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   875篇
  免费   251篇
  国内免费   46篇
  2024年   2篇
  2023年   13篇
  2022年   8篇
  2021年   32篇
  2020年   17篇
  2019年   76篇
  2018年   98篇
  2017年   103篇
  2016年   78篇
  2015年   58篇
  2014年   38篇
  2013年   97篇
  2012年   26篇
  2011年   39篇
  2010年   36篇
  2009年   41篇
  2008年   34篇
  2007年   24篇
  2006年   28篇
  2005年   17篇
  2004年   12篇
  2003年   10篇
  2002年   8篇
  2001年   12篇
  2000年   6篇
  1999年   7篇
  1998年   5篇
  1997年   3篇
  1996年   3篇
  1995年   3篇
  1994年   2篇
  1993年   1篇
  1992年   3篇
  1991年   6篇
  1988年   1篇
  1985年   25篇
  1984年   21篇
  1983年   25篇
  1982年   28篇
  1981年   20篇
  1980年   21篇
  1979年   28篇
  1978年   10篇
  1977年   15篇
  1976年   16篇
  1975年   9篇
  1974年   5篇
  1973年   2篇
排序方式: 共有1172条查询结果,搜索用时 62 毫秒
41.
42.
Flow is a special mental state characterized by deep concentration that occurs during the performance of optimally challenging tasks. In prior studies, proneness to experience flow has been found to be moderately heritable. In the present study, we investigated whether individual differences in flow proneness are related to a polymorphism of the dopamine D2 receptor coding gene (DRD2 C957T rs6277). This polymorphism affects striatal D2 receptor availability, a factor that has been shown to be related to flow proneness. To our knowledge, this is the first study to investigate the association between this trait and a specific gene variant. In a sample of 236 healthy Hungarian adults, we found that CC homozygotes report higher flow proneness than do T allele carriers, but only during mandatory activities (i.e., studying and working), not during leisure time. We discuss implications of this result, e.g., the potential mediators of the relationship.  相似文献   
43.
Initial evidence suggests that gains in relationship functioning from brief, web‐based programs are maintained through one year following the intervention; however, whether these results generalize to a low‐income sample is unclear. Furthermore, previous research from in‐person couple therapy suggests there may be different shapes of maintenance slopes for behavioral versus acceptance‐based techniques. This study contacted 668 individuals who enrolled in online behavioral (ePREP) or acceptance‐based (OurRelationship) programs one year following completion of the program. Multilevel modeling was used to examine linear and quadratic rates of change in the year following the online intervention as well as total amount of change from pretreatment to 12‐month follow‐up for both relationship and individual functioning. The majority of couples who responded continued to be in a relationship with the same partner (68.3%). Examinations of relationship functioning indicated couples in both programs maintained their gains over follow‐up (i.e., no significant linear or quadratic changes), with medium‐to‐large within‐group effect sizes from pre‐ to one‐year follow‐up. There were no significant differences in relationship outcomes between OurRelationship and ePREP. Similarly, examinations of individual functioning outcomes indicated couples maintained their gains over follow‐up or continued to improve. In total, couples experienced small‐to‐medium within‐group effect sizes from pretreatment to one‐year follow‐up, with larger effects for individuals who were initially distressed. These results suggest that online programs create lasting change for low‐income couples in relationship and individual functioning, with minimal differences between behavioral and acceptance‐based orientations.  相似文献   
44.
Knowledge and understanding about the impact of cumulative adverse experiences on the health and wellbeing of children, adolescents, and adults has rapidly expanded over the past 30 years. Despite the invaluable attention and support this proliferation has drawn to the importance of early childhood experiences, we believe that it is time to move beyond broad indices of risk and toward more specific and individualized understanding of how risk exposures are linked to clinical outcomes in young children. Within infant and early childhood mental health, there is a need for greater specificity in linking adverse caregiving experiences in early life to psychopathology in children. We highlight a framework distinguishing experiences of trauma from experiences of deprivation and use the examples of posttraumatic stress disorder and reactive attachment disorder to demonstrate how greater specificity in our understanding of early adverse caregiving can lead to more accurate and targeted diagnosis and treatment for young children. Both researchers and clinicians benefit from an approach to gain a greater appreciation of the links between specific types of experiences and outcomes in the children that we serve.  相似文献   
45.
IntroductionDepression and anxiety are important risk factors for diabetes and high blood pressure.ObjectiveThis study investigated the effectiveness of the Cognitive-Behavioral Group Intervention for Diabetes Disease (CBGI-DD) in reducing depression and anxiety in female patients with type 2 diabetes (T2D).MethodThe CBGI-DD program includes 12 weekly 2.5 h sessions, spread weekly over the course of 3 months. The present study was semi-experimental and controlled, with assessments at pre-test and post-test. It included diagnostic criteria for the diagnosis of T2D in the patient's medical records by a diabetes specialist. Participants (62 female volunteers aged 25 to 75 years) were randomly allocated to a control or test group. Both groups responded to the Second edition of the Beck Depression Inventory (BDI-II) and the Beck Anxiety Inventory (BAI) before (pretest) and immediately after the intervention (posttest). Participants in the test group received CBGI-DD (from April up to the end of September 2018) at Mashhad Diabetes Center. The control group received only medical care during this period.ResultsAn analysis of covariance showed that compared to the control group, the test group had a significant reduction in anxiety and depression from pre-test to post-test (p < 0.05). It was compared post-test scores between the two groups, controlling for pre-test scores.ConclusionThe CBGI-DD program seems to be effective in reducing anxiety and depression in female patients with T2D. However, further research exploring the potential for long-term improvements in depression and anxiety is needed.  相似文献   
46.
Electrical stimulation of the region of the lateral hypothalamus produced a consistent form of quiet-biting attack behavior in cats. In one series of experiments, cats, implanted with electrodes from which attack had been elicited, were anesthetized and then were injected with a bolus of 14C-2-deoxyglucose at the same time as electrical stimulation was delivered through the attack electrodes. Brains prepared for X-ray autoradiography revealed that lateral hypothalamic stimulation activated the classical medial forebrain bundle pathway supplying the septal region, diagonal band, lateral preoptic area, and ventral tegmental region. Stimulation of quiet-attack sites in perifornical hypothalamus resulted in the activation of a much more extensive projection system which included the central and lateral tegmental fields of the midbrain and pons, and central gray region, as well as the structures described above. In a second series of experiments, 3H-leucine was placed into the region of the electrode tip from which attack was elicited in order to identify more precisely the pathways arising from that site. In general, tritiated amino acid radioautography replicated the 14C-2-deoxyglucose findings. In addition, the amino acid radioautographic data revealed the presence of extensive projections from perifornical hypothalamus to such pontine structures as the nucleus locus coeruleus, motor nucleus of NV , and the lateral pontine tegmental field. The functional connections between the lateral hypothalamic “attack region” and lateral preoptic zone were also confirmed by electrophysiological methods.  相似文献   
47.
急性应激会增强个体对威胁刺激的注意偏向, 但急性应激是增强了对威胁刺激的注意定向还是损害了对威胁刺激的注意解除还不清楚。本研究采用社会评估冷压任务和点探测任务, 结合事件相关电位技术, 考察急性应激对威胁刺激注意偏向影响的认知机制。在进行社会评估冷压任务后, 应激组个体的状态焦虑和皮质醇浓度显著升高。在注意偏向中, 应激组对威胁刺激的注意解除比控制组更慢, 应激组和控制组在对威胁刺激的注意定向上无显著差异。ERP结果上, 威胁刺激诱发应激组比控制组产生了更负的SPCN, 在N2pc上没有显著差异。应激组和控制组皮质醇增量的差异和N2pc、SPCN的组间差异均有显著正相关。这些结果说明, 急性应激增强对威胁刺激的注意偏向是因为其损害个体对威胁刺激的注意解除, 这可能是因为急性应激损害了与注意解除相关的额-顶网络的功能所致。  相似文献   
48.
目的:探讨语言熟练度对Stroop效应的影响及其背后的脑机制。材料与方法:17位被试参与本研究。被试母语为汉语,第二语言为英语。在被试完成中英文的stroop色字的任务过程中对被试进行fMRI扫描。结果:在色字相一致的条件下,中文任务与英文任务相比,双侧背侧枕叶及右侧背外侧前额叶有更强的激活; 反向比较,双侧腹侧枕叶有更强的激活。在色字不一致的条件下,中文任务与英文任务相比,双侧背外侧前额叶、右侧枕下回有更强的激活; 反向比较,并无显著激活的脑区。此外,中文Stroop效应引起左侧额下回显著的激活。英文Stroop效应中,左侧额下回无显著激活。结论:结合前人研究,我们得出,语言熟练度影响了对注意控制有重要作用的背外侧前额叶以及与反应抑制有关的左侧额下回在Stroop任务中的参与程度,进而影响了Stroop任务的表现  相似文献   
49.
This research study focused on the evaluation of an emulated in-vehicle Active Traffic and Demand Management (ATDM) system on Interstate 66 in Northern Virginia. Traditional ATDM systems rely on infrastructure-mounted variable message signs (VMS) to provide information (speed limits, lane availability, etc.) to the traveling public. By providing information about dynamic roadway conditions on an in-vehicle device, the ATDM may improve driving safety and performance by allowing drivers to remain consistently aware of forthcoming traffic conditions and roadway requirements; even when external signage is inaccessible. This study represents an initial investigation of an emulated in-vehicle ATDM to provide developers with design guidance and ensure that unintended consequences, such as distraction, do not undermine the potential benefits.Twenty younger and 20 older participants, accompanied by a member of the research team, experienced the following ATDM features on an in-vehicle device (IVD) mounted to the dashboard: (1) dynamic speed limits, (2) dynamic lane use/shoulder control, (3) High Occupancy Vehicle (HOV) restrictions, and (4) roadway information from variable message signs. The IVD was equipped with auditory and visual alerts notifying the driver when relevant visual information was updated. Research questions addressed distraction and driver behavior associated with use of the system. Qualitative and quantitative participant data was acquired from the instrumented vehicle, various questionnaires, and researcher observation.Several key findings were uncovered: (1) The IVD, as tested, did not warrant classification as a source of distraction according to the NHTSA guidelines; v2) There was a significant difference in eye-glance durations to the IVD when comparing the VMS alerts to both the speed limit and lane management alerts; and (3) The speed limit alert motivated participants to alter their speed (per survey results and participant speed data).  相似文献   
50.
We investigated public acceptance of conditionally automated (SAE Level 3) passenger cars using a questionnaire study among 9,118 car-drivers in eight European countries, as part of the European L3Pilot project. 71.06% of respondents considered conditionally automated cars easy to use while 28.03% of respondents planned to buy a conditionally automated car once it is available. 41.85% of respondents would like to use the time in the conditionally automated car for secondary activities. Among these 41.85%, respondents plan to talk to fellow travellers (44.76%), surf the internet, watch videos or TV shows (44%), observe the landscape (41.70%), and work (17.06%). The UTAUT2 (Unified Theory of Acceptance and Use of Technology) was applied to investigate the effects of performance and effort expectancy, social influence, facilitating conditions, and hedonic motivation on the behavioural intention to use conditionally automated cars. Structural equation analysis revealed that the UTAUT2 can be applied to conditional automation, with hedonic motivation, social influence, and performance expectancy influencing the behavioural intention to buy and use a conditionally automated car. The present study also found positive effects of facilitating conditions on effort expectancy and hedonic motivation. Social influence was a positive predictor of hedonic motivation, facilitating conditions, and performance expectancy. Age, gender and experience with advanced driver assistance systems had significant, yet small (<0.10), effects on behavioural intention. The implications of these results on the policy and best practices to enable large-scale implementation of conditionally automated cars on public roads are discussed.  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