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Influence of self-similar stresses on scenario earthquake construction:An example along the Tanlu Fault

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Science China Earth Sciences 2024年第5期67卷 1687-1697页

作者： Feng hu huajian YAO Houyun YU zeyu LU Jieyi HOU Song LUO Zhigang SHAO Xiaofei CHEN School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Mengcheng Geophysical National Field Scientific Observatory Hefei 230026China Department of Earth and Space Science Southern University of Science and TechnologyShenzhen 518055China Institute of Earthquake Prediction China Earthquake AdministrationBeijing 100036China

As a famous deep and large fault in eastern China,the Tanlu Fault passes through Anhui,Jiangsu,and Shandong and into northeastern China.It is important to improve the understanding of seismic hazard assessments in areas near faults.We start a scenario earthquake simulation in the M7.5 earthquake potential area of the Xinyi-Sihong segment of the Tanlu Fault.The fault rupture length and width are constrained according to the scaling law of large intraplate earthquakes,the background normal stress is depth dependent,and the initial shear stresses are determined using trial and error by matching the earthquake magnitude.Considering the 120 km rupture length of the M7.5 earthquake,we compare the horizontal uniform stress model and self-similar stress perturbation model.Our findings reveal that the seismic source time function of the horizontal uniform stress model is similar to that of the Haskell model and that of the self-similar stress perturbation model is more similar to that of a real earthquake case.We compare the dynamic rupture simulation and ground motion results under four different stress conditions and find that the shorter the characteristic length of the self-similar function is,the rougher the initial stress.For the M7.5earthquake with an epicenter in the vicinity of Suqian,the Xinyi-Tancheng segment,which is located in the IX-intensity zone north of the epicenter,vibrates more strongly on the northern side than on the southern side due to the influence of the lowvelocity zone and the peak slip rate.The response spectra analysis at stations in the study area is useful for improving the earthquake resistance capability.

关键词： Scenario earthquakes Self-similar stress Tanlu Fault Dynamic rupture Ground motion

Grouping-Based Optimal Design of Collector System Topology for a Large-Scale Offshore Wind Farm by Improved Simulated Annealing

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Protection and Control of Modern Power Systems 2024年第1期9卷 94-111页

作者： Ruilin Chen zeyu Zhang Junxuan hu Lei Zhao Chuangzhi Li Xiaoshun Zhang Shantou University ShantouChina ZHONGNAN ENGINEERING CORPORATION LIMITED North China Electric Power University Department of Electronic and Information Engineering College of EngineeringShantouUniversityShantouChina Sichuan university ChengduChina Foshan Graduate School Northeastern UniversityFoshan 528311China College of Information Science and Engineering Northeastern UniversityShenyang 110819China

During the construction of an offshore wind farm(OWF),the capital cost of the collector cable system accounts for a large proportion of the total cost.Consequently,the optimal design of the collector system topology(CST)is one of the most crucial tasks in OWF planning.However,for a large-scale OWF,the optimal design of CST is a complex integer programming problem with high-dimension variables and various constraints.Therefore,it is difficult to acquire a high-quality optimal design scheme.To address this issue,this paper proposes a new grouping-based optimal design of CST for a large-scale OWF.First,all the wind turbines are divided into multiple groups according to their geographical locations and the maximum allowed connected wind turbines by each cable.This not only reduces the optimization dimension and difficulty,but also effectively satisfies the‘no cross’constraint by putting the geographically closed wind turbines into the same group.Secondly,the electrical topology among different wind turbines in each group is initially generated by an improved dynamic minimum spanning tree(DMST).The division groups of the OWF are then adjusted to further reduce the capital cost by improved simulated annealing.To verify the proposed technique,comparison case studies are carried out with five algorithms on two different OWF.

关键词： dimension Optimal initially

An axisymmetric characteristic model for enhancing prediction of centrifugal compressor characteristics

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Chinese Journal of Aeronautics 2024年第4期37卷 203-215页

作者： Peng REN Xiangjun FANG zeyu JIAO Ying HAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Guangdong Key Laboratory of Modern Control Technology Institute of Intelligent ManufacturingGuangdong Academy of SciencesGuangzhou 510070China

Rapid and accurate determination of compressor characteristic maps is essential for the initial design of centrifugal compressors in aircraft power systems. The accuracy of existing methodologies, which rely on combinations of loss models, varies significantly depending on the compressor's geometry and operational range. This variance necessitates substantial experimental or Computational Fluid Dynamics(CFD) data for coefficient calibration. To address this challenge, this study presents an axisymmetric characteristic model for compressor performance assessment. This model incorporates the factors of blade angle, meridional passage area, and the radial deflection angle of meridional streamlines of the compressor. These factors are derived from fundamental aerodynamic equations encompassing mass, momentum, and energy conservation of the compressor. In contrast to conventional one-dimensional approaches, the proposed method reduces the number of loss coefficients and more effectively accounts for the impact of geometric alterations on centrifugal compressor properties. Furthermore, the model reduces dependence on experimental and CFD data. Efficacy of the model is validated using experimental data from four distinct types of centrifugal compressors. Correlation analysis reveals that the model's coefficients can be expressed as functions of the ratio of the Reynolds number to the impeller tip speed. This ratio serves as a characteristic parameter for the design and optimization of centrifugal compressors. Consequently, the proposed method offers an efficient and accurate means for the quick computation of centrifugal compressor characteristics. This is of great significance for improving the efficiency of centrifugal compressors and reducing energy consumption.

关键词： Centrifugal compressor Positive problem Characteristic prediction Aerodynamic characteristic Axisymmetric model

Engineering tantalum nitride for efficient photoelectrochemical water splitting

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Science China Chemistry 2024年第7期67卷 2171-2180页

作者： Beibei Zhang zeyu Fan Yanbo Li Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

Photoelectrochemical(PEC)water splitting is a promising energy conversion strategy for directly converting solar energy into green hydrogen fuel.Constructing an efficient PEC device,finding an efficient photoanode material with a suitable band gap and favorable band-edge positions is essential.Tantalum nitride(Ta_(3)N_(5))meets these fundamental requirements,and its theoretical maximum solar-to-hydrogen(STH)conversion efficiency can reach 15.9%.Consequently,it has been widely applied as a photoanode material for the PEC oxygen evolution reaction(OER).However,severe bulk and interface charge recombination,along with sluggish water oxygen kinetics,seriously limits its STH conversion efficiency for PEC water splitting.Herein,this feature article briefly reviews recent advances by our research group in improving the STH conversion efficiency of the Ta_(3)N_(5)photoanode using various strategies,including defect engineering,construction of a gradient band structure,interface engineering,and surface modification of self-healing OER cocatalyst.Up to now,the obtained half-cell STH efficiency has exceeded 4%,providing a solid foundation for the development of tandem PEC devices for unbiased solar-driven overall water splitting toward practical application.

关键词： Photoelectrochemical water splitting tantalum nitride defect engineering interface engineering oxygen evolution cocatalyst

Influence of Current Density on the Photocatalytic Activity of Nd:TiO_(2) Coatings

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 32-38页

作者：施渊吉 ZHANG Zhen DAI Yunzhong LI Jingxiao CHEN zeyu School of Mechanical Engineering Nanjing Vocational University of Industry TechnologyNanjing 210046China College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China Key Laboratory of Modern Agricultural Equipment and Technology Jiangsu UniversityZhenjiang 212013China

The Nd:TiO_(2 )PEO coatings were formed in a phosphate-based electrolyte with the addition of Nd_(2)O_(3 )under the current density of 150,200,250 and 300 m A/cm^(2).SEM results showed that the micropores decreased on quantity and increased on scale with the increasing current density.AFM results revealed that the roughness of the coatings increased with the increasing current density.Phase and composition analysis showed that the Nd:TiO_(2) coatings were mainly composed of anatase and rutile phase.And the anatase phase content has reached the maximum value at the current density of 250 m A/cm^(2).XPS results indicated that Ti2p spin-orbit components of the Nd:TiO_(2) coatings are shifted towards higher binding energy,compared with the pure TiO_(2) coating,suggesting that some of the Nd^(3+)ions are combined with TiO_(2) lattice and led to dislocation.Photocatalytic test showed that the photocatalytic activity of Nd:TiO_(2) coatings varied in the same pattern with the anatase content variation in Nd:TiO_(2) coatings.The photocatalytic experiment results show that the photocatalytic activity of Nd:TiO_(2) coatings can be greatly enhanced with moderate amount of Nd^(3+).However,excessive amount of Nd^(3+)does not have an effective impact on the photoctalytic activity improvement.

关键词： PEO current density AFM XPS Nd:TiO_(2) photocatalytic

Effects of high-dose glucose-insulin-potassium on acute coronary syndrome patients receiving reperfusion therapy:a meta-analysis

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World Journal of Emergency Medicine 2024年第3期15卷 181-189页

作者： zeyu Yang huiruo Liu Dazhou Lu Shengchuan Cao Feng Xu Chuanbao Li Department of Emergency Medicine Qilu Hospital of Shandong UniversityJinan 250012China Shandong Provincial Clinical Research Center for Emergency and Critical Care Medicine Institute of Emergency and Critical Care Medicine of Shandong UniversityChest Pain CenterQilu Hospital of Shandong UniversityJinan 250012China Key Laboratory of Emergency and Critical Care Medicine of Shandong Province Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Research of Shandong ProvinceShandong Provincial Engineering Laboratory for Emergency and Critical Care MedicineQilu Hospital of Shandong UniversityJinan 250012China Shandong Key Laboratory:Magnetic Field-free Medicine&Functional Imaging(MF) Qilu Hospital of Shandong UniversityJinan 250012China National Medical Products Administration(NMPA)Key Laboratory for Clinical Research and Evaluation of Innovative Drug Qilu Hospital of Shandong UniversityJinan 250012China

BACKGROUND:This meta-analysis aimed to assess the efficacy of high-dose glucose-insulinpotassium(GIK) therapy on clinical outcomes in acute coronary syndrome(ACS) patients receiving reperfusion therapy.METHODS:We searched the PubMed,Web of Science,MEDLINE,Embase,and Cochrane Library databases from inception to April 26,2022,for randomized controlled trials(RCTs) that compared high-dose GIK and placebos in ACS patients receiving reperfusion therapy.The primary endpoint was major adverse cardiovascular events(MACEs).RESULTS:Eleven RCTs with 884 patients were ultimately included.Compared with placebos,high-dose GIK markedly reduced MACEs(risk ratio [RR] 0.57,95% confidence interval [95% CI]:0.35 to 0.94,P=0.03) and the risk of heart failure(RR 0.48,95% CI:0.25 to 0.95,P=0.04) and improved the left ventricular ejection fraction(LVEF)(mean difference [MD] 2.12,95% CI:0.40 to 3.92,P=0.02) at 6 months.However,no difference was observed in all-cause mortality at 30 d or 1 year.Additionally,high-dose GIK was significantly associated with increased incidences of phlebitis(RR 4.78,95% CI:1.36 to 16.76,P=0.01),hyperglycemia(RR 9.06,95% CI:1.74 to 47.29,P=0.009) and hypoglycemia(RR 6.50,95% CI:1.28 to 33.01,P=0.02) but not reinfarction,hyperkalemia or secondary reperfusion.In terms of oxidative stress-lowering function,high-dose GIK markedly reduced superoxide dismutase(SOD) activity but not glutathione peroxidase(GSH-Px) or catalase(CAT) activity.CONCLUSION:Patients with ACS receiving reperfusion therapy exhibited a reduction in MACEs and good oxidative stress-lowering eflcacy in response to high-dose GIK.Moreover,with a higher incidence of complications such as phlebitis,hyperglycemia,and hypoglycemia.Furthermore,there were no observed survival benefits associated with high-dose GIK.More trials with long-term follow-up are still needed.

关键词： Acute coronary syndrome High-dose Glucose-insulin-potassium treatment Reperfusion therapy Meta-analysis

Flow characteristics of radial inflow in impeller rear cavity with baffle plate

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Chinese Journal of Aeronautics 2024年第2期37卷 270-282页

作者： Yang BAI Xiang LUO Dongdong LIU zeyu WU Xiaoqiang ZHANG Sipeng WANG Research Institute of Aero-Engine Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China School of Energy and Power Engineering Beihang UniversityBeijing 100191China

The research purpose of this paper is to explore the influence of the baffle plate on the airflow in the rear cavity of the centrifugal impeller and optimize the performance of the secondary air system’s air bleed section.In this paper,a comprehensive experimental study was carried out on the flow characteristics in the impeller rear cavity with baffle plate.The windage torque,flow structure and pressure drop between inlet and outlet were measured respectively.The experiment was carried out with the condition that the range of rotational Reynolds number was from 8.33×10^(5)to 22.2×10^(5)and the range of mass flow rate coefficient was from 0.92×10^(4)to 2.92×10^(4).The results show that the static cavity and the narrow stator-rotor cavity formed by the baffle plate effectively suppress the overall swirl coefficient in the cavity.Thus,the static pressure and total pressure drop in the rotor-stator cavity were reduced.The influence of the baffle plate on the windage torque of the rotary disk is related to the turbulence parameters.Under large turbulence parameters,the windage torque would be reduced with baffle plate,while under small turbulence parameters,the baffle plate would increase with baffle plate.In general,the baffle plate can improve the flow capacity and optimize the bleed air performance with proper structure and operation conditions.

关键词： Impeller rear cavity Baffle plate Flow structure Windage torque Pressure drop

Attitude control of multi-spacecraft systems on SO(3)with stochastic links failure

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Chinese Journal of Aeronautics 2024年第3期37卷 320-331页

作者： KANG zeyu SHEN Qiang WU Shufan Chris J.DAMAREN MU Zhongcheng School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Institute for Aerospace Studies University of TorontoTorontoOntario M3H 5T6Canada

In this paper,for Multi-Spacecraft System(MSS)with a directed communication topology link and a static virtual leader,a controller is proposed to realize attitude consensus and attitude stabilization with stochastic links failure and actuator saturation.First,an MSS attitude error model suitable for a directed topology link and with a static virtual leader based on SO(3)is derived,which considers that the attitude error on SO(3)cannot be defined based on algebraic subtraction.Then,we design a controller to realize the MSS on SO(3)with attitude consensus and attitude stabilization under stochastic links failure and actuator saturation.Finally,the simulation results of a multi-spacecraft system with stochastic links failure and a static virtual leader spacecraft are demonstrated to illustrate the efficiency of the attitude controller.

关键词： Multi-spacecraft systems Attitude consensus Attitude stabilization Stochastic links failure Super-martingale convergence

Collaborative positioning for swarms:A brief survey of vision,LiDAR and wireless sensors based methods

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Defence Technology（防务技术） 2024年第3期33卷 475-493页

作者： zeyu Li Changhui Jiang Xiaobo Gu Ying Xu Feng zhou Jianhui Cui College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdao266590China Geoloc Laboratory Universite Gustave EiffelParis77454France School of Automation Guangdong University of TechnologyGuangzhou510006China

As positioning sensors,edge computation power,and communication technologies continue to develop,a moving agent can now sense its surroundings and communicate with other agents.By receiving spatial information from both its environment and other agents,an agent can use various methods and sensor types to localize itself.With its high flexibility and robustness,collaborative positioning has become a widely used method in both military and civilian applications.This paper introduces the basic fundamental concepts and applications of collaborative positioning,and reviews recent progress in the field based on camera,LiDAR(Light Detection and Ranging),wireless sensor,and their integration.The paper compares the current methods with respect to their sensor type,summarizes their main paradigms,and analyzes their evaluation experiments.Finally,the paper discusses the main challenges and open issues that require further research.

关键词： Collaborative positioning Vision LiDAR Wireless sensors Sensor fusion