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   17164篇
  免费   258篇
  国内免费   120篇
教育   11833篇
科学研究   2153篇
各国文化   141篇
体育   1516篇
综合类   11篇
文化理论   143篇
信息传播   1745篇
  2021年   125篇
  2020年   241篇
  2019年   381篇
  2018年   493篇
  2017年   457篇
  2016年   451篇
  2015年   288篇
  2014年   390篇
  2013年   3153篇
  2012年   346篇
  2011年   388篇
  2010年   288篇
  2009年   291篇
  2008年   312篇
  2007年   338篇
  2006年   316篇
  2005年   314篇
  2004年   287篇
  2003年   288篇
  2002年   279篇
  2001年   293篇
  2000年   323篇
  1999年   312篇
  1998年   168篇
  1997年   169篇
  1996年   204篇
  1995年   192篇
  1994年   149篇
  1993年   174篇
  1992年   251篇
  1991年   231篇
  1990年   242篇
  1989年   254篇
  1988年   202篇
  1987年   233篇
  1986年   215篇
  1985年   241篇
  1984年   214篇
  1983年   205篇
  1982年   172篇
  1981年   165篇
  1980年   144篇
  1979年   243篇
  1978年   183篇
  1977年   174篇
  1976年   142篇
  1975年   130篇
  1974年   146篇
  1973年   125篇
  1971年   115篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Working memory training improves children's cognitive performance on untrained tasks; however, little is known about the underlying neural mechanisms. This was investigated in 32 typically developing children aged 10–14 years (19 girls and 13 boys) using a randomized controlled design and multi-modal magnetic resonance imaging (Devon, UK; 2015–2016). Training improved working memory performance and increased intrinsic functional connectivity between the bilateral intraparietal sulci. Furthermore, improvements in working memory were associated with greater recruitment of the left middle frontal gyrus on a complex span task. Repeated engagement of fronto-parietal regions during training may increase their activity and functional connectivity over time, affording greater working memory performance. The plausibility of generalizable cognitive benefits from a neurobiological perspective and implications for neurodevelopmental theory are discussed.  相似文献   
2.
It is generally acknowledged that expatriate British players and coaches were instrumental in soccer’s radiant global diffusion and that different technical and tactical emphases developed according to particular geographical locations and cultural milieu. As the twentieth century unfolded, the trend reversed with increased inward flows of elite foreign playing and coaching labour challenging the distinctive and erstwhile dominant occupational culture of the English game. This paper explores the dynamics and tensions of subcultural modification and adaptation at the British: migrant coaching talent interface. Owing to issues associated with access, the occupational subculture of elite-level football is impenetrable to most researchers. Previous employment in professional soccer allowed this author to overcome such impediments, permitting access to a range of high-status national and international players and coaches (n = 25) affecting and affected by occupational subcultural change. This enabled a distinctive research platform combining insider knowledge and grounded experience with academic orthodoxy. The paper is built upon primary data collected in semi-structured interviews and critical analysis of emerging themes. In doing so, it offers a fresh dimension to understanding the impact of globalization on elite professional English soccer. Key findings indicated the opinion of British coaches on the impact of this foreign influx polarized. Although many demonstrated an enlightened standpoint, adopting innovative practices introduced by overseas coaching talent, these views were counter-balanced by evidence of a myopic arrogance bordering on xenophobic resistance to change in what now has to be considered the global rather than the ‘English’ game.  相似文献   
3.
Genetic variation in the angiotensin II type 1 receptor (AT1R) has an important effect on the outcome of acute coronary syndrome (ACS) initiated treatment with captopril. This study aims to investigate the impact of genetic polymorphism of AT1R (rs5186 and rs275651) on the ACS outcome in Iraqi patients treated with captopril. A total of 250 Iraqi individuals with ACS were included in this case—control study and they were divided into two study groups; Study group 1 included 125 participants who were prescribed captopril, 25 mg twice daily and study group 2 included 125 participants who received no captopril as part of their ACS treatment (control study). The AT1R gene (rs5186) CC genotype was found to be associated with ST-elevation myocardial infarction (STEMI) (Odd’s ratio (O.R) = 1.2, P = 0.7), while AC was associated with Non-ST-elevation myocardial infarction (NSTEMI) and unstable angina (UA) (O.R = 1.2, P = 0.8). AC genotype is more prone to have Percutaneous coronary intervention (PCI) after ACS attack (O.R = 1.2, P = 0.6). CC genotype had a risk to get less improvement (O.R = 1.6, P = 0.5), so might require higher doses of captopril during acute coronary insult. The AT1R gene (rs275651) AA genotype was associated with UA (O.R = 1.3, P = 0.9). AA and AT genotypes were more prone to have PCI after ACS attack (O.R = 3.9 P = 0.2, O.R = 3.5, P = 0.3 respectively) and thus requiring higher doses of captopril. We conclude that the AT1R rs5186, rs275651 genetic polymorphisms might partially affect the clinical outcome of ACS patients treated with captopril and might have captopril resistance which requires higher doses.  相似文献   
4.
In this digital ITEMS module, Dr. Jeffrey Harring and Ms. Tessa Johnson introduce the linear mixed effects (LME) model as a flexible general framework for simultaneously modeling continuous repeated measures data with a scientifically defensible function that adequately summarizes both individual change as well as the average response. The module begins with a nontechnical overview of longitudinal data analyses drawing distinctions with cross-sectional analyses in terms of research questions to be addressed. Nuances of longitudinal designs, timing of measurements, and the real possibility of missing data are then discussed. The three interconnected components of the LME model—(1) a model for individual and mean response profiles, (2) a model to characterize the covariation among the time-specific residuals, and (3) a set of models that summarize the extent that individual coefficients vary—are discussed in the context of the set of activities comprising an analysis. Finally, they demonstrate how to estimate the linear mixed effects model within an open-source environment (R). The digital module contains sample R code, diagnostic quiz questions, hands-on activities in R, curated resources, and a glossary.  相似文献   
5.
This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R2 values of >0.85 for all variables excluding deadlift mean velocity (R2 = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.  相似文献   
6.
Abstract

This paper provides a methodology to study the characteristics of the research output from a university department. The faculty publications and their cited references over a 10-year period were used as the basis for this study to identify their publishing patterns and the types of material they are publishing; a core set of journals and other resources they are publishing in and citing over this period; the characteristics of the journals in which they publish and cite; the degree of openness of their publications and their citation advantage; and the age of resources that are referenced.  相似文献   
7.
ABSTRACT

This forum brings together food, (in)security, and communication. The authors participating in this forum center communication as both process and tool for understanding, mitigating, and making meaning of food (in)security. The nine authors together discuss the role of communication in food (in)security, the central challenges for scholars and practitioners working on food (in)security, and the creative possibilities and impacts influencing the future of food (in)security. The forum produces a call for applied scholars to re-imagine communication frameworks in order to make meaningful differences in their communities.  相似文献   
8.
9.
10.
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