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   189篇
  免费   11篇
  国内免费   6篇
  2024年   1篇
  2022年   1篇
  2021年   2篇
  2020年   3篇
  2019年   3篇
  2017年   8篇
  2016年   8篇
  2015年   8篇
  2014年   13篇
  2013年   18篇
  2012年   7篇
  2011年   14篇
  2010年   8篇
  2009年   15篇
  2008年   6篇
  2007年   13篇
  2006年   16篇
  2005年   13篇
  2004年   9篇
  2003年   7篇
  2002年   4篇
  2001年   5篇
  2000年   2篇
  1999年   6篇
  1998年   2篇
  1995年   1篇
  1994年   3篇
  1993年   1篇
  1992年   7篇
  1990年   2篇
排序方式: 共有206条查询结果,搜索用时 31 毫秒
181.
对弹药在长期贮存过程中其发射药剩余能量的变化情况进行了研究。首先建立了箱装弹药中发射药放热规律的数学模型 ,然后利用数值模拟的方法计算了其在贮存过程中的剩余能量 ,最后对计算结果进行了分析与讨论  相似文献   
182.
Common due date problems have been extensively discussed in the scheduling literature. Initially, these problems discussed finding a common due date for a set of jobs on a single machine. These single machine problems were later extended to finding the common due date on a set of parallel machines. This paper further extends the single machine problem to finding multiple common due dates on a single machine. For a basic and important class of penalty functions, we show that this problem is comparable to the parallel machine problem. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 293–298, 2001  相似文献   
183.
The Selection Allocation Problem (SAP) is a single period decision problem which involves selecting profit‐maximizing (or cost‐minimizing) activities from various distinct groups, and determining the volume of those activities. The activities in each group are selected subject to the availability of that group's resource, which is provided by either pooling or blending raw inputs from several potential sources. Imbedded in the decision process is the additional task of determining how much raw input is to be allocated to each group to form the resource for that group. Instances of this problem can be found in many different areas, such as in tool selection for flexible manufacturing systems, facility location, and funding for social services. Our goal in this paper is to identify and exploit special structures in the (SAP) and use those structures to develop an efficient solution procedure. © 1999 John Wiley & Sons, Inc. Naval Research Logistics 46: 707–725, 1999  相似文献   
184.
针对战时基于定点调拨的弹药储备与基于定期调拨的弹药储备中存在的断供与盲供问题,从弹药消耗及补给数据出发,围绕弹药消耗量、补给量与储备量之间的相互关系,以优化技术为手段,兼顾基于定点调拨弹药储备与基于定期调拨弹药储备的优点,通过寻求最佳弹药储备量和最佳弹药补给点的方法,实现了弹药储备量的优化控制,为今后的弹药储备控制方法研究提供了理论依据和参考。  相似文献   
185.
追击炮射击时可能会发生弹药重复装填,常常导致膛炸等严重事故,迫击炮防重装装置可有效防止该类事故发生。分析对比了光电式、电磁式、机械式3种技术方案的工作原理、技术特点,设计了一种安全可靠、能够适应各种复杂恶劣环境的机械式迫击炮防重装装置,详细介绍了其结构设计、工作原理和技术性能。  相似文献   
186.
本文从理论上详细分析了影响密封包装弹药内部湿度的可能因素,提出了密封包装弹药在长期储存过程中应该采取的防潮管理措施及对策。  相似文献   
187.
This study investigates the ricochet behaviour of three different small-arms projectile types using a novel ricochet measuring device.The results can be used to estimate the danger potential of ricochets on shooting ranges.A ricochet is the change of direction and velocity of a projectile after impacting an oblique surface.This impact produces strong vibrations on a rigid plate.During this impact,flexural waves travel radially outwards from the point of impact.These waves are used to determine the properties of the impactor with accelerometers situated on the target surface.With the use of two measurement plates,one can produce a ricochet and detect the velocity at the same time.Accelerometers are suitable for accurate momentum measurements of single impacts.However,depending upon strike velocity and the impact angle,a ricochet can separate in multiple fragments after being deflected.From the operational safety perspective,these fragments need to be detected,as well.The approach of a coupled sensor concept was chosen to solve this problem.Thermographic sensors were additionally used to visualise the heat which is produced after pene-trating a rubber layer pasted in front of the steel target plate.With this approach one was able to detect the position of impact.The investigations showed that the measurement system performance is better with a multiple sensor design,which includes accelerometers for the velocity,impact strength and partly the position measurement,while the thermographic sensor was used for the position measurement and partly the momentum measurement.The investigated ammunition showed plausible fragmentation behaviour,and the results can already be used to estimate the danger potential of different ammunition types.Frangible projectiles fragment to small particles already after being deflected under a small angle.However,Full Metal Jacket projectiles with or without a steel core do not fragment under angles which are less than 5°.The objective of the paper is to demonstrate the possibility of measuring the complex ricochet me-chanics of small projectiles using standard accelerometers with the adequate signal processing approach.This measuring system is supported by an off the shelf thermographic camera.  相似文献   
188.
Safety of underground ammunition storage is an important issue, especially during the accidental ignition of missiles. This work investigates the pressure and temperature distribution of the multi-layer underground ammunition storage with a pressure relief duct during the accidental ignition process of the missile. A large-scale experiment was carried out using a multi-layered restricted space with a pressure relief duct to simulate the underground ammunition store and a solid rocket motor to simulate the accidental ignition of the missile. The results show that when the motor gas mass flow increased by 5.6 times, the maximum pressure of the ammunition storage increased by 5.87 times. At a certain motor flow rate, when the pressure relief exhaust area at the end of the relief duct was reduced by 1/2, the maximum pressure on the first layer did not change. But the rate of pressure relief was reduced and the time delayed for the pressure of ammunition store to drop to zero. In this experiment, when the motor ignition position was located in to the third layer ammunition chamber, the maximum pressure was reduced by 32.9% and also reduced the rate of change of pressure. In addition, for the experimental conditions, the theoretical analysis of the pressure relief of the ammunition storage is given by a simplified model. Based on the findings, some suggestions to the safety protection design of ammunition store are proposed.  相似文献   
189.
We study the problem of recovering a production plan after a disruption, where the disruption may be caused by incidents such as power failure, market change, machine breakdown, supply shortage, worker no‐show, and others. The new recovery plan we seek after has to not only suit the changed environment brought about by the disruption, but also be close to the initial plan so as not to cause too much customer unsatisfaction or inconvenience for current‐stage and downstream operations. For the general‐cost case, we propose a dynamic programming method for the problem. For the convex‐cost case, a general problem which involves both cost and demand disruptions can be solved by considering the cost disruption first and then the demand disruption. We find that a pure demand disruption is easy to handle; and for a pure cost disruption, we propose a greedy method which is provably efficient. Our computational studies also reveal insights that will be helpful to managing disruptions in production planning. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005.  相似文献   
190.
We focus on the concave‐cost version of a production planning problem where a manufacturer can meet demand by either producing new items or by remanufacturing used items. Unprocessed used items are disposed. We show the NP‐hardness of the problem even when all the costs are stationary. Utilizing the special structure of the extreme‐point optimal solutions for the minimum concave‐cost problem with a network flow type feasible region, we develop a polynomial‐time heuristic for the problem. Our computational study indicates that the heuristic is a very efficient way to solve the problem as far as solution speed and quality are concerned. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005  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