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   11617篇
  免费   2篇
教育   8929篇
科学研究   1284篇
体育   338篇
文化理论   384篇
信息传播   684篇
  2022年   2篇
  2021年   8篇
  2020年   3篇
  2019年   4篇
  2018年   2174篇
  2017年   2077篇
  2016年   1566篇
  2015年   112篇
  2014年   119篇
  2013年   93篇
  2012年   226篇
  2011年   688篇
  2010年   832篇
  2009年   431篇
  2008年   641篇
  2007年   1149篇
  2006年   70篇
  2005年   394篇
  2004年   445篇
  2003年   359篇
  2002年   130篇
  2001年   8篇
  2000年   27篇
  1999年   3篇
  1998年   4篇
  1997年   17篇
  1996年   4篇
  1995年   4篇
  1994年   1篇
  1993年   2篇
  1992年   5篇
  1991年   7篇
  1990年   1篇
  1989年   4篇
  1986年   1篇
  1985年   1篇
  1979年   2篇
  1977年   1篇
  1976年   2篇
  1968年   1篇
  1964年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
121.
Multidrug resistance (MDR) is the major impediment to cancer chemotherapy. The expression of lung resistance-related protein (LRP), a non-ATP-binding cassette (ABC) transporter, is high in tumor cells, resulting in their resistance to a variety of cytotoxic drugs. However, the function of LRP in tumor drug resistance is not yet explicit. Our previous studies had shown that Kinesin KIF4A was overexpressed in cisplatin (DDP)-resistant human lung adenocarcinoma cells (A549/DDP cells) compared with A549 cells. The expression of KIF4A in A549 or A549/DDP cells significantly affects cisplatin resistance but the detailed mechanisms remain unclear. Here, we performed co-immunoprecipitation experiments to show that the tail domain of KIF4A interacted with the N-terminal of LRP. Immunofluorescence images showed that both the ability of binding to LRP and the motility of KIF4A were essential for the dispersed cytoplasm distribution of LRP. Altogether, our results shed light on a potential mechanism in that motor protein KIF4A promotes drug resistance of lung adenocarcinoma cells through transporting LRP-based vaults along microtubules towards the cell membrane. Thus KIF4A might be a cisplatin resistance-associated protein and serves as a potential target for chemotherapeutic drug resistance in lung cancer.  相似文献   
122.
Searching for an adequate method to investigate human development (especially the development of theoretical thinking) Vygotsky and his collaborators developed the causal genetic method. The basic idea of this method consists in the investigation of psychic functions and structures by their formation under controlled conditions (for instance via a formation experiment in classroom). But is this method also applicable in instructional settings using modern communications media?This paper is an attempt to find an answer to the question: By what means is the investigation of the formation of theoretical thinking realizable through the application of the causal-genetic method in instructional settings using hypermedia and distance learning? However, a closer examination of the question itself shows that there are three interrelated aspects, namely: the investigation and formation of theoretical thinking; distance learning using modern communications media; the causal-genetic method.It will be shown that in a formation experiment learning with a hyper-media-educational program, which is based on the theory of learning- activity, students reach a new level of cognitive development which is characterized by the growing ability of complex and dialectical thinking.  相似文献   
123.
The early identification of children with learning disabilities (LD) is difficult but can be accomplished. Observation of key behaviors which are indicators of LD by preschool and kindergarten teachers can assist in this process. This early identification facilitates the use of intervention strategies to provide a positive early experience for children at risk for academic difficulties.  相似文献   
124.
The big upper bound of typical van der Waerden number was investigated through calculating the van der Waerden number on a circle. And the van der Waerden number Wh (3,3) = 9, Wh (3,3,3)≥25 on a circle was calculated by computer.  相似文献   
125.
Data-driven decision making continues to be a growing educational reform initiative across the globe. The effective use of data requires that teachers develop the knowledge and skills to analyze and use data to improve instruction. The purpose of this article is to examine teachers’ capacity for and beliefs about data use. These issues are examined through a review of research in the past decade. We find that teachers’ beliefs about and capacity for data use are often not connected within the literature or in practice, but we argue they are the heart of the connection between data and instructional change. Teachers’ capacity to use data and their beliefs about data use are shaped within their professional communities, in training sessions, and in their interactions with coaches, consultants, and principals. However, efforts to develop teachers’ capacity for data use often fall short of their goals. Correspondingly, teachers have varied beliefs about data use, and some feel they lack the ability to use data to inform instruction. In order to be more successful, capacity building should directly address teachers’ beliefs, and data use must be decoupled from external accountability demands and involve a variety of information on student learning.  相似文献   
126.
Platelets play a vital role in the progression of atherosclerosis and thrombosis, a major cause of death worldwide. Platelets are activated by many triggers like elevated LDL in blood resulting in aggregation and formation of plaque. The purpose of this study was to investigate the effect of LDL and signal transduction inhibitor on the activation of platelets in Ischaemic risk subjects. Platelets from IHD and hyperlipidemic subjects were hypersensitive to ADP, as higher levels of platelet aggregation were observed in these groups. LDL from IHD hyperlipidemic subjects was more effective in activating platelets from any other group. Ox-LDL was more effective in activating platelets than native-LDL as monitored by level of platelet aggregation induced by PAF and thrombin. Calcium channel blocker, nifedipine and verapamil inhibited platelet aggregation at micromolar level. Protein kinase inhibitor, staurosporine was effective in inhibiting ADP induced aggregation at nanomolar level.  相似文献   
127.
128.
Urinary citric acid and calcium levels have been estimated in the urine of 20 normal healthy persons as well as 12 urinary stone patients. Inhibition efficiency of these urine samples towards the mineralisation of urinary stone forming minerals, viz., calcium phosphate, oxalate or carbonate, has been studied in an experimental model. Statistical correlation of the above data has been made by computing the coefficient of determination and unexplained variance. Clinico-biochemical indexing of calcium urolithiasis risk factor has been attempted in the light of the data.  相似文献   
129.
130.
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