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   434篇
  免费   3篇
  国内免费   1篇
教育   349篇
科学研究   28篇
各国文化   4篇
体育   8篇
文化理论   4篇
信息传播   45篇
  2022年   4篇
  2019年   6篇
  2018年   6篇
  2017年   5篇
  2016年   3篇
  2015年   6篇
  2014年   14篇
  2013年   134篇
  2012年   14篇
  2011年   9篇
  2010年   7篇
  2009年   11篇
  2008年   6篇
  2007年   13篇
  2006年   9篇
  2005年   8篇
  2004年   16篇
  2003年   6篇
  2002年   7篇
  2001年   4篇
  2000年   2篇
  1999年   10篇
  1998年   8篇
  1997年   2篇
  1996年   6篇
  1995年   5篇
  1994年   4篇
  1993年   2篇
  1992年   5篇
  1991年   7篇
  1990年   8篇
  1989年   5篇
  1988年   6篇
  1987年   6篇
  1985年   4篇
  1983年   3篇
  1982年   2篇
  1981年   6篇
  1980年   2篇
  1978年   4篇
  1977年   3篇
  1975年   2篇
  1974年   3篇
  1967年   2篇
  1966年   5篇
  1964年   3篇
  1948年   2篇
  1923年   4篇
  1922年   2篇
  1917年   2篇
排序方式: 共有438条查询结果,搜索用时 15 毫秒
31.
32.
Biodeterioration of Incralac used for the protection of bronze monuments   总被引:2,自引:0,他引:2  
Outdoor bronze sculptures are highly susceptible to corrosion in many environments and organic coatings are widely used for their protection. The purpose of this study was to determine the susceptibility of the commonly used coating Incralac to biodeterioration by microorganisms. A yeast was isolated from a bronze statue treated with Incralac and its ability to degrade Incralac was determined using growth curves, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The organism grew slowly on Incralac in liquid culture, but SEM images demonstrated its ability to adhere to Incralac coated metal. Additionally, the yeast caused a rapid drop in the low frequency impedance of Incralac coated metal that was not observed under sterile conditions, indicating that the organism accelerated deterioration of the coating. The potential for microbial growth to accelerate deterioration of Incralac should be considered when developing a maintenance strategy for the protection of outdoor metal monuments.  相似文献   
33.
34.
35.
36.
Peer mentoring programs are an important component in the strategy to enhance the first year undergraduate experience. The operation of these programs needs to be informed by evidence as to their effectiveness. In this article we report on a six-year study of the development of a peer mentoring program in which feedback is used to improve program implementation. Evidence from surveys of participants in the program shows that this process has significantly enhanced their experiences and that the effects of these benefits have increased throughout the life of the program. Moreover, participation in the program enhanced the leadership, communication, and organizational skills of the peer mentors.  相似文献   
37.
38.
For decades, the HIV epidemic has exacted an enormous toll worldwide. However, trend analyses have discerned significant declines in the overall prevalence of HIV over the last two decades. More recently, advances in biomedical, behavioural, and structural interventions offer considerable promise in the battle against generalised epidemics. Despite advances in the prevention of transmission and new infections, morbidity and mortality of HIV among young people remains a considerable concern for individuals, couples, families, communities, practitioners, and policy-makers around the globe. To accelerate the end of the global HIV epidemic among young people, we must merge existing efficacious interventions with more novel, cost-effective implementation strategies to develop integrated, multi-level combination interventions. The benefits of conceptualising the HIV epidemic more broadly and adopting ecological frameworks for the development of HIV prevention programmes are critical.  相似文献   
39.
How environmental knowledge measures up at a Big Ten university   总被引:1,自引:1,他引:0  
The reported research examines the level of environmental knowledge of Michigan State University students relative to the results of a biannual national study of the environmental knowledge of the general population of the United States. While the university students were found to possess higher levels of environmental knowledge than the general public, the students' overall environmental knowledge, on average, was deficient with only 66% of them receiving a passing grade. The findings suggest a positive correlation between academic level, field of study and environmental knowledge.  相似文献   
40.
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