1 西安工业大学 光电工程学院, 陕西 西安 710021
2 陕西省光电测试与仪器技术重点实验室, 陕西 西安 710021
3 中国兵器装备集团公司黑龙江北方工具有限公司, 黑龙江 牡丹江 157000
镜头式探测器配接L形LED光源构成大面积矩形探测光幕, 常用来布置在封闭的室内靶道测量外弹道参数, 其探测区域的灵敏度大小直接影响测量精度, 文章研究和分析了配接L形LED光源的10m×10m大面积矩形探测光幕灵敏度空域分布规律, 考虑镜头边缘效应和光传播路径损失, 将飞行弹丸遮挡的光投射到镜头处计算光电器件接收的光通量变化, 推导出探测光幕灵敏度的数学表达式, 将探测区域分割成小块, 采用数字仿真方式计算同一口径弹丸穿过不同区域块引起的光通量变化, 得到矩形探测光幕区域灵敏度空域分布。结果显示矩形探测区域灵敏度呈现对称分布, 靠近镜头主光轴和镜头附近处时, 会得到探测区域内的较大探测灵敏度。其研究结果为后续进行大靶面外弹道测试相关技术提供了理论依据。
应用光学 大面积探测光幕 空域灵敏度分布 L形光源 applied optics large area detection light screen spatial sensitivity distribution L-shaped light source
中北大学信息与通信工程学院, 山西 太原 030051
气固两相流广泛存在于工业生产的材料输送中,静电法由于具有成本低、易检测、适应性强等优点而被广泛应用在两相流的测量中。基于静电感应原理, 采用有限元分析法对传感器的结构参数(管壁厚度、电极宽度、电荷、位置等)进行了设定;在不同电极宽度下,对传感器的空间灵敏度进行了研究;根据静电传感器的静动态特性,研究分析了传感器的幅频特性。经仿真实验得出:静电传感器在空间频域上具有低通滤波特性;粒子通过管道时,越靠近管道中心,空间频带越窄;粒子在管道中的速度越快,传感器的频带越宽;电极的轴向长度越长,信号的振幅越大。在确定电极宽度的情况下,可以得到电极在管道内的最佳感测范围。
测量 静电传感器 感应电荷量 空间灵敏度 频率响应特性 激光与光电子学进展
2020, 57(17): 171202
Author Affiliations
Abstract
1 State Key Lab Elect Thin Film & Integrated Device and Department of Biomedical Engineering, University of Electronic Science & Technology of China, Chengdu 610054, P. R. China
2 Design Department No. 2, Avic Beijing Keeven Aviation Instrument Co. Ltd, Beijing 100086, P. R. China
Modeling Light propagation within human head to deduce spatial sensitivity distribution (SSD) is important for Near-infrared spectroscopy (NIRS)/imaging (NIRI) and diffuse correlation tomography. Lots of head models have been used on this issue, including layered head model, artificial simplified head model, MRI slices described head model, and visible human head model. Hereinto, visible Chinese human (VCH) head model is considered to be a most faithful presentation of anatomical structure, and has been highlighted to be employed in modeling light propagation. However, it is not practical for all researchers to use VCH head models and actually increasing number of people are using magnet resonance imaging (MRI) head models. Here, all the above head models were simulated and compared, and we focused on the effect of using different head models on predictions of SSD. Our results were in line with the previous reports on the effect of cerebral cortex folding geometry. Moreover, the influence on SSD increases with the fidelity of head models. And surprisingly, the SSD percentages in scalp and gray matter (region of interest) in MRI head model were found to be 80% and 125% higher than in VCH head model. MRI head models induced nonignorable discrepancy in SSD estimation when compared with VCH head model. This study, as we believe, is the first to focus on comparison among full serials of head model on estimating SSD, and provided quantitative evidence for MRI head model users to calibrate their SSD estimation.
Visible chinese human functional near-infrared spectroscopy Monte Carlo simulation head model spatial sensitivity distribution Journal of Innovative Optical Health Sciences
2015, 8(5): 1550024
