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In-situ measurement via the flow-through method and numerical simulations for radon exhalation during measurements of the radon exhalation rate

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Nuclear Science and Techniques 2024年第7期35卷 192-207页

作者： Ming Xia Yong-jun Ye Shan-Wei Shang Ting Yu Dai-Jia {1. school of Resources Environment and Safety {1. University of South ChinaHengyang421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang421001China

Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two *** abnormal radon exhalation behavior was observed,leading to computational fluid dynamics(CFD)-based simulations in which dynamic radon migration in a porous medium and accumulation chamber was *** on the in-situ experimental and numerical simulation results,variations in the radon exhalation rate subject to permeability,flow rate,and insertion depth were quantified and *** in-situ radon exhalation rates measured using the flow-through method were higher than those measured using the closed-loop method,which could be explained by the negative pressure difference between the inside and outside of the chamber during the *** consistency of the variations in the radon exhalation rate between the experiments and simulations suggests the reliability of CFD-based techniques in obtaining the dynamic evolution of transient radon exhalation rates for diffusion and convection at the porous medium-air *** synergistic effects of the three factors(insertion depth,flow rate,and permeability)on the negative pressure difference and measured exhalation rate were quantified,and multivariate regression models were established,with positive correlations in most cases;the exhalation rate decreased with increasing insertion depth at a permeability of 1.10^(−1.) m^(2).CFD-based simulations can provide theoretical guidance for improving the flow-through method and thus achieve accurate measurements.

关键词： Radon exhalation Flow-through Numerical simulation Accumulation chamber Multivariate regression

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Characteristics and origin of low-organicmatter carbonate source rocks in the Middle-Upper Ordovician, Tarim Basin, northwestern China

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Journal of Palaeogeography 2024年第3期13卷 594-619页

作者： jun-Qing {1. Fu-Jie Jiang Xiong-Qi Pang Hai-jun Yang Kan-Yuan Shi Bo Pang Hong Pang Jian-Fa {1. Zhuo-Heng {1. Xin-Gang Zhang Song Wu State Key Laboratory of Petroleum Resources and engineering China University of Petroleum(Beijing)Beijing 102249China Basic Research Center for Energy Interdisciplinary College of ScienceChina University of Petroleum(Beijing)Beijing 102249China Beijing Key Laboratory of Optical Detection Technology for Oil and Gas China University of Petroleum(Beijing)Beijing 102249China College of Geosciences China University of Petroleum(Beijing)Beijing 102249China Research Institute of Petroleum Exploration and Development PetroChina Tarim Oilfield CompanyKorla 841000Xinjiang Uygur Autonomous RegionChina Geological Survey of Canada Natural Resources CanadaCalgary T2L 2A7Canada

The continually-discovered large volumes of marine hydrocarbons indicate a huge exploration potential within the carbonate rocks of Ordovician in the Tarim Basin,northwestern *** Middle-Upper Ordovician(O2+3)carbonate source rocks are at a highly mature *** rocks presently contain a low amount of total organic carbon(TOC_(pd)≤0.5%)(TOC_(pd) means the present-day TOC).A mass balance approach is used to identify the source rocks that have expelled *** characteristics and origin of hydrocarbon expulsion from low-TOC_(pd) source rocks are studied,which are significant for oil exploration in the *** results showed that a low-TOC_(pd) O2+3 source rock having expelled hydrocarbons was type I and had a very narrow oil *** a high rock maturity and a high original TOC(TOCo)value exceeding 1.,nearly 80%of the generated hydrocarbons were *** content of gammacerane and C28 steranes in the oil and source rock extracts were relatively lean,with a V-shaped distribution of regular steranes,suggesting a possible genetic relation between the low-TOC_(pd) source rocks and the marine oil in the Tabei *** planktonic algae or acritarchs were the main hydrocarbon parent materials,distributed in the subsiding platform-slope *** matter was preserved under reducing conditions,and source rocks were formed with a favorable kerogen type and a moderate hydrocarbon generation *** study illustrates the hydrocarbon expulsion of low TOC_(pd) source rocks in northern Tarim Basin,which is greatly significant for analyzing the genesis of marine crude oil in Tarim Basin,and evaluating the distribution of marine source *** research method is theoretically significant for oil and gas exploration in the same type of highlymature carbonate paleobasins.

关键词： Carbonate source rock Mass balance approach Present-day TOC Genesis mechanism Tarim Basin

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Parallel Driving with Big Models and Foundation Intelligence in Cyber-hysical-ocial Spaces

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Research 2024年第2期2024卷 1-17页

作者： Xiao Wang jun Huang Yonglin Tian {1. Sun Lie Yang Shanhe Lou {1. Lv Changyin Sun Fei-Yue Wang school of Artificial Intelligence Anhui UniversityHefeiChina Macao University of Science and Technology MacaoChina State Key Laboratory for Management and Control of Complex Systems Institute of AutomationChinese Academy of SciencesBeijingChina MVSLab Department of Mechanical and Mechatronics EngineeringUniversity of Waterloo200 University Ave WestWaterlooON N2L3G1Canada school of Mechanical and Aerospace {1. Nanyang Technological UniversitySingaporeSingapore

Recent years have witnessed numerous technical breakthroughs in connected and autonomous vehicles (CAVs). On the one hand, these breakthroughs have significantly advanced the development of intelligent transportation systems (ITSs);on the other hand, these new traffic participants introduce more complex and uncertain elements to ITSs from the social space. Digital twins (DTs) provide real-time, data-driven, precise modeling for constructing the digital mapping of physical-world ITSs. Meanwhile, the metaverse integrates emerging technologies such as virtual reality/mixed reality, artificial intelligence, and DTs to model and explore how to realize improved sustainability, increased efficiency, and enhanced safety. More recently, as a leading effort toward general artificial intelligence, the concept of foundation model was proposed and has achieved significant success, showing great potential to lay the cornerstone for diverse artificial intelligence applications across different domains. In this article, we explore the big models embodied foundation intelligence for parallel driving in cyber-physical-social spaces, which integrate metaverse and DTs to construct a parallel training space for CAVs, and present a comprehensive elucidation of the crucial characteristics and operational mechanisms. Beyond providing the infrastructure and foundation intelligence of big models for parallel driving, this article also discusses future trends and potential research directions, and the ?S?goals of parallel driving.

关键词： breakthrough integrate corners

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Quantifying freeze-melt dynamics of lakes on the Tibetan Plateau using Sentinel-1.synthetic aperture radar imagery

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Journal of Mountain Science 2024年第3期21卷 805-819页

作者： JIN Lu chen {1. CAI Yu KONG Yecheng WANG Yongfeng DUAN Zheng school of Environment and Energy {1. Anhui Jianzhu UniversityHefei 230601China Anhui engineering and Technology Research Center for Smart City Anhui Jianzhu UniversityHefei 230601China school of Geographic and Oceanographic Sciences Nanjing UniversityNanjing 210023China Department of Physical Geography and Ecosystem Science Lund UniversityLund 22362Sweden

The ice phenology of alpine lakes on the Tibetan Plateau(TP)is a rapid and direct responder to climate changes,and the variations in lake ice exhibit high temporal frequency *** and passive microwave data are widely used to monitor lake ice changes with high temporal ***,the low spatial resolutions make it difficult to effectively quantify the freeze-melt dynamics of *** work used Sentinel-1.synthetic aperture radar(SAR)data to derive high-resolution ice maps(about 6 days),then with the aid of Sentinel-2 optical images to quantify freeze-melt processes in three typical lakes on the TP(*** Co,Ayakekumu Lake,and Nam Co).The results showed that three lakes had an average annual ice period of 1.5-1.7 days and a complete ice cover period of 72-1.5 days,from 201. to *** exhibit different ice phenology *** Co is characterized by repeated episodes of freezing,melting,and refreezing,resulting in a prolonged freeze-up ***,the break-up period of Nam Co lasts for a longer duration(about 1. days),and the break-up exhibits a smooth ***,Ayakekumu Lake showed more significant inter-annual fluctuations in the freeze-up period,with deviations of up to 28 days observed among different *** to the other two lakes,Selin Co experienced a relatively short freeze-up and break-up *** short,Sentinel-1.SAR data can effectively monitor the weekly and seasonal variations in lake ice on the ***,this data facilitates quantification of the freeze-melt dynamics.

关键词： Lake ice Sentinel-1 SAR Tibetan Plateau Climate change

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Cerium oxide inclusion nucleation mechanism based on classical nucleation theory and two-step nucleation

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Journal of Rare Earths 2024年第4期42卷 793-802页

作者： Yutang Li jun Wang Linzhu Wang Chaoyi {1. Shufeng Yang junqi Li Xiang Li school of Materials and Metallurgy Guizhou UniversityGuiyang550025China State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025China school of Metallurgical and Ecological {1. University of Science and Technology BeijingBeijing100083China Department of Materials&Metallurgy engineering Guizhou Institute of TechnologyGuiyang550003China

It is challenging to assess the mechanism responsible for the nucleation of inclusions in metals at high *** present work therefore systematically investigates the nucleation of cerium oxide inclusions according to classical nucleation theory and a two-step nucleation *** nucleation rates and nucleation radii of these inclusions are obtained,and the results demonstrate a considerable difference between theoretical and experimental *** the basis of a two-step nucleation mechanism,(CeO_(2))_(n) and(Ce_(2)O_(3))_(n)(n=1.6)clusters were constructed and the thermodynamic properties of both these clusters and of cerium oxide nanoparticles were *** addition,the entropies and heat capacity changes of cerium oxides were determined using first principles calculations and are found to be consistent with literature *** present data indicate that the cerium oxide inclusion nucleation pathway can be summarized as[Ce]+[O]→(CeO_(2))n/(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(2)→core(Ce_(2)O_(3)crystal)-shell((Ce_(2)O_(3))_(2) cluster)nanoparticles→(Ce_(2)O_(3))bulk.

关键词： Cerium oxide inclusion Classical nucleation theory Two-step nucleation mechanism First principles Rare earths

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Intake of tobacco nitrosamines of smokers in various provinces of China and their cancer risk:A meta-analysis

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Journal of Environmental Sciences 2024年第7期141卷 249-260页

作者： Xiao Li Zhiwei Ye jun Wang Pengfei Lin Xiaojin Zhang Shuguang Xie Chao {1. Research Institute for Environmental Innovation(Suzhou) TsinghuaSuzhouJiangsu 215163China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Shenzhen Key Laboratory of Organic Pollution Prevention and Control State Key Laboratory of Urban Water Resource and EnvironmentHarbin Institute of TechnologyShenzhen 518055China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Science and EngineeringPeking UniversityBeijing 100871China

Nitrosamines are a class of carcinogens which have been detected widely in food,water,some pharmaceuticals as well as *** objectives of this paper include reviewing the basic information on tobacco consumption and nitrosamine contents,and assessing the health risks of tobacco nitrosamines exposure to Chinese *** searched the publications in English from“Web of Science”and those in Chinese from the“China National Knowledge Infrastructure”in 2022 and collected 1.1 literatures with valid *** content of main nitrosamines in tobacco,including 4-(methylnitrosoamino)-1.(3-pyridyl)-1.butanone(NNK),N-nitrosonornicotine(NNN),N-nitrosoanatabine(NAT),N-nitrosoanabasine(NAB),total tobacco-specific nitrosamines(TSNA),and N-nitrosodimethylamine(NDMA)were *** information of daily tobacco consumption of smokers in 30 provinces of China was also ***,the intakes of NNN,NNK,NAT,NAB,TSNAs,and NDMA via tobacco smoke were estimated as 1.34ng/day,591.ng/day,685 ng/day,81.ng/day,2543 ng/day,and 484 ng/day by adult smokers in30 provinces,*** cancer risk(CR)values for NNN and NNK inhalation intake were further calculated as 1.44×1.^(-5)and 1.95×1.^(-4).The CR value for NDMA intake via tobacco smoke(inhalation:1.66×1.^(-4))indicates that NDMA is similarly dangerous in tobacco smoke when compared with the *** China,the CR values caused by average nitrosamines intake via various exposures and their order can be estimated as the following:smoke(3.75×1.^(-4))>food(1.74×1.^(-4))>drinking water(1.38×1.^(-5)).Smokers in China averagely suffer 200%of extra cancer risk caused by nitrosamines in tobacco when compared with non-smokers.

关键词： N-nitrosamine Tobacco Cancer risk Tobacco specific nitrosamines(TSNAs) N-nitrosodimethylamine(NDMA)

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Aggregation of CeAlO_(3) inclusions in heavy ingot of a steel containing 0.007% aluminum

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Journal of Iron and Steel Research International 2024年第8期31卷 1960-1972页

作者： Qiu-yue Zhou jun-tao Ba Lun Zhang Wei {1. Ying Ren Li-feng Zhang school of Metallurgical and Ecological {1. University of Science and Technology BeijingBeijing 100083China school of Mechanical {1. Yanshan UniversityQinhuangdao 066004HebeiChina school of Mechanical and Materials {1. North China University of TechnologyBeijing 100144China

The distribution of inclusions at the bottom of a Ce-treated heavy steel ingot was detected and *** three-dimensional morphology and spatial distribution of CeAlOs clusters were characterized using the electrolytic extraction and Micro-CT detection.A model of inclusion collision to predict the aggregation of CeAlO_(3) inclusions in the ingot was established and validated by measured *** were mainly CeAlO_(3) and a small amount of Ce_(2)O_(2)S in the tundish after cerium *** collision and aggregation of inclusions led to the formation of large clusters in the ingot during the solidification *** slag entrainment inclusions,large CeAO_(3) clusters and small CeAlO_(3) particles were observed from the center to the edge of the ingot *** inclusions were mainly concentrated at the *** number density of inclusions larger than 200μm was 0.21.mm^(-3).The maximum diameter of CeA1._(3) clusters was 1.40μ*** the edge to the radial center and from the bottom to the top,the average diameter of inclusions gradually increased due to the longer solidification time of the ingot.

关键词： Inclusion Heavy ingot Cerium treatment Collision

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Design and optimization of torsion harvester of Lycium barbarum L.

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International Journal of Agricultural and Biological engineering 2024年第4期17卷 109-115页

作者： Qingyu chen Shixia Zhang Naishuo Wei Puhang Li Guangrui Hu {1. chen Yu chen College of Mechanical and electronic {1. Northwest A&F UniversityYangling 712100ShaanxiChina

The production of Lycium barbarum *** a labor-intensive *** manual harvests are required during the harvesting season,which contributes to the high harvesting *** cultivation conditions of *** were investigated to increase efficiency and mitigate harvesting damage.A torsion harvester was designed according to the characteristic of infinite inflorescence and the distribution of detachment force,and the kinematics model of the harvester was *** vibration responses of ripe and unripe fruit were obtained through ADAMS simulation of the branch model,and the influencing factors and value range of the torsion harvester were also *** mathematical models of ripe fruit harvesting rate,unripe fruit harvesting rate,ripe fruit damage rate and torsion angle,vibration rods distance,and vibration frequency were established by the Box-Behnken *** influences of various factors on ripe fruit harvesting rate,unripe fruit harvesting rate,and ripe fruit damage rate were analyzed,and the best parameter combination was obtained:torsion angle 73.66°,vibration rods distance 35.51.mm and vibration frequency 1..1. *** experiment showed that the harvesting rate of ripe fruit is 95.67%,the harvesting rate of unripe fruit is 4.68%,and the damage rate of ripe fruit is 3.70%.The research results can promote the mechanization process of *** harvest,and provide a reference for vibration harvest of berries.

关键词： L.barbarum vibrating torsion response surface method parameters optimization ADAMS RSM

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Locating Sources of Oscillations Induced by Control of Voltage Source Converters Based on Energy Structure and Nonlinearity Detection

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1285-1294页

作者： Zetian Zheng Shaowei Huang jun Yan Qiangsheng Bu {1. Shen Mingzhong Zheng Ye Liu State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China State Grid Jiangsu Electric Power Co. Ltd.Research InstituteNanjing 211103China

The oscillation phenomena associated with the con-trol of voltage source converters(VSCs)are concerning,mak-ing it crucial to locate the sources of such oscillations and sup-press the ***,this paper presents a location scheme based on the energy structure and nonlinearity *** energy structure,which conforms to the principle of the energy-based method and dissipativity theory,is developed to describe the transient energy flow for VSCs,based on which a defined characteristic quantity is implemented to narrow the scope for locating the sources of ***,based on the self-sustained oscillation characteristics of VsCs,an in-dex for nonlinearity detection is applied to locate the VSCs that produce the oscillation *** combination of the energy structure and nonlinearity detection distinguishes the contribu-tions of different VSCs to the *** results of a case study implemented by the PSCAD/EMTDC simulation validate theproposed scheme.

关键词： Double-loop proportional-integral(PI)control energy structure Hamiltonian model nonlinearity detection oscillation source location(OSL) voltage source converter(VSC)

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FIBTNet:Building Change Detection for Remote Sensing Images Using Feature Interactive Bi-Temporal Network

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Computers, Materials & Continua 2024年第9期80卷 4621-4641页

作者： Jing Wang Tianwen Lin chen Zhang {1. Peng school of Geographic Information and Tourism Chuzhou UniversityChuzhou239000China Anhui Province Key Laboratory of Physical Geographic Environment Chuzhou UniversityChuzhou239000China

In this paper,a feature interactive bi-temporal change detection network(FIBTNet)is designed to solve the problem of pseudo change in remote sensing image building change *** network improves the accuracy of change detection through bi-temporal feature *** designs a bi-temporal feature exchange architecture(EXA)and a bi-temporal difference extraction architecture(DFA).EXA improves the feature exchange ability of the model encoding process through multiple space,channel or hybrid feature exchange methods,while DFA uses the change residual(CR)module to improve the ability of the model decoding process to extract different features at multiple ***,at the junction of encoder and decoder,channel exchange is combined with the CR module to achieve an adaptive channel exchange,which further improves the decision-making performance of model feature *** results on the LEVIR-CD and S2Looking datasets demonstrate that iCDNet achieves superior F1.scores,Intersection over Union(IoU),and Recall compared to mainstream building change detectionmodels,confirming its effectiveness and superiority in the field of remote sensing image change detection.

关键词： Change detection change residual module feature exchange mechanism feature fusion

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