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   48856篇
  免费   1485篇
  国内免费   182篇
财政金融   6894篇
工业经济   3010篇
计划管理   7996篇
经济学   9088篇
综合类   1610篇
运输经济   285篇
旅游经济   563篇
贸易经济   6219篇
农业经济   2334篇
经济概况   5889篇
水利工程   6528篇
信息产业经济   3篇
邮电经济   104篇
  2023年   297篇
  2022年   465篇
  2021年   766篇
  2020年   774篇
  2019年   749篇
  2018年   982篇
  2017年   1070篇
  2016年   989篇
  2015年   903篇
  2014年   1299篇
  2013年   3822篇
  2012年   2369篇
  2011年   2898篇
  2010年   2391篇
  2009年   2123篇
  2008年   2269篇
  2007年   2187篇
  2006年   2141篇
  2005年   1985篇
  2004年   1265篇
  2003年   970篇
  2002年   902篇
  2001年   885篇
  2000年   764篇
  1999年   718篇
  1998年   659篇
  1997年   595篇
  1996年   591篇
  1995年   519篇
  1994年   553篇
  1993年   552篇
  1992年   526篇
  1991年   531篇
  1990年   479篇
  1989年   411篇
  1988年   404篇
  1987年   403篇
  1986年   395篇
  1985年   582篇
  1984年   546篇
  1983年   553篇
  1982年   534篇
  1981年   460篇
  1980年   445篇
  1979年   459篇
  1978年   392篇
  1977年   343篇
  1976年   292篇
  1975年   266篇
  1974年   248篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Gao  Zehai  Liu  Yang  Li  Nan  Ma  Kangjie 《Water Resources Management》2022,36(8):2685-2702
Water Resources Management - Urban river not only has the important function in urban hydrological environment, but also is an area for entertainment. Water quality assessment is the core technique...  相似文献   
2.
3.
4.
Differences in accrued gains and investors’ tax-sensitivity induce variation in a capital gains lock-in effect across mutual funds even for the same stock at the same time. Exploiting this variation, we show this effect influences funds’ governance decisions: higher capital gains decrease the likelihood a fund exits prior to contentious votes and increase the likelihood a fund votes against management. Consistent with tax motivation, these findings are concentrated among funds with tax-sensitive investors. Further, high aggregate capital gains across funds holding a stock predict a higher likelihood management loses a vote and a lower likelihood a contentious vote is proposed.  相似文献   
5.
Growing urbanisation in South Africa is reflected in burgeoning Working class and informal township settlements on the fringes of its major towns and cities. Paired with this is an increasing reliance on cash as the primary means of economic transaction, which has in turn stimulated the growth of micro-enterprise business activities within the township context. This article discusses the findings of an eight-township small-area census which occurred between 2010 and 2013 in Cape Town, Johannesburg, Ekurhuleni and Durban townships representing 250 000 residents. The researchers were able to establish the scope and scale of informal food and drink retailing in these localities. Of the 10 049 micro-enterprises located in the study, some 3966 (or 39% of the total) trade in food. These include enterprises in primary production, fresh produce retailing, grocery retailing from house and spaza shops, and informal foodservice enterprises. Food is the basis for much township informal business and plays an important role in making food increasingly affordable and locally accessible, and in creating cash employment. The article builds on the knowledge base of the township informal economy role in bolstering food security needs for the marginalised.  相似文献   
6.
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   
7.
Firms in emerging economies are faced with multiple, incompatible institutional forces in their environmental activities. Which of these forces will be dominant and instantiated within an organization is partly determined by the social relationships that a firm maintains with external actors. This paper investigates the relationship between board social ties and the level of environmental responsibility undertaken by firms in China, an emerging economy, by categorizing board social ties into three types in terms of the three isomorphic forces in the institutional field (coercive, normative and mimetic). Drawing on institutional and agency theories, using a sample of listed firms in environmentally sensitive industries, and a generalized least squares regression method, the results provide empirical evidence that ties that are linked to coercive and normative forces (i.e., political organizations and universities) are related to a higher level of environmental responsibility; however, those that are linked to mimetic forces (i.e., industrial peers) have a negative association with environmental responsibility, which is mitigated by CEO power. These findings suggest that the heterogeneous effects of board social ties on environmental responsibilities experienced by firms in a context of environmentalism are at an early stage.  相似文献   
8.
9.
This paper develops a tractable model of examining how factor heterogeneity and imperfect factor market interact for determining a pattern of trade. Institution plays a crucial role for the interaction. In my work, firm productivity is defined as a composition of factor productivity and technology. Thus, input selection should affect the pattern of Melitz’s intra-industry allocation due to the incurring transaction cost. For a simple model, I assume two factors (labor and capital) and two sectors, which are relatively less institution-dependent and relatively more institution-dependent. When the economy is open, effect of the transaction cost on income distribution is more drastic for an institutionally underdeveloped country. Depending on institutional quality, the economic openness reallocates resource across countries through job creation or job destruction. The job turnovers redistribute income between heterogeneous labors within countries. The income redistribution is catalyzed by international mobility of capital. As a result, income disparity is widened between the institutionally developed country and the institutionally underdeveloped country. This paper can contribute to the literature of institution and international trade.  相似文献   
10.
Against the background of supply-side structural reform and the real estate financialisation in China, this study investigates the impact of real estate holdings on R&D investment using data of enterprises listed on the Shanghai and Shenzhen stock exchanges. Our empirical results yield five main findings. First, enterprises holding more real estate assets face more serious financial constraints, thus restraining corporate innovation efficiency. Second, when the profit margin gap between entity enterprises and the real estate industry is larger, enterprises are more inclined to transfer industrial capital into the real estate industry, thus reducing R&D investment. Third, when the degree of marketisation is high, intensified market competition, the optimal allocation of factor and product markets, and stronger patent protection will weaken the restraining effect of corporate real estate holdings on R&D investment. Fourth, monopoly enterprises obtain potential profits more than undertaking risks from the real estate industry, they are more willing to hold real estate, thus strengthening the restraining effect of real estate holdings on innovation. Finally, investors' regional preference intensifies the restraining effect of corporate real estate holdings on R&D investment. Our empirical evidence can guide entity enterprises on how to effectively balance short-term (non-productive) and long-term (productive) capital investment.  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