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Design and performance evaluation of a large field-of-view dual-particle time-encoded imager based on a depth-of-interaction detector

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Nuclear Science and Techniques 2024年第4期35卷 1-14页

作者： Dong Zhao Xu-wen Liang ping-Kun Cai Wei Cheng wen-Bao Jia Da-Qian Hei Qing Shan Yong-Sheng Ling Chao shi Department of Nuclear Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211106China Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions Suzhou 215000China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Time-encoded imaging is useful for identifying potential special nuclear materials and other radioactive sources at a *** this study,a large field-of-view time-encoded imager was developed for gamma-ray and neutron source hotspot imaging based on a depth-of-interaction(DOI)*** imager primarily consists of a DOI detector system and a rotary dual-layer cylindrical coded *** EJ276 plastic scintillator coupled with two SiPMs was designed as the DOI detector to increase the field of view and improve the imager *** difference in signal time at both ends and the log of the signal amplitude ratio were used to calculate the interaction position *** position resolution of the DOI detector was calibrated using a collimated Cs-137 source,and the full width at half maximum of the reconstruction position of the Gaussian fitting curve was approximately 4.4 *** DOI detector can be arbitrarily divided into several units to independently reconstruct the source distribution *** unit length was optimized via Am-Be source-location experiments.A multidetector filtering method is proposed for image *** method can effectively reduce image noise caused by poor DOI detector position *** vertical field of view of the imager was(-55°,55°)when the detector was placed in the center of the coded mask.A DT neutron source at 20 m standoff could be located within 2400 s with an angular resolution of 3.5°.

关键词： Time-encoded imager Depth-of-interaction detector Dual-particle imaging Hotspot imaging

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A Fuzzy Trust Management Mechanism with Dynamic Behavior Monitoring for Wireless Sensor Networks

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China Communications 2024年第5期21卷 177-189页

作者： Fu shiming Zhang ping shi Xuehong School of Artificial Intelligence Chongqing University of EducationChongqing 400065China School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Traditional wireless sensor networks(WSNs)are typically deployed in remote and hostile environments for information *** wireless communication methods adopted by sensor nodes may make the network highly vulnerable to various *** encryption and authentication mechanisms cannot prevent attacks launched by internal malicious *** trust-based security mechanism is usually adopted to solve this problem in ***,the behavioral evidence used for trust estimation presents some uncertainties due to the open wireless medium and the inexpensive sensor ***,how to efficiently collect behavioral evidences are rarely *** address these issues,in this paper,we present a trust management mechanism based on fuzzy logic and a cloud ***,a type-II fuzzy logic system is used to preprocess the behavioral evidences and alleviate ***,the cloud model is introduced to estimate the trust values for sensor ***,a dynamic behavior monitoring protocol is proposed to provide a balance between energy conservation and safety *** results demonstrate that our trust management mechanism can effectively protect the network from internal malicious attacks while enhancing the energy efficiency of behavior monitoring.

关键词： behavior monitoring cloud fuzzy trust wireless sensor networks

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CMAGAN:classifier-aided minority augmentation generative adversarial networks for industrial imbalanced data and its application to fault prediction

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Advances in Manufacturing 2024年第3期12卷 603-618页

作者： wen-Jie Wang Zhao Liu ping Zhu School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China National Engineering Research Center of Automotive Power and Intelligent Control Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China School of Design Shanghai Jiao Tong UniversityShanghai200240People’s Republic of China

Class imbalance is a common characteristic of industrial data that adversely affects industrial data mining because it leads to the biased training of machine learning *** address this issue,the augmentation of samples in minority classes based on generative adversarial networks(GANs)has been demonstrated as an effective *** study proposes a novel GAN-based minority class augmentation approach named classifier-aided minority augmentation generative adversarial network(CMAGAN).In the CMAGAN framework,an outlier elimination strategy is first applied to each class to minimize the negative impacts of ***,a newly designed boundary-strengthening learning GAN(BSLGAN)is employed to generate additional samples for minority *** incorporating a supplementary classifier and innovative training mechanisms,the BSLGAN focuses on learning the distribution of samples near classification ***,it can fully capture the characteristics of the target class and generate highly realistic samples with clear ***,the new samples are filtered based on the Mahalanobis distance to ensure that they are within the desired *** evaluate the effectiveness of the proposed approach,CMAGAN was used to solve the class imbalance problem in eight real-world fault-prediction *** performance of CMAGAN was compared with that of seven other algorithms,including state-of-the-art GAN-based methods,and the results indicated that CMAGAN could provide higher-quality augmented results.

关键词： Class imbalance Minority class augmentation Generative adversarial network(GAN) Boundary strengthening learning(BSL) Fault prediction

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A tectono-thermal perspective on the petroleum generation,accumulation and preservation in the southern Ordos Basin, North China

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Petroleum Science 2024年第3期21卷 1459-1473页

作者： Peng Yang Zhan-Li Ren Jin-Hua Fu Hong-ping Bao Hui Xiao Zheng shi Kun Wang Yuan-Yuan Zhang wen-Hui Liu wen-Hou Li State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an710069ShanxiChina National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields Exploration and Development Research Institute of PetroChina Changqing Oilfield CompanyXi'an710018ShaanxiChina Shaanxi Key Lab of Petroleum Accumulation Geology School of Earth Science and EngineeringXi'an Shiyou UniversityXian710065ShaanxiChina Wuxi Research Institute of Petroleum Geology Petroleum Exploration and Production Research InstituteSINOPECWuxi214126JiangsuChina

The southern Ordos Basin has excellent petroleum exploration ***,the tectono-thermal history and the controls on petroleum generation,accumulation and preservation conditions in southern basin are *** this study,we analyzed the present geothermal field,paleo-geothermal gradient,maturity of the hydrocarbon source rocks,uplift and cooling process and tectono-thermal evolution *** the study area,for the Ordovician,Permain and the Triassic strata,the present temperature is low(3070℃)in the southeastern area but high(80140℃)in the northwestern *** paleogeothermal gradient varied from 24℃/km to 30℃/km with a heat flow of 58—69 m W/m^(2)(i.e.,a medium-temperature basin).The paleo-temperatures are higher than the present temperatures and the maximum paleo-temperatures controlled the thermal maturity of the source *** vitrinite reflectance(Ro)values of the Triassic strata are>0.7%and the thermal maturity reached the middlemature oil generation *** Rovalues of the Permian-Ordovician strata are>1.8%and the thermal maturity reached the over-mature gas generation *** southern Ordos Basin has experienced the multiple tectonic events at the Late Ordovician Caledonian(452 Ma),Late Triassic(215 Ma),Late Jurassic(165160 Ma),End-Early Cretaceous(110100 Ma)and Cenozoic(since 40 Ma).A large-scale tectonothermal event occurred at the End-Early Cretaceous(110100 Ma),which was controlled by lithospheric extension,destruction and *** event led to the highest paleo-temperatures and thermal maturities and coeval with the peak period of petroleum generation and *** southern Ordos Basin has undergone rapid and large-scale uplift since the Late Cretaceous due to expansion of the northeastern margin of the Tibetan Plateau,uplift of the Qinling orogenic belt and thrust faulting in the Liupanshan tectonic *** southern Ordos Basin experienced tectonic overprinting that was strong in the south and weak in the *** str

关键词： Fission-track dating Vitrinitereflectance Geothermal field Tectono-thermal evolution Petroleum geology Ordos Basin

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Fixed-Time Gradient Flows for Solving Constrained Optimization: A Unified Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第8期11卷 1849-1864页

作者： Xinli shi Xiangping Xu Guanghui wen Jinde Cao School of Cyber Science and Engineering Southeast UniversityNanjing 210096China School of Mathematics Southeast UniversityNanjing 210096China

The accelerated method in solving optimization problems has always been an absorbing *** on the fixedtime(FxT)stability of nonlinear dynamical systems,we provide a unified approach for designing FxT gradient flows(FxTGFs).First,a general class of nonlinear functions in designing FxTGFs is provided.A unified method for designing first-order FxTGFs is shown under Polyak-Łjasiewicz inequality assumption,a weaker condition than strong *** there exist both bounded and vanishing disturbances in the gradient flow,a specific class of nonsmooth robust FxTGFs with disturbance rejection is *** the strict convexity assumption,Newton-based FxTGFs is given and further extended to solve time-varying ***,the proposed FxTGFs are further used for solving equation-constrained ***,an FxT proximal gradient flow with a wide range of parameters is provided for solving nonsmooth composite *** show the effectiveness of various FxTGFs,the static regret analyses for several typical FxTGFs are also provided in ***,the proposed FxTGFs are applied to solve two network problems,i.e.,the network consensus problem and solving a system linear equations,respectively,from the perspective of ***,by choosing component-wisely sign-preserving functions,these problems can be solved in a distributed way,which extends the existing *** accelerated convergence and robustness of the proposed FxTGFs are validated in several numerical examples stemming from practical applications.

关键词： Consensus constrained optimization disturbance rejection linear equations fixed-time gradient flow(FxTGF).

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Optimal Cooperative Secondary Control for Islanded DC Microgrids via a Fully Actuated Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 405-417页

作者： Yi Yu Guo-ping Liu Yi Huang Peng shi IEEE Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and TechnologyShenzhen 518055China School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China School of Electrical and Mechanical Engineering the University of AdelaideSA 5005Australia Research and Innovation Centre Obuda University1034 BudapestHungary

DC-DC converter-based multi-bus DC microgrids(MGs) in series have received much attention, where the conflict between voltage recovery and current balancing has been a hot topic. The lack of models that accurately portray the electrical characteristics of actual MGs while is controller design-friendly has kept the issue active. To this end, this paper establishes a large-signal model containing the comprehensive dynamical behavior of the DC MGs based on the theory of high-order fully actuated systems, and proposes distributed optimal control based on this. The proposed secondary control method can achieve the two goals of voltage recovery and current sharing for multi-bus DC MGs. Additionally, the simple structure of the proposed approach is similar to one based on droop control, which allows this control technique to be easily implemented in a variety of modern microgrids with different configurations. In contrast to existing studies, the process of controller design in this paper is closely tied to the actual dynamics of the MGs. It is a prominent feature that enables engineers to customize the performance metrics of the system. In addition, the analysis of the stability of the closed-loop DC microgrid system, as well as the optimality and consensus of current sharing are given. Finally, a scaled-down solar and battery-based microgrid prototype with maximum power point tracking controller is developed in the laboratory to experimentally test the efficacy of the proposed control method.

关键词： DC microgrids distributed control high-order fully actuated system approach linear quadratic regulator microgrid modeling secondary control

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Damping capacity of Fe_(83)Ga_(17) magnetostrictive alloy under magnetic field

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Rare Metals 2024年第1期43卷 402-409页

作者： Shao-wen Yan Xing Mu Bing-Jie Liu Li-Hong Xu shi-Hai Guo Yan Qi Hong-ping Zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China

The damping performance of Fe_(83)Ga_(17) alloys has been investigated in the static magnetic field (H). The results demonstrate that the damping peak value can be adjusted between 0.020 and 0.085 under the magnetic f... 详细信息

关键词： alloy magnetic alloys

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Regulated polarization degree of upconversion luminescence and multiple anti-counterfeit applications

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Rare Metals 2024年第5期43卷 2172-2183页

作者： Dong-ping wen ping Chen Yi Liang Xiao-Ming Mo Cao-Feng Pan Center On Nanoenergy Research Guangxi Key Laboratory for Relativistic AstrophysicsSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China Key Laboratory of Micronano Energy and Sensor CAS Center for Excellence in NanoscienceBeijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijing 100140China

Polarization upconversion luminescence(PUCL)of lanthanide ions(Ln^(3+))has been widely used in single particle tracking,microfluidics detection,three-dimensional displays,and so ***,no effective strategy has been developed for modulating *** we report a strategy to regulate PUCL in Ho^(3+)-doped NaYF4single nanorods based on the number of upconversion *** constructing a multiphoton upconversion system for Ho^(3+),we regulate the degree of polarization(DOP)of PUCL from 0.590 for two-photon luminescence to 0.929 for three-photon upconversion luminescence(UCL).Furthermore,our strategy is verified from cross-relaxation between Ho^(3+)and Yb^(3+),excitation wavelength,excitation power density,and local site *** this regulation strategy of PUCL has also been achieved in Tm^(3+),with the DOP ranging from 0.233 for two-photon luminescence to 0.925 for four-photon UCL Besides,multi-dimensional anti-counterfeiting display has been explored with *** work provides an effective strategy for regulating PUCL and also provides more opportunities for the development of polarization display optical encoding,anti-counterfeiting,and integrated optical devices.

关键词： Polarization upconversion luminescence Degree of polarization Population density of excited state Number of upconversion photons Polarization anti-counterfeitingdisplay

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Study of inter-well interference in shale gas reservoirs by a robust production data analysis method based on deconvolution

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Petroleum Science 2024年第4期21卷 2502-2519页

作者： wen-Chao Liu Cheng-Cheng Qiao ping Wang wen-Song Huang Xiang-wen Kong Yu-ping Sun He-Dong Sun Yue-Peng Jia School of Civil and Resource Engineering University of Science and Technology Beijing PetroChina Research Institute of Petroleum Exploration and Development

In order to overcome the defects that the analysis of multi-well typical curves of shale gas reservoirs is rarely applied to engineering, this study proposes a robust production data analysis method based on deconvolution, which is used for multi-well inter-well interference research. In this study, a multi-well conceptual trilinear seepage model for multi-stage fractured horizontal wells was established, and its Laplace solutions under two different outer boundary conditions were obtained. Then, an improved pressure deconvolution algorithm was used to normalize the scattered production data. Furthermore, the typical curve fitting was carried out using the production data and the seepage model solution. Finally,some reservoir parameters and fracturing parameters were interpreted, and the intensity of inter-well interference was compared. The effectiveness of the method was verified by analyzing the production dynamic data of six shale gas wells in Duvernay area. The results showed that the fitting effect of typical curves was greatly improved due to the mutual restriction between deconvolution calculation parameter debugging and seepage model parameter debugging. Besides, by using the morphological characteristics of the log-log typical curves and the time corresponding to the intersection point of the log-log typical curves of two models under different outer boundary conditions, the strength of the interference between wells on the same well platform was well judged. This work can provide a reference for the optimization of well spacing and hydraulic fracturing measures for shale gas wells.

关键词： Shale gas Inter-well interference Deconvolution Production data analysis Typical curves Multi-stage fractured horizontal well

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Imaging of human parafoveal area with large field of view in adaptive optics line scanning ophthalmoscope

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Journal of Innovative Optical Health Sciences 2024年第6期17卷 41-51页

作者： wen Kong Yiwei Chen Guohua shi Yi He Department of Biomedical Engineering University of Science and Technology of ChinaHefei 230041P.R.China Jiangsu Key Laboratory of Medical Optics Suzhou Institute of Biomedical Engineering and TechnologyChinese Academy of SciencesSuzhou 215163P.R.China Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of SciencesShanghai 200031P.R.China Key Laboratory of Myopia of State Health Ministry and Key Laboratory of Visual Impairment and Restoration of ShanghaiShanghai 200003P.R.China

The parafoveal area,with its high concentration of photoreceptors andfine retinal capillaries,is crucial for central vision and often exhibits early signs of pathological *** current adaptive optics scanning laser ophthalmoscope(AOSLO)provides an excellent tool to acquire accurate and detailed information about the parafoveal area with cellular ***,limited by the scanning speed of two-dimensional scanning,thefield of view(FOV)in the AOSLO system was usually less than or equal to 2,and the stitching for the parafoveal area required dozens of images,which was time-consuming and ***,almost half of patients are unable to obtain stitched images because of their *** solve this problem,we integrate AO technology with the line-scan imaging method to build an adaptive optics line scanning ophthalmoscope(AOLSO)system with a larger *** the AOLSO,afocal spherical mirrors in pairs are nonplanar arranged and the distance and angle between optical elements are optimized to minimize the aberrations,two cylinder lenses are orthogonally placed before the imaging sensor to stretch the point spread function(PSF)for su±ciently digitizing light *** human retinal images show the whole parafoveal area with 55FOV,60 Hz frame rate and cellular *** advantage of the 5FOV of the AOLSO,only 9 frames of the retina are captured with several minutes to stitch a montage image with an FOV of 99,in which photoreceptor counting is performed within approximately 5*** AOLSO system not only provides cellular resolution but also has the capability to capture the parafoveal region in a single frame,which offers great potential for noninvasive studying of the parafoveal area.

关键词： Adaptive optics line scanning retinal imaging system parafoveal capillary vasculature.

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