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Explosion damage effects of aviation kerosene storage tank under strong ignition

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Defence Technology（防务技术） 2024年第7期37卷 27-38页

作者： Shixiang song Cheng Wang Boyang Qiao Gongtian Gu State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

In order to study the blast damage effects of aviation kerosene storage tanks,the out-field explosion experiments of 8 m3fixed-roof tanks were carried *** fragments,shock wave and fireball thermal radiation of the tank in the presence of bottom oil,half oil and full oil,as well as empty tank,were investigated under internal explosion by various TNT charge contents(1.8 kg,3.5 kg and 6.2 kg).The results showed that the tank roof was the only fragment produced,and the damage forms could be divided into three *** increase of TNT charge content and oil volume enlarged the deformation of the tank,while the hole ratio presented a trend of increase first and then *** H_r,maxand V_(max)values positively increased as increasing the TNT charge content and oil volume(from empty to half oil),but decreased in full *** Pmaxvalues had a progressive increase with the increment of TNT charge content,but not the case with the increase in oil *** development of fireball was divided into three stages:tank roof‘towed'flame,jet flow flame tumbling and rising,and jet flow flame *** Dmaxand Hf,maxvalues both increased as increasing TNT charge content and oil *** oscillation phenomenon of fireball temperature was observed in the cooling *** average temperature of fireball surface was positively correlated with TNT charge content,and negatively correlated with oil volumes.

关键词： Aviation kerosene Storage tank Internal explosion Shock wave Fireball

Dynamic analysis and bifurcation control of a delayed fractional-order eco-epidemiological migratory bird model with fear effect

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International Journal of Biomathematics 2024年第3期17卷 1-33页

作者： Caihong song Ning Li College of Sciences Northeastern University 110819 ShenyangLiaoningP.R.China

In this paper,a new delayed fractional-order model including susceptible migratory birds,infected migratory birds and predators is proposed to discuss the spread of diseases among migratory *** of predators is considered in the model,as fear can reduce the reproduction rate and disease transmission rate among ***,some basic mathematical results of the proposed model are ***,time delay is regarded as a bifurcation parameter,and the delay-induced bifurcation conditions for such an uncontrolled system are established.A novel periodic pulse feedback controller is proposed to suppress the bifurcation *** is found that the control scheme can successfully suppress the bifurcation behavior of the system,and the pulse width can be arbitrarily selected on the premise of ensuring the control *** with the traditional time-delay feedback controller,the control scheme proposed in this paper has more advantages in practical application,which not only embodies the advantages of low control cost and easy operation but also caters to the periodic changes of the *** proposed control scheme,in particular,remains effective even after the system has been disrupted by a *** simulation verifies the correctness of the theoretical results.

关键词： Delayed fractional-order migratory birds fear Hopf bifurcation periodic pulse feedback

Mn-doped LiFePO_(4)@C as a high-performance cathode material for lithium-ion batteries

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Particuology 2024年第7期90卷 418-428页

作者： Wenjing Chen Fangxiang song Yumei Yang Qianlin Chen School of Chemistry and Chemical Engineering Guizhou UniversityGuiyang550025China Collaborative Innovation Center of Guizhou Province for Efficient Utilization of Phosphorus and Fluorine Resources Guizhou UniversityGuiyang550025China

In this work,LiFe_(1-x)MnxPO_(4)@C(x=0,0.01,0.02,0.03)cathode materials were obtained by a simple co-precipitation method and heat treatment,and the influence of Mn-doped modification on the electrochemical performance of LiFePO_(4)@C cathode materials was *** show that by doping an appropriate amount of Mn,the cell volume became larger,and the electronic conductivity increased,which improved the Li+diffusion rate and thus its rate capability and cycle performance of Li-ion *** them,LiFe_(0.98)Mn_(0.02)PO_(4)@C showed superior lithium storage capability;the discharge capacity can reach 150.7 mAh g^(−1)at 0.1 *** cell could discharge up to 155.9 mAh g^(−1)at 1 C under high temperature at 45°C,which was higher than LiFePO_(4)@C(142 mAh g^(−1))under the same test *** discharge capacity of 1 C at room temperature was 139.9 mAh g^(−1),and the cycle stability was 95.9%after 200 *** showed that it had good rate capability and excellent cycle *** results indicate that Mn-doped LFP is a simple and effective strategy for developing high-performance cathode materials.

关键词： Mn-doped LiFePO_(4) Lithium-ion battery High temperature

A Data Intrusion Tolerance Model Based on an Improved Evolutionary Game Theory for the Energy Internet

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Computers, Materials & Continua 2024年第6期79卷 3679-3697页

作者： song Deng Yiming Yuan Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing210003China College of Automation Nanjing University of Posts and TelecommunicationsNanjing210003China

Malicious attacks against data are unavoidable in the interconnected,open and shared Energy Internet(EI),Intrusion tolerant techniques are critical to the data security of *** intrusion tolerant techniques suffered from problems such as low adaptability,policy lag,and difficulty in determining the degree of *** address these issues,we propose a novel adaptive intrusion tolerance model based on game theory that enjoys two-fold ideas:(1)it constructs an improved replica of the intrusion tolerance model of the dynamic equation evolution game to induce incentive weights;and (2)it combines a tournament competition model with incentive weights to obtain optimal strategies for each stage of the game *** experiments are conducted in the IEEE 39-bus system,whose results demonstrate the feasibility of the incentive weights,confirm the proposed strategy strengthens the system’s ability to tolerate aggression,and improves the dynamic adaptability and response efficiency of the aggression-tolerant system in the case of limited resources.

关键词： Energy Internet Intrusion tolerance game theory racial competition adaptive intrusion response

Experimental and Numerical Investigation on the Aerodynamic Characteristics of High-Speed Pantographs with Supporting Beam Wind Deflectors

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Fluid Dynamics & Materials Processing 2024年第1期20卷 127-145页

作者： Shiyang song Tongxin Han Postgraduate Department China Academy of Railway SciencesBeijing100081China Locomotive&Car Research Institute China Academy of Railway Sciences Corporation LimitedBeijing100081China

Aiming to mitigate the aerodynamic lift force imbalance between pantograph strips,which exacerbates wear and affects the current collection performance of the pantograph-catenary system,a study has been conducted to support the beam deflector optimization using a combination of experimental measurements and computational fluid dynamics(CFD)*** results demonstrate that the size,position,and installation orientation of the wind deflectors significantly influence the amount of force *** also indicate that the front strip deflectors should be installed downwards and the rear strip deflectors upwards,thereby forming a“π”***,the lift force compensation provided by the wind deflectors increases with the size of the *** wind compensation strategies,such as control circuits,are also discussed,putting emphasis on the pros and cons of various pantograph types and wind compensation approaches.

关键词： High-speed pantograph aerodynamic lift force supporting beam wind deflectors computational fluid dynamics(CFD)

Random Forest-Based Fatigue Reliability-Based Design Optimization for Aeroengine Structures

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 665-684页

作者： Xue-Qin Li Lu-Kai song School of Energy and Power Engineering Beihang UniversityBeijing100191China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityKowloonHong Kong999077China Research Institute of Aero-Engine Beihang UniversityBeijing100191China

Fatigue reliability-based design optimization of aeroengine structures involves multiple repeated calculations of reliability degree and large-scale calls of implicit high-nonlinearity limit state function,leading to the traditional direct Monte Claro and surrogate methods prone to unacceptable computing efficiency and *** this case,by fusing the random subspace strategy and weight allocation technology into bagging ensemble theory,a random forest(RF)model is presented to enhance the computing efficiency of reliability degree;moreover,by embedding the RF model into multilevel optimization model,an efficient RF-assisted fatigue reliability-based design optimization framework is *** the low-cycle fatigue reliability-based design optimization of aeroengine turbine disc as a case,the effectiveness of the presented framework is *** reliabilitybased design optimization results exhibit that the proposed framework holds high computing accuracy and computing *** current efforts shed a light on the theory/method development of reliability-based design optimization of complex engineering structures.

关键词： Random forest reliability-based design optimization ensemble learning machine learning

Mobile Crowdsourcing Task Allocation Based on Dynamic Self-Attention GANs

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Computers, Materials & Continua 2024年第4期79卷 607-622页

作者： Kai Wei song Yu Qingxian Pan School of Computer and Control Engineering Yantai UniversityYantai264005China School of Computer and Information Science Southwest UniversityChongqing400715China

Crowdsourcing technology is widely recognized for its effectiveness in task scheduling and resource *** traditional methods for task allocation can help reduce costs and improve efficiency,they may encounter challenges when dealing with abnormal data flow nodes,leading to decreased allocation accuracy and *** address these issues,this study proposes a novel two-part invalid detection task allocation *** the first step,an anomaly detection model is developed using a dynamic self-attentive GAN to identify anomalous *** to the baseline method,the model achieves an approximately 4%increase in the F1 value on the public *** the second step of the framework,task allocation modeling is performed using a twopart graph matching *** phase introduces a P-queue KM algorithm that implements a more efficient optimization *** allocation efficiency is improved by approximately 23.83%compared to the baseline *** results confirm the effectiveness of the proposed framework in detecting abnormal data nodes,enhancing allocation precision,and achieving efficient allocation.

关键词： Mobile crowdsourcing task allocation anomaly detection GAN attention mechanisms

风火打捆直流外送系统的直流系统无功补偿装置协调控制策略及配置方案

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电网技术 2016年第7期40卷 2081-2086页

作者：赵云灏夏懿周勤勇宋汶秦孙玉娇刘崇茹李庚银新能源电力系统国家重点实验室(华北电力大学) 北京市昌平区102206 甘肃省电力公司经济技术研究院甘肃省兰州市730030 中国电力科学研究院北京市海淀区100192

在风火打捆经直流外送系统中,风电功率波动将加重送端系统调峰调频压力,当直流系统采用变功率定电压输电控制策略时,可将送端调峰调频压力通过直流系统转移到网架结构较强、有充分调峰调频能力的受端地区,但同时将增加电容器等常规无功... 详细信息

在风火打捆经直流外送系统中,风电功率波动将加重送端系统调峰调频压力,当直流系统采用变功率定电压输电控制策略时,可将送端调峰调频压力通过直流系统转移到网架结构较强、有充分调峰调频能力的受端地区,但同时将增加电容器等常规无功补偿装置的投切次数。为减少直流跟随风电波动时常规无功补偿装置的投切次数,提出了使用SVC替代常规无功补偿装置的方案,并提出相应的SVC和常规无功补偿装置的协调控制策略以及无功补偿装置容量优化配置方案。PSCAD/EMTDC仿真表明,所提SVC和常规无功补偿装置的协调控制策略可在不改变直流输电系统常规无功补偿装置基本控制策略的前提下,有效减少此过程中常规无功补偿装置的投切次数。同时容量优化配置结果表明,所提无功补偿装置容量优化配置方案可在满足换流母线电压约束和常规无功补偿装置投切次数约束的前提下,对SVC和常规无功补偿装置容量进行合理的优化配置,使SVC和常规无功补偿装置的总投资最小。

关键词：风火打捆直流系统无功补偿装置控制策略容量优化

Approximately Bi-Similar Symbolic Model for Discretetime Interconnected Switched System

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IEEE/CAA Journal of Automatica Sinica 2024年第10期11卷 2185-2187页

作者： Yang song Yongzhuang Liu Wanqing Zhao School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200444China School of Computing Newcastle UniversityNewcastle upon Tyne NE45TGUK

Dear Editor,This letter concerns the development of approximately bi-similar symbolic models for a discrete-time interconnected switched system(DT-ISS).The DT-ISS under consideration is formed by connecting multiple switched systems known as component switched systems(CSSs).Although the problem of constructing approximately bi-similar symbolic models for DT-ISS has been addressed in some literature,the previous works have relied on the assumption that all the subsystems of CSSs are incrementally input-state stable.

关键词： approximate symbolic connected