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   4998篇
  免费   127篇
  国内免费   10篇
教育   3492篇
科学研究   385篇
各国文化   116篇
体育   513篇
综合类   3篇
文化理论   49篇
信息传播   577篇
  2023年   25篇
  2022年   49篇
  2021年   83篇
  2020年   178篇
  2019年   237篇
  2018年   275篇
  2017年   268篇
  2016年   284篇
  2015年   192篇
  2014年   230篇
  2013年   1199篇
  2012年   174篇
  2011年   167篇
  2010年   149篇
  2009年   145篇
  2008年   153篇
  2007年   126篇
  2006年   114篇
  2005年   67篇
  2004年   64篇
  2003年   92篇
  2002年   55篇
  2001年   64篇
  2000年   49篇
  1999年   45篇
  1998年   38篇
  1997年   36篇
  1996年   33篇
  1995年   34篇
  1994年   32篇
  1993年   34篇
  1992年   30篇
  1991年   45篇
  1990年   20篇
  1989年   26篇
  1988年   23篇
  1987年   24篇
  1986年   13篇
  1985年   28篇
  1984年   21篇
  1983年   15篇
  1982年   20篇
  1981年   27篇
  1980年   11篇
  1979年   17篇
  1978年   20篇
  1977年   10篇
  1975年   8篇
  1974年   7篇
  1969年   7篇
排序方式: 共有5135条查询结果,搜索用时 750 毫秒
1.
Seventy-nine 3-year olds and their mothers participated in a laboratory-based task to assess maternal hostility. Mothers also reported their behavioral regulation of their child. Seven years later, functional magnetic resonance imaging data were acquired while viewing emotional faces and completing a reward processing task. Maternal hostility predicted more negative amygdala connectivity during exposure to sad relative to neutral faces with frontal and parietal regions as well as more negative left ventral striatal connectivity during monetary gain relative to loss feedback with the right posterior orbital frontal cortex and right inferior frontal gyrus. In contrast, maternal regulation predicted enhanced cingulo-frontal connectivity during monetary gain relative to loss feedback. Results suggest parenting is associated with alterations in emotion and reward processing circuitry 7–8 years later.  相似文献   
2.
In Korean information retrieval, compound nouns play an important role in improving precision in search experiments. There are two major approaches to compound noun indexing in Korean: statistical and linguistic. Each method, however, has its own shortcomings, such as limitations when indexing diverse types of compound nouns, over-generation of compound nouns, and data sparseness in training. In this paper, we propose a corpus-based learning method, which can index diverse types of compound nouns using rules automatically extracted from a large corpus. The automatic learning method is more portable and requires less human effort, although it exhibits a performance level similar to the manual-linguistic approach. We also present a new filtering method to solve the problems of compound noun over-generation and data sparseness.  相似文献   
3.
4.
The goal of the Standards for Educational and Psychological Testing is to improve testing practices, but their impact on practice appears spotty. Self-regulation clearly fails in some instances. The establishment of an external agency to oversee testing practices and adherence to the Standards would face substantial hurdles, and the ambiguity of many of the Standards would hobble such an organization if one were created. Many of the Standards are general statements of principle, and past controversies make clear that we in the field often disagree about the reasons for them, their applicability to specific cases, and their practical meaning in specific contexts. This paper argues that the field should follow two approaches to lessen this ambiguity. First, using journals, conferences, and other vehicles, we should foster more frequent and more protracted debate about the practical meaning of key Standards, such as 13.6 and 13.7, which mandate that a decision that will have a "major impact" on a student should not be based on a single score. Second, future revisions of the Standards should use concrete examples of testing practices to clarify the meaning of the Standards, much as the legal system uses case law to clarify the meaning of the general principles embodied in statutes .  相似文献   
5.
6.
7.
8.
9.
Book reviews     
cAbd al‐Malik b. Habib. Kitāb al‐Ta'rij (La historia). Edición y estudio por Jorge Aguadé. Madrid: Consejo Superior de Investigaciones Científicas & Instituto de Cooperación con el Mundo Arabe, 1991 (Fuentes Arabico‐Hispanas, 1). 163 + 224 pp. [Arabic title: Kltāb al‐Ta'tikh]

Kedar, Benjamin Z., ed. The Horns of Hattin. Jerusalem and London: Yad Izhak Ben‐Zvi, Israel Exploration Society and Variorum 1992. 368 pp., 12 plates; $74.75 (cloth).

Köprülü, Mehmed Fuad. The Seljuks of Anatolia: Their History and Culture According to Local Muslim Sources. Translated and edited by Gary Leiser. Salt Lake City: University of Utah, 1992. xi +101 pp., $22.00 (cloth).

Cameron, Averil and Conrad, Lawrence I., eds. The Byzantine and Early Islamic Near East: Problems in the Literary Source Material (Papers in the First Workshop on Late Antiquity and Early Islam). Princeton: The Darwin Press, 1992. xiv + 428pp., 12 plates; $29.25 (cloth).

Vereno, Ingolf. Studien zum ältesten alchemistischen Schrifttum. Berlin: Klaus Schwarz Verlag, 1992 (Islamkundliche Untersuchungen, 155). 414pp.

Tolan, John. Petrus Alfonsi and his Medieval Readers. Gainesville, Florida: University Press of Florida, 1993. xv + 288pp., $34.95 (cloth), $16.95 (paper).

Lassner, Jacob. Demonizing the Queen of Sheba: Boundaries of Gender and Culture in Postbiblical Judaism and Medieval Islam. Chicago: University of Chicago, 1994. 281 pp., $19.95 (paper), $49.95 (cloth).

Menocal, María Rosa. Shards of Love: Exile and the Origins of the Lyric. Durham, North Carolina: Duke University Press, 1994. xv + 295pp., $34.95 (cloth), $14.95 (paper).

Massignon, Louis. The Passion of al‐Hallāj, Mystic and Martyr of Islam. Translated and edited by Herbert Mason. Abridged edition, Bollingen Series XCVIII. Princeton: Princeton University Press, 1994. xxxi + 293pp.

Viguera Molins, Maria Jesús. El Islam en Aragón. Saragossa: Caja de Ahorros de la Inmaculada, 1995 (Colección “Mariano de Pano y Ruata”, 9), 174 pp., 182 ills. in colour, maps, diagrams, charts etc No price stated.  相似文献   

10.
Millions of Canadians residing in Canada's northern, isolated, rural, and remote communities do not have broadband Internet access. This situation has led to a national “broadband divide.” That is, the deployment of wireline broadband is very limited in Canada's northern, isolated, rural, and remote areas because of the significant expense of installation and maintenance of the wired infrastructure needed to reach dwellings in these locations.Terrestrial broadband wireless technology, on the other hand, does not entail the same kind of physical infrastructure. As a result, there are dramatic changes in how spatial considerations affect the provision of broadband Internet services (BIS) to areas beyond the urban zone. In particular, the spatial question is now focused on assessing the capacity for different technological solutions to reach profitable population bases, and brings to the forefront organizations that are developing non-line-of-sight (NLOS) technologies that would permit wireless Internet access over much greater distances than current solutions.We begin this paper by establishing the importance of broadband connectivity to Canada's northern, isolated, rural, and remote communities. This discussion comments on the role of the Government of Canada in the provision of broadband connectivity to residents of these communities, and outlines the current regulatory issues that govern wireless services and policy formulation.The second part of the paper illustrates the use of geographic information system (GIS) approaches in the study of wireless broadband planning and deployment. Case study findings suggest that GIS applications can make a significant contribution to the analysis of wireless deployment planning, to the understanding of the relationships between wireless signal sources and consumers, and to the spatial configuration of terrestrial wireless broadband networks. We conclude the paper by discussing how the GIS approach employed could be used to inform the public policy process with regard to increasing access to broadband Internet services in all regions of the country, and thereby providing the opportunity for all Canadians, regardless of location, to fully participate in the Information Society.  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