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   33148篇
  免费   793篇
  国内免费   5篇
财政金融   5142篇
工业经济   1935篇
计划管理   3922篇
经济学   5718篇
综合类   428篇
运输经济   185篇
旅游经济   468篇
贸易经济   4084篇
农业经济   1389篇
经济概况   3601篇
水利工程   7017篇
信息产业经济   1篇
邮电经济   56篇
  2021年   252篇
  2020年   356篇
  2019年   542篇
  2018年   767篇
  2017年   738篇
  2016年   767篇
  2015年   426篇
  2014年   732篇
  2013年   3046篇
  2012年   1105篇
  2011年   1175篇
  2010年   863篇
  2009年   952篇
  2008年   1032篇
  2007年   1047篇
  2006年   925篇
  2005年   838篇
  2004年   849篇
  2003年   598篇
  2002年   647篇
  2001年   603篇
  2000年   582篇
  1999年   582篇
  1998年   515篇
  1997年   547篇
  1996年   534篇
  1995年   476篇
  1994年   483篇
  1993年   506篇
  1992年   525篇
  1991年   519篇
  1990年   439篇
  1989年   433篇
  1988年   413篇
  1987年   409篇
  1986年   396篇
  1985年   595篇
  1984年   554篇
  1983年   514篇
  1982年   482篇
  1981年   436篇
  1980年   499篇
  1979年   439篇
  1978年   373篇
  1977年   372篇
  1976年   341篇
  1975年   361篇
  1974年   310篇
  1973年   317篇
  1972年   223篇
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
1.
Water Resources Management - The water evaluation and planning (WEAP) approach and the invasive weed optimization algorithm (IWOA) are herein employed to determine the optimal operating policies in...  相似文献   
2.
Portuguese Economic Journal - A set of RLS-type models with ARMA and ARFIMA dynamics is estimated and compared in a forecasting exercise with ARFIMA, GARCH and FIGARCH models. It is an extension of...  相似文献   
3.
Extreme weather events (EWEs) pose unprecedented threats to modern societies and represent a much‐debated issue strongly interlinked with current development policies. Small and medium‐sized enterprises (SMEs), which constitute a driving force of economic growth, employment and total value added, remain highly vulnerable to and ill prepared for such environmental perturbations. This study investigates barriers to SMEs’ resilience to EWEs in an attempt to shed light on enabling factors that can define effective organizational responses to non‐linear environmental stimuli. Relying on structural equation modeling and data gathered from 109 SMEs that recently experienced EWE impacts, we link the general concept of SMEs’ resilience barriers to EWEs with a series of elements to determine specific internal and external factors that contribute the most to EWE resilience. In particular, external barriers of institutional conditions and mechanisms of support and guidance as well as internal barriers of resources and managerial perceptions are found to be the most critical ones in determining resilience. The assessment offers essential research evidence for practitioners on SME management and sets forth linkages with current mechanisms for policy interventions towards an appropriate resilience agenda for SMEs. Copyright © 2018 John Wiley & Sons, Ltd and ERP Environment  相似文献   
4.
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   
5.
At the hydroelectric unit No. 11 of the Nizhnekamsk hydroelectric power plant, the filling wedges of a rotor were investigated by ultrasound in the free st  相似文献   
6.
7.
Power Technology and Engineering - The work done on the test site to ensure the operational safety of the powerhouse of the Zagorsk PSP-2 after its leveling is described. The controlled...  相似文献   
8.
During patent litigation, pay‐for‐delay (P4D) deals involve a payment from a patent holder of a branded drug to a generic drug manufacturer to delay entry and withdraw the patent challenge. In return for staying out of the market, the generic firm receives a payment, and/or an authorized licensed entry at a later date, but before the patent expiration. We examine why such deals are stable when there are multiple potential entrants. We combine the first‐mover advantage for the first generic with the ability of the branded manufacturer to launch an authorized generic (AG) to show when P4D deals are an equilibrium outcome. We further show that limiting a branded firm's ability to launch an AG before entry by a successful challenger will deter such deals. However, removing exclusivity period for the first generic challenger will not.  相似文献   
9.
The United Nations Watercourses Convention entered into force on 17 August 2014, following a long and complex journey that dates back to 1970 when the UN referred the matter to its legal arm, the International Law Commission. This article follows the Convention through that long and turbulent road, examines its main provisions and analyses the reasons for the delay of its entry into force. It concludes by answering the question of why entry into force of the Convention should indeed matter.  相似文献   
10.
Forward guidance can be provided as an unconditional promise, i.e. commitment to a specific low policy rate. Alternatively, the promise may include an escape clause, i.e. a condition defining the state of the economy under which the central bank would not keep such a low rate and, instead, it would revert to setting policy under discretion. The escape clause can be expressed as a threshold in terms of a specific variable. The present paper shows that, when such a threshold is expressed in terms of an endogenous variable (e.g. output, inflation), there are cases where it becomes impossible for the central bank to act in a way that is consistent with its promise. Consistency imposes limits on the policy rate that can be set since reverting immediately to the optimal discretionary rate can be incompatible with exceeding the threshold.  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