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   11390篇
  免费   104篇
  国内免费   8篇
教育   7795篇
科学研究   1620篇
各国文化   55篇
体育   696篇
综合类   10篇
文化理论   113篇
信息传播   1213篇
  2022年   57篇
  2021年   118篇
  2020年   137篇
  2019年   187篇
  2018年   355篇
  2017年   377篇
  2016年   436篇
  2015年   273篇
  2014年   318篇
  2013年   1452篇
  2012年   347篇
  2011年   398篇
  2010年   277篇
  2009年   213篇
  2008年   289篇
  2007年   246篇
  2006年   215篇
  2005年   826篇
  2004年   626篇
  2003年   420篇
  2002年   261篇
  2001年   258篇
  2000年   230篇
  1999年   206篇
  1998年   98篇
  1997年   131篇
  1996年   111篇
  1995年   78篇
  1994年   98篇
  1993年   69篇
  1992年   165篇
  1991年   126篇
  1990年   118篇
  1989年   146篇
  1988年   128篇
  1987年   106篇
  1986年   107篇
  1985年   108篇
  1984年   79篇
  1983年   92篇
  1982年   60篇
  1981年   72篇
  1980年   61篇
  1979年   103篇
  1978年   66篇
  1977年   65篇
  1976年   57篇
  1975年   51篇
  1974年   60篇
  1973年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Cell-cell interactions play a key role in regeneration, differentiation, and basic tissue function taking place under physiological shear forces. However, current solutions to mimic such interactions by micro-patterning cells within microfluidic devices have low resolution, high fabrication complexity, and are limited to one or two cell types. Here, we present a microfluidic platform capable of laminar patterning of any biotin-labeled peptide using streptavidin-based surface chemistry. The design permits the generation of arbitrary cell patterns from heterogeneous mixtures in microfluidic devices. We demonstrate the robust co-patterning of α-CD24, α-ASGPR-1, and α-Tie2 antibodies for rapid isolation and co-patterning of mixtures of hepatocytes and endothelial cells. In addition to one-step isolation and patterning, our design permits step-wise patterning of multiple cell types and empty spaces to create complex cellular geometries in vitro. In conclusion, we developed a microfluidic device that permits the generation of perfusable tissue-like patterns in microfluidic devices by directly injecting complex cell mixtures such as differentiated stem cells or tissue digests with minimal sample preparation.  相似文献   
72.
In the article we solve path planning task for an agent being multirotor unmanned aerial vehicle (multicopter). We propose an approach of estimating path geometry constraints based on UAV flight dynamics model and control constraints. Than we introduce a new path finding method which takes into consideration those geometry constraints and study this method both theoretically and empirically.  相似文献   
73.
This study aimed to explore how children with learning disabilities (LD) perceive their quality of life (QoL) and to compare self‐reports and proxy reports regarding their QoL. Children with LD, their typically developing peers, their parents and teachers responded to the child, parent, and teacher forms of KINDLR Questionnaire for Measuring Health‐Related Quality of Life (Ravens‐Sieberer & Bullinger, 1998). Findings showed that children with LD reported significantly lower QoL scores than those reported by typically developing peers. Intraclass correlation coefficients (ICCs) and t‐test results showed that agreement between child reports and parent‐proxy reports was either low or moderate on each QoL dimension. Findings of the study may be used to raise awareness regarding the social and educational needs of children with LD in Turkey.  相似文献   
74.
This article analyzes the situation surrounding the education of the disabled in Kyrgyzstan. We provide a detailed discussion of the national legal and regulatory framework that guarantees the rights of persons with disabilities to education. We describe the actual situation in the country concerning access to education for this section of the population as well as other factors that impact it.  相似文献   
75.
76.
77.
Educational Psychology Review - In his 1973 article The Structure of ill structured problems, Herbert Simon proposed that solving ill-structured problems could be modeled within the same...  相似文献   
78.
Counselors (N = 911) reported the research skills needed for practice and subsequent research training needs. Findings indicate that counselors have a high need for research skills at work, but training needs differ significantly by counselor type. Recommendations include increasing emphasis on single‐case design, survey design, and widely available data analysis tools.  相似文献   
79.
80.
Maintaining that academic freedom is necessary if schools are to function effectively, Dr. Dahl presents lucid arguments to support his position.  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