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   2127篇
  免费   64篇
财政金融   437篇
工业经济   160篇
计划管理   386篇
经济学   471篇
综合类   18篇
运输经济   18篇
旅游经济   36篇
贸易经济   390篇
农业经济   68篇
经济概况   182篇
邮电经济   25篇
  2023年   13篇
  2021年   19篇
  2020年   36篇
  2019年   47篇
  2018年   53篇
  2017年   59篇
  2016年   63篇
  2015年   30篇
  2014年   70篇
  2013年   231篇
  2012年   98篇
  2011年   75篇
  2010年   85篇
  2009年   106篇
  2008年   84篇
  2007年   78篇
  2006年   78篇
  2005年   59篇
  2004年   60篇
  2003年   57篇
  2002年   59篇
  2001年   50篇
  2000年   44篇
  1999年   37篇
  1998年   37篇
  1997年   34篇
  1996年   29篇
  1995年   25篇
  1994年   15篇
  1993年   27篇
  1992年   28篇
  1991年   31篇
  1990年   20篇
  1989年   20篇
  1988年   16篇
  1987年   13篇
  1986年   9篇
  1985年   25篇
  1984年   27篇
  1983年   18篇
  1982年   19篇
  1981年   27篇
  1980年   17篇
  1979年   17篇
  1978年   14篇
  1977年   22篇
  1976年   17篇
  1975年   10篇
  1974年   10篇
  1973年   11篇
排序方式: 共有2191条查询结果,搜索用时 15 毫秒
71.
This paper is concerned with the problem of how to place hazardous material cars in the train assembly process so that the overall derailment risk can be minimized. The approach considers both the probability of railway cars derailing en route by position as well as the risk associated with additional operations in the rail yard using recent US FRA data. The merits of this car placement model are illustrated through a case study of a railway corridor that connects Los Angeles (CA) to Chicago (IL). The case study demonstrates that the proposed risk minimization strategy could be implemented with minimal rail yard operation cost.  相似文献   
72.
Chronic eosinophilic pneumonia is one form of eosinophilic lung disease that includes both idiopathic and known etiological cases. Chronic eosinophilic pneumonia has a characteristic clinical picture, along with a characteristic pattern on CT imaging. It is readily treatable with oral steroids, and although response is prompt with excellent resolution of the symptoms, chronic steroids are often necessary. The mortality from this disease is negligible.  相似文献   
73.
Investors have always been interested in reducing inflation risk in their portfolios. However, investors face different types of inflation than those measured by the Consumer Price Index (CPI). Moreover, different asset classes can be used to hedge portfolio inflation. In this paper, we show how individual equities can be used to construct equity portfolios sensitive to customized inflation targets. We illustrate portfolios for three types of inflation: US headline CPI, Forbes Cost of Living Extremely Well Index, and the US Medical Care Price Index. We also show how alternative weighting schemes, such as minimum volatility and maximum inflation beta, can be used to construct inflation‐hedged portfolios.  相似文献   
74.
Errors introduced by using aggregate data in estimating a consumer demand model have long been a concern. We study the effects of such errors on elasticity estimates derived from AIDS and QUAIDS models. Based on a survey of published articles, a generic parameterization of the income distribution, and the range of Gini coefficients reported for 28 OECD countries, we generate and analyze a large number of “observations” on the differences between elasticities calculated at the aggregate level and those calculated at the micro level. We suggest a procedure for evaluating the likely range of aggregation error when a model is estimated with aggregate data.  相似文献   
75.
Murphy J 《Nursing economic$》2011,29(6):339-341
National Health IT Week, which ran from September 11-16, 2011, served as a time to highlight the importance of efficient information systems that protect the privacy and security of personal health information while improving the delivery of health care in the United States. During the week, the health IT community came together to raise national awareness regarding the consistent breakthroughs and hard work industry professionals, providers, and consumers have put forward to ensure they are moving toward the common goal of advancing the future of health care through private and secure health IT. Two events during the week (the Consumer Health IT Summit and the launch of the HealthlT.gov web site) brought home a theme increasingly seen as important to improving our health care system--patients participation in their care. Nurses will need to work with patients so they understand the importance of their participation as a partner in their care, instead of playing a passive role. One way we can do that is to encourage our patients to actively use technology to manage their own health care and to share information with their health care providers.  相似文献   
76.
Murphy J 《Nursing economic$》2011,29(3):150-153
Nursing informatics has evolved into an integral part of health care delivery and a differentiating factor in the selection, implementation, and evaluation of health IT that supports safe, high-quality, patient-centric care. New nursing informatics workforce data reveal changing dynamics in clinical experience, job responsibilities, applications, barriers to success, information, and compensation and benefits. In addition to the more traditional informatics nurse role, a new position has begun to emerge in the health care C-suite with the introduction of the chief nursing informatics officer (CNIO). The CNIO is the senior informatics nurse guiding the implementation and optimization of HIT systems for an organization. With their fused clinical and informatics background, informatics nurses and CNIOs are uniquely positioned to help with "meaningful use" initiatives which are so important to changing the face of health care in the United States.  相似文献   
77.
Along with concerns over the effectiveness of earth system governance, ways of enhancing its accountability and legitimacy are increasingly coming to the fore in both scholarly debate and political practice. Concerns over accountability and legitimacy pertain to all levels of governance, from the local to the global, and cover the spectrum of public and private governance arrangements. This conceptual article elaborates on the sources, mechanisms and reform options relating to more accountable, legitimate and democratic earth system governance. We proceed in four steps. First, we conceptualize accountability and legitimacy in earth system governance. Second, we place questions of accountability and legitimacy within the larger context of earth system transformation, which, we argue, poses special challenges to the pursuit of accountability and legitimacy. Third, drawing on the contributions to this special section, we analyze different sources and mechanisms of accountability and legitimacy and their effects on the democratic potential and effectiveness of governance. Fourth, in concluding, we outline reform options that may help alleviate persisting deficits in the democratic potential of earth system governance.  相似文献   
78.
We study a general equilibrium model of asset trading with financial leverage, where the investors can engage in speculative trading with diverse beliefs about the asset??s fundamental value. We show that an increase in the leverage ratio causes the stock price to rise in the current period through a ??leverage effect??, and will result in more borrowing and more stock purchase that pumps the stock price higher in the subsequent period, known as the ??pyramiding effect??. There can also be a ??depyramiding effect?? when the price falls because lenders issue margin calls and force stock sales, contributing to further stock price plummeting. Price changes from depyramiding effect, however, may not take effect when margin calls are not triggered. We demonstrate that, under certain conditions, decreasing leverage ratios leads to lower stock price volatility, measured by the variation of prices caused by an exogenous shock, when the shock is unanticipated. The influences of dispersion of beliefs and available investment funds on the relation between financial leverage and market volatility are also examined. When the shock is anticipated, we demonstrate that reducing leverage ratios may not lower stock price volatility, which poses an important challenge to future studies on this issue.  相似文献   
79.
80.
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