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   150372篇
  免费   2413篇
  国内免费   979篇
教育   103162篇
科学研究   17898篇
各国文化   2072篇
体育   11266篇
综合类   2093篇
文化理论   1118篇
信息传播   16155篇
  2022年   846篇
  2021年   1713篇
  2020年   2196篇
  2019年   2968篇
  2018年   3308篇
  2017年   3652篇
  2016年   3687篇
  2015年   3259篇
  2014年   4686篇
  2013年   29187篇
  2012年   4660篇
  2011年   5231篇
  2010年   4708篇
  2009年   4831篇
  2008年   4635篇
  2007年   4244篇
  2006年   4427篇
  2005年   4015篇
  2004年   4106篇
  2003年   3318篇
  2002年   3135篇
  2001年   2821篇
  2000年   2144篇
  1999年   1801篇
  1998年   1611篇
  1997年   1614篇
  1996年   1760篇
  1995年   1534篇
  1994年   1514篇
  1993年   1495篇
  1992年   1504篇
  1991年   1398篇
  1990年   1382篇
  1989年   1308篇
  1988年   1168篇
  1987年   1087篇
  1986年   1134篇
  1985年   1393篇
  1984年   1266篇
  1983年   1261篇
  1982年   1244篇
  1981年   1166篇
  1980年   1153篇
  1979年   1219篇
  1978年   1196篇
  1977年   1110篇
  1976年   994篇
  1975年   798篇
  1974年   802篇
  1973年   774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.
Early childhood is a sensitive period for learning and social skill development. The maturation of cerebral regions underlying social processing lays the foundation for later social-emotional competence. This study explored myelin changes in social brain regions and their association with changes in parent-rated social-emotional development in a cohort of 129 children (64 females, 0–36 months, 77 White). Results reveal a steep increase in myelination throughout the social brain in the first 3 years of life that is significantly associated with social-emotional development scores. These findings add knowledge to the emerging picture of social brain development by describing neural underpinnings of human social behavior. They can contribute to identifying age-/stage-appropriate early life factors in this developmental domain.  相似文献   
3.
As medical programs place increasing importance on competency-based training and surgical simulations for residents, anatomy laboratories, and body donation programs find themselves in a position of adapting to changing demands. To better assess the demand for “life-like” cadaveric specimens and evaluate the possible impacts that competency-based medical education could have upon the body donation program of McGill University, Canada, the authors tracked, over the course of the last 10 years, the number of soft-embalmed specimens, along with the number of teaching sessions and the residents enrolled in competency-based programs that are using cadaveric material. The results reveal that the number of soft-embalmed specimens used within residency training increased from 5 in 2009 to 35 in 2019, representing an increase from 6% of bodies to 36.5% of the total number of body donors embalmed in this institution. Correspondingly, the number of annual teaching sessions for residents increased from 19 in 2012 to 116 in 2019. These increases in teaching are correlated with increasing number of residents enrolled in competency-based programs over the last 3 years (Pearson r ranging from 0.9705 to 0.9903, and R2 ranging from 0.9418 to 0.9808). Those results suggest that the new skill-centered curricula which require residents to perform specific tasks within realistic settings, exhibit a growing demand for “life-like” cadaveric specimens. Institutions’ body donation programs must, therefore, adapt to those greater need for cadaveric specimens, which presents many challenges, ranging from the logistical to the ethical.  相似文献   
4.
Research in Higher Education - Given the significant need to increase and diversify graduate enrollments within computing fields, it is vital to understand what shapes students’ pathways to...  相似文献   
5.
[目的/意义]基于版权保护的演化博弈分析,有助于探究数字内容产品的原创主体对仿冒行为是否具有容忍度,以及不同仿冒水平下实施版权保护的策略选择,对规范数字内容产品市场主体行为具有一定指导意义。[方法/过程]首先借助演化博弈模型,分析原创主体与仿冒主体的利益演化过程,探究版权保护下原创主体对仿冒水平的容忍行为;然后通过细化博弈双方的利润函数模型,探究原创主体容忍度水平的决定因素。[结果/结论]原创主体对较小的仿冒水平存在一定的容忍度,对较高的仿冒水平零容忍。最大仿冒水平容忍度由仿冒交叉收益系数、收益模型常系数、产品研发成本系数和原创主体的产品研发努力水平倍数4个因素共同决定。  相似文献   
6.
7.
Abstract

Supporting global health priorities through the development of robust health science librarianship partnerships is of significant importance. Increased demand for synthesizing evidence-based information, collating quality resources, and increasing research productivity to improve human health requires integration of library and information science skills and expertise. The Health Sciences Library (HSL) at the University of North Carolina at Chapel Hill (UNC), exists to be an indispensable partner in health information and knowledge, teaching and learning, and research. As global efforts at UNC expanded, the HSL sought to ensure that our global engagement strategy and integration were aligned with campus priorities and partner needs. The HSL created a global research partnership plan: identify resources that improve efficiency, increase access to information, build in-country capacity and expertise—all while strengthening collaborations across multiple countries. Creating a meaningful and sustainable engagement strategy was central to envisioning our path forward and can be used as a framework for consideration by librarians in similar settings.  相似文献   
8.
[目的/意义]梳理图书馆与区域的关系,不以简单的服务与被服务进行限定,而从两者包含与互动来认识图书馆为区域服务。[方法/过程]图书馆为区域服务应该从环境与定位入手,重新分析认识图书馆社会职责、重点任务、服务工作内容。[结果/结论]图书馆是区域的组成部分,应以主体意识来发展自己,完善区域构成。图书馆应遵循定位,选准重点建设,筑牢专业的服务基础,为区域的政府决策、科研开发、产业经济、民众生活等提供信息服务。  相似文献   
9.
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   
10.
  • Scientific publication has been a key part of the scientific method since the inception of Philosophical Transactions in 1665.
  • The scientific publications industry has grown exponentially along with science, incorporating technological innovations along the way, and adapting journal processes and practices to changing needs of science as it matured.
  • Of all the technological innovations over more than 300 years, the move to online journals may be the most significant, making open access to content practical for the first time.
  • The open‐access movement is disrupting the economics of journal publishing, which is hoped will make the industry more competitive: the ability of the publications industry to adapt to open access will be a measure of its resilience.
  • The demand for articles published in reputable journals continues to grow as readers trust the credibility of peer reviewed journal articles, and good authors value the prestige of publishing in the best journals.
  • It is difficult to predict what new functionalities may be included in articles of the future or what additional services publishers and editors will provide, but there is every reason to believe that scientific journal articles are here to stay.
  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