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Properties Improvement of Polyethylene Wax-Wrapped Tungsten Carbide/High-Density Polyethylene Γ-Ray Shielding Composites Through Irradiation-Induced Crosslinking

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SSRN 2024年

作者： Qian, Bingbing Dai, Yaodong Xin, Lingfei Yao, Chuqing Wang, Guohui College of Material Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing211106 China The 404 Company Limited. CNNC Gansu Prov Lanzhou735100 China Key Laboratory of Nuclear Fuel Cycle Technology Gansu Prov 735100 China Chengdu Nuclear Engineering Design &Research Institute Co. Ltd. CNNC 404 Sichuan Prov 610000 China

It is well known that the properties of polyethylene can be improved by crosslinking the formation of three-dimensional network structures. This paper investigated the effects of gamma irradiation and irradiation atmosphere on the properties of polyethylene wax-wrapped tungsten carbide (WC-PEW)/high-density polyethylene γ-ray shielding composites. The obtained fracture surface of the unirradiated composites with or without polyethylene wax (PEW) illustrated that WC-PEW had better compatibility with high-density polyethylene. The gel content analysis found the maximum to be 95% with TAIC-containing γ-ray shielding composites (HDPE/WC-PEW/TAIC) under 50 kGy irradiation in vacuum when compared to all composites, under the same irradiation conditions, the tensile strength of HDPE/WC-PEW/TAIC were 29.49 MPa, and the thermal stability of WC-PEW is also the best improved. When the content of the WC was 50% and the thickness of the HDPE/WC-PEW/TAIC was 2 mm, the γ-ray shielding rates for 137Cs energy at 662 keV, 60Co energies at 1170 and 1330 keV can reach 52.19%, 26.98% and 27.30%, respectively. In summary, the improvement of the properties of HDPE/WC-PEW/TAIC is most significant in the irradiation of 50 kGy in vacuum, and has high potential to replace lead-containing composites as multifunctional γ-ray shielding material for commercial utilization. © 2024, The Authors. All rights reserved.

关键词： Gamma rays

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Study on cosmogenic radioactive production in germanium as a background for future rare event search experiments

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nuclear Science and Techniques 2020年第6期31卷 22-29页

作者： Yu-Lu Yan Wei-Xin Zhong Shin-Ted Lin Jing-Jun Zhu Chen-Kai Qiao Lei Zhang Yu Liu Qian Yue Hao-Yang Xing Shu-Kui Liu College of Physics Sichuan UniversityChengdu 610064China School of Physics Nankai UniversityTianjin 30071China Institute of Nuclear Science and Technology Sichuan UniversityChengdu 610065China Department of Engineering Physics Tsinghua UniversityBeijing 100084China

Rare event search experiments are one of the most important topics in the field of fundamental physics,and high-purity germanium(HPGe)detectors with an ultralow radioactive background are frequently used for such ***,cosmogenic activation contaminates germanium crystals during transport and *** this study,we investigated the movable shielding containers of HPGe crystals using Geant4 and CRY Monte Carlo *** production rates of 68Ge,65Zn,60Co,55Fe,and 3H were obtained individually for different types of cosmic *** validity of the simulation was confirmed through a comparison with the available experimental *** on this simulation,we found that the interactions induced by neutrons contribute to approximately 90%of the production rate of cosmogenic *** addition,by adding an optimized shielding structure,the production rates of cosmogenic radionuclides are reduced by about one order of *** results show that it is feasible to use a shielding container to reduce the cosmogenic radioactivity produced during the transport and storage of high-purity germanium on the ground.

关键词： High-purity germanium Shielding structure Geant4 Transportation

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The complementary role of carbon dioxide removal: A catalyst for advancing the COP28 pledges towards the 1.5 °C Paris Agreement target

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Science of the Total Environment 2024年 947卷 174302页

作者： Acen, Caroline Bamisile, Olusola Cai, Dongsheng Ukwuoma, Chiagoziem C. Obiora, Sandra Huang, Qi Uzun Ozsahin, Dilber Adun, Humphrey College of Nuclear Science and Automation Engineering Sichuan Industrial Internet Intelligent Monitoring and Application Research Center Chengdu University of Technology Sichuan Chengdu China Centre for Environmental Policy Imperial College London United Kingdom Leeds Business School Leeds Beckett University LeedsLS1 3HE United Kingdom Electrical Engineering Department Southwest University of Science and Technology Sichuan Maiyang China Department of Medical Diagnostic Imaging College of Health Science University of Sharjah Sharjah United Arab Emirates Research Institute for Medical and Health Sciences University of Sharjah Sharjah United Arab Emirates Operational Research Centre in Healthcare Near East University TRNC Nicosia Mersin 1099138 Turkey Energy and Environmental Science Division University of Dundee Scotland United Kingdom

As the imperative to address climate change becomes more pressing, there is an increasing focus on limiting global temperature increase to 1.5 °C by the end of the century relative to pre-industrial levels. During the recent Conference of Parties (COP28), nations committed to tripling renewable energy generation to a minimum of 11,000 GW by 2030 and increasing the global annual energy efficiency from 2 % to 4 % annually until 2030. Additionally, the Food and Agricultural Organization (FAO) introduced a roadmap to transition the Agri-food system from a net emitter to a carbon sink. The role of carbon dioxide removal (CDR) is important;first to accelerate the near-term reduction in net emissions, counterbalance residual emissions at the point of net-zero by mid-century, and sustain large net negative emissions beyond mid-century to return warming to safe levels after decades of temporal overshoot. This paper assesses the impact of the COP 28 agreements, alongside the complementary role of CDR on emission levels, energy structure, land use, and global warming temperature. The findings indicate that implementing the COP28 pledges and FAO roadmap leads to a warming temperature of 2 °C, falling short of the ambitious 1.5 °C temperature limit. Likewise, more stringent actions on transitioning away from fossil plants is a high-priority mitigation action which drives significant emissions reduction. The modelled result shows that Agricultural soil carbon and biochar contribute 47–58 % share of the total CDR deployed in the stylized scenarios. In conclusion, CDR can expedite climate goals but must complement emission reduction efforts;hence, the transition away from fossil fuels should prompt the development of detailed roadmaps. Also, more global efforts should be placed on nature-based CDR methods, as they offer diverse co-benefits. © 2024 Elsevier B.V.

关键词： Global warming

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Properties Improvement of Polyethylene Wax-Wrapped Tungsten Carbide/High-Density Polyethylene Γ-Ray Shielding Composites Through Irradiation-Induced Crosslinking

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SSRN 2024年

作者： Qian, Bingbing Dai, Yaodong Xin, Lingfei Yao, Chuqing Wang, Guohui College of Material Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing211106 China The 404 Company Limited. CNNC Gansu Prov Lanzhou735100 China Key Laboratory of Nuclear Fuel Cycle Technology Gansu Prov 735100 China Chengdu Nuclear Engineering Design & Research Institute Co. Ltd. CNNC 404 Sichuan Prov 610000 China

关键词： Gamma rays

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Knowledge System,Ontology,and Knowledge Graph of the Deep-Time Digital Earth(DDE): Progress and Perspective

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Journal of Earth Science 2023年第5期34卷 1323-1327页

作者： Xiumian Hu Yiwei Xu Xiaogang Ma Yunqiang Zhu Chao Ma Chao Li Hairong Lü Xinbing Wang Chenghu Zhou Chengshan Wang School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China Department of Computer Science University of IdahoMoscow ID 83844USA Institute of Geographical Science and Natural Resources Chinese Academy of SciencesBeijing 100101China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation&Institute of Sedimentary Geology&College of Computer Science and Cyber Security Chengdu University of TechnologyChengdu 610059China IUGS Deep-Time Digital Earth Research Center of Excellence Suzhou 215101China Department of Automation Tsinghua UniversityBeijing 100084China School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China

THE USE OF KNOWLEDGE GRAPH IN NATURAL SCIENCE Knowledge graph is a field of Artificial Intelligence(AI)that aims to represent knowledge in the form of graphs,consisting of nodes and edges which represent entities and relationships between nodes respectively(Aidan et al.,2022).Although the knowledge graph was popularized recently due to use of this idea in Google’s search engine in 2012(Amit,2012),its root can be traced back to the emergence of the Semantic Web as well as earlier works in ontology(Aggarwal,2021).

关键词： DDE Google Web Semantic

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A Novel Chain Multi-UAV Communication Relay Maintenance Control

A Novel Chain Multi-UAV Communication Relay Maintenance Cont...

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International Conference on Wavelet Active Media technology and Information Processing (ICWAMTIP)

作者： Tao Cancan Zhan Yiao Zhang Jiancheng Zhang Pengyu Zhao Xin Yu Yaowei School of Automation Science and Electrical Engineering Beihang University Beijing China School of Astronautics Harbin Institute of Technology Harbin China School of Mathematics and Physics & Center for Applied Mathematics of Guangxi Guangxi Minzu University Nanning China School of Mechatronic Engineering and Automation Shanghai University Shanghai China School of Mechanical and Electrical Engineering Hohai University Changzhou China College of Civil Aviation Nanjing University of Aeronautics and Astronautics Nanjing China

ISBN: (数字)9798331519254

ISBN: (纸本)9798331519261

To ensure real-time feedback of the observation information from the remote tracking UAV, multiple UAVs are used to construct a communication relay chain between the tracking UAV and the ground base station. The problem is decomposed into two sub-problems: (1) initial communication relay formation; (2) continuous communication relay maintenance. For the former, a simultaneous arrival algorithm based on the Dubins curve is proposed to form the initial configuration of multi-UAV cooperative communication maintenance; for the latter, considering constraints such as platform performance, communication constraints, collision avoidance, etc., a distributed nonlinear model predictive control algorithm is used to dynamically optimize the control inputs of each UAV, achieving continuous maintenance of multi-UAV collaborative communication. The simulation results have verified the feasibility and effectiveness of the proposed method.

关键词： Target tracking Heuristic algorithms Simulation Collaboration Autonomous aerial vehicles Prediction algorithms Turning Maintenance Relays Predictive control

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Leveraging technology for Virtual Class and Learning during COVID-19 Pandemic

Leveraging Technology for Virtual Class and Learning during ...

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2021 IEEE International Conference on Educational technology, ICET 2021

作者： Yin, Xiaohua Hossin, Md Altab Sarker, Md Nazirul Islam Leng, Jing School of Automation Engineering University of Electronic Science and Technology of China Chengdu China School of Management and Economics University of Electronic Science and Technology of China Chengdu China School of Political Science and Public Administration Neijiang Normal University Neijiang China Tianfu New Area Aviation Tourism College Administration Office Meishan China

ISBN: (纸本)9780738112572

Online or virtual learning is a prominent educational method that takes place over the Internet as a form of distance education. Distance education has become substantially popular as a result of the COVID-19 pandemic in 2020. Virtual learning can play a key role in an emergency period like the COVID-19 pandemic because most of the learners have access to information and communication technologies (ICT). So, leveraging technology in education can be a potential solution in learning. This study intends to examine how digital technology can be integrated effectively for better learning and education during the COVID-19 pandemic. A systematic literature review was performed using the Scopus database from 2001 to 2020. According to inclusion criteria, 26 studies were selected for qualitative analysis. In particular, four forms of technology-oriented learning systems have been revealed: electronic (e-learning), mobile (m-learning), interactive (i-learning), and ubiquitous learning (u-learning). The introduction of technology into the teaching-learning process can be an important way of developing improved learning and educational outcomes for learners and educators. In this paper, the learning models provided have the ability to exploit the associated technologies to ensure the feedback and delivery of the learning approach. The research will provide educators, teachers, policymakers, and curriculum creators with a new lens to design a better learning strategy for the learner. © 2021 IEEE.

关键词： COVID-19

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Bubble Detection and Identification Based on the Vibration Response for the Sodium Water Reaction

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SSRN 2023年

作者： Qin, Min Su, Dong Wang, Yong Peng, Shiqi Wang, Yao Zheng, Zhao Liu, Zhiguo Deng, Yongjun Southwest University of Science and Technology China Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province Southwest University of Science and Technology Mianyang621010 China Laser Fusion Research Center China Academy of Engineering Physics Mianyang621000 China Metrology and Testing Center China Academy of Engineering Physics Mianyang621000 China Nuclear Power Institute of China Chengdu610000 China College of Nuclear Science and Technology Beijing Normal University Beijing100875 China

Real-time bubble behavior characterization and localization are critical in the chemical industry, especially for leakage of sodium-water reactions. In this paper, the characteristics of bubble signals excited by gas injection and sodium water reaction were investigated by the vibration method. Specifically, the time-frequency and energy characteristics of bubble signals were studied by vibration response. The bubble signals excited by the two kinds of experiments have the same characteristic frequency band of 200-400 Hz, and the maximum energy is obtained at 250 Hz. The bubble signal from the sodium-water reaction can be effectively recognized by identifying the differences in the characteristics of multiple parameters when the gas injection rate is 0.07 m3/h with a signal-to-noise ratio of 11.8-17.1 dB. On the basis of energy analysis of the bubble signal, a bubble signal source location method based on time domain statistics was proposed, and the trajectory curve of the bubble signal excited by the sodium water reaction in the initial 600 ms was successfully obtained with an error rate less than 5%. Comparative analysis indicates that kurtosis was more sensitive for bubble signal recognition, while the Root Mean Square (RMS) and Standard Deviation (SD) values were more suitable for bubble positioning. Thus, this study complemented the present techniques and knowledge for bubble identification and localization in multiphase flow engineering. © 2023, The Authors. All rights reserved.

关键词： Chemical industry

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Atmospheric Two-Way Time Transfer over Kilometers Free-Space Link with Dual Optical Frequency Comb

Atmospheric Two-Way Time Transfer over Kilometers Free-Space...

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International Conference on Communication technology (ICCT)

作者： Wantao Huang Changfeng Chen Dong Hou College of Science Kaili University Kaili China Science and Technology on Electronic Information Control Laboratory Southwest China Research Institute of Electronic Equipment Chengdu China School of Automation Engineering University of Electronic Science and Technology of China Chengdu China

In this paper, we report an outdoor free space optical two-way time transfer technique with dual optical frequency comb (OFC). Using the transfer method, we transmitted the pulse time signal on the kilometer-level free space link. In the time transfer experiment, the time drift and time deviation of 1 km and 20 km links are measured and simulated respectively. The experimental results show that the total root mean square (RMS) time drift of 1-km link is about 2.2 ps within 5000 seconds, the time deviation is 2 ps when the average time is 1 second, and the time deviation is 0.32 ps when the average time is 100 s. The emulation estimates that the RMS time drift of a 20 km link is about 232 ps within 5000 seconds, the time deviation is 115 ps when the average time is 1 second, and the time deviation is 36 ps when the average time above 100 s.

关键词： Integrated optics Time-frequency analysis Emulation Optical harmonic generation Time measurement Optical fiber communication Communications technology

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Theoretical Study on the Macroscopic Thermodynamic Properties of Beh+ and Ch+

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SSRN 2024年

作者： Hu, Minli Xu, Zhihao Fan, Qunchao Fan, Zhixiang Li, Huidong Fu, Jia Wu, Jizhou Ma, Jie Xie, Feng School of Science Key Laboratory of High Performance Scientific Computation Xihua University Chengdu610039 China State Key Laboratory of Quantum Optics and Quantum Optics Devices Laser Spectroscopy Laboratory College of Physics and Electronics Engineering Shanxi University Taiyuan030006 China Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Collaborative Innovation Center of Advanced Nuclear Energy Technology Institute of Nuclear and New Energy Technology Tsinghua University Beijing100084 China

The variational improved Hulburt-Hirschfelder (VIHH) potential energy model was used to simulate the potential energy curves of BeH+ and CH+ in their ground electronic states. Subsequently, by numerically solving the radial Schrödinger equation using the VIHH potential energy function with the LEVEL program, the rovibrational energy levels of the ground electronic states of BeH+ and CH+ were obtained, determining the molar entropy, enthalpy, and reduced molar Gibbs free energy in the temperature range of 100-6000K within the framework of the overall theory of quantum statistics. © 2024, The Authors. All rights reserved.

关键词： Free energy

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