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861.
In two experiments we examined factors that contribute to retarded emergence of conditioned responding to a conditioned stimulus (CS) trained in a context in which unsignaled unconditioned stimuli (USs) had previously been administered. In both experiments water-deprived rats were used in a conditioned lick suppression task to measure the conditioned response elicitation potential of the CS and the training context. From Experiment 1 we determined that nonreinforced exposure to the excitatory context after US preexposure and prior to CS-US pairings in that context eliminated the conditioned response deficit observed on a subsequent test of the CS. The recovery from the US preexposure deficit was nearly as great in animals that received nonreinforced exposure to the excitatory training context after the CS-US pairings but prior to the ultimate test of the CS. From Experiment 2 we determined that the recovery induced by contextual deflation after CS training was specific to deflation of the context in which the CS was trained as opposed to another excitatory context. In total, these experiments suggest that context-US associations partially mask the expression of a learned CS-US association. These results are discussed in terms of recent models of conditioned response generation.  相似文献   
862.
In the present research water-deprived rats were used in a conditioned lick suppression paradigm to test and further develop Rescorla's (1968) contingency theory, which posits that excitatory associations are formed when a conditioned stimulus (CS) signals an increase in unconditioned stimulus (US) likelihood and that inhibitory associations develop when the CS signals a decrease in US likelihood. In Experiment 1 we found that responding to a CS varied inversely with the associative status of the context in which the CS was trained and that this response was unaltered when testing occurred in a distinctively dissimilar context with a different conditioning history, provided associative summation with the test context was minimized. These results suggest that manifest excitatory and inhibitory conditioned responding is modulated by the associative value of the training context rather than that of the test context. In Experiment 2 it was demonstrated that postconditioning decreases in the associative value of the CS training context reduced the effective inhibitory value of the CS even when testing occurred outside of the training context. Moreover, this contextual deflation effect was specific to the CS training context as opposed to any other excitatory context. Collectively, these studies support the comparator hypothesis, which states that conditioned responding is determined by a comparison of the associative strengths of the CS and its training context that occurs at the time of testing rather than at the time of conditioning. This implies that all associations are excitatory and that responding indicative of conditioned inhibition reflects a CS-US association that is below (or near) the associative strength of its comparator stimulus. It is suggested that response rules which go beyond a monotonic relation between associative value and response strength can partially relieve learning theories of their explanatory burdens, thereby allowing for simpler models of acquisition.  相似文献   
863.
Computerphobia     
Five studies of over 450 university students presented a comprehensive picture of computer-phobia. Three research and clinically based self-report instruments were developed to measure three nearly independent dimensions of computerphobia-computer anxiety, computer attitudes, and computer cognitions and feelings. Results indicated that older students were more computer anxious, but did not have more negative attitudes, cognitions, or feelings, than did younger students. Women had more negative attitudes than did men. Feminine-identity students showed more anxiety and negative attitudes than did masculine-identity students, regardless of gender. White students had more anxiety and more positive attitudes than did nonwhite students. Computerphobia was related to other anxiety measures (mathematics, state, and trait), but was a separate construct. Experience with computer interaction did not reduce anxiety or improve attitudes. Finally, regardless of academic major, computer-anxious students showed less computer aptitude, literacy, and interest. Implications for treating computerphobia are discussed.  相似文献   
864.
The program development and first-year results of a 3-year U.S. Department of Education Fund for the Improvement of Postsecondary Education (FIPSE) grant are described. The identification of computerphobics and the types of discomfort they experience are defined. A clinically based 5-week model computerphobia reduction and skills-acquisition program is presented. Screening and assessment measures are outlined and three treatment modules—two individual treatments (systematic desensitization and thought stopping) and an information/support group—are described. The first-year results demonstrate significant pretreatment-to-posttreatment change in anxiety, attitudes, cognitions, and feelings. Plans are discussed for further evaluation and program expansion.  相似文献   
865.
J L Miller  P W Jusczyk 《Cognition》1989,33(1-2):111-137
One of the most highly developed human abilities is communication by speech. Throughout the years, research on speech perception has demonstrated that humans are well adapted to extract highly encoded linguistic information from the speech signal. The sophisticated nature of these capacities and their early appearance during development suggest the existence of a rich biological substrate for speech perception. In the present paper, we describe some of these important capacities and examine research from different domains that may help illuminate the nature of their biological foundations.  相似文献   
866.
Assessment of adolescents' learned helplessness in achievement situations   总被引:1,自引:0,他引:1  
Three studies are reported that describe the development, reliability, and initial validation of the Mastery Orientation Inventory (MOI; Reynolds & Miller, in press) as a measure of generalized learned helplessness in adolescents. In Study 1, an initial version of 50 items was administered to a sample of 112 adolescents. A revised 40-item scale with an internal consistency reliability of .94 was then constructed, which correlated significantly with measures of locus of control and depression. Study 2 involved the administration of the 40-item MOI to 645 adolescents. In this study, the reliability of the MOI was .92, and MOI scores were significantly correlated with subjects' depression scores and with self-reported grade point average. Factor analysis of the MOI items produced a strong first factor with high loadings for every item. In Study 3, the 112 subjects who participated in Study 1 were, 3 months later, readministered the MOI, locus of control, and depression measures. As an external criterion variable, 13 teachers provided global ratings of learned helpless/mastery-oriented behaviors for 99 of these subjects. The MOI demonstrated high internal consistency (r alpha = .95) and adequate test-retest (rtt = .77) reliability. Validity was supported by significant correlations between the MOI and the three criterion variables (/rs/ = .49-.58). The results of these investigations provide initial support for the reliability and validity of the MOI as a measure of learned helplessness.  相似文献   
867.
The control of attention by abrupt visual onsets and offsets   总被引:1,自引:0,他引:1  
A letter can be presented visually either by the abrupt appearance of lines that make up the letter (onset transient) or by the abrupt disappearance of extra lines from a form in which the letter is embedded (offset transient). Recent evidence from visual-search tasks has suggested that onset transients have absolute priority over offset transients with respect to the allocation of visual attention. Specifically, these studies have found that a single onset-transient target letter pops out of a background of offset-transient distractor letters (i.e., time to detect the target is independent of the number of distractors), which indicates that attention is automatically directed to the location of an onset-transient stimulus even when there are competing offset transients (Yantis & Jonides, 1984). Because of the way the offset letters were created, however, the total display change (number of offset line-segments plus number of onset line-segments) was greater for onset than for offset letters. Thus, onset targets might have popped out because they produced greater overall display changes rather than because they were the only letters with onset transients. In the present study, a figure that included more offset-transient line segments in the offset-transient letters was used. Under these conditions, onset-transient targets did not pop out of a background of offset-transient distractors. It is suggested that visual attention may be influenced by total display change and, therefore, that onset transients are not necessarily sufficient to control attention when there are many competing offset transients.  相似文献   
868.
Effect of speaking rate on the perceptual structure of a phonetic category   总被引:1,自引:0,他引:1  
When listeners process temporal properties of speech that convey information about the phonetic segments of the language, they do so in a rate-dependent manner. This is seen as a shift in the location of the phonetic category boundary along a temporal continuum toward longer values of the acoustic property in question, as speech is slowed. In a series of experiments, we found that the adjustment for rate is not confined to the region of the category boundary, but extends throughout the phonetic category. Specifically, a change in rate modified the range of stimuli identified as members of a phonetic category, as well as which stimuli were overtly judged to be good exemplars of the category. These findings suggest that the listener's adjustment for speaking rate entails a comprehensive perceptual remapping between acoustic signal and phonetic structure.  相似文献   
869.
A sample of 120 children (69 boys and 51 girls), ranging in age from 9 to 14 yr., was administered the Harter Self-perception Profile for Children before and after a 5-wk. program of swimming instruction. It is predicted that children who improve most in swimming will also have the largest gains in athletic self-concept. The data supported the prediction for an association between gains in swimming skill and self-concept for certain skill groups.  相似文献   
870.
Scores on the "Your Characteristics" section of the Strong-Campbell Interest Inventory (SCII) of 178 high school students (80 boys, 98 girls) were analyzed to determine if what we know about adolescents' self-esteem will predict scores. These adolescents obtained means similar to those of average adults. Implications for counselors are noted.  相似文献   
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