全文获取类型
收费全文 | 189篇 |
免费 | 11篇 |
国内免费 | 6篇 |
专业分类
206篇 |
出版年
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 15 毫秒
81.
针对弹药装填机器人取弹后自身质量改变较大,运转时会受到质量变化和复杂车内环境共同作用,容易产生运动位移误差现象,采用一种基于重力改进的自适应PD控制算法,实现了弹药装填机器人实际运动轨迹与预定轨迹的快速跟踪要求,并通过Matlab-Simulink进行了仿真验证,得到了较好的控制效果。 相似文献
82.
83.
We study a problem of scheduling products on the same facility, which is motivated by a car paint shop. Items of the same product are identical. Operations on the items are performed sequentially in batches, where each batch is a set of operations on the same product. Some of the produced items are of the required good quality and some items can be defective. Defectiveness of an item is determined by a given simulated function of its product, its preceding product, and the position of its operation in the batch. Defective items are kept in a buffer of a limited capacity, and they are then remanufactured at the same facility. A minimum waiting time exists for any defective item before its remanufacturing can commence. Each product has a sequence independent setup time which precedes its first operation or its operation following an operation of another product. A due date is given for each product such that all items of the same product have the same due date and the objective is to find a schedule which minimizes maximum lateness of product completion times with respect to their due dates. The problem is proved NP‐hard in the strong sense, and a heuristic Group Technology (GT) solution approach is suggested and analyzed. The results justify application of the GT approach to scheduling real car paint shops with buffered rework. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 458–471, 2014 相似文献
84.
建立了带壳体云爆弹药数值模拟模型,分析了圆柱壳体的断裂准则。壳体材料采用Johnson-Cook热粘性本构方程,断裂准则采用Taylor断裂应力准则,应用Autodyn软件进行了数值模拟,给出了内部爆炸载荷下液体燃料的压力曲线和速度曲线,并进行了分析。 相似文献
85.
针对初始库存和终止库存不为零的生产与库存问题,通过适当设置需求量,将其化为初始库存和终止库存为零的问题,以便应用重生性质进行求解。 相似文献
86.
André Roux 《Defence and Peace Economics》2013,24(1):149-172
This article examines the relationship between defence expenditure and economic performance in South Africa, both prior to and after that country's first fully democratic election in 1994. Prior to 1994 defence expenditure decisions were largely dominated by non‐economic factors; since then defence spending has declined in reaction to, inter alia, the need to address a number of socio‐economic inequities. After 1975 in particular, military industrialisation in South Africa placed a disproportionately high burden on the country's industrial resources and natural economic and technical capabilities. However, although this suggests that the opportunity cost of domestic arms production has been fairly high, the country's poor economic and development performance since the mid‐1970s is a function of underlying structural deficiencies and institutional constraints rather than the consequence of inordinately high defence spending levels. 相似文献
87.
Jurgen Brauer 《Defence and Peace Economics》2013,24(3):461-480
In this paper I develop indices and rankings of potential and actual arms production for about one hundred and fifty countries for data pertaining to the early to mid‐1990s. The countries’ ranked indices are then compared. I find evidence that countries that can produce arms (potential) do produce arms (actual). I also compare the current findings to findings published nine years ago, pertaining to potential and actual arms production in developing nations for the early 1980s. A number of countries then having the potential to produce arms have, in fact, become major arms producers ten years later. The results presented in this paper carry policy implications for the arms trade debate: shall policymakers continue to focus on arms supply restriction and continue to ignore the increasing capacity of developing nations to self‐supply their arms demand? 相似文献
88.
The 1977 UN arms embargo was one of the main factors which led South Africa to establish a largely self sufficient import‐substituting arms industry capable of meeting the apartheid state's demand for sophisticated weaponry. While macroeconomic studies suggest that high military spending had a damaging effect on economic growth, no studies have investigated the disaggregated impact of military expenditure on industrial development. This paper applies panel data methods to the Industrial Development Corporation's Sectoral Database in order to analyse the level effects of military spending. 相似文献
89.
In 1796 a 13-year-old boy playing on wasteland behind his father’s house in Ribchester, Lancashire discovered an assemblage of over 30 Roman artefacts, including a decorated brass helmet. Although partially corroded the Ribchester helmet is a fine example of a first-century AD cavalry sports helmet. This article considers how the interpretation of the helmet has evolved since its discovery. The multi-faceted iconography of the helmet with its mural crown diadem is that of an elite soldier and is paralleled in other examples of cavalry sports helmets of the Ribchester type. The long-neglected imagery on the helmet bowl is reinterpreted and seen not as a haphazard collection of randomly placed combatants but as a highly structured, symmetrical composition specifically designed to be viewed from different directions. 相似文献
90.
台湾通过军购、仿制与自主研制 3种模式发展导弹武器,已拼凑起庞杂的导弹武器装备,并随着装备战略的变化,正在重点发展中远程精确打击能力。 相似文献