光子学报
2023, 52(10): 1052405
Author Affiliations
Abstract
1 The Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
2 Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
We report on a long wavelength interband cascade photodetector with type II InAs/GaSb superlattice absorber. The device is a three-stage interband cascade structure. At 77 K, the 50% cutoff wavelength of the detector is 8.48 μm and the peak photoresponse wavelength is 7.78 μm. The peak responsivity is 0.93 A/W and the detectivity D* is 1.12 × 1011 cm·Hz0.5/W for 7.78 μm at –0.20 V. The detector can operate up to about 260 K. At 260 K, the 50% cutoff wavelength is 11.52 μm, the peak responsivity is 0.78 A/W and the D* is 5.02 × 108 cm·Hz0.5/W for the peak wavelength of 10.39 μm at –2.75 V. The dark current of the device is dominated by the diffusion current under both a small bias voltage of –0.2 V and a large one of –2.75 V for the temperature range of 120 to 260 K.We report on a long wavelength interband cascade photodetector with type II InAs/GaSb superlattice absorber. The device is a three-stage interband cascade structure. At 77 K, the 50% cutoff wavelength of the detector is 8.48 μm and the peak photoresponse wavelength is 7.78 μm. The peak responsivity is 0.93 A/W and the detectivity D* is 1.12 × 1011 cm·Hz0.5/W for 7.78 μm at –0.20 V. The detector can operate up to about 260 K. At 260 K, the 50% cutoff wavelength is 11.52 μm, the peak responsivity is 0.78 A/W and the D* is 5.02 × 108 cm·Hz0.5/W for the peak wavelength of 10.39 μm at –2.75 V. The dark current of the device is dominated by the diffusion current under both a small bias voltage of –0.2 V and a large one of –2.75 V for the temperature range of 120 to 260 K.
interband cascade infrared photodetector type II superlattices long wavelength Journal of Semiconductors
2023, 44(4): 042301
Author Affiliations
Abstract
School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China
Accurate measurement of the thin liquid film thickness in pipes is the foundation for studying the characteristics of the film. In this paper, an interferometry-based measurement of liquid film thickness in transparent pipes is developed, which can greatly improve the accuracy, extend the lower limit of measurement and provide a new technical approach for the calibration and traceability. The light intensity distribution is established based on the optical path analysis and a mathematical model. A new algorithm to solve the direction ambiguity is developed to reconstruct the phase distribution. Besides, the effect of the pipe wall is taken into account, which can be suppressed by:image subtraction and enhancement technology. The proposed method is of high accuracy and robustness, whose reconstruction errors are 0.064% and 0.25% for the smooth and slight fluctuating liquid films, respectively.
光电子快报（英文版）
2022, 18(8): 489
Author Affiliations
Abstract
1 School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
2 State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China
This paper presents a new three-dimensional (3D) volume measurement approach of bubble in gas-liquid two-phase flow. According to the dual perspective imaging principle, bubble feature images can be captured from two different view angles. The least square ellipse fitting algorithm is used to figure out the feature parameters from the captured images. Then the 3D volume of bubble can be quantitatively measured. Compaerd with the traditional volume estimation methods based on single perspective imaging, it can effectively reduce the loss of bubble feature information. In the experiment, the 3D volume reconstruction of bubbles from dual perspective images is conducted, and the variation of bubble volume in the bubble rising process is studied. The results show that the measurement accuracy based on the proposed 3D method is higher than those based on traditional methods. The volume of rising bubble is periodically changed, which indicates that bubble achieves periodic rotation and deformation in the rising process.
光电子快报（英文版）
2017, 13(1): 70
天津大学 电气自动化与信息工程学院，天津 300072
以气液两相环状流管道横截面的周向液膜为测量对象，采用单台高速摄像机和平面反射镜组构建了虚拟双视角的视觉传感器，并对传感器进行了优化。基于虚拟双目立体视觉原理建立虚拟双视角视觉传感器测量模型。为了尽可能增大有效拍摄视角以获得更多液膜流动信息，综合考虑视场区域、传感器尺寸、测量距离以及管道光路折射等因素，对虚拟双视角视觉传感器模型进行了分析和设计，优化了传感器模型的结构参数。理论分析及实验结果表明：优化后的虚拟双视角视觉传感器可以获得近300°的有效周向测量视角，远远优于使用单台高速摄像机进行直接拍摄。该项研究为通过双视角视觉传感器进行气液两相环状流周向液膜的实时测量提供了理论基础，对研究液膜厚度和分析环状流流动状态具有重要意义。
视觉传感器 环状流 周向液膜 有效视角 优化设计 vision sensor annular flow circumference liquid films effective visual angle optimization 光学 精密工程
2017, 25(12): 3145
广东省量子调控与材料重点实验室, 华南师范大学物理与电信工程学院, 广东 广州 510006
用超声驱动方法合成了CdSe/TiO2复合纳米粒子, 并通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、紫外可见光(UV-Vis)吸收光谱和荧光(FS)光谱对CdSe/TiO2复合纳米粒子进行表征。使用CCK-8法测定CdSe/TiO2对白血病细胞的可见光光催化活性并通过SEM研究HL60细胞的表面超微结构形态。实验结果表明, 用CdSe/TiO2复合纳米粒子处理的组中观察到明显的HL60细胞生长抑制, 并且HL60细胞在CdSe掺杂TiO2复合纳米粒子作用下的PDT效率显著高于TiO2, 表明可以通过CdSe的修饰有效增强TiO2的可见光光催化活性。此外, CdSe/TiO2在可见光辐照下在4 μg/mL的终值浓度下显示非常高的光动力效率, 达76%。荧光光谱分析表明, CdSe/TiO2复合纳米粒子可能通过分离光生空穴电子对提高此复合纳米粒子的光催化活性, 从而提高CdSe/TiO2对HL60细胞的PDT灭活效率。
锐钛矿TiO2 CdSe/TiO2复合纳米粒子 光动力疗法(PDT) HL60细胞 anatase TiO2 CdSe/TiO2 composite nanoparticle photodynamic therapy leukemia HL60 cells CCK-8 CCK-8
1 天津大学 电气与自动化工程学院, 天津 300072
2 天津市过程检测与控制重点实验室, 天津 300072
为测量密集气液泡状流的流动形态及参数, 建立了基于激光扫描的三维可视化测量系统。采用片状激光结合旋转正多边形棱镜实现对流场的光学扫描, 高速摄像机采集扫描切片图像, 首先对图像进行预处理。针对扫描成像中产生的切片重复曝光问题, 提出二阶微分平均卷积优化算法, 该方法不仅可以有效提取多切片图像中重复曝光的特征点, 而且可以去除冗余及噪声信息。实验结果表明, 针对分散相遮挡的密集泡状流, 基于激光扫描可完整重建其三维结构, 二阶微分优化算法可以有效降低重建畸变影响, 重建后体积含气率的相对误差优于6%。激光扫描方法非侵入、重建精度高, 具有传统方法不可比拟的优势。
光学三维测量 激光扫描 密集泡状流 三维重建 模板卷积 含气率 optical three-dimensional measurement laser scanning dense bubbly flow three-dimensional reconstruction template convolution void fraction
1 广东省量子调控与材料重点实验室, 华南师范大学物理与电信工程学院, 广东 广州 510006
2 广东工业大学物理与光电工程学院, 广东 广州 510006
文章主要研究叶酸修饰硫掺杂二氧化钛(FA-S-TiO2)纳米颗粒光催化灭活作用并初步探讨FA-S-TiO2增强了TiO2光催化灭活效率的作用机理。利用固相反应的方法制备了S-TiO2, 并利用表面修饰的方法制备了FA-S-TiO2。通过紫外-可见光吸收光谱(UV-Vis),荧光光谱, 傅里叶红外光谱(FTIR), 透射电镜(TEM)等手段对样品进行了表征。利用Cell Counting Kit-8(CCK-8)法分别检测TiO2、S-TiO2、FA-S-TiO2对HL60细胞的灭活效应, 并采用活性氧检测等方法进行了分析研究。细胞实验结果表明, 在暗室条件下, 随着叶酸修饰S-TiO2的比例增加, 细胞的存活率随之减少; 在光照条件下, 细胞的存活率明显下降。其中FA-S-TiO2样品1对HL60细胞的灭活效率最高, 达到72%。其相应的活性氧含量也是最高。同时, 通过荧光光谱推测FA-S-TiO2提高HL60细胞对该纳米颗粒摄取效率, 进而增强PDT灭活效果。
FA-S-TiO2纳米颗粒 光动力疗法(PDT) HL60细胞 FA-S-TiO2 nanoparticles photodynamic therapy(PDT) leukemia HL60 cells.
1 安徽大学生命科学学院, 安徽 合肥 230039
2 中国医学科学院肿瘤研究所, 北京 100021
酵母甘露聚糖(Mannan, 简称Man)是能参与生物信息流影响生物体、特别是在糖基化方面起着重要调控作用的生物信息大分子。它是否能在抑制生物机体中肿瘤生长方面具有重要作用？研究结果表明: 酵母甘露聚糖既能使患S-180瘤鼠的体质增强的同时又有抑制其体内所患S-180瘤生长的功效。Man抑制患鼠机体内的S-180瘤生长的功效(抑瘤率)随用量的增加而提高, 当Man用量达360 mg(40 mg/Kg/d·9d)时, 其抑瘤率达98.4%的最高水平, 此时鼠体重增加1.66倍。Man的抑瘤功效有最佳适用量并存在性别敏感性, 通常是雄性鼠的抑瘤率高于雌性鼠。Man抑制鼠S-180肿瘤生长的作用优于市售5-氟尿嘧啶的作用。
生物大分子功能 酵母甘露聚糖 S-180瘤 抑制 抑瘤率 最佳用量与性别敏感性 体重增长 biomacromolecule function Yeast Mannan(Man) inhibition Sarcoma-180 tumor weight growing inhibition ratio sensitive to amount of Man and mice’s sex promote mice’s weight
1 天津大学 电气与自动化工程学院,天津 300072
2 天津市过程检测与控制重点实验室, 天津 300072
研究了基于虚拟立体视觉的气液两相流三维测量系统的标定技术。首先, 基于单台高速摄像机和两组反射镜组构建虚拟立体视觉测量系统, 建立高速摄像机透视投影变换模型以及虚拟立体视觉三维测量模型, 对虚拟立体视觉系统中摄像机及虚拟立体视觉传感器进行标定。用靶标基准球模拟气泡在水中的分布, 以其空间距离作为测量评价指标, 比较了不同标定方法对三维重建精度的影响。实验结果表明, 将标定参照物置于水箱内, 并且分别对左、右虚拟摄像机及传感器进行标定, 三维重建精度最高, 测量空间距离绝对误差优于0.13 mm, 相对误差优于0.49%。实验认为, 对基于虚拟立体视觉的气液两相流三维测量系统进行标定时, 必须充分考虑折光分光光路以及管壁折射对三维重建所带来的影响。
气液两相流 三维测量系统 虚拟立体视觉 标定 误差分析 gas-liquid two phase flow three-dimensional measurement system virtual stereo vision calibration error analysis
