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   45324篇
  免费   667篇
财政金融   7855篇
工业经济   2799篇
计划管理   7382篇
经济学   10361篇
综合类   738篇
运输经济   182篇
旅游经济   480篇
贸易经济   8666篇
农业经济   1411篇
经济概况   5453篇
信息产业经济   45篇
邮电经济   619篇
  2021年   169篇
  2020年   278篇
  2019年   375篇
  2018年   2788篇
  2017年   2568篇
  2016年   1735篇
  2015年   462篇
  2014年   680篇
  2013年   2872篇
  2012年   1213篇
  2011年   2745篇
  2010年   2419篇
  2009年   2243篇
  2008年   2289篇
  2007年   2553篇
  2006年   768篇
  2005年   1021篇
  2004年   1123篇
  2003年   1214篇
  2002年   850篇
  2001年   664篇
  2000年   646篇
  1999年   519篇
  1998年   544篇
  1997年   503篇
  1996年   516篇
  1995年   454篇
  1994年   499篇
  1993年   508篇
  1992年   471篇
  1991年   500篇
  1990年   456篇
  1989年   379篇
  1988年   388篇
  1987年   375篇
  1986年   396篇
  1985年   547篇
  1984年   518篇
  1983年   517篇
  1982年   499篇
  1981年   439篇
  1980年   423篇
  1979年   440篇
  1978年   377篇
  1977年   336篇
  1976年   268篇
  1975年   263篇
  1974年   241篇
  1973年   232篇
  1972年   190篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Without guaranteed compensation, granted by the German Renewable Energy Sources Act (Erneuerbare Energien Gesetz/EEG), biogas plants compete with all other plant types on the market for electrical energy. However, exchange-based electricity products do not currently permit an economically viable operation of biogas plants owing to their cost situation.  相似文献   
12.
13.
14.
Do local partners' network attributes affect the survival of high-tech international joint ventures (IJV)? How does the effect of network attributes vary in different subnational institutional environments? While the classic economic explanation for IJV formation and subsequent performance draws from the resource-based view (RBV), we add the relational dimension to explain that IJV survival may be affected by local partners’ relation-specific assets within the local network. We test the effect of the local partners’ network attributes as calculated by UCINET (centrality, network status, and structural hole position) on IJV survival. We additionally assert that this relationship is moderated by subnational institutional heterogeneity. Using our sample of 125 IJV dyadic pairs of US multinational enterprises (MNEs) operating in high-tech industries and their local partners in China, we find partial support for our claims.  相似文献   
15.
We explore the innovation performance benefits of alliances for spin-off firms, in particular spin-offs either from other firms or from public research organizations. During the early years of the emerging combinatorial chemistry industry, the industry on which our empirical analysis focuses, spin-offs engaged in alliances with large and established partners, partners of similar type and size, and with public research organizations, often for different reasons. We seek to understand to what extent alliances of spin-offs with other firms (either large- or small- and medium-sized firms) affected their innovation performance and also how this performance may have been affected by their corporate or public research background. We find evidence that in general alliances of spin-offs with other firms, in particular alliances with large firms, increased their innovation performance. Corporate spin-offs that formed alliances with other firms outperformed public research spin-offs with such alliances. This suggests that, in terms of their innovation performance, corporate spin-offs that engaged in alliances with other firms seemed to have benefitted from their prior corporate background. Interestingly, it turns out that the negative impact of alliances on the innovation performance of public research spin-offs was largely affected by their alliances with small- and medium-sized firms.  相似文献   
16.

We develop a dynamic model of information transmission and aggregation in social networks in which continued membership in the network is contingent on the accuracy of opinions. Agents have opinions about a state of the world and form links to others in a directed fashion probabilistically. Agents update their opinions by averaging those of their connections, weighted by how long their connections have been in the system. Agents survive or die based on how far their opinions are from the true state. In contrast to the results in the extant literature on DeGroot learning, we show through simulations that for some parameterizations the model cycles stochastically between periods of high connectivity, in which agents arrive at a consensus opinion close to the state, and periods of low connectivity, in which agents’ opinions are widely dispersed.

  相似文献   
17.
Despite the importance of good collaborative relationships in interorganisational projects, clients and contractors often develop adversarial relationships due to perceptual distance about key project issues. In this case study research, we investigated how perceptual distance emerges and changes over time, and how the collaborative relationship between client and contractor develops alongside these dynamics. In this exploration, we built upon agency theory and stewardship theory as complementary perspectives for understanding client-contractor collaborative relationships. We gathered quantitative and qualitative data in two projects, conducting three assessments in about one year. We found that perceptual distance increased and decreased over time, and that a reduction was typically associated with the collaborative relationship being characterized by stewardship rather than agency. These findings suggest that a regular assessment and evaluation of partners’ perceptions of critical project issues is warranted to timely detect and counteract perceptual distance. Moreover, partners would best adopt a stewardship orientation to reduce perceptual distance, although this may take considerable effort given the distributive nature of many pre-project negotiations.  相似文献   
18.
Sell  Friedrich L.  Stiefl  Jürgen 《Intereconomics》2021,56(4):237-242
Intereconomics - Only a few years ago, it was a widespread belief that globalisation would trigger processes of democratisation worldwide. However, even old and established democracies such as the...  相似文献   
19.
20.
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