全文获取类型
收费全文 | 776篇 |
免费 | 39篇 |
出版年
2023年 | 13篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 13篇 |
2019年 | 28篇 |
2018年 | 26篇 |
2017年 | 38篇 |
2016年 | 39篇 |
2015年 | 29篇 |
2014年 | 27篇 |
2013年 | 193篇 |
2012年 | 30篇 |
2011年 | 26篇 |
2010年 | 24篇 |
2009年 | 28篇 |
2008年 | 16篇 |
2007年 | 18篇 |
2006年 | 19篇 |
2005年 | 10篇 |
2004年 | 15篇 |
2003年 | 14篇 |
2002年 | 12篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1995年 | 7篇 |
1994年 | 11篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1978年 | 8篇 |
1977年 | 3篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1969年 | 5篇 |
排序方式: 共有815条查询结果,搜索用时 78 毫秒
71.
This paper explores the reasons why cities are often major centres of innovation, even in some less favoured regions and countries. It starts with an anatomization of the dominant factors that explain why key less favoured settings developed 'new economy' clusters through institutional interaction with Silicon Valley. The analysis concludes that public research resources and private commercialization funding are central, supported by a wide array of private but few public innovation support services. It then examines a number of cases from cities in less favoured regions and countries where innovation has occurred. The conclusions are that the research-venture capital model is present and explains innovation in each case. However, in some cases public venture capital has to substitute for private due to market failure, or a phenomenon termed 'Silicon Valley Offshore' has been induced. Cities are innovative where they concentrate the desired scientific and investment knowledge capabilities. 相似文献
72.
73.
74.
75.
76.
77.
78.
One purpose of the Advocacy Coalition Framework (ACF) is to explain policy change. Previous holistic reviews of the ACF by Weible, Sabatier, and McQueen (2009) and Pierce, Peterson, Jones, Garrard, and Vu (2017) of the framework have not explicitly analyzed all the concepts and their interactions in a systematic manner. To address this gap and inform scholars and practitioners about past findings, strengths, weaknesses, and opportunities for future research, this article analyzes how the ACF's theory of policy change is applied to 148 policy processes among 67 journal articles from 2007 to 2014. Similar to Weible et al. (2009), this research finds the frequent use of multiple primary pathways to policy change, infrequent use of many of the ACF's concepts, a plurality of applications in the environment and energy domain, comparison of subsystems, and a need for greater clarity and transparency among applications. Unlike Weible et al. (2009), this article explores associations between primary pathways and policy domains, the frequency of associations between primary pathways and secondary components, policy change and stasis, and identifies threats to internal validity of key ACF concepts. 相似文献
79.
80.