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An eikonal equation-based earthquake location method by inversion of multiple phase arrivals

Science China Earth Sciences 2024年第6期67卷 1802-1817页

作者： Gaoyue LAO Dinghui yang Shaolin LIU Guiju DONG Wenshuai WANG kui LIU National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China School of Earth Sciences Yunnan UniversityKunming 650091China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China School of Mathematics and Statistics Ningxia UniversityYinchuan 750021China

The precise determination of earthquake location is the fundamental basis in seismological community,and is crucial for analyzing seismic activity and performing seismic tomography.First arrivals are generally used to practically determine earthquake locations.However,first-arrival traveltimes are not sensitive to focal depths.Moreover,they cannot accurately constrain focal depths.To improve the accuracy,researchers have analyzed the depth phases of earthquake locations.The traveltimes of depth phases are sensitive to focal depths,and the joint inversion of depth phases and direct phases can be implemented to potentially obtain accurate earthquake locations.Generally,researchers can determine earthquake locations in layered models.Because layered models can only represent the first-order feature of subsurface structures,the advantages of joint inversion are not fully explored if layered models are used.To resolve the issue of current joint inversions,we use the traveltimes of three seismic phases to determine earthquake locations in heterogeneous models.The three seismic phases used in this study are the first P-,sPg-and PmP-waves.We calculate the traveltimes of the three seismic phases by solving an eikonal equation with an upwind difference scheme and use the traveltimes to determine earthquake locations.To verify the accuracy of the earthquake location method by the inversion of three seismic phases,we take the 2021 M_(S)6.4 yangbi,Yunnan earthquake as an example and locate this earthquake using synthetic and real seismic data.Numerical tests demonstrate that the eikonal equation-based earthquake location method,which involves the inversion of multiple phase arrivals,can effectively improve earthquake location accuracy.

关键词： Earthquake location Eikonal equation Fast marching method Heterogeneous model

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Secure resource allocation against colluding eavesdropping in a user-centric cell-free massive multiple-input multiple-output system

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 500-512页

作者： Na LI Yuanyuan GAO kui XU Xiaochen XIA Huazhi HU yang LI Yueyue ZHANG College of Communication Engineering Army Engineering University of PLANanjing 210007China

We investigate the resource allocation problem of a cell-free massive multiple-input multiple-output system under the condition of colluding eavesdropping by multiple passive eavesdroppers.To address the problem of limited pilot resources,a scheme is proposed to allocate the pilot with the minimum pollution to users based on access point selection and optimize the pilot transmission power to improve the accuracy of channel estimation.Aiming at the secure transmission problem under a colluding eavesdropping environment by multiple passive eavesdroppers,based on the local partial zero-forcing precoding scheme,a transmission power optimization scheme is formulated to maximize the system’s minimum security spectral efficiency.Simulation results show that the proposed scheme can effectively reduce channel estimation error and improve system security.

关键词： Cell-free Colluding eavesdropping Limited pilot resources Access point selection Security rate

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Multi-Objective Optimization of Aluminum Alloy Electric Bus Frame Connectors for Enhanced Durability

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 735-755页

作者： Wenjun Zhou Mingzhi yang Qian Peng Yong Peng kui Wang Qiang Xiao Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410018China School of Mechanical and Automotive Engineering Xiamen University of TechnologyXiamen361024China

The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame protection.Our study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and safety.This research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body connectors.Our goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector components.Three typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and methods.Firstly,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation patterns.Then,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic strain.Lastly,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint components.Subsequently,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending simulations.Each joint component showcased a remarkable 30%–40%mass reduction while boosting energy absorption.Our design optimization method exhibits high efficiency and costeffectiveness.Leveraging contemporary automation technology,the design optimization platform developed in this study is poised

关键词： Aluminum connectors three-point bending simulation parametric design model multi-objective collaborative optimization

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Design and pricing of maintenance service contract based on Nash non-cooperative game approach

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Journal of Systems Engineering and Electronics 2024年第1期35卷 118-129页

作者： SU Chun HUANG kui School of Mechanical Engineering Southeast UniversityNanjing 211189China

Nowadays manufacturers are facing fierce challenge.Apart from the products,providing customers with multiple maintenance options in the service contract becomes more popular,since it can help to improve customer satisfaction,and ultimately promote sales and maximize profit for the manufacturer.By considering the combinations of corrective maintenance and preventive maintenance,totally three types of maintenance service contracts are designed.Moreover,attractive incentive and penalty mechanisms are adopted in the contracts.On this basis,Nash non-cooperative game is applied to analyze the revenue for both the manufacturer and customers,and so as to optimize the pricing mechanism of maintenance service contract and achieve a win-win situation.Numerical experiments are conducted.The results show that by taking into account the incentive and penalty mechanisms,the revenue can be improved for both the customers and manufacturer.Moreover,with the increase of repair rate and improvement factor in the preventive maintenance,the revenue will increase gradually for both the parties.

关键词： maintenance service contract Nash game incentive and penalty mechanism corrective maintenance preventive maintenance

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Improved nuclear mass formula with an additional term from the Fermi gas model

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Nuclear Science and Techniques 2024年第5期35卷 131-138页

作者： Xiao-Yu Xu Li Deng Ai-Xi Chen Hang yang Amir Jalili Han-kui Wang School of Science Zhejiang Sci-Tech UniversityHangzhou 310018China

Nuclear mass is a fundamental property of nuclear physics and a necessary input in nuclear astrophysics.Owing to the complexity of atomic nuclei and nonperturbative strong interactions,conventional physical models cannot completely describe nuclear binding energies.In this study,the mass formula was improved by considering an additional term from the Fermi gas model.All nuclear masses in the Atomic Mass Evaluation Database were reproduced with a root-mean-square deviation(RMSD)of -1.86 MeV(1.92 MeV).The new mass formula exhibits good performance in the neutron-rich nuclear region.The RMSD decreases to 0.393 MeV when the ratio of the neutron number to the proton number is≥1.6.

关键词： Nuclear mass formula Neutron-rich nuclei Fermi-gas model

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Influence of pore structure on thermal stress distribution inside coal particles during primary fragmentation

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Particuology 2024年第2期85卷 49-61页

作者： Kai Qiao Shan Zhong Siyang Tang Ke yang Hairong Yue kui Ma Lei Song Bin Liang School of Chemical Engineering Sichuan UniversityChengdu610065China Institute of New Energy and Low-carbon Technology Chengdu610207China

Thermal stress is an important reason of coal particle primary fragmentation,during which the role of pore structure is ambiguous.Thermal stress induced fragmentation experiments were conducted with low volatile coal/char particles,and the results show that the fragmentation severity enhances with increasing porosity.Various porous thermal stress models were developed with finite element method,and the influences of the pore shape,size,position and porosity on the thermal stress were discussed.The maximum thermal stress inside particle increases with pore curvature,the pore position affects the thermal stress more significantly at the particle center and surface.The expectation of the maximum tensile thermal stress linearly increases with porosity,making the particles with higher porosity easier to fragment,contrary to the conclusion deduced from the devolatilization theory.The obtained results are valuable for the analysis of different thermal processes concerning the thermal stresses of the solid feedstocks.

关键词： Coal particle Primary fragmentation Thermal stress Pore structure Porosity

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Unveiling the role of hypoxia-inducible factor 2alpha in osteoporosis:Implications for bone health

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World Journal of Stem Cells 2024年第4期16卷 389-409页

作者： Ling-Ling Wang Zhan-Jin Lu Shun-kui Luo Yun Li Zhe yang Hong-Yun Lu Department of Gerontology The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000Guangdong ProvinceChina Department of Endocrinology and Metabolism The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000Guangdong ProvinceChina Guangdong Provincial Key Laboratory of Biomedical Imaging The Fifth Affiliated Hospital of Sun Yat-sen UniversityZhuhai 519000Guangdong ProvinceChina Department of Endocrinology and Metabolism Zhuhai People’s Hospital(Zhuhai Clinical Medical College of Jinan Universitythe First Hospital Affiliated with Medical College of Macao University of Science and Technology)Zhuhai 519000Guangdong ProvinceChina

BACKGROUND Osteoporosis(OP)has become a major public health problem worldwide.Most OP treatments are based on the inhibition of bone resorption,and it is necessary to identify additional treatments aimed at enhancing osteogenesis.In the bone marrow(BM)niche,bone mesenchymal stem cells(BMSCs)are exposed to a hypoxic environment.Recently,a few studies have demonstrated that hypoxiainducible factor 2alpha(HIF-2α)is involved in BMSC osteogenic differentiation,but the molecular mechanism involved has not been determined.AIM To investigate the effect of HIF-2αon the osteogenic and adipogenic differentiation of BMSCs and the hematopoietic function of hematopoietic stem cells(HSCs)in the BM niche on the progression of OP.METHODS Mice with BMSC-specific HIF-2αknockout(Prx1-Cre;Hif-2αfl/fl mice)were used for in vivo experiments.Bone quantification was performed on mice of two genotypes with three interventions:Bilateral ovariectomy,semilethal irradiation,and dexamethasone treatment.Moreover,the hematopoietic function of HSCs in the BM niche was compared between the two mouse genotypes.In vitro,the HIF-2αagonist roxadustat and the HIF-2αinhibitor PT2399 were used to investigate the function of HIF-2αin BMSC osteogenic and adipogenic differentiation.Finally,we investigated the effect of HIF-2αon BMSCs via treatment with the mechanistic target of rapamycin(mTOR)agonist MHY1485 and the mTOR inhibitor rapamycin.RESULTS The quantitative index determined by microcomputed tomography indicated that the femoral bone density of Prx1-Cre;Hif-2αfl/fl mice was lower than that of Hif-2αfl/fl mice under the three intervention conditions.In vitro,Hif-2αfl/fl mouse BMSCs were cultured and treated with the HIF-2αagonist roxadustat,and after 7 d of BMSC adipogenic differentiation,the oil red O staining intensity and mRNA expression levels of adipogenesis-related genes in BMSCs treated with roxadustat were decreased;in addition,after 14 d of osteogenic differentiation,BMSCs treated with roxadustat exhibited increased expression of osteogenesis

关键词： Hypoxia-inducible factor-2α Bone marrow niche Bone mesenchymal stem cells Osteoporosis Osteogenic/adipogenic differentiation Mechanistic target of rapamycin signaling pathway

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miR-378a-3p responds to physical activity by modulating insulin-mediated glucose uptake and tricarboxylic acid cycle in skeletal muscle

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Genes & Diseases 2024年第3期11卷 98-101页

作者： Zishuai Wang Yilong Yao Xinhua Hou Danyang Fan Yanwen Liu Adeyinka Abiola Adetula Yalan yang kui Li Zhonglin Tang Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenGuangdong518000China Kunpeng Institute of Modern Agriculiture at Foshan Chinese Academy of Agricultural SciencesFoshanGuangdong528226China GuangXi Engineering Centre for Resource Development of Bama Xiang Pig BamaGuangxi 547500China Institute of Animal Science Chinese Academy of Agricultural SciencesBeijing100193China

Aerobic exercise training alters gene expression in skeletal muscle,and miRNAs significantly contribute to motion response.However,the molecular mechanisms by which miRNAs regulate the response to exercise training are not well understood.Here,we found that the abundance of miR-378a-3p in skeletal muscle significantly decreased after exercise training.miR-378a-3p knockout mice showed increased insulin sensitivity,insulin-mediated glucose uptake.

关键词： skeletal miR uptake

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Examining the association between delay discounting,delay aversion and physical activity in Chinese adults with type-2 diabetes mellitus

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World Journal of Diabetes 2024年第4期15卷 675-685页

作者： Yong-Dong An Guo-Xia Ma Xing-kui Cai Ying yang Fang Wang Zhan-Lin Zhang Department of Endocrinology People's Hospital of Linxia Hui Autonomous PrefectureLinxia Hui Autonomous Prefecture 731100Gansu ProvinceChina Department of Gynecology People's Hospital of Linxia Hui Autonomous PrefectureLinxia Hui Autonomous Prefecture 731100Gansu ProvinceChina The First Clinical Medical College Lanzhou UniversityLanzhou 730013Gansu ProvinceChina Department of Internal Medicine People's Hospital of HezhengLinxia Hui Autonomous Prefecture 731200Gansu ProvinceChina Department of Geratology People's Hospital of Linxia Hui Autonomous PrefectureLinxia Hui Autonomous Prefecture 731100Gansu ProvinceChina Department of Medical People's Hospital of Linxia Hui Autonomous PrefectureLinxia Hui Autonomous Prefecture 731100Gansu ProvinceChina

BACKGROUND The role of physical activity in diabetes is critical,influencing this disease's development,man-agement,and overall outcomes.In China,22.3%of adults do not meet the minimum level of physical activity recommended by the World Health Organization.Therefore,it is imperative to identify the factors that contributing to lack of physical activity must be identified.AIM To investigate the relationship among delay discounting,delay aversion,glycated hemoglobin(HbA1c),and various levels of physical activity in Chinese adults diagnosed with type 2 diabetes mellitus(T2DM).METHODS In 2023,400 adults with T2DM were recruited from the People's Hospital of Linxia Hui Autonomous Prefecture of Gansu Province.A face-to-face questionnaire was used to gather demographic data and details on physical activity,delay discounting,and delay aversion.In addition,HbA1c levels were measured in all 400 participants.The primary independent variables considered were delay discounting and delay aversion.The outcome variables included HbA1c levels and different intensity levels of physical activity,including walking,moderate physical activity,and vigorous physical activity.Multiple linear regression models were utilized to assess the relationship between delay discounting,delay aversion,and HbA1c levels,along with the intensity of different physical activity measured in met-hours per week.RESULTS After controlling for the sample characteristics,delay discounting was negatively associated with moderate physical activity(β=-2.386,95%CI:-4.370 to-0.401).Meanwhile,delay aversion was negatively associated with the level of moderate physical activity(β=-3.527,95%CI:-5.578 to-1.476)in the multiple linear regression model,with statistically significant differences.CONCLUSION Elevated delay discounting and increased delay aversion correlated with reduced levels of moderate physical activity.Result suggests that delay discounting and aversion may influence engagement in moderate physical activity.This study recommends that health administration

关键词： Type 2 diabetes mellitus Delay discounting Delay aversion Physical activity

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A mix & act liposomes of phospholipase A2-phosphatidylserine for acute brain detoxification by blood‒brain barrier selective-opening

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Acta Pharmaceutica Sinica B 2024年第4期14卷 1827-1844页

作者： Zinan Zhang Wenbin Cao Huanchun Xing Shuai Guo Lijuan Huang Lin Wang Xin Sui kui Lu Yuan Luo Yongan Wang Jun yang State Key Laboratory of Toxicology and Medical Countermeasures Beijing Institutes of Pharmacology and ToxicologyBeijing 100850China Tianjin University of Science and Technology Tianjin 300222China Hebei University of Science and Technology Shijiazhuang 050018China

In the treatment of central nervous system disease,the blood-brain barrier(BBB)is a major obstruction to drug delivery that must be overcome.In this study,we propose a brain-targeted delivery strat-egy based on selective opening of the BBB.This strategy allows some simple bare nanoparticles to enter the brain when mixed with special opening material;however,the BBB still maintains the ability to completely block molecules from passing through.Based on the screening of BBB opening and matrix delivery mate-rials,we determined that phospholipase A2-catalyzed 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine li-posomes can efficiently carry drugs into the brain immediately.At an effective dose,this delivery system is safe,especially with its effect on the BBB being reversible.This mix&act delivery system has a simple structure and rapid preparation,making it a strong potential candidate for drug delivery across the BBB.

关键词： Liposomes Phospholipase A2 Phosphoserine Blood-brainbarrier Selectively open Mix&act

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