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   1379篇
  免费   90篇
  2023年   13篇
  2022年   16篇
  2021年   29篇
  2020年   41篇
  2019年   51篇
  2018年   80篇
  2017年   78篇
  2016年   73篇
  2015年   46篇
  2014年   51篇
  2013年   192篇
  2012年   64篇
  2011年   71篇
  2010年   46篇
  2009年   38篇
  2008年   49篇
  2007年   52篇
  2006年   52篇
  2005年   43篇
  2004年   30篇
  2003年   27篇
  2002年   34篇
  2001年   21篇
  2000年   18篇
  1999年   14篇
  1998年   10篇
  1997年   14篇
  1995年   10篇
  1994年   7篇
  1991年   7篇
  1990年   6篇
  1989年   9篇
  1988年   11篇
  1987年   8篇
  1986年   6篇
  1985年   11篇
  1984年   6篇
  1983年   7篇
  1982年   7篇
  1981年   11篇
  1979年   10篇
  1978年   6篇
  1975年   8篇
  1974年   7篇
  1971年   9篇
  1970年   5篇
  1969年   5篇
  1968年   7篇
  1967年   5篇
  1966年   8篇
排序方式: 共有1469条查询结果,搜索用时 15 毫秒
931.
ABSTRACT

The impact of age-related changes in visual-perceptual processing on naming ability has not been reported. The present study investigated the effects of 6 levels of spatial frequency and 6 levels of contrast on accuracy and latency to name objects in 14 young and 13 older neurologically normal adults with intact lexical-semantic functioning. Spatial frequency and contrast manipulations were made independently. Consistent with the hypotheses, variations in these two visual parameters impact naming ability in young and older subjects differently. The results from the spatial frequency-manipulations revealed that, in general, young vs. older subjects are faster and more accurate to name. However, this age-related difference is dependent on the spatial frequency on the image; differences were only seen for images presented at low (e.g., 0.25–1 c/deg) or high (e.g., 8–16 c/deg) spatial frequencies. Contrary to predictions, the results from the contrast manipulations revealed that overall older vs. young adults are more accurate to name. Again, however, differences were only seen for images presented at the lower levels of contrast (i.e., 1.25%). Both age groups had shorter latencies on the second exposure of the contrast-manipulated images, but this possible advantage of exposure was not seen for spatial frequency. Category analyses conducted on the data from this study indicate that older vs. young adults exhibit a stronger nonliving-object advantage for naming spatial frequency-manipulated images. Moreover, the findings suggest that bottom-up visual-perceptual variables integrate with top-down category information in different ways. Potential implications on the aging and naming (and recognition) literature are discussed.  相似文献   
932.
The present study examined the role of parenting styles and basic psychological needs in the adoption of goals and aspirations of learners, as well as for their psychological wellbeing (positive versus negative affect) in a South African sample of learners. A cross-sectional design was used to conduct this study with a sample of 853 learners at public schools in the Western Cape of South Africa (females?=?57%, mean age 16.96 years, SD?=?1.12). Data were collected using the Parenting Style and Dimensions Questionnaire (PSDQ), Psychological Needs Scale, Aspiration Index and the Positive And Negative Affect Schedule (PANAS). The results suggest that authoritative and authoritarian parenting styles influence the adoption of life goals and psychological wellbeing of adolescents with fathers' negative parenting possibly reducing adolescent wellbeing. Extrinsic life goals was a significant predictor of positive affect, while need frustration was a significant predictor of negative affect. These findings suggest parenting styles and basic psychological needs influence life aspirations and psychological wellbeing of learners in a developing country context.  相似文献   
933.
ObjectivesThis study examined the mediating and moderating effects of physical self-concept and parental support, respectively, on relations between maturation and physical activity (PA) in British adolescent females.DesignCross-sectional field based study.MethodsBiological maturity status, physical self-concept, perceived parental support for PA, and self-reported PA were assessed in 244 female British year 7–9 pupils (M age = 12.8 years, SD = .9).ResultsStructural equation modelling, employing maximum likelihood estimation and boot-strapping procedures supported the contention that physical self-concept mediated an inverse relation between maturation and PA. A regression model examining the main and interactive effects of maturation and parental support on PA provided evidence of a main effect for parental support, but no interactive effect.ConclusionsThe results suggest that physical self-concept partially mediates an inverse relation between maturity and physical activity in adolescent females. Accordingly, how adolescent females interpret or perceive the changes associated with maturation may be more important than maturation itself. Encouraging adolescent females to view puberty as a natural and attractive aspect of the process of ‘growing up’ may help mitigate any negative health consequences associated with early maturation. Parental support for PA does not appear to moderate relations between maturation and PA.  相似文献   
934.
In this study, associations were examined between cortisol levels of wives and husbands in 47 heterosexual married couples. Both partners' salivary cortisol levels were measured at the same moments seven times a day on 2 typical weekdays. After accounting for the effects of the diurnal rhythm of cortisol and relevant control variables, dyadic hierarchical linear modeling indicated significant positive linkages between partners' cortisol levels, consistent with the hypothesized within‐couple physiological synchrony. Variables reflecting more (spousal presence) or less connectedness (loneliness, being alone) were also collected at the time of each cortisol sample. Results indicated that husbands' cortisol levels were higher at moments they reported feeling lonelier and lower at moments they were in the presence of their spouse. Wives' cortisol levels were higher at moments they were alone. In addition, wife–husband cortisol synchrony was stronger for husbands who spent relatively more time with their spouse across the study period—even after accounting for time spent with others in general. These findings suggest that marital partners evidence positive within‐couple cortisol associations, and that connectedness (particularly physical closeness) may underpin spouses' physiological synchrony.  相似文献   
935.
Little longitudinal research has been conducted on changes in children's emotional self-regulation strategy (SRS) use after infancy, particularly for children at risk. In this study, the authors examined changes in boys’ emotional SRS from toddlerhood through preschool. Repeated observational assessments using delay of gratification tasks at ages 2, 3, and 4 years were examined with both variable- and person-oriented analyses in a low-income sample of boys (N = 117) at risk for early problem behavior. Results were consistent with theory on emotional SRS development in young children. Children initially used more emotion-focused SRS (e.g., comfort seeking) and transitioned to greater use of planful SRS (e.g., distraction) by 4 years of age. Person-oriented analysis using trajectory analysis found similar patterns from 2 to 4 years, with small groups of boys showing delayed movement away from emotion-focused strategies or delay in the onset of regular use of distraction. The results provide a foundation for future researchers to examine the development of SRS in low-income young children.  相似文献   
936.
This research is an examination of whether cognition in depressed individuals incorporates a realistic view of the world or a general tendency toward negativity. Participants provided two types of probability judgments of the likelihood that they correctly answered general knowledge questions: the probability that they correctly answered each of the individual questions and an aggregate judgment, after completing the questionnaire, of the percentage of all the questions they thought they had correctly answered. These tasks generally elicit overconfidence and accuracy in nondepressives. In accord with theories of both depressive realism and general negativity, in their item-by-item assessments of their answers to the individual questions, depressed participants demonstrated less overconfidence than nondepressed participants. In accord with the theory of general negativity but not with the theory of depressive realism, however, depressed participants demonstrated underconfidence in their aggregate judgments. The implications of these findings on theories of depressive cognition are discussed.  相似文献   
937.

Objective

Contrasts of verbal fluency and automatic speech provide an opportunity to evaluate the neural underpinnings of generativity and flexibility in autism spectrum disorders (ASD).

Method

We used functional magnetic resonance imaging (fMRI) to contrast brain activity in high functioning ASD (n = 17, mean verbal IQ = 117) and neurotypical (NT; n = 20, mean verbal IQ = 112) adolescent and young adult males (12–23 years). Participants responded to three word generation conditions: automatic speech (reciting months), category fluency, and letter fluency.

Results

Our paradigm closely mirrored behavioral fluency tasks by requiring overt, free recall word generation while controlling for differences in verbal output between the groups and systematically increasing the task demand. The ASD group showed reduced neural response compared to the NT participants during fluency tasks in multiple regions of left anterior and posterior cortices, and sub-cortical structures. Six of these regions fell in cortico-striatal circuits previously linked to repetitive behaviors (Langen, Durston, Kas, van Engeland, & Staal, 2011), and activity in two of them (putamen and thalamus) was negatively correlated with autism repetitive behavior symptoms in the ASD group. In addition, response in left inferior frontal gyrus was differentially modulated in the ASD, relative to the NT, group as a function of task demand.

Conclusions

These data indicate a specific, atypical brain response in ASD to demanding generativity tasks that may have relevance to repetitive behavior symptoms in ASD as well as to difficulties generating original verbal responses.  相似文献   
938.
The "ba, ba, ba" sound universal to babies' babbling around 7 months captures scientific attention because it provides insights into the mechanisms underlying language acquisition and vestiges of its evolutionary origins. Yet the prevailing mystery is what is the biological basis of babbling, with one hypothesis being that it is a non-linguistic motoric activity driven largely by the baby's emerging control over the mouth and jaw, and another being that it is a linguistic activity reflecting the babies' early sensitivity to specific phonetic-syllabic patterns. Two groups of hearing babies were studied over time (ages 6, 10, and 12 months), equal in all developmental respects except for the modality of language input (mouth versus hand): three hearing babies acquiring spoken language (group 1: "speech-exposed") and a rare group of three hearing babies acquiring sign language only, not speech (group 2: "sign-exposed"). Despite this latter group's exposure to sign, the motoric hypothesis would predict similar hand activity to that seen in speech-exposed hearing babies because language acquisition in sign-exposed babies does not involve the mouth. Using innovative quantitative Optotrak 3-D motion-tracking technology, applied here for the first time to study infant language acquisition, we obtained physical measurements similar to a speech spectrogram, but for the hands. Here we discovered that the specific rhythmic frequencies of the hands of the sign-exposed hearing babies differed depending on whether they were producing linguistic activity, which they produced at a low frequency of approximately 1 Hz, versus non-linguistic activity, which they produced at a higher frequency of approximately 2.5 Hz - the identical class of hand activity that the speech-exposed hearing babies produced nearly exclusively. Surprisingly, without benefit of the mouth, hearing sign-exposed babies alone babbled systematically on their hands. We conclude that babbling is fundamentally a linguistic activity and explain why the differentiation between linguistic and non-linguistic hand activity in a single manual modality (one distinct from the human mouth) could only have resulted if all babies are born with a sensitivity to specific rhythmic patterns at the heart of human language and the capacity to use them.  相似文献   
939.
Abstract: This paper examines the phenomenon of embodied countertransference: where the analyst experiences a somatic reaction rather than the more common countertransference responses of thoughts, feelings, images, fantasies and dreams. Discussion of clinical material considers neurotic and syntonic aspects. The analogy is made of resonance with a tuning fork. Several questions are posed: Why does countertransference resonate in the bodies of some analysts but not all? Why do those analysts who are sensitive to this, experience it with some patients but not with others? And what are the conditions which are conducive to producing somatic responses? It proposes that somatic reactions are more likely to occur when a number of conditions come together: when working with patients exhibiting borderline, psychotic or severe narcissistic elements; where there has been early severe childhood trauma; and where there is fear of expressing strong emotions directly. In addition another theoretical factor is proposed, namely the typology of the analyst.  相似文献   
940.
Objective: An enhanced stress and coping model was used to explain depression among HIV-positive women in healthcare and community settings where highly active anti-retroviral treatment (HAART) was commonplace. Method: HIV-infected women in four cities (N=978) were assessed, cross-sectionally, for mental and physical health, stress, social support, and other background factors. Results: Self-reported level of depressive symptomatology was high. Number of physical symptoms, illness intrusiveness, and perceived stress were positively associated with depressed mood, while coping self-efficacy and social support were negatively associated. Stress mediated the effect of health status on depression and coping self-efficacy mediated the effect of psychosocial resources on depression. Our enhanced stress and coping model accounted for 52% of variance in depressive symtpomatology. Conclusions: Interventions focused on improving coping self-efficacy, bolstering social supports, and decreasing stress in the lives of HIV-positive women may help to reduce the negative effects of HIV disease on mood.  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