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Multi-surrogate framework with an adaptive selection mechanism for production optimization

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Petroleum Science 2024年第1期21卷 366-383页

作者： Jia-Lin Wang Li-Ming zhang Kai zhang Jian Wang Jian-Ping Zhou Wen-Feng Peng Fa-Liang Yin Chao Zhong Xia Yan Pi-Yang Liu hua-qing zhang Yong-Fei Yang Hai Sun School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580ShandongChina qingdao University of Technology Qingdao266580ShandongChina College of Science China University of PetroleumQingdao266580ShandongChina Zepu Oil and Gas Development Department PetroChina Tarim Oilfield CompanyKorla841000XinjiangChina Hainan Branch of CNOOC Ltd Haikou70311HainanChina

Data-driven surrogate models that assist with efficient evolutionary algorithms to find the optimal development scheme have been widely used to solve reservoir production optimization problems.However,existing research suggests that the effectiveness of a surrogate model can vary depending on the complexity of the design problem.A surrogate model that has demonstrated success in one scenario may not perform as well in others.In the absence of prior knowledge,finding a promising surrogate model that performs well for an unknown reservoir is challenging.Moreover,the optimization process often relies on a single evolutionary algorithm,which can yield varying results across different cases.To address these limitations,this paper introduces a novel approach called the multi-surrogate framework with an adaptive selection mechanism(MSFASM)to tackle production optimization problems.MSFASM consists of two stages.In the first stage,a reduced-dimensional broad learning system(BLS)is used to adaptively select the evolutionary algorithm with the best performance during the current optimization period.In the second stage,the multi-objective algorithm,non-dominated sorting genetic algorithm II(NSGA-II),is used as an optimizer to find a set of Pareto solutions with good performance on multiple surrogate models.A novel optimal point criterion is utilized in this stage to select the Pareto solutions,thereby obtaining the desired development schemes without increasing the computational load of the numerical simulator.The two stages are combined using sequential transfer learning.From the two most important perspectives of an evolutionary algorithm and a surrogate model,the proposed method improves adaptability to optimization problems of various reservoir types.To verify the effectiveness of the proposed method,four 100-dimensional benchmark functions and two reservoir models are tested,and the results are compared with those obtained by six other surrogate-model-based methods.The results demonstrate that our approach can obtain th

关键词： Production optimization Multi-surrogate models Multi-evolutionary algorithms Dimension reduction Broad learning system

Construction of Safety and Non-flammable Polyimide Separator Containing Carboxyl Groups for Advanced Fast Charing Lithium-ion Batteries

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Chinese Journal of Polymer Science 2022年第4期40卷 345-354页

作者： Ji-Ping Gu Kai-Yuan zhang Xiu-Ting Li Jie Dong qing-hua zhang Xin Zhao State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China

With the wide applications of lithium-ion batteries(LIBs)in electronic devices and electric vehicles,it is of great importance to improve their safety and electrochemical performance.Herein,soluble polyimides(PI)containing carboxyl groups(―COOH)were synthesized by a simple one-step method and PI separators with sponge-like,interpenetrating porous structures were prepared via non-solvent induced phase separation(NIPS).The obtained PI separators exhibited excellent thermal stability and fire-resistance properties,with the electrolyte uptake of 344%and good dimensional integrity in air at 200℃.The results showed that the lithium-ion transference number of the obtained PI separator could reach 0.48,which was much higher than that of the Celgard-2400 separator(0.38).The Li/LiFePO_(4) half-cell with the PI separator showed excellent cycle capability and high-rate performance with a high capacity of 121.80 mA·h·g^(-1) at 5 C,which was better than that of the cell with the Celgard-2400 separator(54.3 mA·h·g^(-1)),demonstrating the promising applications of this PI separators in LIBs.

关键词： Polyimide Separator Carboxyl groups Non-solvent induced phase separation Li transference number

Highly Hydrolysis-Resistant Polyimide Fibers Prepared by Thermal Crosslinking with Inherent Carboxyl Groups

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Chinese Journal of Polymer Science 2024年第2期42卷 247-255,I0010页

作者： Can-Can zhang Jun-Long Yang Ya-Jiang huang Guang-Xian Li College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering of ChinaSichuan UniversityChengdu610065China

Easy hydrolysis in alkaline environments limits the use of polyimide fibers in environmental protection. The hydrolysis resistance levels of polyimide fibers can be improved by crosslinking of the macromolecular chains. In this work, crosslinked polyimide fibers(CPI fibers) were produced by intrinsic carboxyl decarboxylation for the first time. The thermal stability of the polyimide fibers containing the intrinsic carboxyl groups(PIC fibers) was studied, and the temperature of the decarboxylation-crosslinking reaction was determined to be 450 ℃. The PIC fibers were hotdrawn to initiate thermal crosslinking of the carboxyl groups and molecular chain orientation at high temperature. The CPI fibers had high tensile strengths(0.72-1.46 GPa) and compressive strengths(401-604 MPa). The oriented macromolecules and chemically crosslinked structure improved the tightness of the molecular chains and endowed the CPI fibers with excellent hydrolytic resistance. The CPI-50 fiber did not dissolve in a 0.5 wt% NaOH solution during heating at 90 ℃ for 10 h, and the tensile strength retention reached 87% when treated in 0.5 wt% NaOH solutions at 90 ℃ for 1 h, providing a guarantee for its application in alkaline corrosive environments.

关键词： Polyimide Carboxyl group Crosslinking Hydrolysis-resistance

Dry-spun Polyimide Fibers with Excellent Thermal Stability,Intrinsic Flame Retardancy and Ultralow Smoke Release

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Chinese Journal of Polymer Science 2022年第11期40卷 1422-1431页

作者： Han Dong Yu-Ping Wang Xiu-Ting Li Xin Zhao Jie Dong qing-hua zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China Jiangsu New Vision Advanced Functional Fiber Innovation Center Co. Ltd.Suzhou215000China

Polymer fiber with an ultrahigh thermal stability,superior flame retardancy and low smoke release during combustion is urgently needed and a crucial challenge for developing advanced fireproof textiles.In this study,a series of high-performance polyimide fibers are synthesized by copolymerizing 4,4'-diaminodiphenylmethane(MDA)into the pyromellitic dianhydride-p-phenylenediamine(PMDA-PDA)backbone for synergistically solving the technical challenge of poor fiber processing ability of these polyimides with a high inherent molecular rigidity.The glass transition temperature(Tg)of resultant fibers with the PDA molar ratio over 50 mol%reaches above 420℃ and their 10 wt%weight loss temperature(T10%)is within 543-633℃.For the typical fiber containing 80 mol%of PDA,the limiting oxygen index(LOI)reaches 39%and exhibits a rapid self-extinguishing performance after deviating from the flame.Meanwhile,this fiber exhibits the minimum heat release rate of 14.1 kW/m^(2) in a long ignition time of 813 s during combustion,revealing its better flame retardancy than the well-known Nomex fiber with a heat release rate of 140.6 kW/m^(2) during the 120 s ignition.Meanwhile,the total smoke production of this polyimide fiber is only 1/9 of the Nomex fiber.Accordingly,the excellent flame retardancy of polyimide fibers indicating them more attractive as the fireproof materials in the field of emergency protection.

关键词： Polyimide fiber Copolymerization Thermal stability Flame retardancy Smoke release

Preparation of High-performance Polyimide Fibers with Wholly Rigid Structures Containing Benzobisoxazole Moieties

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Chinese Journal of Polymer Science 2022年第3期40卷 280-289,I0007页

作者： Yu-Ting Fang Feng Gan Jie Dong Xin Zhao Xiu-Ting Li qing-hua zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai 201620China School of Textile Materials and Engineering Wuyi UniversityJiangmen 529020China

In this work, a fully rigid coplanar symmetric heterocyclic unit was introduced into the rigid polyimide macromolecular backbone structure to prepare high-performance polyimide fibers. The novel co-polyimide(co-PI) fibers based on 3,3',4,4'-biphenyltetracarboxylic anhydride(BPDA), p-phenylenediamine(PDA) and 2,6-(4,4'-diaminodiphenyl) benzo[1,2-d:5,4-d'] bisoxazole(PBOA) were fabricated via a twostep wet-spinning method. The effects of benzobisoxazole moiety on spinnability, aggregation structure, and mechanical properties of fibers were systematically discussed. The detailed structural analysis revealed that the well-defined aggregation structures of co-PI fibers were obtained from initial amorphous structure when post hot-drawing temperature was higher than 460 ℃ under proper drawing ratio, and the incorporation PBOA into BPDA-PDA structures produced more compact structural co-PI fiber than homo BPDA-PDA fiber. The BPDA-PDA/PBOA co-PI fibers exhibited optimum tensile strength and modulus of 2.65 and 103 GPa, which increased by 182% and 84% compared to the homo BPDA-PDA fiber, respectively.

关键词： Polyimide fiber Benzobisoxazole Co-polymerization Microstructure Mechanical properties

In-situ constructed Cu/CuNC interfaces for low-overpotential reduction of CO2 to ethanol

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National Science Review 2023年第4期10卷 105-113页

作者： Yan Yang Jiaju Fu Yixin Ouyang Tang Tang Yun zhang Li-Rong Zheng qing-hua zhang Xiao-Zhi Liu Jinlan Wang Jin-Song Hu Beijing National Laboratory for Molecular Sciences (BNLMS) CAS Key Laboratory of Molecular Nanostructure and Nanotechnology Institute of Chemistry Chinese Academy of Sciences Research Institute Zhejiang Tiandi Environmental Protection Technology Co.Ltd University of Chinese Academy of Sciences School of Physics Southeast University Institute for Advanced Study Shenzhen University Institute of High Energy Physics Chinese Academy of Sciences Institute of Physics Chinese Academy of Sciences

Electrochemical CO2reduction(ECR) to high-value multi-carbon(C2+) products is critical to sustainable energy conversion, yet the high energy barrier of C-C coupling causes catalysts to suffer high overpotential and low selectivity toward specific liquid C2+products. Here, the electronically asymmetric Cu-Cu/Cu-N-C(Cu/Cu NC) interface site is found, by theoretical calculations, to enhance the adsorption of*CO intermediates and decrease the reaction barrier of C-C coupling in ECR, enabling efficient C-C coupling at low overpotential. The catalyst consisting of high-density Cu/Cu NC interface sites(noted as ER-Cu/CuNC) is then accordingly designed and constructed in situ on the high-loading Cu-N-C single atomic catalysts. Systematical experiments corroborate the theoretical prediction that the ER-Cu/Cu NC boosts electrocatalytic CO2-to-ethanol conversion with a Faradaic efficiency toward C2+of 60.3%(FEethanol of 55%) at a low overpotential of-0.35 V. These findings provide new insights and an atractive approach to creating electronically asymmetric dual sites for efficient conversion of CO2to C2+products.

关键词： Cu/CuNC interface low overpotential CO2 reduction ethanol electrocatalysis

A fractional-order multifunctional n-step honeycomb RLC circuit network

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Frontiers of Information Technology & Electronic Engineering 2017年第8期18卷 1186-1196页

作者： Ling ZHOU Zhi-zhong TAN qing-hua zhang Department of Physics Nantong University Nantong 226019 China Department of Mathematics Nantong University Nantong 226019 China

研究了一类多功能n阶蜂巢型电阻网络模型,该问题一直未被解决。通过调节电路参数,该网络模型可以转化为含有多种功能的数个不同网络模型,例如一个规则的梯形网络、一个n阶三角形网络,等。我们导出了电阻网络的2个新的等效电阻公式,同时... 详细信息

研究了一类多功能n阶蜂巢型电阻网络模型,该问题一直未被解决。通过调节电路参数,该网络模型可以转化为含有多种功能的数个不同网络模型,例如一个规则的梯形网络、一个n阶三角形网络,等。我们导出了电阻网络的2个新的等效电阻公式,同时导出了LC网络的等效复阻抗公式,它们都属于分数阶范畴。首先,将一个复杂网络简化为一个简单的等效模型;其次,应用基尔霍夫定律,建立一个分式差分方程模型;再次,采用等效变换方法,给出非线性差分方程的通解。在实际应用中,获得了数个有趣的特殊结论。特别地,讨论分析了一个n阶LC复阻抗网络,发现了许多新的等效复阻抗特性。

关键词：蜂巢型网络等效变换分数阶差分方程复阻抗特性

Impacts of water surface area of watershed on design flood

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Water Science and Engineering 2014年第1期7卷 41-48页

作者： qing-hua zhang Yan-fang DIAO Jie DONG College of Water Conservancy and Civil Engineering Shandong Agricultural University State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University

In order to analyze the impact of the water surface area of a watershed on the design flood, the watershed was classified into a land watershed and a water surface watershed for flood flow calculation at the same time interval. Then, the design flood of the whole watershed was obtained by adding the two flood flows together. Using this method, we calculated design floods with different water surface areas of three reservoirs and analyzed the impact of water surface area on the flood volume and peak flow. The results indicate that larger water surface areas lead to greater impacts on the flood volume and peak flow. For the same watershed area, the impact of water surface area on the flood volume and peak flow is positively proportional to the flood frequency, i.e., the higher the frequency, the greater the impact becomes.

关键词： watershed water surface area design flood, flood frequency flood volume peak Jlow

Experimental study on discharge coefficient of a gear-shaped weir

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Water Science and Engineering 2018年第3期11卷 258-264页

作者： Jing zhang Qian Chang qing-hua zhang Shu-ning Li College of Water Conservancy and Civil Engineering Shandong Agricultural University River Management Bureau Huaihe River Commission of the Ministry of Water Resources

This study focused on hydraulic characteristics around a gear-shaped weir in a straight channel. Systematic experiments were carried out for weirs with two different gear heights and eight groups of geometrical parameters. The impacts of various geometrical parameters of gear-shaped weirs on the discharge capacity were investigated. The following conclusions are drawn from the experimental study:(1) The discharge coefficient(m_c) was influenced by the size of the gear: at a constant discharge, the weir with larger values of a/b(a is the width of the gear, and b is the width between the two neighboring gears) and a/c(c is the height of the gear) had a smaller value of m_c. The discharge capacity of the gear-shaped weir was influenced by the water depth in the weir.(2) For type C1 with a gear height of 0.01 m, when the discharge was less than 60m^3/h and H_1=P 1.0, m_c slowly decreased with the increases of the discharge and H_1=P for a=b 1.0 and a=c 1.0, and slowly increased with the discharge and H_1=P for a=b > 1.0 and a=c > 1.0.(3) A formula of m_cfor gear-shaped weirs was established based on the principle of weir flow, with consideration of the water depth in the weir, the weir height and width, and the height of the gear.

关键词： Experimental study Discharge coefficient Discharge capacity Gear-shaped weir Geometrical parameter