全文获取类型
收费全文 | 8344篇 |
免费 | 0篇 |
专业分类
各国政治 | 208篇 |
工人农民 | 1068篇 |
世界政治 | 172篇 |
外交国际关系 | 282篇 |
法律 | 4747篇 |
政治理论 | 1867篇 |
出版年
2018年 | 1270篇 |
2017年 | 1196篇 |
2016年 | 1011篇 |
2015年 | 56篇 |
2014年 | 16篇 |
2013年 | 13篇 |
2012年 | 189篇 |
2011年 | 918篇 |
2010年 | 1017篇 |
2009年 | 587篇 |
2008年 | 748篇 |
2007年 | 721篇 |
2006年 | 13篇 |
2005年 | 66篇 |
2004年 | 170篇 |
2003年 | 141篇 |
2002年 | 36篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 13篇 |
1997年 | 18篇 |
1996年 | 20篇 |
1995年 | 33篇 |
1994年 | 23篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1986年 | 3篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有8344条查询结果,搜索用时 15 毫秒
981.
982.
983.
984.
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
985.
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
986.
Mark R. Ayoub Sandra Gottschalk Bettina Müller 《The Journal of Technology Transfer》2017,42(5):1100-1124
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
987.
Research underlines the importance of socio-cultural factors when establishing a supportive environment for innovation and entrepreneurship growth. Scholars discuss different aspects, ranging from cultural attitudes and religious norms, to aspects of tolerance and social freedom. Following on research tradition, this paper analyzes the freedom-innovation relationship using a hand collected data set of 57 countries and the 50 U.S. states over a 3 year period. We argue and test whether the slope of the freedom-innovation link is shaped by and trades-off the costs and benefits of either weak or strong social ties within a country. Our empirical findings support a positive relationship between the freedom-innovativeness-slope, but not a negative or inverted U-shaped relationship. 相似文献
988.
This article seeks to address two fundamental questions: (1) Does social capital (SC) embedded in global buyer–supplier (GBS) relationships enhance local firms’ potential absorptive capacity (PAC) and realized absorptive capacity (RAC)? And (2) What are the effects of local firms’ PAC and RAC on their innovation outcomes? Based on survey data collected from 297 Chinese firms engaged in GBS cooperation in China’s Yangtze River Delta region, we test our research hypotheses with the structural equation modelling approach. The empirical findings indicate that both structural and relational SC are important antecedents of PAC and RAC in global buyer–supplier relationships. More specifically, RAC not only improves local suppliers’ new product performance, but also fully mediates the relationship between PAC and new product performance. Our results have two major implications for practicing managers. First, local suppliers in emerging economies need to pay more attention to SC embedded in GBS relationships for it is an important means for them to overcome resource constraints and therefore to improve their new product performance. Second, it is important for managers in local firms to continuously improve their PAC to better assess and assimilate external knowledge, and extend their RAC to upgrade their interpretation and comprehension of commercialization possibilities, which allows for generating synergy of knowledge recombination with existing core competencies. 相似文献
989.
Kathryn Rudie Harrigan Maria Chiara DiGuardo 《The Journal of Technology Transfer》2017,42(6):1334-1361
Patents have long been assumed to provide firms with competitive advantage, but longitudinal results suggest that some types of patent content provide more enduring advantage than others do. The duration of advantage appeared to wane with time in the highly-dynamic U.S. communications-services industry during a period when technological changes occurred rapidly within it (1998–2012). Results suggest patents integrating technology streams that were different from the technologies of focal-patents’ grants contributed more to sustaining firms’ profit margins during this period than did focal patents that exploited extant technological knowledge. We found that firms who continually pushed their organization’s knowledge envelope outward to incorporate more unknown technologies sustained higher profit margins for a longer duration of time than did firms whose patented inventions were predominantlyincremental—even within difficult settings where competition grew so intense that firms’ average operating margins were deteriorating. 相似文献
990.
André De Zutter Robert Horselenberg Peter J. van Koppen 《Journal of Police and Criminal Psychology》2017,32(2):114-127
A study was conducted to test whether it is possible to build a model to distinguish true and false allegations of rape based on the theory of fabricated rape. The theory is based on the principle that a false complainant of rape has not been raped and has to fabricate a story while the story of a true victim is based on recollections of the event. Consequently, false complainants will behave as liars do, construct their story based on their own sexual experiences and on mental representations, beliefs of how such a crime would happen (De Zutter et al. in Eur J Psychol Appl Leg Context. doi: 10.1016/j.ejpal.2016.02.002, 2016). To test the theory and to build a model to discriminate between true and false allegations of rape, a police sample of true and false allegations was studied. A total of 129, 72 true and 57 false, allegations of rape fulfilled the stringent criteria of the current study, among others on ground truth. Fifty-four allegations of rape, 27 true and 27 false, were used to build a prediction model based on the theory of bounded rationality by Gigerenzer (2002). The remaining 75 cases, 45 true and 30 false, were blindly categorised as either true or false based on the model. The model was able to predict the true nature of the majority of allegations with an accuracy rate of 91 %. Thus, it seems possible to discriminate to a considerable extend between true and false allegations of rape. 相似文献