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Gas microchannel plate-pixel detector for X-ray polarimetry
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作者 Huan-Bo Feng Hong-Bang Liu +16 位作者 Dong Wang Zi-Li Li Shu-Lin Liu Qian Liu Hang-Zhou Li Bin-Long Wang Yan-Jun Xie Zong-Wang Fan Hui Wang Ran Chen Di-Fan Yi Rui-Ting Ma Fei Xie Bo Peng Xiang-Ming Sun Jin Li En-Wei Liang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期60-73,共14页
POLAR-2 is a gamma-ray burst(GRB)polarimeter that is designed to study the polarization in GRB radiation emissions,aiming to improve our knowledge of related mechanisms.POLAR-2 is expected to utilize an on-board polar... POLAR-2 is a gamma-ray burst(GRB)polarimeter that is designed to study the polarization in GRB radiation emissions,aiming to improve our knowledge of related mechanisms.POLAR-2 is expected to utilize an on-board polarimeter that is sensitive to soft X-rays(2-10 keV),called low-energy polarization detector.We have developed a new soft X-ray polari-zation detector prototype based on gas microchannel plates(GMCPs)and pixel chips(Topmetal).The GMCPs have bulk resistance,which prevents charging-up effects and ensures gain stability during operation.The detector is composed of low outgassing materials and is gas-sealed using a laser welding technique,ensuring long-term stability.A modulation factor of 41.28%±0.64% is obtained for a 4.5 keV polarized X-ray beam.A residual modulation of 1.96%±0.58% at 5.9 keV is observed for the entire sensitive area. 展开更多
关键词 X-ray polarimetry Gas microchannel plate-pixel detector Gamma-ray bursts
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天空可见-近红外光谱偏振态自动测量仪设计 被引量:1
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作者 王昊 孙晓兵 +2 位作者 刘晓 宋强 洪津 《大气与环境光学学报》 CAS CSCD 2024年第1期111-124,共14页
太阳光在地球大气传输过程中产生的散射会呈现出固有的偏振特性,因此利用大气散射偏振态分布特性及其与太阳照射几何以及地表观测几何之间存在的对应关系,为地球大气层内导航提供了可能。然而因气象变化造成的大气组分改变会直接影响光... 太阳光在地球大气传输过程中产生的散射会呈现出固有的偏振特性,因此利用大气散射偏振态分布特性及其与太阳照射几何以及地表观测几何之间存在的对应关系,为地球大气层内导航提供了可能。然而因气象变化造成的大气组分改变会直接影响光散射分布,从而影响基于偏振态分布的方向定位精度,因此在偏振导航实际应用过程中,其方向指引精度受大气状况影响较大。为研究不同气象条件下天空偏振态变化内在机理,研制了一台天空可见-近红外光谱偏振态自动测量仪。该仪器可按需进行定时段、定天区、多天候天空光谱偏振态测量,采用分时偏振同时分谱非成像测量体制。仪器主要由偏振分析模块、偏振检测方位定位驱动电机、微型光谱仪、GPS定位模块、嵌入式采集控制模块、二维载重转台等部分组成,光谱范围为390~960nm,光谱分辨率为1.5nm,观测视场为3°,光谱线偏振度测量精度优于98.85%,偏振角测量精度优于0.1°,单点观测时间小于9s。经实验室定标和外场测试,表明该仪器可在多种气象条件下稳定观测天空光谱偏振态,其测量数据可用于天空偏振态影响机理相关研究。 展开更多
关键词 天空光 散射 偏振测量 气溶胶 光谱
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一种基于量子相干对在铷原子气体中同向传输激光计量偏振特性技术的研究
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作者 贾云峰 刘卫平 +6 位作者 李栋 俞兵 张云龙 尤越 王楠茜 陈洁婧 刘译泽 《宇航计测技术》 CSCD 2024年第5期74-80,共7页
为解决激光在气体介质传输过程中的偏振计量问题,提出一种利用两束同方向传输的激光在铷原子气体介质中的量子相干效应,通过斯托克斯偏振反演方法对其中一束激光的光强分布探测,从而获得另一束激光的偏振分布情况的方法。具体实现方式... 为解决激光在气体介质传输过程中的偏振计量问题,提出一种利用两束同方向传输的激光在铷原子气体介质中的量子相干效应,通过斯托克斯偏振反演方法对其中一束激光的光强分布探测,从而获得另一束激光的偏振分布情况的方法。具体实现方式是将两束激光同时穿过铷原子气体,通过改变其中一束激光的偏振方位角和椭偏度,研究另一束探测激光在通过铷原子气体后光强以及偏振变化情况,并通过将一束激光换为混合矢量光与角向矢量光的试验方式验证了试验结论。研究发现当两束激光偏振方向和椭偏度相同时,激光的光强达到最大,但偏振分布不变。为此提出量子相干的数学模型进行解释,并最终通过跃迁能级相干时间检测试验验证了所提出的量子相干数学模型的可行性。 展开更多
关键词 量子相干性 激光传输 单原子气体 斯托克斯偏振测量
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Depolarization Degree to Determine Dihedral Attribute of Radar Target
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作者 Faisal Aldhubaib 《Journal of Electromagnetic Analysis and Applications》 2024年第6期85-101,共17页
This paper investigates the ability of the depolarization degree, derived from the characteristic polarization states at the resonant frequency set, to identify corner or swept, i.e. dihedral, changes in same-class ta... This paper investigates the ability of the depolarization degree, derived from the characteristic polarization states at the resonant frequency set, to identify corner or swept, i.e. dihedral, changes in same-class targets by a metallic wire example. A well-estimated depolarization degree requires a robust extraction of the fundamental target resonance set in two orthogonal sets of fully co-polarized and cross-polarized polarization channels, then finding the null polarization states using the Lagrangian method. Such depolarization degree per resonance mode has the potential to form a robust feature set because it is relatively less sensitive to onset ambiguity, invariant to rotation, and could create a compact, recognizable, and separable distribution in the proposed feature space. The study was limited to two targets with two swept changes of fifteen degrees within normal incidence;under a supervised learning approach, the results showed that the identification rate converging to upper-bound (100%) for a signal-to-noise ratio above 20 dB and lower-bound around (50%) below −10 dB. 展开更多
关键词 polarimetry Radar Target Recognition Time-Domain Analysis Remote Sensing
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^(3)He极化系统中FID NMR线圈的优化分析及实验验证
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作者 罗庆金 吴良勇 +3 位作者 王雨婷 闫海洋 向一峰 陈思宇 《波谱学杂志》 CAS 2024年第3期266-275,共10页
超极化^(3)He气体在中子极化、基础物理和诊断医学等领域广泛应用.测量其极化率对于^(3)He极化系统至关重要.通常使用自由感应衰减核磁共振(FID NMR)线圈来检测^(3)He原子的FID信号.线圈的测量信噪比与直径、匝数、以及其与气室的相对... 超极化^(3)He气体在中子极化、基础物理和诊断医学等领域广泛应用.测量其极化率对于^(3)He极化系统至关重要.通常使用自由感应衰减核磁共振(FID NMR)线圈来检测^(3)He原子的FID信号.线圈的测量信噪比与直径、匝数、以及其与气室的相对位置等因素相关.关于FID NMR线圈的优化分析,目前仅有少量的文献提及且缺乏详细的实验验证.本文通过对FID信号和线圈噪声的理论分析,建立了线圈测量信噪比模型,并且在基于亚稳态交换光泵(Metastability-Exchange Optical Pumping,MEOP)极化技术的^(3)He极化系统中对FID NMR线圈进行了实验验证.实验结果显示,在半径和高度均为r_(cell)的柱形气室中,线圈的测量信噪比在半径为r_(cell)/2时达到最优值,此结论与理论分析结果相符.该信噪比模型的相对误差不超过10%,证明了理论模型的有效性.这些研究结果对于优化设计^(3)He极化系统具有重要的指导意义. 展开更多
关键词 自由感应衰减线圈设计 极化率测量 极化^(3)He 亚稳态交换光泵
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鉴别电子烟中天然烟碱和合成烟碱的分析方法研究进展
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作者 杨文武 况利平 《中国烟草学报》 CAS CSCD 北大核心 2024年第5期109-118,共10页
烟碱是电子烟等新型烟草制品中的核心成分之一,烟碱有天然提取和化学合成两种来源方式,如何鉴别成为近年来的研究热点。综述了8种分析方法,主要包括烟碱异构体比例法和同位素法等,对各方法的优缺点进行了讨论,并探讨了其它可能的方法。... 烟碱是电子烟等新型烟草制品中的核心成分之一,烟碱有天然提取和化学合成两种来源方式,如何鉴别成为近年来的研究热点。综述了8种分析方法,主要包括烟碱异构体比例法和同位素法等,对各方法的优缺点进行了讨论,并探讨了其它可能的方法。烟碱异构体比例法包括旋光仪法、HPLC法、GC法、SFC法和NMR法等,具有简单、快速、定性定量等特点,可作为间接鉴别的方法;同位素法包括δ^(2)H、δ^(14)C、同位素模式法等,具有准确、高效、无需定量的特点,可作为直接鉴别的方法。采用上述多种方法同时确证电子烟中的烟碱来源,将大大提高结果的准确可靠性,为产品质量控制和市场监管提供技术参考。 展开更多
关键词 电子烟 天然烟碱 合成烟碱 旋光 异构体比例 同位素法
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薄膜多参数测量系统设计及实验
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作者 孙伟 金尚忠 +2 位作者 张殷 孙紫娟 徐胜 《光电子技术》 CAS 2024年第3期248-253,264,共7页
设计薄膜多参数测量系统,对薄膜在制备后膜厚、厚度分布及薄膜残余应力等表征薄膜制备效果的参数同时进行测量,减少测量误差。通过分析椭偏测量、光谱测量和激光测量技术,设计薄膜多参数测量系统,并搭建测量系统。为验证该系统,通过RC2... 设计薄膜多参数测量系统,对薄膜在制备后膜厚、厚度分布及薄膜残余应力等表征薄膜制备效果的参数同时进行测量,减少测量误差。通过分析椭偏测量、光谱测量和激光测量技术,设计薄膜多参数测量系统,并搭建测量系统。为验证该系统,通过RC2和设计系统对不同厚度的SiO_(2)薄膜和Ta_(2)O_(5)薄膜进行测量对比实验,表明设计系统对不同薄膜厚度的测量偏差均小于0.3 nm,厚度分布测量偏差值小于0.06%;通过ZYGO激光干涉仪和设计系统对不同直径的薄膜进行对比测试实验,表明该系统的测量偏差在±1°以内。测量系统能够满足薄膜制备后对不同参数同时测量的测量需求,简化了测量过程。 展开更多
关键词 光学检测 椭圆偏振法 光谱 无损检测
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旋光法快速测定乳糖含量的研究
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作者 赵浩东 周小华 +4 位作者 赵恂 朱林 施海蔚 黄青 袁耀佐 《中国药品标准》 CAS 2024年第5期512-516,共5页
目的:建立一种快速测定乳糖(C_(12)H_(22)O_(11))含量的方法。方法:采用乳糖精制品测得纯品乳糖的比旋度值[α]^(20)_(D),计算得到校正系数,将测得样品的旋光度值,乘以校正系数得到供试品中乳糖的质量(g),即可计算得到乳糖的含量。并对... 目的:建立一种快速测定乳糖(C_(12)H_(22)O_(11))含量的方法。方法:采用乳糖精制品测得纯品乳糖的比旋度值[α]^(20)_(D),计算得到校正系数,将测得样品的旋光度值,乘以校正系数得到供试品中乳糖的质量(g),即可计算得到乳糖的含量。并对新建立的旋光法与法定检验方法(HPLC-RID法)测定乳糖含量的等效性进行了研究。结果:所建立的方法在0.05~0.20 g·mL^(-1)范围内与旋光度呈良好的线性关系(r=1.0000)、重现性[RSD=0.07%(n=6)]。旋光度法测得的141批乳糖含量与法检结果比较,同批样品间相对偏差均不大于1.0%。单因素方差分析检验结果也显示,两组数据无显著性差异(Sig.>0.05)。结论:本法与《中国药典》2020年版四部中HPLC-RID法性能相当,同时,可降低测试成本,缩短测试时间,满足质量控制需求。 展开更多
关键词 乳糖含量 快速测定 旋光法 等效性研究 质量控制
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Current Status and Future Challenges of Weather Radar Polarimetry: Bridging the Gap between Radar Meteorology/Hydrology/Engineering and Numerical Weather Prediction 被引量:10
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作者 Guifu ZHANG Vivek N.MAHALE +25 位作者 Bryan J.PUTNAM Youcun QI Qing CAO ANDrew D.BYRD Petar BUKOVCIC Dusan S.ZRNIC Jidong GAO Ming XUE Youngsun JUNG Heather D.REEVES Pamela L.HEINSELMAN AlexANDer RYZHKOV Robert D.PALMER Pengfei ZHANG Mark WEBER Greg M.MCFARQUHAR Berrien MOORE III Yan ZHANG Jian ZHANG J.VIVEKANANDAN Yasser AL-RASHID Richard L.ICE Daniel S.BERKOWITZ Chong-chi TONG Caleb FULTON Richard J.DOVIAK 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第6期571-588,共18页
After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve we... After decades of research and development, the WSR-88 D(NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data(PRD) that have the potential to improve weather observations,quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction(NWP) models.In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation. 展开更多
关键词 WEATHER RADAR polarimetry RADAR METEOROLOGY numerical WEATHER prediction data ASSIMILATION MICROPHYSICS parameterization forward operator
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Crosstalk-free achromatic full Stokes imaging polarimetry metasurface enabled by polarization-dependent phase optimization 被引量:21
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作者 Yaxin Zhang Mingbo Pu +10 位作者 Jinjin Jin Xinjian Lu Yinghui Guo Jixiang Cai Fei Zhang Yingli Ha Qiong He Mingfeng Xu Xiong Li Xiaoliang Ma Xiangang Luo 《Opto-Electronic Advances》 SCIE EI CAS 2022年第11期16-28,共13页
Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths an... Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth. 展开更多
关键词 metasurface broadband achromatic crosstalk-free full polarization imaging polarimetry
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Multi-polarization reconstruction from compact polarimetry based on modified four-component scattering decomposition 被引量:1
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作者 Junjun Yin Jian Yang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2014年第3期399-410,共12页
An improved algorithm for multi-polarization reconstruction from compact polarimetry (CP) is proposed. According to two fundamental assumptions in compact polarimetric reconstruction, two improvements are proposed. ... An improved algorithm for multi-polarization reconstruction from compact polarimetry (CP) is proposed. According to two fundamental assumptions in compact polarimetric reconstruction, two improvements are proposed. Firstly, the four-component model-based decomposition algorithm is modified with a new volume scattering model. The decomposed helix scattering component is then used to deal with the non-reflection symmetry condition in compact polarimetric measurements. Using the decomposed power and considering the scattering mechanism of each component, an average relationship between copolarized and crosspolarized channels is developed over the original polarization state extrapolation model. E-SAR polarimetric data acquired over the Oberpfaffenhofen area and JPL/AIRSAR polarimetric data acquired over San Francisco are used for verification, and good reconstruction results are obtained, demonstrating the effectiveness of the proposed algorithm. 展开更多
关键词 polarimetric synthetic aperture radar (SAR) target decomposition compact polarimetry (CP) multi-polarization reconstruction.
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Polarimetry feature parameter deriving from Mueller matrix imaging and auto-diagnostic signicance to distinguish HSIL and CSCC 被引量:1
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作者 Anli Hou Xingjian Wang +5 位作者 Yujuan Fan Wenbin Miao Yang Dong Xuewu Tian Jibin Zou Hui Ma 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2022年第1期17-28,共12页
High-grade squamous intraepithelial lesion(HSIL)is regarded as a serious precancerous state of cervix,and it is easy to progress into cervical invasive carcinoma which highlights the importance of earlier diagnosis an... High-grade squamous intraepithelial lesion(HSIL)is regarded as a serious precancerous state of cervix,and it is easy to progress into cervical invasive carcinoma which highlights the importance of earlier diagnosis and treatment of cervical lesions.Pathologists examine the biopsied cervical epithelial tissue through a microscope.The pathological examination will take a long time and sometimes results in high inter-and intra-observer variability in outcomes.Polarization imaging techniques have broad application prospects for biomedical diagnosis such as breast,liver,colon,thyroid and so on.In our team,we have derived polarimetry feature parameters(PFPs)to characterize microstructural features in histological sections of breast tissues,and the accuracy for PFPs ranges from 0.82 to 0.91.Therefore,the aim of this paper is to distinguish automatically microstructural features between HSIL and cervical squamous cell carcinoma(CSCC)by means of polarization imaging techniques,and try to provide quantitative reference index for patho-logical diagnosis which can alleviate the workload of pathologists.Polarization images of the H&E stained histological slices were obtained by Mueller matrix microscope.The typical path-ological structure area was labeled by two experienced pathologists.Calculate the polarimetry basis parameter(PBP)statistics for this region.The PBP statistics(stat PBPs)are screened by mutual information(MI)method.The training method is based on a linear discriminant analysis(LDA)classier whichnds the most simplied linear combination from these stat PBPs and the accuracy remains constant to characterize the specic microstructural feature quantitatively in cervical squamous epithelium.We present results from 37 clinical patients with analysis regions of cervical squamous epithelium.The accuracy of PFP for recognizing HSIL and CSCC was 83.8%and 87.5%,respectively.This work demonstrates the ability of PFP to quantitatively charac-terize the cervical squamous epithelial lesions in the H&E pathological sections.Signicance:Polarization detection technology provides an effcient method for digital pathological diagnosis and points out a new way for automatic screening of pathological sections. 展开更多
关键词 polarimetry basis parameter(PBP) polarimetry feature parameter(PFP) linear discriminant analysis(LDA) mutual information(MI) high-grade squamous intraepithelial le-sion(HSIL) cervical squamous cell carcinoma(CSCC).
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Assessment of C-band compact polarimetry SAR for sea ice classification 被引量:3
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作者 ZHANG Xi ZHANG Jie +1 位作者 LIU Meijie MENG Junmin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第5期79-88,共10页
The C-band synthetic aperture radar(SAR) data from the Bohai Sea of China, the Labrador Sea in the Arctic and the Weddell Sea in the Antarctic are used to analyze and discuss the sea ice full polarimetric informatio... The C-band synthetic aperture radar(SAR) data from the Bohai Sea of China, the Labrador Sea in the Arctic and the Weddell Sea in the Antarctic are used to analyze and discuss the sea ice full polarimetric information reconstruction ability under compact polarimetric modes. The type of compact polarimetric mode which has the highest reconstructed accuracy is analyzed, along with the performance impact of the reconstructed pseudo quad-pol SAR data on the sea ice detection and sea ice classification. According to the assessment and analysis, it is recommended to adopt the CTLR mode for reconstructing the polarimetric parameters σ_(HH)~0,σ_(VV)~0, H and α,while for reconstructing the polarimetric parameters σ_(HV)~0, ρ_(H-V), λ_1 and λ_2, it is recommended to use the π/4 mode.Moreover, it is recommended to use the π/4 mode in studying the action effects between the electromagnetic waves and sea ice, but it is recommended to use the CTLR mode for studying the sea ice classification. 展开更多
关键词 sea ice SAR compact polarimetry sea ice classification assessment and analysis
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The Study of Retinal Nerve Fiber Layer Thickness of Normal Eyes Using Scanning Laser Polarimetry 被引量:2
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作者 Xing Liu Jingjing Huang Jian Ge Yunlan Ling Xiaoping Zheng 《眼科学报》 2006年第3期175-183,共9页
Purpoe: To evaluate retinal nerve fiber layer (RNFL) thickness measurements in local normal Chinese subjects of different age groups and analyse the correlation of RNFL thickness with age using scanning laser polarime... Purpoe: To evaluate retinal nerve fiber layer (RNFL) thickness measurements in local normal Chinese subjects of different age groups and analyse the correlation of RNFL thickness with age using scanning laser polarimetry (SLP,GDxVCC). To assess the reproducibility of RNFL thickness measurement with GDxVCC. Methods: The RNFL thickness of 67 normal subjects (123 eyes) were measured by GDxVCC. The average TSNIT parameters were calculated. The differences of RNFL thickness between sex,right and left eyes,superior and inferior were compared. The relationship between RNFL thickness and age was analyzed with correlation analysis and linear regression analysis. The intraclass correlation coefficients (ICC) of three images in every eye were calculated. Results: The average peripapillary RNFL thickness at the superior,inferior and whole ellipse regions in 123 eyes of 67 normal subjects were (70.30±6.76)(?)m,(67.35±6.77)(?)m and (56.87±4.53)(?) m,respectively. The average TNSIT standard deviation was 23.68±4.61 and the average inter-eye symmetric value was 0.86±0.11. There were significant difference of RNFL thickness between superior and inferior (t=4.952,P < 0.001). There were significant difference of inferior RNFL thickness and TNSIT standard deviation between right and left eyes (P=0.005 and 0.002),while not significant difference of superior RNFL thickness and whole mean RNFL thickness between right and left eye (P=0.086 and 0.529). There was no significant difference in TSNIT parameters between different genders. There was a slight negative correlation average RNFL thickness in superior sector with age (decreased approximately 0.15 microns per year,P=0.047) in the subjects aged below 60 years old. The ICC values of RNFL thickness were >0.8 in superior,inferior and global. Conclusions: The RNFL thickness can be measured accurately by GDxVCC and the reproducibility of RNFL thickness measurement by GDxVCC is good. There was a slight negative correlation between average RNFL thickness in superior with age. More researches on the effects of age on RNFL thickness by GDxVCC are needed. 展开更多
关键词 Scanning laser polarimetry Retinal nerve fiber layer Normal subjects
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基于全偏振成像和机器学习的肝细胞癌与肝内胆管癌鉴别诊断研究
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作者 林丽燕 董佳 +5 位作者 肖伟进 彭然 吴方君 马辉 力超 刘景丰 《临床外科杂志》 2023年第2期164-167,共4页
目的探讨全偏振成像和机器学习在肝细胞癌与肝内胆管癌鉴别诊断中的作用。方法利用全偏振显微镜对术后经病理确诊为低分化肝细胞癌和低分化肝内胆管癌病例各8例进行偏振成像;病理医生根据HE切片选取3块感兴趣区域,测量每块区域的穆勒矩... 目的探讨全偏振成像和机器学习在肝细胞癌与肝内胆管癌鉴别诊断中的作用。方法利用全偏振显微镜对术后经病理确诊为低分化肝细胞癌和低分化肝内胆管癌病例各8例进行偏振成像;病理医生根据HE切片选取3块感兴趣区域,测量每块区域的穆勒矩阵,并根据穆勒矩阵参数提取分析方法计算出一系列的偏振基准参数;将偏振特征参数输入到人工神经网络模型中,采用了8折交叉验证方法对模型进行三分类的训练和验证。结果模型结果显示,基于图像偏振特征区分肝细胞癌、肝内胆管癌与除了癌变细胞以外的其他组织的准确率为0.8463,灵敏度为0.8107。结论基于全偏振成像和机器学习构建的肝细胞癌和肝内胆管癌诊断模型具有重要的病理辅助诊断价值。 展开更多
关键词 肝细胞癌 肝内胆管癌 全偏振成像 人工神经网络
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2.16 m望远镜偏振光度计 被引量:1
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作者 邱鹏 王国聪 +4 位作者 张晓明 张茗璇 赵勇 王建峰 姜晓军 《红外与激光工程》 EI CSCD 北大核心 2023年第7期212-225,共14页
为了使2.16 m望远镜具备线偏振测光观测能力,开展了偏振光度计研制。该系统采用双通道分时偏振成像方案,具有偏振定标单元、偏振测量单元,可实现偏振定标、偏振测量和多色测光。完成系统研制后,将其安装在2.16 m望远镜上开展实测,依照... 为了使2.16 m望远镜具备线偏振测光观测能力,开展了偏振光度计研制。该系统采用双通道分时偏振成像方案,具有偏振定标单元、偏振测量单元,可实现偏振定标、偏振测量和多色测光。完成系统研制后,将其安装在2.16 m望远镜上开展实测,依照该偏振光度计偏振观测流程拍摄了一系列非偏振标准星、偏振标准星、流量标准星;按照偏振定标和偏振态解算数据处理方法,对获取图像进行数据处理。结果显示:该偏振光度计视场为4.63′×4.63′,像元比例尺为0.54(″)/pixel,偏振度测量精度优于0.01,60 s曝光时间可以拍摄到V波段信噪比约为141的15.3等星。该偏振光度计使2.16 m望远镜具备V波段线偏振测光和快速多色测光观测能力。 展开更多
关键词 成像偏振测量 偏振测光 线偏振测光 天文测光
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一种基于频域解模糊的星载P波段全极化SAR法拉第旋转效应校正方法 被引量:2
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作者 张永胜 于春锐 +5 位作者 计一飞 董臻 张启雷 于雷 甘楠 姚柏栋 《电子学报》 EI CAS CSCD 北大核心 2023年第3期585-592,共8页
星载P波段合成孔径雷达(Synthetic Aperture Radar,SAR)极化测量性能易受电离层法拉第旋转(Faraday Rotation,FR)效应的影响,随着系统带宽增加,以及中心频率对应的法拉第旋转角(FR Angle,FRA)增大,FR效应色散特征突显,将导致距离向成像... 星载P波段合成孔径雷达(Synthetic Aperture Radar,SAR)极化测量性能易受电离层法拉第旋转(Faraday Rotation,FR)效应的影响,随着系统带宽增加,以及中心频率对应的法拉第旋转角(FR Angle,FRA)增大,FR效应色散特征突显,将导致距离向成像恶化以及额外的极化测量误差.针对色散FR效应,提出了一种基于频域解模糊的星载P波段全极化SAR法拉第旋转效应校正方法,通过模糊度一致化以及频域拟合等关键步骤,解决了P波段SAR系统FRA估计值模糊问题,最后在频域实现色散FR效应的校正.利用机载P波段全极化SAR数据开展了仿真验证实验,与传统的图像域校正方法相比,有效抑制了色散的FR效应,显著改善了交叉极化通道图像之间的相关性. 展开更多
关键词 星载SAR P波段 极化测量 电离层 法拉第旋转 色散
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Identification of serous ovarian tumors based on polarization imaging and correlation analysis with clinicopathological features
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作者 Yulu Huang Anli Hou +7 位作者 Jing Wang Yue Yao Wenbin Miao Xuewu Tian Jiawen Yu Cheng Li Hui Ma Yujuan Fan 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2023年第5期33-46,共14页
Ovarian cancer is one of the most aggressive and heterogeneous female tumors in the world,and serous ovarian cancer(SOC)is of particular concern for being the leading cause of ovarian cancer death.Due to its clinical ... Ovarian cancer is one of the most aggressive and heterogeneous female tumors in the world,and serous ovarian cancer(SOC)is of particular concern for being the leading cause of ovarian cancer death.Due to its clinical and biological complexities,ovarian cancer is still considered one of the most di±cult tumors to diagnose and manage.In this study,three datasets were assembled,including 30 cases of serous cystadenoma(SCA),30 cases of serous borderline tumor(SBT),and 45 cases of serous adenocarcinoma(SAC).Mueller matrix microscopy is used to obtain the polarimetry basis parameters(PBPs)of each case,combined with a machine learning(ML)model to derive the polarimetry feature parameters(PFPs)for distinguishing serous ovarian tumor(SOT).The correlation between the mean values of PBPs and the clinicopathological features of serous ovarian cancer was analyzed.The accuracies of PFPs obtained from three types of SOT for identifying dichotomous groups(SCA versus SAC,SCA versus SBT,and SBT versus SAC)were 0.91,0.92,and 0.8,respectively.The accuracy of PFP for identifying triadic groups(SCA versus SBT versus SAC)was 0.75.Correlation analysis between PBPs and the clinicopathological features of SOC was performed.There were correlations between some PBPs(δ,β,q_(L),E_(2),rqcross,P_(2),P_(3),P_(4),and P_(5))and clinicopathological features,including the International Federation of Gynecology and Obstetrics(FIGO)stage,pathological grading,preoperative ascites,malignant ascites,and peritoneal implantation.The research showed that PFPs extracted from polarization images have potential applications in quantitatively differentiating the SOTs.These polarimetry basis parameters related to the clinicopathological features of SOC can be used as prognostic factors. 展开更多
关键词 Serous ovarian tumor(SOT) polarimetry basis parameter(PBP) polarimetry feature parameter(PFP) polarization imaging machine learning(ML).
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Establishment and study of a polarized X-ray radiation facility
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作者 Xing Zhou Xiao-Yu Qie +7 位作者 Si-Ming Guo Yong-Bo Huang Zi-Yao Shu Shi-Kui Huang Li-Peng Fan Kai-Yue Guo Tao Yu Jin-Jie Wu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第8期54-63,共10页
With the advancement in X-ray astronomical detection technology,various celestial polarization detection projects have been initiated.To meet the calibration requirements of polarimeters on the ground,a polarized X-ra... With the advancement in X-ray astronomical detection technology,various celestial polarization detection projects have been initiated.To meet the calibration requirements of polarimeters on the ground,a polarized X-ray radiation facility was designed for this study.The design was based on the principle that X-rays incident at 45°on a crystal produce polarized X-rays,and a second crystal was used to measure the polarization of the X-rays produced by the facility after rotation.The effects of different diaphragm sizes on the degree of polarization were compared,and the facility produced X-rays with polarization degrees of up to 99.55±0.96%using LiF200 and LiF220 crystals.This result revealed that the polarization of incident X-rays is one of the factors affecting the diffraction efficiency of crystals.The replacement of different crystals can satisfy the calibration requirements of polarized X-ray detectors with more energy points in the energy range(4-10)keV.In the future,the facility should be placed in a vacuum environment to meet the calibration requirements at lower energies. 展开更多
关键词 Polarized X-rays polarimetry CALIBRATION Bragg diffraction
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Depolarizing metrics in the biomedical field:Vision enhancement and classification of biological tissues
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作者 Mónica Canabal-Carbia Albert Van Eeckhout +7 位作者 Carla Rodríguez Emilio González-Arnay Irene Estévez JoséJ.Gil Enrique García-Caurel Razvigor Ossikovski Juan Campos Angel Lizana 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2023年第5期3-19,共17页
Polarimetry encompasses a collection of optical techniques broadly used in a variety of fields.Nowadays,such techniques have provided their suitability in the biomedical field through the study of the polarimetric res... Polarimetry encompasses a collection of optical techniques broadly used in a variety of fields.Nowadays,such techniques have provided their suitability in the biomedical field through the study of the polarimetric response of biological samples(retardance,dichroism and depolarization)by measuring certain polarimetric observables.One of these features,depolarization,is mainly produced by scattering on samples,which is a predominant efiect in turbid media as biological tissues.In turn,retardance and dichroic efiects are produced by tissue anisotropies and can lead to depolarization too.Since depolarization is a predominant efiect in tissue samples,we focus on studying difierent depolarization metrics for biomedical applications.We report the suitability of a set of depolarizing observables,the indices of polarimetric purity(IPPs),for biological tissue inspection.We review some results where we demonstrate that IPPs lead to better performance than the depolarization index,which is a well-established and commonly used depolarization observable in the literature.We also provide how IPPs are able to significantly enhance contrast between difierent tissue structures and even to reveal structures hidden by using standard intensity images.Finally,we also explore the classificatory potential of IPPs and other depolarizing observables for the discrimination of difierent tissues obtained from ex vivo chicken samples(muscle,tendon,myotendinous junction and bone),reaching accurate models for tissue classification. 展开更多
关键词 polarimetry indices of polarimetric purity organic tissues visualization artificial intelligence.
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