大表面复杂结构伪装遮障表面温度的简化分析方法

伪装遮障大都有复杂的表面结构,直接建模计算对计算能力要求极高。表面结构对周围流场产生扰动影响对流传热,进而影响伪装表面温度。文中通过不断调整参数得到对表面有相似影响的多孔介质,实现伪装遮障表面结构到多孔介质的简化。采用局部建模的方法,分析三种典型伪装遮障表面结构对周围流场以及其温度场的影响,进而将其简化为对应的多孔介质。结果表明:将伪装遮障表面结构类比为多孔介质,大大减少了计算量,能够模拟大表面覆盖伪装遮障之后的表面温度,评估其伪装效果。将该简化模型用于室外平房这一具体情境中,分别模拟平房不加表面伪装和外加不同伪装遮障情况下,其表面温度和表观温度在全天不同时段的变化。     

伪装遮障的光学与红外偏振成像

为了研究伪装遮障对抗偏振遥感的侦察效果,采用多波段偏振CCD相机在光学与红外波段获得伪装遮障的偏振图像,并提取其中的偏振信息.研究发现:在表面形态一定的情况下,伪装遮障散射光的偏振信息受光线入射角和表面反射率的影响较大.偏振信息对遮障的表面粗糙度和空间结构非常敏感,可以增强图像中目标与背景的对比度,提高识别准确率.伪装遮障和自然背景的散射光偏振度和偏振角信息有较大差别,因而,根据偏振信息成像可以有效地识别出图像中的伪装遮障,偏振成像在伪装目标识别方面具有重要的军事应用价值.     

红外迷彩伪装对发射率要求的数值分析

针对红外迷彩伪装涂层中发射率的取值问题建立了计算模型。推导计算了目标8~14μm的平均发射率εt对目标辐射温度TR的影响,并以4 K辐射温差作为隐身标准,计算分析了目标不同真实温度T对εt取值范围的影响以及相邻斑块发射率差值△εt与固定斑块发射率ε1、目标真实温度T的关系。所得结论对红外迷彩伪装涂层的制备具有一定的指导作用。     

卷帘式遮障对抗红外成像制导武器

分析了目标红外特征及传统红外伪装手段的缺陷.以静态红外伪装网技术为基础,结合动态伪装技术概念,提出卷帘式遮障对抗红外成像制导武器的设想.介绍卷帘式遮障的设计思想、使用和回收方法,并对其伪装效能作了理论评估.卷帘式遮障作为一种主动防护手段,可以有效降低红外成像制导武器威胁.     

热红外伪装技术的研究现状与进展

热红外伪装技术在现代战争中的重要性日益凸显。在阐述其原理的基础上,综述了热红外伪装技术的主要方式,包括热红外伪装涂料技术、热红外伪装网与遮障技术、新型热红外伪装技术。分析了热红外伪装技术的研究现状与进展。     

织物热红外伪装性能测试评价技术现状

热红外伪装织物在人体的防红外热像侦察中发挥着重要作用,织物的红外辐射特性常用红外发射率进行衡量,而伪装性能常采用热成像方法进行评价。从以上两方面,介绍了红外伪装织物的现有测试评价方法,对比阐述了量热法、反射率法测试织物红外发射率的原理及特点,以及基于热成像探测能力的阈值条件和人工判读评价织物伪装性能的特点和缺陷,指明了现有热红外伪装织物测试评价方法应改进和完善的方向。     

吸收散射型伪装遮障微波散射特性研究

借助有耗介质板模型研究了伪装遮障材料电磁参数对材料散射、透射和吸收性能的影响,初步得出了材料电磁参数可能选择的范围.采用周期结构模型和Split-Field Periodic FDTD法(基于分裂场的周期结构时域有限差分法)研究了吸收散射型伪装遮障微波散射特性,通过数值计算分析了网孔尺寸、材料电磁参数、入射波频率以及入射角度等因素对伪装遮障电磁散射特性的影响,得出了一些有参考价值的结论.     

基于伪装结构兼容设计的目标RCS仿真分析

伪装遮障是掩盖工程施工活动的有效措施,支撑骨架一般采用轻钢结构,其金属材质与外部构型,在雷达侦察下,会形成强散射暴露工程位置。本文针对伪装与结构的兼容设计,在满足结构稳定性和伪装隐蔽性的同时,通过对比同等遮障面积下不同钢柱截面的用钢量,得出优先采用方形截面柱以提高经济性的结论。同时,对大跨度遮障柱网的布局给出合理建议。随后,利用电大尺寸仿真,分类计算了多种仿形屋面结构随雷达威胁方向变化的远场RCS值,分析了多种起伏特征对结构RCS的影响规律,研究结果表明,根据地势的不同,对屋面设置特定方向的起伏能有效规避强散射的形成,可为防雷达伪装遮障的方案制定提供设计依据。     

一种烟幕遮障下的伪装目标协同识别方法

针对单源传感器在迷彩伪装识别特性下的单一性和局限性,提出了一种基于可见光-热红外图像协同识别烟幕遮障下的行人的方法。该方法首先在可见光图像中识别出烟幕遮障,在热红外图像中识别出行人目标,然后利用协同机制最终可以识别出烟幕遮障下的行人。通过本文中实验数据的分析,本文中的方法能够有效地识别出烟幕遮障下的迷彩伪装行人。而且本文中的方法在去除虚警和识别率上都有了大幅度提高。     

红外迷彩伪装涂料发射率对目标伪装效率的影响

伪装效率是衡量涂料的红外伪装效果的重要指标，它取决于涂料本身的红外发射率、特定的环境背景和气候条件等多种因素。在一种典型的南方草地背景下，随着阳光辐射和昼夜环境温度的变化，研究了不同发射率涂料样品的红外伪装效率；并对不同发射率的样品进行组合，研究比较复杂的红外迷彩伪装目标的伪装效率，在此基础上，讨论了发射率对红外迷彩伪装目标的伪装效率的影响。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.