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   492篇
  免费   13篇
教育   337篇
科学研究   22篇
各国文化   8篇
体育   53篇
信息传播   85篇
  2021年   3篇
  2020年   8篇
  2019年   16篇
  2018年   28篇
  2017年   28篇
  2016年   21篇
  2015年   10篇
  2014年   15篇
  2013年   110篇
  2012年   11篇
  2011年   15篇
  2010年   14篇
  2009年   6篇
  2008年   7篇
  2007年   13篇
  2006年   4篇
  2005年   7篇
  2004年   10篇
  2003年   8篇
  2002年   7篇
  2001年   2篇
  2000年   7篇
  1999年   7篇
  1998年   5篇
  1997年   9篇
  1996年   6篇
  1995年   4篇
  1994年   6篇
  1993年   5篇
  1992年   14篇
  1991年   4篇
  1990年   11篇
  1989年   7篇
  1988年   3篇
  1987年   6篇
  1986年   4篇
  1985年   2篇
  1984年   6篇
  1983年   4篇
  1982年   6篇
  1981年   4篇
  1980年   4篇
  1979年   4篇
  1978年   4篇
  1977年   3篇
  1976年   3篇
  1973年   3篇
  1971年   3篇
  1968年   2篇
  1927年   2篇
排序方式: 共有505条查询结果,搜索用时 31 毫秒
21.
[1](路透社)意大利瓦尔达罗电——意大利将不会分离它石器时代的“情侣”。[2]科学家说他们决定把这对相拥5000年之久的情侣遗体整体移动并保存,作为献给全国的情人节礼物,在他们永远拥抱的姿势中,他们的胳膊仍然相互缠绕在一起。  相似文献   
22.
23.
It is known that an increased level of red blood cell 2,3-diphosphoglycerate (DPG) shifts the oxyhemoglobin dissociation curve to the right, thus allowing a greater unloading of oxygen at the tissue level. It has been hypothesized that phosphate might help increase VO2max by increasing 2,3-DPG level. Eight trained cyclists underwent three cycle ergometer tests (control, placebo, and experimental) to determine whether phosphate ingestion had any positive effect on VO2max, time to exhaustion, serum 2,3-DPG, and serum phosphate levels. We found no change between the control, placebo, or experimental conditions in pretest serum phosphate levels, but we did find increases in 2,3-DPG levels in the phosphate condition (p less than .05), which suggests that even a small amount of phosphate could increase levels of 2,3-DPG. We also found significant differences in VO2max between the control (p less than .05) and placebo (p less than .02) conditions and also in time to exhaustion between the three conditions (p less than .05). We suggest that phosphate may have an ergogenic effect, but clearly more work needs to be undertaken to ascertain the amount of phosphate required and the magnitude of the effect.  相似文献   
24.
25.
26.
In this quasi-experimental mixed methods study, we examined the effectiveness of a faculty-to-faculty mentoring program to increase student success rates in online courses at an American university. Over one semester, 24 faculty mentees worked with 6 faculty mentors on improving course organization and implementing student engagement techniques. Using methodological triangulation, we found positive results for two of our effectiveness measures (i.e., mentor and mentee feedback and mentors’ ratings of mentees’ courses). However, in terms of our third measure (i.e., student learning data), although institutional data showed that there was a 4.1% aggregate increase in online student success after the intervention, the intervention group made no significantly greater gains than two control groups. Our findings highlight some benefits and shortcomings of these types of university initiatives and also emphasize the importance of using triangulation to integrate participant feedback with formal measures of student success.  相似文献   
27.
This paper identifies salient practices of faculty mentors of undergraduate research (UR) as indicated in the extensive literature of the past two decades on UR. The well-established benefits for students involved in UR are dependent, first and foremost, on high-quality mentoring. Mentorship is a defining feature of UR. As more and different types of colleges and universities strive to meet student demand for authentic scholarly experiences, it is imperative to identify what effective UR mentors do in order to ensure student engagement, quality enhancement, retention, and degree-completion. We offer an original analysis of the literature on UR mentoring in which we identify 10 significant “lessons learned,” or evidence-based practices of effective UR mentors that apply broadly across disciplines, students, institutions, and mentoring approaches.  相似文献   
28.
The responsiveness to change of the Actical and ActiGraph accelerometers was assessed in children and adolescents. Participants (N = 208) aged 6 to 16 years completed two simulated free-living protocols, one with primarily light-to-moderate physical activity (PA) and one with mostly moderate-to-vigorous PA. Time in sedentary, light, moderate, and vigorous PA was estimated using 8 previously developed cut-points (4 for Actical and 4 for ActiGraph) and 5-sec, 15-sec, and 30-sec epochs. Accelerometer responsiveness for detecting differences in PA between protocols was assessed using standardized response means (SRMs). SRM values ≥.8 represented high responsiveness to change. Both accelerometers showed high responsiveness for all PA intensities (SRMs = 1.2–4.7 for Actical and 1.1–3.3 for ActiGraph). All cut-points and epoch lengths yielded high responsiveness, and choice of cut-points and epoch length had little effect on responsiveness. Thus, both the Actical and ActiGraph can detect change in PA in a simulated free-living setting, irrespective of cut-point selection or epoch length.  相似文献   
29.
Objective. Parenting behavior is presumed to be related to the thoughts about child behavior that parents report in a controlled and explicit manner and to more implicit parent cognitions that occur outside of conscious awareness and are less accessible to verbal report. Design. We examined mothers’ attitudes toward their children as correlates of self-reported parenting behavior. We used a combination of a self-report questionnaire and a reaction-time method (the Implicit Association Test) to assess explicit and implicit attitudes, respectively. We also assessed mothers’ implicit and explicit attributions for child misbehavior in relation to parenting, using a questionnaire measure of attributions completed under high-cognitive load (implicit attributions) or under low-cognitive load (explicit attributions). Mothers of 124, 6- to 10-year-olds (52% male) participated. Results. Attitudes assessed by self-report questionnaire and the Implicit Association Test were uniquely associated with negative parenting. The cognitive load manipulation moderated associations between attributions and parenting, such that child-blaming attributions were inversely associated with positive parenting only under conditions of high-cognitive load. Conclusions. Compared to traditional self-report questionnaires, methods such as the Implicit Association Test or cognitive load manipulations may more effectively assess implicit parent cognitions.  相似文献   
30.
This article reports on a two-year ethnographic study of learners participating in multi-site, graduate-level education classes. Classes sometimes met face-to-face in the same physical location; at other times part of the class met physically elsewhere. Yet all were linked through the virtual space. Ethnographic analysis of four data types explored how the instructor and students were able to interact through videoconferencing technologies. Most of the interaction occurred between the local and distance learners by way of cultural guides, local students assigned to host a distance learner through Google Video chat. The distance learners were able to receive real-time attention from the instructor and were able to share differing perspectives that contributed to increased satisfaction in the course. These interactions allowed for a dynamic collaborative effort among a diverse set of actors in the field of education.  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