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   15464篇
  免费   186篇
  国内免费   11篇
教育   10583篇
科学研究   2014篇
各国文化   120篇
体育   1055篇
综合类   5篇
文化理论   102篇
信息传播   1782篇
  2021年   160篇
  2020年   210篇
  2019年   311篇
  2018年   475篇
  2017年   420篇
  2016年   406篇
  2015年   250篇
  2014年   389篇
  2013年   2676篇
  2012年   333篇
  2011年   364篇
  2010年   320篇
  2009年   288篇
  2008年   347篇
  2007年   288篇
  2006年   280篇
  2005年   250篇
  2004年   287篇
  2003年   207篇
  2002年   214篇
  2001年   308篇
  2000年   302篇
  1999年   275篇
  1998年   160篇
  1997年   192篇
  1996年   182篇
  1995年   133篇
  1994年   147篇
  1993年   149篇
  1992年   262篇
  1991年   230篇
  1990年   216篇
  1989年   231篇
  1988年   207篇
  1987年   194篇
  1986年   194篇
  1985年   203篇
  1984年   167篇
  1983年   184篇
  1982年   153篇
  1981年   144篇
  1980年   135篇
  1979年   196篇
  1978年   153篇
  1977年   146篇
  1976年   126篇
  1975年   102篇
  1974年   122篇
  1973年   115篇
  1972年   98篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
941.
Research and development at the nanoscale requires a large degree of integration, from convergence of research disciplines in new fields of enquiry to new linkages between start-ups, regional actors and research facilities. Based on the analysis of two clusters in nanotechnologies (MESA+ (Twente) and other centres in The Netherlands and Minatec in Grenoble in France), the paper discusses the phenomenon of technological agglomeration: co-located scientific and technological fields associated to coordinated technology platforms to some extent actively shaped by institutional entrepreneurs. Such co-location and coordination are probably a pre-requisite for the emergence of strong nanoclusters.  相似文献   
942.
Aim of present study was to compare the adenosine deaminase (ADA) activity in various types of arthritis conditions with synovial effusion. No. significant difference was observed in ADA activity in serum of control and study groups but results have shown a definite pattern of ADA activity in synovial fluid in various arthritic conditions. The highest value of ADA activity was observed in synovial fluid of patients with tubercular arthritis followed by rheumatoid, septic, osteo and post traumatic arthritis. Thus measurement of ADA activity in synovial fluid can be used as a parameter of differential diagnosis of arthritis specially tubercular in initial stages.  相似文献   
943.
Oxidative stress was assesed by estimating lipid peroxidation product (LPO) in the form of thiobarbituric acid reactive substances (TBARS), enzymatic antioxidants in the form of superoxide dismutase (SOD), catalase and nonenzymatic antioxidant vitamins e.g. vitamin C, β carotene and vitamin E in either serum or plasma or erythrocytes in 190 cases of age related cataract in the age group of 50–80 years. 190 cases were grouped into three morphological types namely, 73 cases of cortical, 77 cases of posterior subcapsular and 40 cases of nuclear cataract and values of LPO and antioxidants were compared with 78 cases of age matched healthy control groups. Plasma TBARS levels were cataract cases when compared with control groups. There were no significant differences in the erythrocyte levels of catalase and plasma levels of Vit E between cataract cases and control groups. No significant changes of parameters were seen among three different morphological types of age related cataract. The present study shows that the oxidative stress may play an important role in the age related cataract.  相似文献   
944.
945.
946.
Are preservice teachers prepared to teach struggling readers?   总被引:1,自引:0,他引:1  
Reading disabilities such as dyslexia, a specific learning disability that affects an individual’s ability to process written language, are estimated to affect 15–20% of the general population. Consequently, elementary school teachers encounter students who struggle with inaccurate or slow reading, poor spelling, poor writing, and other language processing difficulties. However, recent evidence may suggest that teacher preparation programs are not providing preservice teachers with information about basic language constructs and other components related to scientifically based reading instruction. As a consequence preservice teachers have not exhibited explicit knowledge of such concepts in previous studies. Few studies have sought to assess preservice teachers’ knowledge about dyslexia in conjunction with knowledge of basic language concepts. The purpose of the present study was to examine elementary school preservice teachers’ knowledge of basic language constructs and their perceptions and knowledge about dyslexia. Findings from the present study suggest that preservice teachers, on average, are able to display implicit skills related to certain basic language constructs (i.e., syllable counting), but fail to demonstrate explicit knowledge of others (i.e., phonics principles). Also, preservice teachers seem to hold the common misconception that dyslexia is a visual perception deficit rather than a problem with phonological processing. Implications for future research as well as teacher preparation are discussed.  相似文献   
947.
Students in their first year of university face a number of transition issues that can make realising their academic potential difficult. In the sciences, first-year courses cover a large amount of material across broad subject areas, which can make them troublesome for students without background knowledge, and students need to adapt to typically large class sizes and develop active, independent learning skills. We expected a student's prior learning to be important to their academic performance in a large, first-year introductory biology subject and analysed the relationships between students' results in this course with their senior high school results in related subjects over three years from 2007 to 2009. We predicted that students with prior learning in biology would have higher results than those without it, but that chemistry might also be important, given the biochemical nature of much of the course content. Students who completed biology at the senior high school-level did perform better than those who had not, but only if they also completed chemistry. Prior learning in biology was of no benefit to students in first-year biology, except when combined with chemistry, suggesting that potential differences in biology curricula between high school and the first year at university may need to be addressed.  相似文献   
948.
949.
950.
Over the past two decades, the feminisation of primary school teaching has been identified by the media and government officials in Western countries as an important contributing factor to boys' academic problems. This panic, which has been criticised by feminists as a backlash and a form of recuperative politics, has promoted the development of research into gender and education, particularly studies related to the gendered culture of primary schools and on the masculinities of male teachers. However, male primary principals remain relatively under-researched in the literature, despite the importance of their structural position and increasing concern over the masculinisation of school leadership. This paper aims to contribute to the discussion by critically analysing the interpretive frameworks of 12 male primary school principals. The findings reveal not only the complex, contradictory and at times culturally specific gendered discourses that some male principals employ, but also their feminising and masculinising effects on the school workplace and leadership.  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