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3D robust anisotropic diffusion filtering algorithm for sparse view neutron computed tomography 3D image reconstruction

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Nuclear Science and Techniques 2024年第3期35卷 13-29页

作者： Yang Liu teng-fei zhu zhi Luo Xiao-Ping Ouyang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Xi’an 710024China

The most critical part of a neutron computed tomography(NCT) system is the image processing algorithm,which directly affects the quality and speed of the reconstructed *** types of noise in the system can degrade the quality of the reconstructed ***,to improve the quality of the reconstructed images of NCT systems,efficient image processing algorithms must be *** anisotropic diffusion filtering(ADF) algorithm can not only effectively suppress the noise in the projection data,but also preserve the image edge structure information by reducing the diffusion at the image ***,we propose the application of the ADF algorithm for NCT image *** compare the performance of different algorithms in NCT systems,we reconstructed images using the ordered subset simultaneous algebraic reconstruction technique(OS-SART) algorithm with different regular terms as image processing *** the iterative reconstruction,we selected two image processing algorithms,the Total Variation and split Bregman solved total variation algorithms,for comparison with the performance of the ADF ***,the filtered back-projection algorithm was used for comparison with an iterative *** reconstructing the projection data of the numerical and clock models,we compared and analyzed the effects of each algorithm applied in the NCT *** on the reconstruction results,OS-SART-ADF outperformed the other algorithms in terms of denoising,preserving the edge structure,and suppressing *** example,when the 3D Shepp–Logan was reconstructed at 25 views,the root mean square error of OS-SART-ADF was the smallest among the four iterative algorithms,at only *** universal quality index,mean structural similarity,and correlation coefficient of the reconstructed image were the largest among all algorithms,with values of 0.9877,0.9878,and 0.9887,respectively.

关键词： NCT OS-SART Sparse-view Anisotropic diffusion filtering

Sparse-view neutron CT 3D image reconstruction algorithm based on split Bregman method

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Nuclear Science and Techniques 2024年第9期35卷 41-55页

作者： teng-fei zhu Yang Liu zhi Luo Xiao-Ping Ouyang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Xi’an 710024China

As a complement to X-ray computed tomography(CT),neutron tomography has been extensively used in nuclear engineer-ing,materials science,cultural heritage,and industrial *** of the attenuation matrix for neutron tomography with a traditional analytical algorithm requires hundreds of projection views in the range of 0°to 180°and typically takes several hours to *** a low time-resolved resolution degrades the quality of neutron *** the number of projection acquisitions is an important approach to improve the time resolution of images;however,this requires efficient reconstruction ***,sparse-view reconstruction algorithms in neutron tomography need to be *** this study,we investigated the three-dimensional reconstruction algorithm for sparse-view neu-tron CT *** enhance the reconstructed image quality of neutron CT,we propose an algorithm that uses OS-SART to reconstruct images and a split Bregman to solve for the total variation(SBTV).A comparative analysis of the performances of each reconstruction algorithm was performed using simulated and actual experimental *** to the analyzed results,OS-SART-SBTV is superior to the other algorithms in terms of denoising,suppressing artifacts,and preserving detailed structural information of images.

关键词： Neutron CT OS-SART Sparse-view 3D reconstruction Split Bregman Total variation

Variations and future projections of glacial discharge of Urumqi River Headwaters,eastern Tien Shan(1980s-2017)

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Advances in Climate Change Research 2024年第3期15卷 537-546页

作者： Hui zh.ng fei-teng WAng Ping zhOU Yi-Da XIE State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Key Laboratory of Cryospheric Science and Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China

To address data scarcity on long-term glacial discharge and inadequacies in simulating and predicting hydrological processes in the Tien Shan,this study analysed the observed discharge at multiple timescales over 1980se2017 and projected changes within a representative glacierized high-mountain region:eastern Tien Shan,Central *** processes were simulated to predict changes under four future scenarios(SSP1,SSP2,SSP3,and SSP5)using a classical hydrological model coupled with a glacier dynamics *** rates at annual,monthly(June,July,August)and daily timescales were obtained from two hydrological gauges:Urumqi Glacier No.1 hydrological station(UGH)and Zongkong station(ZK).Overall,annual and summer discharge increased significantly(png point in annual discharge at UGH may occur between 2018 and 2024 under the four SSPs *** discharge is predicted to cease earlier at ZK than at *** relates to glacier type and size,suggesting basins with heavily developed small glaciers will reach peak discharge sooner,resulting in an earlier freshwater supply *** findings serve as a reference for research into glacial runoff in Central Asia and provide a decision-making basis for planning local water-resource projects.

关键词： Observed glacial discharge Temporal variations Urumqi River Headwaters Eastern Tien Shan Simulation and projection

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

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Petroleum Science 2024年第3期21卷 1969-1979页

作者： Yang zh.ng Yong-An Li Xiang-Wei Kong Hao Liu teng-fei Sun College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100027China School of Petroleum Engineering Yangtze UniversityWuhan430000HubeiChina

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling *** mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is *** results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas *** temperature increases with the increase in BP and decreases in gas influx rate and wellbore *** gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the *** the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

Communication Resources Allocation for Time Delay Reduction of Frequency Regulation Service in High Renewable Penetrated Power System

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 468-480页

作者： Hongjie He Ning zh.ng Chongqing Kang Song Ci fei teng Goran Strbac State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Department of Electrical and Electronic Engineering Imperial College LondonSW72BULondonU.K

The high renewable penetrated power system has severe frequency regulation *** resources can provide frequency regulation services but are limited by com-munication time *** paper proposes a communication resources allocation model to reduce communication time delay in frequency regulation *** device resources and wireless spectrum resources are allocated to distributed resources when they participate in frequency *** reveal impact of communication resources allocation on time delay reduction and frequency regulation ***,we study communication resources allocation solution in high renewable energy penetrated power *** provide a case study based on the HRP-38 *** show communication time delay decreases distributed resources'ability to provide frequency regulation *** the other hand,allocating more communication resources to distributed resources'communica-tion services improves their frequency regulation *** power systems with renewable energy penetration above 70%,required communications resources are about five times as many as 30%renewable energy penetrated power systems to keep frequency performance the *** Terms-Communication resources allocation,commun-ication time delay,distributed resource,frequency regulation,high renewable energy penetrated power system.

关键词： Communication resources allocation communication time delay distributed resource frequency regulation high renewable energy penetrated power system

Prediction of fracture initiation in cohesive soils based on data mining modelling and large-scale laboratory verification

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Underground Space 2024年第6期19卷 279-300页

作者： Weiping Luo Dajun Yuan Yannick Choy Hing ng Dalong Jin Ping Lu teng Wang Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of the Ministry of Education for Urban Underground Engineering Beijing Jiaotong UniversityBeijing 100044China Department of Civil and Environmental Engineering National University of SingaporeSingapore 119077Singapore

Many empirical and analytical methods have been proposed to predict fracturing pressure in cohesive *** of them take into account three to four specific influencing factors and rely on the assumption of a failure *** this study,a novel data-mining approach based on the XGBoost algorithm is investigated for predicting fracture initiation in cohesive *** has the advantage of handling multiple influencing factors simultaneously,without pre-determining a failure mode.A dataset of 416 samples consisting of 14 distinct features was herein collected from past studies,and used for developing a regressor and a classifier model for fracturing pressure prediction and failure mode classification *** results show that the intrinsic characteristics of the soil govern the failure mode while the fracturing pressure is more sensitive to the stress *** XGBoost-based model was also tested against conventional approaches,as well as a similar machine learning algorithm namely random forest ***,several large-scale triaxial fracturing tests and an in-situ case study were carried out to further verify the generalization ability and applicability of the proposed data mining approach,and the results indicate a superior performance of the XGBoost model.

关键词： Fracturing pressure Failure mode Cohesive soil Data-mining Large-scale tests

Programmable synthetic receptors:the next-generation of cell and gene therapies

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Signal Transduction and Targeted Therapy 2024年第2期9卷 376-400页

作者： fei teng Tongtong Cui Li zhou Qingqin Gao Qi zhou Wei Li University of Chinese Academy of Sciences Beijing 101408China State Key Laboratory of Stem Cell and Regenerative Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Institute for Stem Cell and Regeneration Chinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China

Cell and gene therapies hold tremendous promise for treating a range of difficult-to-treat ***,concerns over the safety and efficacy require to be further addressed in order to realize their full *** receptors,a synthetic biology tool that can precisely control the function of therapeutic cells and genetic modules,have been rapidly developed and applied as a powerful *** designed and engineered,they can be applied to finetune the therapeutic activities,i.e.,to regulate production of dosed,bioactive payloads by sensing and processing user-defined signals or *** review provides an overview of diverse synthetic receptor systems being used to reprogram therapeutic cells and their wide applications in biomedical *** a special focus on four synthetic receptor systems at the forefront,including chimeric antigen receptors(CARs)and synthetic Notch(synNotch)receptors,we address the generalized strategies to design,construct and improve synthetic ***,we also highlight the expanding landscape of therapeutic applications of the synthetic receptor systems as well as current challenges in their clinical translation.

关键词： synthetic landscape payload

Experimental and simulation research on hollow AZ31 magnesium alloy three-channel joint by hot extrusion forming with sand mandrel

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Journal of Magnesium and Alloys 2024年第1期12卷 98-109页

作者： Shi Shengnan Wang Hongyu teng fei Jiang Lei Sun Juncai Sun Jie zh.ng Shunhu Transportation Engineering College Dalian Maritime UniversityDalianLiaoning 106026China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyangLiaoning 110819China Shagang School of Iron and Steel Soochow UniversitySuzhouJiangsu 215021China

Magnesium alloy is one of the lightest metal structural *** weight is further reduced through the hollow ***,the hollow structure is easily damaged during *** order to maintain the hollow structure and to transfer the stresses during the high temperature deformation,the sand mandrel is *** this paper,the hollow AZ31 magnesium alloy three-channel joint is studied by hot extrusion *** as one of solid granule medium is used to fill the hollow magnesium *** extrusion temperatures are 230℃ and 300℃,*** process parameters(die angle,temperature,bottom thickness,sidewall thickness,edge-to-middle ratio in bottom,bottom shape)of the hollow magnesium alloy are analyzed based on the results of experiments and the finite element *** results are shown that the formability of the hollow magnesium alloy will be much better when the ratio of sidewall thickness to the bottom thickness is 1:*** when edge-to-middle ratio in bottom is about 1:1.5,a better forming product can be *** best bottom shape in these experiments will be convex based on the forming *** grain will be refined obviously after the *** the microstructures will be shown as *** these lines will be well agreement with the mold in the corner.

关键词： AZ31 magnesium alloy Three-channel joint Sand Experiments and the finite element Die angle

Water structures and anisotropic dynamics at Pt(211)/water interface revealed by machine learning molecular dynamics

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Materials Futures 2024年第4期3卷 1-10页

作者： fei-teng Wang Xiandong Liu Jun Cheng State Key Laboratory of Physical Chemistry of Solid Surfaces iChEMCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005People’s Republic of China State Key Laboratory for Mineral Deposits Research School of Earth Sciences and EngineeringNanjing UniversityNanjingJiangsu 210023People’s Republic of China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjingJiangsu 210023People’s Republic of China Laboratory of AI for Electrochemistry(AI4EC) IKKEMXiamen 361005People’s Republic of China Institute of Artificial Intelligence Xiamen UniversityXiamen 361005People’s Republic of China

Water molecules at solid–liquid interfaces play a pivotal role in governing interfacial phenomena that underpin electrochemical and catalytic *** organization and behavior of these interfacial water molecules can significantly influence the solvation of ions,the adsorption of reactants,and the kinetics of electrochemical *** stepped structure of Pt surfaces can alter the properties of the interfacial water,thereby modulating the interfacial environment and the resulting surface *** the in situ details of water structures at these stepped Pt/water interfaces is crucial for understanding the fundamental mechanisms that drive diverse applications in energy conversion and material *** this work,we have developed a machine learning potential for the Pt(211)/water interface and performed machine learning molecular dynamics *** findings reveal distinct types of chemisorbed and physisorbed water molecules within the adsorbed ***,we identified three unique water pairs that were not observed in the basal plane/water interfaces,which may serve as key precursors for water *** interfacial water structures contribute to the anisotropic dynamics of the adsorbed water *** study provides molecular-level insights into the anisotropic nature of water behavior at stepped Pt/water interfaces,which can influence the reorientation and distribution of intermediates,molecules,and ions—crucial aspects for understanding electrochemical and catalytic processes.

关键词： machine learning molecular dynamics stepped Pt/water interfaces anisotropic water dynamics