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Surrogate modeling for unsaturated infiltration via the physics and equality-constrained artificial neural networks

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Journal of Rock Mechanics and Geotechnical engineering 2024年第6期16卷 2282-2295页

作者： peng Lan Jingjing Su Sheng zhang School of Civil engineering Central South UniversityChangsha410075China Discipline of Civil Surveying and Environmental EngineeringPriority Research Centre for Geotechnical Science and EngineeringThe University of NewcastleCallaghanNSW2308Australia Qinghai University Qinghai810016China

Machine learning(ML)provides a new surrogate method for investigating groundwater flow dynamics in unsaturated *** pure data-driven methods(*** neural network,DNN)can provide rapid predictions,but they do require sufficient on-site data for accurate training,and lack interpretability to the physical processes within the *** this paper,we provide a physics and equalityconstrained artificial neural network(PeCANN),to derive unsaturated infiltration solutions with a small amount of initial and boundary *** takes the physics-informed neural network(PINN)as a foundation,encodes the unsaturated infiltration physical laws(*** equation,Re)into the loss function,and uses the augmented Lagrangian method to constrain the learning process of the solutions of Re by adding stronger penalty for the initial and boundary *** unsaturated infiltration cases are designed to test the training performance of PeCANN,***-dimensional(1D)steady-state unsaturated infiltration,1D transient-state infiltration,two-dimensional(2D)transient-state infiltration,and 1D coupled unsaturated infiltration and *** predicted results of PeCANN are compared with the finite difference solutions or analytical *** results indicate that PeCANN can accurately capture the variations of pressure head during the unsaturated infiltration,and present higher precision and robustness than DNN and *** is also revealed that PeCANN can achieve the same accuracy as the finite difference method with fewer initial and boundary training ***,we investigate the effect of the hyperparameters of PeCANN on solving Re *** provides an effective tool for simulating unsaturated infiltration.

关键词： Richards equation(Re) Unsaturated infiltration Data-driven solutions Numerical modeling Machine learning(ML)

Density functional theory study of B- and Si-doped carbons and their adsorption interactions with sulfur compounds

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Carbon energy 2024年第2期6卷 195-208页

作者： peng Guo Hong zhang Shuliang Dong Libao An College of Mechanical engineering North China University of Science and TechnologyTangshanHebeiChina College of Life Sciences North China University of Science and TechnologyTangshanHebeiChina

Understanding the adsorption interactions between carbon materials and sulfur compounds has far-reaching impacts,in addition to their well-known important role in energy storage and conversion,such as lithium-ion *** this paper,properties of intrinsic B or Si single-atom doped,and B-Si codoped graphene(GR)and graphdiyne(GDY)were investigated by using density functional theory-based calculations,in which the optimal doping configurations were explored for potential applications in adsorbing sulfur *** showed that both B or Si single-atom doping and B-Si codoping could substantially enhance the electron transport properties of GR and GDY,improving their surface ***,B and Si atoms displayed synergistic effects for the codoped configurations,where B-Si codoped GR/GDY exhibited much better performance in the adsorption of sulfurcontaining chemicals than single-atom doped *** addition,results demonstrated that,after B-Si codoping,the adsorption energy and charge transfer amounts of GDY with sulfur compounds were much larger than those of GR,indicating that B-Si codoped GDY might be a favorable material for more effectively interacting with sulfur reagents.

关键词： adsorption density functional theory doping graphdiyne graphene sulfur compounds

A self-organization formation configuration based assignment probability and collision detection

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Journal of Systems engineering and electronics 2024年第1期35卷 222-232页

作者： SONG Wei WANG Tong YANG Guangxin zhang peng School of Harbin engineering University Harbin 150001China Chinese Aeronautical establishment Beijing 100010China

The formation control of multiple unmanned aerial vehicles(multi-UAVs)has always been a research *** on the straight line trajectory,a multi-UAVs target point assignment algorithm based on the assignment probability is proposed to achieve the shortest overall formation path of multi-UAVs with low complexity and reduce the energy *** order to avoid the collision between UAVs in the formation process,the concept of safety ball is introduced,and the collision detection based on continuous motion of two time slots and the lane occupation detection after motion is proposed to avoid collision between *** on the idea of game theory,a method of UAV motion form setting based on the maximization of interests is proposed,including the maximization of self-interest and the maximization of formation interest is proposed,so that multi-UAVs can complete the formation task quickly and reasonably with the linear trajectory assigned in ***,through simulation verification,the multi-UAVs target assignment algorithm based on the assignment probability proposed in this paper can effectively reduce the total path length,and the UAV motion selection method based on the maximization interests can effectively complete the task formation.

关键词： straight line trajectory assignment probability collision detection lane occupation detection maximization of interests

Improved spatio-temporal alignment measurement method for hull deformation

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Journal of Systems engineering and electronics 2024年第2期35卷 485-494页

作者： XU Dongsheng YU Yuanjin zhang Xiaoli peng Xiafu School of Automation Beijing Institute of TechnologyBeijing 100081China School of Aerospace engineering Xiamen UniversityXiamen 361005China

In this paper,an improved spatio-temporal alignment measurement method is presented to address the inertial matching measurement of hull deformation under the coexistence of time delay and large misalignment *** misalignment angle and time delay often occur simultaneously and bring great challenges to the accurate measurement of hull deformation in space and *** proposed method utilizes coarse alignment with large misalignment angle and time delay estimation of inertial measurement unit modeling to establish a brand-new spatiotemporal aligned hull deformation measurement *** addition,two-step loop control is designed to ensure the accurate description of dynamic deformation angle and static deformation angle by the time-space alignment method of hull *** experiments illustrate that the proposed method can effectively measure the hull deformation angle when time delay and large misalignment angle coexist.

关键词： inertial measurement spatio-temporal alignment hull deformation

Coupled funnel control for supersonic tailless aerial vehicle on penetrating counter air

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Chinese Journal of Aeronautics 2024年第7期37卷 458-481页

作者： Yingyang WANG peng zhang Jilian GUO Jianbo HU equipment Management and Unmanned Aerial Vehicle engineering School Air Force Engineering UniversityXi’an 710051China Aviation engineering School Air Force Engineering UniversityXi’an 710038China

Supersonic Tailless Aerial Vehicles(STAVs)will become an essential force in Penetrating Counter Air(PCA),but STAVs do not have the traditional horizontal and vertical tails,making pitch and yaw control *** attack angle and the sideslip angle need to be limited to ensure that the engine inlet and the aerodynamic rudder at the rear of the vehicle can work properly,which is the so-called security *** addition,the tracking error of the aerodynamic angle needs to be limited to achieve effective attitude control or high-accuracy tracking of trajectories,which is the so-called performance *** this end,an attitude control method that meets the needs of PCA has been devised,based on constraint definition,coupled constraints handling,and control law ***,mathematical descriptions of the security constraints,performance constraints,and control constraints are ***,two treatment methods,coupled command filter and coupled funnel control are proposed for the aerodynamic angle coupled constraint ***,based on Nonlinear Dynamic Inverse(NDI)design,the coupled funnel controller is designed and validated by simulation for two typical mission scenarios,high-altitude penetration and low-altitude surprise *** proposed control method not only satisfies the security and performance constraints of STAV attitude control but also is highly robust.

关键词： Supersonic tailless aircraft Penetrating counter air Funnel control Attitude control Control allocation

Unveiling the protective role of biofilm formation on the photoaging of microplastics

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Science China Technological Sciences 2024年第10期67卷 3067-3078页

作者： zhang HaiYu LIU peng zhang JiaYu DAI JiaMin zhang XinRui zhang ZiXuan JIA HanZhong Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of AgricultureCollege of Natural Resources and EnvironmentNorthwest A&F University Key Laboratory of Organic Compound Pollution Control engineering School of Environmental and Chemical EngineeringShanghai University

In natural water, microplastics（MPs） inevitably undergo microbial colonization to form biofilm, while the effect of biofilm formation on the photoaging of MPs remains unknown. This study systematically investigated the photoaging behavior of disposable box-derived polypropylene（PPMPs） and polystyrene（PSMPs） mediated by formed biofilm in water. After incubating in Weihe water samples for 105 d, the biofilm was validated to form in PPMPs and PSMPs, with higher formation in PSMPs. In particular, biofilm formation inhibited the photoaging of PPMPs and PSMPs, with an 11.1% and 50.6% decrease in photooxidation compared to their virgin counterparts after 20 d of ultraviolet（UV） irradiation. Moreover, the photoaging route of MPs such as the reaction priority of functional groups（e.g., C–H, C=O, and benzene ring） was altered, indicating the important role of biofilm formation in the photoaging process of MPs. The protective effect of the biofilm was mainly caused by the role of optical light filters that absorbed UV energy by sacrificing themselves. Also, as the main attacker on MPs, the production of reactive oxygen species（ROS, mainly1O2and ·OH） was inhibited by biofilm, which was mainly responsible for the decreased photoaging of MPs. This study revealed the important role of biofilm in the photoaging process of MPs and suggested a higher resistance of（micro）plastics in natural water than that in the laboratory using pure MPs, which contributed to a deeper understanding of the environmental fate and pollution of MPs.

关键词： microplastics biofilm photoaging physical shielding reactive oxygen species

Intensified warming suppressed the snowmelt in the Tibetan Plateau

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Advances in Climate Change Research 2024年第3期15卷 452-463页

作者： Xiang LI peng CUI Xue-Qin zhang Fang zhang Key Lab of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China China‒Pakistan Joint Research Center on earth Sciences Chinese Academy of Sciences and Higher Education CommissionIslamabad 45320Pakistan

Understanding how hydrological factors interrelate is crucial when examining the impact of climate warming on ***,these connections are often overlooked,leading to an unclear relationship between temperature and *** study investigates the complex interplay between temperature and snowmelt in the Tibetan Plateau from 1961 to 2020,focusing on how extreme high-temperature events affect the frequency of extreme *** a structural equation model,we detected three temperature-related factors that predominantly influenced snowmelt and extreme *** annual average temperature was found to have a significant indirect impact on snowmelt,mediated by changes in snowfall,snow depth and snow *** contrast,high-temperature days(daily maximum temperatures exceeding the 90th percentile)and heat waves(at least three consecutive high-temperature days)negatively affected extreme snowmelt directly or *** direct effect of increasing extreme temperature events was associated with an earlier onset of high-temperature periods,which accelerated snowmelt and shortened the duration of extreme snowmelt ***,the reduction in snow cover owing to warming emerged as a main factor suppressing snowmelt and extreme snowmelt *** also revealed spatiotemporal variations in the temperature‒snowmelt relationship that highly depended on changes in snowmelt *** study elucidated why warming suppresses snowmelt and extreme snowmelt events in the Tibetan Plateau,highlighting the mediating roles of snow-related and phenological *** findings will provide scientific support for climate simulation and water management policymaking in alpine regions worldwide.

关键词： Climate change extreme temperature Snowmelt Structural equation model Tibetan Plateau

3D Foam-Based MXene Architectures:Structural and electrolytic engineering for Advanced Potassium-Ion Storage

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energy & environmental Materials 2024年第4期7卷 64-73页

作者： peng zhang Yanmeng peng Qizhen Zhu Razium Ali Soomro Ning Sun Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical Technology Beijing Advanced Innovation Centre for Soft Matter Science and engineering Beijing University of Chemical Technology

MXenes are emerging rapidly as promising electrode materials for energy storage due to their high electronic conductivity and rich surface chemistry,but their potassium storage performance is unsatisfactory because of... 详细信息

关键词： 3D foam-like scaffold electrolyte chemistry electrostatic neutralization MXene potassium-ion batteries

Real-time hybrid method for maneuver detection and estimation of non-cooperative space targets

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Astrodynamics 2024年第3期8卷 437-453页

作者： peng zhang Di Wu Hexi Baoyin School of Aerospace engineering Tsinghua UniversityBeijing100084China

A novel hybrid scheme for the maneuver detection and estimation of a noncooperative space target was proposed in this *** optical measurements,together with the range and range rate measurements from the ground-based radars,were used in the tracking *** many tracking scenarios,radar resources for non-cooperative targets are constrained,particularly for near-earth targets,where multiple objects can only be tracked by a single radar at a *** limitation hinders the accurate estimation of noncooperative target maneuvers,and can at times result in target *** literature has addressed this issue to some extent through various maneuvering target-tracking *** address this problem,a hybrid maneuver detection and estimation method that combines the input detection and estimation extended kalman filter and the weighted nonlinear least squares method is *** results demonstrate that the proposed method outperforms the previous method,offering more accurate and efficient estimations.

关键词： orbit determination unknown maneuver maneuver detection and estimation extended Kalman filter weighted least squares method(WLS)