全文获取类型
收费全文 | 19418篇 |
免费 | 308篇 |
国内免费 | 186篇 |
专业分类
教育 | 12714篇 |
科学研究 | 2895篇 |
各国文化 | 127篇 |
体育 | 1603篇 |
综合类 | 216篇 |
文化理论 | 128篇 |
信息传播 | 2229篇 |
出版年
2022年 | 134篇 |
2021年 | 244篇 |
2020年 | 294篇 |
2019年 | 360篇 |
2018年 | 478篇 |
2017年 | 427篇 |
2016年 | 432篇 |
2015年 | 372篇 |
2014年 | 514篇 |
2013年 | 2857篇 |
2012年 | 591篇 |
2011年 | 699篇 |
2010年 | 559篇 |
2009年 | 542篇 |
2008年 | 513篇 |
2007年 | 603篇 |
2006年 | 557篇 |
2005年 | 495篇 |
2004年 | 368篇 |
2003年 | 358篇 |
2002年 | 345篇 |
2001年 | 345篇 |
2000年 | 344篇 |
1999年 | 343篇 |
1998年 | 196篇 |
1997年 | 183篇 |
1996年 | 207篇 |
1995年 | 190篇 |
1994年 | 145篇 |
1993年 | 151篇 |
1992年 | 227篇 |
1991年 | 232篇 |
1990年 | 235篇 |
1989年 | 264篇 |
1988年 | 209篇 |
1987年 | 225篇 |
1986年 | 220篇 |
1985年 | 250篇 |
1984年 | 224篇 |
1983年 | 212篇 |
1982年 | 176篇 |
1981年 | 168篇 |
1980年 | 157篇 |
1979年 | 244篇 |
1978年 | 190篇 |
1977年 | 180篇 |
1976年 | 148篇 |
1975年 | 132篇 |
1974年 | 151篇 |
1973年 | 132篇 |
排序方式: 共有10000条查询结果,搜索用时 593 毫秒
1.
Jonathan S. Jones Anna-Lynne R. Adlam Abdelmalek Benattayallah Fraser N. Milton 《Child development》2022,93(3):815-830
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.
中外情报学论文创新性特征研究 总被引:1,自引:0,他引:1
[目的/意义] 综合运用定性与定量相结合的方法对近年中外情报学论文的创新性进行分析和对比,揭示情报学领域研究的创新性特征,发现领域学术论文中创新句内部的知识关系,进行更细粒度的论文创新性分析,为研究领域创新点深层次利用提供条件,同时丰富科技论文创新性监测的途径,促进科学研究创新。[方法/过程] 从句子级创新性识别出发,选取中英文各两种情报学期刊作为样本,采用信息抽取和机器学习的方法,将创新句的抽取从现有的摘要扩展到全文,充分利用句子结构和句法特征识别领域创新内容,探讨近年中外情报学论文在创新对象、主题、类别等方面的特征,并做对比分析,最后通过对自动分类的论文集合进行定性的内容分析,总结归纳出中外情报学论文创新的表达范式。[结果/结论] 从创新的表达来看,中外情报学论文创新句的分布情况基本一致,英文期刊论文创新的表达更丰富。从创新性特征来看,英文情报学期刊论文创新主题较集中,而中文主题多样和分散;具体方法的创新是近年情报学领域的创新热点,而在研究方法上创新不足;中英文情报学期刊论文的创新性特点都反映了应用研究、实证研究的成果较多,而理论创新推动缓慢的趋势。 相似文献
3.
科学数据共享研究现状与展望 总被引:2,自引:0,他引:2
[目的/意义] 分析科学数据共享的研究现状及其发展趋势,为促进国内相关理论研究与实践进展提供参考。[方法/过程] 通过对国内外文献进行梳理和归纳,提炼出与科学数据共享研究相关的三大类主题:科学数据共享发展需求、科学数据管理共享模式与机制和科学数据服务共享度与服务效果,并构建科学数据共享管理分析框架,该框架体现上述三类主题之间的因果关联,强调科学数据共享管理与服务的合理面、重要度、关键性。[结果/结论] 国内外现有研究尚存不足,未来研究在加强实证研究、着眼管理机制完善的同时,还需注重共享服务模式的创新。 相似文献
4.
Fadhaa A. Ghafil Bassim I. Mohammad Hussain S. Al-Janabi Najah R. Hadi Hayder A. Al-Aubaidy 《Indian journal of clinical biochemistry : IJCB》2021,36(1):81
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
5.
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
6.
Megan K. Schraedley Hamilton Bean Sarah E. Dempsey Mohan J. Dutta Kathleen P. Hunt Sonia R. Ivancic 《Journal of Applied Communication Research》2020,48(2):166-185
ABSTRACTThis 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
7.
体育课教学是高等学校体育工作的核心。教学质量的好坏直接影响学生的体质。但是 ,现行的班级体育授课制仍然是沿袭以智力、高考分数为核心 ,方便文化课教学的编班制进行体育课教学 ,这无疑影响学生体质的发展和终身体育思想的形成 ,而且给体育课教学带来许多困难。因此 ,从发展学生体质和培养终身锻炼习惯的实际需要出发 ,打破单纯按智力、分数的分班制是当前高校体育教学工作中亟待解决的问题。 相似文献
8.
论运动技能迁移理论在田径教学中的应用 总被引:2,自引:0,他引:2
田径各项目在技术原理、动作组成、身体素质和运动能力等方面有联系 ,因此在田径教学中 ,技能迁移现象随处可见。就教学中技能迁移现象作分析 ,提出在教学中要注意遵循技能迁移规律的应用。 相似文献
9.
10.