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

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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

Screening current in ultra-high-field non-insulated superconducting magnets

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Science China(Technological sciences) 2024年第7期67卷 2255-2273页

作者： ZHOU BenZhe WANG Lei CHEN Yong WANG QiuLiang WANG KangShuai ZHANG ZiLi LIU JianHua University of Chinese academy of sciences Beijing 100049China Institute of Electrical engineering Chinese Academy of SciencesBeijing 100190China

Screening current is recognized as one of the critical elements limiting the progression of superconducting magnets toward achieving higher magnetic fields. Currently, most non-insulated(NI) superconducting magnets consider the magnet as insulated when addressing the issue of screening current. However, the bypass current in the NI magnet can modify the actual history of magnetization, so the screening current in NI magnet will be different from that in the insulated magnet. This paper presents a novel method based on the homogenized T-A formulation(T is the current vector potential, and A is the magnetic vector potential), which enables real-time simulation of both the bypass current behavior and the implications of screening current in NI superconducting magnets, even when these magnets contain tens of thousands of turns. We have developed a 32 T NI hybrid superconducting magnet and validated the effectiveness of this method through experiments. Employing this efficacious method,we conducted a comprehensive calculation of screening current in NI magnets, comparing them with insulated magnets in terms of screening current-induced stress(SCIS), screening current-induced field(SCIF), and losses. The results indicate that in the NI insert coils, the sequential excitation of background coils and insert coils induces a reverse screening current, resulting in slightly lower SCIF and SCIS compared to those in the insulated magnets. The method and results can contribute to the enhancement of magnet design and provide valuable insights for the development of ultra-high fields(UHF) NI magnets.

关键词： ultra-high-field superconducting magnet screening current REBCO coil NI coil stress loss

Flame Synthesis of Zr/ZSM-5 Catalysts with Tunable Acidity for the Oxidative Dehydrogenation of Propane to Propene

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Journal of Thermal Science 2024年第1期33卷 268-283页

作者： DANIEL Samuel FONZEU MONGUEN Cedric Karel WU Lingnan TIAN Zhenyu Institute of engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese academy of sciences Beijing 100049China

Tuning the surface acidity of ZSM-5 catalyst is essential to achieve desired propene selectivity and *** several ratios of Zr were utilized to modify ZSM-5 via flame spray pyrolysis technique coupled with a pulse spray evaporation *** interaction between Zr and ZSM-5 in the flame influenced the physicochemical and acidity properties of the Zr/*** increasing Zr ratio in ZSM-5 shows coated layers of irregular nano-sized Zr with an increase in crystallite sizes due to the synergetic effect between Zr and *** surface chemical analysis revealed increased lattice oxygen on the Zr modified ZSM-5(1:4) sample compared to other *** acidity analysis revealed the Lewis and Br?nsted acid distribution in the weak and medium acid sites on the catalyst ***,the increase in Zr loading decreased the concentration of Br?nsted acid sites and tuned the catalyst surface to more Lewis acidity,promoting propene selectivity and hindering the over-oxidation of *** modified ZSM-5 catalysts were examined in a fixed bed reactor within 300℃-700℃ at a gas hourly space velocity(GHSV) of 6000 mL·g(catalysts)^(-1)·h^(-1) for the oxidative dehydrogenation of propane(ODHP) to *** the catalysts,Zr/ZSM-5(1:4) exhibited the best propene yield, with 57.19% propane conversion and 75.54% selectivity to propene and the highest *** work provides a promising strategy for tuning the surface acidity of ZSM-5 with Zr for ODHP applications.

关键词： flame synthesis Zr modified ZSM-5 catalyst ODHP surface acidity lattice oxygen

Simulation of the L-valve in the circulating fluidized bed with a coarse-grained discrete particle method

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Particuology 2024年第7期90卷 266-280页

作者： Ruixiang Tang Zheng Zou Ji Xu Junwu Wang Qingshan Zhu Hongzhong Li State Key Laboratory of Mesoscience and engineering Institute of Process EngineeringChinese Academy of SciencesP.O.Box 353Beijing100190China School of Chemical engineering University of Chinese Academy of SciencesBeijing100049China Innovation academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

Stable and controllable solid flow is essential in circulating fluidized bed (CFB) systems. The L-valve is a typical non-mechanical valve that can provide flexible solid feeding. The investigation of the solid circulation rate and the hydrodynamic characteristics of the L-valve is crucial to its design and operation. The gas-solid flow in the L-valve of a full-loop CFB is studied with the coarse-grained discrete particle method (EMMS-DPM). Good agreements on the solid circulation rate and the pressure drop through the L-valve are achieved between the simulated and experimental data. The solid circulation rate increases linearly with the aeration velocity until the stable particle circulation of the CFB is destroyed. The flow patterns in the horizontal section of L-valve are gas-solid slug flow above the stationary solid layer and the moving solid layer, respectively. The effects of L-valve geometric parameters on the solid flow characteristics are also investigated. The results indicate that reducing the diameter and length of the horizontal section of L-valve can improve the solid transport efficiency, especially at low aeration velocity. Besides, the solid conveying capacity and flow stability are improved when the sharp bend of L-valve is modified to be a gradual bend.

关键词： L-valve Circulating fluidized bed Full loop Discrete particle method Gas-solid flow

Analysis of phase preservation and interferometric offset test in sparse SAR imaging

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Science China(Information sciences) 2024年第2期67卷 219-231页

作者： Zhongqiu XU Bingchen ZHANG Guangzuo LI Xueli ZHAN Yanfei BAO Yirong WU Key Laboratory of Spatial Information Processing and Application System Technology Chinese Academy of Sciences Aerospace Information Research Institute Chinese Academy of Sciences School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of Sciences PLA academy of Military sciences

Sparse synthetic aperture radar(SAR) imaging has emerged as a reliable microwave imaging scheme in the recent decade and excels in down-sampling reconstruction and full-sampling performance improvements such as noise, sidelobe, speckle, and ambiguity suppression. To utilize complex image products of sparse reconstruction for improvement in polarimetric, interferometric, and tomographic SAR imaging, it is necessary to evaluate the phase preservation of sparse SAR imaging. In this study, we first introduce the general alternating direction method of multipliers(ADMM) as the universal framework for sparse reconstruction algorithms and adopt chirp scaling algorithm(CSA)-based azimuth-range decouple operators to avoid expensive data storage and processing. Further, we theoretically analyze the phase preservation of the sparse reconstruction algorithm through a comparison with the reconstruction results of CSA. Finally,we conduct the interferometric offset test on the sparse reconstruction results of simulated and real Gaofen-3(GF-3) SAR data, demonstrating the phase-preserving ability of sparse methods.

关键词： sparse SAR imaging phase preservation interferometric offset test general ADMM azimuth-range decouple

Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao Ye Ji Xu Wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical engineering University of Chinese Academy of SciencesBeijing100049China Innovation academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

By modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid ***,a systematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty on the predictivity of the *** this study,collisions between predefined particle groups are analyzed to construct kernel functions for modeling the CGPs and then the model parameters are determined by equating the statistical properties of the CGPs and the real particles in the physical process *** approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation

PEGylated graphene oxide-mediated stimulation of vascular endothelial cells and responsive release of PD-1/PD-L1 inhibitor for efficient chemo-immunotherapy against cancer Author links open overlay panel

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Particuology 2024年第8期91卷 280-290页

作者： Yan Wang Feng Li Shuang Wang Jiaqi Meng Xiao Zhang Wei Wei State Key Laboratory of Biochemical engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China Key Laboratory of Biopharmaceutical Preparation and Delivery Chinese Academy of SciencesBeijing100190China School of Chemical engineering University of Chinese Academy of SciencesBeijing100049China

Immune checkpoint blockade(ICB)has emerged as a promising immunotherapeutic modality against cancer in the ***,only 10-30%of patients respond to ICB,primarily due to poor immunogenicity and insufficient T cell infiltration in solid ***,we presented an approach for high-performance cancer treatment using the programmed cell death protein-1 and programmed cell death ligand-1(PD-1/PD-L1)inhibitor(BMS-202)-loaded PEGylated graphene oxide(GPi).On the one hand,GPi dissociated tight junctions of vascular endothelial cells(VECs)in tumor,thus promoting the extravasation and intratumoral accumulation of liposomal doxorubicin(LipDox),which then effectively induced immunogenic cell death of tumor *** the other hand,GPi also stimulated VECs to upregulate the expression of cell-cell interaction molecules,such as intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1,which facilitated the infiltration of T cells in *** acting as a stimulator of VECs,GPi could exert responsive release of BMS-202 under the acidic tumor microenvironment and blockade PD-1/PD-L1 axis in ***,the alternating administration of GPi and LipDox effectively inhibited tumor growth in a 4T1 tumor model,providing a novel treatment mode for chemo-immunotherapy.

关键词： PEGylated graphene oxide Vascular endothelial cells Immune checkpoint blockade Immunogenic cell death Chemo-immunotherapy

Microneedle patch loaded with ferritin-nanocaged doxorubicin for locally targeted drug delivery and efficient skin cancer treatment

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Particuology 2024年第5期88卷 282-289页

作者： Feng Li Yuan Yang Hua Yue Shuang Wang Xiao Zhang Wei Wei State Key Laboratory of Biochemical engineering Institute of Process EngineeringChinese Academy of SciencesBeijing100190China Key Laboratory of Biopharmaceutical Preparation and Delivery Chinese Academy of SciencesBeijing100190China School of Chemical engineering University of Chinese Academy of SciencesBeijing100049China

Ferritin has emerged as a promising nanocarrier for delivering therapeutic agents to ***,the limited drug loading and the off-target impacts after systemic administration remain challenges for cancer treatment with ferritin-based ***,we develop a microneedle patch loaded with ferritin-nanocaged doxorubicin(DoxFe@Fn/MN)for skin cancer ***,doxorubicin(Dox)is encapsulated in ferritin(Fn)using an iron core-assisted strategy,which results in a 3.4-fold increase in Dox loading compared to the direct loading ***,a polyvinyl alcohol-based microneedle(MN)patch is used for the transdermal delivery of DoxFe@Fn,enabling targeted tumour accumulation of DoxFe@Fn and preventing off-target *** released DoxFe@Fn can bind to CD71 highly expressed on skin cancer cells,facilitating its *** a result,the DoxFe@Fn/MN therapy presents a robust antitumour effect in a melanoma tumour model,showing its potential as a promising therapeutic modality for skin cancer treatment.

关键词： Ferritin Microneedle Skin cancer Drug delivery

Classification of knowledge graph completeness measurement techniques

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Journal of Systems engineering and Electronics 2024年第1期35卷 154-162页

作者： ZHANG Ying XIAO Gang Institute of Systems engineering Academy of Military SciencesBeijing 100107China

At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and *** assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same ***,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge *** them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among *** this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness *** purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.

关键词： quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption