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   277篇
  免费   3篇
  国内免费   1篇
教育   156篇
科学研究   42篇
各国文化   2篇
体育   32篇
文化理论   28篇
信息传播   21篇
  2023年   1篇
  2022年   4篇
  2021年   4篇
  2020年   13篇
  2019年   26篇
  2018年   12篇
  2017年   22篇
  2016年   24篇
  2015年   5篇
  2014年   20篇
  2013年   46篇
  2012年   19篇
  2011年   11篇
  2010年   12篇
  2009年   4篇
  2008年   5篇
  2007年   7篇
  2006年   6篇
  2005年   5篇
  2004年   1篇
  2003年   2篇
  2002年   6篇
  2001年   1篇
  2000年   4篇
  1998年   1篇
  1997年   1篇
  1996年   3篇
  1995年   2篇
  1994年   4篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1985年   2篇
  1983年   1篇
  1981年   1篇
  1972年   1篇
排序方式: 共有281条查询结果,搜索用时 281 毫秒
91.
Adolescents who work while attending school are reported to sleep less than those who do not. This study aimed to identify factors associated with short sleep duration in students who work during the school year. A cross‐sectional survey aiming to describe working conditions and occupational safety and health was completed by representative samples of Quebec high school students aged 12–19 years from three administrative regions (n = 3,871). A multiple stepwise regression analysis was performed with sleep duration as the dependent variable, and sociodemographic, school, occupational, and health factors as potential explanatory variables. Significant factors associated with shorter sleep duration were later bedtimes (p < .001), shorter weekend oversleep (p < .001), higher physical work factors related to handling efforts (p < .001), and female gender (p < .01). Addressing work conditions of student workers may help prevent sleep deprivation. Special efforts should also target girls combining work and study.  相似文献   
92.
This study examines the effect of antitrust regulation of patent consolidation on the development of follow-on innovations. Our reconciliation of the various strains of literature hypothesizes that in sectors where cumulative innovation is crucial to firms’ market operations, a firm that consolidates patents for substituting technologies for its already-possessed technologies discourages market competitions and follow-on innovation by competitors. In this case, antitrust regulation of patent consolidation is anticipated to positively affect competitors’ follow-on innovation. We empirically test this hypothesis with the case of the US Department of Justice's regulation of Novell's software patent transfers to four large proprietary software companies (i.e., Microsoft, Oracle, EMC, and Apple) in 2011. Our analyses using US patent, trademark, and copyright data have found evidence corroborating our hypothesis. Our research provides policy and scholarly implications regarding how antitrust law can be a complementary institution to the patent law for promoting innovation.  相似文献   
93.
In this paper, we explore the work life of a scholar new to academia in her methods of leading informally. We discuss five vignettes that offer moments of learning and reflection, including reducing performance anxiety, privileging financial accountability, the rise of the virtual world, the impact of silence, and the potential for confrontation to strengthen working relationships. We offer suggestions as to how contemporary leaders may adapt to the freedom that artful action offers.  相似文献   
94.
本文从降低供应风险的角度,对2020年前我国原油进口结构的优化路径进行了定量分析。并且为应对伊朗原油出口的减少提出了数量化的政策建议。研究结论显示,由于我国对世界原油的需求将会持续旺盛,在未来几年内,我国需要大量增加从俄罗斯、科威特、阿联酋、卡塔尔、墨西哥及阿尔及利亚等传统产油国的进口,同时减少对沙特阿拉伯、安哥拉、苏丹和伊朗的原油依赖。从未来原油进口的地区分布上看,中东地区依然是我国原油进口的主要来源地,同时也是供应风险最大的地区。为应对伊朗石油禁运,我国应该增加从加拿大、墨西哥、尼日利亚和卡塔尔等国的原油进口来弥补供应缺口,并满足国内快速增长的原油消费需求。  相似文献   
95.
We present a 91 MHz surface acoustic wave resonator with integrated microfluidics that includes a flow focus, an expansion region, and a binning region in order to manipulate particle trajectories. We demonstrate the ability to change the position of the acoustic nodes by varying the electronic phase of one of the transducers relative to the other in a pseudo-static manner. The measurements were performed at room temperature with 3 μm diameter latex beads dispersed in a water-based solution. We demonstrate the dependence of nodal position on pseudo-static phase and show simultaneous control of 9 bead streams with spatial control of −0.058 μm/deg ± 0.001 μm/deg. As a consequence of changing the position of bead streams perpendicular to their flow direction, we also show that the integrated acoustic-microfluidic device can be used to change the trajectory of a bead stream towards a selected bin with an angular control of 0.008 deg/deg ± 0.000(2) deg/deg.  相似文献   
96.
Concept maps are proposed as an alternative tool for evaluation in higher education and examples of concept maps, drawn by college students performing evaluation tasks, are presented in the areas of physics and literature.  相似文献   
97.
98.
99.
The research undertaken for this article aims to analyse the correspondence between perceived employability and the actual national employment rate among Italian students and graduates undertaking different courses in a large Italian university. Data were collected through a cross-sectional survey of 2087 students in 19 faculties, and compared with the national indicators of employment rate for each faculty. Using faculty as unit of analysis, the results indicated a significant correlation between participants’ perceived employability and national employment rate. This trend was similar for both genders. However, the results showed a difference between bachelor’s and master’s degrees: the correlation between perceived and actual employability was not significant among bachelor’s participants while it remained significant among master’s participants. The results suggest that graduates are only partially aware of their possibility to enter the labour market and this, in turn, highlights that universities have only partially met the goal to increase awareness about the chances of finding a job among students and graduates.  相似文献   
100.
Evolution is considered an essential topic that brings to school a broader perspective of natural phenomena and of the nature of science. Most if not all research has shown that the result of the teaching of evolutionary theories is not positive in different parts of the world. Some have attributed the poor understanding shown by students to teaching style or to students' cognitive abilities. This article reports results of interviews and tests carried out with students after they had been taught the topic of evolution. By adopting a sociocultural perspective, before terming students' views “misconceptions,” attention was given to several different ways Charles Darwin's theories have been re-interpreted by well-known scholars and offered to the public. I have analyzed the approaches taken by Emanuel Radl (1873-1942), John C. Greene, Robert Maxwell Young, and Ernst Mayr to assess the diverse ways Darwinism has been conceived. Attention was also given to the presentation of this controversial knowledge to the public in two major popular books written by respected scientists, Huxley and Kettlewell's Darwin and His World (1975) and Richard Dawkins' more recent The Blind Watchmaker (1989). These analyses revealed remarkable differences between what was written in Downe (Kent) a hundred years ago and what was heard at Sao Paulo (Brazil) nowadays. Students show very poor understanding of evolutionary theories. Their conceptions reveal evolution has been primarily related to the human species. Its meaning is understood as similar to progress, growth, multiplication, and improvement. Biological and cultural evolution are not clearly distinguished. Competition is misunderstood as pure violence, sometimes inevitable, and adaptation is considered an individual process that occurs during the organism's life span. Educational change may not depend just on teaching style and students' cognitive abilities. Modification of factual knowledge and epistemological gaps may be the result of a process of social reconceptualization of knowledge offered to students.  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