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Gas–solid reactor optimization based on EMMS-DPM simulation and machine learning

Particuology 2024年第6期89卷 131-143页

作者： haolei Zhang Aiqi Zhu ji Xu wei Ge State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing 100190China

Design,scaling-up,and optimization of industrial reactors mainly depend on step-by-step experiments and engineering experience,which is usually time-consuming,high cost,and high *** numerical simulation can reproduce high resolution details of hydrodynamics,thermal transfer,and reaction process in reactors,it is still challenging for industrial reactors due to huge computational *** this study,by combining the numerical simulation and artificial intelligence(AI)technology of machine learning(ML),a method is proposed to efficiently predict and optimize the performance of industrial reactors.A gas–solid fluidization reactor for the methanol to olefins process is taken as an example.1500 cases under different conditions are simulated by the coarse-grain discrete particle method based on the Energy-Minimization Multi-Scale model,and thus,the reactor performance data set is *** develop an efficient reactor performance prediction model influenced by multiple factors,the ML method is established including the ensemble learning strategy and automatic hyperparameter optimization technique,which has better performance than the methods based on the artificial neural ***,the operating conditions for highest yield of ethylene and propylene or lowest pressure drop are searched with the particle swarm optimization algorithm due to its strength to solve non-linear optimization *** show that decreasing the methanol inflow rate and increasing the catalyst inventory can maximize the yield,while decreasing methanol the inflow rate and reducing the catalyst inventory can minimize the pressure *** two objectives are thus conflicting,and the practical operations need to be compromised under different circumstance.

关键词： Discrete particle method Artificial intelligence Machine learning Particle swarm optimization Industrial reactor optimization

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Lift-Off Effect of Koch and Circular Differential Pickup Eddy Current Probes

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 283-293页

作者： Guolong Chen Zheng Cao Shuaishuai Zhang ji wei wei Gao Wuyin jin School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050China

A flexible or planar eddy current probe with a differential structure can suppress the lift-off noise during the inspection of ***,the extent of the lift-off effect on differential probes,including different coil structures,*** this study,two planar eddy current probes with differential pickup structures and the same size,Koch and circular probes,were used to compare lift-off *** eddy current distributions of the probes perturbed by 0°and 90°cracks were obtained by finite element *** analysis results show that the 90°crack can impede the eddy current induced by the Koch probe even further at relatively low lift-off *** peak-to-peak values of the signal output from the two probes were compared at different lift-off distances using finite element analysis and experimental *** addition,the effects of different frequencies on the lift-off were studied *** results show that the signal peak-to-peak value of the Koch probe for the inspection of cracks in 90°orientation is larger than that of the circular probe when the lift-off distance is smaller than 1.2 *** addition,the influence of the lift-off distance on the peak-to-peak signal value of the two probes was studied via *** indicates that the influence becomes more evident with an increase in excitation *** research discloses the lift-off effect of differential planar eddy current probes with different coil shapes and proves the detection merit of the Koch probe for 90°cracks at low lift-off distances.

关键词： Eddy current testing Differential pickup probe Fractal Koch curve Flexible eddy current probe

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Cloud-Model-Based Feature Engineering to Analyze the Energy-Water Nexus of a Full-Scale Wastewater Treatment Plant

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Engineering 2024年第5期36卷 63-75页

作者： Shan-Shan Yang Xin-Lei Yu Chen-hao Cui jie Ding Lei He wei Dai Han-Jun Sun Shun-Wen Bai Yu Tao ji-wei Pang Nan-Qi Ren State Key Laboratory of Urban Water Resource and Environment Harbin Institute of TechnologyHarbin 150000China Key Laboratory of Environmental Biotechnology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Civil and Environmental Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China China Energy Conservation and Environmental Protection Group Beijing 100089China

Wastewater treatment plants(WWTPs)are important and energy-intensive municipal *** energy consumption and relatively low operating performance are major challenges from the perspective of carbon ***,water-energy nexus analysis and models for WWTPs have rarely been reported to *** this study,a cloud-model-based energy consumption analysis(CMECA)of a WWTP was conducted to explore the relationship between influent and energy consumption by clustering its influent’s *** principal component analysis(PCA)and K-means clustering were applied to classify the influent condition using water quality and volume *** energy consumption of the WWTP is divided into five standard evaluation levels,and its cloud digital characteristics(CDCs)were extracted according to bilateral constraints and golden ratio *** results showed that the energy consumption distribution gradually dispersed and deviated from the Gaussian distribution with decreased water concentration and *** days with high energy efficiency were extracted via the clustering method from the influent category of excessive energy consumption,represented by a compact-type energy consumption distribution curve to identify the influent conditions that affect the steady distribution of energy *** local WWTP has high energy consumption with 0.3613 kW·h·m^(-3)despite low influent concentration and volumes,across four consumption levels from low(I)to relatively high(IV),showing an unsatisfactory operation and management *** average oxygenation capacity,internal reflux ratio,and external reflux ratio during high energy efficiency days recognized by further clustering were obtained(0.2924-0.3703 kg O_(2)·m^(-3),1.9576-2.4787,and 0.6603-0.8361,respectively),which could be used as a guide for the days with low energy ***,this study offers a water-energy nexus analysis method to identify influent conditions with operational manageme

关键词： Wastewater treatment plants Cloud-model theory Data mining Principal component analysis K-means clustering Cloud-model-based energy consumption analysis

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A new strain-based pentagonal membrane finite element for solid mechanics problems

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Theoretical & Applied Mechanics Letters 2024年第3期14卷 211-216页

作者： wei hao Koh Logah Perumal CheeKuang Kok Faculty of Engineering and Technology Multimedia UniversityMelaka 75450Malaysia

Polygonal finite elements remain an attractive option in finite element analysis due to their flexibility in modelingarbitrary shapes compared to *** this study,a pentagonal membrane element was developed with thestrain approach for the first *** element possesses invariance,and the equilibrium constraint was appliedto the assumed strain field using corrective *** by the advancing front technique,a pentagonalmesh was generated,and the mesh quality was enhanced with Laplacian *** performance of thedeveloped pentagonal element was assessed in a few numerical tests,and the results revealed its suitability inmodeling the bending of ***,the numerical results are enhanced when pentagonal elements are usedin mesh transitions along boundaries to smoothen curved edges and capture distributed loads.

关键词： Strain-based pentagonal element Corrective coefficients EquilibriumLaplacian smoothing Pentagonal mesh Mesh transition

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Immune function of erythrocytes in patients with chronic venous insufficiency of the lower extremities

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Chinese Medical Journal 2007年第24期120卷 2224-2228页

作者： ZHANG Lan ZHANG Bai-gen ZHANG ji-wei ZHANG hao Department of Vascular Surgery Renji Hospital School of Medicine Shanghai Jiaotong University Shanghai 200127 China

Background The influence of inflammatory processes has been one of the hot topics in discussions of the etiology of chronic venous insufficiency （CVI）. Erythrocytes are very important in controlling inflammatory immunity and innate immune reactions. The purpose of this study was to analyze the correlation between the development of CVI and the change of CD35, Fy6 on erythrocytes, and interleukin-8 （IL-8） levels. Methods A group of 43 patients with CVI were studied in parallel with 8 healthy individuals serving as control subjects. Control subjects were those with normal findings on lower extremity duplex examinations. We used an erythrocyte flow cytometer to examine the expression of both CD35 and Fy6 on red blood cells, and an enzyme-linked immunosorbent assay analysis method to measure plasma IL-8 levels. We also analyzed the change of IL-8 levels under the influence of erythrocytes using a modified method of the hemaimmune reaction. Results Compared with normal control subjects, CD35 expression increased significantly among patients with CVI classified as C4 without lipodermatosclerosis, but tended to decrease and reach the lowest level among patients classified as C5-C6. Fy6 expression increased significantly among patients in the early stages of CVI, but tended to decrease remarkably among patients classified as C5-C6. The inflammatory response intensified at the C5-C6 classification, where high levels of IL-8 coexisted with a low expression of Fy6. The increase in IL-8 in the CVI group was higher than in the control group in association with the complete blood cells, regardless of the presence of erythrocytes, when inactive tumour cells were added, whereas the level of IL-8 in the CVI group was significantly lower than in the control group. Conclusions Abnormalities of erythrocyte innate immunity represents a fundamental derangement in CVI. These inadequate inflammatory responses may lead to local tissue and microvascular damage of the lower extremity.

关键词： venous insufficiency erythrocytes natural immunity

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On optimal streaming kernelization algorithms

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Science China(Information Sciences) 2024年第8期67卷 337-338页

作者： hao FENG wei YANG jianer CHEN School of Computer Science Guangzhou University Department of Computer Science and Engineering Texas A&M University

The streaming model has been a popular model in big data computation. Streaming kernelization algorithms can be regarded as data compression processes on streaming data. In this study, we give a general method for developing computational lower bounds for streaming kernelization algorithms that is applicable to a large class of computational problems. As an example, we use the method to prove computational lower bounds for the well-known problem d-Hi TTin GSET.

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Index-free triangle-based graph local clustering

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Frontiers of Computer Science 2024年第3期18卷 143-153页

作者： Zhe YUAN Zhewei wei Fangrui LV ji-Rong WEN The Country and Area Studies Academy Beijing Foreign Studies UniversityBeijing 100089China Gaoling School of Artificial Intelligence Renmin University of ChinaBeijing 100872China

Motif-based graph local clustering(MGLC)is a popular method for graph mining tasks due to its various ***,the traditional two-phase approach of precomputing motif weights before performing local clustering loses locality and is impractical for large *** some attempts have been made to address the efficiency bottleneck,there is still no applicable algorithm for large scale graphs with billions of *** this paper,we propose a purely local and index-free method called Index-free Triangle-based Graph Local Clustering(TGLC^(*))to solve the MGLC problem w.r.t.a ***^(*)directly estimates the Personalized PageRank(PPR)vector using random walks with the desired triangleweighted distribution and proposes the clustering result using a standard sweep *** demonstrate TGLC^(*)’s scalability through theoretical analysis and its practical benefits through a novel visualization ***^(*)is the first algorithm to solve the MGLC problem without precomputing the motif *** experiments on seven real-world large-scale datasets show that TGLC^(*)is applicable and scalable for large graphs.

关键词： graph local clustering triangle motif index-free sampling method visualization

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Synergistic effects of chemical additives and mature compost on reducing H_2S emission during kitchen waste composting

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Journal of Environmental Sciences 2024年第5期139卷 84-92页

作者： Yongdi Liu Haihou Wang hao Zhang Yueyue Tao Rui Chen Sheng Hang Xiaoyan Ding Meidi Cheng Guochun Ding Yuquan wei Ting Xu ji Li College of Resources and Environmental Science Beijing Key Laboratory of Biodiversity and Organic FarmingChina Agricultural UniversityBeijing 100193China Organic Recycling Institute(Suzhou)of China Agricultural University Wuzhong DistrictSuzhou 215128China Suzhou Academy of Agricultural Sciences Institute of Agricultural Sciences in Taihu Lake DistrictSuzhou 215155China Technical Centre for Soil Agriculture and Rural Ecology and EnvironmentMinistry of Ecology and EnvironmentBeijing 100012China College of Chemistry and Chemical Engineering Yantai UniversityYantai 264005China

Additives could improve composting performance and reduce gaseous emission,but few studies have explored the synergistic of additives on H_(2)S emission and compost *** research aims to make an investigation about the effects of chemical additives and mature compost on H_(2)S emission and compost maturity of kitchen waste *** results showed that additives increased the germination index value and H_(2)S emission reduction over 15 days and the treatment with both chemical additives and mature compost achieved highest germination index value and H_(2)S emission reduction(85%).Except for the treatment with only chemical additives,the total sulfur content increased during the kitchen waste *** proportion of effective sulfur was higher with the addition of chemical additives,compared with other *** relative abundance of H_(2)S-formation bacterial(Desulfovibrio)was reduced and the relative abundance of bacterial(Pseudomonas and Paracoccus),which could convert sulfur-containing substances and H_(2)S to sulfate was improved with *** the composting process with both chemical additives and mature compost,the relative abundance of Desulfovibrio was lowest,while the relative abundance of Pseudomonas and Paracoccus was *** together,the chemical additives and mature compost achieved H_(2)S emission reduction by regulating the dynamics of microbial community.

关键词： Kitchen waste composting Sulfur conversion Chemical additives Mature compost Microbial community

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Activity promotion of Rh_(1)Ca_(x)/Al_(2)O_(3) single-atom catalyst in 1-octene hydroformylation:a volcano curve exists between Ca adding ratio and catalytic activity

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Science China Chemistry 2024年第4期67卷 1187-1192页

作者： hao Zhang Xingcong Zhang Xilun Wang Qingdi Sun hao Liu Hongbing ji Xiaohui He Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education Fine Chemical Industry Research InstituteSchool of ChemistryIGCMESun Yat-sen UniversityGuangzhou 510275China Huizhou Research Institute Sun Yat-sen UniversityHuizhou 516081China State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology Institute of Green Petroleum Processing and Light Hydrocarbon ConversionCollege of Chemical EngineeringZhejiang University of TechnologyHangzhou 310014China

Single-atom catalysts(SACs)are considered the best candidates for olefin hydroformylation due to their combined advantages of homogeneous and heterogeneous *** conventional organo-phosphine modification,Rh SAC is modified by introducing Ca,resulting in a significant increase in activity(maximum~5.7-fold)and ***,a volcano curve between Ca addition ratio and catalytic activity is *** Ca significantly increases activity by decreasing the energy barrier,but excessive Ca decreases activity due to hindering substrate adsorption and reaction.

关键词： hydroformylation bimetallic single-atom catalysts rhodium heterogeneous catalyst

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A comparative investigation on wear behaviors of physical and chemical vapor deposited bronze coatings for hydraulic piston pump

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Chinese Journal of Aeronautics 2024年第3期37卷 391-403页

作者： wei hao Andrews LARBI Hongkang DONG Dongyun WANG Shenghu LI Zhejiang Provincial Key Laboratory of Urban Rail Transit Intelligent Operation and Maintenance Technology and Equipment Zhejiang Normal UniversityJinhua 321004China College of Engineering Zhejiang Normal UniversityJinhua 321004China Hangzhou Lilong Hydraulic Co. LtdHangzhou 311200China

The cylinder block/valve plate interface is one of the most critical frictional interfaces of the swashplate-type axial piston ***,the poor lubrication interface caused rapid wear and high friction loss in an elastohydrodynamic lubrication system,decreasing the pump *** resistant bronze coatings were fabricated on 38CrMoAl substrate by Physical Vapor Deposition(PVD)and Chemical Vapor Deposition(CVD),***-on-disc wear tests were performed to comparatively investigate the wear behaviors of the coatings and bulk ductile iron *** can be found that the PVD-bronze coating exhibited better wear resistance than the other two *** enhanced wear resistance was attributed to the unique composite microstructure and desired mechanical strength,which could resist to mechanical shear and spallation,decreasing friction *** appropriate hardness of(1.33±0.07)GPa could be beneficial for enhancing its wear *** PVD-bronze coating possessed a much lower and stable coefficient of friction(about 0.1)and wear rate(about 6000μm3.N-1.m-1)under the loading forces of about 100 N after 20 *** wear mechanism was the abrasive wear.

关键词： Aircraft hydraulic pump Bronze Coatings Wear resistance Mechanisms

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