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   3889篇
  免费   44篇
  国内免费   3篇
教育   2733篇
科学研究   388篇
各国文化   80篇
体育   242篇
综合类   2篇
文化理论   48篇
信息传播   443篇
  2021年   29篇
  2020年   40篇
  2019年   61篇
  2018年   93篇
  2017年   92篇
  2016年   108篇
  2015年   58篇
  2014年   72篇
  2013年   1085篇
  2012年   57篇
  2011年   68篇
  2010年   57篇
  2009年   80篇
  2008年   75篇
  2007年   58篇
  2006年   78篇
  2005年   45篇
  2004年   57篇
  2003年   55篇
  2002年   50篇
  2001年   52篇
  2000年   57篇
  1999年   37篇
  1998年   42篇
  1997年   33篇
  1996年   41篇
  1995年   57篇
  1994年   46篇
  1993年   44篇
  1992年   61篇
  1991年   46篇
  1990年   44篇
  1989年   38篇
  1988年   41篇
  1987年   46篇
  1986年   40篇
  1985年   55篇
  1984年   42篇
  1983年   33篇
  1982年   60篇
  1981年   31篇
  1980年   40篇
  1979年   40篇
  1978年   33篇
  1977年   23篇
  1976年   37篇
  1975年   32篇
  1974年   26篇
  1973年   16篇
  1970年   14篇
排序方式: 共有3936条查询结果,搜索用时 20 毫秒
1.
ABSTRACT

This study operationalized Weick’s [(1988). Enacted sensemaking in crisis situations. Journal of Management Studies 25(4), 305–317 and (1993). The collapse of sensemaking in organizations: The Mann Gulch disaster. Administrative Science Quarterly, 38, 628–652] theory of enacted sensemaking to examine the communication processes associated with the Flint Water Crisis of 2014–2015. A content analysis of 389 emails and attachments from a total population of N?=?37,376 pages of publicly released e-mails and documents pertaining to Flint’s water issues, identified examples of failed sensemaking by government officials. These failures hastened and intensified a growing crisis of lead contamination and an outbreak of Legionnaires disease associated with Flint’s municipal water system. Analysis of email messages suggests that strong commitments by top leaders and limited capacity were important factors as were efforts to create and maintain consensus among officials. The Flint Water Crisis offers an important application of sensemaking theory and its utility for both organizational and risk communication scholars and for practical application. The authors emphasize the importance of questioning previous assumptions and commitments, insuring that communication practitioners are involved in decisions, and avoiding over reliance on image repair as a strategic response.  相似文献   
2.
ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.  相似文献   
3.
Whether and to what extent kindergarten children's executive functions (EF) constitute promising targets of early intervention is currently unclear. This study examined whether kindergarten children's EF predicted their second-grade academic achievement and behavior. This was done using (a) a longitudinal and nationally representative sample (N = 8,920, Mage = 97.6 months), (b) multiple measures of EF, academic achievement, and behavior, and (c) extensive statistical control including for domain-specific and domain-general lagged dependent variables. All three measures of EF—working memory, cognitive flexibility, and inhibitory control—positively and significantly predicted reading, mathematics, and science achievement. In addition, inhibitory control negatively predicted both externalizing and internalizing problem behaviors. Children's EF constitute promising targets of experimentally evaluated interventions for increasing academic and behavioral functioning.  相似文献   
4.
In a recent article in this Journal, Eric Moore criticized an earlier essay of mine published in this same Journal on two fronts. On the first, he criticized my criticisms of broad internalism for relying on abstract moral principles too far removed from the practice of sport to adjudicate normative conflicts in which disputants cannot agree on what is the purpose of sport. On the second front, he criticized my reliance on what he called Rorty’s “controversial” views of truth and rationality to back up my criticisms of broad internalism. I find both criticisms forceful but not persuasive. In my reply, therefore, I defend both use of Rorty’s and other similar historicist takes on rational justification and my criticisms of broad internalism principles-based approach to normative inquiry in sport.  相似文献   
5.
6.
This study addresses measurement issues around a standards-based content analysis of mathematics textbooks’ coverage of standards for use in large-scale monitoring of standards implementation as proposed in a 2013 report by the National Research Council. An earlier study produced an exhaustive content analysis of textbooks using the 2012 Common Core State Standards for Mathematics. This yielded an accurate and reliable portrait of a textbook's coverage of standards. However, such an in-depth analysis is not feasible for large-scale standards-implementation monitoring in which a large number of textbooks may need to be analyzed. To provide such a portrait with sufficient accuracy while also substantially reducing the associated resources needed to produce such a portrait, a simulation study was conducted with the exhaustively coded database to compare different sampling schemes. Results indicated that sampling 1 day from each week and coding the corresponding lessons led to sufficiently accurate representations of the overall content of the textbook. The results provide empirical evidence for large-scale standards-based content analyses of mathematics textbooks for monitoring standards implementation which could be adapted for other subject areas.  相似文献   
7.
Utilising the oral language of a principal leading an inner-city at-risk elementary school in a large urban school district in the southwestern USA, the researchers tested behavioural integrity and the dimensions of source credibility (competence, goodwill, and trustworthiness) as antecedents to Motivating Language Theory and the ML Model. Teacher perception data at the Title I elementary school was used for this quantitative study. Over 95% of the teachers responded to a survey each year for a three-year period. Each year, there were statistically significant correlations between each of the antecedents and motivating language. The antecedents accounted for 66–75% of the total variance for motivating language depending on the year based on regression analysis. The results of this study extend the field of Motivating Language Theory and the ML Model, and further explain how the work of principals is accomplished.  相似文献   
8.
9.
Knowledge discovery systems can be traced back to their origin, artificial intelligence and expert systems, but use the modern technique of data mining for the knowledge discovery process. To that end, the technical community views data mining as one step in the knowledge discovery process, while the non-technical community seems to view it as encompassing all of the steps to knowledge discovery. In this exploratory study, we look at medical knowledge discovery systems (MKDSs) by first looking at three examples of expert systems to generate medical knowledge. We then expand on the use of data abstraction as a pre-processing step in the comprehensive task of medical knowledge discovery. Next, we look at how performance of a medical knowledge discovery system is measured. Finally, the conclusions point to a bright future for MKDSs, but an area that needs extensive development to reach its full potential.  相似文献   
10.
Federal legislation requires that research produced with federal funding be available to the public under the Freedom of Information Act. I raise a concern that this power might be used to harass scientists. The goal of data sharing, however, is important, and should be facilitated through electronic data archiving.  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