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   1027篇
  免费   171篇
教育   222篇
科学研究   45篇
体育   8篇
综合类   1篇
文化理论   7篇
信息传播   915篇
  2023年   3篇
  2022年   11篇
  2021年   12篇
  2020年   6篇
  2019年   13篇
  2018年   25篇
  2017年   15篇
  2016年   72篇
  2015年   76篇
  2014年   27篇
  2013年   47篇
  2012年   12篇
  2011年   22篇
  2010年   9篇
  2009年   10篇
  2008年   7篇
  2007年   80篇
  2006年   34篇
  2005年   10篇
  2004年   61篇
  2003年   5篇
  2002年   1篇
  2001年   69篇
  1999年   42篇
  1998年   83篇
  1997年   66篇
  1996年   71篇
  1995年   52篇
  1994年   79篇
  1993年   85篇
  1992年   46篇
  1991年   2篇
  1990年   30篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   2篇
  1984年   1篇
  1981年   1篇
  1977年   1篇
  1976年   2篇
  1971年   1篇
  1961年   1篇
排序方式: 共有1198条查询结果,搜索用时 31 毫秒
21.
基于互联网社区的消费者需求信息采集策略   总被引:1,自引:0,他引:1  
徐颖  李倩 《图书情报工作》2011,55(24):121-125
从互联网社区参与者角色--社区建设者、主题发布者、话题讨论者出发,提出企业在互联网社区上采集消费者需求信息的基本方针,分析在互联网社区上消费者需求信息表现形式的转化过程,构建在互联网社区上采集消费者需求信息的具体路线,以此为企业制定在互联网社区上采集消费者需求信息策略提供借鉴。  相似文献   
22.
本文在选取我国图书馆学情报学领域24种典型期刊的基础上,利用期刊同被引分析方法对从CNKI中检索出的1999—2009年的期刊同被引数据进行了分析,包括聚类分析、多维尺度分析和因子分析,得出了期刊的关系与结构及其在图书馆学情报学领域中的地位。  相似文献   
23.
Found in all eukaryotic cells, linker histones H1 are known to bind to and rearrange nucleosomal linker DNA. In vitro, the fundamental nature of H1∕DNA interactions has attracted wide interest among research communities-from biologists to physicists. Hence, H1∕DNA binding processes and structural and dynamical information about these self-assemblies are of broad importance. Targeting a quantitative understanding of H1 induced DNA compaction mechanisms, our strategy is based on using small-angle x-ray microdiffraction in combination with microfluidics. The usage of microfluidic hydrodynamic focusing devices facilitates a microscale control of these self-assembly processes, which cannot be achieved using conventional bulk setups. In addition, the method enables time-resolved access to structure formation in situ, in particular, to transient intermediate states. The observed time dependent structure evolution shows that the H1∕DNA interaction can be described as a two-step process: an initial unspecific binding of H1 to DNA is followed by a rearrangement of molecules within the formed assemblies. The second step is most likely induced by interactions between the DNA and the H1's charged side chains. This leads to an increase in lattice spacing within the DNA∕protein assembly and induces a decrease in the correlation length of the mesophases, probably due to a local bending of the DNA.  相似文献   
24.
Education and Information Technologies - Computational thinking in the educational environment has awaken a rising interest, having been included as part of the curricula from the very beginnings...  相似文献   
25.
Journal of Mathematics Teacher Education - To better understand the critical early years of teaching and teacher identity development, this study explored the mathematics teacher identity of two...  相似文献   
26.
27.
Based on findings from a semester-long study, this article examines the development of Samoan prospective teachers’ mathematical understandings and mathematics attitudes when investigating authentic contexts and applying working mathematically processes, mental computations and problem-solving strategies to find solutions of problems. The prospective teachers had enrolled for the second time (having failed their first attempt), in the first-year mathematics methods course of a 2-year Diploma of Education (Primary) programme. The group also included those enrolled in the Diploma of Education (Early Childhood and Special Needs) programmes, who recognizing their own limited understanding of mathematics would ordinarily shy away from opportunities for improvement. Given the negative mathematical and learning experiences, this group was ideal to engage in innovative and creative approaches that would make mathematics learning more meaningful and contextual in a Samoan environment. Only data from the attitudinal questionnaires and interviews are presented in this article. Main findings have implications for teaching and learning mathematics.  相似文献   
28.
This study examined the influence of the regression model and initial intensity of an incremental test on the relationship between the lactate threshold estimated by the maximal-deviation method and the endurance performance. Sixteen non-competitive, recreational female runners performed a discontinuous incremental treadmill test. The initial speed was set at 7 km · h?1, and increased every 3 min by 1 km · h?1 with a 30-s rest between the stages used for earlobe capillary blood sample collection. Lactate-speed data were fitted by an exponential-plus-constant and a third-order polynomial equation. The lactate threshold was determined for both regression equations, using all the coordinates, excluding the first and excluding the first and second initial points. Mean speed of a 10-km road race was the performance index (3.04 ± 0.22 m · s?1). The exponentially-derived lactate threshold had a higher correlation (0.98 ≤ r ≤ 0.99) and smaller standard error of estimate (SEE) (0.04 ≤ SEE ≤ 0.05 m · s?1) with performance than the polynomially-derived equivalent (0.83 ≤ r ≤ 0.89; 0.10 ≤ SEE ≤ 0.13 m · s?1). The exponential lactate threshold was greater than the polynomial equivalent (P < 0.05). The results suggest that the exponential lactate threshold is a valid performance index that is independent of the initial intensity of the incremental test and better than the polynomial equivalent.  相似文献   
29.
The methodology of protecting the European stained glass windows against environmental risk (e.g. meteorological factors, air pollution, microorganisms) by means of an external glazing is not new. In spite of many scientific studies carried out in the last 20 years, some questions were still up for discussion. The European VIDRIO (2002–2005) project gave an answer to these questions. The research carried out by the different project partners established a new multidisciplinary approach aimed at evaluating the efficiency of the protective glazing systems and their effects on stained glass windows conservation, and finally at assessing the most appropriate strategy to preserve stained glass windows. Scientific results showed that the so-called isothermal glazing (i.e. ventilation by the air coming from the inside of the building) protected efficiently the ancient stained glass window from environmental attack (i.e. rain, pollutants, condensation, thermal shocks) with very limited secondary effects. The scientific research highlighted that its efficiency was strongly related to the technical design of the protective system. In particular, the ventilation and the size of the interspace had to be carefully considered. The research developed within the VIDRIO project was turned into general recommendations to the owners and practitioners on the best practice for the stained glass windows future conservation.  相似文献   
30.
A mentor’s aid in developing the competences of teacher trainees   总被引:1,自引:0,他引:1  
The induction period is a very important time in the career of a teacher and has a long‐term influence on the teacher’s professional development, efficacy, job satisfaction and the length of his/her career. One of the key roles in this period is played by the trainee’s mentor. This paper presents the results of the extensive project ‘Partnership of Faculties and Schools’, carried out at the Pedagogical Faculty, University of Ljubljana, with the financial support of the European Social Fund and the Slovenian Ministry of Education, Science and Sport. We studied an induction project involving 361 teacher trainees and 331 mentors. The study reveals the trainees’ expectations towards their mentors and the mentors’ and trainees’ evaluations of how the mentor aids a teacher trainee in developing their competences.  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