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Advanced modeling of the absorption enhancement of black carbon particles in chamber experiments by considering the morphology and coating thickness

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Frontiers of Environmental Science & engineering 2024年第9期18卷 129-142页

作者： Xiaodong Wei Jianlin Hu Chao Liu Xiaodong Xie Junjie Yin Song Guo Min Hu Jianfei Peng Huijun Wang Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science&TechnologyNanjing 210044China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Key Laboratory of Meteorological Disaster(Ministry of Education)Nanjing University of Information Science and TechnologyNanjing 210044China Nansen−Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China East China Air Traffic Management Bureau CAAC Shanghai 200335China State Key Joint Laboratory of Environmental Simulation and Pollution Control International Joint Laboratory for Regional Pollution Control(IJRC)(Ministry of Education)College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China Tianjin Key Laboratory of Urban Transport Emission Research&State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and EngineeringNankai UniversityTianjin 300071China

Measurements studies have shown that the absorption of radiation by black carbon(BC)increases as the particles ***,there are significant discrepancies between the measured and modeled absorption enhancement(E_(abs)),largely due to the simplifications used in modeling the mixing states and shape *** took advantage of chamber experiments on BC aging and developed an efficient method to resolve the particle shape based on the relationship between the coating fraction(ΔD_(ve)/D_(ve),0)and fractal dimension(D_(f)),which can also reflect the variations of D_(f)during the whole BC aging *** with externally and partly mixed states(0≤ΔD_(ve)/D_(ve),0≤0.5)can be considered to be uniformly distributed with the D_(f)values of 1.8–2.1,whereas the Df values are constrained in the range 2.2–2.8 for fully mixed states(ΔD_(ve)/D_(ve),0>0.5).The morphological parameters(i.e.,the effective density and the dynamic shape factor)were compared with the measured values to verify the simulated *** simulated mean deviations of morphological parameters were smaller than 8%for the method resolving the particle *** applying a realistic shape and refractive index,the mass absorption cross for fully mixed states can be improved by 11%compared with a simplified core–shell *** on our understanding of the influence of D_(f)andΔD_(ve)/D_(ve),0 on E_(abs),we propose a two-stage calibration equation to correct the E_(abs)values estimated by the core–shell model,which reduces the simulation error in the Mie calculation by 6%–14%.

关键词： Black carbon Mixing states Fractal dimension Dynamic shape factor Absorption enhancement

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Design and Performance Analysis of HMDV Dynamic Inertial Suspension Based on Active Disturbance Rejection control

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Computer Modeling in engineering & Sciences 2024年第8期140卷 1485-1506页

作者： Xiaofeng Yang Wei Wang Yujie Shen Changning Liu Tianyi Zhang School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China Automotive Engineering Research Institute Jiangsu UniversityZhenjiang212013China Chongqing Key Laboratory of Urban Rail Transit System Integration and Control Chongqing400074China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan universityChangsha410082China

This paper addresses the impact of vertical vibration negative effects,unbalanced radial forces generated by the static eccentricity of the hub motor,and road excitation on the suspension performance of Hub Motor Driven Vehicle(HMDV).A dynamic inertial suspension based on Active Disturbance Rejection control(ADRC)is proposed,combining the vertical dynamic characteristics of dynamic inertial suspension with the features of ADRC,which distinguishes between internal and external disturbances and arranges the transition ***,a simulation model of the static eccentricity of the hub motor is established to simulate the unbalanced radial electromagnetic force generated under static eccentricity.A quarter-vehicle model of an HMDV with a controllable dynamic inertial suspension is then ***,the passive suspension model is studied under different grades of road excitation,and the impact mechanism of suspension performance at speeds of 0–20 m/s is ***,the three main components within the ADRC controller are designed for the second-order controlled system,and optimization algorithms are used to optimize its internal ***,the performance of the traditional passive suspension,the PID-based controllable dynamic inertial suspension,and the ADRC-based controllable dynamic inertial suspension are analyzed under different road *** results show that,under sinusoidal road input,the ADRC-based controllable dynamic inertial suspension exhibits a 52.3%reduction in the low-frequency resonance peak in the vehicle body acceleration gain diagram compared to the traditional passive suspension,with significant performance optimization in the high-frequency *** random road input,the ADRC-based controllable dynamic inertial suspension achieves a 29.53%reduction in the root mean square value of vehicle body acceleration and a 14.87%reduction in dynamic tire *** indicates that the designed controllable dynamic inertia

关键词： HMDV static eccentricity ADRC dynamic inertial suspension road excitation

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Evolution hydrothermal aging resistance mechanism study of zirconium and manganese doped CeO_(2)catalysts in soot catalytic combustion based on low Miller indices crystal surface effect

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Journal of Rare Earths 2024年第7期42卷 1272-1281,I0003页

作者： Zonglin Li Pan Wang Hong Ni Chengcheng Ao Lidong Zhang Hefeng Zhang Kai Li School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental ScienceBeijing100012China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230026China

The thermogravimetric analysis(TGA)experiments were carried out to reveal the mechanism of Zr and Mn doping on catalytic activity of CeO_(2)catalyst both fresh and after hydrothermal aging,and the lattice morphology and valence changes were characterized by means of Brunauer-Emmett-Teller(BET)method,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and H_(2)-temperature programmed reduction(H_(2)-TPR).Density functional theory(DFT)and molecular thermodynamics calculations were applied to investigate the change in catalytic activity,crystal surface energy and crystal morphology caused by hydrothermal *** maximum reaction rate temperature of fresh Mn/CeO_(2)(389℃)is similar to that of CeO_(2)(371℃)and lower than that of Zr/CeO_(2)(447℃),but the catalytic performance of CeO_(2)decreases more severely after hydrothermal *** catalyst crystals show different degrees of crystal surface migration after hydrothermal aging,which leads to the reduction of Ce^(3+)/Ce^(4+) ratio and the active sites *** calculations indicate that the doping of Zr and Mn reduces the surface energy of the low Miller indices surface and increases the oxygen vacancy formation energy,leading to better thermal stability and lower catalytic *** Zr and Mn doping also changes the adsorption energy and Gibbs free energy of H_(2)O,which dominates the migration of(111)to(110)and(100)in the vapor *** crystal surface migration mechanism of CeO_(2)catalysts doped with Zr and Mn induced by H_(2)O molecules at high temperature obtained in this study can provide a valuable addition to the regeneration of CeO_(2)catalysts in the after-treatment systems of diesel engines.

关键词： Soot CeO_(2)-based catalyst CDPF Rare earth metal oxides DFT calculations

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Highly constrained cooperative guidance for flexible landing on asteroids

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Chinese Journal of Aeronautics 2025年第4期38卷 349-360页

作者： Chang LYU Zixuan LIANG Shengying ZHU School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Autonomous Navigation and Control for Deep Space Exploration(Beijing Institute of Technology) Ministry of Industry and Information TechnologyBeijing 100081China

Flexible lander,composed of multiple nodes connected by flexible material,can reducethe bouncing and overturning during the asteroid *** satisfy the complex constraints inthe node cooperation of the flexible landing,an intelligent cooperative guidance method is *** method consists of a double-layer cooperative guidance structure,a guidance parameterdetermination approach,and an action priority *** double-layer contains a basic guid-ance used to satisfy the terminal state constraints,and a compensatory guidance used to satisfythe lander's attitude *** the compensatory guidance,the parameters are determinedby multi-agent system,which are trained according to the performance index of flexible landing *** action priority strategy is used to reduce the detrimental effect of parameter inconsis-tency on the node *** simulation of flexible landing shows that the cooperativeguidance method is effective in improving the landing accuracy while satisfying the ***,the method is robust to the disturbance in the navigation and control.

关键词： Asteroid Flexible lander Multi-constraint Cooperative guidance Reinforcement learning

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Multi-party semi-quantum private comparison protocol of size relation based on two-dimensional Bell states

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Chinese Physics B 2024年第11期33卷 184-192页

作者： Bing Wang Li-Hua Gong San-Qiu Liu Jiangxi Province Key Laboratory of Fusion and Information Control Department of PhysicsNanchang UniversityNanchang 330031China School of Physics and Materials Nanchang UniversityNanchang 330031China Department of Electronic Information Engineering Nanchang UniversityNanchang 330031China

Currently,all quantum private comparison protocols based on two-dimensional quantum states can only compare equality,via using high-dimensional quantum states that it is possible to compare the size relation in existing *** addition,it is difficult to manipulate high-dimensional quantum states under the existing conditions of quantum information processing,leading to low practicality and engineering feasibility of protocols for comparing size *** this situation,we propose an innovative *** proposed protocol can make size comparison by exploiting more manageable two-dimensional Bell states,which significantly enhances its feasibility with current quantum ***,the proposed protocol enables multiple participants to compare their privacies with the semi-quantum *** communication process of the protocol is simulated on the IBM Quantum Experience platform to verify its *** analysis shows that the proposed protocol can withstand common attacks while preserving the privacies of all ***,the devised protocol may provide an important reference for implementation of quantum private size comparison protocols.

关键词： two-dimensional Bell state size relation multi-party semi-quantum private comparison

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Pedestrian object detection algorithm based on lightweight YOLOv7 in complex street scenarios

Pedestrian object detection algorithm based on lightweight Y...

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2023 International Conference on Algorithm, Imaging Processing, and Machine Vision, AIPMV 2023

作者： Cheng, Shangqi Niu, Hongxia Key Laboratory of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong University Lanzhou730070 China Key Laboratory of Plateau Traffic Information Engineering and Control of Gansu Province Lanzhou730070 China School of Automation and Electrical Engineering Lanzhou Jiaotong University Lanzhou730070 China

ISBN: (纸本)9781510672444

In view of the problems of excessive parameter setting and large calculation of YOLOv7 in pedestrian object detection in complex street scenarios, this paper proposes a lightweight method to improve YOLOv7 algorithm. Under the YOLOv7 framework, Partial Convolution (PConv) is integrated into the convolution of the original algorithm, replacing part of the convolution in the original convolution layer, and the SEAttention attention module is introduced to ensure the detection accuracy of the lightweight algorithm. The experimental results on the home-made data set show that, compared with the original YOLOv7 algorithm, the number of model parameters decreased by 11.0% in the improved YOLOv7 algorithm, and the algorithm calculation volume decreased by 19.4%, while ensuring the high accuracy of the original YOLOv7 algorithm. In this paper, the algorithm reduces the number of parameters and calculations, and achieves the balance of lightweight and accuracy. © 2024 SPIE.

关键词： Convolution

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Reliability evaluation method of vehicle on-board controller of train control system based on Hawkes process 14

Reliability evaluation method of vehicle on-board controller...

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14th IEEE Global Reliability and Prognostics and Health Management Conference, PHM-Hangzhou 2023

作者： Peng, Cong Wang, Zongyao Wei, ShangGuan Chai, Linguo Peng, Jiali Cai, Baigen School of Electronic and Information Engineering Beijing Jiaotong University Beijing China School of Electronic and Information Engineering The State Key Laboratory Rail Traffic Control Beijing Jiaotong University Beijing China

ISBN: (纸本)9798350301359

Reliability assessment is an important approach to reduce the risk of equipment failure, improve operational quality, and reduce life-cycle costs. Based on the real fault event of a certain operation line of urban rail transit, a reliability assessment method based on the Hawkes process is proposed. The Hawkes process is used to mathematically derive the reliability function of the vehicle on-board controller equipment for the train control system. The maximum likelihood estimation and genetic algorithm are used to optimize the parameters of the Hawkes process, and sensitivity of three important parameters is analyzed. The corresponding maintenance recommendations are also given. The research results show that the fitness function of parameter estimation of the Hawkes process reaches its optimum at the 7th iteration, and the reliability curve of the vehicle on-board controller equipment can be divided into three stages based on two time points of 2 months and 1 year. The mean time to failure of the equipment can be calculated using a formula and is approximately 217 days. During the first 2 months of operation, due to defects in design, raw materials, and manufacturing processes, the reliability of the equipment decreases rapidly. Therefore, it is necessary to increase the trial operation time of the equipment to ensure a smooth start-up. During the period of 2 months to 1 year of operation, the equipment operates more smoothly, and the rate of decrease in reliability is slower. Daily maintenance should be carried out to check for any abnormal equipment operating conditions. After operating for more than 1 year, equipment failures occur frequently, and the rate of decrease in reliability is fast. Therefore, the equipment should be repaired or replaced as necessary to ensure safe, stable, and efficient operation. Through sensitivity analysis of the three important parameters in the reliability assessment process, it is found that parameter β is positively correlated

关键词： component: Train control System Genetic Algorithm Hawkes Process Reliability Assessment Vehicle On-board controller

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Dipole-moment modulation of photovoltaic and photoresponse properties in 2H-MoSSe/MoS2 van der Waals heterojunctions under electric field

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Science China(information Sciences) 2025年第5期68卷 417-418页

作者： Yinkang WANG Meng GE Jianing TAN Biao CAI Gang OUYANG Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Key Laboratory for Matter Microstructure and Function of Hunan ProvinceHunan Normal University All-solid-state Energy Storage Materials and Devices Key Laboratory of Hunan Province College of Information and Electronic Engineering Hunan City University

The intrinsic dipole moment introduces a novel degree of freedom for engineering the photoelectric properties of twodimensional （2D） Janus transition metal dichalcogenides（J-TMDs）-based van der Waals heterojunctions （vdWHs）[1,2].However,the theoretical relationship and underlying modulation mechanisms governing the photoelectric properties of J-TMD-based vdWHs under external electric fields（E-fields） remain unclear,hindering the advancement of nanoscale optoelectronic ***,we develop a theoretical model and investigate the combined effects of intrinsic dipole and external E-fields on the photoelectric properties of 2H-MoSSe/*** approach integrates the atomic-bond-relaxation （ABR） method [3],Marcus theory [4],detailed balance principle （DBP）[5],and ab initio nonadiabatic molecular dynamics （NAMD） simulations.

关键词：

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Damage effect and progressive failure mechanism of sandstone considering different flaw angles under dynamic loading

Rock Mechanics Bulletin

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Rock Mechanics Bulletin 2024年第1期3卷 81-96页

作者： Dongliang Ji Hui Cheng Hongbao Zhao State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuangChina Key Laboratory of Mechanical Behavior Evolution and Control of Traffic Engineering Structures in Hebei Shijiazhuang Tiedao UniversityShijiazhuangChina School of Energy and Mining Engineering China University of Mining and Technology(Beijing)BeijingChina

In many engineering applications,it is essential to have information about rocks that inherently contain preexisting flaws under dynamic loading *** impact tests are conducted on samples with varying flaw angles using the split Hopkinson pressure bar(SHPB)test system and the Digital Image Correlation system(DIC).The characteristics of the samples after dynamic loading,including dynamic strength,energy dissipation,and fractal fracture,are compared and *** the flaw angle increases,the peak stress and strain exhibit a typical V-shaped pattern,reaching the minimum value at 30,and the initial initiation position shifts from the flaw tips to the middle of the *** modes can be divided into three modes depending on the flaw *** progressive failure process,taking into account the heterogeneity of the rock,is demonstrated by developing an elastic damage constitutive model that uses dynamic compression and tensile tests to parameterize *** the flaw angle increases,the initial damage zone also moves from the flaw tips to the middle of the *** around the hole with redistributed stress are observed,and the failure mechanisms can be explained with the aid of strain energy density(SED).Using fracture mechanics,the analytical solution of stress around the flaw is provided,and the variation of crack initiation angle,stress distribution,and energy dissipation under different flaw angles is theoretically explained,which is in good agreement with the experimental and simulated results.

关键词： Dynamic loading Damage evolution Constitutive model Flaw angle Energy dissipation

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Contour Detection Algorithm forαPhase Structure of TB6 Titanium Alloy fused with Multi-Scale Fretting Features

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Chinese Journal of Mechanical engineering 2024年第5期37卷 499-509页

作者： Fei He Yan Dou Xiaoying Zhang Lele Zhang School of Information Science and Engineering Yanshan UniversityQinhuangdao 066004China Hebei Provincial Key Laboratory of Software Engineering Yan shan University Qinhuangdao 066004China School of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China

Aiming at the problems of inaccuracy in detecting theαphase contour of TB6 titanium *** combining computer vision technology with human vision mechanisms,the spatial characteristics of theαphase can be simulated to obtain the contour ***,an algorithm forαphase contour detection of TB6 titanium alloy fused with multi-scale fretting features is ***,through the response of the classical receptive field model based on fretting and the suppression of new non-classical receptive field model based on fretting,the information maps of theαphase contour of the TB6 titanium alloy at different scales are obtained;then the information map of the smallest scale contour is used as a benchmark,the neighborhood is constructed to judge the deviation of other scale contour information,and the corresponding weight value is calculated;finally,Gaussian function is used to weight and fuse the deviation information,and the contour detection result of TB6 titanium alloyαphase is *** the Visual Studio 2013 environment,484 metallographic images with different temperatures,strain rates,and magnifications were *** results show that the performance evaluation F value of the proposed algorithm is 0.915,which can effectively improve the accuracy ofαphase contour detection of TB6 titanium alloy.

关键词： TB6 titanium alloyαphase Multi-scale fretting features Contour detection

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