全文获取类型
| 收费全文 | 402篇 |
| 免费 | 0篇 |
专业分类
| 402篇 |
出版年
| 2021年 | 4篇 |
| 2020年 | 4篇 |
| 2019年 | 6篇 |
| 2018年 | 3篇 |
| 2017年 | 8篇 |
| 2016年 | 7篇 |
| 2015年 | 8篇 |
| 2014年 | 6篇 |
| 2013年 | 64篇 |
| 2011年 | 4篇 |
| 2009年 | 4篇 |
| 2007年 | 6篇 |
| 2005年 | 4篇 |
| 2004年 | 7篇 |
| 2003年 | 4篇 |
| 2002年 | 6篇 |
| 2001年 | 7篇 |
| 2000年 | 4篇 |
| 1999年 | 7篇 |
| 1998年 | 9篇 |
| 1997年 | 9篇 |
| 1996年 | 6篇 |
| 1995年 | 11篇 |
| 1994年 | 12篇 |
| 1993年 | 10篇 |
| 1992年 | 11篇 |
| 1991年 | 11篇 |
| 1990年 | 6篇 |
| 1989年 | 4篇 |
| 1988年 | 8篇 |
| 1987年 | 8篇 |
| 1985年 | 8篇 |
| 1984年 | 9篇 |
| 1983年 | 6篇 |
| 1982年 | 5篇 |
| 1981年 | 9篇 |
| 1980年 | 6篇 |
| 1979年 | 11篇 |
| 1978年 | 6篇 |
| 1977年 | 5篇 |
| 1976年 | 6篇 |
| 1975年 | 8篇 |
| 1974年 | 7篇 |
| 1973年 | 6篇 |
| 1972年 | 8篇 |
| 1971年 | 6篇 |
| 1970年 | 3篇 |
| 1969年 | 3篇 |
| 1968年 | 5篇 |
| 1967年 | 4篇 |
排序方式： 共有402条查询结果，搜索用时 15 毫秒
301.
302.
针对低雷诺数壁面约束流动中皮托管测速误差产生的两大主要影响因素——剪切速度与近壁效应,采用计算流体力学技术分别对其进行数值模拟,并研究各自引起的误差变化规律。数值模拟结果表明:虽然剪切速度引起的流线偏移规律与相关文献结论基本一致,但是数值结果预测的流线偏移量并不是一个渐近函数;近壁距离在5倍管径即出现较为明显的测量误差,并且发现近壁距离在1倍管径处出现误差的非单调性变化。最后通过将数值模拟结果与现有的修正方法进行对比,提出了更为合理的修正方程。 相似文献
303.
C. J. Ancker 《海军后勤学研究》1976,23(4):703-711
In this analysis we extend the theory of stochastic duels to include the situation where one of the contestants fires a single infinitely long burst at a fixed rate of fire and secondly where he fires fixed-length, fixed-rate of fire bursts randomly spaced. In both cases the opponent fires single rounds randomly spaced. Special cases and parameter effects are considered. 相似文献
304.
Chelsea C. White 《海军后勤学研究》1979,26(3):415-422
This paper characterizes the structure of optimal strategies for a replacement problem for two special cases of observation quality. It is shown that when the state of the system is either completely observed or completely unobserved at every decision epoch by the controller, reasonable assumptions are sufficient for the existence of optimal replacement strategies composed of policies having a generalized, control-limit form. These structural results are of particular interest since the optimal cost functions for the two special cases represent bounds on the optimal cost function for the general partially observed case, significant computational simplification can result for the two special cases due to their optimal strategy structure, and optimal strategies possessing a control-limit structure do not necessarily exist for the general partially observed case. 相似文献
305.
Brent C. Bankus 《Small Wars & Insurgencies》2013,24(1):137-143
Today there are many calls for other elements of the government to do more to ‘do their part’, assist the military to restore order and stability and ‘win the peace’ in Iraq and Afghanistan, and prepare for similar roles in future conflicts. The authors here instead briefly review the history of US armed forces’ involvement in military governance operations from the Mexican War through World War II, and recommend the re-establishment of a School of Military Government similar to that created during the latter conflict. 相似文献
306.
We consider the single machine parallel batch scheduling problems to minimize makespan and total completion time, respectively, under precedence relations. The complexities of these two problems are reported as open in the literature. In this paper, we settle these open questions by showing that both problems are strongly NP‐hard, even when the precedence relations are chains. When the processing times of jobs are directly agreeable or inversely agreeable with the precedence relations, there is an O(n2) time algorithm to minimize the makespan. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004 相似文献
307.
Consider a renewal process whose interrenewal-time distribution is phase type with representation (α, T). We show that the (time-dependent) excess-life distribution is phase type with representation (α′, T), where α′ is an appropriately modified initial probability vector. Using this result, we derive the (time-dependent) distributions for the current life and the total life of the phase-type renewal process. They in turn enable us to obtain the equilibrium distributions for the three random variables. These results simplify the computation of the respective distribution functions and consequently enhance the potential use of renewal theory in stochastic modeling—particularly in inventory, queueing, and reliability applications. © 1992 John Wiley & Sons, Inc. 相似文献
308.
The aim of this article is to evaluate how French Major Conventional Weapons (MCW) exports impact on the conflict intensity of recipient countries. The recent increase in French arms exports seems to contradict the French political discourse on the promotion of regional stability. We run zero-inflated ordered probit model in order to analyze the role of the arms trade on the intensity of civil conflicts in 144 countries from 1992 to 2014, using SIPRI and UCDP/PRIO data. Our results suggest that French MCW exports tended not to exacerbate intrastate conflicts during this period. This finding is robust to changes in the empirical framework. We propose two lines of explanations: France seems to be prone to choosing partners that respect human rights and selling more ‘defense-oriented’ MCW than the rest of the world. 相似文献
309.
David R. Morrison Jason J. Sauppe Wenda Zhang Sheldon H. Jacobson Edward C. Sewell 《海军后勤学研究》2017,64(1):64-82
The cyclic best‐first search (CBFS) strategy is a recent search strategy that has been successfully applied to branch‐and‐bound algorithms in a number of different settings. CBFS is a modification of best‐first search (BFS) that places search tree subproblems into contours which are collections of subproblems grouped in some way, and repeatedly cycles through all non‐empty contours, selecting one subproblem to explore from each. In this article, the theoretical properties of CBFS are analyzed for the first time. CBFS is proved to be a generalization of all other search strategies by using a contour definition that explores the same sequence of subproblems as any other search strategy. Further, a bound is proved between the number of subproblems explored by BFS and the number of children generated by CBFS, given a fixed branching strategy and set of pruning rules. Finally, a discussion of heuristic contour‐labeling functions is provided, and proof‐of‐concept computational results for mixed‐integer programming problems from the MIPLIB 2010 database are shown. © 2017 Wiley Periodicals, Inc. Naval Research Logistics, 64: 64–82, 2017 相似文献
310.
We study joint preventive maintenance (PM) and production policies for an unreliable production‐inventory system in which maintenance/repair times are non‐negligible and stochastic. A joint policy decides (a) whether or not to perform PM and (b) if PM is not performed, then how much to produce. We consider a discrete‐time system, formulating the problem as a Markov decision process (MDP) model. The focus of the work is on the structural properties of optimal joint policies, given the system state comprised of the system's age and the inventory level. Although our analysis indicates that the structure of optimal joint policies is very complex in general, we are able to characterize several properties regarding PM and production, including optimal production/maintenance actions under backlogging and high inventory levels, and conditions under which the PM portion of the joint policy has a control‐limit structure. In further special cases, such as when PM set‐up costs are negligible compared to PM times, we are able to establish some additional structural properties. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献