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   10661篇
  免费   168篇
  国内免费   7篇
教育   7265篇
科学研究   1135篇
各国文化   350篇
体育   807篇
综合类   5篇
文化理论   75篇
信息传播   1199篇
  2022年   77篇
  2021年   122篇
  2020年   177篇
  2019年   269篇
  2018年   317篇
  2017年   342篇
  2016年   298篇
  2015年   214篇
  2014年   238篇
  2013年   1925篇
  2012年   235篇
  2011年   238篇
  2010年   216篇
  2009年   209篇
  2008年   280篇
  2007年   242篇
  2006年   213篇
  2005年   196篇
  2004年   207篇
  2003年   142篇
  2002年   128篇
  2001年   163篇
  2000年   196篇
  1999年   164篇
  1998年   98篇
  1997年   95篇
  1996年   81篇
  1994年   75篇
  1993年   86篇
  1992年   142篇
  1991年   153篇
  1990年   152篇
  1989年   157篇
  1988年   122篇
  1987年   121篇
  1986年   122篇
  1985年   161篇
  1984年   135篇
  1983年   124篇
  1982年   103篇
  1981年   81篇
  1980年   91篇
  1979年   143篇
  1978年   90篇
  1977年   91篇
  1976年   78篇
  1975年   76篇
  1974年   89篇
  1973年   81篇
  1968年   74篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Editorial     
B. Sury 《Resonance》2018,23(7):723-725
  相似文献   
2.
ABSTRACT

This article offers a textual analysis and semiotic reading of the Rich Kids of Tehran's (RKOT’s) Instagram page. Contributing to scholarship on Iranian youth media practices, this article interrogates how the RKOT navigate urban and rural space to engage in everyday processes of resistance against global and local systemic oppression. Grounding their visual representations on Instagram in historical and cultural context, the author questions how and when quotidian actions are transformed into political transgressions when posted on social media. This article emphasizes the RKOT's agency in shaping their brand by analyzing representations of gender performance, intertextuality, and national identity on Instagram.  相似文献   
3.
In the IR field it is clear that the value of a system depends on the cost and benefit profiles of its users. It would seem obvious that different users would prefer different systems. In the TREC-9 filtering track, systems are evaluated by a utility measure specifying a given cost and benefit. However, in the study of decision systems it is known that, in some cases, one system may be unconditionally better than another. In this paper we employ a decision theoretic approach to find conditions under which an Information Filtering (IF) system is unconditionally superior to another for all users regardless of their cost and benefit profiles.It is well known that if two IF systems have equal precision the system with better recall will be preferred by all users. Similarly, with equal recall, better precision is universally preferred. We confirm these known results and discover an unexpected dominance relation in which a system with lower recall will be universally preferred provided its precision is sufficiently higher.  相似文献   
4.
5.
6.
Children with spelling deficits demonstrate significant difficulty using inflectional morphology in their writing. This study investigated whether phonological deficits account for these pronounced difficulties or if they are more accurately explained by limitations in morphological or orthographic awareness. Twenty–six 11—13–year–old children with spelling deficits, 31 younger spelling–level–matched children, and 31 age–matched children were asked to spell a series of verbs with past tense and progressive markers in dictated sentences and in list form. Performance on spelling tasks was compared to performance on phonological, morphological, and orthographic awareness tasks. Results suggest that children with spelling deficits have significant difficulty including inflections as well as spelling inflections and base words. Difficulty was most pronounced in a sentence context. Ability to spell inflectional forms was related to variation in morphological awareness in children with spelling deficits and to variation in orthographic awareness in spelling–level–matched children.  相似文献   
7.
Gordon  R. S.  Franklin  K. L.  Baker  J.  Davies  B. 《Sports Engineering》2004,7(3):131-138
Sports Engineering - A Monark cycle ergometer is a device globally used in physiological studies to measure the work and energy levels of exercising humans. In this paper a rope-braked cycle...  相似文献   
8.
In the cultural heritage area, it is of fundamental importance to characterize and classify the conservation state of the materials constituting ancient monuments, in order to study and monitor their decay. Generally, the decay diagnosis is provided by “naked eye” analysis done by expert scientists “walking around” the artifact and recording the conservation state of each individual element they observe. In this paper, a color image segmentation approach, based on histogram threshold and edge detection techniques is presented, to extract degradation regions, characterized by holes or cavities, from color images of stone-materials. The goal is to provide an aid to the decay diagnosis by segmenting degraded regions from color images, computing quantitative data, such as the area and perimeter of the extracted zones, and processing qualitative information, such as various levels of depth detected into the same zones. Since color is a powerful tool in the distinction between objects, a segmentation technique based on color, instead of intensity only, has been used to provide a clearer discrimination between regions. The study case concerns the impressive remains of the Roman Theatre in the city of Aosta (Italy). In particular, we have processed and analyzed some color images of the theatre puddingstones, acquired by a camera.  相似文献   
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