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   22891篇
  免费   398篇
  国内免费   15篇
教育   16368篇
科学研究   2029篇
各国文化   218篇
体育   1900篇
综合类   13篇
文化理论   175篇
信息传播   2601篇
  2022年   170篇
  2021年   261篇
  2020年   382篇
  2019年   603篇
  2018年   827篇
  2017年   802篇
  2016年   700篇
  2015年   420篇
  2014年   658篇
  2013年   4433篇
  2012年   636篇
  2011年   646篇
  2010年   478篇
  2009年   484篇
  2008年   540篇
  2007年   482篇
  2006年   428篇
  2005年   408篇
  2004年   367篇
  2003年   358篇
  2002年   343篇
  2001年   475篇
  2000年   393篇
  1999年   359篇
  1998年   203篇
  1997年   210篇
  1996年   240篇
  1995年   235篇
  1994年   182篇
  1993年   200篇
  1992年   321篇
  1991年   298篇
  1990年   298篇
  1989年   298篇
  1988年   255篇
  1987年   301篇
  1986年   265篇
  1985年   304篇
  1984年   246篇
  1983年   212篇
  1982年   190篇
  1981年   163篇
  1980年   153篇
  1979年   258篇
  1978年   182篇
  1977年   168篇
  1976年   153篇
  1975年   141篇
  1974年   147篇
  1971年   140篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
Le Centre International de la Photographie publie depuis deux ans un bulletin, lien entre les adhérents de cet organisme et en même temps source de documentation. C'est ainsi que sont édités, en feuilles perforées entrant dans une reliure mobile, les travaux du Centre. Est également réalisée une bibliographie analytique des ouvrages sur la photographie paraissant par fascicules. Mais il est intéressant de souligner deux nouvelles initiatives du C.I.P. que les circonstances et le nombre de demandes et de suggestions qui lui étaient faites I'incitaient à étudier depuis quelque temps déjà.  相似文献   
192.
In recent years, many U.S. states have introduced growth models as part of their educational accountability systems. Although the validity of growth‐based accountability models has been evaluated for the general population, the impact of those models for English language learner (ELL) students, a growing segment of the student population, has not received sufficient attention. We evaluated three commonly used growth models: value tables or transition matrices, projection models, and student growth percentiles (SGP). The value table model identified more ELL students as on track to proficiency, but with lower accuracy for ELL students. The projection and SGP models were more accurate overall, but classified the fewest ELL students as on track and were less likely to identify ELL students who would later be proficient. We found that each model had significant trade‐offs in terms of the decisions made for ELL students. These findings should be replicated in additional state contexts and considered in the development of future growth‐based accountability policies.  相似文献   
193.
194.
We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel, and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the or-thopyroxenes have high XMg and A12O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2 densities of the order of 0.86-0.88 g/cm3. Based on prelim  相似文献   
195.
This paper considers the history of the emergence and development of cooperative cataloging in Russia and abroad and presents the first projects and programs in the field of cooperative cataloging: CONSER, NACO, BIBCO, and PCC. It elucidates the activity of the OCLC Center and Consortium of European Scientific Libraries, which are the first-rate international cooperative associations, as well as the ARBIKON Association and LIBNET centers which are Russian centers of cooperative cataloging.  相似文献   
196.
The analysis results for the basic indicators of innovative activities in the All-Russian Institute for Scientific and Technical Information (VINITI), Russian Academy of Science, are given. Suggestions for optimization are provided and the plan of innovative activities of VINITI is drawn on the basis on the analysis results, which is aimed at the further development of the institute.  相似文献   
197.
Viewing a hostile media bias against one’s group (e.g., political party) is a perceptual effect of media use. When it comes to the portrayal of political parties in the United States, prior research suggests that both Democrats and Republicans see mainstream media coverage as favoring the other side, regardless of the orientation of the political news coverage. Although prior research has not identified all factors that make this perceptual bias more likely, or at explaining how or why this perceptual effect occurs, we do know that it is related to one’s group identity. In this study, we examined salient predictors of hostile media bias during the 2012 presidential campaign. Individual (i.e., political cynicism) and group identity related (i.e., group status, intergroup bias, political ideology) differences of media users predicted such perceptions. But, the medium selected for political information about the campaign also mattered. The use of two media in particular—TV and social networking sites—appear to have blunted hostile media bias perceptions, whereas the use of two other media—radio and video sharing sites—appear to have accentuated perceptions that the media were biased against one’s party  相似文献   
198.
There is a crisis of valuation practices in the current academic life sciences, triggered by unsustainable growth and “hyper-competition.” Quantitative metrics in evaluating researchers are seen as replacing deeper considerations of the quality and novelty of work, as well as substantive care for the societal implications of research. Junior researchers are frequently mentioned as those most strongly affected by these dynamics. However, their own perceptions of these issues are much less frequently considered. This paper aims at contributing to a better understanding of the interplay between how research is valued and how young researchers learn to live, work and produce knowledge within academia. We thus analyze how PhD students and postdocs in the Austrian life sciences ascribe worth to people, objects and practices as they talk about their own present and future lives in research. We draw on literature from the field of valuation studies and its interest in how actors refer to different forms of valuation to account for their actions. We explore how young researchers are socialized into different valuation practices in different stages of their growing into science. Introducing the concept of “regimes of valuation” we show that PhD students relate to a wider evaluative repertoire while postdocs base their decisions on one dominant regime of valuing research. In conclusion, we discuss the implications of these findings for the epistemic and social development of the life sciences, and for other scientific fields.  相似文献   
199.
The present study examines how language use (e.g., personalized vs. depersonalized language) and modality (e.g., tweets vs. Facebook status updates) influence source credibility interdependently. A total of 257 participants read personalized or depersonalized health messages embedded in mock-up tweets or Facebook status updates. The results show that users perceive depersonalized tweets as more credible than depersonalized status updates posted on Facebook. On the other hand, personalized status updates on Facebook generate higher credibility judgments than personalized tweets. The findings are discussed in light of the MAIN model as well as the preconceived user expectations and communication norms of social media.  相似文献   
200.
This study investigated the degree to which religious pluralistic language varies as a function of the intergroup salience of a context and religious orientation. Based on a 2 (Religious Salience of Context) × 3 (Religious Salience of Topic) experimental design, participants (N = 239) were instructed to compose an e-mail to an interactional partner based on the randomly assigned condition. Messages were coded for religious pluralistic language, and participants completed measures of religious orientation and evaluations of the conversational partner. Modest effects were found for both intergroup salience of the context and topic as well as religious orientation.  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