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   6929篇
  免费   240篇
财政金融   1091篇
工业经济   326篇
计划管理   1148篇
经济学   1484篇
综合类   56篇
运输经济   32篇
旅游经济   58篇
贸易经济   1519篇
农业经济   240篇
经济概况   1000篇
邮电经济   215篇
  2023年   52篇
  2022年   39篇
  2021年   68篇
  2020年   105篇
  2019年   121篇
  2018年   308篇
  2017年   301篇
  2016年   278篇
  2015年   175篇
  2014年   264篇
  2013年   840篇
  2012年   266篇
  2011年   276篇
  2010年   313篇
  2009年   286篇
  2008年   266篇
  2007年   240篇
  2006年   179篇
  2005年   126篇
  2004年   135篇
  2003年   136篇
  2002年   139篇
  2001年   92篇
  2000年   130篇
  1999年   80篇
  1998年   98篇
  1997年   50篇
  1996年   80篇
  1995年   56篇
  1994年   73篇
  1993年   64篇
  1992年   64篇
  1991年   70篇
  1990年   73篇
  1989年   48篇
  1988年   39篇
  1987年   52篇
  1986年   52篇
  1985年   78篇
  1984年   69篇
  1983年   62篇
  1982年   65篇
  1981年   67篇
  1980年   55篇
  1979年   61篇
  1978年   60篇
  1977年   58篇
  1976年   61篇
  1975年   48篇
  1974年   34篇
排序方式: 共有7169条查询结果,搜索用时 78 毫秒
1.
In this paper we explore the micro-level determinants of conformity. Members of the social networking service Facebook express positive support to content on the website by clicking a Like button. We set up a natural field experiment to test whether users are more prone to support content if someone else has done so before. To find out to what extent conformity depends on group size and social ties we use three different treatment conditions: (1) one stranger has Liked the content, (2) three strangers have Liked the content, and (3) a friend has Liked the content. The results show that one Like from a single stranger had no impact. However, increasing the size of the influencing group doubled the probability that subjects expressed positive support. Friendship ties were also decisive. People were, on average, four times more likely to press the Like button if a friend, rather than a stranger, had done so before them. The existence of threshold effects in our experiment clearly shows that both group size and social proximity matters when opinions are shaped.  相似文献   
2.
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   
3.
4.
In this article I argue that the quest to establish digital innovation as a research domain is hindered by three challenges. As digital innovation research we are too often: a) reifying the agency of digital innovation actors; b) developing explanations of digital innovation detached from the specifics of digital technology, and c) developing overly specific explanations of digital innovation. I begin by providing a brief overview of the recombination perspective and considering why this perspective holds great appeal in the digital age. I then engage with Henfridsson et al.'s (2018) value spaces framework as a platform for framing value creation and value capture in relation to recombination in digital innovation. Next, I push Henfridsson et al.'s arguments one step further to discuss them in relation to what I consider to be the key challenges for digital innovation research. Illustrating with some of my own recent projects, I suggest that in order to fully address these challenges we need to (1) develop explanations of digital innovation acknowledging the complexity of sociomaterial interaction in digital innovation; (2) develop explanations of digital innovation building on the specifics of digital technology, and (3) develop explanations of digital innovation based on an oscillation between the specific and the general. The article concludes by pointing to future challenges and developments for digital innovation research.  相似文献   
5.
State-owned enterprises (SOEs) are commonly associated with undue advantages due to preferential treatment by the state. Simultaneously they are often quoted as handicapped given the notorious state interference, management problems and agency tensions. They used to be regarded as a mainly domestic issue but in the context of globalisation and the fact that states enter treaties with new obligations, SOEs’ performance ceased to be solely a domestic problem, increasingly so as state-owned multinational enterprises (SOMNEs) emerge. This article presents the results of research on Polish SOEs’ outward foreign direct investment (OFDI). It offers an overview of overseas activities of nine major Polish firms with a state stake and aims to contribute to the conceptual literature on foreign investments conducted by SOMNEs. We distinguish between FDI by SOMNEs as specific – privileged (facilitated) or discriminated (hampered) – investments subject to the home country’s state power and the host country’s state perception.  相似文献   
6.
7.
Two decades ago, the rules governing the provision of piped municipal water supply in Mumbai became linked to the policy frameworks governing eligibility for a property titling scheme. This article outlines the ideological basis and practical implications of the shift, as well as the contradictions of the new regulatory regime. The article demonstrates how these contradictions have been mediated by the material and practical knowledge, embodied expertise, local authority and wide‐ranging socio‐political work of two sets of actors: municipal water engineers and a cast of characters known locally as ‘plumbers’. The social, political and hydraulic imaginaries animating the work of ‘plumbing’ are bound up with a temporal and spatial imaginary distinctly at odds with the network‐flow conception of hydraulic engineering within which the work of water supply planning and distribution in Mumbai is conceptualized, materialized and institutionalized. The hydraulic and legal contradictions of these clashing infrastructural idioms––of flow and event––have rendered the regulatory framework highly unstable. These contradictions eventually erupted in Mumbai's waterscape, leaving the city's water infrastructures suspended in a highly politicized state of limbo between dueling infrastructural imaginaries.  相似文献   
8.
Various aspects of sustainable development and quality of life are considered, including the impact of standardization. Particular attention is paid to the study of the role played by standardization in improving environmental protection. In this connection the significance of standardization is shown as a factor of improving the technological potential of an enterprise and the quality of life. Various approaches to methods for assessing the effective impact of standardization on the quality of life are analyzed.  相似文献   
9.
The general consensus in the volatility forecasting literature is that high-frequency volatility models outperform low-frequency volatility models. However, such a conclusion is reached when low-frequency volatility models are estimated from daily returns. Instead, we study this question considering daily, low-frequency volatility estimators based on open, high, low, and close daily prices. Our data sample consists of 18 stock market indices. We find that high-frequency volatility models tend to outperform low-frequency volatility models only for short-term forecasts. As the forecast horizon increases (up to one month), the difference in forecast accuracy becomes statistically indistinguishable for most market indices. To evaluate the practical implications of our results, we study a simple asset allocation problem. The results reveal that asset allocation based on high-frequency volatility model forecasts does not outperform asset allocation based on low-frequency volatility model forecasts.  相似文献   
10.
We comprehensively analyze the predictive power of several option-implied variables for monthly S&P 500 excess returns and realized variance. The correlation risk premium (CRP) and the variance risk premium (VRP) emerge as strong predictors of both excess returns and realized variance. This is true both in- and out-of-sample. Our results also reveal that statistical evidence of predictability does not necessarily lead to economic gains. However, a timing strategy based on the CRP leads to utility gains of more than 5.03% per annum. Forecast combinations provide stable forecasts for both excess returns and realized variance, and add economic value.  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