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Low-Temperature Reforming Products Coupling Spark Plug on Gasoline Compression Ignition and Combustion Characteristics under Low-Load Condition

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Journal of Thermal Science 2024年第06期33卷 2386-2398页

作者： LIU Long LI Mingkun CAO Qun WANG Yang WANG Xichang college of {1. and Energy engineering Harbin Engineering University China Helicopter Research and Development Institute

Gasoline compression combustion engine has the advantages of low emission and high efficiency,which is very promising for research,but it is difficult to apply under low-load *** has the characteristics of low reactivity;in the case of low thermodynamic state in the cylinder,the fire delay period of the fuel is longer,and the combustion phase is relatively lagging,which will lead to the increase of combustion cycle fluctuations,and even difficult to ignite and other adverse combustion *** order to improve the combustion stability of Gasoline Compression Ignition（GCI） engine under low-load condition and expand the limit of low-load combustion boundary,gasoline was reformed without catalyst under the boundary condition of reforming temperature of 488 K and reforming equivalent ratio of 8,and the concentration of reformed product was measured by a gas detection ***,the coupling of the reformed product and spark plug with GCI engine under low-load condition was investigated to analyze the effect on engine combustion and *** results showed that the initial combustion timing of the low-load GCI engine was late,but the addition of reformed products could advance the combustion phase,shorten the combustion duration,reduce single-cycle NOxemission,and improve the small-load operation characteristics of GCI *** spark plug ignition on the basis of adding reformed products could further improve the problem of combustion stability under low-load GCI *** the optimization effect became more obvious as the ignition position of the spark plug moves ***,spark plug ignition would cause local high temperature areas,resulting in an increase in NOxemission.

关键词： combustion emission gasoline low-temperature reform spark plug

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A module based modeling framework for estimating lunar dust deposition due to human activities

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Chinese Journal of Aeronautics 2024年第2期37卷 501-510页

作者： Chunjian PAN college of Automation {1. Shanghai University of Electric PowerShanghai 200090China

Lunar dust is considered to be one of the top challenges for enabling humans to have extended stays on the *** activities such as module landings and launches,walking,rover operation and construction activities will inevitably produce a significant amount of ***,it is important to estimate the potential range and intensity of dust deposition caused by these activities to minimize dust accumulation over time and for maintenance planning and execution.A modular model that correlates the dust deposition distribution with initial mean dust particle velocity,its mean ejected angle and the total amount of ejected mass is developed for an elementary mechanical *** modular model is further employed to form a modeling framework to estimate dust deposition of a trajectory based activity of similar repeated movements such as the landing process of a lander,walking and rover *** model forms a unified modeling framework for different trajectory-based activities and is shown to predict consistent and physically meaningful ranges and intensities of dust deposition provided reliable data to calibrate the model parameters.

关键词： Lunar dust Dust deposition Lunar lander Lunar construction Model calibration

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A Blockchain-Based Access Control Scheme for Reputation Value Attributes of the Internet of Things

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Computers, Materials & Continua 2024年第1期78卷 1297-1310页

作者： Hongliang Tian Junyuan Tian college of Electrical {1. Northeast Electric Power UniversityJilin132012China

The Internet of Things(IoT)access controlmechanism may encounter security issues such as single point of failure and data *** address these issues,a blockchain-based IoT reputation value attribute access control scheme is ***,writing the reputation value as an attribute into the access control policy,and then deploying the access control policy in the smart contract of the blockchain system can enable the system to provide more fine-grained access control;Secondly,storing a large amount of resources fromthe Internet of Things in Inter Planetary File System(IPFS)to improve system throughput;Finally,map resource access operations to qualification tokens to improve the performance of the access control *** simulation experiments based on the Hyperledger Fabric *** simulation experimental results,it can be seen that the access control system can achieve more fine-grained and dynamic access control while maintaining high throughput and low time delay,providing sufficient reliability and security for access control of IoT devices.

关键词： Blockchain IoT access control Hyperledger Fabric

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An Energy Trading Method Based on Alliance Blockchain and Multi-Signature

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Computers, Materials & Continua 2024年第2期78卷 1611-1629页

作者： Hongliang Tian Jiaming Wang college of Electrical {1. Northeast Electric Power UniversityJilin132012China

Blockchain,known for its secure encrypted ledger,has garnered attention in financial and data transfer realms,including the field of energy ***,the decentralized nature and identity anonymity of user nodes raise uncertainties in energy *** broadcast consensus authentication slows transaction speeds,and frequent single-point transactions in multi-node settings pose key exposure risks without protective measures during user *** address these,an alliance blockchain scheme is proposed,reducing the resource-intensive identity verification among *** integrates multi-signature functionality to fortify user resources and transac-tion security.A novel multi-signature process within this framework involves neutral nodes established through central *** neutral nodes participate in multi-signature’s signing and verification,ensuring user identity and transaction content *** interactions among user nodes enhances transaction efficiency by minimizing communication overhead during verification and consensus *** assessments on reliability and operational speed highlight superior security performance,resilient against conventional attack *** shows that compared to traditional solutions,this scheme has advantages in terms of running *** conclusion,the alliance blockchain framework introduces a novel approach to tackle blockchain’s limitations in energy *** integrated multi-signature process,involving neutral nodes,significantly enhances security and *** scheme’s efficiency,validated through analytical assessments and simulations,indicates robustness against security threats and improved transactional *** research underscores the potential for improved security and efficiency in blockchain-enabled energy trading systems.

关键词： Alliance blockchain multi-signature energy trading security performance transaction efficiency

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Securing offshore resources development: A mathematical investigation into gas leakage in long-distance flexible pipes

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Petroleum Science 2024年第4期21卷 2734-2744页

作者： Xiang-An Lu Liang-Liang Jiang Jian-Sheng Zhang Min-Gui Wang Guangling college of Yangzhou University Department of Chemical and Petroleum engineering University of Calgary Department of Energy and power {1. Tsinghua University

Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development. Under high pressure conditions, small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space, incurring annular pressure build-up and/or production of acidic environment, which poses serious challenges to the structure and integrity of the flexible pipes. Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature, annular structure, external temperature. In a long-distance gas flexible pipe, moreover, gas permeation exhibits non-uniform features, and the gas permeated into the annular space flows along the metal gap. To assess the complex gas transport behavior in long-distance gas flexible pipes, a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes, the diffusion of gas in the inner liner, and the gas seepage in the annular space under varying permeable properties of the annulus. In addition, the effect of a variable temperature is accounted. A numerical calculation method is accordingly constructed to solve the coupling mathematical equations. The annular permeability was shown to significantly influence the distribution of annular pressure. As permeability increases, the annular pressure tends to become more uniform, and the annular pressure at the wellhead rises more rapidly. After annular pressure relief followed by shut-in, the pressure increase follows a convex function. By simulating the pressure recovery pattern after pressure relief and comparing it with test results, we deduce that the annular permeability lies between 1.3 and 51. m D. The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.

关键词： Offshore resources development Transport security Long-distance flexible pipes Gas leakage Heat and mass transfer model Finite difference calculation

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Novel high-safety aeroengine performance predictive control method based on adaptive tracking weight

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Chinese Journal of Aeronautics 2024年第7期37卷 352-374页

作者： Qian CHEN Hanlin SHENG Jie ZHANG Jiacheng LI college of Energy and {1. engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China college of Automation {1. Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Increasing attention has been attracted to the dynamic performance and safety of advanced performance predictive control systems of the next-generation *** latest research demonstrates that Subspace-based Improved Model Predictive Control(SIMPC)can overcome the difficulty in solving the predictive model in MPC/NMPC ***,applying constant design parameters cannot maintain consistent control effects in all ***,the designed system relies too much on sensor-measured data,and thus it is difficult to thoroughly validate the safety of the system because of its high *** means that any potential hardware/software faults will endanger the ***,this paper first presents a novel nonlinear mapping relationship to adaptively tune the tracking weight online with the change of power Lever Angle(PLA)and real-time relative tracking ***,without introducing additional design parameters,an Adaptive Tracking Weight-based SIMPC(ATW-SIMPC)controller is designed to improve the control performance in all operating states ***,a Primary/Backup Hybrid Control(PBHC)strategy with the ATW-SIMPC controller as the primary system and the traditional speed(Nf)controller as the backup system is proposed to ensure *** designed affiliated switching controller and the real-time monitor therein can be used to realize reasonable and smooth switching between primary/backup systems,so as to avoid bump *** PBHC system switches to the Nf controller when the ATW-SIMPC controller is wrong because of potential hardware/software faults;otherwise,the ATW-SIMPC controller keeps acting on the *** main results prove that the ATW-SIMPC controller with the optimal nonlinear mapping relationship,compared with the existing SIMPC controller,uplifts the dynamic control performance by 32%and reduces overshoots to an allowable limit,resulting in a better control effect in full *** comparison results consistently i

关键词： Aeroengine Model predictive control Hybrid system Adaptive weight Safety

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Sparse Adversarial Learning for FDIA Attack Sample Generation in Distributed Smart

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Computer Modeling in engineering & Sciences 2024年第5期139卷 2095-2115页

作者： Fengyong Li Weicheng Shen Zhongqin Bi Xiangjing Su college of Computer Science and Technology Shanghai University of Electric PowerShanghai201306China college of Electrical {1. Shanghai University of Electric PowerShanghai201306China

False data injection attack(FDIA)is an attack that affects the stability of grid cyber-physical system(GCPS)by evading the detecting mechanism of bad *** FDIA detection methods usually employ complex neural networkmodels to detect FDIA ***,they overlook the fact that FDIA attack samples at public-private network edges are extremely sparse,making it difficult for neural network models to obtain sufficient samples to construct a robust detection *** address this problem,this paper designs an efficient sample generative adversarial model of FDIA attack in public-private network edge,which can effectively bypass the detectionmodel to threaten the power grid system.A generative adversarial network(GAN)framework is first constructed by combining residual networks(ResNet)with fully connected networks(FCN).Then,a sparse adversarial learning model is built by integrating the time-aligned data and normal data,which is used to learn the distribution characteristics between normal data and attack data through iterative ***,we introduce a Gaussian hybrid distributionmatrix by aggregating the network structure of attack data characteristics and normal data characteristics,which can connect and calculate FDIA data with normal ***,efficient FDIA attack samples can be sequentially generated through interactive adversarial *** simulation experiments are conducted with IEEE 1.-bus and IEEE 1.8-bus system data,and the results demonstrate that the generated attack samples of the proposed model can present superior performance compared to state-of-the-art models in terms of attack strength,robustness,and covert capability.

关键词： Distributed smart grid FDIA adversarial learning power public-private network edge

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Mode Switching and Consistency Control for Electric-Hydraulic Hybrid Steering System

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Automotive Innovation 2024年第1期7卷 166-181页

作者： Zhongkai Luan Wanzhong Zhao Chunyan Wang college of Energy and {1. engineering 29 Yudao St.Nanjing 210016China

Electric-hydraulic hybrid power steering(E-HHPS)system,a novel device with multiple modes for commercial electric vehicles,is designed to realize both superior steering feel and high energy ***,inconsistent steering perfor-mance occurs in the mode-switching process due to different dynamic characteristics of electric and hydraulic components,which even threatens driving *** this paper,mode-switching strategy and dynamic compensation control method are proposed for the E-HHPS system to eliminate the inconsistency of steering feel,which comprehensively considers ideal assistance characteristics and energy consumption of the ***,the influence of disturbances on system stability is analyzed,and H_(∞)robust controller is employed to guarantee system robustness and *** experimental results dem-onstrate that the proposed strategy can provide a steering system with natural steering feel without apparent inconsistency and effectively minimize energy consumption.

关键词： Hydraulic hybrid steering system Steering feel Consistency Mode switch Robust control

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Numerical Prediction of Ride Comfort of Tracked Vehicle Equipped with Novel Flexible Road Wheels

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Chinese Journal of Mechanical engineering 2024年第4期37卷 277-289页

作者： Yaoji Deng Zhiyue Wang Youqun Zhao Junjie Gong Hui Shen Fen Lin college of Mechanical {1. Yangzhou UniversityYangzhou 225127China college of Energy and {1. engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Enhancing ride comfort has always constituted a crucial focus in the design and research of modern tracked vehicles,heavily reliant on the driving system's *** the road wheel is a key component of the driving system,traditional road wheels predominantly adopt a solid structure,exhibiting subpar adhesion performance and damping effects,thereby falling short of meeting the demands for high-speed,stable,and long-distance driving in tracked *** this issue,this paper proposes a novel type of flexible road wheel(FRW)characterized by a catenary *** study investigates the ride comfort of tracked vehicles equipped with flexible road wheels by integrating finite element and vehicle ***,three-dimensional(3D)finite element(FE)models of both flexible and rigid road wheels are established,considering material and contact *** models are validated through a wheel radial loading *** on the validated FE model,the paper uncovers the relationship between load and radial deformation of the road wheel,forming the basis for a nonlinear mathematical ***,a half-car model of a tracked vehicle with seven degrees of freedom is established using Newton's second law.A random road model,considering the track effect and employing white noise,is *** study concludes by examining the ride comfort of tracked vehicles equipped with flexible and rigid road wheels under various speeds and road *** results demonstrate that,in comparison to the rigid road wheel(RRW),the flexible road wheel enhances the ride comfort of tracked vehicles on randomly uneven *** research provides a theoretical foundation for the implementation of flexible road wheels in tracked vehicles.

关键词： Ride comfort Flexible road wheel Finite element model Dynamic model Tracked vehicle

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Hovering rotor aerodynamics in extreme ground effect

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Chinese Journal of Aeronautics 2024年第7期37卷 204-219页

作者： Zhenlong WU Tianyu ZHANG Huijun TAN Haoyu ZHOU Wei CHEN Maixiang XIE college of Energy and {1. engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China China Aviation power Machinery Research Institute Zhuzhou 412002China

This paper presents an experimental and numerical study of the aerodynamics of a moderate-scale rotor hovering in the Extreme Ground Effect(EGE)where rotor height-offground is below half the rotor *** tip vortex field was visualized by using the PIV *** aerodynamic performance,tip vortex trajectory,wall jet characteristics,surface pressure and velocity fields were measured and *** explore more deeply the flow mechanisms of the extreme ground effect,Detached Eddy Simulation(DES)was conducted on completely structured *** results showed significant deviations of the rotor performance in EGE from that in Regular Ground Effect(RGE)with the rotor heights of more than half the rotor ***,the flow structures of the rotor in EGE are considerably complex,such as the wall jet and groundwash flow *** rotor wake flow and tip vortices impact the ground more frequently,resulting in distinctive characteristics of the surface pressure and velocity fields in EGE.

关键词： Rotor Ground effect Tip vortex Detached Eddy Simulation(DES) Groundwash

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