全文获取类型
收费全文 | 104篇 |
免费 | 1篇 |
专业分类
教育 | 72篇 |
科学研究 | 13篇 |
体育 | 4篇 |
文化理论 | 3篇 |
信息传播 | 13篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 7篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 6篇 |
2013年 | 7篇 |
2012年 | 6篇 |
2011年 | 2篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 10篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 3篇 |
2001年 | 12篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1991年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1969年 | 2篇 |
1962年 | 1篇 |
1942年 | 1篇 |
排序方式: 共有105条查询结果,搜索用时 15 毫秒
101.
Electricity supply is a large technical system, which exhibits strong path dependencies and high barriers for radical innovations. Recent market liberalization, however, has initiated a fundamental restructuring. The paper analyzes how liberalization has altered innovation processes in the field of electricity supply. We examine three radical innovations under monopoly conditions and contrast the findings with the results from a survey on the innovation behavior of electric utilities in liberalized markets. We argue that the selection environment for innovations has changed in various respects. In our sample, new options open to innovation activities have emerged at the level of the firm and utility strategies turn out to be more heterogeneous. This may be interpreted as an increase in the variety of search processes, which may lead to a mid-term decrease of path-dependencies. 相似文献
102.
This paper examines how foreign-owned and domestically owned firms transform innovation into employment growth. The empirical analysis, based on the model of Harrison et al. (2008) and CIS data for 16 countries, reveals important differences between the two groups: Due to general productivity increases and process innovation, foreign-owned firms experience higher job losses than domestically owned firms. At the same time, employment-creating effects of product innovation are larger for foreign-owned firms. Together with employment-stimulating effects stemming from existing products, they overcompensate the negative displacement effects resulting in net employment growth in foreign-owned firms. However, net employment growth turns out to be smaller in foreign-owned firms than in domestically owned firms. 相似文献
103.
Klaus-Dieter Schewe Bernhard Thalheim Aleksander Binemann-Zdanowicz Roland Kaschek Thomas Kuss Bernd Tschiedel 《Education and Information Technologies》2005,10(1-2):83-110
Starting from a general framework for web-based e-learning systems that is based on an abstraction layer model, this paper presents a conceptual modelling approach, which captures the modelling of learners, the modelling of courses, the personalisation of courses, and the management of data in e-learning systems. Courses are modelled by outline graphs, which are further refined by some form of process algebra. The linguistic analysis of word fields referring to an application domain helps to set up these course outlines. Learners are modelled by classifying value combinations for their characteristic properties. Each learner type gives rise to intentions as well as rights and obligations in using a learning system. Intentions can be formalised as postconditions, while rights and obligations lead to deontic constraints. The intentions can be used for the personalisation of the learning system to a learner type. Finally, the management of data in an e-learning system is approached on two different levels dealing with the content of individual learning units and the integrated content of the whole system, respectively. This leads to supporting databases and views defined on them. 相似文献
104.
105.
Why space matters in technological innovation systems—Mapping global knowledge dynamics of membrane bioreactor technology 总被引:1,自引:0,他引:1
Studies on technological innovation systems (TISs) often set spatial boundaries at the national level and treat supranational levels as a geographically undifferentiated and freely accessible global technological opportunity set. This article criticizes this conceptualization and proposes instead to analyze relevant actors, networks and processes in TIS from a relational perspective on space. It develops an analytical framework which allows investigating innovation processes (or ‘functions’) of a TIS at and across different spatial scales. Based on social network analysis of a co-publication dataset from membrane bioreactor technology, we illustrate how the spatial characteristics of collaborations in knowledge creation vary greatly over relatively short periods of time. This finding suggests that TIS studies should be more reflexive on system boundary setting both regarding the identification and analysis of core processes as well as in the formulation of policy advice. 相似文献