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Simultaneous fluorescence and Compton scattering computed tomography based on linear polarization X-ray

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-10页

作者： Chi, Zhi-Jun Zhang, Hong-Ze Lin, Jin Zhang, Xuan-Qi Ding, Hao Tian, Qi-Li Zhang, Zhi Du, Ying-Chao Huang, Wen-Hui Tang, Chuan-Xiang beijing Normal univ Sch Phys & Astron Minist Educ Key Lab Beam Technol Beijing 100875 Peoples R China Tsinghua univ Minist Educ Dept Engn Phys Key Lab Particle & Radiat Imaging Beijing 100084 Peoples R China

PurposeTo propose a method for simultaneous fluorescence and Compton scattering computed tomography by using linearly polarized *** Carlo simulations were adopted to demonstrate the feasibility of the proposed method. In the simulations, the phantom is a polytetrafluoroethylene cylinder inside which are cylindrical columns containing aluminum, water, and gold (Au)-loaded water solutions with Au concentrations ranging between 0.5 and 4.0 wt%, and a parallel-hole collimator imaging geometry was adopted. The light source was modeled based on a Thomson scattering X-ray source. The phantom images for both imaging modalities were reconstructed using a maximumlikelihood expectation maximization *** the X-ray fluorescence computed tomography (XFCT) and Compton scattering computed tomography (CSCT) images of the phantom were accurately reconstructed. A similar attenuation contrast problem for the different cylindrical columns in the phantom can be resolved in the XFCT and CSCT images. The interplay between XFCT and CSCT was analyzed, and the contrast-to-noise ratio (CNR) of the reconstruction was improved by correcting for the mutual influence between the two imaging modalities. Compared with K-edge subtraction imaging, XFCT exhibits a CNR advantage for the *** XFCT and CSCT can be realized by using linearly polarized X-rays. The synergy between the two imaging modalities would have an important application in cancer radiation therapy

关键词： X-ray fluorescence computed tomography Compton scattering computed tomography Linear polarization Thomson scattering X-ray source Monte Carlo simulation DUAL-ENERGY CT NANOPARTICLE-LOADED OBJECTS ATTENUATION COEFFICIENTS XFCT PARAMETRIZATION FEASIBILITY ELEMENTS

Seismic risk assessment and damage analysis: Emerging trends and new developments

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JOURNAL OF SAFETY SCIENCE AND RESILIENCE 2024年第3期5卷 365-381页

作者： Liu, Yi Gu, Yin Zhang, Hui Tsinghua univ Inst Publ Safety Res Dept Engn Phys Beijing 100084 Peoples R China Tsinghua univ Sch Safety Sci Beijing 100084 Peoples R China beijing Key Lab City Integrated Emergency Response Beijing 100084 Peoples R China

Earthquakes are major catastrophes that cause great life and economic losses to human society and environment. This paper reviews and synthesizes relevant studies, drawing from a systematic examination of 4229 articles from the Web of Science core collection (1982-2023). Employing the CiteSpace visualization and analysis tool, current research and emerging trends in seismic risk assessment are discussed and analyzed. This paper provides a holistic overview of principal contributions, knowledge sources, interdisciplinary characteristics, and principal research topics in this field. Additionally, we propose key technologies that are in urgent need of enhancement, including data availability, quantity and quality of data, interpretability of machine learning models, performance improvement of machine learning methods and application of foundation models, as well as real-time risk assessment techniques. These insights support both theoretical understanding and practical applications of seismic risk assessment and damage analysis.

关键词： Earthquake Vulnerability Seismic risk assessment Seismic damage analysis CiteSpace HISTORICAL MASONRY TOWERS VULNERABILITY ASSESSMENT FRAGILITY CURVES TYPICAL BRIDGES RESILIENCE EARTHQUAKE MODEL FRAMEWORK BUILDINGS NETWORK

Hydrocarbon Generation Potential and Organic Matter Enrichment Mechanism of the Cambrian Marine Shale in the Tadong Low Uplift, Tarim Basin

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ACTA GEOLOGICA SINICA-ENGLISH EDITION 2024年第5期98卷 1301-1321页

作者： Miao, Huan Wang, Yanbin Jiang, Zhenxue Zhao, Shihu Shang, Peng Gong, Xun Tao, Chuanqi Zhang, Yu China univ Petr Natl Key Lab Petr Resources & Engn Beijing 102249 Peoples R China China univ Petr Unconvent Oil & Gas Sci & Technol Res Inst Beijing 102249 Peoples R China China univ Min & Technol Coll Geosci & Surveying Engn Beijing 100083 Peoples R China SINOPEC Petr Explorat & Prod Res Inst Beijing 102206 Peoples R China PetroChina Changqing Oilfield Co Gas Prod Plant 2 Yulin 719000 Shaanxi Peoples R China Peking univ Sch Earth & Space Sci Beijing 100871 Peoples R China Liaoning Petrochem univ Sch Civil Engn Fushun 113001 Liaoning Peoples R China

Cambrian shales in China and elsewhere contain abundant oil and gas resources. However, due to its deep burial and limited outcrop, there has been relatively little research conducted on it. The Cambrian shale of the Tadong low uplift in the Tarim Basin of western China, specifically the Xidashan-Xishanbulake Formation (Fm.) and overlying Moheershan Fm. provide a case study through the use of organic petrology, mineralogy, organic and elemental geochemistry, with the aim of analyzing and exploring the hydrocarbon generation potential (PG) and organic matter (OM) enrichment mechanisms within these shale formations. The results indicate that: (1) the Cambrian shale of the Tadong low uplift exhibits relatively dispersed OM that consists of vitrinite-like macerals and solid bitumen. These formations have a higher content of quartz and are primarily composed of silica-based lithology; (2) shale samples from the Xidashan-Xishanbulake and Moheershan formations demonstrate high total organic carbon (TOC) and low S-2 content. The OM is predominantly type I and type II kerogens, indicating a high level of maturation in the wet gas period. These shales have undergone extensive hydrocarbon generation, showing characteristics of relatively poor PG; (3) the sedimentary environments of the Xidashan-Xishanbulake and Moheershan formations in the Tadong low uplift are similar. They were deposited in warm and humid climatic conditions, in oxygen-deficient environments, with stable terrigenous inputs, high paleoproductivity, high paleosalinity, weak water-holding capacity, and no significant hydrothermal activity; and (4) the relationship between TOC and the paleoproductivity parameter (P/Ti) is most significant in the Lower Cambrian Xidashan-Xishanbulake Fm., whereas correlation with other indicators is not evident. This suggests a productivity-driven OM enrichment model, where input of land-derived material was relatively small during the Middle Cambrian, and the ancient water exhibi

关键词： Conventional resources hydrocarbon generation potential geochemistry sedimentary environment enrichment mechanism organic matter Cambrian Tadong low uplift SOUTH CHINA CONSTRAINTS SOURCE-ROCK EVALUATION TURPAN-HAMI BASIN GEOCHEMICAL CHARACTERISTICS BLACK SHALES RARE-EARTH NW CHINA LOWER ORDOVICIAN SILICEOUS ROCKS TRACE-ELEMENTS

Research on physical explosion crater model of high-pressure natural gas pipeline

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PETROLEUM RESEARCH 2024年第3期9卷 432-438页

作者： Wang, Dongyuan Xu, Shuiying Wang, Zhao Zhou, Yazhe Gao, Na China Petr Pipeline engn Corp Langfang Peoples R China PipeChina engn Technol Innovat Co Ltd Tianjin Peoples R China univ Sci & Technol beijing Sch Civil & Resource Engn Beijing Peoples R China China Petr Pipeline Bur engn Co Ltd Int Business Dept Langfang Peoples R China

In this study, Hypermesh and LS-DYNA numerical simulation software are used to build a multi domain coupling model of natural gas pipeline, including soil, pipeline, TNT explosive and air domain, and the non-reflection boundary conditions are set for the model. The TNT equivalent method is used to convert the physical explosion amount of natural gas pipeline into 1387.38 kg TNT explosive amount. The simulation results show that the physical explosion of pipeline forms an approximate elliptical crater with a width of 12.68 m and a depth of 4.12 m; the TNT equivalent of the model is corrected by comparing the crater simulation value and the size value of the crater calculated by the PRCI empirical formula under the same laying condition, and the correction coefficient is selected as 0.9, and the corrected TNT equivalent is 1248.64 kg; the modified model crater size is 3.72 m deep and 12.66 m wide, compared with the crater size obtained from the field test, the error of crater depth and width calculated by the modified model simulation is 5.7% and 15.5% respectively. (c) 2024 The Authors. Publishing services provided by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://***/licenses/ by-nc-nd/4.0/).

关键词： High-pressure natural gas Pipeline Physical explosion Crater Numerical simulation

Prediction of (n, 2n) reaction cross-sections of long-lived fission products based on tensor model

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-14页

作者： Huang, Jia-Li Wang, Hui Huang, Ying-Ge Xiao, Er-Xi Feng, Yu-Jie Lei, Xin Gu, Fu-Chang Zhu, Long Chen, Yong-Jing Su, Jun Sun Yat Sen univ Sino French Inst Nucl Engn & Technol Zhuhai 519082 Peoples R China China Inst Atom Energy Key Lab Nucl Data Beijing 102413 Peoples R China China Inst Atom Energy China Nucl Data Ctr Beijing 102413 Peoples R China

Interest has recently emerged in potential applications of (n, 2n) reactions of unstable nuclei. Challenges have arisen because of the scarcity of experimental cross-sectional data. This study aims to predict the (n, 2n) reaction cross-section of long-lived fission products based on a tensor model. This tensor model is an extension of the collaborative filtering algorithm used for nuclear data. It is based on tensor decomposition and completion to predict (n, 2n) reaction cross-sections; the corresponding EXFOR data are applied as training data. The reliability of the proposed tensor model was validated by comparing the calculations with data from EXFOR and different databases. Predictions were made for long-lived fission products such as 60Co, 79Se\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{79}} {\mathrm{Se}}$$\end{document}, 93Zr\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{93}}\mathrm{Zr}$$\end{document}, 107P\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{107}}\mathrm{P}$$\end{document}, 126Sn\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{126}}\mathrm{Sn}$$\end{document}, and 137Cs\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepack

关键词： (n, 2n) Reaction cross-section Tensor model Machine learning Collaborative filtering algorithm Selective transmutation NUCLEAR-DATA TRANSMUTATION N,2N

Dynamic Characteristics of the Long Runout Rock-ice Avalanche at High Altitude-A Case from the Zelongnong Basin, Eastern Himalayan Syntaxis, China

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ACTA GEOLOGICA SINICA-ENGLISH EDITION 2024年第5期98卷 1376-1393页

作者： Gao, Shaohua Yin, Yueping Li, Bin Gao, Yang Zhang, Nan Zhang, Tiantian Gao, Haoyuan Liu, Xiaojie Chinese Acad Geol Sci Inst Geomech Beijing 100081 Peoples R China China Inst Geol Environm Monitoring Beijing 100081 Peoples R China Minist Nat Resources Key Lab Act Tecton & Geol Safety Beijing 100081 Peoples R China Lanzhou univ Technol Sch Civil Engn Lanzhou 730050 Peoples R China

Rock-ice avalanches have frequently occurred in the Eastern Himalayan Syntaxis region due to climate change and active tectonic movements. These events commonly trigger catastrophic geohazard chains, including debris flows, river blockages, and floods. This study focuses on the Zelongnong Basin, analyzing the geomorphic and dynamic characteristics of high-altitude disasters. The basin exhibits typical vertical zonation, with disaster sources initiating at elevations exceeding 4000 m and runout distances reaching up to 10 km. The disaster chain movement involves complex dynamic effects, including impact disintegration, soil-rock mixture arching, dynamic erosion, and debris deposition, enhancing understanding of the flow behavior and dynamic characteristics of rock-ice avalanches. The presence of ice significantly increases mobility due to lubrication and frictional melting. In the disaster event of September 10, 2020, the maximum flow velocity and thickness reached 40 m/s and 43 m, respectively. Furthermore, continuous deformation of the Zelongnong glacier moraine was observed, with maximum cumulative deformations of 44.68 m in the distance direction and 25.96 m in the azimuth direction from March 25, 2022, to August 25, 2022. In the future, the risk of rock-ice avalanches in the Eastern Himalayan Syntaxis region will remain extremely high, necessitating a focus on early warning and risk mitigation strategies for such basin disasters.

关键词： rock-ice avalanche dynamic characteristics mobility moraine Eastern Himalayan Syntaxis FREEZE-THAW CYCLES LANDSLIDE FRAGMENTATION ROCKSLIDE GLACIERS FAILURE FLOOD

Research on slim-hole drilling technology for shale gas geological survey in China

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PETROLEUM RESEARCH 2024年第3期9卷 451-461页

作者： Zhao, Hongbo Wu, Haixia Shen, Lina Zhu, Zhitong Shan, Yansheng China Geol Survey Oil & Gas Survey Beijing 100083 Peoples R China beijing Inst Explorat engn Beijing 100083 Peoples R China Chinese Acad Geol Sci Inst Explorat Tech Langfang 065000 Peoples R China

Over the last 10 years, the China Geological Survey has deployed 137 slim-hole shale gas geological exploration wells for coring entire wellbores. These wells are primarily located in new blocks and geological formations where neighboring well data are insufficient, beyond the scope of developed oil fields in China, or outside of oil and gas company mining-right areas. The drilling rig equipment, coring tools, and core drill bits of slim-hole shale gas drilling technology are different from those associated with traditional petroleum drilling. Many studies have been conducted on non-coring slim-hole drilling technology. This paper focuses on coring technology and drilling safety, summarizing a set of high- efficiency shale gas drilling equipment and technology systems based on geological drilling equipment and techniques (that can be used for solid mineral exploration). We report on: 1) an improved vertical shaft drilling rig adapted to shale gas well control safety; 2) high-efficiency core drilling techniques, focusing on coring tools, and techniques incorporating an inverted tower drilling tool combination, air circulation follow-through technology, and expanded casing technology; 3) research progress on high- efficiency core drill bits, including non-planar tooth polycrystalline diamond compact bits and impregnated diamond core bits, along with their application effects. This research provides substantial advances in drill-core technology and improvements in exploration efficiency. Moreover, it provides a reference frame for well structural design and selection of construction technology for shale gas exploration drilling projects. (c) 2024 The Authors. Publishing services provided by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY-NC-ND license .

关键词： Shale gas Slim-hole drilling technology Core drilling tools Core drill bits China RESEARCH PROGRESS EXPLORATION DISCOVERY

Research on perturbation of neutron fluence rate in a closed thermal neutron field due to medium materials

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-11页

作者： Yang, Jun-Kai Wang, Ping-Quan Hu, Zhi-Meng Li, Fan Zeng, Jun-Mei Xiao, Lin Guo, Hong-Yu Zhang, Jian Gorini, Giuseppe Zhang, Hui Chu, Chungming Paul Nanjing univ Coll Engn & Appl Sci Nanjing 210093 Peoples R China Natl Inst Metrol Beijing 100029 Peoples R China Nanjing univ Aeronaut & Astronaut Dept Nucl Sci & Technol Nanjing 210093 Peoples R China univ Milano Bicocca Dept Phys I-20126 Milan Italy

The neutron radiation field has vital applications in areas such as biomedicine, geology, radiation safety, and many others for neutron detection and neutron metrology. Correcting neutron fluence rate perturbation accurately is an important yet challenging problem. This study proposes a correction method that analyzes three physical processes. This method, which transforms the detection process from point detection to area detection, is based on a novel physical model and has been validated through theoretical analyses, experiments, and simulations. According to the average differences between the calculated and experimental results, the new method (1.67%) demonstrated better accuracy than the traditional simulation (2.17%). In a closed thermal neutron radiation field, the detector or strong neutron absorption material significantly perturbs the neutron fluence rate, whereas its impact on the energy spectrum shape and neutron directionality is relatively minor. Furthermore, based on the calculation results of the perturbation rate formula for medium materials with different compositions and sizes, the larger the volume and capture cross section of the medium, the higher the perturbation rate generated in the closed radiation field.

关键词： Perturbation rate Area detection Three-dimensional neutron energy spectrum Closed radiation field INFINITE-PLANE ABSORBERS FLUX PERTURBATIONS SPECTRUM

In-beam gamma rays of CSNS Back-n characterized by black resonance filter

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-12页

作者： Wang, Jin-Cheng Ren, Jie Jiang, Wei Ruan, Xi-Chao Liu, Ying-Yi Yang, Hao-Lan Xu, Kuo-Zhi Pan, Xin-Yi Sun, Qi Bao, Jie Huang, Han-Xiong Bai, Hao-Fan Bai, Jiang-Bo Cao, Ping Chen, Qi-Ping Chen, Yong-Hao Duan, Wen-Hao Fan, An-Chuan Fan, Rui-Rui Feng, Chang-Qing Gu, Min-Hao Han, Chang-Cai Han, Zi-Jie He, Guo-Zhu He, Yong-Cheng Hong, Yang Hu, Yi-Wei Jiang, Zhi-Jie Kang, Ling Lan, Chang-Lin Li, Bo Li, Feng Li, Qiang Li, Xiao Li, Yang Liu, Jie Liu, Rong Liu, Shu-Bin Liu, Yi-Na Luan, Guang-Yuan Ning, Chang-Jun Qiu, Yi-Jia Ren, Wen-Kai Ren, Zhi-Zhou Song, Zhao-Hui Sun, Kang Tan, Zhi-Xin Tang, Jing-Yu Tang, Sheng-Da Wang, Li-Jiao Wang, Peng-Cheng Wang, Zhao-Hui Wen, Zhong-Wei Wu, Xiao-Guang Wu, Xuan Wu, Ze-Peng Xia, Cong Xie, Li-Kun Yi, Han Yu, Tao Yu, Yong-Ji Zhang, Guo-Hui Zhang, Hang-Chang Zhang, Qi-Wei Zhang, Xian-Peng Zhang, Yu-Liang Zhang, Zhi-Yong Zhao, Mao-Yuan Zhou, Zhi-Hao Zhu, Ke-Jun Zou, Chong China Inst Atom Energy Key Lab Nucl Data Beijing 102413 Peoples R China Chinese Acad Sci Inst High Energy Phys Beijing 100049 Peoples R China Spallat Neutron Source Sci Ctr Dongguan 523803 Peoples R China Chinese Acad Sci Inst High Energy Phys State Key Lab Particle Detect & Elect Beijing 100049 Peoples R China univ Chinese Acad Sci Beijing 100049 Peoples R China Peking univ Sch Phys State Key Lab Nucl Phys & Technol Beijing 100871 Peoples R China Fudan univ Inst Modern Phys Shanghai 200433 Peoples R China univ Sci & Technol China State Key Lab Particle Detect & Elect Hefei 230026 Peoples R China univ Sci & Technol China Sch Nucl Sci & Technol Hefei 230026 Peoples R China univ Sci & Technol China Dept Modern Phys Hefei 230026 Peoples R China China Acad engn Phys Inst Nucl Phys & Chem Mianyang 621900 Peoples R China univ Sci & Technol China USTC Archaeometry Lab Hefei 230026 Peoples R China Northwest Inst Nucl Technol Xian 710024 Peoples R China Lanzhou univ Sch Nucl Sci & Technol Lanzhou 730000 Peoples R China univ Sci & Technol China Inst Adv Technol Hefei 230027 Peoples R China

The back-streaming white-neutron beamline (Back-n) of the China Spallation Neutron Source is an essential neutron- research platform built for the study of nuclear data, neutron physics, and neutron applications. Many types of cross-sectional neutron-reaction measurements have been performed at Back-n since early 2018. These measurements have shown that a significant number of gamma rays can be transmitted to the experimental stations of Back-n along with the neutron beam. These gamma rays, commonly referred to as in-beam gamma rays, can induce a non-negligible experimental background in neutron-reaction measurements. Studying the characteristics of in-beam gamma rays is important for understanding the experimental background. However, measuring in-beam gamma rays is challenging because most gamma-ray detectors are sensitive to neutrons; thus, discriminating between neutron-induced signals and those from in-beam gamma rays is difficult. In this study, we propose the use of the black resonance filter method and a CeBr3 scintillation detector to measure the characteristics of the in-beam gamma rays of Back-n. Four types of black resonance filters, Ta-181, Co-59, Ag-nat, and Cd-nat, were used in this measurement. The time-of-flight (TOF) technique was used to select the detector signals remaining in the absorption region of the TOF spectra, which were mainly induced by in-beam gamma rays. The energy distribution and flux of the in-beam gamma rays of Back-n were determined by analyzing the deposited energy spectra of the CeBr3 scintillation detector and using Monte Carlo simulations. Based on the results of this study, the background contributions from in-beam gamma rays in neutron-reaction measurements at Back-n can be reasonably evaluated, which is beneficial for enhancing both the experimental methodology and data analysis.

关键词： In-beam gamma rays Back-n Black filter resonance technique In-beam gamma rays Back-n CeBr3 scintillator Black filter resonance technique C6D6 DETECTOR SYSTEM LINE