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   290篇
  免费   4篇
教育   197篇
科学研究   3篇
各国文化   11篇
体育   22篇
信息传播   61篇
  2022年   1篇
  2020年   6篇
  2019年   6篇
  2018年   13篇
  2017年   18篇
  2016年   7篇
  2015年   7篇
  2014年   12篇
  2013年   71篇
  2012年   7篇
  2011年   9篇
  2010年   9篇
  2009年   4篇
  2008年   9篇
  2007年   11篇
  2006年   13篇
  2005年   12篇
  2004年   11篇
  2003年   9篇
  2002年   6篇
  2001年   5篇
  2000年   10篇
  1999年   7篇
  1998年   2篇
  1997年   2篇
  1996年   3篇
  1995年   3篇
  1993年   3篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1987年   2篇
  1986年   2篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1978年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有294条查询结果,搜索用时 15 毫秒
71.
72.
73.
This column features an overview of the Division of Specialized Information Services, National Library of Medicine Household Products Database. Basic searching techniques are presented, as well as a brief overview of the data contained in this file. The Household Products Database contains information on chemical ingredients in various products used in U.S. homes.  相似文献   
74.
75.
This article describes the process of finding the right grant to meet the needs of a processing project, the application and peer review process, and the experience of administering the grant received from the National Historical Publications and Records Commission (NHPRC). The project is the processing of the YWCA of Brooklyn Collection, housed at Brooklyn College. The records have significant research potential in a variety of fields including women’s studies and sociology. While generally smooth, the administration of the grant has required the replacement of a departing Project Archivist, and the use of interns for some conservation work.  相似文献   
76.
77.
This article tells the story of an attempt to bring about major educational reform of the curriculum and educational values in Kazakhstan, using action research as part of that process. The article begins with a brief and selective review of the literature on aspects of emotion and moves to an account of the context and history of the reforms, before focusing on the ‘self experience’ of the participants and the authors. Emotion, its centrality and the interrelationship of three areas – the nature of teaching and teacher learning, the process of change and the experience of research – are explored in relation to reform and action research. The paper concludes with a reflection on the implications for the use of action research as a strategy for reform.  相似文献   
78.
The two authors were paired as part of a formal mentoring program for orientation and to prepare for eventual promotion and tenure. One author has over twenty-five years’ experience on campus, and the other author has completed one year in her current position. During that first year, various themes emerged to remind both librarians that the more things change, the more they remain the same. As the mentoring experience evolved, it became difficult to distinguish the mentor from the mentee because both librarians understood that discussing common issues was mutually beneficial.  相似文献   
79.
The objective of this study was to test the association of the rs1049305 (G > C) variant within the 3?-untranslated region of the aquaporin 1 gene, AQP1, with changes in body weight, post-race serum sodium concentration and performance in Ironman triathletes. Five hundred and four male Ironman triathletes were genotyped for the rs1049305 variant within the AQP1 gene. Change in pre- and post-race body weight was calculated for 470 triathletes and used as a proxy for changes in body fluid during the race, as well as to divide triathletes into biologically relevant weight-loss groups (0–3%, 3–5% and >5%). There were no rs1049305 genotype effects on post-race serum sodium concentrations (P = 0.647), pre-race weight (P = 0.610) nor relative weight change during the Ironman Triathlons (P = 0.705). In addition, there were no significant differences in genotype (= 0.640) nor allele (= 0.643) distributions between the weight loss groups. However, triathletes who carry a C-allele were found to complete the 42.2-km run stage faster (mean 286, = 49 min) than triathletes with a GG genotype (mean 296, = 47 min; P = 0.032). The AQP1 rs1049305 variant is associated with running performance, but not relative body weight change, during the 2000, 2001 and 2006 South African Ironman Triathlons.  相似文献   
80.
A new strategy for magnetically manipulating and isolating adherent cells with extremely high post-collection purity and viability is reported. Micromolded magnetic elements (termed microrafts) were fabricated in an array format and used as culture surfaces and carriers for living, adherent cells. A poly(styrene-co-acrylic acid) polymer containing well dispersed magnetic nanoparticles was developed for creating the microstructures by molding. Nanoparticles of γFe(2)O(3) at concentrations up to 1% wt.∕wt. could be used to fabricate microrafts that were optically transparent, highly magnetic, biocompatible, and minimally fluorescent. To prevent cellular uptake of nanoparticles from the magnetic polymer, a poly(styrene-co-acrylic acid) layer lacking γFe(2)O(3) nanoparticles was placed over the initial magnetic microraft layer to prevent cellular uptake of the γFe(2)O(3) during culture. The microraft surface geometry and physical properties were altered by varying the polymer concentration or layering different polymers during fabrication. Cells plated on the magnetic microrafts were visualized using standard imaging techniques including brightfield, epifluorescence, and confocal microscopy. Magnetic microrafts possessing cells of interest were dislodged from the array and efficiently collected with an external magnet. To demonstrate the feasibility of cell isolation using the magnetic microrafts, a mixed population of wild-type cells and cells stably transfected with a fluorescent protein was plated onto an array. Microrafts possessing single, fluorescent cells were released from the array and magnetically collected. A post-sorting single-cell cloning rate of 92% and a purity of 100% were attained.  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