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Quadrature-based moment methods for the population balance equation: An algorithm review

Chinese Journal of Chemical Engineering 2019年第3期27卷 483-500页

作者： Dongyue li zhipeng li Zhengming Gao State Key Laboratory of Chemical Resource Engineering School of Chemical Engineering Beijing University of Chemical Technology State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

The dispersed phase in multiphase flows can be modeled by the population balance model(PBM). A typical population balance equation(PBE) contains terms for spatial transport, loss/growth and breakage/coalescence source terms. The equation is therefore quite complex and difficult to solve analytically or numerically. The quadrature-based moment methods(QBMMs) are a class of methods that solve the PBE by converting the transport equation of the number density function(NDF) into moment transport equations. The unknown source terms are closed by numerical quadrature. Over the years, many QBMMs have been developed for different problems, such as the quadrature method of moments(QMOM), direct quadrature method of moments(DQMOM),extended quadrature method of moments(EQMOM), conditional quadrature method of moments(CQMOM),extended conditional quadrature method of moments(ECQMOM) and hyperbolic quadrature method of moments(Hy QMOM). In this paper, we present a comprehensive algorithm review of these QBMMs. The mathematical equations for spatially homogeneous systems with first-order point processes and second-order point processes are derived in detail. The algorithms are further extended to the inhomogeneous system for multiphase flows, in which the computational fluid dynamics(CFD) can be coupled with the PBE. The physical limitations and the challenging numerical problems of these QBMMs are discussed. Possible solutions are also summarized.

关键词： Population balance equation Quadrature-based moment method Multiphase flow Computational fluid dynamics

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Compressibility induced bubble size variation in bubble column reactors:Simulations by the CFD–PBE

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Chinese Journal of Chemical Engineering 2018年第10期26卷 2009-2013页

作者： Dongyue li zhipeng li Zhengming Gao State Key Laboratory of Chemical Resource Engineering School of Chemical Engineering Beijing University of Chemical Technology

Bubble column reactors can be simulated by the two fluid model(TFM) coupled with the population balance equation(PBE). For the large industrial bubble columns, the compressibility due to the pressure difference may introduce notable bubble size variation. In order to address the compressibility effect, the PBE should be reformulated and coupled with the compressible TFM. In this work, the PBE with a compressibility term was formulated from single bubble dynamics, the mean Sauter diameters predicted by the compressible TFM coupled with the PBE were compared with the analytical solutions obtained by the ideal gas law. It was proven that the mesoscale formulations presented in this work were physically consistent with the macroscale modeling. It can be used to simulate large industrial plants when the compressibility induced bubble size variation is important.

关键词： Bubble column reactors Computational fluid dynamics Population balance equation Compressibility

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Damage assessment and diagnosis of hydraulic concrete structures using optimization-based machine learning technology

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Frontiers of Structural and Civil Engineering 2023年第8期17卷 1281-1294页

作者： Yantao ZHU Qiangqiang JIA Kang ZHANG Yangtao li zhipeng li Haoran WANG State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China National Dam Safety Research Center Wuhan 430010China Changjiang Institute of Survey PlanningDesignand ResearchWuhan 430010China

Concrete is widely used in various large construction projects owing to its high durability,compressive strength,and ***,the tensile strength of concrete is low,and concrete cracks *** in the concrete structure will result in changes in parameters such as the frequency mode and curvature mode,which allows one to effectively locate and evaluate structural *** this study,the characteristics of the curvature modes in concrete structures are analyzed and a method to obtain the curvature modes based on the strain and displacement modes is ***,various indices for the damage diagnosis of concrete structures based on the curvature mode are introduced.A damage assessment method for concrete structures is established using an artificial bee colony backpropagation neural network *** proposed damage assessment method for dam concrete structures comprises various modal parameters,such as curvature and *** feasibility and accuracy of the model are evaluated based on a case study of a concrete gravity *** results show that the damage assessment model can accurately evaluate the damage degree of concrete structures with a maximum error of less than 2%,which is within the required accuracy range of damage identification and assessment for most concrete structures.

关键词： hydraulic structure curvature mode damage detection artifical neural network artificial bee colony

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Effects of dietary replacement of soybean meal with dried distillers grains with solubles on the microbiota occupying different ecological niches in the rumen of growing Hu lambs

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Journal of Animal Science and Biotechnology 2021年第2期12卷 677-688页

作者： Junshi Shen zhipeng li Zhongtang Yu Weiyun Zhu Laboratory of Gastrointestinal Microbiology Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal HealthCollege of Animal Science and TechnologyNanjing Agricultural UniversityNanjing 210095China National Center for International Research on Animal Gut Nutrition Nanjing Agricultural UniversityNanjing 210095China Department of Special Animal Nutrition and Feed Science Institute of Special Animal and Plant SciencesChinese Academy of Agricultural SciencesChangchun 130112China Department of Animal Sciences The Ohio State UniversityColumbusOH 43210USA

Background:Diet has a profound impact on the rumen microbiota,and the impact can vary among the different rumen ecological niches(REN).This study investigated the effects of dietary replacement of soybean meal(SBM)with dried distillers grains with solubles(DDGS)on the rumen microbiota occupying different REN of growing Hu *** a 9-week feeding trial,6 lambs from each dietary treatment(SBM ***-based diets)were slaughtered for sample *** microbiota of the rumen solid,liquid,and epithelium fractions was examined using amplicon sequencing analysis of bacterial 16S rRNA gene,functional prediction,and ***:No interaction of dietary protein source(PS)and REN were detected for virtually all the measurements made in this *** DDGS substitution resulted in very limited influence on bacterial community ***,the metabolic pathways predicted from 16S rRNA gene sequences varied greatly between SBM-and DDGS-based *** populations of rumen total bacteria,fungi,sulfate-reducing bacteria(SRB),and methanogens were not influenced by DDGS substitution,but the population of protozoa was *** bacterial communities in rumen solid(RS)and liquid(RL)were similar in taxonomic composition but were different in relative abundance of some *** contrast,the bacterial composition and relative abundance of rumen epithelium(RE)were greatly distinct from those of the RS and the *** alignment with the bacterial relative abundance,the metabolic pathways predicted from 16S rRNA genes also varied greatly among the different *** populations of total bacteria,protozoa,and methanogens attached to the RE were smaller than those in the RS and RL,and the fungal population on the rumen epitheliumwas smaller than that in the RS but similar to that in the *** the contrary,the SRB population on the RE was greater than that in the RS and ***:Substitution of SBM with DDGS had greater impact to the protozoa than to the other microbes,and

关键词： Distillers dried grains with solubles Growing lamb Microbiota Ruminal ecological niche Soybean meal

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Source enumeration method by combining diagonal loading and constructing second-order statistics

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The Journal of China Universities of Posts and Telecommunications 2023年第1期30卷 47-55页

作者： Wang Chuanchuan Zeng Yonghu Wang liandong li zhipeng State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System Luoyang 471003China

A source enumeration method based on diagonal loading of eigenvalues and constructing second-order statistics is proposed,for the case that the antenna array observed signals are overlapped with spatial colored noise,and the number of antennas compared with the number of snapshots meet the requirement of general asymptotic ***,the sample covariance matrix of the observed signals is obtained,the eigenvalues of the sample covariance matrix can be acquired by eigenvalue decomposition,and the eigenvalues are diagonally loaded,and a new formula for calculating the diagonal loading is *** on the diagonal loaded eigenvalues,the difference values are calculated for the adjacent eigenvalues after diagonal loading,and the statistical variance of the difference values is *** this basis,the second-order statistics of the difference values are constructed,and when the second-order statistics are minimized,the corresponding number of sources is *** proposed method has wide applicability,which is suitable for both general asymptotic regime and classical asymptotic system,and is suitable for both white Gaussian noise environment and colored noise *** method makes up for the lack of source enumeration methods in the case of general asymptotic system and colored noise.

关键词： source enumeration general asymptotic regime colored noise diagonal loading second-order statistics

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Delaminating Ti3C2 MXene by blossom of ZnIn2S4 microflowers for noble-metal-free photocatalytic hydrogen production

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Journal of Materials Science & Technology 2022年第25期120卷 89-98页

作者： Weixin Huang zhipeng li Chao Wu Hanjie Zhang Jie Sun Qin li Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&Hubei Key Laboratory of Catalysis and Materials Science South-Central Minzu UniversityWuhan430074China

Herein,a novel strategy was exploited to achieve the delamination of TiCMXene multilayers into ultrathin flakes by blossom of ZnInSmicroflowers via a one-pot solvothermal *** is no need to peel off the MXene bulk ahead of its combination with the *** obtained ZnInS/TiCbinary composites were applied for visible-light-driven photocatalytic hydrogen production without noble metal cocatalyst,and the optimized sample exhibited a hydrogen-production efficiency of 978.7 μmol hgwith the corresponding apparent quantum efficiency of 24.2% at 420 nm,which was 2.7 times higher than bare *** the comprehensive analysis based on spectroscopy measurements,electrochemical techniques and energy band theory,such enhancement was mainly attributed to(1) the highly-exposed surface that was beneficial for the adequate exposure of reactive sites and(2)the intimate contact interface that favored the transfer of photogenerated *** study provides a new way of thinking for synthesizing ultrathin MXene-based composite materials for noble-metal-free and highly-efficient photocatalysis applications.

关键词： ZnIn2S4 Ti3C2 MXene Photocatalysis Hydrogen production

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Periodic event-triggered secure consensus for networked mechanical systems under Denial-of-Service attacks

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Control Theory and Technology 2024年第1期22卷 1-13页

作者： Shiqi Zheng zhipeng li Chao Zhai Peng Shi School of Automation China University of GeosciencesWuhan430074HubeiChina School of Electrical and Electronic Engineering The University of AdelaideAdelaideSA5005Australia School of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou350100FujianChina

This paper concentrates on the secure consensus problem of networked mechanical/Euler–Lagrange ***,a new periodic event-triggered(PET)secure distributed observer is proposed to estimate the leader *** proposed distributed observer only relies on the PET data from its neighbors,which can significantly reduce the communication and computational *** importantly,it is secure in the sense that it can work normally regardless of the Denial-of-Service(DoS)***,based on the proposed distributed observer,an adaptive fuzzy control law is proposed for each Euler–Lagrange system.A PET mechanism is integrated into the controller,which can reduce the control *** is helpful for both energy saving and fault tolerance of ***,the PET mechanism naturally makes the controller easy to be implemented in digital *** property of fuzzy logic systems and Gronwall inequality are skillfully utilized to show the stability of the closed-loop ***,the proposed control scheme is verified on real Euler–Lagrange systems,which contain a robot manipulator and several servo motors.

关键词： Output regulation Mechanical/Euler-Lagrange systems Periodic event-triggered mechanism Denial-of-Service attacks

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Comprehensive insights:unraveling the mechanisms of gut commensals in glucose metabolism regulation

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Science China(life Sciences) 2024年第2期67卷 414-417页

作者： zhipeng li Qixing Nie Shao-Ping Nie State Key Laboratory of Food Science and Resources China-Canada Joint Lab of Food Science and Technology(Nanchang)Key Laboratory of Bioactive Polysaccharides of Jiangxi ProvinceNanchang UniversityNanchang 330047China

The prevalence of type 2 diabetes(T2D)has escalated to a global epidemic,garnering widespread *** research utilizing germ-free(GF)mice,antibiotic treatments,and fecal microbiota transplantation approaches has established the critical role of gut microbiota in modulating glucose *** microbiota interacts with diets and the mucosal immune system,influencing intestinal permeability and the penetration of microbial products.

关键词： metabolism utilizing insight

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Numerical investigation of proppant transportation characteristics in hydraulically fractured wedge fractures

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Petroleum 2024年第4期10卷 660-671页

作者： Xiaofeng Sun Jinxin Bao zhipeng li Jingyu Qu Key Laboratory of Enhanced Oil and Gas Recovery of Ministry of Education Northeast Petroleum University Sanya Offshore Oil & Gas Research Institute Northeast Petroleum University China Petroleum Bohai Drilling Engineering Co. Ltd.Fourth Drilling Engineering Branch

Hydraulic fracturing creates multiple induced fractures and micro-fractures, forming a complex fracture network in the reservoir. The study of the transport and distribution of the proppant within the fracture network is critical to the design and evaluation. However, existing simulation studies of proppant transport tend to be overly idealized and neglect the inhomogeneity of fracture widths that occur after fracturing. To address these issues, this study employs computational fluid dynamics(CFD) to study the transportation of fracturing fluid and proppant within a fracture network. The flow dynamics of solidliquid two-phase flow in fractures are simulated using the Euler-Euler multiphase flow model. Considering the actual variables in field construction and the inherent inhomogeneity in realistic fracture structures, a three-dimensional model was established to capture the gradual variation in fracture *** accuracy of this model was verified through a comparative analysis with physical experiments. On this basis, an investigation was conducted to explore the impact of particle size, particle density, particle volume concentration, and injection velocity on proppant transportation. The results demonstrate that,in contrast to conventional rectangular fractures, sandbanks formed from wedge fractures exhibit a lower height, which facilitates improved transportation into deeper fractures. Furthermore, particle concentration primarily influences distal fractures, with proppant particle size being second. The injection velocity has a significant impact on the height of the sandbank located in proximity to the fracture *** research findings provide a deeper understanding of the transport and distribution of proppants within wedge fractures, thereby establishing a theoretical basis for the analysis and engineering guidance in on-site hydraulic fracturing construction.

关键词： Proppant transport Wedge fracture Computational fluid dynamics (CFD) Particle-fluid flow Hydraulic fracturing

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Investigation of extraction fraction in confined impinging jet reactors for tri-butyl-phosphate extracting butyric acid process

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Chinese Journal of Chemical Engineering 2016年第2期24卷 310-316页

作者： Zhengming Gao Manting Zhao Yun Yu zhipeng li Jing Han State Key Laboratory of Chemical Resource Engineering School of Chemical EngineeringBeijing University of Chemical Technology Beijing Aircraft Maintenance & Engineering Co. LTD

The extraction fraction E and overall volumetric mass transfer coefficient kka of TBP extracting butyric acid pro- cess in confined impinging jet reactors （CIJR） with two jets were investigated. The main variables tested were the concentration of tri-butyl-phosphate （TBP） and butyric acid, the impinging velocity V, the impinging velocityratio of two phases Vorg/Vaq, the nozzle inner diameter di and the distance L between the jet axes and the top wall of the impinging chamber. The results showed that E and kLa increase with an increase of the impinging velocity V, the concentration ofTBP Corg, and the impinging velocity ratio Vor/Vaq. However, E and kta decrease with an increase of the inner diameter d1 from 1 to 2 mm, the concentration of butyric acid Caq from 0.5% （v/v） to 2% （v/v）. The factor L ranging from 3 to 11 mm has a negligible effect on E and kLa. A correlation on these variables and kLa was proposed based on the experimental data. These results indicated good mass transfer oerformance of CIJR in the extraction operation.

关键词： Confined impinging jet reactors (CIJR) Extraction fraction Mass transfer coefficient Extraction process

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