宽量程高时间分辨扫描变像管

为改善大偏转角度的偏转像质,设计了一种高时间分辨、大扫描长度的扫描变像管电子光学和行波偏转系统。对变像管后加速技术进行了实验研究,结合图像外增强技术,解决了大面积扫描图像的探测灵敏度问题,达到了同时扩展扫描变像管的时间量程和提高时间分辨力的目的,研制出了宽时间量程、高时间分辨力的扫描变像管。初步实验表明,在量程为5 ns时,时间分辨力达到5 ps,也就是时间分辨力与时间量程之比达到1/1 000。     

高功率准分子激光系统光学设计

回顾并介绍了高功率准分子激光系统设计中需要综合考虑的两项主要技术——像传递技术和角多路技术。讨论了照明方式和激光振荡源的光束整形在激光系统成像光路设计中的重要作用,对多路放大技术及角多路放大技术形式进行了系统分析。多路激光非相干合束是角多路技术和成像技术对高功率准分子激光系统光学设计提出的特殊要求,在简要分析了透射阵列和反射式望远物镜两种实现多路激光合束的打靶光学系统基础上,提出了一种利用反射式打靶光学系统和一套光学延迟线阵列来同时实现角多路编码和解码的新型光路布局,给出了初步设计方案。     

基于双阈值视觉注意模型的图像关注焦点检测

图像关注焦点（FOA）检测是基于人眼视觉关注模型的图像感兴趣区提取的关键技术。为了更加精确、合理地搜索图像关注焦点,提出一种基于双阈值视觉关注模型的FOA检测算法。算法首先提取图像的亮度、颜色、方向和离散矩变换（DMT）特征,生成各个特征对应的特征图;然后将各特征图合并为一张包含多种特征的显著图;最后根据显著图的灰度直方图建立静态阈值与动态阈值,确定图像关注焦点的位置与数量。实验结果表明：新算法在图像关注焦点检测的准确性上较Itti模型有更为优秀的表现,更符合人眼视觉的关注习惯。     

半导体制冷片制作的高能激光靶屏

为了用热图法测量高能激光强度的时空分布,设计了将半导体制冷片作为激光靶屏的测量方案。研制了由16个50 mm×50 mm的制冷片组装成的总面积为200 mm×200 mm、总制冷功率超4 800 W的靶屏, 屏四周安装了8个红外标定物用于校正红外图像的畸变。理论上用热传导方程建立了激光辐照半导体制冷片靶屏的加热模型;数值模拟了屏表面温度分布同光强分布的关系,论证了氧化铝陶瓷材料制成的半导体制冷片作为高能激光靶屏的可行性,以及制冷片的制冷功能对测试性能的改善;通过实验验证了研制的靶屏测量光强是可行的。     

利用智能手机测定补铁药物中的铁含量*

为进一步提升图像比色法测定补铁药物中铁含量的准确性及普适性,考察了拍摄环境对结果的影响,确定了适用于图像比色分析的定量参数,比较使用不同容器来盛装溶液所获得的比色结果,在最优条件下测定了实际样品中铁的含量及加标回收率。结果显示,获得可靠数据的关键是将标准溶液、待测液以及空白溶液拍摄在同一张图片上;由溶液图像R值换算的吸光度值与浓度具有最佳的线性关系;分析以比色皿、试管、点滴板为容器获得的溶液图片,都能得到适合于定量比色分析的数据;测定的加标回收率大于95%。该方法操作简便,测定结果准确,可在各种条件下的高中化学实验室中开展。     

扫描隧道显微镜在有机化学中的应用

扫描隧道显微镜的最大优点是可达到原子量级的分辨率。本文综述了STM对有机分子的结构、聚集形态及其反应过程的研究。     

Experimental investigation of the effect of temperature on the strength of polyimide contact structures

A new photogrammetry based measurement technique for contact areas in line contact structures is developed. From the data collected by this technique, a method for measuring the contact strength of contact structures in high temperature applications is proposed. The contact strength of a line contact structure of polyimide at different temperatures is measured; the results show that the increase in temperature decreases the contact strength of the structure. The effect of temperature on the contact strength is studied by investigating the occurrence and evolution of yielding core within the structure at different temperatures. The decrease in the yield strength and elastic modulus of the polyimide material at high temperature induces core yielding at lower loads and eases the propagation of core yielding to the surface.     

Two-scale image fusion of visible and infrared images using saliency detection

Military, navigation and concealed weapon detection need different imaging modalities such as visible and infrared to monitor a targeted scene. These modalities provide complementary information. For better situation awareness, complementary information of these images has to be integrated into a single image. Image fusion is the process of integrating complementary source information into a composite image. In this paper, we propose a new image fusion method based on saliency detection and two-scale image decomposition. This method is beneficial because the visual saliency extraction process introduced in this paper can highlight the saliency information of source images very well. A new weight map construction process based on visual saliency is proposed. This process is able to integrate the visually significant information of source images into the fused image. In contrast to most of the multi-scale image fusion techniques, proposed technique uses only two-scale image decomposition. So it is fast and efficient. Our method is tested on several image pairs and is evaluated qualitatively by visual inspection and quantitatively using objective fusion metrics. Outcomes of the proposed method are compared with the state-of-art multi-scale fusion techniques. Results reveal that the proposed method performance is comparable or superior to the existing methods.     

Single image non-uniformity correction using compressive sensing

A non-uniformity correction (NUC) method for an infrared focal plane array imaging system was proposed. The algorithm, based on compressive sensing (CS) of single image, overcame the disadvantages of “ghost artifacts” and bulk calculating costs in traditional NUC algorithms. A point-sampling matrix was designed to validate the measurements of CS on the time domain. The measurements were corrected using the midway infrared equalization algorithm, and the missing pixels were solved with the regularized orthogonal matching pursuit algorithm. Experimental results showed that the proposed method can reconstruct the entire image with only 25% pixels. A small difference was found between the correction results using 100% pixels and the reconstruction results using 40% pixels. Evaluation of the proposed method on the basis of the root-mean-square error, peak signal-to-noise ratio, and roughness index (ρ) proved the method to be robust and highly applicable.     

Computational investigation toward selective collection of water particles containing odorous molecules by electrostatic spraying

The necessity of odor sensing has been increasing from environmental and health standpoints. Here, we propose the novel concept of a small device which can select odor molecules based on electrostatic spraying. For high selectivity of the target gas or odor, we conducted computational fluid dynamics coupled with an electrostatic field, as well as measurements by particle image velocimetry and anemometry. The computational model successfully reproduced characteristic features of ionic wind. Different trajectories of charged particles were computationally obtained owing to their electrical mobility. The results imply that different materials might be separated by the arrangement of the collecting electrode.