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Multimodality image registration and fusion using neural network
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作者 Mostafa G Mostafa Aly A Farag Edward Essock 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2003年第3期235-240,共6页
Multimodality image registration and fusion are essential steps in building 3-D models from remotesensing data. We present in this paper a neural network technique for the registration and fusion of multimodali-ty rem... Multimodality image registration and fusion are essential steps in building 3-D models from remotesensing data. We present in this paper a neural network technique for the registration and fusion of multimodali-ty remote sensing data for the reconstruction of 3-D models of terrain regions. A FeedForward neural network isused to fuse the intensity data sets with the spatial data set after learning its geometry. Results on real data arepresented. Human performance evaluation is assessed on several perceptual tests in order to evaluate the fusionresults. 展开更多
关键词 data fusion image registration image interpolation neural network 3-D model building
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Single-Shot 360-Degree Cranial Deformity Detection System Using Digital Image Correlation
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作者 Shaogang Liu Long Yin +2 位作者 Wei Yin Yuzhen Zhang Chao Zuo 《Journal of Beijing Institute of Technology》 EI CAS 2022年第2期131-139,共9页
In this paper,a single-shot 360-degree cranial deformity detection system using digital image correlation(DIC)is presented to quickly obtain and detect accurate 3D data of infants’cra-nium.By introducing plane mirror... In this paper,a single-shot 360-degree cranial deformity detection system using digital image correlation(DIC)is presented to quickly obtain and detect accurate 3D data of infants’cra-nium.By introducing plane mirrors into a stereo 3D DIC measurement system,a multi-view 3D imaging model is established to convert 3D data from real and virtual perspectives into 360-degree 3D data of the tested infant cranium,achieving single-shot and panoramic 3D measurement.Exper-imental results showed that the performance and measurement accuracy of the proposed system can meet the requirements for cranial deformity detection,which provides a fast,accurate,and low-cost solution medically. 展开更多
关键词 single-shot measurement 360-degree measurement cranial deformity detection
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A Preliminary Catalog of Early Aftershocks Following the 7 January 2025 M_(S)6.8 Dingri,Xizang Earthquake 被引量:4
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作者 Jiayuan Yao Dongdong Yao +3 位作者 Fang Chen Ming Zhi Li Sun Dun Wang 《Journal of Earth Science》 2025年第2期856-860,共5页
INTRODUCTION.On January 7,2025,at 9:05 AM BJT,a MS6.8 earthquake(CENC epicenter:28.50°N,87.45°E)struck Dingri County,Xizang Province(hereinafter referred to as the Dingri mainshock).The inferred moment magni... INTRODUCTION.On January 7,2025,at 9:05 AM BJT,a MS6.8 earthquake(CENC epicenter:28.50°N,87.45°E)struck Dingri County,Xizang Province(hereinafter referred to as the Dingri mainshock).The inferred moment magnitude,based on regional/teleseismic waveform inversion and back-projection,is approximately MW7.1.Focal mechanism solutions,aftershock distribution,and field surveys indicate that the Dingri mainshock was a normal-faulting event,with a nearly north-south strike and a westward-dipping fault plane. 展开更多
关键词 focal mechanism Xizang AFTERSHOCKS Dingri moment magnitude field surveys EARTHQUAKE mechanism solutionsaftershock
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Revised global vertically integrated remanent magnetization model of the oceanic lithosphere with comparison to LCS-1 model and MSS-1 magnetic measurements 被引量:2
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作者 ShiDa Sun Hui Li +3 位作者 JinSong Du Pan Zhang Chao Chen PengFei Liu 《Earth and Planetary Physics》 2025年第3期653-666,共14页
The lithospheric magnetic field is an important component of the geomagnetic field,and the oceanic lithosphere exhibits distinct characteristics.Because of its formation mechanisms,evolutionary history,and geomagnetic... The lithospheric magnetic field is an important component of the geomagnetic field,and the oceanic lithosphere exhibits distinct characteristics.Because of its formation mechanisms,evolutionary history,and geomagnetic field polarity reversals,the oceanic lithosphere has significant remanent magnetization,which causes magnetic anomaly stripes parallel to the mid-ocean ridges.However,it is difficult to construct a high-resolution lithospheric magnetic field model in oceanic regions with relatively sparse data or no data.Using forward calculated lithospheric magnetic field data based on an oceanic remanent magnetization(ORM) model with physical and geological foundations as a supplement is a feasible approach.We first collect the latest available oceanic crust age grid,plate motion model,geomagnetic polarity timescale,and oceanic lithosphere thermal structure.Combining the assumptions that the paleo geomagnetic field is a geocentric axial dipole field and that the normal oceanic crust moves only in the horizontal direction,we construct a vertically integrated ORM model of the normal oceanic crust with a known age,including the intensity,inclination,and declination.Both the ORM model and the global induced magnetization(GIM) model are then scaled from two aspects between their forward calculated results and the lithospheric magnetic field model LCS-1.One aspect is the difference in their spherical harmonic power spectra,and the other is the misfit between the grid data over the oceans.We last compare the forward calculated lithospheric magnetic anomaly from the scaled ORM and GIM models with the Macao Science Satellite-1(MSS-1) observed data.The comparison results show that the magnetic anomalies over the normal oceanic crust regions at satellite altitude are mainly contributed by the high-intensity remanent magnetization corresponding to the Cretaceous magnetic quiet period.In these regions,the predicted and observed anomalies show good consistency in spatial distribution,whereas their amplitude differences vary across regions.This result suggests that regional ORM construction should be attempted in future work to address these amplitude discrepancies. 展开更多
关键词 oceanic remanent magnetization lithospheric magnetic field LCS-1 Macao Science Satellite-1
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Sensitivity analysis of the lithospheric magnetic field at satellite altitude:the effects of the inducing field and the shape of the magnetic lithosphere 被引量:1
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作者 JinSong Du YuKun Li +5 位作者 HouPu Li ChangQing Yuan KangAn Zhao JiangSong Gui Pan Zhang ShaoFeng Bian 《Earth and Planetary Physics》 2025年第3期642-652,共11页
As a means of quantitative interpretation,forward calculations of the global lithospheric magnetic field in the Spherical Harmonic(SH)domain have been widely used to reveal geophysical,lithological,and geothermal vari... As a means of quantitative interpretation,forward calculations of the global lithospheric magnetic field in the Spherical Harmonic(SH)domain have been widely used to reveal geophysical,lithological,and geothermal variations in the lithosphere.Traditional approaches either do not consider the non-axial dipolar terms of the inducing field and its radial variation or do so by means of complicated formulae.Moreover,existing methods treat the magnetic lithosphere either as an infinitesimally thin layer or as a radially uniform spherical shell of constant thickness.Here,we present alternative forward formulae that account for an arbitrarily high maximum degree of the inducing field and for a magnetic lithosphere of variable thickness.Our simulations based on these formulae suggest that the satellite magnetic anomaly field is sensitive to the non-axial dipolar terms of the inducing field but not to its radial variation.Therefore,in forward and inverse calculations of satellite magnetic anomaly data,the non-axial dipolar terms of the inducing field should not be ignored.Furthermore,our results show that the satellite magnetic anomaly field is sensitive to variability in the lateral thickness of the magnetized shell.In particular,we show that for a given vertically integrated susceptibility distribution,underestimating the thickness of the magnetic layer overestimates the induced magnetic field.This discovery bridges the greatest part of the alleged gap between the susceptibility values measured from rock samples and the susceptibility values required to match the observed magnetic field signal.We expect the formulae and conclusions of this study to be a valuable tool for the quantitative interpretation of the Earth's global lithospheric magnetic field,through an inverse or forward modelling approach. 展开更多
关键词 lithospheric magnetic field forward calculation spherical harmonic analysis sensitivity analysis satellite magnetism
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An alternative regularization approach for modeling the regional lithospheric magnetic field from satellite magnetic measurements by the spherical equivalent source method and its application in Africa 被引量:1
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作者 JiangSong Gui JinSong Du +5 位作者 Pan Zhang ChangQing Yuan YuKun Li KangAn Zhao Liang Yin HouPu Li 《Earth and Planetary Physics》 2025年第3期697-710,共14页
The equivalent source(ES)method in the spherical coordinate system has been widely applied to processing,reduction,field modeling,and geophysical and geological interpretation of satellite magnetic anomaly data.Howeve... The equivalent source(ES)method in the spherical coordinate system has been widely applied to processing,reduction,field modeling,and geophysical and geological interpretation of satellite magnetic anomaly data.However,the inversion for the ES model suffers from nonuniqueness and instability,which remain unresolved.To mitigate these issues,we introduce both the minimum and flattest models into the model objective function as an alternative regularization approach in the spherical ES method.We first present the methods,then analyze the accuracy of forward calculation and test the proposed ES method in this study by using synthetic data.The experimental results from simulation data indicate that our proposed regularization effectively suppresses the Backus effect and mitigates inversion instability in the low-latitude region.Finally,we apply the proposed method to magnetic anomaly data from China Seismo-Electromagnetic Satellite-1(CSES-1)and Macao Science Satellite-1(MSS-1)magnetic measurements over Africa by constructing an ES model of the large-scale lithospheric magnetic field.Compared with existing global lithospheric magnetic field models,our ES model demonstrates good consistency at high altitudes and predicts more stable fields at low altitudes.Furthermore,we derive the reduction to the pole(RTP)magnetic anomaly fields and the apparent susceptibility contrast distribution based on the ES model.The latter correlates well with the regional tectonic framework in Africa and surroundings. 展开更多
关键词 regional lithospheric magnetic field model spherical equivalent source method satellite magnetism AFRICA MSS-1 CSES-1
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A 100-degree lithospheric magnetic field model constructed using MSS-1,Swarm-A,and CHAMP satellite data 被引量:1
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作者 JiaXuan Zhang Yan Feng +3 位作者 Pan Zhang YuXuan Lin XinWu Li Ya Huang 《Earth and Planetary Physics》 2025年第3期667-676,共10页
By combining data from the Challenging Minisatellite Payload(CHAMP),Swarm-A,and newest Macao Science Satellite-1(MSS-1) missions,we constructed a lithospheric magnetic field model up to spherical harmonic degree N = 1... By combining data from the Challenging Minisatellite Payload(CHAMP),Swarm-A,and newest Macao Science Satellite-1(MSS-1) missions,we constructed a lithospheric magnetic field model up to spherical harmonic degree N = 100.To isolate the lithospheric magnetic field signals,we utilized the latest CHAOS-8(CHAMP,Φrsted,and SAC-C 8) model and MGFM(Multisource Geomagnetic Field Model) to remove nonlithospheric sources,including the core field,magnetospheric field,ocean tidal field,and ocean circulation field.Subsequently,orbit-by-orbit processing was applied to both scalar and vector data,such as spherical harmonic high-pass filtering,singular spectrum analysis,and line leveling,to suppress noise and residual signals along the satellite tracks.With an orbital inclination of only 41°,MSS-1 effectively captures fine-scale lithospheric magnetic field signals in mid-to low-latitude regions.Its data exhibit a root mean square error of only 0.77 nT relative to the final model,confirming the high quality and utility of lithospheric field modeling.The resulting model exhibits excellent consistency with the MF7(Magnetic Field Model 7),maintaining a high correlation up to N = 90 and still exceeding 0.65 at N = 100.These results demonstrate the reliability and value of MSS-1 data in global lithospheric magnetic field modeling. 展开更多
关键词 lithospheric magnetic field Macao Science Satellite-1(MSS-1) line leveling Magnetic Field Model 7(MF7) singular spectrum analysis
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A high-resolution lithospheric magnetic field model of China and surroundings by using CHAMP,Swarm,CSES-1,and MSS-1 satellite magnetic measurements and aeromagnetic anomaly data 被引量:1
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作者 Pan Zhang JinSong Du +5 位作者 Liang Yin Qing Yan JiaXuan Zhang HouPu Li Keke Zhang Chao Chen 《Earth and Planetary Physics》 2025年第3期686-696,共11页
The CUG_CLMFM3D series comprises high-resolution three-dimensional lithospheric magnetic field models for China and its surroundings.The first version,CUG_CLMFM3Dv1,is a spherical cap harmonic model integrating the WD... The CUG_CLMFM3D series comprises high-resolution three-dimensional lithospheric magnetic field models for China and its surroundings.The first version,CUG_CLMFM3Dv1,is a spherical cap harmonic model integrating the WDMAMv2(World Digital Magnetic Anomaly Map version 2)global magnetic anomaly grid and nearly a decade of CHAMP(Challenging Minisatellite Payload for Geophysical Research and Application)satellite vector data.It achieves a~5.7 km resolution but has limitations:the WDMAMv2 grid lacks high-resolution data in the southern Xinjiang and Tibet regions,which leads to missing small-to medium-scale anomalies,and unfiltered CHAMP data introduce low-frequency conflicts with global spherical harmonic models.Above the altitude of 150 km,correlations with global models drop below 0.9.The second version,CUG_CLMFM3Dv2,addresses these issues by incorporating 5-km-resolution aeromagnetic data and rigorously processed satellite data from CHAMP,Swarm,CSES-1(China Seismo-Electromagnetic Satellite 1),and MSS-1(Macao Science Satellite 1).The comparison analysis shows that the CUG_CLMFM3Dv2 captures finer high-frequency details and more stable long-wavelength signals,offering improved magnetic anomaly maps for further geological and geophysical studies. 展开更多
关键词 Macao Science Satellite 1 China Seismo-Electromagnetic Satellite 1 revised spherical cap harmonic analysis high resolution lithospheric magnetic field China and surroundings
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Enhanced photoacoustic microscopy with physics-embedded degeneration learning
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作者 Haigang Ma Shili Ren +4 位作者 Xiang Wei Yinshi Yu Jiaming Qian Qian Chen Chao Zuo 《Opto-Electronic Advances》 2025年第3期17-35,共19页
Deep learning(DL)is making significant inroads into biomedical imaging as it provides novel and powerful ways of accurately and efficiently improving the image quality of photoacoustic microscopy(PAM).Off-the-shelf DL... Deep learning(DL)is making significant inroads into biomedical imaging as it provides novel and powerful ways of accurately and efficiently improving the image quality of photoacoustic microscopy(PAM).Off-the-shelf DL models,however,do not necessarily obey the fundamental governing laws of PAM physical systems,nor do they generalize well to scenarios on which they have not been trained.In this work,a physics-embedded degeneration learning(PEDL)approach is proposed to enhance the image quality of PAM with a self-attention enhanced U-Net network,which obtains greater physical consistency,improves data efficiency,and higher adaptability.The proposed method is demonstrated on both synthetic and real datasets,including animal experiments in vivo(blood vessels of mouse's ear and brain).And the results show that compared with previous DL methods,the PEDL algorithm exhibits good performance in recovering PAM images qualitatively and quantitatively.It overcomes the challenges related to training data,accuracy,and robustness which a typical data-driven approach encounters,whose exemplary application envisions to provide a new perspective for existing DL tools of enhanced PAM. 展开更多
关键词 photoacoustic microscopy deep learning high quality imaging physical model
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Aberration-corrected differential phase contrast microscopy with annular illuminations
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作者 Yao Fan Chenyue Zheng +6 位作者 Yefeng Shu Qingyang Fu Lixiang Xiong Guifeng Lu Jiasong Sun Chao Zuo Qian Chen 《Opto-Electronic Science》 2025年第8期2-12,共11页
Quantitative phase imaging(QPI)enables non-invasive cellular analysis by utilizing cell thickness and refractive index as intrinsic probes,revolutionizing label-free microscopy in cellular research.Differential phase ... Quantitative phase imaging(QPI)enables non-invasive cellular analysis by utilizing cell thickness and refractive index as intrinsic probes,revolutionizing label-free microscopy in cellular research.Differential phase contrast(DPC),a non-interferometric QPI technique,requires only four intensity images under asymmetric illumination to recover the phase of a sample,offering the advantages of being label-free,non-coherent and highly robust.Its phase reconstruction result relies on precise modeling of the phase transfer function(PTF).However,in real optical systems,the PTF will deviate from its theoretical ideal due to the unknown wavefront aberrations,which will lead to significant artifacts and distortions in the reconstructed phase.We propose an aberration-corrected DPC(ACDPC)method that utilizes three intensity images under annular illumination to jointly retrieve the aberration and the phase,achieving high-quality QPI with minimal raw data.By employing three annular illuminations precisely matched to the numerical aperture of the objective lens,the object information is transmitted into the acquired intensity with a high signal-to-noise ratio.Phase retrieval is achieved by an iterative deconvolution algorithm that uses simulated annealing to estimate the aberration and further employs regularized deconvolution to reconstruct the phase,ultimately obtaining a refined complex pupil function and an aberration-corrected quantitative phase.We demonstrate that ACDPC is robust to multi-order aberrations without any priori knowledge,and can effectively retrieve and correct system aberrations to obtain high-quality quantitative phase.Experimental results show that ACDPC can clearly reproduce subcellular structures such as vesicles and lipid droplets with higher resolution than conventional DPC,which opens up new possibilities for more accurate subcellular structure analysis in cell biology. 展开更多
关键词 quantitative phase imaging differential phase contrast aberration-corrected annular illumination
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Forecasting Solar Energy Production across Multiple Sites Using Deep Learning
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作者 Samira Marhraoui Basma Saad +2 位作者 Hassan Silkan Said Laasri Asmaa El Hannani 《Energy Engineering》 2025年第7期2653-2672,共20页
Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficie... Photovoltaic(PV)power forecasting is essential for balancing energy supply and demand in renewable energy systems.However,the performance of PV panels varies across different technologies due to differences in efficiency and how they process solar radiation.This study evaluates the effectiveness of deep learning models in predicting PV power generation for three panel technologies:Hybrid-Si,Mono-Si,and Poly-Si,across three forecasting horizons:1-step,12-step,and 24-step.Among the tested models,the Convolutional Neural Network—Long Short-Term Memory(CNN-LSTM)architecture exhibited superior performance,particularly for the 24-step horizon,achieving R^(2)=0.9793 and MAE 0.0162 for the Poly-Si array,followed by Mono-Si(R^(2)=0.9768)and Hybrid-Si arrays(R^(2)=0.9769).These findings demonstrate that the CNN-LSTM model can provide accurate and reliable PV power predictions for all studied technologies.By identifying the most suitable predictive model for each panel technology,this study contributes to optimizing PV power forecasting and improving energy management strategies. 展开更多
关键词 CNN-LSTM deep learning models forecasting horizons PV energy prediction accuracy solar panel technologies
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Refining Single-Atom Catalytic Kinetics for Tumor Homologous-Targeted Catalytic Therapy
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作者 Hengke Liu Shan Lei +4 位作者 Hongyu Li Jiayingzi Wu Ting He Jing Lin Peng Huang 《Nano-Micro Letters》 2025年第10期565-578,共14页
Single-atom nanozymes(SAzymes)hold significant potential for tumor catalytic therapy,but their effectiveness is often compromised by low catalytic efficiency within tumor microenvironment.This efficiency is mainly inf... Single-atom nanozymes(SAzymes)hold significant potential for tumor catalytic therapy,but their effectiveness is often compromised by low catalytic efficiency within tumor microenvironment.This efficiency is mainly influenced by key factors including hydrogen peroxide(H_(2)O_(2))availability,acidity,and temperature.Simultaneous optimization of these key factors presents a significant challenge for tumor catalytic therapy.In this study,we developed a comprehensive strategy to refine single-atom catalytic kinetics for enhancing tumor catalytic therapy through dual-enzyme-driven cascade reactions.Iridium(Ir)SAzymes with high catalytic activity and natural enzyme glucose oxidase(GOx)were utilized to construct the cascade reaction system.GOx was loaded by Ir SAzymes due to its large surface area.Then,the dual-enzyme-driven cascade reaction system was modified by cancer cell membranes for improving biocompatibility and achieving tumor homologous targeting ability.GOx catalysis reaction could produce abundant H2O2 and lower the local p H,thereby optimizing key reaction-limiting factors.Additionally,upon laser irradiation,Ir SAzymes could raise local temperature,further enhancing the catalytic efficiency of dual-enzyme system.This comprehensive optimization maximized the performance of Ir SAzymes,significantly improving the efficiency of catalytic therapy.Our findings present a strategy of refining single-atom catalytic kinetics for tumor homologous-targeted catalytic therapy. 展开更多
关键词 Single-atom nanozymes Glucose oxidase Biomimetic cascade catalysis Tumor catalytic therapy Mild-temperature photothermal therapy
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Dual-frequency angular-multiplexed fringe projection profilometry with deep learning:breaking hardware limits for ultra-high-speed 3D imaging
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作者 Wenwu Chen Yifan Liu +8 位作者 Shijie Feng Wei Yin Jiaming Qian Yixuan Li Hang Zhang Maciej Trusiak Malgorzata Kujawinska Qian Chen Chao Zuo 《Opto-Electronic Advances》 2025年第9期15-24,共10页
Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pa... Recent advancements in artificial intelligence have transformed three-dimensional(3D)optical imaging and metrology,enabling high-resolution and high-precision 3D surface geometry measurements from one single fringe pattern projection.However,the imaging speed of conventional fringe projection profilometry(FPP)remains limited by the native sensor refresh rates due to the inherent"one-to-one"synchronization mechanism between pattern projection and image acquisition in standard structured light techniques.Here,we present dual-frequency angular-multiplexed fringe projection profilometry(DFAMFPP),a deep learning-enabled 3D imaging technique that achieves high-speed,high-precision,and large-depth-range absolute 3D surface measurements at speeds 16 times faster than the sensor's native frame rate.By encoding multi-timeframe 3D information into a single multiplexed image using multiple pairs of dual-frequency fringes,high-accuracy absolute phase maps are reconstructed using specially trained two-stage number-theoretical-based deep neural networks.We validate the effectiveness of DFAMFPP through dynamic scene measurements,achieving 10,000 Hz 3D imaging of a running turbofan engine prototype with only a 625 Hz camera.By overcoming the sensor hardware bottleneck,DFAMFPP significantly advances high-speed and ultra-high-speed 3D imaging,opening new avenues for exploring dynamic processes across diverse scientific disciplines. 展开更多
关键词 3D imaging fringe projection profilometry deep learning multiplex ultra-high-speed
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Photoinduced Three-Component Carboimination of Alkenes to Accessγ-Aminobutyric Acid Derivatives
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作者 Lu Tan Weicai Li +6 位作者 Shijing Tu Xinyu Zhong Xinhao Li Xi Du Zhijie Zhang Siping Wei Dong Yi 《Chinese Journal of Chemistry》 2025年第19期2533-2538,共6页
The remarkable biological activities ofγ-aminobutyric acid derivatives(GABAs)spurred the exploration of green and efficient synthetic methods to construct these scaffolds.Herein,we have developed a catalyst-free phot... The remarkable biological activities ofγ-aminobutyric acid derivatives(GABAs)spurred the exploration of green and efficient synthetic methods to construct these scaffolds.Herein,we have developed a catalyst-free photoinduced strategy for the redox-neutral three-component carboimination of alkenes,enabling efficient and modular assembly of a wide range ofγ-aminobutyric acid derivatives.Mechanistic studies indicate that this reaction is initiated with an electron donor-acceptor complex between deprotonated malonates and O-aryl oximes.Furthermore,the resulting products could be further converted to functionalizedγ-lactam derivatives through an acidic lactamization process. 展开更多
关键词 Electron donor-acceptor v-Aminobutyric acid THREE-COMPONENT Radical reactions Malonates Carboimination Photocatalyst-free
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A cubed-sphere based method for global and regional modeling of the lithospheric magnetic field
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作者 Liang Yin JiaXuan Zhang +3 位作者 PengFei Liu HongBo Yao Pan Zhang JinSong Du 《Earth and Planetary Physics》 2025年第3期622-634,共13页
The Earth's magnetic field,which has been extensively observed from ground to satellite altitudes over several decades,originates from multiple sources,such as the core dynamo,the conductive mantle,the magnetized ... The Earth's magnetic field,which has been extensively observed from ground to satellite altitudes over several decades,originates from multiple sources,such as the core dynamo,the conductive mantle,the magnetized lithosphere,and the space current systems.Modeling of the lithospheric contribution plays an important role in the geophysical studies and industrial applications.In this paper,we propose a new method for global and regional modeling of the lithospheric magnetic field based on the cubed-sphere.An equivalent dipole source method on a quasi-uniform cubed-sphere grid is employed in the forward modeling.The dipole directions are fixed according to a priori magnetization and the relative intensities are estimated by an inversion procedure of least-squares fitting with minimum model regularization.Several numerical tests are performed to validate the accuracy and efficiency of both forward modeling and inversion procedure.The proposed method is applied to the global and regional modeling based on the latest magnetic data from Swarm Alpha satellite and MSS-1 mission.The model results indicate that the proposed method works quite well for realistic satellite data and MSS-1 data is consistent with the Swarm data in terms of lithospheric field modeling. 展开更多
关键词 geomagnetic satellite lithospheric magnetic field cubed-sphere grid forward modeling INVERSION
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Spectral characteristics of the digital filter for electromagnetic field decomposition in 3D MCSEM
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作者 Wang Shu-Ming Di Qing-Yun +2 位作者 Xiao Yun-xin Fang Qi-chao Li De-shan 《Applied Geophysics》 2025年第3期563-570,891,共9页
The data of marine-controlled source electromagnetic exploration collected in shallow waters are considerably influenced by airwaves.Thus,finding ways to eliminate this influence is important.Decomposing the electroma... The data of marine-controlled source electromagnetic exploration collected in shallow waters are considerably influenced by airwaves.Thus,finding ways to eliminate this influence is important.Decomposing the electromagnetic field into the upgoing and downgoing fields is an effective method to resolve this problem.By utilizing the Stratton-Chu integral transform,this study proposes a novel method that can separate a 3D electromagnetic field into upgoing and downgoing electromagnetic fields through rigorous mathematical deduction.We examine the spectral characteristics to determine the effectiveness of the method.The results show that a practical digital filter can be achieved by selecting a reasonable window size and spatial step,as demonstrated through spectral comparisons with an analytical filter. 展开更多
关键词 MCSEM airwave electromagnetic field separation digital filter
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局部指数标架小波束在复杂介质方向照明分析中的应用 被引量:11
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作者 毛剑 吴如山 +1 位作者 高静怀 耿瑜 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2010年第12期2955-2963,共9页
提出了用局部指数标架小波束进行角度域分解的方法,解决了局部余弦基和局部正弦基缺乏单一方向性的问题.局部指数标架由局部余弦基和局部正弦基线性组合而成,是冗余度为2的紧标架.利用局部余弦变换和局部正弦变换的快速算法,能使基于局... 提出了用局部指数标架小波束进行角度域分解的方法,解决了局部余弦基和局部正弦基缺乏单一方向性的问题.局部指数标架由局部余弦基和局部正弦基线性组合而成,是冗余度为2的紧标架.利用局部余弦变换和局部正弦变换的快速算法,能使基于局部指数标架进行方向照明分析的计算效率较常用的局部倾斜叠加和Gabor-Daubechies标架等方法具有更为明显的优势.通过计算二维SEG/EAGE模型和SIGSBEE模型的方向照明图以及采集系统倾角响应图证实了本文方法的有效性.该方法的高效性使其在三维模型的方向照明分析和大规模的工业应用中具有广阔前景. 展开更多
关键词 局部余弦基 局部指数标架 局部角度域 偏移成像 方向照明分析 采集孔径
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局部角度域波传播步进算法研究 被引量:6
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作者 高静怀 周艳辉 +3 位作者 毛剑 陈文超 吴如山 李幼铭 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2007年第1期248-259,共12页
本文从非均匀介质中波动方程出发,提出了基于一般标架的相空间(局部角度域)波传播的步进算法.该方法在构造单程波的步进算法时,在选择标架或正交基等方面有更大的自由度.我们以不随频率及深度变化且具有变尺度特性的Gabor-Daubechies紧... 本文从非均匀介质中波动方程出发,提出了基于一般标架的相空间(局部角度域)波传播的步进算法.该方法在构造单程波的步进算法时,在选择标架或正交基等方面有更大的自由度.我们以不随频率及深度变化且具有变尺度特性的Gabor-Daubechies紧标架为例,给出了单程波传输算子的具体形式及相应的波场步进算法;详细讨论了基于Gabor-Daubechies标架的传输算子的高频渐近展开问题,得出了在高频、小传输步长条件下传输算子的近似解析表达式,并给出使用条件.通过模型算例,比较了精确传输算子与高频近似传输算子用于非均匀介质中波传播的结果,说明在一定条件下由两者得出的波场几乎是相同的. 展开更多
关键词 单程波传播 Gabor-Daubechies标架 非均匀介质 局部角度域 步进算法
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波动方程偏移成像阴影的照明补偿 被引量:30
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作者 陈生昌 马在田 Ru Ru-Shan 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2007年第3期844-850,共7页
受地下复杂构造和地震数据采集系统的影响,使地震波对地下目标的照明出现不均匀性,地震采集系统难以有效地获取地下某些目标的反射信息,进而使数据偏移成像在这些目标体上出现成像阴影.根据波场和Green函数的窗口Fourier框架展开,利用... 受地下复杂构造和地震数据采集系统的影响,使地震波对地下目标的照明出现不均匀性,地震采集系统难以有效地获取地下某些目标的反射信息,进而使数据偏移成像在这些目标体上出现成像阴影.根据波场和Green函数的窗口Fourier框架展开,利用角度域波动方程偏移成像和波动方程照明分析,并结合波动方程反演理论,提出一种角度域波动方程偏移成像阴影照明补偿方法.这种补偿方法能同时考虑地震数据采集系统和波场传播路径对偏移成像的影响,消除复杂构造区的偏移成像阴影,改进波动方程叠前深度偏移成像在复杂构造区的成像效果. 展开更多
关键词 波动方程 窗口Fourier框架展开 角度域 偏移成像阴影 照明分析 补偿
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基于目标区的局部角度域方向照明分析及其在偏移成像中的应用 被引量:6
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作者 耿瑜 毛剑 +1 位作者 吴如山 高静怀 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2012年第3期981-990,共10页
叠前深度偏移已成为近年来地震偏移成像领域广泛应用的技术之一,其中复杂盐丘下方目标区域结构的成像始终是偏移成像中较难解决的问题.局部角度域波场分解可以提供在空间和方向上的双重局部化信息,因而这一技术被广泛地应用在方向照明... 叠前深度偏移已成为近年来地震偏移成像领域广泛应用的技术之一,其中复杂盐丘下方目标区域结构的成像始终是偏移成像中较难解决的问题.局部角度域波场分解可以提供在空间和方向上的双重局部化信息,因而这一技术被广泛地应用在方向照明分析、成像振幅校正等方面.本文在采用局部指数标架小波束进行角度域方向照明分析的基础上,研究采集系统对复杂盐丘下部层状结构成像质量的影响;同时通过分析目标区对应于相对地表采集系统分布的照明能量,确定叠前炮集数据中对盐下目标区成像起重要贡献的部分,并将这些数据用来对目标区成像,从而达到提高盐下结构成像质量的目的.本文将二维SEG-EAGE盐丘模型中盐下反射体作为目标区,分别计算其照明分析和由照明能量分布确定的炮集数据对目标区的偏移成像结果,同时通过与成像振幅校正前后的成像结果对比,说明了该方法对提高目标区结构成像质量的有效性. 展开更多
关键词 局部指数标架 局部角度域 偏移成像 方向照明分析 采集孔径 目标区成像
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