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   41578篇
  免费   1683篇
  国内免费   22篇
  2020年   424篇
  2019年   474篇
  2018年   757篇
  2017年   727篇
  2016年   769篇
  2015年   534篇
  2014年   687篇
  2013年   3183篇
  2012年   1178篇
  2011年   1269篇
  2010年   718篇
  2009年   777篇
  2008年   1039篇
  2007年   1098篇
  2006年   980篇
  2005年   897篇
  2004年   839篇
  2003年   817篇
  2002年   816篇
  2001年   1431篇
  2000年   1373篇
  1999年   1051篇
  1998年   433篇
  1997年   390篇
  1996年   397篇
  1992年   871篇
  1991年   824篇
  1990年   846篇
  1989年   758篇
  1988年   761篇
  1987年   704篇
  1986年   739篇
  1985年   787篇
  1984年   619篇
  1983年   539篇
  1982年   408篇
  1981年   385篇
  1979年   652篇
  1978年   492篇
  1977年   404篇
  1975年   549篇
  1974年   683篇
  1973年   694篇
  1972年   541篇
  1971年   507篇
  1970年   464篇
  1969年   461篇
  1968年   610篇
  1967年   537篇
  1966年   533篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
Asymmetric neural control systems in human self-regulation   总被引:15,自引:0,他引:15  
  相似文献   
932.
Maternal and adolescent depression are challenges that often co-occur. Many studies have drawn bivariate associations between maternal depressive symptoms, adolescent depressive symptoms, and family conflict, but few have examined reciprocal effects. Even among extant studies, there is a lack of clarity related to directionality of influence. Three competing theoretical models may explain the relationship between maternal depressive symptoms, adolescent depressive symptoms, and family conflict, and these processes may differ by adolescents’ sex. Using three time points of data from 187 diverse mother-adolescent dyads, we fit a taxonomy of autoregressive cross-lagged structural equation models to simultaneously evaluate the competing theoretical models and also examine differences by sex using multiple-group analyses. Results indicate a symptom-driven model whereby adolescent depressive symptoms predicted increases in family conflict. Sex differences were also found. For males, but not females, greater adolescent depressive symptoms predicted subsequent increases in maternal depressive symptoms, which then predicted lower family conflict—possibly indicating maternal disengagement/withdrawal. Our findings suggest addressing adolescent depressive symptoms in order to prevent family conflict and that distinctive targets for the prevention/intervention of family conflict should account for differences by adolescents’ sex.  相似文献   
933.
African Americans are at significantly greater risk of hypertension and worse cardiovascular outcomes than other racialized groups, yet hypertension intervention effects remain limited. Thus, it is necessary to understand the potential mechanisms whereby interventions may be more effectively targeted to improve health. Supported by prior research evidence and guided by the Biobehavioral Family Model, this study examined associations between family relationship quality, psychological wellbeing, and self-management behaviors for African Americans with hypertension. Data were pooled from three Midlife Development in the U.S. projects, resulting in a sample of 317 African Americans (63.4% female, Mage = 53.32) with self-reported high blood pressure in the past 12 months. We tested four cross-sectional multiple mediator models, with depressed mood and environmental mastery mediating associations between family strain and exercise, smoking, problematic alcohol use, and stress-eating. Environmental mastery mediated the association between greater family strain and decreased odds of achieving recommended exercise levels; greater odds of reporting problematic alcohol use; and greater stress-eating. Though family strain was associated with depressed mood in each model, this variable did not serve as an indirect pathway to self-management behaviors. Family strain, and the potential pathway identified via environmental mastery, may be a meaningful predictor of disease self-management for African Americans with hypertension. Longitudinal studies are needed to examine directionality and to support intervention trials for improving self-management and hypertension outcomes.  相似文献   
934.
935.
The reinforcer pathology model posits that core behavioral economic mechanisms, including delay discounting and behavioral economic demand, underlie adverse health decisions and related clinical disorders. Extensions beyond substance use disorder and obesity, however, are limited. Using a reinforcer pathology framework, this study evaluates medical adherence decisions in patients with multiple sclerosis. Participants completed behavioral economic measures, including delay discounting, probability discounting, and a medication purchase task. A medical decision-making task was also used to evaluate how sensitivity to mild side effect risk and efficacy contributed to the likelihood of taking a hypothetical disease-modifying therapy. Less steep delay discounting and more intense (greater) medication demand were independently associated with greater adherence to the medication decision-making procedure. More generally, the pattern of interrelations between the medication-specific and general behavioral economic metrics was consistent with and contributes to the reinforcer pathology model. Additional research is warranted to expand these models to different populations and health behaviors, including those of a positive health orientation (i.e., medication adherence).  相似文献   
936.
Multiple factors have been proposed to contribute to the other-race effect in face recognition, including perceptual expertise and social-cognitive accounts. Here, we propose to understand the effect and its contributing factors from the perspectives of learning mechanisms that involve joint learning of visual attention strategies and internal representations for faces, which can be modulated by quality of contact with other-race individuals including emotional and motivational factors. Computational simulations of this process will enhance our understanding of interactions among factors and help resolve inconsistent results in the literature. In particular, since learning is driven by task demands, visual attention effects observed in different face-processing tasks, such as passive viewing or recognition, are likely to be task specific (although may be associated) and should be examined and compared separately. When examining visual attention strategies, the use of more data-driven and comprehensive eye movement measures, taking both spatial–temporal pattern and consistency of eye movements into account, can lead to novel discoveries in other-race face processing. The proposed framework and analysis methods may be applied to other tasks of real-life significance such as face emotion recognition, further enhancing our understanding of the relationship between learning and visual cognition.  相似文献   
937.
Previous research has evaluated the effects of prompt rates on the rate of communicative behavior. More recent research has suggested that dense prompting can result in communicative behavior that is more resistant to change. However, existing research has not considered the impact that higher response rates had on reinforcement rate, a variable known to impact response persistence. The current study systematically replicated previous research by evaluating communicative responding in contexts associated with dense- and lean-prompt schedules and extended existing research by (a) holding reinforcement rates similar across the two prompting schedules (lean and dense), and (b) evaluating the persistence of communicative responding in the contexts associated with each prompting schedule. The results for Experiment 1 clearly replicated and extended previous research. The results for Experiment 2 were equivocal and suggested that previous reinforcement history and response class size impacted outcomes.  相似文献   
938.
Critical action—behaviours aimed at dismantling systems of oppression—must be examined within youths' racialized experiences and should incorporate cultural and sociohistorical factors. We considered an expansive list of items capturing youth behaviours to create a novel four-factor (service, community change, expression, and care) measure of critical action for Asian and Hispanic/Latinx youth. Multiple distinct profiles of critical action were identified within both racial-ethnic groups, and associations between the profiles and sociodemographic and contextual support variables were explored. Gender differences in the type of critical action were found in both racial-ethnic groups, pointing to the potential influence of gender roles on critical action among these populations. Differences in critical action patterns were also found between those born in the U.S. versus those born outside the U.S.; access to critical action may differ within racial-ethnic groups depending on birthplace and associated nuances in familial and cultural contexts. This paper demonstrated a need for attending to variation between and within groups in the study of critical action in order to effectively support racialized youth's coping within and resistance against systems of oppression.  相似文献   
939.
In this study, we evaluated several components of a pedometer-based intervention with children in an elementary-school-aged classroom, across 24-h sessions. The intervention included combinations of self-monitoring, goal setting, feedback, and reinforcement, and data were analyzed at both the classroom level (i.e., average daily step totals) and the individual level (i.e., daily step totals), across phases. The highest levels of physical activity were observed when components of self-monitoring, public posting, goal setting, and feedback with reward were applied concurrently.  相似文献   
940.
We conducted a systematic review of research on relational sacrifices in romantic relationships from 2002 to 2021 [N = 115 studies] to answer three questions: Q1: Whose voices and vantage points are represented in the research?; Q2: What types of questions are valued?; Q3: What are the reflections and connections about relational sacrifices that were learned during the review? To address Q1, we coded sample demographics of study participants on geographical location, race/ethnicity, education/income/SES, gender (i.e., gender differences explored and beyond gender binaries), sexual orientation, age, and disability, using a coding system of 1 (exclusion/absence) to 5 (focus on context-relevant experiences for underrepresented samples). Results for Q1 showed that the most frequent codes were 1 (exclusion/absence) for information about the samples' disability status, education/income/SES, and both codes for gender (i.e., gender differences explored and beyond gender binaries); when demographic information was reported, the most frequent codes were 2 (compensatory addition) for age, sexual orientation, geographical location, and race/ethnicity. To address Q2, we coded for aspects of the study designs and conceptual dimensions of sacrifice. Results for Q2 showed that a majority of the studies in our review used quantitative and close-ended measures emphasizing behavioral frequency of sacrifice. For Q3, we include our own reflections and connections about relational sacrifices, questioning research methods, and challenging assumptions drawn from existing research to move toward a more inclusive science.  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