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   2101篇
  免费   365篇
  国内免费   141篇
  2024年   4篇
  2023年   17篇
  2022年   25篇
  2021年   31篇
  2020年   40篇
  2019年   36篇
  2018年   27篇
  2017年   88篇
  2016年   103篇
  2015年   45篇
  2014年   169篇
  2013年   152篇
  2012年   141篇
  2011年   198篇
  2010年   147篇
  2009年   189篇
  2008年   149篇
  2007年   151篇
  2006年   137篇
  2005年   140篇
  2004年   135篇
  2003年   113篇
  2002年   75篇
  2001年   58篇
  2000年   30篇
  1999年   33篇
  1998年   35篇
  1997年   28篇
  1996年   14篇
  1995年   23篇
  1994年   22篇
  1993年   11篇
  1992年   12篇
  1991年   8篇
  1990年   14篇
  1989年   7篇
排序方式: 共有2607条查询结果,搜索用时 0 毫秒
651.
针对传统导弹攻击区解算方法忽略双方态势变化等问题,提出运用深度置信网络的导弹攻击区分类模型。根据导弹命中情况与目标机动间的关系,将导弹攻击区划分为五类。通过分析影响导弹攻击结果的态势参数,构建导弹攻击结果预测模型。在实验部分,结合重构误差和测试错误率确定深度置信网络的网络结构,通过逐层提取数据法分析模型参数特征并且讨论微调数据的采样方式。使用反向传播神经网络和支持向量机进行分类有效性对比实验。实验结果表明:深度置信网络运行速度和预测准确度明显优于其他两种方法,满足实时性和准确性要求,所提方法具有良好的应用价值。  相似文献   
652.
This article argues that the nuclear nonproliferation norm (NNPN) is a social fact with a relatively independent life of its own and that it has a powerful impact on the behavior of both nuclear-weapon states (NWS) and non-nuclear-weapon states (NNWS). It challenges the application of critical constructivist research on norms to the NNPN and the idea that its legitimacy and structural power depend on contestation “all the way down.” State and non-state actors play an important role in explaining the dynamics of the NNPN, but agential constructivism runs the danger of “throwing the baby out with the bath water,” neglecting the structural impact of the NNPN on state behavior. The article examines the limitations of norm-contestation theory, arguing that some norms are more resistant to contestation than others. The NNPN is more difficult to contest than new norms (such as the Responsibility to Protect) because it is rooted in fifty years of nonproliferation nuclear diplomacy. The US-India nuclear deal is not a case of “norm change” but a violation of the NNPN. The “core” of the NNPN has not changed since the US-India nuclear deal. The conflict confronting NWS and NNWS is about the implementation of “type 2” norms (organizing principles) and “type 3” norms (standardized procedures), and not about the “hard core” of the NNPN.  相似文献   
653.
This article explores why the offensive predominates military tactical thinking. With survey results showing an offensive bias among 60 per cent of senior Swedish officers and as many as 80 per cent in the case of the army, it is clear that this is not just a problem of the past but is equally relevant today. The article asks why there is a tendency to perceive and understand offensive tactics as the preferred choice and the way to conduct battle that should be encouraged and preferred. Drawing on existing research and the findings of a pilot study, ten propositions for why the offensive bias exists are tested using a mixed-method approach. Based on the findings, the article develops a model to understand why the offensive dominates military tactical thinking. It is found that the two key constitutive factors behind the offensive bias are military culture and education. These factors most directly and profoundly influence an officer’s identity, perceptions, and thinking. Military culture and education, in turn, work as a prism for four other factors: military history, the theory and principles of war, doctrine and TTPs, and psychological factors.  相似文献   
654.
根据C 2组织结构的特点,基于复杂网络理论和网络中心战思想,将C 2组织中的各作战单元、指控节点等作为节点,它们之间的信息流动作为边,构建C 2组织的网络拓扑结构。经过仿真分析,推出其内部具有无标度性、小世界性等复杂网络特性,这对于进一步将复杂网络理论应用于C 2组织的研究提供了理论依据并具有积极的意义。  相似文献   
655.
One of the most important decisions that a firm faces in managing its supply chain is a procurement decision: selecting suitable suppliers among many potential competing sellers and reducing the purchase cost. While both auctions and bargaining have been extensively studied in the literature, the research that combines auctions and bargaining is limited. In this article, we consider a combined auction‐bargaining model in a setting where a single buyer procures an indivisible good from one of many competing sellers. The procurement model that we analyze is a sequential model consisting of the auction phase followed by the bargaining phase. In the auction phase, the sellers submit bids, and the seller with the lowest bid is selected as the winning bidder. In the bargaining phase, the buyer audits the cost of the winning seller and then negotiates with him to determine the final price. For this auction‐bargaining model, we find a symmetric equilibrium bidding strategy for the sellers in a closed form, which is simple to understand and closely related to the classical results in the auction and bargaining literature. We also show that the auction‐bargaining model generates at least as much profit to the buyer as the standard auction or sequential bargaining model. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2010  相似文献   
656.
基于云-神经网络的液体火箭发动机故障检测方法   总被引:5,自引:0,他引:5       下载免费PDF全文
根据故障检测原理,研究和实现了基于云-神经网络的液体火箭发动机故障检测方法。根据训练结果、测试结果和故障检测结果可以看出,云-神经网络用于液体火箭发动机的故障检测是可行的,经过历次试车数据验证,该方法没有误报警和漏报警。  相似文献   
657.
警卫任务的特点决定了警卫人员始终处于高度的应激状态下,相同的刺激引起的心理应激是不同的,既可引起焦虑恐惧、精神抑郁、疲倦乏力等消极的反应,也可激发出斗志昂扬、精力充沛、勇敢果断等积极的反应。这主要取决于心理承受能力的强弱。研究应激心理对警卫人员处置突发事件中的影响,对有针对性地开展心理调控和组织处突训练,提高警卫人员心理素质,使其做到临危不惧、处变不惊,从而有效处置各类突发事件,确保警卫对象在任何条件下的安全,具有十分重要的现实意义。  相似文献   
658.
近年来,全国各级公安消防部门为有效防控重特大火灾事故、确保火灾形势稳定,发起了治理火灾隐患的战役。打好战役,必须讲方法、讲韬略。《孙子兵法》是一部伟大的军事著作,共分13篇,在其中选取部分精辟的观点,试述其对加强和改进消防工作的指导作用。  相似文献   
659.
从分析农村消防工作面临的严峻现状着手,探讨新农村建设中消防工作存在问题的产生原因,以山西省晋城市为例,就做好社会主义新农村建设消防工作的工作要点以及需注意的方面提出了具体的意见和观点。  相似文献   
660.
为促进社会主义新农村建设,我国采取了"家电下乡"惠民政策,这在提高农民生活质量的同时,随着用电量的增加,农村电气火灾高发不容忽视。分析了"家电下乡"背景下农村电气火灾频发的原因,提出了加大基础设施建设、提高农电管理人员消防安全素质、加强安全用电知识宣传、明确职责等几项应对措施,确保农村电气消防安全。  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