全文获取类型
| 收费全文 | 881篇 |
| 免费 | 15篇 |
| 国内免费 | 7篇 |
专业分类
| 903篇 |
出版年
| 2025年 | 7篇 |
| 2024年 | 4篇 |
| 2023年 | 15篇 |
| 2022年 | 5篇 |
| 2021年 | 18篇 |
| 2020年 | 29篇 |
| 2019年 | 24篇 |
| 2018年 | 14篇 |
| 2017年 | 30篇 |
| 2016年 | 37篇 |
| 2015年 | 23篇 |
| 2014年 | 63篇 |
| 2013年 | 59篇 |
| 2012年 | 40篇 |
| 2011年 | 41篇 |
| 2010年 | 43篇 |
| 2009年 | 55篇 |
| 2008年 | 50篇 |
| 2007年 | 34篇 |
| 2006年 | 45篇 |
| 2005年 | 36篇 |
| 2004年 | 41篇 |
| 2003年 | 25篇 |
| 2002年 | 15篇 |
| 2001年 | 17篇 |
| 2000年 | 19篇 |
| 1999年 | 18篇 |
| 1998年 | 18篇 |
| 1997年 | 10篇 |
| 1996年 | 15篇 |
| 1995年 | 4篇 |
| 1994年 | 9篇 |
| 1993年 | 15篇 |
| 1992年 | 6篇 |
| 1991年 | 7篇 |
| 1990年 | 8篇 |
| 1989年 | 2篇 |
| 1988年 | 1篇 |
| 1975年 | 1篇 |
排序方式： 共有903条查询结果，搜索用时 0 毫秒
201.
202.
通过对舰载导弹垂直发射系统中贮运发射箱内环境监控、导弹综合测试、发射过程控制、射击参数装定以及应急状态自动处理等需求分析 ,提出建立综合测控系统方案 ,并探讨了以 L ONworks总线为核心的综合测控系统基本结构、组成和功用。 相似文献
203.
204.
在简要介绍模拟试验系统及搜索雷达模拟器功能和工作原理的基础上,针对某型近程反导舰炮武器情报指挥系统,提出了包括模拟试验流程、仿真数学模型及评估方法的一套模拟试验方法,弥补了单一外场试验考核不充分的不足,达到了全面科学评价被试系统的目的。该模拟方法是外场试验的补充和完善,开拓了靶场试验的新思路。 相似文献
205.
为解决炮射悬浮式GPS干扰弹的研制与应用问题,进行了炮射悬浮式GPS干扰弹靶场试验与评估研究,提出了基于雷达、GPS接收机和计算机的靶场试验解决方案和数据处理方法,给出了基于蜂窝结构的干扰弹分布覆盖设计步骤,提出了包括功能性指标、可靠性指标和安全性指标的炮射悬浮式GPS干扰弹评估方法,定义了各评估指标的效益函数。 相似文献
206.
针对某大型降落伞回收系统主伞拉直过程中出现的抽打现象进行了分析,根据其拉直过程的特点将其划分为五个阶段,分别建立了各阶段的实体模型和约束模型,通过模型的组合建立了各阶段的多体动力学模型,将各阶段模型连接进一步组成该型号大型降落伞拉直全过程的动力学模型。仿真分析了该型号大型降落伞出现抽打现象时的伞衣位形、顶部伞衣速度、伞绳和伞衣的偏离距离以及张力的变化,总结了抽打现象形成时的一些特征数据,分析结果可为大型降落伞设计、改进、使用等提供参考。 相似文献
207.
《Small Wars & Insurgencies》2012,23(4-5):781-798
The article aims to offer a survey of the historiographical analysis of British counter-insurgency practices and campaigns since the publication of Armed Forces and Modern Counter-insurgency, edited by the author and the late John Pimlott in 1985. It is argued that the volume in question was influential at a time when there was little academic interest in counter-insurgency in Britain. Moreover, the subject generally had been little studied in Britain in the past beyond work by a handful of military writers and theorists. Arguably, the analytical framework followed in Armed Forces and Modern Counter-insurgency holds its value even after over a quarter of a century. Since the 1980s, however, it has become apparent that the subject is of increasing academic interest, not least in terms of the ongoing debate on the nature and application of the concept of ‘minimum force’ in British campaigns. 相似文献
208.
Reliability data obtained from life tests and degradation tests have been extensively used for purposes such as estimating product reliability and predicting warranty costs. When there is more than one candidate model, an important task is to discriminate between the models. In the literature, the model discrimination was often treated as a hypothesis test and a pairwise model discrimination procedure was carried out. Because the null distribution of the test statistic is unavailable in most cases, the large sample approximation and the bootstrap were frequently used to find the acceptance region of the test. Although these two methods are asymptotically accurate, their performance in terms of size and power is not satisfactory in small sample size. To enhance the small‐sample performance, we propose a new method to approximate the null distribution, which builds on the idea of generalized pivots. Conventionally, the generalized pivots were often used for interval estimation of a certain parameter or function of parameters in presence of nuisance parameters. In this study, we further extend the idea of generalized pivots to find the acceptance region of the model discrimination test. Through extensive simulations, we show that the proposed method performs better than the existing methods in discriminating between two lifetime distributions or two degradation models over a wide range of sample sizes. Two real examples are used to illustrate the proposed methods. 相似文献
209.
《防务技术》2019,15(2):179-185
In this article, parametric study of single confined fragment launch device was carried out. The configuration proposed was further studied to derive the empirical relationship for effect of fragment size, charge size, confinement thickness on fragment velocity. The simulations were carried out using ANSYS-AUTODYNE explicit solver. Fragment velocities were estimated as a function of different parametric combinations of explosive quantities, charge length to diameter ratio, fragment height to diameter ratio, confinement thickness, fragment material and fragment mass. The data was further converted to charge to metal ratio under fragment and confinement. It was observed that, increase in confinement thickness, charge quantity and decrease in fragment height increases the fragment velocity. It is also noted that, charge to metal mass ratio under fragment significantly affects the fragment velocity. At the end, an empirical relationship for fragment velocity interms of all these parameters was established. Using these relations, two velocities 1831.92 m/s and 2523.9 m/s required for NATO STANAG 4496 IM test were estimated. The design parameters for these velocities are presented. Also, the results estimated using the empirical relationship has been compared with published experimental data. Error in the predicted velocities is within the acceptable range. The empirical relationship proposed will be useful for finalization of design of the fragment launch device. 相似文献
210.