全文获取类型
收费全文 | 108篇 |
免费 | 3篇 |
国内免费 | 19篇 |
专业分类
教育 | 67篇 |
科学研究 | 54篇 |
体育 | 1篇 |
综合类 | 2篇 |
文化理论 | 2篇 |
信息传播 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2019年 | 2篇 |
2015年 | 4篇 |
2014年 | 12篇 |
2013年 | 8篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 14篇 |
2006年 | 9篇 |
2005年 | 10篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 15 毫秒
71.
对冷轧机工作辊滚动轴承寿命降低的原因进行了分析。结果表明,其工作转速高,引起轴承温升过谪,从面导致轴承烧损。采用喷油润滑或油气润滑,改善轴承润滑与冷却条件, 提高轴承使用寿命。 相似文献
72.
当代绘画是美术专业学生学习内容的重要组成部分,但在教学中学生往往出现知识片面、理论薄弱、表现语言匮乏等现象,因此引导学生对当代绘画的理解认识是一个长期的、深入的过程,教师应该在教学过程中尽量让学生多接触和理解当代绘画,这对启发学生创造性思维、提高绘画技巧、形成个人风格有重要的作用。 相似文献
73.
乌江文人文学,尤其是中上游的乌江文人文学,是伴随着乌江盐油古道的兴起而产生的,它是乌江航运兴旺与外来文化进入融合成的产物,也是灿烂的乌江文化的有机组成部分。对其进行认真研究,将对乌江文人以后的文学创作产生深远影响。 相似文献
74.
西方油画的发展已经有几百年的历史,然而对其的赏析方法却与国画有很大的差异。文章首先探讨了西方油画作品的流派,然后从西方油画的构成——笔触和色彩两个方面探讨了其美学赏析方法,最后从油画的灵魂——意境方面讨论西方油画的美学赏析。 相似文献
75.
土壤石油污染对两种藜科植物幼苗生长的影响 总被引:2,自引:0,他引:2
在实验室人工控制条件下,研究了不同浓度土壤石油污染对两种藜科植物幼苗生长的影响。实验结果表明:土壤石油污染质量分数为500—5000mg/kg时,对碱蓬幼苗株高的生长有一定的促进作用,土壤石油污染质量分数在15000~30000mg/kg时有显著的抑制作用;任何浓度的土壤石油污染都会抑制翅碱蓬幼苗株高的生长,随着石油浓度的逐级增加,抑制作用逐级增大。 相似文献
76.
本文以国际原油价格为主线,采用回归分析工具构建油价供需模型,从供需因素着手,定量分析国际原油价格影响因素和形成机制,并提出在未来全球能源供需格局变化的背景下我国的战略选择。 相似文献
77.
Stephen Klassen 《Science & Education》2009,18(5):593-607
The Millikan oil drop experiment has been characterized as one of the ‘most beautiful’ physics experiments of all time and,
certainly, as one of the most frustrating of all the exercises in the undergraduate physics laboratory. A literature review
reveals that work done on addressing student difficulties in performing the oil drop experiment has, to date, not achieved
a significant measure of success. The historical background of the oil drop experiment is well established in the literature
from the perspective of historians of science, but not so from the perspective of teachers and students of science. A summary
of historical details surrounding the original experiment suitable for use in revising the instructional approach is presented.
Both Millikan and his graduate student, Fletcher, are featured with the view to emphasizing details that humanize the protagonists
and that are likely to raise student interest. The issue of the necessary reliance on presuppositions in doing speculative
research is raised, both from the historical account and from the insights of university physics students who heard the historical
account and performed the experiment. Difficulties current students have in performing the experiment are discussed from the
perspective of Hodson (Stud Sci Educ 22:85–142, 1993) framework and the students’ own observations. Last, further historical
materials are outlined that may be used to encourage student insight into the fundamental nature of electricity. It is proposed
that these aspects are essential as a basis for identifying and addressing student difficulties with the Millikan oil drop
experiment.
Stephen Klassen teaches in the Department of Physics at the University of Winnipeg. His BSc and MSc were earned in Physics, and his PhD in Science Education. He has presented research at many conferences with special emphasis on including history of science in classroom activities at the college and university level. His present research interests focus on the basis of narrative and learning theories for contextual learning and for pedagogical thought experiments. 相似文献
Stephen KlassenEmail: |
Stephen Klassen teaches in the Department of Physics at the University of Winnipeg. His BSc and MSc were earned in Physics, and his PhD in Science Education. He has presented research at many conferences with special emphasis on including history of science in classroom activities at the college and university level. His present research interests focus on the basis of narrative and learning theories for contextual learning and for pedagogical thought experiments. 相似文献
78.
79.
80.
中美《桐油借款合约》是抗战初期美国对华的首次援助,增强了中国军民抗战的信心。为了偿还借款,国民政府对桐油实施统购统销,湘西的桐油业在这一时期种植面积增加,传统的运输路线发生改变,交易系统亦发生重大变化。中美签订"桐油借款"之后,传统的湘西桐油业发生了很大改变。 相似文献