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   1489篇
  免费   36篇
教育   967篇
科学研究   62篇
各国文化   33篇
体育   242篇
文化理论   17篇
信息传播   204篇
  2023年   11篇
  2022年   8篇
  2021年   21篇
  2020年   45篇
  2019年   58篇
  2018年   119篇
  2017年   118篇
  2016年   101篇
  2015年   63篇
  2014年   57篇
  2013年   387篇
  2012年   63篇
  2011年   51篇
  2010年   32篇
  2009年   44篇
  2008年   36篇
  2007年   39篇
  2006年   27篇
  2005年   21篇
  2004年   22篇
  2003年   19篇
  2002年   22篇
  2001年   9篇
  2000年   4篇
  1999年   7篇
  1998年   12篇
  1997年   12篇
  1996年   10篇
  1995年   9篇
  1994年   3篇
  1993年   7篇
  1992年   5篇
  1991年   6篇
  1990年   3篇
  1989年   4篇
  1988年   5篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1984年   3篇
  1982年   2篇
  1980年   3篇
  1979年   4篇
  1978年   5篇
  1977年   4篇
  1976年   8篇
  1975年   6篇
  1974年   6篇
  1973年   3篇
  1966年   2篇
排序方式: 共有1525条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
Women in American science   总被引:3,自引:0,他引:3  
  相似文献   
105.
Objectives: This article examines a strategic approach to developing e‐learning capability to enhance learning opportunities for the workforce of a healthcare organization. Emphasis is given to the procurement of a bespoke Managed Learning Environment (MLE). Strategic organizational issues impacting on future e‐learning developments are considered. Methods: The 2‐year implementation plan was evaluated through a two phase external research project. The first phase focused on the effectiveness of a training programme designed to build capacity for e‐learning within the Northern area and also included a virtual learning environment usability study which informed the MLE specification. The second phase evaluation is ongoing during 2005 and interim findings are presented. Results: The MLE has been piloted and on‐line learning packages have been acquired. There has been a phased take‐up of e‐learning opportunities and e‐tutor training. Some virtual Communities of Practice have been established. Key organizational issues have been identified and ongoing findings are informing strategic planning. Conclusions: The healthcare MLE is offering enhanced learning opportunities and assisting area healthcare providers in training their dispersed workforces. Blended learning strategies are most successful. The need for protected time for e‐learning is a key issue, financial savings are available. Progress has been slowed by identified organizational constraints—the MLE's benefits are widely recognized.  相似文献   
106.
A multitrait-multimethod (MTMM) matrix was used to evaluate validity evidence for a digital image manipulation (DIM) body image measurement technique in young women. One hundred one young women completed the DIM procedure and the Thompson and Gray (1995) Contour Drawing Rating Scale to measure self-ideal discrepancy and size perception accuracy components of body image. Seven-day test-retest reliability was acceptable (R = .81-.95). Convergent validity for self-ideal discrepancy was higher (r = .74) than the corresponding heterotrait, monomethod coefficients (r = .46, r = .23) and heterotrait-heteromethod coefficients (r = .18, r = .12). However, the convergent validity coefficient for size perception accuracy was r = .12. The pattern of correlations in the MTMM matrix met the criteria of Campbell and Fiske (1959) for validity of these procedures to measure self-ideal discrepancy but not size perception accuracy. The DIM procedure addresses some of the criticisms associated with figure-rating scales, such as unrepresentativeness of the figures, scale coarseness, and restriction of range in responses. DIM, therefore, represents a realistic, valid alternative to figure-rating scales for measuring self-ideal discrepancy.  相似文献   
107.
108.
PurposeThe aim of this study was to evaluate the efficacy of a 17-week, 3-component lifestyle intervention for enhancing health behaviors during the coronavirus disease 2019 (COVID-19) pandemic.MethodsA parallel-group (intervention and control) study was conducted amongst 79 airline pilots over a 17-week period during the COVID-19 pandemic. The intervention group (n = 38) received a personalized sleep, dietary, and physical activity (PA) program. The control group (n = 41) received no intervention. Outcome measures for sleep, fruit and vegetable intake, PA, and subjective health were measured though an online survey before and after the 17-week period. The changes in outcome measures were used to determine the efficacy of the intervention.ResultsSignificant main effects for time × group were found for International Physical Activity Questionnaire-walk (p = 0.02) and for all other outcome measures (p < 0.01). The intervention group significantly improved in sleep duration (p < 0.01; d = 1.35), Pittsburgh Sleep Quality Index score (p < 0.01; d = 1.14), moderate-to-vigorous PA (p < 0.01; d = 1.44), fruit and vegetable intake (p < 0.01; d = 2.09), Short Form 12v2 physical score (p < 0.01; d = 1.52), and Short Form 12v2 mental score (p < 0.01; d = 2.09). The control group showed significant negative change for sleep duration, Pittsburgh Sleep Quality Index score, and Short Form 12v2 mental score (p < 0.01).ConclusionResults provide preliminary evidence that a 3-component healthy sleep, eating, and PA intervention elicit improvements in health behaviors and perceived subjective health in pilots and may improve quality of life during an unprecedented global pandemic.  相似文献   
109.
110.
The present work describes the operation and simulation of a microfluidic laminar-flow mixer. Diffusive mixing takes place between a core solution containing lipids in ethanol and a sheath solution containing aqueous buffer, leading to self assembly of liposomes. Present device architecture hydrodynamically focuses the lipid solution into a cylindrical core positioned at the center of a microfluidic channel of 125 × 125-μm2 cross-section. Use of the device produces liposomes in the size range of 100–300 nm, with larger liposomes forming at greater ionic strength in the sheath solution and at lower lipid concentration in the core solution. Finite element simulations compute the concentration distributions of solutes at axial distances of greater than 100 channel widths. These simulations reduce computation time and enable computation at long axial distances by utilizing long hexahedral elements in the axial flow region and fine tetrahedral elements in the hydrodynamic focusing region. Present meshing technique is generally useful for simulation of long microfluidic channels and is fully implementable using comsol Multiphysics. Confocal microscopy provides experimental validation of the simulations using fluorescent solutions containing fluorescein or enhanced green fluorescent protein.  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