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   256篇
  免费   2篇
教育   180篇
科学研究   11篇
各国文化   4篇
体育   27篇
文化理论   9篇
信息传播   27篇
  2021年   5篇
  2020年   7篇
  2019年   6篇
  2018年   7篇
  2017年   11篇
  2016年   10篇
  2015年   4篇
  2014年   8篇
  2013年   42篇
  2012年   6篇
  2011年   4篇
  2010年   15篇
  2009年   12篇
  2008年   3篇
  2006年   4篇
  2005年   6篇
  2004年   7篇
  2003年   6篇
  2002年   10篇
  2001年   3篇
  2000年   2篇
  1999年   3篇
  1998年   2篇
  1997年   3篇
  1994年   3篇
  1993年   3篇
  1991年   4篇
  1990年   6篇
  1989年   3篇
  1988年   4篇
  1987年   4篇
  1986年   2篇
  1985年   3篇
  1984年   2篇
  1983年   5篇
  1982年   2篇
  1980年   3篇
  1979年   5篇
  1976年   2篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
  1967年   1篇
  1966年   1篇
  1965年   2篇
  1961年   1篇
  1932年   1篇
  1830年   1篇
排序方式: 共有258条查询结果,搜索用时 0 毫秒
11.
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   
12.
The confined flow of red blood cells (RBCs) in microvasculature is essential for oxygen delivery to body tissues and has been extensively investigated in the literature, both in vivo and in vitro. One of the main problems still open in microcirculation is that flow resistance in microcapillaries in vivo is higher than that in vitro. This discrepancy has been attributed to the glycocalyx, a macromolecular layer lining the inner walls of vessels in vivo, but no direct experimental evidence of this hypothesis has been provided so far. Here, we investigate the flow behavior of RBCs in glass microcapillaries coated with a polymer brush (referred to as “hairy” microcapillaries as opposed to “bare” ones with no coating), an experimental model system of the glycocalyx. By high-speed microscopy imaging and image analysis, a velocity reduction of RBCs flowing in hairy microcapillaries as compared to bare ones is indeed found at the same pressure drop. Interestingly, such slowing down is larger than expected from lumen reduction due to the polymer brush and displays an on-off trend with a threshold around 70 nm of polymer brush dry thickness. Above this threshold, the presence of the polymer brush is associated with an increased RBC deformation, and RBC velocity is independent on polymer brush thickness (at the same pressure drop). In conclusion, this work provides direct support to the hypothesis that the glycocalyx is the main factor responsible of the higher flow resistance found in microcapillaries in vivo.  相似文献   
13.
14.
Florida-James G  Donaldson K  Stone V 《Journal of sports sciences》2004,22(10):967-80; discussion 980
Athens sits in a basin approximately 450 km2 in area, surrounded by mountains and open sea. Anthropogenic emissions in conjunction with the topographical and meteorological conditions can result in high air pollution within the city. The pollutants of concern for athletes competing in Athens 2004 appear to be nitrogen dioxide (NO2), ozone and particulate (PM10) pollution. Exposure to elevated ozone concentrations has been reported to give rise to symptoms that include cough, chest pain, difficulty in breathing, headache, eye irritation and a decrease in forced expiratory volume in one second. All of these effects are likely to impact upon performance, and several studies of cyclists suggest this to be the case. In contrast, the impact of ambient concentrations of NO2 appears to be negligible on normal activities, but at high exercise intensities the impact remains unclear. The use of currently available information and models to predict the effect of ozone and other pollutants on elite athletes is problematical, since such models are based upon significantly lower ventilation rates than those achieved by some elite athletes. In addition, it is already known that the response to ozone can vary somewhat between individuals. Since the individuals who will be competing in Athens are physiologically very different to the participants in most published studies, it is difficult to predict individual responses. There is some evidence to indicate that adaptation to the adverse health and performance effects of ozone can occur, so that performance is partially recovered on re-exposure. The adaptation is not seen in all studies and appears to be dependent on several factors, including the initial sensitivity of the individual to ozone. Antioxidant supplementation has also been shown in some studies to partially ameliorate the adverse effects of ozone by counteracting the oxidative stress mechanism associated with this pollutant. Whether this transfers to performance enhancement per se remains unclear at present. Additional research is required to gain a sound understanding of the effects of a complex mixed air pollution exposure on the pulmonary function and performance of athletes exercising at high work intensities.  相似文献   
15.
This article discusses an action research study that involved the design and delivery of an online training course for teachers of Arabic to speakers of other languages in the Gaza Strip (Palestine). Grounded in Freirean pedagogy, the course aimed to respond to the employment needs of university graduates by creating opportunities for online language teaching. The action research study explored the dynamics at play within the online educational environment, to evidence elements that challenged and/or facilitated effective collaboration between trainers and trainees. This article retraces and discusses the processes through which the course moved from didacticism to engaged critical pedagogy.  相似文献   
16.
This study examined the effects of social influences in the lives of an ethnically diverse sample of fifth through eighth grade students with and without learning disabilities (LD) using survey data and academic achievement scores collected in 19 Chicago public schools from 1993–1997. Similarities and differences in student perceptions of school, family, and peer group contexts were examined. In addition, longitudinal data were analyzed using hierarchical linear modeling (HLM) to identify contextual influences on changes in student reading achievement over time. Comparisons of student responses confirm and extend existing findings in the literature concerning the perceptions of students with LD of their social environments. In particular, having a learning disability was associated with consistent, mostly negative, effects on social relations across the contexts of students’ lives, regardless of gender, race, grade, and socioeconomic status. In addition, student perceptions of their friendship groups were found to have small, but significant, effects on their growth in reading achievement over the course of middle school. While students with and without LD had somewhat different views of their social contexts, the processes working within these environments appeared to affect their reading achievement in similar ways. The results suggest that careful attention should be paid to the social contexts of students’ lives when planning academic interventions.  相似文献   
17.
18.
19.
Stone 《学生电脑》2010,2(7):26-26
从Windows系统下最简单的重装系统的方法。 ①打开Ghost XP下载网站。 ②单击打开最新的GhostXP系统下载页面。 ③单击“点这里下载”,下载后将得到一个ISO文件。解压释放GHO文件  相似文献   
20.
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