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Optimization for ASP flooding based on adaptive rationalized Haar function approximation

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Chinese journal of Chemical Engineering 2018年第8期26卷 1758-1765页

作者： yulei Ge Shurong Li Xiaodong Zhang College of Information and Control Engineering China University of Petroleum (East China) Automation School Beijing University of Posts and Telecommunications

This paper presents an adaptive rationalized Haar function approximation method to obtain the optimal injection strategy for alkali-surfactant-polymer(ASP) flooding. In this process, the non-uniform control vector parameterization is introduced to convert original problem into a multistage optimization problem, in which a new normalized time variable is adopted on the combination of the subinterval length. Then the rationalized Haar function approximation method, in which an auxiliary function is introduced to dispose path constraints, is used to transform the multistage problem into a nonlinear programming. Furthermore, an adaptive strategy proposed on the basis of errors is adopted to regulate the order of Haar function vectors. Finally, the nonlinear programming for ASP flooding is solved by sequential quadratic programming. To illustrate the performance of proposed method,the experimental comparison method and control vector parameterization(CVP) method are introduced to optimize the original problem directly. By contrastive analysis of results, the accuracy and efficiency of proposed method are confirmed.

关键词： Alkali-surfactant-polymer flooding Optimization Enhanced oil recovery Mathematical modeling Rationalized Haar function approximation Adaptive strategy

Pattern recognition of messily grown nanowire morphologies applying multi-layer connected self-organized feature maps

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journal of Materials Science & Technology 2019年第5期35卷 946-956页

作者： Qing Liu Hejun Li yulei Zhang Zhigang Zhao State Key Laboratory of Solidification Processing Carbon/Carbon Composites Technology Research Center Northwestern Polytechnical University

Multi-layer connected self-organizing feature maps(SOFMs) and the associated learning procedure were proposed to achieve efficient recognition and clustering of messily grown nanowire morphologies. The network is made up by several paratactic 2-D SOFMs with inter-layer connections. By means of Monte Carlo simulations, virtual morphologies were generated to be the training samples. With the unsupervised inner-layer and inter-layer learning, the neural network can cluster different morphologies of messily grown nanowires and build connections between the morphological microstructure and geometrical features of nanowires within. Then, the as-proposed networks were applied on recognitions and quantitative estimations of the experimental morphologies. Results show that the as-trained SOFMs are able to cluster the morphologies and recognize the average length and quantity of the messily grown nanowires within. The inter-layer connections between winning neurons on each competitive layer have significant influence on the relations between the microstructure of the morphology and physical parameters of the nanowires within.

关键词： Artificial neural networks Self-organizing feature maps Monte Carlo simulation Pattern recognition Messily grown nanowire morphologies

Microscopic Mechanism of Large Fluctuation in Odd-Even Differences in Moments of Inertia for Actinide Nuclei

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Communications in Theoretical Physics 2005年第2期43卷 287-294页

作者： yulei GONGLun-Xun LIUShu-Xin ZENGjin-Yan DepartmentofPhysics PekingUniversityBeijing100871China／／DepartmentofPhysicsGuizhouNormalUniversityGuiyang550001China DepartmentofPhysics PekingUniversityBeijing100871China

The experimental large fluctuation in odd-even differences in moments ofinertia of deformed actinide nuclei is investigated using the particle-number conserving (PNC)method for treating the cranked shell model with monopole and quadrupole pairing interactions. PNCcalculations show that the large odd-even difference in moments of inertia mainly comes from theinterference contributions j(μv) from particles in high j intruder orbitals μ and v quite near theFermi surface, which have no counterpart in the BCS formalism. The effective monopole andquadrupole pairing interaction strengths are determined to fit the experimental odd-even differencesin binding energies and bandhead moments of inertia. The experimental results for the variation ofmoments of inertia with rotational frequency ω are reproduced well by the PNC calculation. Thenearly identical experimental moments of inertia between ~(236)U(gsb) and ~(238)U(gsb) at lowfrequencies hω ≤ 0.20 MeV are also reproduced quite well.

关键词： odd-even differences in moments of inertia cranked shell model particle-number conserving treatment

Oxidation and Mechanical Properties of SiC/SiC-MoSi_2-ZrB_2 Coating for Carbon/Carbon Composites

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journal of Materials Science & Technology 2014年第2期30卷 123-127页

作者： Xiyuan Yao Hejun Li yulei Zhang Yongjie Wang State Key Laboratory of Solidification Processing Northwestern Polytechnical University

To improve oxidation resistance of carbon/carbon （C/C） composites, a SiC/SiC-MoSi2-ZrB2 double-layer ceramic coating was prepared on C/C composites by two-step pack cementation. The phase compositions and microstructures of as-prepared multilayer coating were characterized by X-ray diffraction and scanning electron microscopy. The oxidation resistance at 1773 K and the effect of thermal shock between 1773 K and room temperature on mechanical performance of coated specimens were investigated. The results show that the SiC/SiC-MoSi2-ZrB2 coating exhibits dense structure and is composed of SiC, Si, MoSi2 and ZrB2. It can protect C/C composites from oxidation at 1773 K for more than 510 h with weight loss of 0.5%. The excellent anti-oxidation performance of the coating is due to the formation of SiO2-ZrSiO4 complex glassy film. The coating can also endure the thermal shocks between 1773 K and room temperature for 20 times with residual flexural strength of 86.1%.

关键词： Carbon/carbon composites Ceramic coating Oxidation resistance Thermal cycle Mechanical properties

Refined modeling and experimental verification of a torque motor for an electro-hydraulic servo valve

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Chinese journal of Aeronautics 2023年第6期36卷 302-317页

作者： Zhichuang CHEN Shenghong GE yulei jIANG Wenhao CHENG Yuchuan ZHU National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Engineering Institute of Aircraft SystemsNanjing 210061China AVIC Nanjing Servo Control System Co. LtdNanjing 210032China

The Permanent Magnet Torque Motor(PMTM)is the key electro-mechanical conversion device in an Electro-Hydraulic Servo Valve(EHSV).In this work,a refined model of a PMTM is developed,considering the non-working air-gaps between the upper or lower yoke and the armature,the fringing effect at the limiting holes,and the nonlinear permeability of soft magnetic *** on the refined model,the influences of various factors on the calculation accuracy of the magnetic flux at the pole surfaces of the armature and the output torque are *** verifying the validity of the refined model,a Finite Element Analysis(FEA)of the PMTM is conducted,and a test platform is *** with existing models,the refined model can better reveal the intrinsic mechanism of the PMTM,and its calculations are more consistent with the FEA *** experimental results of the armature deflection displacement show that the refined model can accurately describe the output characteristics of the PMTM.

关键词： Calculation accuracy Electro-hydraulic servo valve Experimental verification Finite element analysis Refined model Torque motor

An ubiquitin-like protein SDE2 negatively affects sucrose-induced anthocyanin biosynthesis in Arabidopsis

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Science Bulletin 2017年第23期62卷 1585-1592页

作者： Ye Xie yulei Zhao Huijuan Tan Qin Chen jirong Huang National Key Laboratory of Plant Molecular Genetics CAS Center for Excellence in Molecular Plant Sciences Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200032 China University of the Chinese Academy of Sciences Beijing 100049 China School of Life Sciences Shanghai University Shanghai 200444 China College of Life and Environmental Sciences Shanghai Normal University Shanghai 200234 China

Anthocyanin biosynthesis is regulated by a conserved transcriptional MBW complex composed of MYB,b HLH and WD40 subunits. However, molecular mechanisms underlying transcriptional regulation of these MBW subunits remain largely elusive. In this study, we isolated an Arabidopsis mutant that displays a constitutive red color in aboveground tissues with retarded growth phenotypes. In the presence of sucrose, the mutant accumulates more than 3-fold anthocyanins of the wild type(WT), but cannot produce anthocyanins as WT in the absence of sucrose. Map-based cloning results demonstrated that the mutation occurs in the locus At4 G01000, which encodes a conserved nuclear-localized ubiquitin-like(UBL) superfamily protein, silencing defective 2(SDE2), in eukaryotes. SDE2 is ubiquitously expressed in various tissues. In the sucrose-induced anthocyanin biosynthesis, SDE2 expression was not responded to sucrose treatment at the early stage but was enhanced at the late stage. SDE2 mutations result in upregulation of anthocyanin biosynthetic and regulatory genes. Yeast-two hybrid analysis indicated that SDE2 has no direct interaction with the MYB transcription factor PAP1 and b HLH factor TT8, indicating that SDE2 is a indirect factor to affect anthocyanin accumulation. Taking together, our data suggest that SDE2 may play a role in finely coordinating anthocyanin biosynthesis with other biological processes.

关键词： Anthocyanin biosynthesis Sucrose SDE2 PAP1 Arabidopsis

SiC-Si-ZrSiO_4 Multiphase Oxidation Protective Coating for Carbon/Carbon Composites

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journal of Materials Science & Technology 2008年第6期24卷 941-944页

作者： yulei ZHANG Hejun LI Qiangang FU Kezhi LI Dangshe HOU C/C Composites Technology Research Center Laboratory of Superhigh Temperature Composites Northwestern Polytechnical University Xi/an 710072 China

In order to improve the anti-oxidation property of carbon/carbon （C/C） composites, a novel SiC-Si-ZrSiO4 multiphase oxidation protective coating was produced on the surface of C/SiC coated carbon/carbon compo ites by a pack cementation technique. The phase composition and microstructure of the as-prepared coatings were characterized by XRD （X-ray diffraction）, SEM （scanning electron microscopy） and EDS （energy dispersive spectroscopy）. Oxidation behavior of the multiphase coated C/C composites was also investigated. It showed that the as-prepared coating characterized by excellent oxidation resistance and thermal shock re- sistance could effectively protect C/C composites from oxidation at 1773 K for 57 h in air and endure the thermal cycle between 1773 K and room temperature for 12 times, whereas the corresponding weight loss is only 1.47%. The excellent oxidation protective ability of the SiC-Si-ZrSiO4 coating could be attributed to the C/SiC gradient inner layer and the multiphase microstructure of the coating.

关键词： Carbon/carbon composites Oxidation Coating

Initial precursor reaction mechanism of CVD-HfC coating based on density functional theory

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Chinese journal of Aeronautics 2024年第7期37卷 511-521页

作者： Yunzhou LIN yulei ZHANG Yanqin FU jian ZHANG jing’an KONG Ruicong CHEN State Key Laboratory of Solidification Processing Carbon/Carbon Composites Research CenterNorthwestern Polytechnical UniversityXi’an 710072China Henan Key Laboratory of High Performance Carbon Fiber Reinforced Composites Carbon Matrix Composites Research InstituteHenan Academy of SciencesZhengzhou 450046China

Recently,the preparation of ultra-high temperature HfC ceramic coating has gained significant attention,particularly through the application of the HfCl_(4)-CH_(4)-H_(2)-Ar system via Chemical Vapor Deposition(CVD),which has been found widely applied to C/C ***,an analysis of the reactions that occur in the initial stage of the CVD-HfC coating process is presented using Density Functional Theory(DFT)and Transition State Theory(TST)at the B3LYP/Lanl2DZ *** results reveal that HfCl4 can only cleave to produce hypochlorite,which will further react with methyl to synthesize intermediates to form *** to the analysis of the energy barrier and reaction constant,HfCl preferentially reacts with methyl groups to form complex adsorptive intermediates at 1573 *** a C—Hf bond production energy of 212.8 kcal/mol(1 kcal=4.18 kj),the reaction rate constant of HfCl+CH is calculated to be 2.15×10^(-18) cm^(3)/s at 1573 ***,both the simulation and experimental results exhibit that the upward trend of reaction rate constants with temperature is also consistent with the deposition rate,indicating that the growth curve of the reaction rate constants tends to flatten *** proposed reaction model of the precursor’s decomposition and reconstruction during deposition process has significant implication for the process guidance.

关键词： Carbon composite HfC coating Chemical vapor deposition Density functional theory Precursor reaction mechanism

Rapid differentiation of simple saccharides based on cluster ions by paper spray tandem mass spectrometry

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Chinese Chemical Letters 2022年第11期33卷 4808-4816页

作者： Wangmin Hu Tianyi Li yulei Yang Shanshan jia Mei Zhang School of Chinese Materia Medica Beijing University of Chinese MedicineBeijing 102488China National Institute for Communicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 102206China

Simple saccharides have a variety of biological functions,but their structural diversity and inherent structural features pose a major challenge for rapid *** this work,we developed a derivative-free and ion mobility-free method for the rapid analysis of monosaccharides and disaccharides using paper spray tandem mass *** cluster ions consisting of saccharide analytes,ligands and transition metal ions are used as precursor *** defined the R-value as the ratio of the intensity of the product ion that loses one molecule of ligand over the intensity of the product ion that loses one molecule of saccharide via collision induced dissociation(CID).The species and conformation of simple saccharides can be easily differentiated by calculating this *** the capability of directly analyzing clinical samples using paper spray ionization,our method can be used to rapidly quantify the molar ratio of galactose to glucose in dried plasma samples to aid in the diagnosis of *** analytical strategy provided herein has good potential to be applied to a wide range of saccharide analysis applications in the future.

关键词： Simple saccharide Rapid structure differentiation Paper spray Tandem mass spectrometry