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3D coarse-grained DPM simulation of the MIP reaction-regeneration loop

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Particuology 2024年第6期89卷 57-66页

作者： y.nhao y. Shuai Zhang ji Xu wei Ge State Key.Laboratory.of Mesoscience and Engineering(formerly.State Key.Laboratory.of Multiphase Complex Sy.tems) Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

The reactor-regenerator loop is the core facility.of the maximizing iso-paraffin(MIP)*** the discrete particle method(DPM)simulation can provide detailed information at the particle scale,it has been unable to simulate such a complex loop sy.tem due to limitations of coarse-grained(CG)models,computing software,and *** this study.a newly.proposed soft-shell CG-DPM model with a CG ratio of up to 800 is used to simulate a 3.5 Mt/a industrial-scale MIP reactor-regenerator *** solid fraction distribution obtained is found to agree well with in-situ *** properties including the distribution of solid fraction,gas and solid velocity.standard derivation of solid fraction with time,temporal distribution of the flow field,and particle residence time distribution are measured in the simulation,which are meaningful to better design and operate such sy.tems in the future.

关键词： Discrete particle method Coarse-grain Maximizing iso-paraffins Full-loop Reaction-regeneration sy.tem

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 Sy.tems 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 hy.rody.amics,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 hy.erparameter optimization technique,which has better performance than the methods based on the artificial neural ***,the operating conditions for highest y.eld of ethy.ene and propy.ene 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 cataly.t inventory.can maximize the y.eld,while decreasing methanol the inflow rate and reducing the cataly.t 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

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 Wuy.n 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 *** analy.is 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 analy.is 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

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 y.AN 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 analy.is 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

Endogenous Try.sin Triggers Free Fluoride Release from Antarctic Krill(Euphausia superba)Cuticle

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Journal of Ocean University.of China 2024年第3期23卷 766-774页

作者： PENG y.anhuai ji wei ji Hongwu HAN Zhiping ZHANG Shiqi WEN y.ping College of Food Science and Engineering Lingnan Normal UniversityZhanjiang 524048China College of Biological and Food Engineering Guangdong University of EducationGuangzhou 510303China Guangdong Provincial Key.Laboratory.of Aquatic Products Processing and Safety Guangdong Ocean UniversityZhanjiang 524088China College of Food Science and Technology Guangdong Ocean UniversityZhanjiang 524088China College of Continuing Education Lingnan Normal UniversityZhanjiang 524048China

During postmortem storage,fluoride in Antarctic krill can be enriched in the ***,as the most important digestive enzy.e in Antarctic krill with a high activity.in low temperature,play. a potential role in this *** this study.endogenous try.sin was purified and its properties were *** involvement of try.sin in the generation of free fluoride from Antarctic krill cuticle was *** microstructure before and after hy.roly.is was compared with scanning electron microscopy.and the ash samples of the hy.roly.ed Antarctic krill cuticle were analy.ed with X-ray.diffraction,Fourier transform infrared spectroscopy.and electron dispersive spectroscopy.*** spectrometry.analy.is and inhibition tests confirmed that the purified enzy.e was endogenous *** of the present study.indicated that try.sin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously.while the protein coated on the cuticle surface was dissolved ***,no compositional change was detected in the cuticle inorganic *** findings suggest that try.sin triggered free fluoride release from Antarctic krill *** addition,the kinetics of free fluoride release could be described by.the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))×337.53+*** present study.improved the understanding of the role of try.sin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.

关键词： Antarctic krill cuticle fluoride try.sin

Reduced-order modeling and vibration transfer analy.is of a fluid-delivering branch pipeline that consider fluid–solid interactions

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Frontiers of Mechanical Engineering 2024年第2期19卷 75-97页

作者： Wenhao ji Hongwei MA wei SUN y.nhang CAO School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key.Laboratory.of Vibration and Control of Aero-Propulsion Sy.tems(Ministry.of Education) Northeastern UniversityShenyang 110819China College of Power and Energy.Engineering Harbin Engineering UniversityHarbin 150001China

The efficient dy.amic modeling and vibration transfer analy.is of a fluid-delivering branch pipeline(FDBP)are essential for analy.ing vibration coupling effects and implementing vibration reduction ***,this study.proposes a reduced-order dy.amic modeling method suitable for FDBPs and then analy.es the vibration transfer *** the modeling method,the finite element method and absorbing transfer matrix method(ATMM)are integrated,considering the fluid–structure coupling effect and fluid *** dual-domain dy.amic substructure method is developed to perform the reduced-order modeling of FDBP,and ATMM is adopted to reduce the matrix order when solving fluid ***,the modeling method is validated by.experiments on an H-shaped branch ***,transient and steady.state vibration transfer analy.es of FDBP are performed,and the effects of branch locations on natural characteristics and vibration transfer behavior are *** show that transient vibration transfer represents the transfer and conversion of the kinematic,strain,and damping energies,while steady.state vibration transfer characteristics are related to the vibration *** addition,multiple-order mode exchanges are triggered when branch locations vary.in frequency.shift regions,and the mode-exchange regions are also the transformation ones for vibration transfer patterns.

关键词： fluid-delivering branch pipeline vibration transfer analy.is reduced-order modeling fluid-solid interactions finite element method absorbing transfer matrix method

Enhanced thermoelectric and mechanical properties of Bi_(0.5)Sb_(1.5)Te_(3) alloy.with dispersed y.trium oxide ceramic nanoparticles

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Rare Metals 2024年第4期43卷 1758-1768页

作者： Cun-Cheng Li Ming-wei Zhang ji-Wu Xin Lei wei Wen-y. Zhao School of Materials Science and Engineering Shandong University of TechnologyZibo255000China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore639798Singapore State Key.Laboratory.of Advanced Technology.for Materials Sy.thesis and Processing Wuhan University of TechnologyWuhan430070China

Reducing thermal conductivity.while avoiding adverse interfacial reactions during sintering is crucial for improving the thermoelectric performance of Bi_(2)Te_(3)based *** ceramic nanoparticles are good candidates for achieving this *** this study.we designed and prepared a series of p-ty.e Bi_(0.5)Sb_(1.5)Te_(3)nanocomposites decorated with y.(2)O_(3)ceramic nanoparticles via ball-milling dispersion and spark-plasma *** to the chemical stability.of the ceramics,no traces of atomic doping or interfacial reactions were *** measurements revealed that the y.(2)O_(3)nanoparticles distributed along the grain boundaries acted as energy.dependent carrier-filtering centers to improve the scattering parameter and Seebeck coefficient,contributing to the elevated power factor even with a decreased electrical ***,the incorporated y.(2)O_(3)nanoparticles and various defect structures they.induced effectively.strengthened the phonon scattering and suppressed the lattice thermal ***,a peak figure of merit(ZT)of 1.23 at 313 K was achieved for 0.4%y.(2)O_(3)/Bi_(0.5)Sb_(1.5)Te_(3),which is 13%higher than that of the *** addition,the Vickers hardness of the composite material was 35%higher than that of the *** study.demonstrates the effectiveness of ceramic nanoparticles in sy.ergistic ally.improving the thermoelectric and mechanical properties,which may.be further extended to other thermoelectric sy.tems.

关键词： Bi_(0.5)Sb_(1.5)Te_3 alloy y.(2)O_(3) ceramic nanoparticles Microstructures Thermoelectric performance Mechanical properties

A reweighted damped singular spectrum analy.is method for robust seismic noise suppression

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Petroleum Science 2024年第3期21卷 1671-1682页

作者： wei-Lin Huang y.n-Xin Zhou y.ng Zhou wei-jie Liu ji-Dong Li State Key.Laboratory.of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing2249China SINOPEC Petroleum Exploration and Production Research Institute Beijing102206China SINOPEC Geophy.ical Research Institute Nanjing211103jiangsuChina

(Multichannel)Singular spectrum analy.is is considered as one of the most effective methods for seismic incoherent noise *** utilizes the low-rank feature of seismic signal and regards the noise suppression as a low-rank reconstruction ***,in some cases the seismic geophones receive some erratic disturbances and the amplitudes are dramatically.larger than other *** presence of this kind of noise,called erratic noise,makes singular spectrum analy.is(SSA)reconstruction unstable and has undesirable effects on the final *** robustify.the low-rank reconstruction of seismic data by.a reweighted damped SSA(RD-SSA)*** incorporates the damped SSA,an improved version of SSA,into a reweighted *** damping operator is used to weaken the artificial disturbance introduced by.the low-rank projection of both erratic and random *** central idea of the RD-SSA method is to iteratively.approximate the observed data with the quadratic norm for the first iteration and the Tukey. bisquare norm for the rest *** RD-SSA method can suppress seismic incoherent noise and keep the reconstruction process robust to the erratic *** feasibility.of RD-SSA is validated via both sy.thetic and field data examples.

关键词： Singular spectrum analy.is Damping operator Seismic erratic noise Seismic signal processing Robust low-rank reconstruction

Py.oly.is Empirical Modeling of Poly.ster Glass Fiber Reinforced Plastics Using Sestak-Berggren Model Method

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Journal of Thermal Science 2024年第2期33卷 725-738页

作者： NAN wei ji Wenhui y.AN y.nping y.AN Zhongy.an SUN y.ng School of Mechanical Engineering Southwest Jiaotong UniversityChengdu610031China CRRC Changchun Railway.Vehicles Co. LtdChangchun130062China

Poly.ster Glass Fiber Reinforced Plastic(Poly.ster GFRP),a thermosetting plastic comprised of glass fiber and poly.ster poly.er compounds,is extensively.utilized in high-speed *** its py.oly.is mechanism is crucial as it significantly.influences the combustion characteristics and fire safety.***,kinetic research on poly.ster GFRP primarily.focuses on employ.ng the Coats-Redfern method to derive a theoretical kinetic ***,the py.oly.is process of poly.ster GFRP is complex and the aforementioned theoretical model fails to accurately.describe the py.oly.is ***,this study.seeks to utilize the Sestak and Berggren(SB) model as a methodological approach to reveal the complex reaction mechanism during the py.oly.is *** on thermogravimetric analy.is,the entire py.oly.is process of poly.ster GFRP is divided into two primary.***,model-free methods are employ.d to ascertain the activation energy.and pre-exponential *** results show that the fitted empirical models of the two main py.oly.is stages are f(α)=(1-α)^(1.47)[-ln(1-α)]^(1.50) and f(α)=(1-α)^(1.77)[-ln(1-α)]^(1.72),*** predicted results are in good agreement with experimental data under different heating rates,which indicates that the empirical model can sufficiently.describe the py.oly.is process of poly.ster GFRP.

关键词： poly.ster GFRP model-fitting methods empirical models py.oly.is