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   753篇
  免费   7篇
教育   513篇
科学研究   52篇
各国文化   6篇
体育   104篇
综合类   1篇
文化理论   11篇
信息传播   73篇
  2023年   4篇
  2022年   16篇
  2021年   25篇
  2020年   27篇
  2019年   41篇
  2018年   53篇
  2017年   48篇
  2016年   47篇
  2015年   27篇
  2014年   41篇
  2013年   124篇
  2012年   32篇
  2011年   32篇
  2010年   20篇
  2009年   14篇
  2008年   13篇
  2007年   15篇
  2006年   10篇
  2005年   17篇
  2004年   14篇
  2003年   13篇
  2002年   7篇
  2001年   6篇
  2000年   4篇
  1999年   4篇
  1998年   9篇
  1997年   3篇
  1996年   11篇
  1995年   7篇
  1994年   5篇
  1993年   2篇
  1992年   6篇
  1991年   6篇
  1990年   6篇
  1989年   4篇
  1988年   4篇
  1986年   3篇
  1985年   3篇
  1984年   7篇
  1983年   4篇
  1982年   7篇
  1981年   3篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1976年   1篇
  1975年   2篇
  1973年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有760条查询结果,搜索用时 0 毫秒
51.
Distributed systems consist of interconnected, lower-dimensional subsystems. For such systems, distributed analysis and design present several advantages, such as modularity, easier analysis and design, and reduced computational complexity. A special case of distributed systems is when the subsystems are connected in a string. Applications include distributed process control, traffic and communication networks, irrigation systems, hydropower valleys, etc. By exploiting such a structure, in this paper, we propose conditions for the distributed stability analysis of Takagi–Sugeno fuzzy systems connected in a string. These conditions are also extended to observer and controller design and illustrated on numerical examples.  相似文献   
52.
This study aimed to analyse the effect of growth during a summer break on biomechanical profile of talented swimmers. Twenty-five young swimmers (12 boys and 13 girls) undertook several anthropometric and biomechanical tests at the end of the 2011–2012 season (pre-test) and 10 weeks later at the beginning of the 2012–2013 season (post-test). Height, arm span, hand surface area, and foot surface area were collected as anthropometric parameters, while stroke frequency, stroke length, stroke index, propelling efficiency, active drag, and active drag coefficient were considered as biomechanical variables. The mean swimming velocity during an all-out 25 m front crawl effort was used as the performance outcome. After the 10-week break, the swimmers were taller with an increased arm span, hand, and foot areas. Increases in stroke length, stroke index, propelling efficiency, and performance were also observed. Conversely, the stroke frequency, active drag, and drag coefficient remained unchanged. When controlling the effect of growth, no significant variation was determined on the biomechanical variables. The performance presented high associations with biomechanical and anthropometric parameters at pre-test and post-test, respectively. The results show that young talented swimmers still present biomechanical improvements after a 10-week break, which are mainly explained by their normal growth.  相似文献   
53.
54.
Background:Developing appropriate concussion prevention and management paradigms in middle school(MS)settings requires understanding parents’general levels of concussion-related knowledge and attitudes.This study examined factors associated with concussion-symptom knowledge and care-seeking attitudes among parents of MS children(aged 10-15 years).Methods:A panel of 1224 randomly selected U.S.residents,aged ≥18 years and identifying as parents of MS children,completed an online questionnaire capturing parental and child characteristics.The parents’concussion-symptom knowledge was measured using 25 questions,with possible answers being“yes”,“maybe”,and“no”.Correct answers earned 2 points,“maybe”answers earned 1 point,and incorrect answers earned 0 point(range:0-50;higher scores=better knowledge).Concussion care-seeking attitudes were also collected using five 7-point scale items(range:5-35;higher scores=more positive attitudes).Multivariable ordinal logistic regression models identified predictors of higher scores.Models met proportional odds assumptions.Adjusted odds ratios(aORs)with 95%confidence intervals(95%CIs)(excluding 1.00)were deemed statistically significant.Results:Median scores were 39(interquartile range:32-44)for symptom knowledge and 32(interquartile range:28-35)for care-seeking attitude.In multivariable models,odds of better symptom knowledge were higher in women vs.men(aOR=2.28;95%CI:1.71-3.05),white/non-Hispanics vs.other racial or ethnic groups(aOR=1.88;95%CI:1.42-2.49),higher parental age(10-year-increase aOR=1.47;95%CI:1.26-1.71),and greater competitiveness(10%-scale-increase aOR=1.24;95%CI:1.13-1.36).Odds of more positive care-seeking attitudes were higher in white/non-Hispanics vs.other racial or ethnic groups(aOR=1.45;95%CI:1.06-1.99)and in older parental age(10-year-increase aOR=1.24;95%CI:1.05-1.47).Conclusion:Characteristics of middle school children’s parents(e.g.,sex,race or ethnicity,age)are associated with their concussion-symptom knowledge and care-seeking attitudes.Parents’variations in concussion knowledge and attitudes warrant tailored concussion education and prevention.  相似文献   
55.
56.
Virtual microscopy (VM) is a widely used teaching method in Medical Education in many developed countries. In Brazil, however, this is not the case for most medical schools, considering Brazilian social inequality and uneven access to technology. Recently, the Covid-19 pandemic has also challenged Universities to seek and make a transition toward more effective methods of full-time online education. Thus, the main goal of this work was to verify student's perception and academic performance, assessed upon VM implementation in a Brazilian Medical School. Ribeirao Preto Medical School students answered a 26-question survey with regards to optical microscopy (OM) and VM. Academic performance was compared between participants that were (year of 2019) or were not (year of 2015) exposed to VM. Taken the results together, subjective impressions such as handling, suitability, learning effectiveness, and pleasure using the tools, have shown a higher score for virtual microscopy (median = 29), when compared to optical microscopy (median = 24) with a P-value < 0.001 by Wilcoxon rank test, upon measurement using an ordinal scale. Regarding academic performance, no statistically significant differences were found between groups (P-value = 0.38, Cohen's d = 0.19). Therefore, VM proved to be adequate to the Brazilian medical education in light of Brazilian social contexts and Covid-19 pandemic.  相似文献   
57.
Substitution of slate roofing tiles is a conventional operation during building restoration, since tiles are very difficult to restore or clean because of the high degree of alteration they suffer. Criteria for replacement of historical building stones must be based on geological, geotechnical and esthetic parameters, among which color is of great importance. In this sense, this paper constitutes a comprehensive and useful colorimetric study of roofing slates from the Iberian Peninsula, for the purposes of restoration. The color of 50 commercial varieties of roofing slate mined in quarries from the 12 mining districts in the Iberian Peninsula was analyzed with a spectrophotometer device, by considering the CIELAB color space. The results of the study were used to develop a protocol for characterizing the color of roofing slate and to define the color range of roofing slate from the Iberian Peninsula. In addition, the similarities and differences in the color and microstructure of the different commercial varieties of Iberian roofing slate were established and the limit of acceptability of replacement of one type of slate by another was determined. Parameter hab was found to be the most important CIELAB color coordinate as regards the formation of homogeneous color groups, and the specular component excluded (SCE) mode was most sensitive as regards detecting color differences between two samples.  相似文献   
58.
The old urban centres are marks of an historical and architectural heritage that should be protected and safeguarded. For such, it is fundamental to have a complete understanding of the genesis, regarding both building and the urban mesh. This fact is essential to the support of qualified, conscientious and sustainable rehabilitation interventions on the old building stock. The research carried out addresses the issue of the old urban centres from the perspective of the analysis and inventory of buildings features. The cataloguing process of the building typologies is presented in this work as a synthesis of the principal construction forms, with the old city centre of Seixal being used as a case study. The identification of building typologies has supported a seismic and fire vulnerability assessment of the old building stock. The assessment methodologies developed and used are based on the detailed survey and building inspection, therefore the building typology cataloguing is essential in the analysis at such a large scale. Then we discussed the strategy for the conservation actions incorporated in a broader risk management policy.  相似文献   
59.
José Castro Silva, lecturer in sciences of education, and José Morgado, assistant professor, both work at the Instituto Superior de Psicologica Aplicada in Lisboa, Portugal. In this article, they describe their study of support teachers' beliefs about the academic achievement of school students with special educational needs. The 'support teachers' who were the subject of this study work in mainstream schools where the majority of pupils with special educational needs are educated in mainstream classes run by 'general teachers'. The work of the support teachers is supervised and supported by 'special education team co-ordinators'. The study reported here set out to elicit the support teachers' beliefs about the factors that contribute to success at school for pupils with special educational needs. Results suggest that the support teachers consider that factors including 'school climate', 'curriculum design' and 'teaching approach' contribute significantly to achievements among these pupils. On the other hand, analysis reveals that the support teachers attribute difficulties and lack of achievement significantly to 'out-of-school' contextual variables. These findings are related to a detailed review of the literature and the authors discuss the implications for policy, practice and professional development.  相似文献   
60.
In this study, the socio-cultural variation in reading comprehension development was examined in 331 fifth graders from schools in Lima, Peru. Reading comprehension was measured using an adaptation of the PIRLS Reading Literacy test. The fifth graders?? reading comprehension results, measured over the course of fifth grade, were related to the development of word decoding, vocabulary, and motivation for reading. Children??s development in these domains was related to their gender, intellectual maturity, home literacy climate, and socio-economic status. Structural Equation Modelling showed that the development of reading comprehension was influenced by the children??s ability to decode words, their vocabulary, and reading motivation. Furthermore, gender and intellectual maturity as well as children??s home literacy climate and socio-economic status appeared to substantially predict reading comprehension development, directly or indirectly. More than half of the variance in reading comprehension by the end of the fifth grade could be explained based on these predictor variables.  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