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   1819篇
  免费   373篇
  国内免费   151篇
  2024年   3篇
  2023年   13篇
  2022年   23篇
  2021年   41篇
  2020年   55篇
  2019年   32篇
  2018年   50篇
  2017年   105篇
  2016年   84篇
  2015年   67篇
  2014年   158篇
  2013年   164篇
  2012年   142篇
  2011年   169篇
  2010年   126篇
  2009年   166篇
  2008年   123篇
  2007年   114篇
  2006年   112篇
  2005年   115篇
  2004年   100篇
  2003年   68篇
  2002年   62篇
  2001年   55篇
  2000年   33篇
  1999年   25篇
  1998年   31篇
  1997年   11篇
  1996年   17篇
  1995年   19篇
  1994年   16篇
  1993年   6篇
  1992年   13篇
  1991年   11篇
  1990年   5篇
  1989年   5篇
  1988年   2篇
  1987年   1篇
  1975年   1篇
排序方式: 共有2343条查询结果,搜索用时 15 毫秒
961.
采用对舰艇运动的坐标跟踪法,应用灰色预测技术,建立舰艇的灰色预测动态模型。使火炮对舰艇的射击,具有反应速度快、命中精度好、毁伤效益高和便于计算机控制等优点。  相似文献   
962.
本文通过对地面几类目标运动特性的统计研究,利用线性预测的方法进行目标特征的提取,进而用模式识别的理论对地面目标进行自动识别,取得了良好的识别效果。  相似文献   
963.
针对火控稳瞄系统存在较大的不确定性及干扰,其特征参数,如固有频率、阻尼以及负载干扰等,将随着被控炮之间差异、载弹量、目标位置的变化及工作海况的影响而产生较大变化的特点,提出了一种PFC-PID串级透明控制策略,通过内环PID控制来提高抗干扰性,外环采用预测函数控制来获得良好的跟踪性能和强鲁棒性。针对舰载火控系统的稳定瞄准中的预测函数控制,提出了船舶运动实时预报问题,根据不同海况、不同船舶的惯导信号特性的不同特点,研究了一种基于自适应长自回归模型和径向基函数神经网络芯片ZISC78的船舶运动实时预报方法。通过对射击过程的仿真,表明基于实时预报的PFC-PID串级透明控制完全可以满足舰载火控系统战技指标,且算法简单,鲁棒性好,是一种实用的火控算法。  相似文献   
964.
绿色建筑中如何实现环保标准,保证所用设备对环境无污染,噪声小,可持续 发展等特点是当前的重要课题。主要针对燃气空调系统的设计与应用进行了探析,阐述了 燃气空调的制冷原理以及单、双效吸收式制冷等技术发展路线;论述了燃气制冷技术与传统 电制冷技术比较的优势及环保特点;结合后勤工程学院科技大楼绿色空调系统设计与选型 的工程实例,从绿色环保、能源、可持续发展、费用估算等方面进行了分析,并对该燃气空调 的实际应用效果进行了总结。  相似文献   
965.
基于支持向量机的飞机备件需求预测   总被引:13,自引:1,他引:12  
支持向量机是一种机器学习算法,在国外已广泛应用于工程实践领域。首先探讨了支持向量机回归预测模型的学习和预测机制,分析其中三个重要参数对算法的影响规律,得出一套定性的参数选择方法,然后将支持向量机引入到装备综合保障分析之中,构建了飞机备件智能预测模型,并对某型军用飞机备件需求进行了预测和分析,结果表明:基于支持向量机的备件需求预测是有效的、可行的。  相似文献   
966.
海上机动目标的运动预测模型及精度分析   总被引:4,自引:1,他引:3  
分析了海上机动目标的运动特性,针对海上机动目标在某些时间段运动具有一定的规律性,用插值外推法建立了预测其运动的数学模型。并对此模型的精度进行了分析,最后给出了实例。仿真结果表明,本模型能适用于海上机动目标不同的机动方式,算法快捷,具有较强的军事应用价值,模型的计算精度完全满足某新型号导弹的作战要求。  相似文献   
967.
The premise of most Western thinking on counterinsurgency is that success depends on establishing a perception of legitimacy among local populations. The path to legitimacy is often seen as the improvement of governance in the form of effective and efficient administration of government and public services. However, good governance is not the only basis for claims to legitimacy, especially in environments where ethnic or religious identities are politically salient. Some experience in Iraq suggests that in environments where such identities are contested, claims to legitimacy may rest primarily on the identity of who governs, rather than on how whoever governs, governs. This article outlines the intellectual foundations of existing policy and doctrine on counterinsurgency, and argues that development and analysis of counterinsurgency strategy would benefit from a greater focus on the role of ethnic and religious identity in irregular warfare.  相似文献   
968.
US military operations are increasingly conducted within urban environments and with these operations come the risk of increasing the number of civilian casualties and infrastructure damage. The use of non-lethal weaponry, such as directed-energy weapons, is one method for minimizing collateral damage. This method enables US military forces to effectively fight within urban environments through force escalation capabilities. Using a series of historical examples and future scenarios for urban warfare, this article highlights deficiencies affecting military capabilities in military urban operations, addresses the consequences of collateral damage, assesses the effectiveness of directed-energy weapons in military urban operations and encourages further funding, research and integration of non-lethal weaponry, such as directed-energy weapons, within the US military.  相似文献   
969.
Efforts at winning hearts and minds (WHAM) impact on and are affected by perceptions of legitimacy. In the Namibian war for independence (1966–1989) efforts of the South African counterinsurgent forces at winning hearts and minds focused mainly on persuading the population to cooperate in exchange for material benefits and services. The article demonstrates that this successfully contributed to a dimension of legitimacy that is conceptualized as pragmatic legitimacy. However, other dimensions of legitimacy are identified in which the South Africans were lacking, that is in moral, legal, and identity-based legitimacy. Furthermore, in areas where control was contested and where the population could not be shielded from insurgent intimidation, it is argued that the effects of coercion outweighed legitimacy altogether.  相似文献   
970.
From the late 1970s and until the end of the Cold War, the ‘High North’ constituted a central theatre for military forces. Extensive NATO preparations were made, a solid infrastructure developed in northern Norway, and frequent and large-scale exercises were carried out. These developments, from the late 1970s, were much discussed by scholars and strategists. However, the change of perception, laying the foundation for the military build-up, had actually occurred a decade earlier, in the late 1960s. This change has not yet been given its rightful attention, partly because the relevant documents have only recently become available. This essay takes the chronology of events back into the 1960s and to NATO's secret discussions between the national Ministers of Defence and Chiefs of Staff. The most significant turning-points were the Flexible Response strategy of 1967; SACLANT's concern over increased Soviet naval activity and his ‘Maritime Strategy’ studies of 1965 and 1967; NATO's awakening to the Soviet SSBN threat in 1967; and the concept of ‘External Reinforcement of the Flanks’ of 1968 – finally followed by the ‘Brosio Study’ (named after the then NATO Secretary-General) of 1969. As a consequence of these developments NATO's ‘tactical northern flank’ was set to become an independent strategic theatre.  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