全文获取类型
收费全文 | 37206篇 |
免费 | 716篇 |
国内免费 | 2篇 |
专业分类
37924篇 |
出版年
2020年 | 356篇 |
2019年 | 495篇 |
2018年 | 653篇 |
2017年 | 695篇 |
2016年 | 693篇 |
2015年 | 482篇 |
2014年 | 624篇 |
2013年 | 2827篇 |
2012年 | 1093篇 |
2011年 | 1157篇 |
2010年 | 695篇 |
2009年 | 692篇 |
2008年 | 1038篇 |
2007年 | 1002篇 |
2006年 | 924篇 |
2005年 | 852篇 |
2004年 | 808篇 |
2003年 | 749篇 |
2002年 | 771篇 |
2001年 | 1050篇 |
2000年 | 982篇 |
1999年 | 752篇 |
1998年 | 443篇 |
1996年 | 358篇 |
1992年 | 598篇 |
1991年 | 565篇 |
1990年 | 559篇 |
1989年 | 575篇 |
1988年 | 573篇 |
1987年 | 524篇 |
1986年 | 566篇 |
1985年 | 607篇 |
1984年 | 508篇 |
1983年 | 471篇 |
1982年 | 392篇 |
1981年 | 385篇 |
1979年 | 558篇 |
1978年 | 424篇 |
1977年 | 363篇 |
1976年 | 407篇 |
1975年 | 485篇 |
1974年 | 534篇 |
1973年 | 556篇 |
1972年 | 441篇 |
1971年 | 415篇 |
1970年 | 413篇 |
1969年 | 435篇 |
1968年 | 526篇 |
1967年 | 443篇 |
1966年 | 442篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
Contemporary models of ADHD hypothesize that hyperactivity reflects a byproduct of inhibition deficits. The current study investigated the relationship between children's motor activity and behavioral inhibition by experimentally manipulating demands placed on the limited-resource inhibition system. Twenty-two boys (ADHD = 11, TD = 11) between the ages of 8 and 12 years completed a conventional stop-signal task, two choice-task variants (no-tone, ignore-tone), and control tasks while their motor activity was measured objectively by actigraphs placed on their nondominant wrist and ankles. All children exhibited significantly higher activity rates under all three experimental tasks relative to control conditions, and children with ADHD moved significantly more than typically developing children across conditions. No differences in activity level were observed between the inhibition and noninhibition experimental tasks for either group, indicating that activity level was primarily associated with basic attentional rather than behavioral inhibition processes. 相似文献
962.
Stress, depending on intensity and duration, elicits adaptive or maladaptive physiological effects. Increasing evidence shows those patterns of advantageous versus deleterious physiologic stress effects also exist for some brain functions, including learning and memory. For example, short stress enhances, while chronic stress impairs, performance on numerous cognitive tasks in male rats. In contrast, performance of female rats is enhanced, or not altered, following both short-term and long-term stress exposure on the same behavioral tasks. The current study was designed to better characterize the behavioral effects of sustained chronic restraint stress in female rats. Female Sprague Dawley rats were assigned to a stress (restraint, 6 h/day, 35 days) or control (no stress) condition, weighed weekly, and then tested on open field (OF), object recognition (OR) and object placement (OP) tasks. Stressed females gained less weight during stress than controls. On the OF, there were no group differences in locomotor activity, but stressed females made fewer inner visits than controls, indicating increased anxiety. Both groups successfully performed the OP and OR tasks across all inter-trial delays, indicating intact non-spatial and spatial memory in both control and stress females. The current results provide preliminary evidence that the commonly used chronic restraint stress model may not be an efficient stressor to female rats. 相似文献
963.
A central question in intertemporal decision making is why people reverse their own past choices. Someone who initially prefers a long-run outcome might fail to maintain that preference for long enough to see the outcome realized. Such behavior is usually understood as reflecting preference instability or self-control failure. However, if a decision maker is unsure exactly how long an awaited outcome will be delayed, a reversal can constitute the rational, utility-maximizing course of action. In the present behavioral experiments, we placed participants in timing environments where persistence toward delayed rewards was either productive or counterproductive. Our results show that human decision makers are responsive to statistical timing cues, modulating their level of persistence according to the distribution of delay durations they encounter. We conclude that temporal expectations act as a powerful and adaptive influence on people's tendency to sustain patient decisions. 相似文献
964.
The proposed changes to the personality disorder section of the Diagnostic and statistical manual of mental disorders (5th ed.) places an increased focus on interpersonal impairment as one of the defining features of personality psychopathology. In addition, a proposed trait model has been offered to provide a means of capturing phenotypic variation on the expression of personality disorder. In this study, the authors subject the proposed DSM-5 traits to interpersonal analysis using the inventory of interpersonal problems-circumplex scales via the structural summary method for circumplex data. DSM-5 traits were consistently associated with generalized interpersonal dysfunction suggesting that they are maladaptive in nature, the majority of traits demonstrated discriminant validity with prototypical and differentiated interpersonal problem profiles, and conformed well to a priori hypothesized associations. These results are discussed in the context of the DSM-5 proposal and contemporary interpersonal theory, with a particular focus on potential areas for expansion of the DSM-5 trait model. 相似文献
965.
SB de Boer FV van Oort MC Donker F Verheij AE Boon 《Journal of psychopathology and behavioral assessment》2012,34(3):415-422
Childhood characteristics are associated with life-course-persistent antisocial behavior in epidemiological studies in general population samples. The present study examines this association in an inpatient sample. The purpose is to identify easily measurable childhood characteristics that may guide choice of treatment for adolescent psychiatric inpatients with severe disruptive behavior. Patients (N?=?203) were divided into two groups with either early-onset (EO) or adolescent-onset (AO) disruptive behavior, based on ages at which professional care was used for disruptive behavior, referral to special education, and criminal offences. Both groups differed on several childhood characteristics. No gender differences in these characteristics were found. Logistic regression analysis indicated that individuals with grade retention in primary school, childhood impulsive behavior, and a history of physical abuse, had the highest probability of being member of the EO group. These characteristics are reasonably easy to identify, likely apply to other clinical samples as well, and may help clinicians to target their treatment. 相似文献
966.
Reports of sex differences in wayfinding have typically used paradigms sensitive to the female advantage (navigation by landmarks) or sensitive to the male advantage (navigation by cardinal directions, Euclidian coordinates, environmental geometry, and absolute distances). The current virtual navigation paradigm allowed both men and women an equal advantage. We studied sex differences by systematically varying the number of landmarks. Eye tracking was used to quantify sex differences in landmark utilisation as participants solved an eight-arm radial maze task within different virtual environments. To solve the task, participants were required to remember the locations of target objects within environments containing 0, 2, 4, 6, or 8 landmarks. We found that, as the number of landmarks available in the environment increases, the proportion of time men and women spend looking at landmarks and the number of landmarks they use to find their way increases. Eye tracking confirmed that women rely more on landmarks to navigate, although landmark fixations were also associated with an increase in task completion time. Sex differences in navigational behaviour occurred only in environments devoid of landmarks and disappeared in environments containing multiple landmarks. Moreover, women showed sustained landmark-oriented gaze, while men's decreased over time. Finally, we found that men and women use spatial and response strategies to the same extent. Together, these results shed new light on the discrepancy in landmark utilisation between men and women and help explain the differences in navigational behaviour previously reported. 相似文献
967.
Benjamin E. Baran Linda Rhoades Shanock Lindsay R. Miller 《Journal of business and psychology》2012,27(2):123-147
Purpose
This review focuses and aids the development of organizational support theory, which explains relationships between employers and employees based on social exchange. Many studies have explored the theory??s central construct, perceived organizational support (POS), or the degree to which employees believe their work organization values their contributions and cares about their well-being. Since the last review of POS literature in 2000, the occupational landscape has shifted, increasing nontraditional work relationships and the importance of managing an international workforce while considering influences on employee well-being. This review discusses how the recent POS research reflects these trends.Design/Methodology/Approach
This review focused on how themes in the POS research since 2000 have enhanced organizational support theory as relevant to the twenty-first century world of work.Findings
Four important theoretical themes have developed since 2000 that enhance organizational support theory: considerations of employee well-being, nontraditional workers, international and cross-cultural issues, and developments tied to the use of multilevel modeling.Implications
Giving both researchers and practitioners a synthesized view of the current status of POS research, this review serves as a springboard for new developments. It also integrates the multitude of recent studies into organizational support theory, focusing theoretical progress.Originality/Value
This is the first review and theoretical integration of the POS literature since 2002. It is a valuable resource for all interested in the field, with theoretical insights, useful tables, explanatory figures, and references. 相似文献968.
Stutterheim SE Bos AE Shiripinda I de Bruin M Pryor JB Schaalma HP 《Psychology & health》2012,27(4):395-411
HIV-related stigma in African and Afro-Caribbean diaspora communities in the Netherlands was investigated. Interviews with HIV-positive and HIV-negative community members demonstrated that HIV-related stigma manifests as social distance, physical distance, words and silence. The psychological consequences of HIV-related stigma among those diagnosed with HIV reported were emotional pain, sadness, loneliness, anger, frustration and internalised stigma. The social consequences included decreased social network size, limited social support and social isolation, and resulted from not only enacted stigma but also self-imposed social withdrawal. Also, poor treatment adherence was a health-related consequence. People living with HIV employed both problem-focused and emotion-focused coping strategies to mitigate the negative consequences of stigma. Problem-focused coping strategies included selective disclosure, disengagement, affiliating with similar others, seeking social support and, to a lesser extent, activism. Emotion-focused strategies included distraction, positive reappraisal, religious coping, external attributions, disidentification and acceptance. HIV-related stigma clearly permeates African and Afro-Caribbean communities in the Netherlands, and should be targeted for intervention. 相似文献
969.
970.
ABSTRACT To grasp an object the digits need to be placed at suitable positions on its surface. The selection of such grasping points depends on several factors. Here the authors examined whether being able to see 1 of the selected grasping points is such a factor. Subjects grasped large cylinders or oriented blocks that would normally be grasped with the thumb continuously visible and the final part of the index finger's trajectory occluded by the object in question. An opaque screen that hid the thumb's usual grasping point was used to examine whether individuals would choose a grip that was oriented differently to maintain vision of the thumb's grasping point. A transparent screen was used as a control. Occluding the thumb's grasping point made subjects move more carefully (adopting a larger grip aperture) and choose a slightly different grip orientation. However, the change in grip orientation was much too small to keep the thumb visible. The authors conclude that humans do not particularly aim for visible grasping points. 相似文献