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   478篇
  免费   12篇
  2021年   11篇
  2019年   20篇
  2018年   10篇
  2017年   10篇
  2016年   11篇
  2015年   11篇
  2014年   9篇
  2013年   95篇
  2011年   4篇
  2009年   5篇
  2008年   5篇
  2007年   5篇
  2006年   5篇
  2005年   9篇
  2004年   8篇
  2003年   6篇
  2002年   6篇
  2001年   4篇
  2000年   7篇
  1999年   4篇
  1998年   8篇
  1997年   15篇
  1996年   7篇
  1994年   10篇
  1992年   4篇
  1991年   13篇
  1990年   4篇
  1989年   7篇
  1988年   7篇
  1987年   14篇
  1986年   8篇
  1985年   6篇
  1984年   5篇
  1983年   8篇
  1982年   8篇
  1981年   5篇
  1980年   7篇
  1979年   11篇
  1978年   7篇
  1977年   8篇
  1976年   7篇
  1975年   7篇
  1974年   7篇
  1973年   12篇
  1972年   6篇
  1971年   6篇
  1970年   7篇
  1969年   6篇
  1968年   5篇
  1967年   5篇
排序方式: 共有490条查询结果,搜索用时 484 毫秒
281.
From 1956 to 1960, the French Army developed a force of Muslim auxiliaries (supplétifs) as a major component of its strategy to combat the National Liberation Front (FLN) insurgency in Algeria. Aside from their military utility in hunting down the guerrillas in the mountains and forests, the supplétifs were instrumental in undermining FLN legitimacy in the countryside. The rapid growth and employment of the supplétif force dismantled FLN political control in the villages, undermined the enemy's unity, and critically weakened the revolutionaries' claim to represent all of Algeria's Muslims. The military and political activities of France's Muslim soldiers also projected an image of Muslim–European unity behind the French cause, and portrayed the French Army as the only legitimate political force in numerous villages. These political successes, however, were limited to the local, tactical level of revolutionary warfare, and the Army was never able to convert the supplétifs into a force of decisive, strategic political significance. They thus had little ultimate impact on the outcome of the conflict.  相似文献   
282.
We examine the problem of adaptively scheduling perfect observations and preventive replacements for a multi‐state, Markovian deterioration system with silent failures such that total expected discounted cost is minimized. We model this problem as a partially observed Markov decision process and show that the structural properties of the optimal policy hold for certain non‐extreme sample paths. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
283.
We consider how a merger between two naturally differentiated dealers affects their interactions with a common supplier and identify conditions under which the merger can increase or decrease the combined net worth of the two firms. Among other things, we find that the attractiveness of merging depends upon the extent to which end demand can be stimulated by either an upstream supplier or the dealers. Specifically, the greater the supplier's ability to invest in stimulating end demand, the more likely it is that the naturally differentiated firms will be better off operating independently than merging. On the other hand, if the greatest opportunities for stimulating demand are through the service that is provided by the dealers, then merging their operations will be more attractive. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007  相似文献   
284.
For the Americans, it's no longer just “boots on the ground”: it's blood on the ground that counts.

Joel J. Sokolsky
  相似文献   
285.
Decades ago, simulation was famously characterized as a “method of last resort,” to which analysts should turn only “when all else fails.” In those intervening decades, the technologies supporting simulation—computing hardware, simulation‐modeling paradigms, simulation software, design‐and‐analysis methods—have all advanced dramatically. We offer an updated view that simulation is now a very appealing option for modeling and analysis. When applied properly, simulation can provide fully as much insight, with as much precision as desired, as can exact analytical methods that are based on more restrictive assumptions. The fundamental advantage of simulation is that it can tolerate far less restrictive modeling assumptions, leading to an underlying model that is more reflective of reality and thus more valid, leading to better decisions. Published 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 293–303, 2015  相似文献   
286.
What explains the pace at which militaries adopt new technology? We argue that the hierarchical structure and unique expertise requirements of military organizations combine to empower select individuals as ‘gatekeepers’ of innovation. These individuals acquire beliefs throughout their military careers regarding the nature and means of warfare that act to shape their attitudes towards new military innovations. By filtering, sidelining, and ignoring competing sources of advice and information, these officers actively inhibit the adoption of new, often advantageous, innovations. We develop this argument through the analysis of two cases: the delayed acquisition of breech-loading and repeating rifles by the Union Army during the American Civil War, and the failure of the US Army to adopt an adequate heavy-type tank in World War II.  相似文献   
287.
The anthrax attacks of 2001 energized research directed toward reducing health consequences from airborne contaminants by augmenting current heating ventilation and air-conditioning (HVAC) systems. Even during peacetime, interest will continue in improving HVAC components to reduce biocontaminants associated with sick building syndrome. Current HVAC design uses numerical simulation methods of ordinary differential equations to predict approximate performance. The authors show that state-space Laplace Transform calculations actually solve the underlying differential equations and yield algebraic expressions that provide new insight. To sharpen the arguments in favor of this methodology, attention is restricted to improving existing HVAC systems to increase protection from an external release of hazardous particulates. By nearly eliminating the need for dynamical simulation, the resulting methods can be applied to far more complex HVAC designs with little additional computational effort. The new methods reduce the time required for computation by three orders of magnitude. These algebraic methods also can be extended to disparate technical problems including internal particulate release, gas masks, and designing new protective buildings.  相似文献   
288.
This study examines the failures of the William J. Clinton and Barack Obama administrations to secure ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). It applies an integrated analytical framework for assessing treaty ratification that builds upon previous research in order to understand why the Clinton administration failed to achieve CTBT ratification in 1999 and why the Obama administration has so far failed to advance the treaty in the Senate. The study concludes that CTBT ratification, despite Obama administration pledges of support, remains highly unlikely. Finally, the study analyzes the common domestic political factors present in both cases and suggests areas for further research.  相似文献   
289.
In this article, we construct and analyze an original database of overseas Chinese equity oil investments (EOI) in order to assess the relative importance of economic and geopolitical factors in determining the type of countries that are most likely to receive those investments. We find that China's national oil companies (NOCs) choose to make considerable investments in certain oil rich countries while ignoring others. We develop and examine ‘economic opportunity’ and ‘geopolitical relevance’ explanations of Chinese EOI. The economic explanation assumes that Chinese oil companies operate autonomously despite the fact that they are state owned, and that they seek international experience in countries offering less competition but more risk. The geopolitical explanation suggests that Chinese equity oil investments are developed and coordinated by the central government as part of a geopolitical strategy that is designed to bypass the so-called ‘Malacca Dilemma’ and deepen security ties with oil-rich states through the conduct of oil diplomacy. We argue that Chinese EOI tends to reflect both corporate interests and government priorities, and that it generates more liabilities rather than benefits for China.  相似文献   
290.
Clausewitz laid great emphasis on the planned construction of war, but this idea has received little attention from his commentators, who generally attach far greater importance to what he said about the chaotic elements of war, in particular its interactive nature and the friction inseparable from its conduct. This article gives long-overdue recognition to planning as a dominant theme of On War. The essential point Clausewitz makes concerning interaction is not that the enemy's responses are bound to disrupt our plans, but that our plans must aim to predict and incorporate his responses. Clausewitz acknowledges that friction creates enormous difficulties for the realization of any plan, but it is precisely in respect of this challenge that he develops the concept of military genius, whose capabilities are seen above all as the executive arm of planning.  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