivity/inattention, derived from the structured interview with the delinquent. The results suggest that, in the psychological assessment of incarcerated juvenile delinquents, agreement across informants is dependent on multiple factors, including type of behavior assessed and the approach utilized in assessment.This work was supported, in part, by the Juvenile Justice Coordinating Council of Georgia, the Office of Juvenile Justice and Delinquency Prevention, and the University of Georgia's Institute for Behavioral Research.  相似文献   
874.
When was the last time you saw a job application with no spelling or grammatical errors? Basic skill deficiencies among people at all levels of business are forcing companies to develop innovative ways of compensating for and correcting the problem. What follows is a summary of literacy training strategies and suggestions for implementation.  相似文献   
875.
Psychological investigations of the impact of personality on health behaviours have tended to emphasize fine distinctions among personality variables while failing to distinguish among different kinds of behaviours. For example, theoretical treatments of perceived personal control are quite sophisticated; in contrast, only one well-known analysis of health behaviours exists. We propose four categories of health-enhancing behaviours, which take into account contemporary views of the shift in health care from acute and physician-directed actions to long-term and patient-directed efforts. In addition, we suggest that perceived control (we emphasize locus of control because of its generality and parsimony) is an important predictor variable when combined with other factors common to current models of health behaviour.  相似文献   
876.
877.

A differential conditioning study examined whether an acoustic startle probe, presented during extinction of an aversively conditioned visual stimulus, potentiated the reflex eyeblink response in humans and whether this potentiation varied with the change in affective valence of the conditioned stimulus. Sixty college students were randomly assigned to view a series of two slides, depicting either unpleasant/highly arousing, unpleasant/moderate arousing, neutral/calm, pleasant/moderate arousing or pleasant/highly arousing scenes and objects (duration: 8 sec). During preconditioning (8 trials) and extinction (24 trials) acoustic startle probes (white noise bursts [50 ms; 95 dBA] were administered during and between slide presentation). During acquisition (16 trials) CS+ was reinforced by an electric shock. Startle response magnitudes significantly increased from preconditioning to extinction and were substantially larger to CS+. Conditioned startle reflex augmentation linearly increased with the pleasantness of the slides. Furthermore, subjects showed a greater post-conditioning increase of judged aversiveness to slides that they had previously reported to be more pleasant, exactly paralleling the startle reflex results.

  相似文献   
878.
Many perceptual categories exhibit internal structure in which category prototypes play an important role. In the four experiments reported here, the internal structure of phonetic categories was explored in studies involving adults, infants, and monkeys. In Experiment 1, adults rated the category goodness of 64 variants of the vowel /i/ on a scale from 1 to 7. The results showed that there was a certain location in vowel space where listeners rated the /i/ vowels as best instances, or prototypes. The perceived goodness of Iii vowels declined systematically as stimuli were further removed from the prototypic Iii vowel. Experiment 2 went beyond this initial demonstration and examined the effect of speech prototypes on perception. Either the prototypic or a nonprototypic IM vowel was used as the referent stimulus and adults’ generalization to other members of the category was examined. Results showed that the typicality of the speech stimulus strongly affected perception. When the prototype of the category served as the referent vowel, there was significantly greater generalization to other /i/ vowels, relative to the situation in which the nonprototype served as the referent. The notion of aperceptual magnet was introduced. The prototype of the category functioned like a perceptual magnet for other category members; it assimilated neighboring stimuli, effectively pulling them toward the prototype. In Experiment 3, the ontogenetic origins of the perceptual magnet effect were explored by testing 6-month-old infants. The results showed that infants’ perception of vowels was also strongly affected by speech prototypes. Infants showed significantly greater generalization when the prototype of the vowel category served as the referent; moreover, their responses were highly correlated with those of adults. In Experiment 4, Rhesus monkeys were tested to examine whether or not the prototype’s magnet effect was unique to humans. The animals did not provide any evidence of speech prototypes; they did not exhibit the magnet effect. It is suggested that the internal organization of phonetic categories around prototypic members is an ontogenetically early, species-specific, aspect of the speech code  相似文献   
879.
The acquisition of observing.   总被引:6,自引:6,他引:0       下载免费PDF全文
Pigeons were exposed to stimuli correlated with the presence or absence of a variable-interval 60-second schedule of reinforcement only while they depressed a crossbar or "perch." In the first experiment, the stimuli were different tilts of a line displayed on the key. When the difference in brightness between the line and the background (salience) was maximal, seven of eight birds acquired the discrimination, but when the difference was reduced by 50%, only one succeeded. In the second experiment, wavelength of chamber illumination served as the relevant dimension. Neither experiment showed a large effect attributable to the magnitude of the difference (disparity) between the positive and the negative stimulus. Individual differences in time spent observing were positively correlated with level of discrimination in the presence of the stimuli. All birds produced the positive stimulus for a greater proportion of the available time than they did the negative stimulus. This may be the mechanism that provides selective reinforcement of observing. Finally, the formation of a discrimination was analyzed in terms of changes in the proportion of time spent in contact with the discriminative stimuli.  相似文献   
880.
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