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   116篇
  免费   5篇
  国内免费   1篇
教育   51篇
科学研究   43篇
各国文化   1篇
体育   3篇
文化理论   1篇
信息传播   23篇
  2023年   6篇
  2022年   1篇
  2021年   5篇
  2020年   5篇
  2019年   7篇
  2018年   15篇
  2017年   10篇
  2016年   6篇
  2015年   3篇
  2014年   11篇
  2013年   18篇
  2012年   7篇
  2011年   4篇
  2010年   2篇
  2009年   4篇
  2008年   2篇
  2007年   4篇
  2006年   5篇
  2005年   5篇
  1994年   1篇
  1973年   1篇
排序方式: 共有122条查询结果,搜索用时 419 毫秒
51.
Sigma is a metric that quantifies the performance of a process as a rate of Defects-Per-Million opportunities. In clinical laboratories, sigma metric analysis is used to assess the performance of laboratory process system. Sigma metric is also used as a quality management strategy for a laboratory process to improve the quality by addressing the errors after identification. The aim of this study is to evaluate the errors in quality control of analytical phase of laboratory system by sigma metric. For this purpose sigma metric analysis was done for analytes using the internal and external quality control as quality indicators. Results of sigma metric analysis were used to identify the gaps and need for modification in the strategy of laboratory quality control procedure. Sigma metric was calculated for quality control program of ten clinical chemistry analytes including glucose, chloride, cholesterol, triglyceride, HDL, albumin, direct bilirubin, total bilirubin, protein and creatinine, at two control levels. To calculate the sigma metric imprecision and bias was calculated with internal and external quality control data, respectively. The minimum acceptable performance was considered as 3 sigma. Westgard sigma rules were applied to customize the quality control procedure. Sigma level was found acceptable (≥3) for glucose (L2), cholesterol, triglyceride, HDL, direct bilirubin and creatinine at both levels of control. For rest of the analytes sigma metric was found <3. The lowest value for sigma was found for chloride (1.1) at L2. The highest value of sigma was found for creatinine (10.1) at L3. HDL was found with the highest sigma values at both control levels (8.8 and 8.0 at L2 and L3, respectively). We conclude that analytes with the sigma value <3 are required strict monitoring and modification in quality control procedure. In this study application of sigma rules provided us the practical solution for improved and focused design of QC procedure.  相似文献   
52.
This article examines the impact of subtractive schooling, including language use in education, on the identity of a group of ethnic minority students in Central Highlands of Vietnam. Drawing on semistructured interview data, a deeper look is taken into the ways in which these students identify themselves with their languages, cultures, and social relations. Findings reveal that the subtractive power of the school language and the institutional milieu profoundly influenced their identity construction by creating the conditions for (a) the devaluation of their language and cultural identity as a consequence of the invasion of their sociocultural territory by the dominant language and culture and (b) the segregation and disunity that affected their identity construction through social relations. Although subtractive schooling apparently facilitated students’ integration into the mainstream, its invisible power forced them not only to integrate but also to bear the full burden of constructing new identities to adjust to the school environment and the mainstream society.  相似文献   
53.
The Urban Review - This article draws from the authors’ inquiry into their experiences in an intergenerational research project—an afterschool youth participatory action research...  相似文献   
54.
The preservation of confidentiality has become a major issue for the majority of applications that process personal information, the sensitivity of this information requires creators to set rules for the sharing and use of access control policies. A great deal of research has already been conducted in educational environments. However, one aspect that has not received much attention is the important role of Information Security, especially in newer education environments such as the e-learning environment. In this article we seek to propose a policy of security in such a way to affect views of profiles for each user to control the information accessed by this user.  相似文献   
55.
56.
57.
This paper reports on an investigation into the representation of teachers in newspapers in five countries. An innovative methodology was used to develop a method of inquiry that supports a deeper understanding of media representations of teachers which can also be used by other researchers in comparative education. The paper explores relevant literature on teachers' work and media studies, and describes the decisions made about the selection of newspapers from the five countries and the analytical framework. Central to the project was the development of an analytic framework which we applied to our analysis of the media data collected from the five countries. The process revealed the construction of four categories of teacher identity: the caring practitioner; the transparent (un)professional; the moral and social role model; and the transformative intellectual. The aim was not to generalise categories but to offer them as they were found in newspapers during this time frame. The data analysis demonstrates the applicability of the innovative methodology while the project also contributes to locally translated understandings of teacher representations. The paper concludes with a reflection on the effectiveness of the methodology for comparative research.  相似文献   
58.
This study evaluated the representations of nature of science (NOS) in U.S. state science standards, and examined the changes in these representations from documents advanced in the 1980s through 2016. Drawing from the consensus perspective on NOS and prior studies focusing on the analysis of textual content, documents were inspected for 10 target NOS aspects: the empirical, tentative, inferential, creative, theory-driven, and social NOS, in addition to the myth of “The Scientific Method,” the nature of scientific theories and laws, and the social and cultural embeddedness of science. Ninety-eight state documents from 48 states were analyzed and multiple editions were collected from 34 states. Additionally, relevant materials from the Next Generation Science Standards (NGSS) were assessed for their coverage of the same NOS aspects. Collected materials were scored as whole documents, including over 11,000 pages of text in total, on each target aspect, which reflected the treatment (naïve vs. informed) of NOS in text and the manner of presentation (explicit vs. implicit). Overall, surprisingly, state standards documents have improved very little with respect to their NOS coverage over the last 30 years. NOS standards documents remain silent on a majority of key aspects of NOS, and the number of aspects showing explicit, informed representations has held constant. The NGSS performed well compared to many contemporary documents, but they failed to address all target NOS aspects in a desirable manner. Further analysis raised concerns with the degree that states fully adopt and disseminate standards in manner consistent with the NGSS despite stated intentions, which may negatively impact NOS coverage in instructional resources and classroom enactments. To improve NOS representations in standards, recognizing the role these documents play in shaping instructional materials and teaching in the science classroom, exemplars from analyzed materials were highlighted with informed and explicit representations of multiple aspects.  相似文献   
59.
Active Noise Control (ANC) systems are increasingly used to reduce environmental noises. A hybrid ANC system is a combination of feedforward and feedback structures in which the anti-noise signal is generated using both structures. Employing the advantages of feedforward and feedback structures enables a hybrid structure to have a high performance in controlling unwanted noise. The step size of filters used in ANC systems plays an essential role in its performance. Any variation from the appropriate value leads to divergence or inefficiency of the noise controller system. These parameters are often set experimentally, which is a time-consuming task. In addition, there is no guarantee that the system can adapt itself to situational changes. The objective of this paper is to propose a new self-tuning hybrid ANC method. Using this technique, the system continuously estimates the parameters during its operation. Results of computer simulations demonstrate the robustness of the proposed method.  相似文献   
60.
The aim of this study was to investigate the effects of maturation on power and sprint performance adaptations following 6 weeks of plyometric training in youth soccer players during pre-season. Sixty male soccer players were categorized into 3 maturity groups (Pre, Mid and Post peak height velocity [PHV]) and then randomly assigned to plyometric group and control group. Vertical jump, standing long jump, and 20-m sprint (with and without ball) tests were collected before- and after-intervention. After the intervention, the Pre, Mid and Post-PHV groups showed significant (P ≤ 0.05) and small to moderate effect size (ES) improvement in vertical jump (ES = 0.48; 0.57; 0.73), peak power output (E = 0.60; 0.64; 0.76), standing long jump (ES = 0.62; 0.65; 0.7), 20-m sprint (ES = ?0.58; ?0.66), and 20-m sprint with ball (ES = ?0.44; ?0.8; ?0.55) performances. The Post-PHV soccer players indicated greater gains than Pre-PHV in vertical jump and sprint performance after training (P ≤ 0.05). Short-term plyometric training had positive effects on sprinting and jumping-power which are important determinants of match-winning actions in soccer. These results indicate that a sixty foot contact, twice per week program, seems effective in improving power and sprint performance in youth soccer players.  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