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提出了一种实时调整红外相机积分时间的方法。针对成像为点目标且灰度值变化剧烈的情况,为保证红外辐射特性测量的精度,标定了相机在不同积分时间下亮度与成像灰度值的对应关系,确定了红外相机响应关系线性度较好的区域;提出了点目标弥散范围的计算方法,并对红外系统的模拟图像和真实图像进行匹配获得最优化估计的目标位置、尺寸以获取目标的所有灰度值,而后根据亮度与灰度的关系对积分时间进行调整。实验结果证明,可同时调整两个不同红外相机的积分时间以保证灰度值处于理想区间内,调整频率可达25Hz,满足高速飞行器试验的实时性要求。 相似文献
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随着红外探测与红外制导技术的发展,军用目标的红外隐身及其评估技术的研究具有越来越重要的军事意义。低发射率膜层是军用目标红外隐身的重要手段之一,低发射率膜层的红外隐身效果评估是研制低发射率膜层的基础。综合考虑目标与外部环境间的对流和辐射换热关系,建立了涂有膜层的目标的温度与红外辐射特性的模型,编制了相应的数值计算程序。针对两种低发射率膜层,计算了添加膜层前后目标表面温度和红外辐射随时间的变化规律,以此分析了膜层的红外隐身效果。结果表明,膜层发射率的选择应考虑被膜层控制的波长以及外部环境的综合影响。 相似文献
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提出了一种基于遥感信息的前视末制导地面目标红外场景生成方法。首先,利用遥感信息生成目标区域可见光三维场景,作为场景仿真的基础模型;然后,通过建立目标及背景的温度模型、红外温度-辐射模型,计算出目标及背景的红外辐射值,针对仿真目标区域的特点进行建模仿真。最后,采用了一种基于可见光纹理的背景真实感合成方法,增强场景的仿真效果。通过对比实测温度和红外实时图以及灰度相关匹配实验,结果表明,本文方法真实地反映了目标区红外辐射变化规律,具有较好的逼真程度。 相似文献
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玻璃钢锚杆加载过程红外辐射实验研究 总被引:2,自引:0,他引:2
应用红外探测技术,对玻璃钢锚杆进行了单向拉伸的红外辐射实验研究,结果表明:玻璃钢锚杆拉伸过程中,其红外辐射温度随着荷载的增加而增加,弹性阶段温升变化微小,塑性阶段温升明显,尤其是临近破裂时,温度升高最快,最大温升值为0.3℃.利用玻璃钢锚杆材料的红外辐射温度特征,可以反演该种材料的锚杆与围岩相互作用过程中的应力、应变以及变形等力学性质. 相似文献
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红外测量技术在MOCVD中的应用 总被引:1,自引:0,他引:1
简要说明了红外辐射测量技术的工作原理与理论基础以及红外测量的特点.MOCVD硅片外延生长过程中反射率是实时变化的,但传统红外测量方法无法实现反射率的实时测量,因此造成较大的测量误差,无法准确反应外延片的表面温度,同时无法实现对生长速率的在位测量.德国AIXTRON公司的MOCVD测量系统中加入了由脉冲信号控制的LED红外发光器件,实现了温度与反射率、生长速率与膜厚的在位实时测量,从而达到对温度和膜厚的精确控制,取得良好的实验效果. 相似文献
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介绍了非晶YBCO薄膜用作非制冷热释电红外探测器材料。它在室温下显示出强的热释电行为,并且容易在室温下采用射频磁控溅射法沉积,制备工艺与CMOS工艺相兼容,是
一种很有潜力的热释电探测器材料。并介绍了非晶YBCO热释电薄膜的研究现状,阐述了该薄膜及其探测器的制备技术和研究动向。 相似文献
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Misra M. Kataria N.D. Pinto R. Tonouchi M. Srivastava P. 《Applied Superconductivity, IEEE Transactions on》2001,11(4):4128-4135
The microwave surface resistance, Rs measurement of YBa 2Cu307 -δ (YBCO) thin film deposited on 10 mm × 10 mm LaAlO3 substrate using three prime resonating techniques, namely, cavity end plate substitution technique (20 GHz), dielectric resonator technique (18 GHz), and microstrip resonator technique (5 GHz), is reported. In addition, theoretical analysis for each technique has been performed to calculate the relative percentage error in the measured Rs -value of the YBCO thin film as a function of temperature. It has been found that the shielded dielectric resonator provides far better sensitivity for R.-measurement of the YBCO thin film with minimum relative percentage error (<4%) in the temperature range from 20 K to transition temperature of YBCO thin film compared to the other two techniques 相似文献
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Fisher M.A. Cukauskas E.J. Allen L.H. 《Applied Superconductivity, IEEE Transactions on》1997,7(1):1-6
We have investigated thin film composites of YBa2Cu3O7 (YBCO) with Ag for fluxonic device applications. YBCO/Ag composite films are produced by first depositing a layer of Ag onto a substrate and then heating the film to the YBCO deposition temperature of 680°C or higher. YBCO is deposited by off-axis sputtering onto the Ag-coated substrate. The resulting YBCO/Ag film is a composite of YBCO with well-defined Ag regions several microns in size. Scanning electron micrograph images of the films' surfaces show a background of smooth YBCO grains dotted with Ag clusters. For a wide range of increasing Ag composition, the transition temperatures of the composite films on SrTiO3 remain high, while the critical current densities have been reduced as much as 65 times. On MgO substrates, critical current density has been reduced by more than four orders of magnitude. Also on MgO, significant voltage response is seen in external magnetic fields of less than 1 mT. These measurements suggest that the films may be arrays of superconductor-normal-superconductor (SNS) junctions formed by weakly coupled YBCO grains with Ag in the grain boundaries. The field responsivity and low critical current densities of these composites make them potentially useful for fabrication of fluxonic devices 相似文献
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热释电薄膜在红外探测器中的应用 总被引:4,自引:2,他引:2
介绍了热释电效应及热释电薄膜红外探测器的工作模式,特别是探测器单元对热释电薄膜的材料与低温生长要求。为了克服薄膜生长过程中较高的基片温度对读出集成电路(ROIC)的破坏性影响,一方面发展了离子束辅助沉积、外延缓冲层等多种低温生长技术,另一方面发展了复合探测器结构设计。已研制出了性能良好的铁电薄膜非制冷红外焦平面阵列,其噪声等效温差(NEDT)可达20mK。 相似文献
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Tao Zhu Yongrui Yang Luyao Zheng Lei Liu Matthew L. Becker Xiong Gong 《Advanced functional materials》2020,30(15)
Room‐temperature solution‐processed flexible photodetectors with spectral response from 300 to 2600 nm are reported. Solution‐processed polymeric thin film with transparency ranging from 300 to 7000 nm and superior electrical conductivity as the transparent electrode is reported. Solution‐processed flexible broadband photodetectors with a “vertical” device structure incorporating a perovskite/PbSe quantum dot bilayer thin film based on the above solution‐processed transparent polymeric electrode are demonstrated. The utilization of perovskite/PbSe quantum dot bilayer thin film as the photoactive layer extends spectral response to infrared region and boosts photocurrent densities in both visible and infrared regions through the trap‐assisted photomultiplication effect. Operated at room temperature and under an external bias of ‐1 V, the solution‐processed flexible photodetectors exhibit over 230 mA W‐1 responsivity, over 1011 cm Hz1/2/W photodetectivity from 300 to 2600 nm and ≈70 dB linear dynamic ranges. It is also found that the solution‐processed flexible broadband photodetectors exhibit fast response time and excellent flexibility. All these results demonstrate that this work develop a facile approach to realize room‐temperature operated ultrasensitive solution‐processed flexible broadband photodetectors with “vertical” device structure through solution‐processed transparent polymeric electrode. 相似文献
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采用溶胶-凝胶法(Sol-Gel)在Pt/Si衬底上制备了PbTiO3 (PT)薄膜和Pb (Zrx,Ti1-x)O3(PZT)薄膜,研究了退火温度以及PT种子层对PZT薄膜结晶及压电性能的影响。X射线衍射(XRD)结果表明,制备的PZT薄膜为纯钙钛矿结构的多晶薄膜,有PT种子层的PZT薄膜晶粒尺寸更大,(110)面取向度更高,结晶性能更好;原子力显微镜(AFM)结果表明,制备的薄膜表面形貌比较平整、均匀、无裂纹;压电力显微镜(PFM)结果表明,压电力显微镜(PFM)结果表明,有PT种子层时,PZT薄膜的平均压电系数d33为128~237 pm/V,无PT种子层时平均压电系数d33为21~29 pm/V。在升温速率为10 ℃/s的退火条件下保温10 min时,随着退火温度的升高,PZT薄膜晶粒尺寸增大,粗糙度增大,(110)面取向度升高,平均压电系数d33增大。PT种子层能够有效的改善PZT薄膜的结晶性能和压电性能。 相似文献
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YBa2Cu3O7(YBCO)高温超导薄膜是重要的超导电子器件应用的材料,它们的质量对器件的运行性能至关重要。薄膜表面的颗粒使表面微波性能变坏,但有些生长在YBCO薄膜基体内部的小颗粒,会使薄膜的临界电流密度升高。 相似文献
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准分子激光扫描淀积PZT/YBCO结构铁电薄膜 总被引:2,自引:1,他引:1
利用脉冲准分子激光(工作气体XeCl,波长308nm,脉宽28ns)在外延YBCO/LaAlO3(100)单晶基片上淀积了Pb(Zr0.55Ti0.45)O3铁电薄膜,YBCO薄膜既为生长高取向PZT薄膜提供了晶体匹配条件,同时也为PZT铁电薄膜提供了下电极。讨论了工艺参数对晶相结构和表面形貌的影响。用X射线衍射表征了该多层膜的晶相结构,扫描电镜观察其表面形貌。PZT铁电薄膜的剩余极化为21μC/cm2,矫顽场为65kV/cm。 相似文献