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   15094篇
  免费   220篇
  国内免费   12篇
教育   10322篇
科学研究   1336篇
各国文化   159篇
体育   1581篇
综合类   22篇
文化理论   116篇
信息传播   1790篇
  2021年   113篇
  2020年   227篇
  2019年   313篇
  2018年   373篇
  2017年   445篇
  2016年   389篇
  2015年   254篇
  2014年   335篇
  2013年   2753篇
  2012年   292篇
  2011年   342篇
  2010年   266篇
  2009年   307篇
  2008年   281篇
  2007年   280篇
  2006年   255篇
  2005年   232篇
  2004年   479篇
  2003年   373篇
  2002年   401篇
  2001年   251篇
  2000年   268篇
  1999年   216篇
  1998年   101篇
  1997年   133篇
  1996年   155篇
  1995年   144篇
  1994年   135篇
  1993年   131篇
  1992年   181篇
  1991年   183篇
  1990年   170篇
  1989年   217篇
  1988年   181篇
  1987年   212篇
  1986年   182篇
  1985年   236篇
  1984年   194篇
  1983年   178篇
  1982年   155篇
  1981年   134篇
  1980年   111篇
  1979年   177篇
  1978年   137篇
  1977年   123篇
  1976年   147篇
  1975年   106篇
  1974年   118篇
  1973年   96篇
  1971年   107篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
963.
964.
965.
Maximal voluntary static muscle force production was assessed both in strength trials and during 2-min contractions by three muscle groups (right-hand finger flexors [RHF], right-leg extensors [RLE], and both leg extensors [BLE]) in young males (n = 13) and females (n = 14). There was a significant difference (p less than .01) between males and females for RHF strength and BLE strength but no significant difference between sexes for RLE strength. During the 2-min task, impulse (force x time) declined significantly (p less than .001) and there was a significant difference (p less than .001) between muscle groups, but there was no difference between sexes. There was a significant (p less than .05) sex x time interaction for the impulse values indicating that the fatigability was greater in males than females.  相似文献   
966.
Abstract

The aim of this study was to develop a performance test set-up for America's Cup grinders. The test set-up had to mimic the on-boat grinding activity and be capable of collecting data for analysis and evaluation of grinding performance. This study included a literature-based analysis of grinding demands and a test protocol developed to accommodate the necessary physiological loads. This study resulted in a test protocol consisting of 10 intervals of 20 revolutions each interspersed with active resting periods of 50 s. The 20 revolutions are a combination of both forward and backward grinding and an exponentially rising resistance. A custom-made grinding ergometer was developed with computer-controlled resistance and capable of collecting data during the test. The data collected can be used to find measures of grinding performance such as peak power, time to complete and the decline in repeated grinding performance.  相似文献   
967.
968.
In this methodological discussion, the authors detail and reflect on the processes of using photo-elicitation interviewing as a way to align with positive qualitative methodologies, to gain access to participant beliefs and values, and to highlight participant voices through their choices of words and visuals. A review of the literature and an overview of the educational research experiences leading to the discussion are included. Next, the discoveries regarding what is methodologically new and/or valuable concerning this visual method is presented. In the final section, the authors reflexively contemplate aspects of visual methodological processes in an effort to address methodological crossroads of potential and tension including: (1) the potential of decontextualized photos, (2) photos as metaphors of meaning, (3) photos as representations of inherent meaning, (4) participant empowerment, and (5) graphic representation or graphic portraits.  相似文献   
969.
Published evaluations of career preparation of alumni from long-standing postdoctoral fellowship programs in the biomedical sciences are limited and often focus on quantitative analysis of data from extant publicly available sources. Qualitative methods provide the opportunity to gather robust information about specific program elements from structured postdoctoral training programs and the influence of this training on subsequent career paths of alumni. In-depth interviews with a subset of the National Cancer Institute’s Cancer Prevention Fellowship Program (CPFP) alumni (n = 27), representing more than 25 years of the program’s history and multiple career sectors, were conducted to assess alumni reflections on the training environment and career preparation during their time in the CPFP. NVivo software was used to analyze data and identify major themes. Four main themes emerged from these interviews, including: the value of structured training curriculum, mentorship, transdisciplinary environment, and professional identity. Even when reflecting on training that occurred one to two decades earlier, alumni were able to highlight specific components of a structured postdoctoral training program as influencing their research and career trajectories. These results may have relevance for those interested in assessing how postdoctoral training can influence fellows throughout their careers and understanding salient features of structured programs.  相似文献   
970.
The contributions of volunteers in special libraries have not been well-documented or researched. However, anecdotal evidence shows that volunteers have played a key role in the formation of many special libraries and continue to lend their skills and knowledge to these libraries. This column explores examples from the literature and gives a brief case study on the various ways philatelic libraries use volunteers. The scope of the column includes traditional unpaid volunteers, remote volunteers, crowdsourcing, internships, job training programs, and other voluntary or nontraditional work. Volunteer labor is far from free in terms of cost to the organization, but can provide benefits beyond simply unpaid labor including subject expertise, special skills, and community building. Special libraries looking to begin or expand volunteer programs are advised to study the lessons learned from other types of libraries and organizations with successful volunteer programs. Successfully managing volunteers requires careful planning and coordination just as managing paid staff does.  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