空间自适应卷积核滤波红外弱小目标检测

为了减少复杂红外图像中平滑背景边缘的影响,将具有各向异性特性的PM扩散模型应用到红外弱小目标检测,提出了空间自适应卷积核滤波检测算法,并对扩散系数进行了优化.针对模型中扩散参数难以确定的问题,提出了一种利用Sobel边缘检测算子估计扩散参数的方法.滤波后采用信噪比(SNR,Signal Noise Ratio)和接受机工作特性(ROC,Receiver Operating Characteristic)曲线进行性能评价,实验结果表明,与PM扩散模型滤波和中值滤波相比,该算法有效抑制了边缘,大大提高了信噪比,提高了检测概率,降低了虚警概率,具有更好的性能.     

Highly strained InxGa(1−x)As−InyAl(1−y)As (x>0.8,y<0.3) layers for short wavelength QWIP and QCL structures grown by MBE

Highly strained quantum cascade laser (QCL) and quantum well infrared photodetector (QWIPs) structures based on In_xGa_(1−x)As−In_yAl_(1−y)As (x>0.8,y<0.3) layers have been grown by molecular beam epitaxy. Conditions of exact stoichiometric growth were used at a temperature of 420°C to produce structures that are suitable for both emission and detection in the 2–5 μm mid-infrared regime. High structural integrity, as assessed by double crystal X-ray diffraction, room temperature photoluminescence and electrical characteristics were observed. Strong room temperature intersubband absorption in highly tensile strained and strain-compensated In_0.84Ga_0.16As/AlAs/In_0.52Al_0.48As double barrier quantum wells grown on InP substrates is demonstrated. Γ–Γ intersubband transitions have been observed across a wide range of the mid-infrared spectrum (2–7 μm) in three structures of differing In_0.84Ga_0.16As well width (30, 45, and 80 Å). We demonstrate short-wavelength IR, intersubband operation in both detection and emission for application in QC and QWIP structures. By pushing the InGaAs–InAlAs system to its ultimate limit, we have obtained the highest band offsets that are theoretically possible in this system both for the Γ–Γ bands and the Γ–X bands, thereby opening up the way for both high power and high efficiency coupled with short-wavelength operation at room temperature. The versatility of this material system and technique in covering a wide range of the infrared spectrum is thus demonstrated.     

基于聚类和最佳指数的快速高光谱波段选择方法

最佳指数法是常用的高光谱图像数据波段选择方法,但存在运算时间过长的问题。运用K-means聚类算法,对最佳指数方法进行了改进,提出了聚类最佳指数法,并进行了一系列伪装目标识别的对比实验。实验结果表明,与最佳指数法相比,改进后的方法在保证目标分类精度的前提下,运算速度提高了数十倍;与单纯使用K-means聚类运算相比,不仅运算时间缩短,而且分类精度有所提高。利用改进算法能够在伪装环境下更加快速有效地识别目标。     

A novel method for measuring optical fiber delay lines based on the optical fiber low-coherence Young's interferometer

According to the principle of double-beam interference imaging using an infrared broadband light source, a novel method based on the optical fiber low-coherence Young's interferometer for the measurement of programmable optical fiber delay line is proposed. By measuring the small length increments of delay fiber through the evaluation of the central positions of zero-order interference fringes, we successfully construct a system with a variety of important functions, such as real-time controlling, measurement and displaying. This system offers the benefit that it can be regulated precisely to generate interference stripes once again after the length of fiber segment changes. When the locations of central stripes are moved to coincide with the original markers, the determination of the corresponding fiber optical delay time becomes really simplified, as just by reading out the tinny displacement of the reference arm. Multiple groups of experimental results demonstrate the outstanding performance of the proposed system since it bears a measuring accuracy of μm and a measuring range from 1 mm to 20 cm.     

Interband and intraband radiation from the n-InGaAs/GaAs heterostructures with quantum wells under the conditions of injection in high lateral electric fields

The interband and intraband radiation from the n-InGaAs/GaAs heterostructures with the double and triple tunnel coupled and selectively doped quantum wells (QWs), which is appeared under the lateral electric field and in the presence of hole injection from the anode contact, has been investigated. A steep increase of the interband radiation intensity was found at the fields of E≥1.7 kV/cm. This effect should be related to the big lifetime of the injected charge carriers (~10⁻⁶ s) which exceeds by three orders of magnitude the lifetime in the similar bulk direct-band semiconductor. Its reason lies in spatial separation of the injected holes and electrons between coupled wells, firstly, by the built-in transverse electric field between wells and, secondly, due to the real-space transfer of carriers heated by the lateral electric field from the wide well to the narrow δ-doped one. Furthermore, an increase of the carrier concentration due to injection leads to an increase of that transition intensity and, consequently, to an intensity increase of the radiative intersubband transitions of carriers in QWs which results in a steep intensity increase of the far (50–120 µm) infrared radiation.     

非晶Ce-Ti氧化物用于NH3选择性催化还原NO的原位红外研究

采用原位红外光谱研究了在具有短程有序Ce-O-Ti结构的非晶Ce-Ti氧化物上NH₃选择性催化还原（SCR） NO_x反应. 在反应条件下,催化剂表面主要被NH₃吸附物种覆盖,而检测不到NO_x吸附物种. 经测定,NO的反应级数为0.5-0.6,表明Langmuir-Hinshelwood机理和Eley-Rideal机理同时存在. 可能的机理是NH₃吸附物种和弱吸附的NO_x反应,生成NH_yNO₃ （y = 0-4）活性中间物种,并通过GAUSSIAN计算和原位红外结果证实了它们的存在. Ce-O-Ti结构中Ce与Ti之间表现出原子尺度的相互作用,所以在SCR反应的活性温度窗口下,催化剂的氧化还原活性提高.     

红外光谱法在双亲性化合物水溶液体系研究中的应用

浓度，温度，压力，体系组分及不同分子间相互作用等因素对双亲性化合物分子在水溶液体系中的聚集状态及相变过程均有影响。本文综述了富里叶变换红外光谱方法在这一研究领域内应用十余年间的研究进展。     

基于小波变换的航空红外图像目标的多尺度识别

提出了一种基于高斯小波变换的航空红外图像的目标边缘自动提取的新方法,并利用 目标边缘特征结合目标边缘特征数据库对目标进行识别。该方法利用小波变换良好的噪声抑制能力及完备的边缘保持能力;能够有效的对红外图像进行目标边缘提取、目标增强及噪声抑制等预处理工作,利用得到的边缘特征及数据库,较好的完成红外目标的多尺度识别。     

热释电红外摄像机斩波调制电路的设计

本文提出了热释电红外摄像机斩波调制的电路模型，并对此电路模型进行了具体的电路设计和分析。     

红外系统的光机热一体化设计

在无热光学系统设计中,考虑机械结构的热性能对系统热稳定性的贡献,在满足系统总光焦度要求、消热差和消色差条件下,求解各光学组元的光焦度.在保持光焦度不变的条件下,进行像差平衡,可设计出实际的消热差光学系统.这种在光学设计中融合机械结构热稳定性因素的一体化设计方法,对红外无热光学系统设计具有重要意义.文中详细介绍了f'=45.4mm,D/f'=1/2.5,2ω=lO°的红外成像物镜和f'=160mm,D/f'=1/8,2ω =2.8°的可见/近红外波段干涉成像光谱仪前置镜的一体化无热设计的结果.