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   257篇
  免费   5篇
  国内免费   3篇
教育   200篇
科学研究   34篇
各国文化   2篇
体育   17篇
综合类   1篇
信息传播   11篇
  2023年   1篇
  2022年   4篇
  2021年   6篇
  2020年   11篇
  2019年   8篇
  2018年   15篇
  2017年   18篇
  2016年   7篇
  2015年   9篇
  2014年   12篇
  2013年   47篇
  2012年   18篇
  2011年   9篇
  2010年   11篇
  2009年   10篇
  2008年   11篇
  2007年   7篇
  2006年   7篇
  2005年   4篇
  2004年   7篇
  2003年   8篇
  2002年   5篇
  2001年   3篇
  2000年   7篇
  1999年   3篇
  1998年   4篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1992年   1篇
  1991年   2篇
  1987年   1篇
  1982年   1篇
  1979年   1篇
  1976年   1篇
  1975年   1篇
  1974年   1篇
排序方式: 共有265条查询结果,搜索用时 156 毫秒
81.

The more ambitious an educational innovation, the greater the challenge in scaling up. In this paper, we focus on the scaling up of an ambitious pedagogical practice—mathematics problem solving as a regular feature in the classroom. We adopt a long-term approach to continual professional development (CPD) that began with intensive work with one school before we broadened the programme to four other schools which span the spectrum of schools in Singapore. To evaluate this overall design, we examine the current state of each school’s capacity in sustaining mathematics problem-solving instruction. In particular, we study and report findings on these areas: the readiness of teachers, the instructional materials and supporting structures. Based on the findings, we reflect on our CPD strategies and our theory of action which guided the CPD programme.

  相似文献   
82.
This paper describes our novel retrieval model that is based on contexts of query terms in documents (i.e., document contexts). Our model is novel because it explicitly takes into account of the document contexts instead of implicitly using the document contexts to find query expansion terms. Our model is based on simulating a user making relevance decisions, and it is a hybrid of various existing effective models and techniques. It estimates the relevance decision preference of a document context as the log-odds and uses smoothing techniques as found in language models to solve the problem of zero probabilities. It combines these estimated preferences of document contexts using different types of aggregation operators that comply with different relevance decision principles (e.g., aggregate relevance principle). Our model is evaluated using retrospective experiments (i.e., with full relevance information), because such experiments can (a) reveal the potential of our model, (b) isolate the problems of the model from those of the parameter estimation, (c) provide information about the major factors affecting the retrieval effectiveness of the model, and (d) show that whether the model obeys the probability ranking principle. Our model is promising as its mean average precision is 60–80% in our experiments using different TREC ad hoc English collections and the NTCIR-5 ad hoc Chinese collection. Our experiments showed that (a) the operators that are consistent with aggregate relevance principle were effective in combining the estimated preferences, and (b) that estimating probabilities using the contexts in the relevant documents can produce better retrieval effectiveness than using the entire relevant documents.  相似文献   
83.
This paper presents the trends of searching queries by users from peer-to-peer (P2P) networks over an 18-month period from July 2002 to January 2004. Four data sets of search queries collected from Gnutella were studied to describe the searching trends. Major findings include (1) the percentage of duplicate queries ranging from 34% to 68% of total queries; (2) an increase in non-English queries; (3) an approximately half of searching queries specified for video or audio file types; (4) the stop word “the” accounting for one-third of total stop words; (5) the shift of queries from audio to video; and (6) P2P users demanding for timely entertainment and porn materials. Based on the findings, it is worthwhile for P2P developers to consider (1) system design that allows effective searching using multiple languages; and (2) techniques that eliminate stop words for faster searching.  相似文献   
84.
This paper studies the problem of the stochastic stability and H disturbance attenuation for linear continuous-time time-delay systems that possess randomly Markovian jumping parameters. A delay-dependent sufficient condition on the stochastic stability with given H performance is proposed using the stochastic Lyapunov–Krasovskii stability theory. The conditions are formulated as a set of coupled linear matrix inequalities.  相似文献   
85.
In this study, response to intervention and stability of reading performance of 41 kindergarten children identified as at risk of reading difficulty were evaluated from kindergarten through third grade. All students were assessed in the fall of each academic year to evaluate need for intervention, and students who fell below the 30th percentile on criterion measures received small-group supplemental intervention. Measures included a combination of commercial normative referenced measures and specific skill and construct measures to assess growth or change in reading risk status relative to 30th percentile benchmarks. Results indicated that consistent with the findings of prior research involving students with comparable entry-level performance, the majority of children identified as at risk in the beginning of kindergarten responded early and positively to intervention. On average, absolute performance levels at the end of kindergarten positioned students for trajectories of later reading performance that exceeded the 50th percentile on the majority of measures. Moreover, changes in risk status that occurred early were generally sustained over time. Only oral reading fluency performance failed to exceed the 30th percentile for the majority of students.  相似文献   
86.
OBJECTIVE: This study examined factors that influenced caregiver status for African-American mothers who use crack cocaine but are not receiving drug treatment and participated in an HIV prevention study in North Carolina. METHOD: Caregiver mothers who were living with at least one of their children at intake (n = 257) were compared with non-Caregivers who were separated from all of their children (n = 378). Bivariate analyses and logistic regression were used to compare these mothers at intake on current drug use, risky sex practices, psychological symptoms, victimization, and aggression. RESULTS: Compared with Caregiver mothers, non-Caregivers reported higher frequencies of drug use, risky sex practices, psychological distress, and victimization experiences. Caregiver mothers were more likely than non-Caregiver mothers to have health insurance, but were less likely to have received drug treatment. Logistic regression found that non-Caregiver mothers were significantly more likely than Caregiver mothers to be older, to have been physically abused as children, to trade sex more frequently, to be homeless, and to have no health insurance. Recent crack use, psychological symptoms, and victimization were not significantly related to caregiver status. CONCLUSIONS: Findings that socio-environmental factors were more strongly associated with caregiver status than crack use underscore the importance of contextual issues such as housing, victimization history, and resources in serving maternal crack users. Community outreach and interventions that engage mothers who use drugs and live with their children may be more effective strategies than formal office-based services to link mothers who use crack and their children to needed drug treatment and family and child services.  相似文献   
87.
This study argues that teachers are disempowered and demoralised moral agents. Specifically, it uses a qualitative study of Hong Kong teachers to show that teachers’ agency in the pursuit of the moral goal of education is socially disempowered. The study shows that although teachers are committed to the moral goal of education, the obstacles to attaining this goal result in demoralisation. The difficulties consist of technical disempowerment (deprivation of power over one’s labour) and cognitive disempowerment (deprivation of power to identify the instructional value of teachers’ work), which are induced by managerialist educational reforms and school administration.  相似文献   
88.
In recent years, many academic libraries have started adopting social media by, for example, establishing their own Facebook pages. Our research investigates the current Facebook usage among seven university libraries in Hong Kong. Using a mixed-method research approach, we examined the characteristics of academic libraries Facebook usage and its effectiveness to engage with their patrons, based on online observations and Web content analysis from the publicly available data of the Facebook pages.Our results indicated that most libraries in Hong Kong adopted Facebook as a marketing tool, yet the user engagement level in these pages is low. In addition, we also discovered that communication-related posts and video-type posts can attract the most attention of patrons. Based on these outcomes, we provided some recommendations on the application of Facebook for academic libraries.  相似文献   
89.
The present study extended regulatory focus theory (Idson & Higgins, 2000) to an educational setting and attempted to identify individuals with high motivation after both success and failure feedback. College students in Hong Kong (N = 180) participated in an experiment with a 2 promotion focus (high vs. low) × 2 prevention focus (high vs. low) × 2 feedback (success vs. failure) design. The results showed that after success feedback, the students with promotion focus were more motivated than their counterparts with prevention focus. This pattern was reversed after failure feedback. However, the results failed to show that students high in both regulatory focuses were motivated after success as well as failure feedback. The findings are discussed with reference to the literature on flexibility of regulatory focuses. Practical and theoretical implications of feedback are also discussed.  相似文献   
90.
In December 2019, coronavirus disease 2019 became a pandemic affecting more than 200 countries and territories. Millions of lives are still affected because of mandatory quarantines, which hamstring economies and induce panic. Immunology plays a major role in the modern field of medicine, especially against virulent infectious diseases. In this field, neutralizing antibodies are heavily studied because they reflect the level of infection and individuals'' immune status, which are essential when considering resumption of work, flight travel, and border entry control. More importantly, it also allows evaluating the antiviral vaccine efficacy as vaccines are still known for being the ultimate intervention method to inhibit the rapid spread of virulent infectious diseases. In this Review, we first introduce the host immune response after the infection of SARS-CoV-2 and discuss the latest results using conventional immunoassays. Next, as an enabling platform for detection with sufficient sensitivity while saving analysis time and sample size, the progress of microfluidic-based immunoassays is discussed and compared based on surface modification, microfluidic kinetics, signal output, signal amplification, sample matrix, and the detection of anti-SARS-CoV-2 antibodies. Based on the overall comparison, this Review concludes by proposing the future integration of visual quantitative signals on microfluidic devices as a more suitable approach for general use and large-scale surveillance.  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