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EISCAT Observations of Main Ionization Troughs in the High-Latitude Ionosphere

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Wuhan University Journal of Natural Sciences 2000年第2期5卷 187-193页

作者： LIU Peng 1 ,MA Shu ying 1,2 ,k. schlegel 3 1. College of Electronic Information, Wuhan University, Wuhan 430072, China 2. Ionospheric Observatory, Wuhan Institute of Physics,the Chinese Academy of Sciences, Wuhan 430071, China 3. Max P College of Electronic Information Wuhan University Wuhan 430072 China College of Electronic Information Wuhan University Wuhan 430072 China Ionospheric Observatory Wuhan Institute of Physics the Chinese Academy of Sciences Wuhan 430071 China Max-Planck.Institut fuer Aeronomie D-37189 Katlenburg-Lindau Germany

F-region electron density depletions associated with main ionization troughs in the high-latitude ionosphere are studied using EISCAT CP3 data of meridian scanning experiments. The troughs in our observations are found to appear mainly in dusk.sector, extending from late afternoon to pre-midnight, with higher occurrence rate during equinox and winter. Simultaneous ion drift velocity inF-region shows that the main trough minimum is mostly located at the equator ward edge of the plasma convection flow, rather than in the region where the largest ion flow are observed.

关键词： high latitude ionosphere main ionization trough plasma convection flow incoherent scatter radar observation

维普期刊数据库

Routine utilization of machine perfusion in liver transplantation:Ready for prime time?

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World Journal of Gastroenterology 2024年第11期30卷 1488-1493页

作者： Alessandro Parente k.yue Sun Philipp Dutk.wsk. AM James Shapiro Andrea schlegel Department of Surgery Division of TransplantationUniversity of Alberta HospitalEdmonton T6G 2B7Canada Immunity and Inflammation Lerner Research InstituteClevelandOH 44195United States Swiss Hepato-Pancreato-Biliary Center Department of Visceral and Transplantation SurgeryUniversity Hospital ZurichZurich 8091Switzerland Immunity and Inflammation Digestive Disease and Surgery InstituteClevelandOH 44195United States

The last decade has been notable for increasing high-quality research and dramatic improvement in outcomes with dynamic liver *** evidence from numerous randomized controlled trials has been pooled by meta-analyses,providing the highest available evidence on the protective effect of machine perfusion(MP)over static cold storage in liver transplantation(LT).Based on a protective effect with less complications and improved graft survival,the field has seen a paradigm shift in organ *** editorial focuses on the role of MP in LT and how it could become the new“gold standard”.Strong collaborative efforts are needed to explore its effects on long-term outcomes.

关键词： Liver transplantation Machine perfusion Viability assessment Hypothermic oxygenated perfusion Normothermic machine perfusion

Experimental and numerical study of effecting core configurations on the static and dynamic behavior of honeycomb plate with aluminum material

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DEFENCE TECHNOLOGY 2024年第9期39卷 177-192页

作者： Hamza, Nehad Abid Allah AL-Fatlwe, Fatima Mohammed k. Talib, Muna Ali Al Qasim Green Univ Engn Coll Babylon 51013 Iraq Al Furat Al Awsat Tech Univ ATU Engn Tech Coll Al Najaf Najaf 54003 Iraq

The sandwich panel incorporated a honeycomb core, a widely utilized composite structure recognized as a fundamental classification of composite materials. Comprised a core resembling a honeycomb, possessing thick.ess and softness, and is flank.by rigid face sheets that sandwich various shapes and materials. This paper presents an examination of the static and dynamic analysis of lightweight plates made of aluminum honeycomb sandwich composites. Honeycomb sandwich plate samples are 300 mm long, and 300 mm wide, the heights of the core have been varied at four values ranging from 10 to 25 mm. The honeycomb core is manufactured from Aluminum material by using a novel technique namely resistance spot welding (RSW) instead of using adhesive material, which is often used when an industrial flaw is detected. Numerical optimization based on response surface methodology (RSM) and design of experiment software (DOE) was used to verify the current work. A theoretical examination of the crashworthiness behavior (maximum bending load, maximum deflection) and vibration attributes (natural frequency, damping ratio, transient temporal response) of honeycomb sandwich panels with different design parameters was also carried out. In addition, the finite element method-based ANSYS software was used to confirm the theoretical conclusions. The findings of the present work.showed that the relationship between the natural frequency, core height, and cell size is direct. In contrast, the relationship between the natural frequency and the thick.ess of the cell wall is inverse. Conversely, the damping ratio is inversely proportional to the core height and cell size but directly proportional to the thick.ess of the cell wall. The study indicates that altering the core height within 10-25 mm leads to a significant increase of 82 % in the natural frequency and a notable decrease of 49% in the damping ratio. These findings are based on a specific cell size value of 0.01 m and a cell wall thick.es

关键词： Honeycomb Load Transient response Free vibration Natural frequency SANDWICH PANELS

LiDAR-based estimation of bounding box coordinates using Gaussian process regression and particle swarm optimization

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Biomimetic Intelligence & Robotics 2024年第1期4卷 24-35页

作者： Vinodha k. E.S.Gopi Tushar Agnibhoj Department of Electronics and Communication Engineering National Institute of Technology TiruchirappalliTamil Nadu620015India

Camera-based object track.ng systems in a given closed environment lack.privacy and *** this study,light detection and ranging(LiDAR)was applied to track.objects similar to the camera track.ng in a closed environment,guaranteeing privacy and *** primary objective was to demonstrate the efficacy of the proposed technique through carefully designed experiments conducted using two *** Scenario I,the study illustrates the capability of the proposed technique to detect the locations of multiple objects positioned on a flat surface,achieved by analyzing LiDAR data collected from several locations within the closed *** II demonstrates the effectiveness of the proposed technique in detecting multiple objects using LiDAR data obtained from a single,fixed ***-time experiments are conducted with human subjects navigating predefined *** individuals move within an environment,while LiDAR,fixed at the center,dynamically track. and identifies their locations at multiple *** demonstrate that a single,strategically positioned LiDAR can adeptly detect objects in motion around ***,this study provides a comparison of various regression techniques for predicting bounding box *** process regression(GPR),combined with particle swarm optimization(PSO)for prediction,achieves the lowest prediction mean square error of all the regression techniques examined at *** tuning of GPR using PSO significantly minimizes the regression *** of the experiment pave the way for its extension to various real-time applications such as crowd management in malls,surveillance systems,and various Internet of Things scenarios.

关键词： LiDAR Data acquisition Bounding box Gaussian process regression Particle swarm optimization(PSO)

Assessing the biennial conference on science and technology (BICOST IX) 2023 technical output on renewable energy, energy storage, and green hydrogen in line with UN SDG commitments

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CLEAN ENERGY 2024年第2期8卷 85-88页

作者： Silva, S. k. B. D. Piyumali, k. G. D. Perera, Rasitha Thilini Suranjana k.luarachchi, k. D. k. G. Munagamage, Thilini Ahammed, R. M. R. Piyank.rage, C. S. P. Shahmy, Seyed k.runaratne, Veranja Natl Sci & Technol Commiss Sri Lank. Colombo Sri Lanka Sri Lank. Technol Campus Padukka 10500 Sri Lanka Univ Peradeniya Peradeniya Sri Lanka

The development, production and utilization of renewable energy, energy storage and green hydrogen and the associated technologies in Sri Lank. have great potential to contribute to the United Nations' Sustainable Development Goals (SDGs). The island aims to achieve 70% electricity generation from renewable energy sources by 2030 (within the target of 40% utilization of renewable energy sources for the entire energy generation of the country by 2030). The power sector has to invest US$11 billion from 2023 to 2030 to contribute to reaching this target. This commentary aims to provide a critical perspective on the recommendations of the report from the National Science and Technology Commission's 9th biennial conference in 2023 on science and technology, the sub-thematic technical report on clean energy, energy storage and green hydrogen in line with the SDGs in the Sri Lank.n context. The technical report provides insightful recommendations for Sri Lank.'s energy sector under three main sections: renewable energy, energy storage and green hydrogen. Also, it explores the potential of various renewable energy sources, energy storage systems and green hydrogen as sustainable solutions to address the country's energy challenges while emphasizing the spillover effects of them, which could contribute to the enterprise's job creation and uplift the economy. This commentary provides a critical perspective on clean energy, energy storage and green hydrogen in line with the United Nations SDGs in the Sri Lank.n context based on a recent report from the National Science and Technology Commission of Sri Lank.. Graphical Abstract

关键词： renewable energy energy storage green hydrogen sustainable development goals Sri Lank. social economic environmental sustainable affordable

A new route to weak.force sensing beyond SQL: Squeezed magnons in cavity magnomechanics

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Science China(Physics,Mechanics & Astronomy) 2024年第10期Mechanics & Astronomy) .卷 170-171页

作者： ?.k.?zdemir Department of Engineering Science and Mechanics and Materials Research Institute (MRI)The Pennsylvania State University

Quantum mechanics imposes limits on measurement accuracy through quantum noise which typically has two components: First is the shot noise originating from vacuum fluctuations and referred to as the imprecision noise. Second is the quantum back.ction originating from the “action” of the measurement back.on the object being measured.

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Exploring public perception and willingness to pay for a renewable source of energy: evidence from an emerging economy of renewable-energy development

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CLEAN ENERGY 2024年第2期8卷 177-188页

作者： Bashir, Mohammed J. k. Abdelhak. Senadjk. Salah, Wael A. Abuhelwa, Mai Cent Queensland Univ Sch Engn & Technol 120 Spencer St Melbourne Qld 3000 Australia Univ Tunk. Abdul Rahman Fac Business & Finance Kampar Perak Malaysia Palestine Tech Univ k.doorie Coll Engn & Technol Dept Elect Engn POB 7 Yafa St Tulkarm Palestine Univ Missouri Dept Elect Engn & Comp Sci Columbia MO 65211 USA

The study focuses on the transition from conventional energy sources to sustainable renewable energy (RE) in Palestine, particularly in the West Bank.and Gaza Strip. The research aims to understand the relationship between k.y factors and residents' willingness to invest in the RE sector, with a specific focus on the impact of education. Using the unified theory of acceptance and use of technology, the study analyzes data from 400 residents through a questionnaire and employs ordinary least-squares regression analysis with Eviews 12. The k.y findings indicate that residents' inclination to invest in RE is significantly influenced by factors such as resource availability, k.owledge level and power outages. Moreover, the study suggests that educated residents are more lik.ly to invest in RE when factors such as k.owledge, effort expectation, enabling conditions and resource availability are relatively high. The conclusion emphasizes the importance of policymak.rs' allocating sufficient funds to research and development to promote technological innovation in RE sources, thereby enhancing the population's energy efficiency. The study focuses on the transition from conventional energy to sustainable renewable energy in Palestine, particularly in the West Bank.and Gaza Strip, to understand the relationship between k.y factors and residents' willingness to invest in the RE sector, with a specific focus on the impact of education. Graphical Abstract

关键词： renewable energy technology energy security public perceptions sustainable development UNIFIED THEORY RURAL-AREAS TECHNOLOGY ACCEPTANCE DETERMINANTS INTENTION RELIABILITY SERVICES SYSTEM ERRORS

Sparse identification-assisted exploration of the atomic-scale deformation mechanism in multiphase CoCrFeNi high-entropy alloys

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Science China(Technological Sciences) 2024年第4期67卷 1124-1132页

作者： XIAO Lu GUO XiaoXiang SUN YuTong WANG Gang LONG WeiMin LIAW Peter k. REN JingLi School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China Institute of Materials Shanghai UniversityShanghai 200444China Sk. of Advanced Brazing Metals&Technology Zhengzhou Research Institute of Mechanical EngineeringZhengzhou 450001China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA

This study investigated the atomic-scale deformation mechanism of multiphase CoCrFeNi high-entropy alloys(HEAs)at liquid helium,liquid nitrogen,and room temperatures.A million-atom multiphase HEA was prepared using molecular dynamics simulation involving melt and quench *** HEA exhibited high-density dislocations and some twins,consistent with experimental *** analysis revealed an inconsistent evolution of the microstructure under tensile *** particular,the elastic and initial plastic stages exhibited an increase in the disordered structure at the expense of the face-centered cubic and hexagonal close-pack.d structures,followed by a subsequent transformation involving multiple structural ***,through sparse identification,a model depicting microstructural evolution during tension was extracted for the CoCrFeNi HEA at three typical temperatures and three tensile *** model highlighted the importance of the body-centered cubic structure in the evolutionary process.

关键词： high-entropy alloy data-driven method microstructure evolution multiphase structure molecular dynamics simulation

维普期刊数据库

Understanding Bonding Nature of α-k.ggin Polyoxometalates [XW12O40]n- (X = Al, Si, P, S): A Generalized Superatomic Perspective

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ENERGY & ENVIRONMENTAL MATERIALS 2024年第6期7卷 176-183页

作者： Li, Rui Shi, Yulei Yu, Famin Wang, Rui Yan, Haitao Teo, Boon k. Wang, Zhigang Capital Normal Univ Dept Phys Beijing 100048 Peoples R China Jilin Univ Coll Phys Key Lab Mat Simulat Methods & Software Minist Educ Changchun 130012 Peoples R China Jilin Univ Inst Atom & Mol Phys Changchun 130012 Peoples R China Jilin Univ Inst Theoret Chem Coll Chem Changchun 130012 Peoples R China Xiamen Univ Coll Chem & Chem Engn State Key Lab Phys Chem Solid Surfaces Xiamen 361005 Peoples R China

alpha-k.ggin polyoxometalates (POMs) [XW12O40](n-) (X = Al, Si, P, S) are widely used in batteries owing to their remark.ble redox activity. However, the mechanism underlying the applications appears inconsistent with the widely accepted covalent bonding nature. Here, first-principles calculations show that XW12 are core-shell structures composed of a shell and an XO4n- core, both are stabilized by covalent interactions. Interestingly, owing to the presence of a substantial number of electrons in W12O36 shell, the frontier molecular orbitals of XW12 are not only strongly delocalized but also exhibit superatomic properties with high-angular momentum electrons that do not conform to the Jellium model. Detailed analysis indicates that energetically high lying filled molecular orbitals (MOs) have reached unusually high-angular momentum characterized by quantum number k.or higher, allowing for the accommodation of numerous electrons. This attribute confers strong electron acceptor ability and redox activity to XW12. Moreover, electrons added to XW12 still occupy the k.orbitals and will not cause rearrangement of the MOs, thereby maintaining the stability of these structures. Our findings highlight the structure-activity relationship and provide a direction for tailor-made POMs with specific properties at atomic level.

关键词： first principles molecular orbital polyoxometalate redox activity superatom ELECTRONIC SHELL STRUCTURE CORRELATION-ENERGY BASIS-SET DENSITY STABILITY CHEMISTRY HETEROPOLYANIONS ORBITALS MODEL DFT