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transferable adversarial slow feature extraction network for few-shot quality prediction in coal-to-ethylene glycol process

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chinese Journal of chemical engineering 2024年第7期71卷 258-271页

作者： cheng Yang chao Jiang Guo Yu Jun Li cuimei Bo School of electrical engineering and control Science Nanjing Tech UniversityNanjing 211816China Department of Intelligent Manufacturing Nanjing Tech UniversityNanjing 210009China

In the coal-to-ethylene glycol(cteG)process,precisely estimating quality variables is crucial for process monitoring,optimization,and control.A significant challenge in this regard is relying on offline laboratory analysis to obtain these variables,which often incurs substantial monetary costs and significant time *** resulting few-shot learning scenarios present a hurdle to the efficient development of predictive *** address this issue,our study introduces the transferable adversarial slow feature extraction network(tASF-Net),an innovative approach designed specifically for few-shot quality prediction in the cteG ***-Net uniquely integrates the slowness principle with a deep Bayesian framework,effectively capturing the nonlinear and inertial characteristics of the cteG ***,the model employs a variable attention mechanism to identify quality-related input variables adaptively at each time step.A key strength of tASF-Net lies in its ability to navigate the complex measurement noise,outliers,and system interference typical in cteG *** learning strategy using a min-max game is adopted to improve its robustness and ability to model irregular industrial data accurately and ***,an incremental refining transfer learning framework is designed to further improve few-shot prediction performance achieved by transferring knowledge from the pretrained model on the source domain to the target *** effectiveness and superiority of tASF-Net have been empirically validated using a real-world cteG *** with some state-of-the-art methods,tASF-Net demonstrates exceptional capability in addressing the intricate challenges for few-shot quality prediction in the cteG process.

关键词： chemical process Neural networks Slowness principle transfer learning Prediction

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Grain-boundary segregation and grain growth in nanocrystalline substitutional solid solution alloys

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Journal of Materials Science & technology 2024年第1期168卷 239-249页

作者： Fawei tang chao Hou Hao Lu Zhi Zhao Xiaoyan Song Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China

A model for describing solute segregation at grain boundaries has been developed for substitutional solid solution alloys,which integrates multiple factors from atomic to microstructural scales.A concept of mo-lar Gibbs free energy of segregation was introduced to evaluate the segregating capability of the solute elements in a closed system,through which the influences of grain boundary structure,grain size,ma-terial composition,and external conditions were *** on the evaluation of various energy forms related to solute segregation and grain growth processes,the nature of the thermal stabilization of nanograin structures by solute segregation was disclosed.A criterion for the destabilization of nanostruc-tures,which is determined by the competition of the change rates between the molar Gibbs free energy of segregation and the total energy of grain boundaries with grain size,has been *** study provided guideline to achieve high-temperature stability of nanograin structures of solid solution alloys even for the weakly segregating nanocrystalline systems.

关键词： Substitutional solid solution Grain boundary segregation thermal stabilization Solute concentration Grain size

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Structural uncertainty quantification of Reynolds-Averaged Navier–Stokes closures for various shock-wave/boundary layer interaction flows

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chinese Journal of Aeronautics 2024年第3期37卷 34-48页

作者： Fanzhi ZeNG tianxin ZHANG Denggao tANG Jinping LI chao YAN School of Aeronautic Science and engineering Beihang UniversityBeijing 100191China School of Aeronautical engineering Air Force Engineering UniversityXi’an 710038China

Accurate prediction of Shock-Wave/Boundary Layer Interaction(SWBLI)flows has been a persistent challenge for linear eddy viscosity models.A major limitation lies in the isotropic representation of the Reynolds stress,as assumed under the Boussinesq *** studies have shown promise in improving the prediction capability for incompressible separation flows by perturbing the Reynolds-stress anisotropy ***,it remains uncertain whether this approach is effective for SWBLI flows,which involve compressibility and *** address this issue,this study systematically quantifies the structural uncertainty of the anisotropy for oblique SWBLI *** eigenspace perturbation method is applied to perturb the anisotropy tensor predicted by the Menter Shear–Stress transport(SSt)model and reveal the impacts of anisotropy on the prediction of quantities of interest,such as separation and reattachment positions,wall static pressure,skin friction,and heat *** results demonstrate the potential and reveal the challenges of eigenspace perturbation in improving the SSt ***,a detailed analysis of turbulent characteristics is performed to identify the source of *** findings indicate that eigenspace perturbation primarily affects turbulent shear stress,while the prediction error of the SSt model is more related to turbulent kinetic energy.

关键词： Shock-wave/boundary layer interaction(SWBLI) turbulence models Uncertainty analysis eigenspace perturbation Anisotropy

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comparison of combustion characteristics of tars Produced with tobacco Stem Biomass Gasification

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Journal of Renewable Materials 2024年第1期12卷 119-129页

作者： Bo chen Mingjun Wang Bo Liu chunping Lu Guohai Jia Yong chao chao Zhong School of Mechanical engineering Hunan Institute of EngineeringXiangtan411104China School of Automotive engineering Xiangtan Institute of TechnologyXiangtan411100China School of electrical and Information engineering Hunan Institute of EngineeringXiangtan411104China china Metallurgic Jingcheng(Xiangtan)Heavy Industry equipment co. Ltd.Xiangtan411100China Hunan Shuanghuan Fiber Molding Machinery co. Ltd.Xiangtan411100China

In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were *** result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.

关键词： tobacco stem tar gasifier combustion characteristics

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MicroeD as a powerful technique for the structure determination of complex porous materials

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chinese Journal of Structural chemistry 2024年第3期43卷 41-54页

作者： chao Ma cong Lin Jian Li State Key Laboratory of coordination chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing210023China Department of Applied Biology and chemical technology The Hong Kong Polytechnic UniversityKowloonHong Kong China

Porous materials have garnered significant attention in recent *** the intrinsic relationship between their structures and properties requires precise knowledge of their atomic ***-crystal X-ray diffraction(ScXRD)has traditionally been the primary method for elucidating such structures,but it demands large,high-quality crystals,often exceeding 5μm in *** growth of these crystals can be a time-consuming process,especially for one-and two-dimensional *** explore structures at the nanoscale,MicroeD(microcrystal electron diffraction(eD))offers unprecedented insights into the realm of *** revolutionary technique enables researchers to uncover intricate details within nanoscale structures,promising to reshape our fundamental understanding of *** this review,we delve into the applications of MicroeD in the study of various porous materials,including zeolites,metal-organic frameworks(MOFs),and covalent organic frameworks(cOFs).We emphasize the pivotal role of MicroeD in nanomaterial characterization,enabling precise crystallographic analysis and phase identification.

关键词： Atomic structure MicroeD Porous materials three-dimensional electron diffraction

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Dexamethasone implant in naive versus refractory patients with diabetic macular edema:a Meta-analysis

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International Journal of Ophthalmology(english edition) 2024年第10期17卷 1898-1904页

作者： Qian Xu chao Yang Jie Luan Department of Ophthalmology Zhongda HospitalSoutheast UniversityNanjing 210009Jiangsu ProvinceChina School of Medicine Southeast UniversityNanjing 210009Jiangsu ProvinceChina

AIM:to evaluate the efficacy and safety of the intravitreal dexamethasone implant in naive and refractory patients with diabetic macular edema(DMe).MetHODS:PubMed,embase,Web of Science,and Medline databases were *** main outcomes were best-corrected visual acuity(BcVA)and central retinal thickness(cRt).the secondary outcomes included mean number of injections,intraoperative or postoperative complications including intraocular pressure(IOP)elevation and ***:ten comparative studies involving a total of 1000 DMe eyes including 402 naive eyes and 598 refractory eyes were *** postoperative BcVA in the naive group was significantly better than in the refractory group[mean difference(MD)-0.11,95%confidence interval(cI)-0.17 to-0.05,P=0.0003;MD 8.69,95%cI 5.08 to 12.30,Ptionally,the naive group got greater improvement of BcVA change as well as more gains of BcVA letters than the refractory group[MD 7.71,95%cI 2.02 to 13.40,P=0.008;odds ratio(OR)2.99,95%cI 2.05 to 4.37,Pthe subgroup analysis revealed that the naive group had significantly higher BcVA gains of≥5,≥10,and≥15 letters compared to the refractory group(P=0.002,0.0001,0.003,respectively).No significant difference was detected between the two groups in either postoperative cRt(MD-22.36,95%cI-46.39 to 1.66,P=0.07)or the overall mean number of injections(MD-0.08,95%cI-0.38 to 0.22,P=0.61).Intraoperative and postoperative complications including the elevation of IOP(OR 0.47,95%cI 0.20 to 1.13,P=0.09)and cataract(OR 1.78,95%cI 0.97 to 3.24,P=0.06)showed no significant differences between the two groups during the follow-up ***:Intravitreal dexamethasone implants for DMe can improve anatomical and functional outcomes in both naive and refractory eyes and have a well-acceptable safety ***,naive eyes maintain better visual outcomes than refractory *** provides further evidence of better visual response when used for naive eyes as firstline t

关键词： diabetic macular edema dexamethasone implant refractory eyes systemic review

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Flavor mixing and solution structures in Dyson–Schwinger equations for a two-flavor system

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communications in theoretical Physics 2024年第10期76卷 64-77页

作者： Xue-ao chao Yu-xin Liu Department of Physics and State Key Laboratory of Nuclear Physics and technology Peking University collaborative Innovation center of Quantum Matter center for High energy Physics Peking University

We solved the Dyson–Schwinger(DS) equations for a two-flavor system with symmetry to study its flavor mixing effects. Initially, we employed the point interaction model and bare vertex approximation to reveal the structure of the solutions. Using the point interaction model, the DS equations can be solved analytically, and we found that these solutions can be classified into three groups, each forming an ellipse. these solutions exhibit SO(2) symmetry, while the original SU(2)symmetry at the Lagrangian level is dynamically broken to SO(2), corresponding to the emergence of flavor mixing effects. However, this flavor mixing effect does not manifest in the final physical *** utilizing the system's SO(2) symmetry, we can diagonalize the propagators of the DS equations,eliminating the flavor mixing effect but causing the originally degenerate masses at the Lagrangian level to split. these mass eigenstates have identical quantum numbers but different masses. If we can correspond these to quark particles of different generations, we can explain why the three generations of quarks have different masses and obtain the corresponding quark mass spectrum. Finally, we provide the corresponding numerical results using a more realistic interaction model.

关键词： dynamic symmetry breaking Dyson-Schwinger equation flavor change mass splitting

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Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

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Petroleum 2024年第1期10卷 150-164页

作者： Leonardo Goliatt c.M.Saporetti L.c.Oliveira e.Pereira Department of computational and Applied Mechanics Federal University of Juiz de Fora Department of computational Modeling Polytechnic Institute Rio de Janeiro State University Petrobras Department of Stratigraphy and Paleontology Rio de Janeiro State University

Rock samples' tOc content is the best indicator of the organic matter in source rocks. the origin rock samples' analysis is used to calculate it manually by specialists. this method requires time and resources because it relies on samples from many well intervals in source rocks. therefore, research has been done to aid this effort. Machine learning algorithms can estimate total organic carbon instead of well logs and stratigraphic studies. In light of these efforts, the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and precision. Genetic algorithms, differential evolution, particle swarm optimization, grey wolf optimization, artificial bee colony, and evolution strategies were used to improve machine learning models to predict tOc. the six metaheuristics were integrated into four machine learning methods: extreme learning machine, elastic net linear model, linear support vector regression, and multivariate adaptive regression splines. core samples from the YuDong-Nan shale gas field, located in the Sichuan basin, were used to evaluate the hybrid strategy. the findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict tOc. the results show that, independent of the metaheuristic used to guide the model selection, optimized extreme learning machines attained the best performance scores according to six metrics. Such hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： total organic carbon Hybrid models Automated machine learning evolutionary algorithms Geology

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correlation between carbon emissions,fuel consumption of vehicles and speed limit on expressway

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Journal of traffic and transportation engineering(english edition) 2024年第4期11卷 631-642页

作者： chao Gao Jinliang Xu Miao Jia Zhenhua Sun School of Highway Chang'an UniversityXi'an 710064China Shaoxing communications Investment Group co. Ltd.Shaoxing 312000China

this paper aimed to investigate the correlation between carbon emissions,fuel consumption,and speed limit.A theoretical model was derived based on the energy conservation law,which expresses the relationship between vehicle's fuel consumption and ***,a total of 40 sets of fuel consumption data were collected through field tests to verify the accuracy of the theoretical model at different speeds and different road longitudinal slope *** fuel consumption was then converted to carbon emissions according to the carbon emission factors specified by Intergovernmental Panel on climate change(IPcc).In the field experiment,two types of cars and trucks,which are most common on the expressways in china,were ***,the travel speed under different posted speed limits was obtained through the previously established model,and the carbon emission changes of different vehicle types at different limited speeds are *** results show that the speed limit has a significant impact on fuel consumption and carbon *** the speed limit increased from 80 to 120 km/h,average vehicle speeds increased about 21%-27%,and fuel consumption and carbon emissions increased from approximately 33%-38%.Another interesting result was that the vehicle's fuel consumption and carbon emissions are only affected by *** results of the study explore the effect of speed limits on carbon emissions and provide evidence for road managers to set reasonable speed limits.

关键词： Vehicle carbon emission Vehicle fuel consumption Posted speed limit Average speed Road longitudinal slope

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efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at extremes 2024年第4期9卷 29-39页

作者： L.Xu t.W.Huang K.Jiang c.N.Wu H.Peng P.c.hen R.Li H.B.Zhuo c.t.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

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