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   578篇
  免费   14篇
  592篇
  2019年   12篇
  2017年   18篇
  2016年   12篇
  2015年   14篇
  2014年   16篇
  2013年   115篇
  2012年   5篇
  2011年   5篇
  2010年   8篇
  2009年   12篇
  2008年   6篇
  2007年   6篇
  2006年   9篇
  2005年   10篇
  2004年   11篇
  2003年   5篇
  2002年   10篇
  2000年   7篇
  1999年   6篇
  1998年   12篇
  1997年   6篇
  1996年   8篇
  1995年   4篇
  1994年   15篇
  1993年   14篇
  1992年   8篇
  1991年   14篇
  1990年   8篇
  1989年   14篇
  1988年   14篇
  1987年   15篇
  1986年   16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   9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592条查询结果,搜索用时 15 毫秒
91.
92.
During the Nigerian Civil War (1967–1970), France chose to support Biafra, but only on a limited scale, providing mercenaries and obsolete weaponry to Ojukwu's regime. General Charles de Gaulle's assistance to Ojukwu was conditioned by the French military drawdown after 1961, the increased power of French secret services on the continent, and the interventions in Katanga (1960–1963), Gabon (1964) and Chad (1968–1972). France supported Biafra primarily to protect its former colonies from Nigeria, stop Soviet subversion and acquire an economic foothold in the oil-rich Niger Delta. De Gaulle chose a limited strategy for two reasons. If Biafra won the war, France would be Biafra's greatest ally. If Nigeria won the war, France could extricate itself from the situation relatively easily and re-establish relations with the Nigerian government, which is what ultimately occurred.  相似文献   
93.
94.
95.
A large population of independent identical units having finite mean lifetime T is observed. From the history A(y) of cumulative arrivals and the history B(y) of cumulative removals in the interval 0 ≦ y ≦ τ one must predict at time τ the desired T . Two lifetime predictors X(τ) and Y(τ) and related simple predictors obtained from A(y) and B(y) are shown to converge to T with a rate of convergence dependent on the structure of the failure rate function of the units. This dependence is studied theoretically and numerically.  相似文献   
96.
The purpose of this article is to formulate the multi-commodity maximal flow problem into a node-arc form and to show that when decomposition is applied to this form the resulting master and subproblems become precisely those described by Ford & Fulkerson [3] using the arc-chain formulation. A generalization to the problem is then considered which can potentially speed its convergence.  相似文献   
97.
This paper presents a linear programming model of a fleet of vessels which is required to transport quantities of cargo, such as coal, iron ore, limestone, and salt from certain producing ports to specific destination ports. This model has been implemented and is currently being used both for planning purposes and as an aid in scheduling the trips to be made by each vessel.  相似文献   
98.
The reformulation‐linearization technique (RLT) is a methodology for constructing tight linear programming relaxations of mixed discrete problems. A key construct is the multiplication of “product factors” of the discrete variables with problem constraints to form polynomial restrictions, which are subsequently linearized. For special problem forms, the structure of these linearized constraints tends to suggest that certain classes may be more beneficial than others. We examine the usefulness of subsets of constraints for a family of 0–1 quadratic multidimensional knapsack programs and perform extensive computational tests on a classical special case known as the 0–1 quadratic knapsack problem. We consider RLT forms both with and without these inequalities, and their comparisons with linearizations derived from published methods. Interestingly, the computational results depend in part upon the commercial software used. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010  相似文献   
99.
Previous research on African military spending suggests the existence of civil strife as the best predictor of high levels of military spending. However, little is known about why some African nations maintain strong ‘auxiliary’ or paramilitary organizations while others do not. This study finds that the presence of civil or interstate war does not strengthen reserve or irregular forces. Civilian governments promote strong paramilitary organizations to counter any threat the regular military might pose to regime survivability as a form of clientelist politics.  相似文献   
100.
We explore the impact of strategic assessment efforts on military organizations at war. To do so, we construct a model to explore the impact of a principal’s choice among imperfect performance metrics for a military operation. In doing so, the principal must consider both the incentivizing and informational properties of the metric. We show the conditions under which uncertainty regarding the nature of the agent, as well as uncertainty regarding the operational environment, drives a metric choice that induces pathological behavior from the agent. More specifically, a poor metric choice can create an overly optimistic assessment and end up prolonging the conflict. We illustrate the model’s insights in the cases of World War II and the Vietnam War.  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