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   5716篇
  免费   90篇
财政金融   1234篇
工业经济   440篇
计划管理   914篇
经济学   1194篇
综合类   91篇
运输经济   42篇
旅游经济   110篇
贸易经济   985篇
农业经济   260篇
经济概况   534篇
邮电经济   2篇
  2023年   27篇
  2021年   42篇
  2020年   92篇
  2019年   101篇
  2018年   117篇
  2017年   124篇
  2016年   124篇
  2015年   90篇
  2014年   122篇
  2013年   682篇
  2012年   149篇
  2011年   202篇
  2010年   167篇
  2009年   199篇
  2008年   176篇
  2007年   171篇
  2006年   129篇
  2005年   142篇
  2004年   124篇
  2003年   148篇
  2002年   136篇
  2001年   109篇
  2000年   127篇
  1999年   126篇
  1998年   137篇
  1997年   118篇
  1996年   98篇
  1995年   111篇
  1994年   90篇
  1993年   80篇
  1992年   67篇
  1991年   83篇
  1990年   74篇
  1989年   58篇
  1988年   60篇
  1987年   56篇
  1986年   65篇
  1985年   97篇
  1984年   98篇
  1983年   92篇
  1982年   78篇
  1981年   73篇
  1980年   72篇
  1979年   67篇
  1978年   75篇
  1977年   68篇
  1976年   68篇
  1975年   60篇
  1974年   57篇
  1973年   39篇
排序方式: 共有5806条查询结果,搜索用时 31 毫秒
11.
12.
13.
A trade restrictiveness index (TRI) aggregates an entire protection structure into a single uniform measure that is consistent with trade theory and reflects the extent of policy interventions on trade or welfare. Although there are several variants of a TRI, all approaches aggregate protective measures using weights that depend on import demand and export supply elasticities; some studies ignore cross-price effects while others account for them. This study measures the degree of bias introduced by ignoring cross effects. It provides a practical approach to account for demand- and supply-side cross-price effects in a multi-commodity TRI setting. This approach is illustrated with a case study of distortions in the Canadian crop and livestock sector. Domestic demand and supply cross effects are approximated using a “constant differences of elasticities of substitution” functional form. On average, over the period 1996–2016, we find that cross-price effects do make a difference, and that including them makes the TRI 27% higher than an approach which ignores them. Furthermore, both TRI approaches produce indices that are higher and more variable than the OECD's percentage Producer Support Estimate (PSE) that measures policy transfers as a share of gross farm receipts. The fundamental differences between a TRI and PSE% is driven by market price support for milk.  相似文献   
14.
15.
16.
17.
Labor arbitration helps define employee and employer rights and responsibilities. Evidence indicates that the advocates at arbitration tend to concern themselves with issues unrelated to the facts of the case or to the rights and responsibilities of the parties involved. More specifically, before the hearing, management and union advocates often dwell on issues such as the importance of the arbitrators’ personal characteristics and their decision-making history, the likely effects of the gender of arbitrators and grievants, and whether the presence of legal counsel impacts the arbitral outcomes. The purpose of this study is to examine whether these non-case-related factors actually can be associated with differing awards by arbitrators. This study may be the first in which the arbitrators’ decision-making history (award orientation) is a primary issue. Of all the issues studied, the arbitrator’s disciplinary award orientation is the only one with a consistent impact on arbitral outcomes. We conclude that the energy and resources expended by the advocates concerning non-case-related issues would be better spent in preparing their cases for arbitration and in examining the potential impact of arbitration on the rights and responsibilities of management and its employees.  相似文献   
18.
We use a least squares metric to match the return pattern of a target stock with that of an out‐of‐sample‐twin. The twin with the smallest metric is found by a comprehensive period‐by‐period search of stocks in the Center for Research in Security Prices data set extending back to 1926. If technical analysis has value, targets of twins producing the highest returns in the twin postperiod should also have the highest performance in the target postperiod. Using a randomly selected sample of 66,000 return patterns, we find higher means for targets corresponding to the highest returning twin quintile. We also use regressions to risk adjust target returns and find that twin returns in the postmatch period significantly predict risk‐adjusted target returns.  相似文献   
19.
Allocating resources to competing large‐scale infrastructure projects involves multiple objectives. Traditional decision‐aiding methodologies focus on the trade‐offs among performance and resource objectives. Existing methodologies may fail to account for unknown and emergent risks that are typical of large‐scale infrastructure investment allocation problems. In modern portfolio theory, it is well known that a diversified portfolio can be very effective to reduce non‐systematic risks. The approach of diversification is equally important in choosing robust portfolios of infrastructure projects that may be subject to emergent and unknown risks. In this paper, we demonstrate a methodology to analyze and compare the diversification of portfolios of large‐scale infrastructure projects. We classify and explore several metrics of diversification and integrate them with risk and other performance objectives in a multiobjective approach. We test the new metrics and the methodology in a case study of hundreds of millions of dollars of infrastructure investments. The results suggest that the solutions that consider diversification are more robust to emergent risks, thus, identifying an opportunity to incorporate diversification‐based optimization methodologies to support a variety of problems involving large‐scale infrastructure investments.  相似文献   
20.
This paper illustrates the development of an object-oriented Bayesian network (OOBN) to integrate the safety risks contributing to an in-flight loss-of-control aviation accident. With the creation of a probabilistic model, inferences about changes to the states of the accident shaping or causal factors can be drawn quantitatively. These predictive safety inferences derive from qualitative reasoning to conclusions based on data, assumptions, and/or premises, and enable an analyst to identify the most prominent causal factors leading to a risk factor prioritization. Such an approach facilitates a mitigation portfolio study and assessment. The model also facilitates the computation of sensitivity values based on perturbations to the estimates in the conditional probability tables. Such computations lead to identifying the most sensitive causal factors with respect to an accident probability. This approach may lead to vulnerability discovery of emerging causal factors for which mitigations do not yet exist that then informs possible future R&D efforts. To illustrate the benefits of an OOBN in a large and complex aviation accident model, the in-flight loss-of-control accident framework model is presented.  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