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Simulation and control strategy for the variational influent of WWTP

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Journal of Environmental Sciences 2006年第1期18卷 62-68页

作者： LIU Yan-chen FAN long shi Han-chang WANG Zhi-qiang State Key Joint Laboratory of Environment Simulation and Pollution Control Department of Environmental Science and Engineering TsinghuaUniversity Beijing 100084 China

With the development of activated sludge model, the simulation software for the design and operation of wastewater treatment plant （WWTP） was produced and has been widely used. The dynamic change of the quality and flow of influent are major factors causing the unstable operation of wastewater treatment process. As a basic model, ASMI model was used for the simulation of activated sludge process, and double exponential model was selected for the simulation of secondary sedimentation tank. The influences of influent change to the aeration tank and secondary sedimentation tank were investigated, and the relationship among influent change, the quality of effluent and the level of sludge blanket in secondary sedimentation tank was established. On the basis of the simulation results, the operation of the WWTP could be adjusted under the dynamic change of the influent. Furthermore, the controlling strategy combined the feed-forward on the influent flow and the feedback on the level of sludge blanket in the secondary sedimentation tank was studied.

关键词： modeling dynamic simulation static simulation controlling strategy influent

Surrogate-assisted differential evolution using manifold learning-based sampling for highdimensional expensive constrained optimization problems

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Chinese Journal of Aeronautics 2024年第7期37卷 252-270页

作者： Teng long Nianhui YE Rong chen Renhe shi Baoshou ZHANG School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Dynamics and Control of Flight Vehicle of Ministry of Education Beijing 100081China China Academy of Launch Vehicle Technology Beijing 100076China

To address the challenges of high-dimensional constrained optimization problems with expensive simulation models,a Surrogate-Assisted Differential Evolution using Manifold Learning-based Sampling(SADE-MLS)is *** SADE-MLS,differential evolution operators are executed to generate numerous high-dimensional candidate *** alleviate the curse of dimensionality,a Manifold Learning-based Sampling(MLS)mechanism is developed to explore the high-dimensional design space *** MLS,the intrinsic dimensionality of the candidate points is determined by a maximum likelihood ***,the candidate points are mapped into a low-dimensional space using the dimensionality reduction technique,which can avoid significant information loss during dimensionality ***,Kriging surrogates are constructed in the low-dimensional space to predict the responses of the mapped candidate *** candidate points with high constrained expected improvement values are selected for global ***,the local search process assisted by radial basis function and differential evolution is performed to exploit the design space *** numerical benchmarks are tested to compare SADE-MLS with other ***,SADE-MLS is successfully applied to a solid rocket motor multidisciplinary optimization problem and a re-entry vehicle aerodynamic optimization problem,with the total impulse and lift to drag ratio being increased by 32.7%and 35.5%,*** optimization results demonstrate the practicality and effectiveness of the proposed method in real engineering practices.

关键词： Surrogate-assisted differential evolution Dimensionality reduction Solid rocket motor Re-entry vehicle Expensive constrained optimization

Linear Viscoelasticity of ABA-type Vitrimer Based on Dioxaborolane Metathesis

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Chinese Journal of Polymer Science 2024年第10期42卷 1495-1504,I0010页

作者： shi-long Wu Huan-Huan Yang Quan chen State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of ScienceChangchun130022China University of Science and Technology of China Hefei230026China

In this study,we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular *** vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the *** the average number of A monomers per end moiety m=1.1,the crosslinker can only extend the chain but not crosslink the *** m becomes 2.8 or higher,introducing a crosslinker first leads to the gelation,whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol ***,a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABAtype *** attribute this difference to the distinct relaxation mechanisms:the relaxation of the vitrimer samples is based on relatively independent exchange reactions,which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.

关键词： Polymer rheology Linear viscoelasticity ABA-type vitrimer Relaxation mechanism Kinetics and thermodynamics

On Designs of Decentralized Reputation Management for Permissioned Blockchain Networks

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1755-1773页

作者： Jinyu chen long shi Qisheng Huang Taotao Wang Daojing He School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing210094China School of Mechanical Engineering and Automation Harbin Institute of TechnologyShenzhen518055China College of Electronics and Information Engineering Shenzhen UniversityShenzhen518060China School of Computer Science and Technology Harbin Institute of TechnologyShenzhen518055China

In permissioned blockchain networks,the Proof of Authority(PoA)consensus,which uses the election of authorized nodes to validate transactions and blocks,has beenwidely advocated thanks to its high transaction throughput and fault ***,PoA suffers from the drawback of centralization dominated by a limited number of authorized nodes and the lack of anonymity due to the round-robin block proposal *** a result,traditional PoA is vulnerable to a single point of failure that compromises the security of the blockchain *** address these issues,we propose a novel decentralized reputation management mechanism for permissioned blockchain networks to enhance security,promote liveness,and mitigate centralization while retaining the same throughput as traditional *** paper aims to design an off-chain reputation evaluation and an on-chain reputation-aided ***,we evaluate the nodes’reputation in the context of the blockchain networks and make the reputation globally verifiable through smart ***,building upon traditional PoA,we propose a reputation-aided PoA(rPoA)consensus to enhance securitywithout sacrificing *** particular,rPoA can incentivize nodes to autonomously form committees based on reputation authority,which prevents block generation from being tracked through the randomness of reputation ***,we develop a reputation-aided fork-choice rule for rPoA to promote the network’s ***,experimental results show that the proposed rPoA achieves higher security performance while retaining transaction throughput compared to traditional PoA.

关键词： Blockchain reputation management PoA throughput security decentralization

Analysis and Optimization of Transient Mode Switching Behavior for Power Split Hybrid Electric Vehicle with Clutch Collaboration

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Automotive Innovation 2024年第1期7卷 150-165页

作者： Dehua shi Sheng Liu Yujie Shen Shaohua Wang Chaochun Yuan long chen Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China Jiangsu Province Engineering Research Center of Electric Drive System and Intelligent Control for Alternative Vehicles Zhenjiang 212013China

The power split hybrid electric vehicle(HEV)adopts a power coupling configuration featuring dual planetary gearsets and multiple clutches,enabling diverse operational modes through clutch engagement and *** multi-clutch configuration usually involves the collaboration of two clutches during the transient mode switching process,thereby substantially elevating control *** study focuses on power split HEVs that integrate multi-clutch mechanisms and investigates how different clutch collaboration manners impact the characteristics of transient mode *** powertrain model for the power-split HEV is established utilizing matrix-based *** the formulation of clutch torque curves and clutch collaboration models,this research systematically explores the effects of clutch engagement timing and the duration of clutch slipping state on transient mode switching *** upon this analysis,an optimization problem for control parameters pertaining to the two collaborative clutches is *** simulated annealing algorithm is employed to optimize these control *** results demonstrate that the clutch collaboration manners have a great influence on the transient mode switching *** with the pre-calibrated benchmark and the optimal solution derived by the genetic algorithm,the maximal longitudinal jerk and clutch slipping work during the transient mode switching process is reduced obviously with the optimal control parameters derived by the simulated annealing *** study provides valuable insights for the dynamic coordinated control of the power-split HEVs featuring complex clutch collaboration mechanisms.

关键词： Power split hybrid electric vehicle Transient mode switching Clutch collaboration Simulated annealing Powertrain model

Geometric phase-encoded stimuli-responsive cholesteric liquid crystals for visualizing real-time remote monitoring:humidity sensing as a proof of concept

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Light(Science & Applications) 2024年第2期13卷 283-293页

作者： shi-long Li Zhao-Yi chen Peng chen Wei Hu Chaohong Huang Sen-Sen Li Xuejia Hu Yan-Qing Lu Lu-Jian chen Department of Electronic Engineering School of Electronic Science and EngineeringXiamen University361005 XiamenChina College of Engineering and Applied Sciences Nanjing University210093 NanjingChina Fujian Key Laboratory of Ultrafast Laser Technology and Applications Xiamen University361005 XiamenChina

Liquid crystals are a vital component of modern photonics,and recent studies have demonstrated the exceptional sensing properties of stimuli-responsive cholesteric liquid ***,existing cholesteric liquid crystal-based sensors often rely on the naked eye perceptibility of structural color or the measurement of wavelength changes by spectrometric tools,which limits their practical ***,developing a platform that produces recognizable sensing signals is *** this study,we present a visual sensing platform based on geometric phase encoding of stimuli-responsive cholesteric liquid crystal polymers that generates real-time visual patterns,rather than frequency *** demonstrate this platform’s effectiveness,we used a humidity-responsive cholesteric liquid crystal polymer film encoded with a q-plate pattern,which revealed that humidity causes a shape change in the vortex beam reflected from the encoded cholesteric liquid crystal ***,we developed a prototype platform towards remote humidity monitoring benefiting from the high directionality and long-range transmission properties of laser beams carrying orbital angular *** approach provides a novel sensing platform for cholesteric liquid crystals-based sensors that offers promising practical *** ability to generate recognizable sensing signals through visual patterns offers a new level of practicality in the sensing field with stimuli-responsive cholesteric liquid *** platform might have significant implications for a broad readership and will be of interest to researchers working in the field of photonics and sensing technology.

关键词： humidity visual liquid

Adaptive Space Expansion for Fast Motion Planning

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1499-1514页

作者： Shenglei shi Jiankui chen State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning *** this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible *** ASE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary ***,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is ***,the ASE method successively does space exploring and space expan-sion until the final path has been ***,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in *** last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE *** demon-strate that the computation speed is much faster than that of the state-of-the-art *** source codes are available at https://***/shshlei/ompl.

关键词： Adaptive space expansion(ASE) hyper-ellipsoid ring informed sampling motion planning.

Cross-linked Electrospun Gel Polymer Electrolytes for Lithium-Ion Batteries

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Chinese Journal of Polymer Science 2024年第8期42卷 1021-1028页

作者： Xue Gong Qin Xiao Qing-Yin Li Wen-Cui Liang Feng chen long-Yu Li shi-Jie Ren College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Lithium-ion batteries(LIBs)benefit from an effective electrolyte system design in both terms of their safety and energy storage ***,a series of precursor membranes with high porosity were produced using electrospinning technology by mixing PVDF and triblock copolymer(PS-PEO-PS),resulting in a porous structure with good interconnections,which facilitates the absorbency of a large amount of electrolyte and further increases the ionic conductivity of gel polymer electrolytes(GPEs).It has been demonstrated that post-cross-linking of the precursor membranes increa ses the rigidity of the nanofibers,which allows the polymer film to be dimensionally sta ble up to 260℃while maintaining superior electrochemical *** obtained cross-linked GPEs(CGPEs)showed high ionic conductivity up to 4.53×10^(-3)S·cm^(-1).With the CGPE-25,the assembled Li/LiFeP04 half cells exhibited good rate capability and maintained a capacity of 99.4%and a coulombic efficiency of99.3%at 0.1 *** results suggest that the combination of electrospinning technique and post-cross-linking is an effective method to construct polymer electrolytes with high thermal stability and steadily decent electrochemical performance,particularly useful for Lithium-ion battery applications that require high-temperature usage.

关键词： Electrospinning Cross-linked Gel polymer electrolytes Lithium-ion batteries

Preparation of Environmentally Friendly Urea-Hexanediamine-Glyoxal(HUG)Resin Wood Adhesive

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Journal of Renewable Materials 2024年第2期12卷 235-244页

作者： Qianyu Zhang shi chen long Cao Hong Lei Antonio Pizzi Xuedong Xi Guanben Du Yunnan Key Laboratory of Wood Adhesives and Glue Products College of Material Science and EngineeringSouthwest Forestry UniversityKunming650224China International Joint Research Center for Biomass Materials Southwest Forestry UniversityKunming650224China College of Chemical and Materials Engineering Zhejiang A&F UniversityHangzhou311300China LERMAB University of LorraineEpinal88000France

Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood ***,urea-glyoxal(UG)resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of *** results in a poorer bonding performance and water resistance of UG resins.A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization,and then to condense these with glyoxal to obtain a novel UG ***,in this present work,the urea was reacted with hexamethylene diamine to form a polyurea named HU,and then this was used to react it with different amounts of glyoxal to synthesize hexamethylenediamine-urea-glyoxal(HUG)polycondensation resins,and to use this for bonding *** results show that the glyoxal can well react with HU polyuria via addition and schiff base reaction,and also the HUG resin exhibits excellent bonding strength and water *** shear strength of the plywood bonded with this HUG at 160°C hot press temperature as high as 1.93 MPa,2.16 MPa and 1.61 MPa,respectively,which meets the requirement of the China national standard GB/T 9846-2015(≥0.7 MPa),and can be a good choice as a wood adhesive for industrial application.

关键词： Urea-glyoxal resin hexamethylene diamine wood adhesives water resistance