全文获取类型
收费全文 | 3663篇 |
免费 | 269篇 |
专业分类
3932篇 |
出版年
2023年 | 59篇 |
2022年 | 50篇 |
2021年 | 91篇 |
2020年 | 135篇 |
2019年 | 146篇 |
2018年 | 198篇 |
2017年 | 171篇 |
2016年 | 188篇 |
2015年 | 153篇 |
2014年 | 158篇 |
2013年 | 570篇 |
2012年 | 253篇 |
2011年 | 236篇 |
2010年 | 129篇 |
2009年 | 142篇 |
2008年 | 192篇 |
2007年 | 165篇 |
2006年 | 121篇 |
2005年 | 104篇 |
2004年 | 84篇 |
2003年 | 105篇 |
2002年 | 93篇 |
2001年 | 61篇 |
2000年 | 43篇 |
1999年 | 31篇 |
1998年 | 25篇 |
1997年 | 19篇 |
1996年 | 23篇 |
1995年 | 14篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 14篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 19篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1971年 | 5篇 |
1937年 | 3篇 |
排序方式: 共有3932条查询结果,搜索用时 15 毫秒
161.
Sandström A Säll R Peterson J Salami A Larsson A Olsson T Nyberg L 《Stress (Amsterdam, Netherlands)》2012,15(5):503-513
Deficits in executive functioning and working memory associated with frontal lobe dysfunction are prominent in depression and work-related long-term sick leave (LTSL). This study used functional magnetic resonance imaging (fMRI) to investigate potential differences in brain activation patterns in these conditions. In addition, the function of the hypothalamic-pituitary-adrenal (HPA) axis was examined and compared between groups. Since there is a clear overrepresentation of women in these diagnostic groups, and to ensure a more homogenous sample population, only women were included. To examine the neural correlates of relevant cognitive processes in patients on sick leave >90 days due to work-related LTSL, recently diagnosed patients with major depression Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV criteria, untreated), and healthy controls (n?=?10, each group), a 2-back working memory task and a visual long-term memory task were administered during fMRI scanning. HPA axis functioning was investigated using a diurnal curve of saliva cortisol and a dexamethasone suppression test. Task performance was comparable among the three groups. Multivariate image analysis revealed that both memory tasks engaged a similar brain network in all three groups, including the prefrontal and parietal cortex. During the 2-back task, LTSL patients had significant frontal hypoactivation compared to controls and patients with depression. Saliva cortisol measurements showed a flattening of the diurnal rythmicity in LTSL patients compared to patients with depression and healthy contols. Taken together, these findings indicate that work stress-related LTSL and major depression are dissociable in terms of frontal activation and diurnal cortisol rhythmicity. 相似文献
162.
Julie Mooney‐Somers Anna Olsen Wani Erick Robert Scott Angie Akee Lisa Maher 《Journal of community & applied social psychology》2012,22(6):519-532
National surveillance data indicate marked differences between Indigenous and other Australians in the prevalence of many sexually transmitted infections (STIs). Young Indigenous people bear a particularly high burden of these infections. A collaboration of university researchers, Indigenous health workers and young Indigenous people conducted 45 field interviews to examine how young Indigenous Australians keep themselves healthy and protected against STIs. Our findings emphasise the complexity of health behaviours, where individuals are rarely always ‘risky’ or always ‘safe’, as well as subtle gender differences in health practices. Preventive strategies employed by the young people were contingent on beliefs and knowledge about sexual partners, the type of relationship, the context of the sexual encounter and access to condoms. Tangible strengths such as young Indigenous people's commitments to condoms and STI screening should be celebrated and bolstered to enhance their ability to protect themselves against adverse health outcomes and enhance their resilience against STIs. Focusing on strengths helps to counter the deficit model of health commonly deployed in Indigenous health research and draws attention to health issues facing young Indigenous people and their communities, without reinforcing negative stereotypes or focusing solely on individual risk behaviour. We provide concrete recommendations for health promotion and education. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
163.
Induction of lucid dreams: A systematic review of evidence 总被引:1,自引:0,他引:1
In lucid dreams the dreamer is aware of dreaming and often able to influence the ongoing dream content. Lucid dreaming is a learnable skill and a variety of techniques is suggested for lucid dreaming induction. This systematic review evaluated the evidence for the effectiveness of induction techniques. A comprehensive literature search was carried out in biomedical databases and specific resources. Thirty-five studies were included in the analysis (11 sleep laboratory and 24 field studies), of which 26 employed cognitive techniques, 11 external stimulation and one drug application. The methodological quality of the included studies was relatively low. None of the induction techniques were verified to induce lucid dreams reliably and consistently, although some of them look promising. On the basis of the reviewed studies, a taxonomy of lucid dream induction methods is presented. Several methodological issues are discussed and further directions for future studies are proposed. 相似文献
164.
Bank AM Barr R Calvert SL Parrott WG McDonough SC Rosenblum K 《Journal of child and family studies》2012,21(2):208-216
We describe the association between postpartum depression and the quantity and content of infant media use. Households with
depressed mothers viewed twice as much television as households with non-depressed mothers did, and depressed mothers appeared
to derive comparatively greater pleasure from television viewing. Maternal depression was associated with an increased exposure
to child-directed content by 6–9-month-old infants, although it was not associated with an increased exposure to adult-directed
programming. Depressed mothers also reported being less likely to sit and talk with their children during television use or
to consult outside sources of information about media. This increase in television exposure without corresponding parental
involvement could negatively affect developmental outcomes. 相似文献
165.
Using two clinical samples of patients, the presented studies examined the construct validity of the recently revised Anxiety Sensitivity Index-3 (ASI-3). Confirmatory factor analyses established a clear three-factor structure that corresponds to the postulated subdivision of the construct into correlated somatic, social, and cognitive components. Participants with different primary clinical diagnoses differed from each other on the ASI-3 subscales in theoretically meaningful ways. Specifically, the ASI-3 successfully discriminated patients with anxiety disorders from patients with nonanxiety disorders. Moreover, patients with panic disorder or agoraphobia manifested more somatic concerns than patients with other anxiety disorders and patients with nonanxiety disorders. Finally, correlations of the ASI-3 scales with other measures of clinical symptoms and negative affect substantiated convergent and discriminant validity. Substantial positive correlations were found between the ASI-3 Somatic Concerns and body vigilance, between Social Concerns and fear of negative evaluation and socially inhibited behavior, and between Cognitive Concerns and depression symptoms, anxiety, fear of negative evaluation, and subjective complaints. Moreover, Social Concerns correlated negatively with dominant and intrusive behavior. Results are discussed with respect to the contribution of the ASI-3 to the assessment of anxiety-related disorders. 相似文献
166.
Major brain functions depend on neuronal processes that favor the plasticity of neuronal circuits while at the same time maintaining their stability. The mechanisms that regulate brain plasticity are complex and engage multiple cascades of molecular components that modulate synaptic efficacy. Protein kinases (PKs) and phosphatases (PPs) are among the most important of these components that act as positive and negative regulators of neuronal signaling and plasticity, respectively. In these cascades, the PP protein phosphatase 2B or calcineurin (CaN) is of particular interest because it is the only Ca(2+)-activated PP in the brain and a major regulator of key proteins essential for synaptic transmission and neuronal excitability. This review describes the primary properties of CaN and illustrates its functions and modes of action by focusing on several representative targets, in particular glutamate receptors, striatal enriched protein phosphatase (STEP), and neuromodulin (GAP43), and their functional significance for synaptic plasticity and memory. 相似文献
167.
Ecological valence theory (EVT; Palmer & Schloss, Proceedings of the National Academy of Sciences 107:8877–8882, 2010) proposes that color preferences are due to affective responses to color-associated objects: That is, people generally like
colors to the degree that they like the objects associated with those colors. Palmer and Schloss found that the average valence
of objects associated with a color, when weighted by how well the objects matched the color (weighted affective valence estimates:
WAVE) explained 80% of the variation in preference across colors. Here, we replicated and extended Palmer and Schloss’s investigation
to establish whether color–object associations can account for sex differences in color preference and whether the relationship
between associated objects and color preference is equally strong for males and females. We found some degree of sex specificity
to the WAVEs, but the relationship between WAVE and color preference was significantly stronger for males than for females
(74% shared variance for males, 45% for females). Furthermore, analyses identified a significant inverse relationship between
the number of objects associated with a color and preference for the color. Participants generally liked colors associated
with few objects and disliked colors associated with many objects. For the sample overall and for females alone, this association
was not significantly weaker than the association of the WAVE and preference. The success of the WAVE at capturing color preference
was partly due to the relationship between the number of associated objects and color preference. The findings identify constraints
of EVT in its current form, but they also provide general support for the link between color preference and color–object associations. 相似文献
168.
Rivkin A Alexander RC Knighton J Hutson PH Wang XJ Snavely DB Rosah T Watt AP Reimherr FW Adler LA 《Journal of attention disorders》2012,16(8):664-674
Objective: Preclinical models, receptor localization, and genetic linkage data support the role of D4 receptors in the etiology of ADHD. This proof-of-concept study was designed to evaluate MK-0929, a selective D4 receptor antagonist as treatment for adult ADHD. Method: A randomized, double-blind, placebo-controlled, crossover study was conducted in adults with primary ADHD. The primary end point was changed from baseline in total score on the Adult ADHD Investigator Symptom Rating Scale following a 4-week treatment regimen. Additional measures included Clinical Global Impression-Severity Scale, Hospital Anxiety and Depression Scale, and Brown Attention Deficit Disorder Scale and D4 genotype analysis. Results: No statistically significant treatment differences were found between MK-0929 and placebo in any of the primary or secondary assessments. Conclusion: Results from this study suggest that blockade of the D4 receptor alone is not efficacious in the treatment of adult ADHD. 相似文献
169.
Although the number of patients needing organ transplantation systematically increases, recent years have seen a considerable shortage of donors. The level of knowledge and attitudes toward donation are critical factors in achieving the required balance between supply and demand. This pilot study assessed the knowledge, opinions, and behaviors related to organ donation and transplantation among 625 students representing eight different fields of study from the University of Rzeszow in south-eastern Poland. Although the participants provided evidence of knowledge about human organ donation and transplantation, they were aware of the main organs of the human body for potential transplants, and generally showed positive attitudes; only 24% of the subjects indicated their willingness to register as a donor; only 3% stated that they had already registered and had a donor card. The findings suggest that good intentions do not translate into action and that Poland needs to develop a nation-wide, up-to-date, and youth-oriented health education program that builds on favorable attitudes toward organ donation and transplantation. 相似文献
170.
Some children’s social activities are structured by joint goals. In previous research, the criterion used to determine this was relatively weak: if the partner stopped interacting, did the child attempt to re‐engage her? But re‐engagement attempts could easily result from the child simply realizing that she needs the partner to reach her own goal in the activity (social tool explanation). In two experiments, 21‐ and 27‐month‐old children interacted with an adult in games in which they either did or did not physically need the partner to reach a concrete goal. Moreover, when the partner stopped interacting, she did so because she was either unwilling to continue (breaking off from the joint goal) or unable to continue (presumably still maintaining the joint goal). Children of both age groups encouraged the recalcitrant partner equally often whether she was or was not physically needed for goal attainment. In addition, they did so more often when the partner was unable to continue than when she was unwilling to continue. These findings suggest that young children do not just view their collaborative partners as mindless social tools, but rather as intentional, cooperative agents with whom they must coordinate intentional states. 相似文献