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   3581篇
  免费   177篇
  国内免费   2篇
教育   2109篇
科学研究   413篇
各国文化   9篇
体育   60篇
文化理论   58篇
信息传播   1111篇
  2023年   6篇
  2022年   5篇
  2021年   9篇
  2020年   12篇
  2019年   18篇
  2018年   81篇
  2017年   140篇
  2016年   253篇
  2015年   143篇
  2014年   61篇
  2013年   147篇
  2012年   55篇
  2011年   119篇
  2010年   41篇
  2009年   39篇
  2008年   50篇
  2007年   114篇
  2006年   75篇
  2005年   752篇
  2004年   570篇
  2003年   286篇
  2002年   84篇
  2001年   73篇
  2000年   14篇
  1999年   48篇
  1998年   85篇
  1997年   65篇
  1996年   74篇
  1995年   58篇
  1994年   80篇
  1993年   88篇
  1992年   48篇
  1991年   3篇
  1990年   29篇
  1989年   3篇
  1988年   2篇
  1986年   2篇
  1985年   4篇
  1983年   3篇
  1982年   2篇
  1979年   3篇
  1978年   1篇
  1976年   1篇
  1975年   1篇
  1973年   2篇
  1968年   1篇
  1967年   1篇
  1960年   1篇
  1918年   3篇
  1917年   2篇
排序方式: 共有3760条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
Luciferase from firefly lantern extract was immobilized on CNBr-activated Sepharose 4B. The kinetic properties of immobilized luciferase were extensively studied. TheK m′ for D-luciferin is 11.9 μmol/L, the optimum pH and temperature for Sepharose-bound enzyme were 7.8 and 25°C respectively. A luminescence fiber optic biosensor, making use of immobilized crude luciferase, was developed for assay of ATP. The peak light intensity was linear with respect to ATP concentration in range of 10−9–10−5 mol/L. A biological application was also demonstrated with the determination of serum ATP from rats bred in low versus normal oxygen environments.  相似文献   
55.
International Journal for Educational and Vocational Guidance - Combining quantitative career assessment with narrative career counselling is a career counselling challenge. The Integrative...  相似文献   
56.
57.
In 2001, for the first time in the history of the International Association for Counselling, International Conference was held in a developing Asian country–India, with the theme Families in Transition–Counselling in Transition–Meeting the Challenges Ahead. This special issue contains some of the presentations made by Indian participants during this conference which best reflect the challenges and diversities of counseling efforts with families in India. The first article was specially written for this issue in order to give an international relationship of this journal an in depth contextual understanding of Indian families in transition and the challenges they pose to the contemporary Indian counselor. Two articles are reflected to counseling families affected by socio-politial and economic changes. Five authors have written on counseling related to physical and mental disability/addiction and last two articles are reflected to authors experiences as family counselors.  相似文献   
58.
59.
Kinetic knowledge is of great importance in achieving good control of the pyrolysis and gasification process and optimising system design. An overall kinetic pyrolysis scheme is therefore addressed here. The kinetic modelling incorporates the following basic steps: the degradation of the virgin biomass materials into primary products (tar, gas and semi-char), the decomposition of primary tar into secondary products and the continuous interaction between primary gas and char. The last step is disregarded completely by models in the literature. Analysis and comparison of predicted results from different kinetic schemes and experimental data on our fixed bed pyrolyser yielded very positive evidence to support our kinetic scheme. Project (No. 2001CB409600) Supported by the National Key Basic Research Program (973) of China  相似文献   
60.
The Key Stage 3 Strategy is a complex and evolving government strategy intended to improve the education of 11‐ to 14‐year‐olds in England. This paper provides a snapshot of its development by early 2004, drawing on our evaluation of the pilot phase which began in 2000. The evolution of the Strategy, with its phased introduction of both subject and cross‐curricular strands, is described. We then examine the policy intentions and evidence base which underpin it before considering what the Strategy offers in terms of curricular and pedagogical reform. While the Strategy seeks to improve schooling for 11‐ to 14‐year‐olds, it has struggled to offer a coherent approach, though recent changes in emphasis may help. We conclude that a more radical approach to the learning needs of 11‐ to 14‐year‐olds is needed and draw evidence from international trends in middle years 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