全文获取类型
收费全文 | 482篇 |
免费 | 62篇 |
国内免费 | 21篇 |
专业分类
565篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 20篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 55篇 |
2013年 | 29篇 |
2012年 | 33篇 |
2011年 | 57篇 |
2010年 | 49篇 |
2009年 | 48篇 |
2008年 | 31篇 |
2007年 | 48篇 |
2006年 | 22篇 |
2005年 | 30篇 |
2004年 | 19篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有565条查询结果,搜索用时 0 毫秒
451.
田建 《中国人民武装警察部队学院学报》2008,24(4):39-40
依据国家有关消防技术规范,介绍世纪金花钟楼购物广场安全疏散消防整改设计,探讨避难通道、帘中对开门式防火卷帘在地下商店安全疏散方面的应用。 相似文献
452.
A mathematical formulation of an optimization model designed to select projects for inclusion in an R&D portfolio, subject to a wide variety of constraints (e.g., capital, headcount, strategic intent, etc.), is presented. The model is similar to others that have previously appeared in the literature and is in the form of a mixed integer programming (MIP) problem known as the multidimensional knapsack problem. Exact solution of such problems is generally difficult, but can be accomplished in reasonable time using specialized algorithms. The main contribution of this paper is an examination of two important issues related to formulation of project selection models such as the one presented here. If partial funding and implementation of projects is allowed, the resulting formulation is a linear programming (LP) problem which can be solved quite easily. Several plausible assumptions about how partial funding impacts project value are presented. In general, our examples suggest that the problem might best be formulated as a nonlinear programming (NLP) problem, but that there is a need for further research to determine an appropriate expression for the value of a partially funded project. In light of that gap in the current body of knowledge and for practical reasons, the LP relaxation of this model is preferred. The LP relaxation can be implemented in a spreadsheet (even for relatively large problems) and gives reasonable results when applied to a test problem based on GM's R&D project selection process. There has been much discussion in the literature on the topic of assigning a quantitative measure of value to each project. Although many alternatives are suggested, no one way is universally accepted as the preferred way. There does seem to be general agreement that all of the proposed methods are subject to considerable uncertainty. A systematic way to examine the sensitivity of project selection decisions to variations in the measure of value is developed. It is shown that the solution for the illustrative problem is reasonably robust to rather large variations in the measure of value. We cannot, however, conclude that this would be the case in general. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 18–40, 2001 相似文献
453.
数字式鉴相器的相位失真是导致产生寄生信号和额外相位噪声并使锁相环路不稳定的主要因素之一。锁相环路是通讯设备、测试仪器和雷达中的一个关键部件,因此,减少鉴相器相位失真,对于系统设计是很重要的。利用差分电路,可以有效地减小鉴相器相位失真的影响。 相似文献
454.
NetBIOS环境下屏幕图形与控制命令实时传输系统 总被引:1,自引:0,他引:1
介绍了在NetBIOS环境下,采用TSR技术对8259的定时中断服务程序进行截取和修改,以进行工作站间图形与键盘命令实时传送的系统。该系统具有便于移植、多任务性好以及实时、实用性强等特点。 相似文献
455.
456.
非致命武器在各类防暴和处突任务中发挥着重要作用,为提高非致命武器的系统安全性,给出了系统安全性的定义,明确了非致命武器系统安全性的组成,分析了非致命武器本质(固有)安全性和使用安全性的关系。在建立非致命武器系统安全性评价指标的基础上,建立了适用于非致命武器的安全管理系统模型,为非致命武器的安全管理模式提供了一种新的思路。 相似文献
457.
风险传递过程中,耦合是导致风险突变的重要原因。为提供风险耦合控制方法,给出风险耦合的形式化描述,采用风险耦合弹性系数对耦合强度进行计算;基于Arena软件对某型非致命武器设计论证阶段的进度风险和费用风险之间的耦合特性进行仿真分析,分别仿真了单指标、多指标在线性和非线性耦合情形下的系统行为,结果表明:全局性的线性耦合和高强度非线性耦合能显著改变系统行为。相关结果为风险耦合控制策略的制定提供了参考。 相似文献
458.
Hans-Georg Ehrhart 《Defense & Security Analysis》2017,33(3):263-275
Each age has its own wars and its own forms of warfare. In today’s evolving world risk society warfare has entered a new development stage. The states of the “global North” adapt their forms of intervention. They increasingly practice postmodern warfare characterized especially by the role of influencing the information space, networked approaches, the incorporation of indirect and covert actions, and the special quality of new technologies. This practice furthers an increasing grey zone between limiting and de-bounding of warfare. The phenomenon of postmodern warfare raises some tough questions and offers a rich research agenda. 相似文献
459.
The U.S. system for procuring and utilizing deceased‐donor organs for transplantation has been studied and written about in many articles. The purpose of this paper is to examine the interactions between the elements that comprise this system, and point out improvement opportunities that may be affected through operations research/management techniques. The authors demonstrate the need for developing data‐driven and analytic tools. In fact, data is used to generate hypotheses and support claims throughout the paper. The paper also points out the need to fully leverage data that is available to researchers, and to seek data that is currently not deposited in a centralized archive. 相似文献
460.
贾玲 《中国人民武装警察部队学院学报》2010,26(8):95-96
介绍了信息安全风险评估的相关概念,分析了军校网络信息安全风险评估中存在的问题,并提出了应对策略,希望能对军校开展网络信息安全风险评估工作提供参考。 相似文献