“天琴计划”教育部重点实验室,天琴中心 & 物理与天文学院,天琴前沿科学中心,国家航天局引力波研究中心,中山大学(珠海校区),广东 珠海 519082
Overview: The space gravitational wave detection telescope is one of the core payloads of the gravitational wave detection satellite, simultaneously expanding and contracting the transmitted beam. Optical path stability is one of the core indices for the telescope, closely related to its structural stability. To meet the ultra-high path stability and structural stability requirements posed by the gravitational wave detection mission, it is essential to study the structural deformation measurement of the telescope. Currently, there are still several shortcomings in the research of multi-degree-of-freedom deformation measurement methods for gravitational wave detection telescopes, such as inaccurate selection of measurement points, inability to decouple multi-degree-of-freedom coupling, and unclear identification of error sources in multi-degree-of-freedom measurement. This paper deeply investigates the high-precision measurement of structural deformation of space-borne telescopes designed for space gravitational wave detection. It preliminarily establishes a framework and method system for measuring the structural deformation of space-borne telescopes, theoretically describing the measurement principle of the method. The feasibility of this method applied to space gravitational wave detection is verified through simulation analysis and error decomposition. The paper focuses on resolving the issue of decoupling multiple degrees of freedom, establishing a mathematical model using analytical methods, and conducting preliminary validation using Zemax. Finally, noise analysis of the measurement system is carried out, with experimental testing of the main noise components in the measurement system, validating the correctness of the theoretical noise model proposed in this paper. The experimental results show that near 1 Hz, the displacement noise background of the single-link interferometer is 100 pm/Hz1/2. At 1 mHz in the low-frequency range, the displacement noise background reaches 10 nm/Hz1/2. The noise level of the measurement system below 1 mHz is mainly limited by environmental temperature noise, while above 10 mHz, it is primarily constrained by laser frequency noise, phase acquisition background noise, and vibration noise. During the development phase of the space gravitational wave detection telescope, the research on this measurement method is expected to fulfill the telescope's multi-degree-of-freedom deformation measurement needs. It also provides data feedback for telescope design and offers guidance for the study of the telescope's optical path stability.
空间引力波探测望远镜 形变测量 多自由度 解耦研究 噪声分析 the space gravitational wave detection telescope deformation measurement multi-degree-of-freedom decoupling study noise analysis
1 中国科学技术大学生命科学与医学部生物医学工程学院,江苏 苏州 215163
2 中国科学院苏州生物医学工程技术研究所,江苏 苏州 215163
3 东南大学附属中大医院消化内科,江苏 南京 210009
食管鳞癌(ESCC)是我国常见的消化道恶性肿瘤之一。临床上,窄带成像联合放大内镜(NBI-ME)能够显示出食管粘膜层的微血管形态变化,是诊断ESCC的重要手段。针对ESCC识别模型难以兼顾识别准确率和推理效率的问题,提出一种融合注意力机制的轻量化残差网络(CALite-ResNet)对食管NBI-ME图像进行分类。从多家医院采集到206例患者共11468张NBI-ME图像作为本研究数据集。实验结果表明,ESCC识别的准确率和敏感度分别在图像级别达到96.39%和95.70%,在病人级别达到95.70%和94.62%,单张食管图像的平均预测时间为16.42 ms。因此,CALite-ResNet模型对ESCC具有较高的识别准确率和较快的推理效率,能够为ESCC的临床辅助诊断提供有效帮助,具备一定的临床意义与应用价值。
图像处理 轻量化网络 注意力机制 食管鳞癌 窄带成像 放大内镜 激光与光电子学进展
2023, 60(10): 1010023
Author Affiliations
Abstract
1 School of Physics, Harbin Institute of Technology, Harbin 150001, China
2 School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
3 Department of Physics, Fuzhou University, Fuzhou 350002, China
The prevalent fashion of executing Rydberg-mediated two- and multi-qubit quantum gates in neutral atomic systems is to pump Rydberg excitations using multistep piecewise pulses in the Rydberg blockade regime. Here, we propose to synthesize a -type Rydberg antiblockade (RAB) of two neutral atoms using periodic fields, which facilitates one-step implementations of SWAP and controlled-SWAP (CSWAP) gates with the same gate time. Besides, the RAB condition is modified so as to circumvent the sensitivity of RAB-based gates to infidelity factors, including atomic decay, motional dephasing, and interatomic distance deviation. Our work makes up the absence of one-step schemes of Rydberg-mediated SWAP and CSWAP gates and may pave a way to enhance the robustness of RAB-based gates.
Photonics Research
2021, 9(5): 05000814
Author Affiliations
Abstract
1 Department of Photonics & Graduate Institute of Electro-Optical Engineering, College of Electrical and Computer Engineering, Taiwan Chiao Tung University, Hsinchu 30010, China
2 Institute of Photonic System, Taiwan Chiao Tung University, Tainan 71150, China
3 Saphlux Inc., Branford, Connecticut 06405, USA
4 Department of Electronic Science, Fujian Engineering Research Center for Solid-State Lighting, Xiamen University, Xiamen 361005, China
5 Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520, USA
6 e-mail: wutingzhu@xmu.edu.cn
7 e-mail: hckuo@faculty.nctu.edu.tw
Red-green-blue (RGB) full-color micro light-emitting diodes (μ-LEDs) fabricated from semipolar (20-21) wafers, with a quantum-dot photoresist color-conversion layer, were demonstrated. The semipolar (20-21) InGaN/GaN μ-LEDs were fabricated on large (4 in.) patterned sapphire substrates by orientation-controlled epitaxy. The semipolar μ-LEDs showed a 3.2 nm peak wavelength shift and a 14.7% efficiency droop under injected current density, indicating significant amelioration of the quantum-confined Stark effect. Because of the semipolar μ-LEDs’ emission-wavelength stability, the RGB pixel showed little color shift with current density and achieved a wide color gamut (114.4% NTSC space and 85.4% Rec. 2020).
Photonics Research
2020, 8(5): 05000630
海军航空大学信息融合所, 山东 烟台 264001
通过研究入射余角44°~69°的海杂波实测数据的时间相关特性、空间相关性及幅度统计特性发现,海杂波相关时间维持在毫秒量级, 且随着入射余角增加, 先增加后减小, 时间相关性最强的入射余角在60°左右, 而平均相关距离单元个数一直增加。针对大入射余角高分辨率海杂波的幅度统计特性提出一种新的海杂波幅度拟合混合分布, 并通过KK分布、Rayleigh分布、对数正态分布及K分布的对比, 证明了新的混合分布对大入射余角海杂波的拖尾部分具有良好的拟合效果。
海杂波 幅度统计特征 大入射余角 混合分布 时间相关性 空间相关性 sea clutter amplitude statistics large grazing angle mixed distribution temporal correlation spatial correlation
檀贯妮 1,2,3,4,*高宏 1,2,3,4,5宋杰 6商士斌 1,2,3,4,5宋湛谦 1,2,3,4,5
1 中国林业科学研究院林产化学工业研究所
2 生物质化学利用国家工程实验室
3 国家林业局林产化学工程 重点开放性实验室
4 江苏省生物质能源与材料重点实验室, 江苏 南京 210042
5 中国林业科学研究院林业新技术研究所, 北京 100091
6 Department of Chemistry and Biochemistry, University of Michigan-Flint, Flint, MI 48502, USA
对三苯胺进行溴代和C-N偶联反应合成4-萘基三苯胺(a), 对脱氢枞酸进行酯化、 溴代、 硝化、 还原和C-N偶联反应合成13-[N,N-(4-萘基苯基)-苯基]胺基-脱异丙基脱氢枞酸甲酯(b)及13-[N,N-双(4-萘基苯基)]胺基-脱异丙基脱氢枞酸甲酯(c)两个化合物, 通过1H MNR, 13C MNR及MS对化合物的结构进行表征。 为了研究化合物结构与光谱性能之间的关系, 首先利用Gaussian 09程序采用密度泛函DFT/B3LYP方法, 对三个化合物的空间构型进行全优化, 得到它们的键长、 键角和二面角, 对比发现脱氢枞酸骨架和萘环的引入会影响化合物的共平面性, 而萘环的引入会增大化合物的共轭程度。 光谱性能方面, 研究了三种化合物在甲醇、 二氧六环、 四氢呋喃、 二氯甲烷和环己烷这5种极性逐渐减小的溶剂中的荧光发射光谱和紫外吸收光谱。 结果表明, 在荧光光谱中, 化合物a, b和c在不同极性溶剂中最大荧光发射波长均有不同程度位移, 在甲醇中最大, 在环己烷中最小, 但是位移并非随着极性的增大而只发生红移, 在二氯甲烷、 四氢呋喃和二氧六环3种极性依次增大的溶剂中, a, b, c的荧光发射波长均随着溶剂极性的增大而发生较大程度的蓝移; 在同一溶剂中, 化合物b和c相对于a的荧光发射波长依次发生红移, c的红移程度与b差距不大。 紫外吸收光谱中, 三个化合物在不同极性溶剂中的最大吸收波长也有差异, 在200~250 nm区间, 三个化合物均在二氯甲烷中有较大位移, 在300~350 nm区间, 在甲醇中位移较大, 而在250~300 nm区间, 最大吸收波长差别不大; 在同一溶剂中, 它们在300~350 nm区间的最大吸收波长差别较大, 化合物c较a红移26 nm。 结合结构优化所得数据可以证明, 化合物的共轭程度对荧光发射光谱和紫外吸收光谱均有影响, 而共平面性对荧光发射光谱影响较大。 化合物a, b和c在不同极性溶剂中荧光发射光谱和紫外吸收光谱的较大变化, 表明它们有明显的溶致变色行为, 具有作为分子探针探测外部环境极性大小的潜能。
脱氢枞酸三芳胺 D-A结构 合成 空间构型 光谱性能 Dehydroabietic acid-based triarylamine D-A structure Synthesis Spatial configuration Spectral property 光谱学与光谱分析
2019, 39(7): 2083
1 太原理工大学 物理与光电工程学院, 山西 太原 030006
2 韩山师范学院 材料科学与工程学院, 广东 潮州 521041
采用甚高频等离子体增强化学气相沉积技术, 以SiH4、CH4和O2作为反应气源, 通过调控O2流量在250 ℃下制备强光发射的非晶SiCxOy薄膜。利用光致发光光谱、荧光瞬态谱、Raman光谱、X射线光电子能谱及红外吸收谱对薄膜的光学性质和微结构进行表征与分析, 进而讨论其可调可见光发射机制。实验结果表明, SiCxOy薄膜发光性质与薄膜中的氧组分密切相关。随着薄膜中氧组分的增加, 其发光峰位由橙红光逐渐向蓝光移动, 肉眼可见强的可见光发射。荧光瞬态谱分析表明,薄膜的荧光寿命在纳秒范围。结合X射线光电子能谱和红外吸收谱对薄膜的相结构和化学键合结构进行分析, 结果表明薄膜的主要相结构和发光中心随O2流量的变化是其可调光发射的主要原因。
光致发光 碳氧化硅 等离子增强化学气相沉积 发光机制 photoluminescence silicon oxycarbide plasma enhance chemical vapor deposition photoluminescence mechanism
1 太原理工大学 物理与光电工程学院, 山西 太原030006
2 韩山师范学院 材料科学与工程学院, 广东 潮州521041
利用磁控溅射技术在低温250 ℃下制备Eu掺杂SiCxOy薄膜, 研究薄膜的Eu3+发光激发机制。实验结果表明, 薄膜的发光谱由来自基体材料的蓝光和来自Eu3+的红光组成; 随着薄膜中Eu含量由0.19%增加到2.27%, 其红光强度增加3倍左右, 而蓝光逐渐减弱。Raman光谱及荧光瞬态谱分析表明, 其蓝光由中立氧空位缺陷发光中心引起。结合薄膜的Eu3+激发光谱分析, SiCxOy∶Eu薄膜的红光增强源于薄膜中Eu3+离子浓度的增加和/或基体材料的中立氧空位缺陷发光中心与Eu3+离子的能量转移。
光致发光 铕掺杂 碳氧化硅 能量转移 photoluminescence europium dopant silicon oxycarbide energy transfer