一种大热惯性可控红外假目标材料的设计

介绍了电热膜和相变材料的势设计了一种夹层结构.建立了离散化传热模型,分别从模拟真目标的非热源部位和热源部位考虑对模型进行了分析计算,显示了夹层结构在模拟热像特征和实时性上的优势.     

激光光斑尺寸对烟幕干扰效果影响的研究

激光光束照射到目标表面的光斑大小会对烟幕的干扰效果产生影响。文中通过理论推导和计算，得出目标表面光斑尺寸的大小与探测器接收到的来自目标的激光功率以及烟幕干扰效果之间的关系。     

双波段红外成像系统对空中点目标测距的方法

提出了对空中点目标进行被动测距的方法.基于红外辐射在大气中的传输规律和红外成像系统的特性,建立了目标和背景的表观对比度模型.通过对两个波段上对比度模型的分析,推导出了测距公式和距离分辨率公式.理论分析表明,只要得到大气在两个波段上的消光系数,通过测量目标在两个波段、两个时刻上的目标表观对比度,即可计算得到目标距离和目标径向速度,而距离分辨率则取决于系统的对比度探测能力及相关参数.利用所得公式计算了不同气象条件下,目标距离分辨率与目标距离之间的关系.计算结果表明,该测距方法具有工程应用价值.     

Simulation of propagation of the HPM in the low-pressure argon plasma

The propagation of the high-power microwave (HPM) with a frequency of 6 GHz in the low-pressure argon plasma was studied by the method of fluid approximation.The two-dimensional transmission model was built based on the wave equation,the electron drift-diffusion equations and the heavy species transport equations,which were solved by means of COMSOL Multiphysics software.The simulation results showed that the propagation characteristic of the HPM was closely related to the average electron density of the plasma.The attenuation of the transmitted wave increased nonlinearly with the electron density.Specifically,the growth of the attenuation slowed down as the electron density increased uniformly.In addition,the concrete transmission process of the HPM wave in the low-pressure argon plasma was given.     

斜入射到非均匀等离子体上的电磁波反射系数计算

等离子体雷达隐身理论和技术的日益成熟引起了国内外的广泛关注和高度重视。本文给出了平面电磁波斜入射到一维非均匀等离子体上时其反射系数的数值计算方法,并定量分析了金属平板表面电子密度呈抛物线分布的一维非均匀等离子体的雷达隐身效果。     

红外被动定位研究

空中目标的红外辐射在大气中传输中,大气以及大气中的气溶胶会对红外辐射产生吸收和散射,从而造成红外辐射的衰减。大气对红外辐射的衰减程度可以用消光系数来描述,波长不同,消光系数也不同。如果大气气象条件在短时间内变化很小,则可认为消光系数在这段时间内没有变化。红外探测系统可以分时探测两个或多个波段的红外辐射,通过一定的信号处理手段,实现对空中目标的被动定位。文中推导了利用消光系数对空中目标进行定位的公式,并进行了计算。     

人工释放化学物质改变电离层及应用前景研究

在电离层中释放中性气体可以实现电离层的人工变态,产生"等离子体空洞",这种变态效应会影响电磁波在空问环境的传播.首先介绍了电离层变态效应引起的通信中断、聚焦和散焦等现象,然后研究了电离层变态效应在现代军事科学技术领域的应用.     

小波图像融合的最佳参数研究

为了选择一种在复杂条件下能取得较好效果的小波图像融合方法,文中对一些小波基和小波分解层数进行了比较.使用了基于区域的图像融合规则,同时通过量度融合图像的熵和标准差,进行多传感器图像融合效果的评价,通过对四类图像的融合实验,筛选出最佳的小波基和其分解层数.实验表明bior3.9是图像融合时的最佳小波基.     

Effect of Mirror Magnetic Field on Abnormal Glow Discharge of Four-Anode Device

Abstract In the four-anode device, the mirror magnetic field affects the characteristics of charged particles motion, so that the current-voltage relations of glow discharge are changed. Firstly, the discharge device is introduced, and the distribution of mirror magnetic field generated by the loops surrounding the discharge chamber is presented. Both the discharge current-voltage characteristics and the radial distributions of electron density are measured, respectively, with/without the magnetic field. When the discharge occurs in a 99.99% helium with a pressure ranging from 100 Pa to 800 Pa without magnetic field, the voltage, sustaining a certain abnormal glow discharge current, decreases with the increase in gas pressure. With a mirror magnetic field of certain intensity, the discharge voltage increases with the current in a rate slower than that without the magnetic field. Moreover, when the magnetic field intensity increases, the discharge voltage first decreases then increases. Simultaneously, the mirror magnetic field affects the moving characteristics of charged particles, and causes a more inhomogeneous electron density.     

High-power microwave propagation properties in the argon plasma array

The argon plasma induced by the L-/C-band high-power microwave(HPM) is investigated theoretically and experimentally. Influences of the microwave power, pulse width, polarization and the plasma electron density on the protection performance of the plasma array against HPM are studied. The results show that the effect of HPM is caused by energy accumulation, with the gas breakdown emerging only after a short time. The attenuation of the wave by the plasma array with the tubes off can reach approximately 23 dB at 1.3 GHz. It can also be obtained that the protection performance of the plasma array against the TE wave is better than that against the TM one. The plasma array shows better protection performance in the L-band than in the C-band. In addition,the attenuation of 5.6 GHz HPM can reach 30 dB when the tubes are turned on in the experiment.The research shows that the plasma array has protection ability against HPM.