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   1429篇
  免费   29篇
教育   1038篇
科学研究   61篇
各国文化   28篇
体育   177篇
综合类   1篇
文化理论   8篇
信息传播   145篇
  2023年   8篇
  2022年   11篇
  2021年   21篇
  2020年   51篇
  2019年   62篇
  2018年   81篇
  2017年   75篇
  2016年   77篇
  2015年   49篇
  2014年   52篇
  2013年   330篇
  2012年   40篇
  2011年   48篇
  2010年   35篇
  2009年   35篇
  2008年   37篇
  2007年   30篇
  2006年   29篇
  2005年   27篇
  2004年   37篇
  2003年   25篇
  2002年   22篇
  2001年   12篇
  2000年   20篇
  1999年   17篇
  1998年   5篇
  1997年   20篇
  1996年   11篇
  1995年   11篇
  1994年   14篇
  1993年   11篇
  1992年   11篇
  1991年   14篇
  1990年   12篇
  1989年   11篇
  1988年   13篇
  1987年   10篇
  1986年   7篇
  1985年   14篇
  1984年   5篇
  1983年   9篇
  1982年   6篇
  1981年   6篇
  1980年   7篇
  1979年   7篇
  1978年   6篇
  1977年   2篇
  1976年   4篇
  1973年   3篇
  1971年   3篇
排序方式: 共有1458条查询结果,搜索用时 171 毫秒
61.
Few studies have examined the relation between maternal caloric intake during pregnancy and growth in child academic achievement while controlling for important confounding influences. Using data from the National Longitudinal Survey of Youth, the current study examined the effects of reduced prenatal caloric intake on growth in scores on the Peabody Individual Achievement Test from ages 5 to 14. While models controlling for within‐family covariates showed that prenatal caloric intake was associated with lower reading and mathematical achievement at age 5, models controlling for between‐family covariates (such as maternal IQ) and unobserved familial confounders revealed only a statistically significant association between siblings differentially exposed to prenatal caloric intake and mathematical achievement at age 5.  相似文献   
62.
The implementation of science reform must be viewed as a systems-level problem and not just focus on resources for teachers and students. High-capacity instructional leadership is essential for supporting classroom science instruction. Recent reform efforts include a shift from learning about science facts to figuring out scientific phenomena in which students use science practices as they build and apply disciplinary core ideas. We report findings from a research study on professional development (PD) to support instructional leaders' learning about the science practices. After participating in the PD, the instructional leaders' familiarity with and leadership content knowledge of the science practices significantly improved. Initially, principals used their understandings from other disciplines and content neutral visions of classrooms to make sense of science instruction. For example, they initially used their understandings of models and argument from ELA and math to make sense of science classroom instruction. Furthermore, some principals focused on content neutral strategies, like a clear objective. Over the course of the PD workshops, principals took up the language of the science practices in more nuanced and sophisticated ways. Principals' use of the language of the science practices became more frequent and shifted from identifying or defining them to considering quality and implementation in science classrooms. As we design tools to support science, we need to consider instructional leaders as important stakeholders and develop resources to specifically meet their needs. If the science feels too unfamiliar or intimidating, principals may avoid or reframe science reform efforts. Consequently, it is important to leverage instructional leaders' resources from other disciplines and content neutral strategies as bridges for building understanding in science. We argue that the science practices are one potential lever to engage in this work and shift instructional leaders' understandings of science instruction.  相似文献   
63.

Instructional videos are widely used to study teachers’ professional vision. A new technological development in video research is mobile eye-tracking (MET). It has the potential to provide fine-grained insights into teachers’ professional vision in action, but has yet been scarcely employed. We addressed this research gap by using MET video feedback to examine how expert and novice teachers differed in their noticing and weighing of alternative teaching strategies. Expert and novice teachers’ lessons were recorded with MET devices. Then, they commented on what they observe while watching their own teaching videos. Using a mixed methods approach, we found that expert and novice teachers did not differ in the number of classroom events they noticed and alternative teaching strategies they mentioned. However, novice teachers were more critical of their own teaching than expert teachers, particularly when they considered alternative teaching strategies. Practical implications for the field of teacher education are discussed.

  相似文献   
64.
Processes of designing for systemic innovation for sustainable development (SD) through the lens of three long-term case studies are reported. All case studies, which originated from the SLIM (Social Learning for the Integrated Management and Sustainable Use of Water at Catchment Scale) Project, funded within the EU Fifth Framework Program (2001–2004), constitute inquiry pathways that are explored using a critical incident approach. The initial starting conditions for each inquiry pathway are compared; significant pathway dependencies are identified which foster the development of social learning processes locally, but constrain their uptake and embedding across the wider system of interest. In the first case study, in England & Wales, promising developments in the application of social learning approaches to river basin planning over an initial 3-year period were subsequently marginalised, only to resurface towards the end of the 10-year period of study. In the second, South African case study, significant spaces for social learning and innovation in integrated water resources management were opened up over a five year period but closed down again, primarily as the result of lack of policy support by national government. The third, Italian, case study was designed to assess options for adapting to climate change by opening up new learning spaces between researchers, stakeholders and policy makers. A case for investing in local level systemic innovation through social-learning praxis design approaches and in learning processes around well contextualised case-studies is supported. However, concomitant investment by policy makers in social learning as an alternative, but complementary, governance mechanism for systemic innovation for SD is needed.  相似文献   
65.
Knowledge spillover occurs when recipient firms combine the knowledge of an originating firm with other knowledge. When recipient firms combine the originating firm's knowledge with knowledge that is unfamiliar to the originating firm, the recipient firms potentially provide insight to the originating firm on the viability of exploring such knowledge. By mimicking its recipient firms, the originating firm reduces the challenge and uncertainty of exploring unfamiliar knowledge domains. We examine the exploration activities of 87 telecommunications equipment manufacturers over a ten-year time period. We argue that those firms that operate in competitive and dynamic market environments promoting conservative risk-taking behavior will value such uncertainty reduction more highly and thus rely to a greater extent on their recipient firms for guidance on where to explore for new expertise. In contrast, firms in high-growth market environments are more likely to look beyond the activities of recipient firms when exploring new technological domains and rely less on mimicking their recipient firms.  相似文献   
66.
Recent simulations by Chen and Dorfman [Electrophoresis 35, 405–411 (2014)] suggested that “tilting” the electric field with respect to the lattice vectors of a hexagonal post array would lead to a substantial improvement in electrophoretic DNA separations therein. We constructed such an array where the electric field is applied at an angle equidistant between the two lattice vectors. This tilted array leads to (i) baseline resolution of 20 kbp DNA and λ DNA (48.5 kbp) in a 4 mm channel and (ii) measurable separation resolutions for electric fields up to 50 V/cm, both of which are improvements over untilted post arrays of the same post density. The predicted time required to reach a resolution of unity is approximately 5 min, independent of electric field. The separations are more reproducible at higher fields.  相似文献   
67.
BackgroundDespite the well-established health benefits of physical activity (PA) for young people (aged 4–19 years), most do not meet PA guidelines. Policies that support PA in schools may be promising, but their impact on PA behavior is poorly understood. The aim of this systematic review was to ascertain the level and type of evidence reported in the international scientific literature for policies within the school setting that contribute directly or indirectly to increasing PA.MethodsThis systematic review is compliant with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Six databases were searched using key concepts of policy, school, evaluation, and PA. Following title and abstract screening of 2323 studies, 25 progressed to data synthesis. Methodological quality was assessed using standardized tools, and the strength of the evidence of policy impact was described based on pre-determined codes: positive, negative, inconclusive, or untested statistically.ResultsEvidence emerged for 9 policy areas that had a direct or indirect effect on PA within the school setting. These were whole school PA policy, physical education, sport/extracurricular PA, classroom-based PA, active breaks/recess, physical environment, shared use agreements, active school transport, and surveillance. The bulk of the evidence was significantly positive (54%), 27% was inconclusive, 9% was significantly negative, and 11% was untested (due to rounding, some numbers add to 99% or 101%). Frequency of evidence was highest in the primary setting (41%), 34% in the secondary setting, and 24% in primary/secondary combined school settings. By policy area, frequency of evidence was highest for sport/extracurricular PA (35%), 17% for physical education, and 12% for whole school PA policy, with evidence for shared use agreements between schools and local communities rarely reported (2%). Comparing relative strength of evidence, the evidence for shared use agreements, though sparse, was 100% positive, while 60% of the evidence for whole school PA policy, 59% of the evidence for sport/extracurricular PA, 57% of the evidence for physical education, 50% of the evidence for PA in classroom, and 50% of the evidence for active breaks/recess were positive.ConclusionThe current evidence base supports the effectiveness of PA policy actions within the school setting but cautions against a “one-size-fits-all” approach and emphasizes the need to examine policy implementation to maximize translation into practice. Greater clarity regarding terminology, measurement, and methods for evaluation of policy interventions is needed.  相似文献   
68.
ABSTRACT

This article reviews current and historical debates about active, participant citizens and related conceptions of citizenship. In particular it focusses on the prospects for the participation of citizens in the administration of public bodies. It discusses critically the notion of participative citizenship and active citizenship as articulated by Douglas Hurd (when Home Secretary) and also the version contained in the report of the Speaker's Commission on Citizenship. The article then draws upon research conducted for the Volunteer Centre, by the National Foundation for Educational Research and that by Brehony and Deem which is funded by an Economic and Social Research Council Grant (R000 23 1799), on voluntary activity and school governors, respectively. The applicability of the concept of active citizenship to the oversight of schools by school governing bodies is then considered alongside recent work in the United States. The article then considers the constraints upon active citizenship which prevent many governors from participating as much as the role demands and it ends with a reference to the tension between those who see governing bodies as an arena for democratic accountability and the active participation of citizens and those who view them principally as a means by which the local state is weakened and its functions increasingly transferred to the voluntary sector.  相似文献   
69.
The 100 ms ruling for false start disqualification at athletic competitions governed by the International Association of Athletics Federations has been in force since the early 1990s. Throughout this period, there have been marked changes to the rules that govern the disqualification of athletes from sprint events incorporating starts from blocks. This study analysed all available World and European Championship response-time (RT) data from 1999 to 2014 to examine effects of rule changes on competition RT at major championships. The exponentially modified Gaussian distribution was used to model RT and make comparisons relative to athletes’ sex, ruling periods and competition rounds. Revised RT thresholds of 115 ms and 119 ms were identified for men and women, respectively, indicating that the current 100 ms rule could result in some false starts not being detected in competitive athletics. The study proposes that when using existing International Association of Athletics Federations approved systems, the false start detection threshold should be increased and that men and women athletes should have different thresholds because of substantial evidence of a sex-based difference in RT in elite-standard athletes.  相似文献   
70.
This study examines whether teachers find a treatment clearly linked to a functional assessment more acceptable than treatments based on arbitrarily selected reinforcers. We randomly assigned 111 elementary school teachers to 3 experimental conditions. In all conditions, a problem vignette was read that included the same functional assessment summary but varied according to whether the treatment recommendation was linked to the assessment results. A one-way analysis of variance revealed significantly higher pretreatment acceptability ratings and likelihood of use for the treatment linked to assessment. Implications of these results for school-based consultation are discussed.  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