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   586篇
  免费   16篇
  2021年   5篇
  2019年   12篇
  2018年   5篇
  2017年   18篇
  2016年   13篇
  2015年   15篇
  2014年   16篇
  2013年   117篇
  2012年   5篇
  2011年   5篇
  2010年   8篇
  2009年   12篇
  2007年   6篇
  2006年   8篇
  2005年   10篇
  2004年   11篇
  2003年   5篇
  2002年   11篇
  2000年   7篇
  1999年   6篇
  1998年   12篇
  1997年   6篇
  1996年   8篇
  1994年   16篇
  1993年   14篇
  1992年   8篇
  1991年   14篇
  1990年   8篇
  1989年   15篇
  1988年   16篇
  1987年   15篇
  1986年   17篇
  1985年   12篇
  1984年   8篇
  1983年   7篇
  1982年   7篇
  1981年   8篇
  1980年   5篇
  1979年   8篇
  1978年   12篇
  1976年   7篇
  1975年   6篇
  1974年   8篇
  1973年   7篇
  1972年   10篇
  1971年   4篇
  1970年   9篇
  1969年   6篇
  1968年   4篇
  1967年   6篇
排序方式: 共有602条查询结果,搜索用时 0 毫秒
261.
262.
263.
This paper undertakes an empirical analysis of the economic effects of military spending on the South African economy. It estimates a neo‐classical model common in the literature at the level of the macroeconomy and at the level of the manufacturing sector. An attempt is made to improve upon the model by allowing the data to determine the dynamic structure of the model through an ARDL procedure. No significant impact of military spending is found in aggregate, but there is a significant negative impact for the manufacturing sector. This suggests that the cuts in domestic military procurement that have occurred since 1989 could lead to improved economic performance in South Africa through their impact on the manufacturing sector.  相似文献   
264.
265.
In a recent paper in this journal, Wijewerra and Webb study the connection between military spending and gross domestic product (GDP) in a group of five South Asian countries, finding a small but statistically significant positive relationship between military spending and GDP. This paper reviews their approach and proposes an alternative which tries to deal with the problems of omitted variables and variable construction. It finds, in contrast, that a higher share of military spending in GDP is associated with lower growth of GDP per capita.  相似文献   
266.
In interval scheduling, not only the processing times of the jobs but also their starting times are given. This article surveys the area of interval scheduling and presents proofs of results that have been known within the community for some time. We first review the complexity and approximability of different variants of interval scheduling problems. Next, we motivate the relevance of interval scheduling problems by providing an overview of applications that have appeared in literature. Finally, we focus on algorithmic results for two important variants of interval scheduling problems. In one variant we deal with nonidentical machines: instead of each machine being continuously available, there is a given interval for each machine in which it is available. In another variant, the machines are continuously available but they are ordered, and each job has a given “maximal” machine on which it can be processed. We investigate the complexity of these problems and describe algorithms for their solution. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
267.
Consider a repeated newsvendor problem for managing the inventory of perishable products. When the parameter of the demand distribution is unknown, it has been shown that the traditional separated estimation and optimization (SEO) approach could lead to suboptimality. To address this issue, an integrated approach called operational statistics (OS) was developed by Chu et al., Oper Res Lett 36 (2008) 110–116. In this note, we first study the properties of this approach and compare its performance with that of the traditional SEO approach. It is shown that OS is consistent and superior to SEO. The benefit of using OS is larger when the demand variability is higher. We then generalize OS to the risk‐averse case under the conditional value‐at‐risk (CVaR) criterion. To model risk from both demand sampling and future demand uncertainty, we introduce a new criterion, called the total CVaR, and find the optimal OS under this new criterion. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 206–214, 2015  相似文献   
268.
This essay provides an overview of the eras of Mexican cinema followed by an analysis of 10 Spanish-language narco cinematic representations, an overview of the eras of American cinema followed by an analysis of 10 English language narco cinematic representations, and a conclusion that compares and contrasts the Mexican and US narco war cinematic experience. Due to divergent national trajectories – Mexico is engulfed in narco violence and corruption while the United States is not – more differences than similarities exist between these national cinematic genres. Dark spirituality themes are also increasingly evident in more recent narco war films.  相似文献   
269.
This essay provides an overview of the ongoing quantitative and qualitative changes in Pakistan's nuclear arsenal and their impact on deterrence stability vis-à-vis India. Prominent among these trends is a major expansion in fissile material production that enables the manufacture of lighter and more compact warheads optimized for battlefield missions; the development of cruise missiles and shorter-range ballistic missiles possessing dual-use capabilities; and a greater emphasis in doctrinal pronouncements on the need for strike options geared to all levels of conflict. Although these trends pose problematic ramifications for the risks of unauthorized and inadvertent escalation, deterrence stability in South Asia is not as precarious as many observers fear. The challenges of fashioning a robust nuclear peace between India and Pakistan cannot be lightly dismissed, however, and policy makers would do well to undertake some reinforcing measures.  相似文献   
270.
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