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   2964篇
  免费   8篇
  国内免费   1篇
教育   2028篇
科学研究   543篇
各国文化   1篇
体育   98篇
综合类   7篇
文化理论   62篇
信息传播   234篇
  2022年   3篇
  2021年   19篇
  2020年   3篇
  2019年   4篇
  2018年   55篇
  2017年   102篇
  2016年   167篇
  2015年   117篇
  2014年   55篇
  2013年   71篇
  2012年   154篇
  2011年   171篇
  2010年   83篇
  2009年   32篇
  2008年   68篇
  2007年   58篇
  2006年   50篇
  2005年   688篇
  2004年   471篇
  2003年   300篇
  2002年   134篇
  2001年   65篇
  2000年   31篇
  1999年   25篇
  1998年   5篇
  1997年   4篇
  1996年   5篇
  1995年   3篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   4篇
  1988年   1篇
  1987年   5篇
  1986年   1篇
  1985年   1篇
  1984年   3篇
  1983年   1篇
  1981年   2篇
  1977年   1篇
  1976年   2篇
  1975年   2篇
排序方式: 共有2973条查询结果,搜索用时 15 毫秒
11.
12.
The configuration of the novel three-stage L-band erbium-doped fiber amplifier with very large and flat gain and very low noise figure presented in this paper uses the forward ASE (amplified spontaneous emission) from the first section of the EDF (erbium-doped fiber) and the backward AS E from the third section of the EDF (both serve as the secondary pump sources of energy) to pump the second EDF. To improve the pump efficiency, the power of the pump is split into two parts(with a ratio of e.g. 2:7). The characteristics of this L-band EDFA are studied on the basis of the Giles Model with ASE.  相似文献   
13.
This mixed-methods research compared job satisfaction among counselors working in pre-schools and primary-schools. Its quantitative phase included 223 counselors, 70 of whom also participated in the qualitative phase. A demographic information form, job-satisfaction scale and a semi-structured interview protocol were used to collect data. Quantitative analysis indicated that the primary-school counselors’ job satisfaction was higher than that of the pre-school counselors. There were no statistically significant differences in satisfaction between the two groups based on gender, age, or marital status, or the interaction of any of those three demographic factors with the type of school where they worked. In the qualitative phase, approximately half of the primary-school counselors but just one-third of the pre-school counselors reported their job satisfaction as being high; and around half of the pre-school group and one-third of the primary-school group reported that school type where they worked had a negative impact on their job satisfaction.  相似文献   
14.
This paper addresses a neglected topic in the knowledge management literature: how the size of a network of actors affects the nature of intra-network social relations and knowledge processes. It makes a theoretical contribution to developing understanding in this area drawing on a range of literatures including practice-based perspectives on knowledge, the literature on the embeddedness of social relations, and relevant knowledge management literature. The central focus of this paper is on the relationship between network size, network density, and how these variables affect intra-network knowledge processes. It suggests that as network size increases network density is likely to decrease (as it becomes problematic for the actors in such networks to retain strong ties with a significant proportion of the network's members), which it will be suggested has significant ramifications for intra-network knowledge processes. This paper concludes by reflecting on the implications of the ideas developed for network-based forms of organizing, and innovation processes.  相似文献   
15.
导师如何通过“因材施教”的指导提升博士生的创新能力,是博士生培养的关注热点。基于481份“双一流”建设高校理工科博士生的调查数据,从导生双主体角度,以控制和支持两个维度的导生组合类型为自变量、博士生年级为调节变量,探索二者对理工科博士生创新能力的影响机制。研究发现,相较于导师低控制和学生低投入、导师低支持和学生低投入,其他导生组合类型均对理工科博士生的创新能力具有显著正向影响。年级在控制维度的导生组合类型对理工科博士生创新能力的影响中起调节作用。研究结果验证了导师阶段式培养的重要性,同时强调了博士生作为学习主体的关键性。  相似文献   
16.
Pigeons' keypecking was reinforced by food on baseline schedules of multiple variable interval (VI) x VI x and on contrast schedules of multiple VI x VI y. Deprivation of food was varied by maintaining subjects at 75%, 85%, and 95% (+/- 2%) of their free-feeding weights. Positive and negative behavioral contrast were observed. The size of the contrast was not systematically altered by changes in deprivation. Positive and negative contrast were both larger later in the session than they were earlier. Within-session decreases in responding were steeper for the baseline than for the contrast schedules for positive contrast. Within-session decreases were steeper for the contrast than for the baseline schedules for negative contrast. These results were predicted by the idea that different amounts of habituation to the reinforcer during the baseline and contrast schedules contribute to behavioral contrast. The results show that contrast occurs under conditions that reduce the effect of the following component. The results support the assumption that positive and negative contrast are produced by symmetrical theoretical variables.  相似文献   
17.
Today all parties within the health-care system demand more information and evidence to take more efficient and pinpointed management decisions. Their goal is a better patient and patient-care management. This paper presents an information visualisation approach to discover knowledge for the management of tele-home care for the elderly using the video-telephone: what type of elderly need what type of video-telephone interventions? This document focuses on the synthesis aspects of data mining with a view to knowledge discovery: the global, holistic, synthesis approach. More specifically, it summarises visually the relationships among the types of video-telephony care, among the segments of elderly, and between the types of interventions and the segments of elderly simultaneously. The graphical display allows delineating areas that group elderly with a similar/dissimilar video-telephony care profile. Information visualisation is a promising approach to provide insight into large multidimensional data sets. It fosters knowledge discovery.  相似文献   
18.
In this paper, social network analysis techniques and regression models are used to explain the impact of the level of knowledge development on ego-network redundancy in a community of hospital physicians. Our findings document that the level of knowledge development and the extent to which knowledge is homogeneously distributed amongst collaborating physicians are related to the redundancy of their advice networks, albeit with opposite effects. Our results highlight also that the impact of these relationships on network redundancy is moderated based on whether partnering individuals belong to different professional groups. Our results provide valuable input for the management of knowledge networks within professional organizations.  相似文献   
19.
Despite the large volume of research and managerial literature on knowledge management, many practitioners seem to find it difficult to appreciate its added value for their managerial work. This paper aims to understand and elaborate the added value that knowledge management as a managerial approach can bring to the management of knowledge-intensive organizations. This study explores empirically the actual management practices of a knowledge-intensive organization and examines how knowledge-related phenomena are managed as embedded aspects of management. This paper makes a contribution to prior discussions concerning the relevance of knowledge management and the role of knowledge management as an embedded management practice. The findings of this study should be useful in explaining practitioners the nature, relevance and value of knowledge management.  相似文献   
20.
This paper provides an overview of the knowledge management systems (KMSs) adopted by small and medium enterprises (SMEs). KMSs are divided into two categories: knowledge management tools (KM-Tools) and knowledge management practices (KM-Practices). On the basis of the analysis of the literature, two research questions (RQs) were identified and addressed through semi-structured interviews carried out in a sample of 35 SMEs operating in high-tech industries. The first RQ concerns the degree of adoption of KMSs by SMEs. The second RQ regards the relationship between KM-Tools and KM-Practices. As far as the degree of adoption of KMSs, the paper highlights that SMEs are not a homogeneous world but there are a variety of approaches and behaviours. As far as the relationship between the degree of adoption of KM-Tools and KM-Practices, the paper identifies three groups of SMEs that seem to point out the stages of the process of adoption of KMSs: Introduction, SMEs that deal with the process of knowledge management exploiting practices and tools that are already known; Growth, SMEs that adopt specialist practices of knowledge management acquiring new organisational and managerial competence in the field of knowledge management; Maturity, SMEs that invest in new technology and that acquire new technological competence in the field of knowledge management. This categorisation paves the way for further theoretical and practical implications for both managers and policy makers.  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