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   1879篇
  免费   102篇
  2023年   14篇
  2021年   11篇
  2020年   32篇
  2019年   52篇
  2018年   65篇
  2017年   58篇
  2016年   53篇
  2015年   53篇
  2014年   63篇
  2013年   226篇
  2012年   112篇
  2011年   113篇
  2010年   48篇
  2009年   59篇
  2008年   81篇
  2007年   88篇
  2006年   80篇
  2005年   67篇
  2004年   75篇
  2003年   62篇
  2002年   61篇
  2001年   27篇
  2000年   22篇
  1999年   35篇
  1998年   26篇
  1997年   18篇
  1996年   16篇
  1995年   11篇
  1994年   12篇
  1993年   14篇
  1992年   16篇
  1991年   15篇
  1990年   15篇
  1989年   11篇
  1988年   16篇
  1987年   16篇
  1986年   16篇
  1985年   11篇
  1984年   12篇
  1983年   19篇
  1982年   22篇
  1981年   12篇
  1979年   14篇
  1978年   10篇
  1977年   13篇
  1976年   10篇
  1975年   10篇
  1974年   9篇
  1973年   12篇
  1968年   9篇
排序方式: 共有1981条查询结果,搜索用时 15 毫秒
61.
Three experiments examined how needs for acceptance might constrain low versus high self-esteem people's capacity to protect their relationships in the face of difficulties. The authors led participants to believe that their partner perceived a problem in their relationship. They then measured perceptions of the partner's acceptance, partner enhancement, and closeness. Low but not high self-esteem participants read too much into problems, seeing them as a sign that their partner's affections and commitment might be waning. They then derogated their partner and reduced closeness. Being less sensitive to rejection, however, high self-esteem participants affirmed their partner in the face of threat. Ironically, chronic needs for acceptance may result in low self-esteem people seeing signs of rejection where none exist, needlessly weakening attachments.  相似文献   
62.
We used fMRI to examine patterns of brain recruitment in 22 healthy seniors, half of whom had selective comprehension difficulty for grammatically complex sentences. We found significantly reduced recruitment of left posterolateral temporal [Brodmann area (BA) 22/21] and left inferior frontal (BA 44/6) cortex in poor comprehenders compared to the healthy seniors with good sentence comprehension, cortical regions previously associated with language comprehension and verbal working memory, respectively. The poor comprehenders demonstrated increased activation of left prefrontal (BA 9/46), right dorsal inferior frontal (BA 44/6), and left posterior cingulate (BA 31/23) cortices for the grammatically simpler sentences that they understood. We hypothesize that these brain regions support an alternate, nongrammatical strategy for processing complex configurations of symbolic information. Moreover, these observations emphasize the crucial role of the left perisylvian network for grammatically guided sentence processing in subjects with good comprehension.  相似文献   
63.
This study aimed to test the hypothesis that impairments of temporal duration processing after frontal lobe lesions reflect deficits in executive monitoring functions rather than a domain-specific deficit in the maintenance of duration information in working memory. Patients with frontodorsal lesions, clinical controls with post-central lesions, and healthy controls performed recognition and classification tasks, which should allow for testing maintenance and monitoring functions, respectively. Results showed mild non-selective impairments of the frontal patients on both temporal and spatial recognition tasks, but a marked selective degradation on temporal classification while performance on spatial classification was unimpaired. This suggests that maintenance of duration information in working memory after frontal lesions is basically preserved but that, depending on executive task characteristics, there is a specific deficit in the strategic organization of this type of information.  相似文献   
64.
Priming visual face-processing mechanisms: electrophysiological evidence   总被引:4,自引:0,他引:4  
Accumulated evidence from electrophysiology and neuroimaging suggests that face perception involves extrastriate visual mechanisms specialized in processing physiognomic features and building a perceptual representation that is categorically distinct and can be identified by face-recognition units. In the present experiment, we recorded event-related brain potentials in order to explore possible contextual influences on the activity of this perceptual mechanism. Subjects were first exposed to pairs of small shapes, which did not elicit any face-specific brain activity. The same stimuli, however, elicited face-specific brain activity after subjects saw them embedded in schematic faces, which probably primed the subjects to interpret the shapes as schematic eyes. No face-specific activity was observed when objects rather than faces were used to form the context. We conclude that the activity of face-specific extrastriate perceptual mechanisms can be modulated by contextual constraints that determine the significance of the visual input.  相似文献   
65.
The behavior of children diagnosed with attention deficit hyperactivity disorder (ADHD) has been hypothesized to be the result of decreased sensitivity to consequences compared to typical children. The present study examined sensitivity to reinforcement in 2 boys diagnosed with ADHD using the matching law to provide more precise and quantitative measurement of this construct. This experiment also evaluated the effects of methylphenidate (MPH) on sensitivity to reinforcement of children with ADHD. Subjects completed math problems to earn tokens under four different variable-interval (VI) schedules of reinforcement presented in random order under both medicated and nonmedicated conditions. Results showed that, in the medicated condition, the matching functions for both subjects resulted in higher asymptotic values, indicating an overall elevation of behavior rate under these conditions. The variance accounted for by the matching law was also higher under the medicated conditions, suggesting that their behavior more closely tracked the changing rates of reinforcement while taking MPH compared to placebo. Under medicated conditions, the reinforcing efficacy of response-contingent tokens decreased. Results are discussed with respect to quantifying behavioral changes and the extent to which the drug interacts with prevailing contingencies (i.e., schedule values) to influence behavioral variability.  相似文献   
66.
Tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) have been associated with an increase in cardiovascular disorders, especially in depressed patients who have pre-existing cardiac disease. These disorders are less likely to occur when a therapeutic dosage is administered. Injuries because of falls are more likely in elderly depressed patients, and orthostatic hypotension occurs with the use of TCAs. Selective serotonin reuptake inhibitor (SSRI) antidepressants differ structurally and in side effects from TCAs and MAOIs. They appear to be effective for treatment of depression, and their side-effect profiles appear safer than those of earlier approved antidepressants used by depressed patients with cardiovascular disorders.  相似文献   
67.
The course, antecedents, and implications for social development of effortful control were examined in this comprehensive longitudinal study. Behavioral multitask batteries and parental ratings assessed effortful control at 22 and 33 months (N = 106). Effortful control functions encompassed delaying, slowing down motor activity, suppressing/initiating activity to signal, effortful attention, and lowering voice. Between 22 and 33 months, effortful control improved considerably, its coherence increased, it was stable, and it was higher for girls. Behavioral and parent-rated measures converged. Children's focused attention at 9 months, mothers' responsiveness at 22 months, and mothers' self-reported socialization level all predicted children's greater effortful control. Effortful control had implications for concurrent social development. Greater effortful control at 22 months was linked to more regulated anger, and at 33 months, to more regulated anger and joy and to stronger restraint.  相似文献   
68.
Recent experimental work is cited which has implications for basic equipment design. Some unsatisfactory earlier innovations are also briefly discussed.

The traditional pad and bell apparatus is not superseded but commonly exhibits defects and hazards for which the recessed electrode principle is introduced as a solution. New high-sensitivity requirements in circuitry to match the recessed electrode pad are met in an unusual and inexpensive way.  相似文献   

69.
Relations between adult anxiety and mood disorders and retrospective reports of excessive childhood shyness were investigated in the US National Comorbidity, Survey (n=5877). Results indicated that 26% of women and 19% of men described themselves as 'very shy' when they were growing up. Of these shy individuals, 53% of women and 40% of men met criteria for a lifetime diagnosis of one or more anxiety or mood disorders. Relations between excessive shyness and each of the anxiety and mood disorders were examined after adjusting for elevated neuroticism, self-criticism, and low maternal care. The largest odds ratios were found for social phobia in both men and women, particularly for the complex subtype of this disorder. Significant associations also emerged for posttraumatic stress disorder in women and for major depressive disorder in men. Childhood shyness remained significantly associated with a lifetime history of social phobia when individuals with current (past year) social phobia were excluded from the analysis. The results of this study suggest that childhood shyness is strongly related to the complex subtype of social phobia in the general population. Excessive shyness does not appear to be strongly associated with other anxiety and mood disorders when related psychosocial and developmental dimensions are statistically controlled. Finally, many individuals who report excessive childhood shyness do not meet criteria for any anxiety or mood disorder. In a similar fashion, approximately 50% of individuals with a lifetime history of complex social phobia did not view themselves as very shy when growing up.  相似文献   
70.
Although the importance of recognizing posttraumatic stress disorder (PTSD) in primary care has been well-established, routine screening for PTSD remains unfeasible for many primary care clinics because of the length of the available screening instruments. Thus, the purpose of this work was to develop and validate a brief screening tool for PTSD. In Study 1, four short forms of the PTSD Checklist-civilian version were identified that captured a majority of the variance in the measure. In Study 2, the performance of these short forms was evaluated in a separate sample of primary care patients. We found that both two-item and six-item versions have adequate psychometric properties for screening purposes and suggest that the selection of one version over the other depends on the specific needs of each primary care clinic.  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