Abstract:Recent progress of infrared photoreflectance and modulated photoluminescence techniques was outlined with special attention focused on the significant improvement of signal-to-noise ratio, spectral resolution and time consumption relative to the conventional techniques. Application of these techniques to molecular beam epitaxially grown HgCdTe films was given as examples, from which the potential impact of the techniques was foreseen on the optical study of narrow-gap semiconductors and inter-subband transition of wide-gap semiconductors with low-dimensional structures.

Abstract:报道了用分子束外延(MBE)方法生长掺杂InGaAs的PIN InP/InGaAs/InP外延材料,通过台面制作、硫化处理、ZnS/聚酰亚胺双层钝化、电极生长等工艺,制备了256元正照射台面InGaAs线列探测器,278K时平均峰值探测率为1.33×1012 cmHz1/2W-1.测试了不同钝化方式探测器典型Ⅰ-Ⅴ曲线和探测率,硫化可以减小探测器暗电流,ZnS/聚酰亚胺双层钝化效果最好.并对ZnS/聚酰亚胺双层钝化InGaAs探测器进行了电子辐照研究.256元InGaAs探测器阵列与两个CTIA结构128读出电路互连并封装,在室温时,焦平面响应率不均匀性为19.3%.成功实现了室温扫描成像,图像比较清晰.

Abstract:采用聚碳酸酯毛细管作为红外空芯光纤的基管材料,制作了内直径为320微米的细径红外空芯光纤.内面镀有光滑银膜的聚碳酸酯毛细管,在近红外和中远红外波段获得了平坦的损耗-波长响应特性.用224根镀银聚碳酸酯空芯光纤,制作了长度40mm,截面积约50m2的红外图像光纤束.利用该红外光纤束成功进行了加热电阻丝的红外热图像传输实验.红外聚碳酸酯空芯光纤束具有柔韧性强、无毒等特点,在医疗及工业领域有广阔的应用前景.

Abstract:A Ka-band second-harmonic gyrotron traveling wave amplifier with multi-stage loss waveguide was studied. By stability analysis, the parameters were determined. A 35GHz TE02 mode second harmonic three-stage distributed-loss gyro- TWT was presented and the optimized design was carried out. Then the nonlinear analysis was presented to study the interaction between electron beam and wave. The results indicate that the interaction structure can suppress the parasitic modes effectively, meanwhile, 125kW output power and 39dB gain are obtained when the beam velocity spread is 3%. The 3dB bandwidth is 4.3%.

Abstract:Based on the four step method, a method for deriving soil mid-infrared emissivity was put forward. The first step, soil temperature was inversed by the ISSTES algorithm from thermal infrared data; The second step, the soil temperature was introduced to make the inversion equation complete in mid-infrared domain ; The third step, the least square meth- od was applied to solve the formulations and then the mid-infrared emissivity was obtained. More attention was paid to analyze the impacts of instrument calibration error and simplification of radiative transfer equation on the extraction of soil emissivity in mid-infrared. Finally, the reason for large error of emissivity inversion in some bands of mid-infrared was pointed out based on the simulated data.

Abstract:太阳探头响应的能量是太阳可见光辐射.在卫星轨道,地球大气和表面产生的反射光照也能进入太阳探头的视场.针对风云一号C星和风云三号气象卫星,综合考虑了卫星发射的窗口、轨道、大气漫反射和太阳直射等因素,从理论上分析和推算了太阳探头响应地表及大气反照的各种结果,并作为风云一号C星姿控系统复核复算的依据.也可为风云三号卫星姿控系统提供参考.

Abstract:提出了一种新型的基于左手介质的介质栅波导阻带滤波结构,并采用多模网络与严格模匹配相结合的方法,对该左手介质栅波导阻带滤波特性进行仔细严格的分析;给出了主模的Brillouin图,以及滤波结构的归一化中心频率、阻带的宽度和带内最大衰减等特性和结构参数的关系,并与传统右手介质栅波导作了比较,说明了产生两者不同特性的原因.数值结果表明左手介质栅波导的阻带带宽和带内衰减要比通常介质栅波导的阻带带宽和带内衰减大得多.这些计算结果对于所提新型带阻滤波结构的设计有指导意义.

Abstract:用液相外廷方法在LaAlO3(001)、MgO(001)、SrTiO3(001)以及SrTiO3(001)/PZT(001)衬底上制备了PZNT薄膜.结果表明在LaAlO3,(001)村底上获得的PZNT薄膜的晶粒以三维岛状自发形式生长发育,而且薄膜中有大量的焦绿石异相晶粒存在;在MgO(001)和SrTiO3(100)衬底上,晶粒为三维岛状异质外廷生长,薄膜中焦绿石异相几乎消失;在SrTiO3(001)衬底引入(100)取向的PZT种膜后,膜中晶粒生长变为二维生长,获得了完整的PZNT膜,显著改善了外延膜的质量.分析了衬底取向对紧邻层纳米尺寸范围的晶粒形成、薄膜晶粒的发育、克服薄膜中异相形成等的影响.

Abstract:Based on the coaxial three-reflective system, a space off-axial three-reflective system applied to observe the earth on the geostationary orbit was designed by means of field of view off-axis form. The characteristics of the system are both large linear field of view and large relative aperture. The results of design indicate that the quality of imaging is so high as to have arrived at the diffraction-limitation.

Abstract:For segmenting weak and small target image in infrared imaging guidance systems, a new automatic segmentation method based on cellular automata was proposed. First, the image contrast was enhanced by using cellular automata, and a von Neumann neighborhood with a uniform cellular automaton rule was adopted for the state transition function. Then, the image was binarized by using the method of dual edge thresholds. Finally, the target blocks were labeled and filtered according to seed points and target complexity. In this way the accurate results of image segmenting were obtained. In the segmentation experiments for three different types of infrared images captured in the outfield, the proposed method can locate effectively the region of multiple weak and small targets, which facilitates the subsequent target recognition and tracking.

Abstract:Fukunnga-Koontz变换作为一种两类模武识别工具,源自主成分分析,只能提取图像的二阶统计特征,没有考虑图像的高阶统计特征,用于红外小目标检测时难以达到满意效果.为了提高目标检测性能,本研究首先将Fuku-naga-Koontz变换推广到高维核特征空间,成为核Fukunaga-Koontz交换,以提取图像的高阶统计特征,从而利用核Fukunnga-Koontz变换来检测红外小目标.

Abstract:为实现啤酒糖度和pH值的快速检测,采用可见/近红外光谱仪器得到360个啤酒样本的可见/近红外光谱数据.使用主成分分析(PCA)对数据进行降维处理以消除众多信患共存中相互重叠的部分,得到6个主成分值.将样本数据随机分为定标集和预测集,利用最小二乘支持向量机(LS-SVM)算法在定标集数据基础上建立啤酒糖度和pH值预测模型,并利用此模型对预测集样本进行预测.根据预测相关系数(r)和预测标准偏差(RMSEP)判断预测模型好坏,结果表明该模型对啤酒糖度预测的相关系数r为0.9829,RMSEP为0.1506;对啤酒pH值的预测相关系数r为0.9563,RMSEP为0.0494,预测精度明显高于神经网络和PLS预测,所以利用该模型能够准确的预测啤酒的糖度及pH值.

Abstract:采用苏木精一伊红(HE)染色法对8毫米波辐照不同时间的小鼠皮肤组织切片染色.结果表明随着辐照时间的增加,组织损伤也在逐步加深.建立了考虑血流灌注和水分蒸发失热的一维生物热传导模型,数值计算得出动物表皮温升,计算结果与实验测定结果吻合较好.进一步计算得到了不同辐照时间,动物皮肤不同深度的温升.理论计算和实验相结合,得到了温度与组织损伤之间的关系,结果表明当组织温度上升约16℃时,可以引起组织形态的明显变化.

Abstract:首次研究了TM模的光折变表面波,理论上分别推导了扩散机制下的TE和TM模式的光折变表面波的非线性波方程.通过数值计算分别得到不同传播常数下两种模式光折变表面波振幅空间分布.对TM模式表面波和TE模式表面波的特性进行了比较.讨论了背景光和暗辐照等参量对TM模式表面波的影响.研究结果表明TM模表面波由于晶体各向异性使得Ex、Ez两个光波电矢量分量数值上相差较大,表面波的能量主要集中于Ex分量上;并且Ex分量比Ez分量从表面到体内振幅衰减更快速,能量被更好地约束在表面;背景光和暗辐照可明显影响TM模式光折变表面波从表面到体内的衰减速度.TM模式表面波随传播常数、背景光和暗辐照等参量的变化的规律与TE模类似.

Abstract:基于柯西分布统计模型和梯度信息,提出了一种用于热成像(红外)图像序列中行人目标检测的统计背景剔除方法.它不依赖传统红外行人检测方法的"热场"(hot-spot)假设(即认为人体区域总比周围环境热),而是用一种快速动态背景的重建方法建立初始化背景Gaussian模型,简化了Cauchy分布的参数估计问题.基于Gauchy分布的背景剔除被首先用来识别局部兴趣区域(Regions-Of-Interest,ROI).在每个兴趣区域将当前图像和背景图像的梯度信息组合成一个梯度图.对梯度图进行各向异性滤波和运用最大类间方差法进行自适应阈值处理后获得行人目标区域.经多组实验及与其他方法比较,结果表明提出的方法对热成像红外视频人体目标的位置和形状实现了较精确的检测,对环境、时间变化、极性翻转、"晕轮"效应等产生的影响,以及背景中杂波的干扰具有较好的鲁棒性.

Abstract:对Chan-Vese提出的基于简化Mumford-Shah模型的水平集图像分割方法(C-V模型)做了改进.传统的C-V模型仅将灰度同(homogeneity)作为区域分离准则,这使其对于对比度明显的图像能够取得很好的分割结果.但单一的分离准则往往致使其在分割噪声信息丰富的、灰度分布复杂的医学、遥感以及自然图像等时产生大量的冗余轮廓.为此,本文在改善C-V模型全局优化特性的基础上,整合图像的灰度分布信息、邻域空间信息以及图像所固有的模糊信息构造三维向量(灰度值、模糊均值和模糊中值),提出了一种基于三维直方图的改进C-V模型水平集图像分割方法.自然图像和红外光学图像的试验结果证明了该方法的有效性.

Abstract:There are several typical methods for SAR image superresolution, such as spectrum estimation, regularization, basis pursuit and partial differential equation methods. The relationship of these methods was discussed to provide reference for their synthetic application. First, the sameness and difference of different methods in prior utilizing, problem modeling, and parameters estimating were discussed. Second, the application bound of each method and the selection of methods in engineering application was given. Last, several thoughts for synthetic model were given. The simulation results confirm the merit of synthetic method.