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Physics-informed neural network-based petroleum reservoir simulation with sparse data using domain decomposition

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Petroleum Science 2023年第6期20卷 3450-3460页

作者： Jiang-Xia Han Liang Xue Yun-Sheng Wei Ya-Dong Qi jun-lei wang Yue-Tian Liu Yu-Qi Zhang National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Department of Oil-Gas Field Development Engineering College of Petroleum EngineeringChina University of PetroleumBeijing102249China PetroChina Research Institute of Petroleum Exploration&Development Beijing100083China Lushang Oilfield Operation Area Jidong Oilfield CompanyPetroChinaTangshan063000HebeiChina

Recent advances in deep learning have expanded new possibilities for fluid flow simulation in petroleum reservoirs.However,the predominant approach in existing research is to train neural networks using high-fidelity numerical simulation data.This presents a significant challenge because the sole source of authentic wellbore production data for training is sparse.In response to this challenge,this work introduces a novel architecture called physics-informed neural network based on domain decomposition(PINN-DD),aiming to effectively utilize the sparse production data of wells for reservoir simulation with large-scale systems.To harness the capabilities of physics-informed neural networks(PINNs)in handling small-scale spatial-temporal domain while addressing the challenges of large-scale systems with sparse labeled data,the computational domain is divided into two distinct sub-domains:the well-containing and the well-free sub-domain.Moreover,the two sub-domains and the interface are rigorously constrained by the governing equations,data matching,and boundary conditions.The accuracy of the proposed method is evaluated on two problems,and its performance is compared against state-of-the-art PINNs through numerical analysis as a benchmark.The results demonstrate the superiority of PINN-DD in handling large-scale reservoir simulation with limited data and show its potential to outperform conventional PINNs in such scenarios.

关键词： Physical-informed neural networks Fluid flow simulation Sparse data Domain decomposition

A GMM approach in coupling internal data and external summary information with heterogeneous data populations

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Science China Mathematics 2024年第5期67卷 1115-1132页

作者： jun Shao Jinyi wang lei wang Key Laboratory of Advanced Theory and Application in Statistics and Data Science(East China Normal University) Ministry of EducationShanghai 200062China School of Statistics East China Normal UniversityShanghai 200062China Department of Statistics University of Wisconsin-MadisonWI 53706USA School of Statistics and Data Science KLMDASRLEBPS and LPMCNankai UniversityTianjin 300071China

Because of advances in data collection and storage,statistical analysis in modern scientific research and practice now has opportunities to utilize external information such as summary statistics from similar studies.A likelihood approach based on a parametric model assumption has been developed in the literature to utilize external summary information when the populations for external and main internal data are assumed to be the same.In this article,we instead consider the generalized estimation equation(GEE)approach for statistical inference,which is semiparametric or nonparametric,and show how to utilize external summary information even when internal and external data populations are not the same.Our approach is coupling the internal data and external summary information to form additional estimation equations and then applying the generalized method of moments(GMM).We show that the proposed GMM estimator is asymptotically normal and,under some conditions,is more efficient than the GEE estimator without using external summary information.Estimators of the asymptotic covariance matrix of the GMM estimators are also proposed.Simulation results are obtained to confirm our theory and quantify the improvements by utilizing external data.An example is also included for illustration.

关键词： adjustment for heterogeneity constraint data integration generalized method of moments summarystatistic

The response and anti-stress mechanisms of nitrifying sludge under long-term exposure to Cd Se quantum dots

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Journal of Environmental Sciences 2024年第1期135卷 174-184页

作者： Linkai Guo lei Yang Yongxiang Ren Shen Cui Xiaotong Li Jia wang jun Lan Haoqi Lu Yuchao wang Shaanxi Key Laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key Lab of Northwest Water Resource Environment and EcologyMinistry of EducationXi’an University of Architecture and TechnologyXi’an 710055China

The wide application of CdSe quantum dots(QDs)increases its stress risk to sewage treatment systems.This study evaluated the response of nitrification performance,floc characteristics and microbial community of nitrifying sludge under long-term exposure to CdSe QDs.Results showed CdSe QDs(≥1 mg/L)would decrease the activity of ammonia monooxygenase(AMO).Under the stress of 30 mg/L CdSe QDs,the activity of AMO was reduced by 66%,while the activities of hydroxylamine oxidase and nitrite oxidoreductase were enhanced by 19.1%and 26%,respectively.Thus,the final nitrification effects were not adversely affected,and the production rates of NO_(2)^(-)-N and NO_(3)^(-)-N were accelerated.Additionally,CdSe QDs improved biomass concentration in sludge and maintained the stability of sludge settleability.High throughput sequencing analysis showed that CdSe QDs evidently reduced the abundance and diversity of microbial community in nitrifying sludge.The abundances of amino acid metabolism and lipid metabolism were enriched.Moreover,CdSe QDs decreased the fluorescence intensity of tryptophan-like protein from 2,326 to 1,179 a.***.in loosely bound extracellular polymeric substances(EPSs)and from 3,792 to 3,117 a.***.in tightly bound EPSs.To relieve CdSe QD stress,the polysaccharide content increased from0.31 to 0.61 mg/g MLSS and intracellular antioxidant defense was activated.With CdSe QD level increasing to 30 mg/L,the total antioxygenic capacity and the activities of catalase were enhanced up to 411%and 143.2%,respectively.Thereby,CdSe QDs had little adverse effects on cell membrane integrity,microbial metabolism and the abundance of Nitrospirae.

关键词： Quantum dots Activated sludge Extracellular polymeric substances Microbial community Antioxidant effect

Effect of electrical parameters and slag system on macrostructure of electroslag ingot

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China Foundry 2024年第1期21卷 44-50页

作者： Bing-jie wang Yu wang Meng-jun wang lei Zhao Li-zhong Chang Xiao-fang Shi School of Metallurgy engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina

To investigate the influence of electric parameters and slag system on the solidification quality of electroslag ingot during electroslag remelting,different power supply modes,current strengths and remelting slag systems were used to conduct electroslag remelting experiments on 304L austenitic stainless steel,and the macrostructure of electroslag ingots was analyzed.The results indicate that the depth of the metal pool decreases with the reduction of remelting frequency in the low frequency power supply mode.The effects of different power supply modes,such as low-frequency,direct current straight polarity(DCSP),and direct current reverse polarity(DCRP),on reducing the depth of the metal pool increase in that order.By reducing the remelting current strength in the same power supply mode,the depth of metal pool is reduced.When compared to the binary slag system of 70%CaF2+30%Al2O3,the ternary slag system of 60%CaF2+20%Al2O3+20%CaO is more effective in reducing the depth of the metal pool during remelting.Utilizing the 60%CaF2+20%Al2O3+20%CaO ternary slag system results in a shallower and flatter metal pool,with columnar crystal growth occurring closer to the axial crystal.This effect is observed for both low frequency and direct current(DC)power supply modes.

关键词： electroslag remelting frequency slag system solidification quality

Energy Harvesting in the Wake of An Inverted C-Shaped Bluff Body

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China Ocean Engineering 2024年第1期38卷 68-80页

作者： wang jun-lei LI Shen-fang Md.Mahbub ALAM ZHU Hong-jun HU Guo-biao School of Mechanical and Power Engineering Zhengzhou UniversityZhengzhou 450000China Center for Turbulence Control Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China Internet of Things Thrust The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511400China

This paper proposes a novel wake-induced vibration(WIV)-based energy harvesting system consisting of two bluff bodies.An inverted C-shaped bluff body is stationary installed at the upstream position to generate an interference wake street,and a cylinder bluff body equipped with a transducer is elastically suspended at the downstream position to harness WIV energy.The hydrodynamics and energy harvesting(EH)performance of the proposed system are investigated via experimental studies.The reduced velocity(U*)ranging from 2 to 14(the corresponding Reynolds number ranging from 15100 to 106200)is considered in the present study.It is found that the wake generated by the inverted C-shaped bluff body significantly affects the EH performance.Enlarging the opening angle(α)of the C-shaped bluff body increases the vibration amplitude of the downstream cylinder,thereby increasing the harvested power.When the spacing(L)between two bluff bodies is two times the cylinder diameter(D),the wake-induced vibration(WIV)mode is observed,while the combined WIV and wake galloping(WG)mode occurs whenαis 150°,and L equals 3D or 4D.The average drag coefficient becomes negative when L is 2D,3D,or 4D.By carefully configuring a C-shaped bluff body,the wake generated by it can bring an augmenting effect on the vibration of the downstream EH cylinder.For example,the RMS power output of the proposed EH system reaches a maximum of 0.31 W at U*=8 and L=4D,which is 300%greater than that of its traditional counterpart.Furthermore,after a number of case stud-ies,it is identified that the proposed EH system can achieve the best performance whenαis 150°and L=2D.

关键词： wake-induced vibration vortex-induced vibration galloping energy harvesting bluff body

2D–3D dual carbon layer confined ultrasmall VN nanoparticles for improving lithium-ion storage in hybrid capacitors

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Rare Metals 2024年第1期43卷 65-75页

作者： Zhao-Wei Hu Hui-Fang Li Peng wang Wan-Li wang lei Yang Xiao-jun wang Zhi-Ming Liu College of Electromechanical Engineering Shandong Engineering Laboratory for Preparation and Application of High-Performance Carbon-MaterialsQingdao University of Science&TechnologyQingdao 266061China Research Center for Intelligent and Wearable Technology College of Textiles and ClothingQingdao UniversityQingdao 266071China

Lithium-ion capacitors(LICs) of achieving high power and energy density have garnered significant attention. However, the kinetics unbalance between anode and cathode can impede the application of LICs. Vanadium nitride(VN) with a high theoretical specific capacity(~ 1200 m Ah·g^(-1)) is a better pseudocapacitive anode to match the response of cathode in LICs. However, the insertion/extraction of Li-ions in VN's operation results in significant volume expansion. Herein, the VN/N-r GO-5composite that three-dimentional(3D) dicyandiamidederived-carbon(DDC) tightly wrapped VN quantum dots(VN QDTs) on two-dimentional(2D) reduced graphene oxid(r GO) was prepared by a facile strategy. The VN QDTs can reduce ion diffusion length and improve charge transfer kinetics. The 2D r GO as a template provides support for nanoparticle dispersion and improves electrical conductivity. The 3D DDC tightly encapsulated with VN QDTs mitigates agglomeration of VN particles as well as volume expansion. Correspondingly, the LICs with VN/Nr GO-5 composite as anode and activated carbon(AC) as cathode were fabricated, which exhibits a high energy density and power density. Such strategy provides a perspective for improving the electrochemical properties of LIC anode materials by suppressing volume expansion and enhancing conductivity.

关键词： Vanadium nitride(VN)quantum dots Reduced graphene oxide(rGO)nanosheets Dicyandiamide-derived-carbon 2D–3D dual carbon layer Lithium-ion capacitors

Experimental study and simulation on the creep characteristics of machineharvested seed cotton

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 241-250页

作者： Ximei Wei Hongwen Zhang jun wang Shufeng Li lei wang Xintian Du College of Mechanical and Electrical Engineering Shihezi UniversityShihezi 832003XinjiangChina Key Laboratory of Northwest Agricultural Equipment Ministry of AgricultureShihezi 832003XinjiangChina

In view of the unclear understanding of the basic scientific problems such as the rheological mechanism of seed cotton,especially the lack of research on the creep characteristics of seed cotton,the machine-harvested seed cotton in the Xinjiang region was taken as the research object to find out the compression creep characteristics.The universal material testing machine was used to carry out a one-factor creep test,taking moisture content,feed quality,compression times,and trash content as test factors and instantaneous elastic modulus,hysteretic elastic modulus,viscosity coefficient,and delay time as test indicators.The ANOVA and correlation were analyzed by SPSS,and the creep process of the seed cotton was simulated by ADAMS.Results show that moisture content significantly affects the instantaneous elastic modulus,hysteretic elastic modulus,and viscosity coefficient(p<0.01).In addition,each value of which decreases with the increase in moisture content.Feed quality significantly affects the hysteretic elastic modulus and viscosity coefficient(p<0.05).Moreover,the hysteretic elastic modulus and viscosity coefficient increase with the increase in feed quality.The compression times significantly influence the instantaneous elastic modulus,hysteretic elastic modulus,and viscosity coefficient(p<0.01),each value of which increases with the increase of compression times.Furthermore,the trash content significantly influenced the hysteretic elastic modulus and viscosity coefficient(p<0.05).The absolute error between the simulated and experimental values ek is within−0.011-0.030 mm,and the relative errorφk is less than 7%.The experimental results can provide theoretical and data support for the study of rheological characteristics of machine-harvested seed cotton,the design of seed cotton packing devices,and the molding quality of cotton bale(mold).

关键词： creep characteristics machine-harvested seed cotton analysis of ANOVA one-factor tests ADAMS

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

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Bio-Design and Manufacturing 2024年第1期7卷 1-13页

作者： Huaizhi Zong junhui Zhang lei Jiang Kun Zhang jun Shen Zhenyu Lu Ke wang Yanli wang Bing Xu The State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China Unmanned Vehicle Research and Development Center China North Vehicle Research InstituteBeijing 100072China School of Mechatronic Engineering Nanchang UniversityNanchang 330031China Auclean High-Tech Ltd. Wuxi 214108China

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

关键词： Additive manufacturing Bionic lightweight design Limb leg unit Quadruped robot Trajectory tracking

Bifunctional core–shell co-catalyst for boosting photocatalytic CO_(2) reduction to CH_(4)

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Nano Research 2024年第3期17卷 1259-1266页

作者： Fangxu Dai Mingming Zhang Jishu Han Zhenjiang Li Shouhua Feng jun Xing lei wang Key Laboratory of Eco-chemical Engineering Ministry of EducationCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Materials Science and Engineering Qingdao University of Science and TechnologyQingdao 266042China College of Environment and Safety Engineering Qingdao University of Science and TechnologyShandong Engineering Research Center for Marine Environment Corrosion and Safety ProtectionQingdao 266042China

Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant challenge.Here,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and*CHO.The photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction reaction.This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.

关键词： bifunctional co-catalyst core–shell photocatalytic CO_(2)reduction