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   4834篇
  免费   104篇
  国内免费   329篇
教育   2650篇
科学研究   1309篇
各国文化   2篇
体育   243篇
综合类   132篇
文化理论   8篇
信息传播   923篇
  2024年   2篇
  2023年   18篇
  2022年   59篇
  2021年   114篇
  2020年   145篇
  2019年   177篇
  2018年   156篇
  2017年   143篇
  2016年   99篇
  2015年   148篇
  2014年   328篇
  2013年   566篇
  2012年   387篇
  2011年   397篇
  2010年   294篇
  2009年   352篇
  2008年   365篇
  2007年   352篇
  2006年   264篇
  2005年   204篇
  2004年   146篇
  2003年   112篇
  2002年   118篇
  2001年   100篇
  2000年   45篇
  1999年   35篇
  1998年   35篇
  1997年   27篇
  1996年   24篇
  1995年   6篇
  1994年   13篇
  1993年   13篇
  1992年   12篇
  1990年   4篇
  1989年   1篇
  1987年   1篇
  1985年   2篇
  1982年   1篇
  1978年   1篇
  1957年   1篇
排序方式: 共有5267条查询结果,搜索用时 14 毫秒
991.
基于科技金融与生态概念相融合的区域科技金融发展的崭新视角,首先依据生态原理构建科技金融生态系统;其次建立评价体系,基于熵权TOPSIS法对科技金融生态系统发展展开评价分析;最后采用空间自相关分析法,分析2009—2016年我国科技金融生态系统空间演化趋势。研究发现:我国科技金融发展水平较高的省份基本聚集在东部地区,东部与其他地区科技金融发展的差异最显著且该差异逐年递增;总体呈现正向空间自相关性且处于萧条区的省份多;未来可能会形成东部地区辐射扩散、中部地区稳步增长、西部地区差异化发展的空间格局。  相似文献   
992.
效率可分为价值形态效率和非价值形态效率,研究军民融合效率必须从非价值角度或从投入品和产出品价格相对不变情况下的价值角度出发。对国防科技工业军民融合效率风险相关概念、根源等基本问题进行界定,从竞争与垄断、生产规模、分工、多元化等四个方面分析了军民融合资源效率风险的关系和发生机理。为了规避军民融合资源效率风险,需遵循军民融合发展规律,健全融合管理机制,净化军民市场环境。  相似文献   
993.
This article presents a multi-lagged-input based data-driven adaptive iterative learning control (M-DDAILC) method for nonlinear multiple-input-multiple-output (MIMO) systems by virtue of multi-lagged-input iterative dynamic linearization (IDL). The original nonlinear and non-affine MIMO system is equivalently transformed into a linear input-output incremental counterpart without loss of dynamics. The proposed learning law utilizes the desired trajectory to cancel the influence from iteration-by-iteration variations, as well as additional multi-lagged inputs to improve control performance. The developed iterative estimation law is more effective and also makes estimation of the unknown parameters easier because the dynamics for each parameter to represent are decreased by dividing the system into multiple components in the multi-lagged-input IDL formulation. Moreover, the proposed M-DDAILC does not need an explicit and accurate model. It is proved to be iteratively convergent with rigorous analysis. Both a numerical example and a practical application to a permanent magnet linear motor are provided to verify the validity and applicability of the proposed method.  相似文献   
994.
《Research Policy》2019,48(7):1855-1865
Quantitative research evaluation requires measures that are transparent, relatively simple, and free of disciplinary and temporal bias. We document and provide a solution to a hitherto unaddressed temporal bias – citation inflation – which arises from the basic fact that scientific publication is steadily growing at roughly 4% per year. Moreover, because the total production of citations grows by a factor of 2 every 12 years, this means that the real value of a citation depends on when it was produced. Consequently, failing to convert nominal citation values into real citation values produces significant mis-measurement of scientific impact. To address this problem, we develop a citation deflator method, outline the steps to generalize and implement it using the Web of Science portal, and analyze a large set of researchers from biology and physics to demonstrate how two common evaluation metrics – total citations and h-index – can differ by a remarkable amount depending on whether the underlying citation counts are deflated or not. In particular, our results show that the scientific impact of prior generations is likely to be significantly underestimated when citations are not deflated, often by 100% or more of the nominal value. Thus, our study points to the need for a systemic overhaul of the counting methods used evaluating citation impact – especially in the case of researchers, journals, and institutions – which can span several decades and thus several doubling periods.  相似文献   
995.
《Endeavour》2019,43(4):100709
The independence of science was long seen as of prime importance. This position has become less common today. The perception of scientific research as a public service has led to the opinion that it must be accountable to citizens and produce knowledge and innovation that meet their expectations. Numerous authors have voiced the need for anticipatory ethical control of innovation focusing on the scientific research process. This control is considered as the must-have guarantee for “good science.” The current article attempts to trace the ideological origins of the ethical control of innovation, examines its effectiveness against the challenge of globalization and technology-derived major threats and its compatibility with scientific methodology. It also suggests ways to both regulate the innovation process and preserve the independence of science. On the whole, we conclude that truly effective ethical regulation of innovation, i.e. one that protects the greatest number from its adverse effects, is achieved first and foremost by questioning our liberal economic model and the place given to science in our societies.  相似文献   
996.
This article draws attention to literary works which have been influenced by microscopy, or in which microscopy has played a significant role. The work of writers including Jonathan Swift, Voltaire, George Eliot, H. G. Wells and D. H. Lawrence is discussed. In many cases these authors had direct experience of operating microscopes and viewing the wonders of the microscopic world. However, with the increasing separation of the two cultures, recent examples of microscopy in literature are rare.  相似文献   
997.
《西州使程记》是记录北宋初期高昌回鹘社会文化风貌的重要史料。通过对历史文献和文物古迹的双向考证,对《西州使程记》中记载的体育娱乐活动进行研究,在此基础上提出“一带一路”倡议下新疆体育文化的发展启示。结果表明:《西州使程记中》所记载的体育娱乐活动有骑射、射物禳灾、苏幕遮以及优戏。《西州使程记》中的体育娱乐活动,反映出北宋初期高昌回鹘社会具有一定的经济发展水平、体现多元的文化形态以及深受宗教思想影响等特征。研究《西州使程记》中的北宋初期高昌回鹘体育,得到的启示是:“一带一路”倡议背景下,新疆体育文化的发展应避免宗教的干扰;应加强对外沟通和交流;新疆体育文化应当引起学界的更多关注;新疆体育文化的研究需注重文物保护和宣传工作。  相似文献   
998.
科技出版是出版业的重要组成部分,具有专业针对性强,读者群较为特殊等区别于其他出版类别的特点。本文从战略把握,鳊辑人员的培养,建立优良作者资源库,加强与读者的互动.建立畅通有效的反馈渠道,适应市场环境要求、建全营销推广机制几方面分析科技出版工作中打遗精品出版物庄重点注意的问题和采取的措施。  相似文献   
999.
根据资源环境科学专业实践教学特点及对人才培养作用,结合绵阳师范学院资源环境科学专业人才培养的目标和要求,构建课程实践、专业实践、社会实践、综合实践"四位一体"的专业实践教学模式,最后提出资源环境科学专业实践教学改革的方案和需要探索的方向。  相似文献   
1000.
要使学生得到全面发展,既要有知识,又要有文化,既要有能力,又要有素质,就必须坚持科学教育与人文教育相融合,同时也要使学生既要有技术,又要有思想,这就必须加强学生文化人格的培养。本文对文化人格的内涵、文化人格的形成条件、文化人格的培养进行了分析,提出通过文化氛围、自身的学习和认识、教师的教学引导及示范、并通过各种活动培养学生的文化人格。  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