全文获取类型
收费全文 | 1370篇 |
免费 | 419篇 |
国内免费 | 37篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 18篇 |
2021年 | 66篇 |
2020年 | 25篇 |
2019年 | 13篇 |
2018年 | 11篇 |
2017年 | 22篇 |
2016年 | 12篇 |
2015年 | 49篇 |
2014年 | 58篇 |
2013年 | 72篇 |
2012年 | 44篇 |
2011年 | 42篇 |
2010年 | 75篇 |
2009年 | 89篇 |
2008年 | 77篇 |
2007年 | 96篇 |
2006年 | 33篇 |
2005年 | 70篇 |
2004年 | 15篇 |
2003年 | 13篇 |
2002年 | 9篇 |
2001年 | 29篇 |
2000年 | 59篇 |
1999年 | 128篇 |
1998年 | 117篇 |
1997年 | 90篇 |
1996年 | 85篇 |
1995年 | 64篇 |
1994年 | 67篇 |
1993年 | 47篇 |
1992年 | 43篇 |
1991年 | 46篇 |
1990年 | 43篇 |
1989年 | 28篇 |
1988年 | 10篇 |
1987年 | 13篇 |
1986年 | 15篇 |
1985年 | 9篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1977年 | 1篇 |
排序方式: 共有1826条查询结果,搜索用时 15 毫秒
161.
新中国成立初期,人民解放军展开了学苏军活动。这次学苏军活动,经历了全面学习、有分析有批判地学习以及确立“以我为主”方针等三个历史阶段。通过学习、借鉴苏军经验,人民解放军技战术水平和协同作战能力有了很大提高,正规化现代化革命化建设取得显著成绩,同时也积累了许多值得借鉴的经验教训。 相似文献
162.
清朝后期,侵略者接连不断的海上入侵和边防蚕食致使中国边疆动荡不安,直接刺激着清朝后期国防思想的大变革、大发展,形成了以"师夷长技以制夷"为主体的反侵略思想,由海防战略思想、海岸和海港建设思想、海军建设思想共同支撑的海防思想和以"中外之防"的治边思想、内外兼顾的陆防思想为主要内容的边防思想.这些思想影响了一系列清朝后期的反侵略战争与军事变革,较之传统国防思想有一定的进步意义.但是,由于其本质上的被动性、不彻底性,就其理论水平而言仍存在着诸多缺失与不足. 相似文献
163.
164.
165.
In this article, the Building Evacuation Problem with Shared Information (BEPSI) is formulated as a mixed integer linear program, where the objective is to determine the set of routes along which to send evacuees (supply) from multiple locations throughout a building (sources) to the exits (sinks) such that the total time until all evacuees reach the exits is minimized. The formulation explicitly incorporates the constraints of shared information in providing online instructions to evacuees, ensuring that evacuees departing from an intermediate or source location at a mutual point in time receive common instructions. Arc travel time and capacity, as well as supply at the nodes, are permitted to vary with time and capacity is assumed to be recaptured over time. The BEPSI is shown to be NP‐hard. An exact technique based on Benders decomposition is proposed for its solution. Computational results from numerical experiments on a real‐world network representing a four‐story building are given. Results of experiments employing Benders cuts generated in solving a given problem instance as initial cuts in addressing an updated problem instance are also provided. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008 相似文献
166.
In this article, we consider a classic dynamic inventory control problem of a self‐financing retailer who periodically replenishes its stock from a supplier and sells it to the market. The replenishment decisions of the retailer are constrained by cash flow, which is updated periodically following purchasing and sales in each period. Excess demand in each period is lost when insufficient inventory is in stock. The retailer's objective is to maximize its expected terminal wealth at the end of the planning horizon. We characterize the optimal inventory control policy and present a simple algorithm for computing the optimal policies for each period. Conditions are identified under which the optimal control policies are identical across periods. We also present comparative statics results on the optimal control policy. © 2008 Wiley Periodicals, Inc. Naval Research Logistics 2008 相似文献
167.
The use of life-cycle costs in procurement is limited by the accuracy of cost estimates and assessments of availability risks under the conditions generating costs. Critical to these problems are the needs and responses of equipment to maintenance and repair. Using transition probabilities to define the relationships between serviceability and maintenance and repairs, this article develops a comprehensive decision support system for military procurement. It uses a dynamic programming model to determine the least-cost set of maintenance and repair decisions, where adjustments are included for warranty conditions, time value of money, the opportunity costs of equipment failure, and the end-of-cycle salvage values or disposal costs. The system allows users to define working and failed states, create their own rules or indicators of availability from estimates of state probabilities and establish thresholds of risk acceptability. 相似文献
168.
在任职教育中开发学员任职经验的探讨 总被引:1,自引:0,他引:1
张春 《武警工程学院学报》2010,(1):55-58
任职教育是在受训学员有着一定的任职经验基础上,提高岗位任职能力的一种短期培训。在教学实施过程中,必须注重挖掘任职经验,交流任职经验,再把经验上升为理论从而去指导部队实践。这种任职经验的开发,有利于在教学过程中按需施教,扩大师生的视野,丰富教学资源,实现理论与实践的统一,有效达成任职教育的目标。 相似文献
169.
170.
完成了辐射式雷达目标射频模拟器射频前端的设计与系统集成,该模拟器工作于L/S/X三个频段,支持连续波和脉冲工作体制,具有高精度的多目标生成能力。射频前端的插件结构设计保证了射频前端的电磁兼容性能和功能可扩展性。其测试结果均优于指标要求,并支持模拟器系统成功完成了实际雷达的目标模拟实验,验证了模拟器的系统性能。 相似文献