舰载雷达中频信号仿真设计与实现

为满足舰载传感器或武器系统论证、设计、试验、评估、训练等全生命周期的应用,对新型舰载警戒探测与跟踪雷达中频信号模拟器的系统体系和组成进行了探讨,介绍了系统的功能和技术指标,重点研究了软件无线电在雷达中频信号模拟中的应用、雷达电磁环境和目标回波仿真等一些关键技术,包括目标航迹模拟、目标回波模拟、杂波信号模拟、雷达接收天线仿真、雷达天线方向图仿真等.采用软件无线电技术和软硬件相结合的方法较逼真地实现了海战场复杂电磁环境下雷达中频信号的模拟.     

非局部弹性杆固有频率的Ritz法求解

采用Ritz法求解了非局部弹性直杆的固有频率问题。非局部弹性理论与经典弹性理论相对应,区别在于非局部理论中,一点的应力与该点以及其周围区域的应变都有关,并采用核函数来表征这种相关性。基于Eringen提出的非局部弹性模型,针对三种给定核函数,用Ritz法进行了直杆的动力学分析。并针对两种边界条件给出直杆的固有频率,与其它方法比较,该方法具有可以针对多种核函数求解,精度可控,易于编程等优点。     

液体火箭发动机无失效条件下的可靠性分析方法

针对液体火箭发动机热试车过程中可能出现的无失效情况,在对寿命分布进行分析的基础上,利用配分布曲线-最小二乘法,采用经典估计和Bayes估计作为先验分布,对液体火箭发动机无失效条件下的可靠性进行了评估,并对评估结果进行了分析。计算结果表明,采用最小二乘法结合Bayes估计,可以较好评估液体火箭发动机在无失效条件下的可靠性。     

基于气动-弹道一体化模型的飞行器外形优化设计

为提升飞行器气动外形优化设计效果,研究了新型飞行器在大空域、宽速域范围的气动适应性问题,提出一种基于气动-弹道一体化模型的外形优化设计方法.通过考虑气动和弹道的耦合作用,综合利用类型函数/形状函数转换技术、气动工程估算方法和Radau伪谱法,建立飞行器气动-弹道一体化模型.基于该模型,通过明确优化目标和约束条件,给出基...     

利用最小二乘支持向量机求解潜艇内外磁场映射模型

为提高潜艇磁隐身能力,应对潜艇固定磁场进行实时监测,提出利用最小二乘支持向量机的潜艇内外磁场映射方法。结合内外映射法和最小二乘支持向量机原理,通过交叉验证优化模型参数,建立由内到外的潜艇磁场映射模型。以潜艇外部垂向固定磁场变化量为分析对象,仿真和实验结果均与标准值吻合良好。与径向基神经网络算法相比,该方法的泛化能力和推算精度有明显提高,且更符合工程实际,对闭环消磁技术的研究具有指导意义。     

美军作战试验与鉴定发展研究

当前,军队装备试验鉴定正由性能试验向作战试验、在役考核全领域拓展。在装备试验鉴定体系全面重塑的历史背景下,为适应军队装备试验鉴定发展新变化,探索装备试验鉴定新理论,推进装备试验鉴定自主创新发展,亟需开展装备试验鉴定技术研究。美军相对较早开展了装备试验与鉴定工作,在作战试验与鉴定工作方面已形成了较完善的法规制度体系和规范的操作流程,有较成熟的理论与方法成果可供借鉴。与此同时,美军作战试验与鉴定工作也面临许多新问题。本文剖析了美军作战试验与鉴定的内涵和管理模式,研究了2018和2019年美军作战试验与鉴定的重点技术领域,并进行了对比分析,以期掌握近期美军作战试验与鉴定工作的发展变化。     

Effect of nano powder (Al2O3-CaO) addition on the mechanical properties of the polymer blend matrix composite

This work describes the preparation and study of the properties of composite nanoparticles prepared by the sol-gel method which consists of two materials (Al₂O₃-CaO), and study the effect of these nanoparticles on the mechanical behavior of a polymer blend (EP 4% + 96% UPE). The powder was evaluated by X-ray diffraction analysis, scanning electron microscopy analysis (SEM), particle size analysis, and energy dispersive X-ray analysis (EDX). The mechanical behavior of the composite material was assessed by tensile test, bending test and hardness test. The evaluation results of the composite nanoparticles showed good distribution of the chemical composition between aluminum oxide and calcium oxide, smoothness in particles' size at calcination in high and low temperatures, formation of different shapes of nanoparticles and different (kappa and gamma) phases of the Al₂O₃ particles. The results of mechanical behavior tests showed marked improvement in the mechanical properties of the resulted composite material, especially at 1.5%, compared with polymer blend material without nano powder addition. The tensile properties improved about (24 and 14.9) % and bending resistance about (23.5 and 16.8) % and hardness by (25 and 22) % when adding particles of size (63.8 and 68.6) respectively. Therefore, this reflects the efficiency of the proposed method to manufacture the nanocomposite powder and the possibility of using this powder as a strengthening material for the composite materials and using these composite materials in bio applications, especially in the fabrication of artificial limbs.     

Damage assessment of the target area of the island/reef under the attack of missile warhead

Under the background of vigorously developing facilities of island/reef in the world, the economic value and strategic significance of the island/reef have become increasingly important. Unfortunately, they may easily become the attacking target of missiles in the war time. Therefore, aiming at the damage quantification of the targets in the island/reef under the missile attacking, a macroscopic damage assessment model for the target area is proposed in this paper. The model focuses on the construction of the assessment model framework. Firstly, the analytic hierarchy process and the grey relational analysis are applied to measure the importance of each target in the region through four indicators of the target hazard, striking urgency, damage advantage and mission relevance, respectively. Secondly, based on the damage mechanism of shock wave and fragments to target, the corresponding damage model is established, and the damage grade of each target in the evaluated area is obtained according to the damage criteria and grading standard. Finally, the model obtains the overall damage grade of the target area by employing the fuzzy comprehensive evaluation method, with synthesizing the importance and the damage grade of each target. Through the verification of an example, it demonstrates the certain feasibility of the model and provides a certain basis and reference for the subsequent research.     

新一代人工智能在国防科技领域发展探讨

新一代人工智能技术已经成为当前研究的重点和热点,并逐渐成为提升国防力量、军事能力和国家竞争力的有效途径。本文在总结人工智能概念的基础上,给出了新一代人工智能的定义和发展的重要意义,从掌握未来战争主动权、支撑军工装备研制生产模式转型和保障国防科技先进性三个方面梳理了国防科技领域发展新一代人工智能的必要性,并从基础技术支撑和国防特色应用两个方向提出了国防科技领域发展新一代人工智能涉及的基础软硬件、标准规范、智能装备/系统、辅助作战指挥、智能研发等重点内容,在此基础上给出了相关的发展建议。以上研究可为新一代人工智能技术在国防科技领域的研究、应用和发展提供参考。     

【将军论坛】科技创新思维的哲学基础、本质特征与实践要求分析

科学技术是核心战斗力,科技创新思维是开启科技创新的“金钥匙”。为实现科技兴军目标,必须高度重视对科技创新思维的研究。本文首先提出马克思主义哲学是指导科技创新思维的锐利思想武器,并从唯物论、辨证法及认识论三个方面进行了论证;其次提出科技创新思维的三个本质特征,即新颖性、全维度和多样性;最后从五个方面提出科技创新思维的实践要求,即深刻认识创新对象、紧贴创新目标要求、重视创新实践探索、建构积淀创新知识、忠于坚守创新追求。