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   8207篇
  免费   0篇
各国政治   203篇
工人农民   1071篇
世界政治   173篇
外交国际关系   284篇
法律   4630篇
政治理论   1844篇
综合类   2篇
  2021年   1篇
  2020年   3篇
  2019年   2篇
  2018年   1272篇
  2017年   1198篇
  2016年   1011篇
  2015年   57篇
  2014年   15篇
  2013年   18篇
  2012年   181篇
  2011年   911篇
  2010年   1011篇
  2009年   580篇
  2008年   729篇
  2007年   686篇
  2006年   2篇
  2005年   58篇
  2004年   165篇
  2003年   137篇
  2002年   26篇
  2001年   1篇
  2000年   4篇
  1998年   10篇
  1997年   11篇
  1996年   19篇
  1995年   28篇
  1994年   23篇
  1993年   1篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1984年   9篇
  1983年   8篇
  1982年   5篇
  1979年   5篇
  1978年   7篇
  1977年   9篇
  1974年   1篇
排序方式: 共有8207条查询结果,搜索用时 31 毫秒
981.
982.
983.
984.
985.
986.
987.
988.
This study focuses on regional entrepreneurial ecosystems and offers a complex model of start-ups, Regional Entrepreneurship and Development Index (REDI) and six domains of the entrepreneurial ecosystem (culture, formal institutions, infrastructure and amenities, IT, Melting Pot and demand). Altogether they capture the contextual features of socioeconomic, institutional and information environment in cities. To explain variations in entrepreneurship in a cross-section of 70 European cities, we utilize exploratory factor analysis and structural equation modelling for regional systems of entrepreneurship using individual perception surveys by Eurostat and the REDI. This study supports policymakers and scholars in development of new policies conducive to regional systems of innovation and entrepreneurship and serves as a basis for future research on urban entrepreneurial ecosystems.  相似文献   
989.
We study the economic value of both embodied technological change and Research and Development (R&D) investment as proxies for the inputs of innovative activities conducted by Vietnamese firms. Our main focus is on the profitability of young innovative companies (YICs), private innovative companies (PICs), and small and young companies (SYCs). In particular, we test whether YICs could prove successful in fostering economic development through their technological change activities. Results show that (a) although YICs are more R&D intensive and innovative than PICs and SYCs, in general they do not produce equivalent performance; however those specific YICs focusing on technological change potentially outperform their counterparts, and (b) PICs are more capable than the other types of firms in translating their innovative effort to higher profitability.  相似文献   
990.
In the entrepreneurial economy of today, it is not the multinational firms which are the predominant driver in the creation of new knowledge, but the individual entrepreneur. Correspondingly, new ventures of small size are leading in commercializing new knowledge and transferring it to the market. This economic shift has been reflected by broad entrepreneurship policies, which aim at supporting the individual on the challenge of a high-growth start-up. However, prior experience shows that uniform entrepreneurship policies do not address the individual needs in different countries and ecosystems adequately. In this paper, we study the performance of academic spin-offs that received public funding from the German EXIST Business Start-Up Grant, a support program which aims at increasing the number of innovative start-ups from academia. Using a control group matching approach, we provide evidence that these start-ups are smaller by two full time equivalent employees, generate 1.7 times higher losses and have a nearly three times lower return on capital than science-based entrepreneurial firms with comparable characteristics in the first 5 years after foundation. We interpret these results to be primarily caused by the inferior financial contracting structure of the program compared to private venture capital funding and by the resulting adverse selection and incentive effects on the entrepreneurs. The evidence calls for rethinking public interventions in a national system of entrepreneurship.  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