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Electrical Detection of Shale Gas Layers Based on Wide-Field Electromagnetic Method
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作者 Man Li-Xin Tan Zhang-Kun +3 位作者 Jia Jian-Chao Gu Zhi-Wen Yu Chang-Heng Yin Xue-Bo 《Applied Geophysics》 2025年第3期878-890,898,共14页
The drilling gas production situation indicates a certain correlation between the shale gas reservoir in the Sichuan Basin and the high and low changes in formation resistivity.These variations are observed in the fir... The drilling gas production situation indicates a certain correlation between the shale gas reservoir in the Sichuan Basin and the high and low changes in formation resistivity.These variations are observed in the first member of the Longmaxi Formation to the Wufeng Formation at the bottom of the Longmaxi Formation.Given this correlation and based on the logging electrical data,this study employs the wide-field electromagnetic method(WFEM)to experimentally detect the electrical characteristics of the deep shale gas target layer in the Yibin area of southern Sichuan.The study also tests the regularity and effectiveness of the electrical parameters for evaluating favorable areas of shale gas reservoirs.In terms of specific operation,the structural pattern of the study area is implemented based on the wide-field electromagnetic results and geological data for comprehensive analysis,which identifies the main hidden faults and their influence range on low resistance.The detailed spatial distribution of the upper Ordovician Wufeng Formation and the lower Silurian Longmaxi Formation in the target layer with a buried depth of 2000-5000m is described.This layer exhibits the characteristics of a continuous and stable distribution of organic shale.After verifying the subsequent electrical logging data,the electrical logging curve is found to be essentially consistent with the shape and trend of the wide-field resistivity curve.This consistency demonstrates the effectiveness of WFEM in detecting shale gas layers. 展开更多
关键词 wide-field electromagnetic method feasibility study Shale gas exploration Recognition accuracy structural pattern
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Application of a wide-field electromagnetic method to shale gas exploration in South China 被引量:7
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作者 杨学立 李博 +1 位作者 彭传圣 杨洋 《Applied Geophysics》 SCIE CSCD 2017年第3期441-448,462,共9页
In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method (WFEM), because of its strong anti-interference capability, high resolution, ability to conduct expl... In an effort to reduce the shale gas exploration risks and costs, we applied the wide-field electromagnetic method (WFEM), because of its strong anti-interference capability, high resolution, ability to conduct exploration at large depths, and high efficiency, to the Bayan Syncline in the South Huayuan block, Hunan Province. We collected rock samples and analyzed their resistivity and induced polarization (IP) and built A series of two-dimensional models for geological conditions to investigate the applicability of WFEM to different geological structures. We also analyzed the correlation between TOC of shale and the resistivity and IP ratio to determine the threshold for identifying target formations. We used WFEM to identify the underground structures and determine the distribution, depth, and thickness of the target strata. Resistivity, IP, and total organic carbon were used to evaluate the shale gas prospects and select favorable areas (sweet spots) for exploration and development. Subsequently, drilling in these areas proved the applicability of WFEM in shale gas exploration. 展开更多
关键词 wide-field electromagnetic method shale gas RESISTIVITY induced polarization total organic carbon
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Extracting useful high-frequency information from wide-field electromagnetic data using time-domain signal reconstruction 被引量:1
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作者 LING Fan YANG Yang +6 位作者 LI Gang ZHOU Chang-yu HUANG Min WANG Xin ZHANG Heng ZHU Yu-zhen SUN Huai-feng 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第11期3767-3778,共12页
The wide-field electromagnetic method is widely used in hydrocarbon exploration,mineral deposit detection,and geological disaster prediction.However,apparent resistivity and normalized field amplitude exceeding 2048 H... The wide-field electromagnetic method is widely used in hydrocarbon exploration,mineral deposit detection,and geological disaster prediction.However,apparent resistivity and normalized field amplitude exceeding 2048 Hz often exhibit upward warping in data,making geophysical inversion and interpretation challenging.The cumulative error of the crystal oscillator in signal transmission and acquisition contributes to an upturned apparent resistivity curve.To address this,a high-frequency information extraction method is proposed based on time-domain signal reconstruction,which helps to record a complete current data sequence;moreover,it helps estimate the crystal oscillator error for the transmitted signal.Considering the recorded error,a received signal was corrected using a set of reconstruction algorithms.After processing,the high-frequency component of the wide-field electromagnetic data was not upturned,while accurate high-frequency information was extracted from the signal.Therefore,the proposed method helped effectively extract high-frequency components of all wide-field electromagnetic data. 展开更多
关键词 wide-field electromagnetic method crystal oscillator error time series signal resampling signal reconstruction
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Non-contact wide-field viewing system-assisted scleral buckling surgery for retinal detachment in silicone oilfilled eyes 被引量:1
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作者 Su-Lan Wu Yi-Qi Chen +7 位作者 Li-Jun Shen Jian-Bo Mao Li Lin Ji-Wei Tao Huan Chen Shi-An Zhang Jia-Feng Yu Chen-Xi Wang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第4期761-766,共6页
AIM:To evaluate scleral buckling(SB)surgery using a noncontact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil(SO)-filled eyes.MET... AIM:To evaluate scleral buckling(SB)surgery using a noncontact wide-field viewing system and 23-gauge intraocular illumination for the treatment of rhegmatogenous retinal detachment in silicone oil(SO)-filled eyes.METHODS:Totally 9 patients(9 eyes)with retinal detachment in SO-filled eyes were retrospectively analyzed.All patients underwent non-contact wide-field viewing system-assisted buckling surgery with 23-gauge intraocular illumination.SO was removed at an appropriate time based on recovery.The patients were followed up for at least 3mo after SO removal.Retinal reattachment,complications,visual acuity and intraocular pressure(IOP)before and after surgery were observed.RESULTS:Patients were followed up for a mean of 8.22mo(3-22mo)after SO removal.All patients had retinal reattachment.At the final follow-up,visual acuity showed improvement for 8 patients,and no change for 1 patient.The IOP was high in 3 patients before surgery,but it stabilized after treatment;it was not affected in the other patients.None of the patients had infections,hemorrhage,anterior ischemia,or any other complication.CONCLUSION:This new non-contact wide-field viewing system-assisted SB surgery with 23-gauge intraocular illumination is effective and safe for retinal detachment in SO-filled eyes. 展开更多
关键词 non-contact wide-field viewing system scleral buckling silicone oil-filled retinal detachment
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Combined Application of Wide-Field Electromagnetic Method and Flow Field Fitting Method for High-Resolution Exploration: A Case Study of the Anjialing No. 1 Coal Mine 被引量:22
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作者 Jishan He 《Engineering》 2018年第5期667-675,共9页
The Anjialing No. 1 Coal Mine in Shanxi Province, China, contains a complicated old goaf and an unknown water distribution that hold high potential for serious water hazards. Due to poor detection resolution, previous... The Anjialing No. 1 Coal Mine in Shanxi Province, China, contains a complicated old goaf and an unknown water distribution that hold high potential for serious water hazards. Due to poor detection resolution, previous attempts have failed to determine the scope of the old goal and the water distribution in the mine by separate use of various exploration methods such as seismic method, direct current resistivity, audio magnetotellurics, controlled-source audio-frequency magnetotellurics, and transient electromag-netics. To solve this difficult problem, a combination of the wide-field electromagnetic method and the flow field fitting method with three-dimensional resistivity data inversion was applied to determine the precise scope of the goal and the locations where water is present, and to identify the hydraulic con- nection between the water layers so as to provide reliable technical support for safe coal production. Reasonable results were achieved, with all these goals being met. As a result, a mining area of nearly 4 km^2 has been released for operation. 展开更多
关键词 wide-field electromagnetic method Flow field fitting method GoalWater abundance High-resolution exploration
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Wide-Field Vibrational Phase Contrast Imaging Based on Coherent Anti-Stokes Raman Scattering Holography 被引量:1
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作者 吕永钢 纪子衡 +2 位作者 董大山 施可彬 龚旗煌 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第7期86-89,共4页
We propose and implement a wide-field vibrational phase contrast detection to obtain imaging of imaginary components of third-order nonlinear susceptibility in a coherent anti-Stokes Raman scattering (CARS) microsco... We propose and implement a wide-field vibrational phase contrast detection to obtain imaging of imaginary components of third-order nonlinear susceptibility in a coherent anti-Stokes Raman scattering (CARS) microscope with full suppression of the non-resonant background. This technique is based on the unique ability of recovering the phase of the generated CARS signal based on holographic recording. By capturing the phase distributions of the generated CARS field from the sample and from the environment under resonant illumination, we demonstrate the retrieval of imaginary components in the CARS microscope and achieve background free coherent Raman imaging. 展开更多
关键词 wide-field Vibrational Phase Contrast Imaging Based on Coherent Anti-Stokes Raman Scattering Holography
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Application of wide-field electromagnetic method for favorable target optimization in the Heishan granite geothermal area of Yunnan Province 被引量:1
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作者 Jie Li Honghu Zeng +2 位作者 Xiaoyong Lu Chao Xu Jingrui Chen 《Natural Gas Industry B》 2024年第1期74-82,共9页
The Heishan geothermal area is positioned above the sole Yunnane-Tibet high-temperature geothermal belt,where huge geothermal energy resources are available.Utilizing the characteristics of large exploration depth,ext... The Heishan geothermal area is positioned above the sole Yunnane-Tibet high-temperature geothermal belt,where huge geothermal energy resources are available.Utilizing the characteristics of large exploration depth,extensive coverage,and high precision of the wide-field elec-tromagnetic method,four survey lines were deployed,totaling 29.8 km,to enable a comprehensive analysis of the granite structure and fault distribution.The results indicate that the rocks within the area can be vertically divided into a granite basement and a fractured layer.Moreover,three different zones of resistivity were identified:the granite basement zone has a resistivity range of 2500-20000 U m,whereas the compressional shear zone and the secondary fault zone have a resistivity range of 750-2500 U m,and the extensional fault zone and the main fault zone have resistivity values below 750 U m.The Heishan-Hejian fault and the fault zone formed during its right-lateral strike-slip process,as well as the controlled area of the Qianmaihe fault,are all favorable targets.Of these,the Qianmahe fault possesses a larger-scale heat-conducting and water-controlling structure.In addition,in the secondary fault-controlled area extending to the west,the zone between F2’and F4 exhibits renewed tectonic activity,suggesting a greater potential for geothermal resources. 展开更多
关键词 Heishan geothermal area wide-field electromagnetic method Medium-deep geothermal Heat-conducting structure DESERT
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Optical design of wide-field and broadband light field camera for high-precision optical surface defect detection
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作者 Chengchen Zhou Yukun Wang +7 位作者 Yue Ding Dacheng Wang Jiucheng Nie Jialong Li Zhixi Li Zheng Zhou Shuangshuang Zhang Xiaokun Wang 《Astronomical Techniques and Instruments》 2026年第1期64-74,共11页
To address the challenges of high-precision optical surface defect detection,we propose a novel design for a wide-field and broadband light field camera in this work.The proposed system can achieve a 50°field of ... To address the challenges of high-precision optical surface defect detection,we propose a novel design for a wide-field and broadband light field camera in this work.The proposed system can achieve a 50°field of view and operates at both visible and near-infrared wavelengths.Using the principles of light field imaging,the proposed design enables 3D reconstruction of optical surfaces,thus enabling vertical surface height measurements with enhanced accuracy.Using Zemax-based simulations,we evaluate the system’s modulation transfer function,its optical aberrations,and its tolerance to shape variations through Zernike coefficient adjustments.The results demonstrate that this camera can achieve the required spatial resolution while also maintaining high imaging quality and thus offers a promising solution for advanced optical surface defect inspection. 展开更多
关键词 Optical design Defect detection wide-field camera Broadband light field camera
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Metalens-integrated compact imaging devices for wide-field microscopy 被引量:20
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作者 Beibei Xu Hanmeng Li +6 位作者 Shenglun Gao Xia Hu Cheng Yang Chen Chen Feng Yan Shining Zhu Tao Li 《Advanced Photonics》 EI CSCD 2020年第6期1-8,共8页
Metasurfaces have demonstrated unprecedented capabilities in manipulating light with ultrathin and flat architectures.Although great progress has been made in the metasurface designs and function demonstrations,most m... Metasurfaces have demonstrated unprecedented capabilities in manipulating light with ultrathin and flat architectures.Although great progress has been made in the metasurface designs and function demonstrations,most metalenses still only work as a substitution of conventional lenses in optical settings,whose integration advantage is rarely manifested.We propose a highly integrated imaging device with silicon metalenses directly mounted on a complementary metal oxide semiconductor image sensor,whose working distance is in hundreds of micrometers.The imaging performances including resolution,signal-to-noise ratio,and field of view(FOV)are investigated.Moreover,we develop a metalens array with polarization-multiplexed dual-phase design for a wide-field microscopic imaging.This approach remarkably expands the FOV without reducing the resolution,which promises a non-limited space-bandwidth product imaging for wide-field microscopy.As a result,we demonstrate a centimeter-scale prototype for microscopic imaging,showing uniqueness of meta-design for compact integration. 展开更多
关键词 metalens compact imaging device polarization multiplexing wide-field microscopy.
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Chip-scale metalens microscope for wide-field and depth-of-field imaging 被引量:8
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作者 Xin Ye Xiao Qian +7 位作者 Yuxin Chen Rui Yuan Xingjian Xiao Chen Chen Wei Hu Chunyu Huang Shining Zhu Tao Li 《Advanced Photonics》 SCIE EI CAS CSCD 2022年第4期68-75,共8页
Microscopy is very important in research and industry,yet traditional optical microscopy suffers from the limited field-of-view(FOV)and depth-of-field(DOF)in high-resolution imaging.We demonstrate a simultaneous large... Microscopy is very important in research and industry,yet traditional optical microscopy suffers from the limited field-of-view(FOV)and depth-of-field(DOF)in high-resolution imaging.We demonstrate a simultaneous large FOV and DOF microscope imaging technology based on a chip-scale metalens device that is implemented by a SiNxmetalens array with a co-and cross-polarization multiplexed dual-phase design and dispersive spectrum zoom effect.A 4-mm×4-mm FOV is obtained with a resolution of 1.74μm and DOF of200μm within a wavelength range of 450 to 510 nm,which definitely exceeds the performance of traditional microscopes with the same resolution.Moreover,it is realized in a miniaturized compact prototype,showing an overall advantage for portable and convenient microscope technology. 展开更多
关键词 metalens MICROSCOPE wide-field imaging
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Wide-field ophthalmic space-division multiplexing optical coherence tomography 被引量:4
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作者 JASON JERWICK YONGYANG HUANG +3 位作者 ZHAO DONG ADRIENNE SLAUDADES ALEXANDER J.BRUCKER CHAO ZHOU 《Photonics Research》 SCIE EI CSCD 2020年第4期539-547,共9页
High-speed ophthalmic optical coherence tomography(OCT)systems are of interest because they allow rapid,motion-free,and wide-field retinal imaging.Space-division multiplexing optical coherence tomography(SDMOCT)is a h... High-speed ophthalmic optical coherence tomography(OCT)systems are of interest because they allow rapid,motion-free,and wide-field retinal imaging.Space-division multiplexing optical coherence tomography(SDMOCT)is a high-speed imaging technology that takes advantage of the long coherence length of micro electro mechanical vertical cavity surface emitting laser sources to multiplex multiple images along a single imaging depth.We demonstrate wide-field retinal OCT imaging,acquired at an effective A-scan rate of 800,000 A-scans/s with volumetric images covering up to 12.5 mm×7.4 mm on the retina and captured in less than 1 s.A clinical feasibility study was conducted to compare the ophthalmic SDM-OCT with commercial OCT systems,illustrating the high-speed capability of SDM-OCT in a clinical setting. 展开更多
关键词 wide-field ophthalmic space-division multiplexing optical coherence tomography
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Design of a wide-field target detection and tracking system using the segmented planar imaging detector for electro-optical reconnaissance 被引量:9
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作者 于清华 武冬梅 +1 位作者 陈福春 孙胜利 《Chinese Optics Letters》 SCIE EI CAS CSCD 2018年第7期34-39,共6页
Detecting and tracking multiple targets simultaneously for space-based surveillance requires multiple cameras,which leads to a large system volume and weight. To address this problem, we propose a wide-field detection... Detecting and tracking multiple targets simultaneously for space-based surveillance requires multiple cameras,which leads to a large system volume and weight. To address this problem, we propose a wide-field detection and tracking system using the segmented planar imaging detector for electro-optical reconnaissance. This study realizes two operating modes by changing the working paired lenslets and corresponding waveguide arrays: a detection mode and a tracking mode. A model system was simulated and evaluated using the peak signal-to-noise ratio method. The simulation results indicate that the detection and tracking system can realize wide-field detection and narrow-field, multi-target, high-resolution tracking without moving parts. 展开更多
关键词 FOV Design of a wide-field target detection and tracking system using the segmented planar imaging detector for electro-optical reconnaissance
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超宽板坯连铸结晶器内传热和凝固过程的模拟研究
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作者 司新宇 姜显松 +2 位作者 涂凌峰 王强强 何生平 《炼钢》 北大核心 2026年第1期28-37,共10页
为了探究超宽板坯结晶器(断面2 920 mm×150 mm)内温度场和凝固坯壳的生长规律,建立了流动-传热-凝固的多场耦合数学模型,对比分析了有无坯壳对结晶器内部流场的影响,以及浸入式水口出口角度对凝固坯壳生长的影响。结果表明:凝固壳... 为了探究超宽板坯结晶器(断面2 920 mm×150 mm)内温度场和凝固坯壳的生长规律,建立了流动-传热-凝固的多场耦合数学模型,对比分析了有无坯壳对结晶器内部流场的影响,以及浸入式水口出口角度对凝固坯壳生长的影响。结果表明:凝固壳的存在会使超宽板坯结晶器内部流场产生明显变化,上下回流现象减弱,没有明显回流中心,特别是下回流区域比没有坯壳更小,因此忽略凝固坯壳会得到不准确的流场预测结果。由于超宽板坯具有较大的宽厚比,射流自浸入式水口射出后会以较大的动能首先与宽面发生撞击,撞击点附近出现局部高温区域,延缓该位置坯壳生长,使得凝固壳厚度有所下降。同时过早的碰撞耗散了较大动能,后续对两侧窄面的冲击弱,因此,较宽面而言,射流对窄面坯壳生长影响较小。与常规板坯坯壳生长不同的是,超宽板坯坯壳在持续拉出的过程中没有出现重熔现象。随着水口倾角的减小,10°较15°而言,宽面坯壳周向的温度差异减小,射流在窄面的撞击点上移,整个窄面高温区域随之上移,5°水口靠近弯月面区域温度更高,出现明显的坯壳生长减缓现象,致使最后在拉出结晶器时的坯壳厚度相较于10°和15°水口薄约1.5 mm。研究结果对超宽板坯结晶器流场和温度场的控制具有一定的指导意义,适当减少水口倾角(从15°减小到10°)对减少超宽板坯宽面纵裂纹发生率有一定的改善作用。 展开更多
关键词 水口倾角 超宽板坯 数值模拟 流场 凝固坯壳
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Chip-compatible wide-field 3D nanoscopy through tunable spatial frequency shift effect
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作者 Xiaowei Liu Mingwei Tang +6 位作者 Chao Meng Chenlei Pang Cuifang Kuang Wei Chen Clemens F.Kaminski Qing Yang Xu Liu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2021年第9期41-50,共10页
Spatial frequency shift(SFS) microscopy with evanescent wave illumination shows intriguing advantages, including large field of view(FOV), high speed, and good modularity. However, a missing band in the spatial freque... Spatial frequency shift(SFS) microscopy with evanescent wave illumination shows intriguing advantages, including large field of view(FOV), high speed, and good modularity. However, a missing band in the spatial frequency domain hampers the SFS superresolution microscopy from achieving resolution better than 3 folds of the Abbe diffraction limit. Here, we propose a novel tunable large-SFS microscopy, making the resolution improvement of a linear system no longer restricted by the detection numerical aperture(NA). The complete wide-range detection in the spatial frequency domain is realized by tuning the illumination spatial frequency actively and broadly through an angle modulation between the azimuthal propagating directions of two evanescent waves. The vertical spatial frequency is tuned via a sectional saturation effect, and the reconstructed depth information can be added to the lateral superresolution mask for 3D imaging. A lateral resolution of λ/9, and a vertical localization precision of ~λ/200(detection objective NA = 0.9) are realized with a gallium phosphide(GaP) waveguide. Its unlimited resolution enhancing capability is demonstrated by introducing a designed metamaterial chip with an unusual large refractive index. Besides the great resolution enhancement, this method shows better anti-noise capability than classical structured illumination microscopy without SFS tunability. This method is chip-compatible and can potentially provide a massproducible illumination chip module achieving the fast, large-FOV, and deep-subwavelength 3D nanoscopy. 展开更多
关键词 superresolution spatial frequency shift evanescent wave wide-field microscopy chip-compatible microscopy
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Simple and High-Efficiency Preparation Method of Biometric 3D Artificial Compound Eyes for Wide-Field Imaging
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作者 Wu Xinxue Fang Chaolong +1 位作者 Li Zhihong Zhang Yaoju 《激光与光电子学进展》 CSCD 北大核心 2021年第12期523-531,共9页
Three-dimensional(3D)artificial compound eyes(ACEs)are helpful for wide field-o-fview imaging and sensing system applications.However,existing batch preparation methods are technically challenging.A bio-inspired,simpl... Three-dimensional(3D)artificial compound eyes(ACEs)are helpful for wide field-o-fview imaging and sensing system applications.However,existing batch preparation methods are technically challenging.A bio-inspired,simple,and high-efficiency batch preparation method is proposed,which involves bonding a sticky microlens array(MLA)polydimethylsiloxane(PDMS)film to an elastic PDMS hemisphere under pressure,followed by abrupt pressure removal.Characterizations from a scanning electron microscope and laser scanning confocal microscope show that 3D ACEs prepared using the proposed method have high numbers of uniformly distributed ommatidia with a high-quality finish.Furthermore,optical imaging investigations demonstrate that the proposed preparation method can achieve clear,distortionfree imaging with a wide field-of-view(up to 140.2°). 展开更多
关键词 imaging systems artificial compound eye microlens array FLEXIBILITY wide-field imaging
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Characterization of the current crowding effect on chip surface using a quantum wide-field microscope
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作者 Rui Zhao Ding Wang +3 位作者 Huan Fei Wen Yunbo Shi Jun Tang Jun Liu 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第6期123-128,共6页
We characterize the current crowding effect for microwave radiation on a chip surface based on a quantum wide-field microscope combining a wide-field reconstruction technique. A swept microwave signal with the power o... We characterize the current crowding effect for microwave radiation on a chip surface based on a quantum wide-field microscope combining a wide-field reconstruction technique. A swept microwave signal with the power of 0–30 d Bm is supplied to a dumbbell-shaped microstrip antenna, and the significant differences in microwave magnetic-field amplitudes attributed to the current crowding effect are experimentally observed in a 2.20 mm ×1.22 mm imaging area. The normalized microwave magnetic-field amplitude along the horizontal geometrical center of the image area further demonstrates the feasibility of the characterization of the current crowding effect. The experiments indicate the proposal can be qualified for the characterization of the anomalous area of the radio-frequency chip surface. 展开更多
关键词 current crowding effect microwave field on chip surface quantum wide-field microscope nitrogen-vacancy center
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High-Throughput,Low Background,and Wide-Field Microscopy by Flat-Field Photobleaching Imprinting Microscopy
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作者 Yizhi Qin Mengling Zhang +3 位作者 Huiwen Hao Boxin Xue Jiahao Niu Yujie Sun 《Chemical & Biomedical Imaging》 2023年第9期843-851,共9页
Wide-field photobleaching imprinting microscopy(PIM)can improve fluorescence image contrast by cleverly exploiting the fluorophores’photobleaching properties.However,as conventional wide-field PIM commonly adopts Gau... Wide-field photobleaching imprinting microscopy(PIM)can improve fluorescence image contrast by cleverly exploiting the fluorophores’photobleaching properties.However,as conventional wide-field PIM commonly adopts Gaussian illumination with a nonuniform lateral fluence distribution,the field-of-view(FOV)and sampling density are largely reduced.In addition,the slow axial fluence gradient of Gaussian illumination limits the signal-to-background ratio(SBR)improvement and optical sectioning capability of PIM.Here,we present flat-field photobleaching imprinting microscopy(ffPIM)with a uniform lateral excitation fluence and sharp axial intensity gradient at the focal plane.ffPIM demonstrates low background,large FOV,and thin optical section.More importantly,compared to either conventional wide-field PIM or light-sheet microscopy,ffPIM shows much better balance for FOV,sampling density,SBR,and optical sectioning capability.The performance of ffPIM is characterized by simulation and resolving multiple cellular structures.Finally,ffPIM can be easily implemented to a standard commercial wide-field microscope and,thereby,allow general laboratories to benefit from this technique. 展开更多
关键词 Photobleaching imprinting microscopy wide-field microscopy Flat-field illumination Background-free fluorescence imaging HIGH-THROUGHPUT Optical section
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相干FDA雷达收发联合多波束方法
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作者 张军 许京伟 +3 位作者 王柯祎 廖桂生 李军 蔡兴雨 《系统工程与电子技术》 北大核心 2025年第5期1487-1494,共8页
针对相干频率分集阵列雷达距离/时间-角度依赖的信号收、发处理问题,提出一种基于角度依赖匹配滤波的频率分集阵雷达收发联合多波束设计方法。该方法可以同时实现等效发射数字波束形成和信号脉冲压缩匹配处理。且不同空间角度的雷达回... 针对相干频率分集阵列雷达距离/时间-角度依赖的信号收、发处理问题,提出一种基于角度依赖匹配滤波的频率分集阵雷达收发联合多波束设计方法。该方法可以同时实现等效发射数字波束形成和信号脉冲压缩匹配处理。且不同空间角度的雷达回波信号可以独立进行处理,通过联合接收数字波束形成技术,可以同时进行收发联合波束形成,实现同时多波束广域宽角覆盖,满足雷达广域搜索任务的需要。仿真实验证明了所提方法的有效性。 展开更多
关键词 相干频率分集阵列 角度依赖匹配滤波 收发联合波束形成 广域宽角覆盖
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基于红外-可见光双波段的扫描型宽视场成像方法
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作者 代少升 郑昭 +1 位作者 陈昌川 蒋大川 《半导体光电》 北大核心 2025年第5期884-891,共8页
针对目前红外成像设备中可见光与红外波段成像分辨率低、视场小以及图像位置映射关系不一致等问题,提出一种基于红外-可见光双波段的扫描型宽视场成像方法。该方法首先使用阵列传感器采集物体的可见光波段图像,使用单元红外探测器感应... 针对目前红外成像设备中可见光与红外波段成像分辨率低、视场小以及图像位置映射关系不一致等问题,提出一种基于红外-可见光双波段的扫描型宽视场成像方法。该方法首先使用阵列传感器采集物体的可见光波段图像,使用单元红外探测器感应目标的红外热辐射,并通过电机驱动,以线扫描方式实现红外波段成像;然后根据可见光像素均匀分布与红外像素等角度分布的特点,在像素世界坐标系上实现正圆切割映射;最后利用扫描角度温度模型对红外图像进行温度补偿。结果表明,所提方法可以有效同步的采集可见光与红外波段图像,使可见光与红外图像在长、宽视场角度上具有1∶1的映射比,对红外与可见光双波段成像推广应用具有参考意义。 展开更多
关键词 双波段 红外可见光 宽视场 温度补偿 扫描
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基于趋肤深度加权的横向约束拟二维反演在广域电磁法中的应用
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作者 肖晓 李银航 +1 位作者 汤井田 刘寄仁 《地球物理学进展》 北大核心 2025年第5期2114-2122,共9页
广域电磁法是中深部矿产勘探的重要手段,本文针对广域电磁法数据特点,提出了一种基于趋肤深度加权的横向约束拟二维反演算法(SD-WLCI).通过两个二维理论模型证明了该算法能够有效改善广域电磁法中深部反演结果在横向上的连续性,提高层... 广域电磁法是中深部矿产勘探的重要手段,本文针对广域电磁法数据特点,提出了一种基于趋肤深度加权的横向约束拟二维反演算法(SD-WLCI).通过两个二维理论模型证明了该算法能够有效改善广域电磁法中深部反演结果在横向上的连续性,提高层分界面的分辨率.除此之外,本文还详细比较了三种正则化因子搜索方法(线性搜索法、冷却法、自适应正则化因子法)对于此算法的影响,结果表明,在所对比的范围内,线性搜索法在工作效率和稳定性两方面均优于其他两种方法.最后,本文将基于趋肤深度加权的横向约束反演算法应用于铜陵冬瓜山某矿区实测的广域电磁法数据反演,反演结果与实际地质情况吻合度高,为后续中深部矿产预测和钻孔选址提供了可靠的地球物理依据,并通过与传统的横向约束反演结果进行对比,证明了该算法在广域电磁法实测数据反演中的实用性与必要性. 展开更多
关键词 广域电磁法 横向约束 趋肤深度加权 正则化因子 实测数据反演
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