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   1624篇
  免费   27篇
  国内免费   16篇
教育   1157篇
科学研究   181篇
各国文化   18篇
体育   177篇
综合类   28篇
文化理论   14篇
信息传播   92篇
  2023年   4篇
  2022年   21篇
  2021年   24篇
  2020年   33篇
  2019年   49篇
  2018年   69篇
  2017年   61篇
  2016年   64篇
  2015年   34篇
  2014年   44篇
  2013年   180篇
  2012年   60篇
  2011年   47篇
  2010年   39篇
  2009年   43篇
  2008年   42篇
  2007年   55篇
  2006年   59篇
  2005年   50篇
  2004年   52篇
  2003年   92篇
  2002年   124篇
  2001年   115篇
  2000年   68篇
  1999年   24篇
  1998年   14篇
  1997年   18篇
  1996年   11篇
  1995年   14篇
  1994年   10篇
  1993年   13篇
  1992年   7篇
  1991年   9篇
  1990年   10篇
  1989年   4篇
  1988年   4篇
  1987年   9篇
  1986年   4篇
  1985年   9篇
  1984年   8篇
  1983年   4篇
  1982年   7篇
  1980年   4篇
  1978年   8篇
  1974年   3篇
  1973年   4篇
  1972年   3篇
  1967年   4篇
  1887年   3篇
  1865年   4篇
排序方式: 共有1667条查询结果,搜索用时 0 毫秒
21.
Spelling skills have been identified as one of the major barriers to written text production in young English writers. By contrast oral language skills and text generation have been found to be less influential in the texts produced by beginning writers. To date, our understanding of the role of spelling skills in transparent orthographies is limited. The current study addressed this gap by examining the contribution of spelling, oral language and text generation skills in written text production in Italian beginner writers. Eighty-three children aged 7–8 years participated in the study. Spelling, lexical retrieval, receptive grammar, and written sentence generation and reformulation skills were assessed and children were asked to write a text on a set topic. A factor analysis revealed that the children’s written text production was captured by three factors: productivity, complexity and accuracy. In contrast to results from children learning to write in opaque orthographies, such as English, this study showed that receptive grammar and written sentence generation skills accounted for significant variance in measures of productivity, complexity and accuracy in Italian children’s written text production. Spelling skills contributed to text accuracy and quality and explained more variance than receptive grammar in microstructural accuracy. By contrast, oral grammatical skills explained more variance in text quality than spelling. The current study shows the differential impact of language systems, such as Italian, on written text production. Implications for assessment and instruction are outlined.  相似文献   
22.
关于风险投资者和投资管理机构的关系模型   总被引:2,自引:0,他引:2  
陈德棉  李刚  张玉臣 《预测》2001,20(6):52-53
由于信息不对称,风险投资管理机构存在很大的道德风险。本文通过风险投资者和投资管理机构之间的关系研究认为,使投资管理者的回报和基金收益挂钩和公布投资管理者的业绩信息,可以对投资管理者进行有效的激励和约束。  相似文献   
23.
Since the turn of the century large groups of former institutionalised children have exercised their right to see their ‘personal files’, and this has drawn widespread attention to these documents and their potential in scholarly research. This article explores the meanings of personal files from the period 1945–1984 as sources for both historical researchers and adult care leavers themselves, in the context of the orphanages in Ghent, Belgium. Based on the experiences of those who have consulted their files, we come to the conclusion that the personal files of the Ghent orphans provide some new information but, at the same time, leave a lot of issues unresolved. Although the files offered significant insights for researchers studying the most recent period in the history of the Ghent orphanages, it is difficult to see them as ‘keys to the past’ for former orphans who are trying to (re)construct their own, individual life histories.  相似文献   
24.
This article presents a comparative analysis of the determinants of early school leaving (ESL) at the country level. We decompose ESL rates into two components: a ‘primary’ rate reflecting unqualified school leaving from initial education, and a second component accounting for early school leavers who participate in training programmes. Both may be influenced by structural and policy determinants. We examine how the ESL rate is affected by macro-economic and social context variables such as GDP/capita, growth, poverty, and youth unemployment, as well as system characteristics of the education system (such as legal school leaving age, grade retention, early tracking, and size of vocational education) and the labour market and social protection systems (minimum wages, unemployment insurance).  相似文献   
25.
This article considers the transmission of knowledge in higher education. It takes the metaphor of the music industry that pre‐selects the music people can buy. The sales potential is the leading principle in the selection process. Often the small producer is excluded because his or her music is not of commercial interest. The end‐customer does not know what he or she is missing because he or she has never heard the music. It is to be feared that a similar market principle will also influence the selection of knowledge and affect the capacity of higher education institutions to freely generate and transmit new knowledge. The globalization of higher education risks homogenizing the cultural traditions of the non‐Western world through a process of Western cultural domination. On the other hand, the Internet, via open source software like LINUX, might serve to democratize higher education and allow greater grassroots input.  相似文献   
26.
We investigated Dutch word stress acquisition in 3‐year‐old children at risk of dyslexia (children with at least one parent or older sibling with reading difficulties) and normally developing children, in order to shed light on language acquisition delays in children at risk of dyslexia, as well as to investigate further phonological deficits in dyslexia. The children had to repeat non‐words with stress patterns varying in regularity. Both the at‐risk and control children performed better on imitation of regular stress targets and worse on irregular and prohibited stress patterns. However, the at‐risk children showed more difficulty imitating irregular and prohibited patterns, and had lower percentages phonemes correct than the control group. The results can be interpreted as a delay in word stress acquisition in the at‐risk group. The findings thus point towards a phonological deficit early in language development.  相似文献   
27.
论矿物材料计算与设计   总被引:5,自引:0,他引:5  
矿产资源产业是国民经济的基础产业,非金属矿产是重要的固体矿产之一,80%的矿物用于材料工业,矿物加工是矿产资源高效利用、制备矿物材料的重要加工技术环节,矿物材料是国民经济中高新技术材料的重要组成,材料科学及矿物材料学科的发展,为矿物材料计算与设计理论的提出奠定了实际基础.借鉴材料设计与计算的理论和方法,在总结、分析和研究矿物加工及矿物材料制备方面大量的理论研究和实际成果的基础上,提出了矿物材料计算与设计及功能性矿物材料、复合材料化学改性药剂分子设计与模拟的学术思想,论述了矿物材料计算与设计的基本科学技术问题、研究内容、相关学科体系、研究层次及其学科地位.其意义在于:使矿物加工工程学科发展和功能性矿物材料的研发,建立在基本科学原理基础之上,将矿物加工工程学科的主要研究内容统一在总体的方向、目标之内,横向拓展了相关学科理论的研究范围;根据矿物结构、组成,通过设计与计算,对矿物材料性能进行预测、预报,进而为制备提供最佳技术路线;对于已知性能的矿物材料优化制备路线,系统分析各种矿物的结构与组成及其所具备固有性质,针对各种材料性质要求,排列对应关系,为复合材料的制备奠定基础,进而实现矿物资源的高效开发和利用,同时,使得材料设计或计算材料的学科基础向研究矿物组成与结构的纵向延伸,丰富了材料科学思想.  相似文献   
28.
ABSTRACT

The objective of this study was to analyse the effect of the use of social networks in smartphones or playing video games on the passing decision-making performance in professional soccer athletes. Participants were 25 male professional soccer athletes (mean ± SD: age 23.4 ± 2.8 years). The participants performed three randomised conditions divided into three groups: control (CON), smartphone (SMA), and video game (VID). Before and after each experimental condition, the Stroop Task assessed the level of induced mental fatigue. Then, the athletes performed a simulated soccer match. A CANON® camera recorded the matches for further analysis on passing decision-making performance. A group effect was identified (< .01) with impairment on passing decision-making performance for the SMA (p = .01, ES = 0.5) and VID (p = .01, ES = 0.5) conditions. We concluded that the use of social networks on smartphones and/or playing video games right before official soccer matches might impair the passing decision-making performance in professional soccer athletes.  相似文献   
29.
研究假设是研究课题确定后依据一定的知识、事实和资料,对所研究问题的规律或原因做出的推测性论断和假定性说明,是研究之前预先设想的、暂时的理论,是对研究课题设想出的一种或几种可能的结论或答案。假设一般包括两个事件或概念之间的关系,用“如果……那么……”的句子来陈述。例如:如果教师对一名学生的评价越来越差,那么该生的自我评价也会变得越来越差。研究假设是我们在实施课题研究设计之前,必须明确的问题。在教育科学研究中,提出具体的研究假设具有非常重要的作用。一、为课题研究指明方向研究假设使研究目的更明确,研究范围更确…  相似文献   
30.
假日旅游经济是我国旅游经济发展中的一个新的增长点。本文对假日旅游经济的涵义、基本特征及产生的背景进行了论述,并提出了科学调控假日旅游经济的若干对策措施,以期有益于促使我国假日旅游经济持续、健康发展。  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