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Numerical investigation and modeling of sweep effects on inlet flow field of axial compressor cascades

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chinese Journal of Aeronautics 2024年第2期37卷 296-308页

作者： Jiancheng ZHANG Donghai JIN Xingmin gui School of Energy and Power Engineering Beihang UniversityBeijing 100191China Jiangxi Research Institue of Beihang University Nanchang 330096China

Swept blades are widely utilized in transonic compressors/fans and provide high load,high through-flow,high efficiency,and adequate stall ***,there is limited quantitative research on the mechanism of the effect of swept blades on the flow field,resulting in a lack of direct quantitative guidance for the design and analysis of swept blades in fans/*** better understand this mechanism,this study employs a reduced-dimensional force equilibrium method to analyze more than 1500 swept cascades *** verify that circumferential fluctuation terms are responsible for inducing radial migration in the inlet airflow field of the swept blade,resulting in variations in the incidence angle and consequently leading to changes in the characteristics of the swept ***,a combination of simple functions and machine learning is utilized to model the circumferential fluctuation terms and quantify the sweep *** prediction accuracy of the model is high,with coefficient of determination greater than 0.95 on the test *** the model is applied in a meridional flow analysis program,the calculation accuracy of the program for the incidence angle is improved by 0.4°and 0.6°at the design and off-design conditions respectively,compensating for the program’s original ***,the model can also provide quantitative guidance for the design of swept blades,thereby reducing the number of design iterations and improving design efficiency.

关键词： Turbomachinery Sweep aerodynamics Quasi-3D method Incidence angle circumferential fluctuation Machine learning

Study on Effectiveness of Solitary-Wave-like Form Based on Overtopping Data from Irregular Wave Tests

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china Ocean Engineering 2024年第4期38卷 701-710页

作者： lI Xiao-liang Huang gui-biao School of Naval Architecture&Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China

The previous study conducted by li(2022)demonstrates that the Goda graph can be adequately represented by a solitary-wave-like form across the entire range of relative water depth,with the exception of the extremely shallow ***,it remains uncertain whether this form is equally effective when applied to test data generated by irregular waves,as the Goda graph was initially developed based on overtopping data from regular wave ***,it is unclear whether this form is suitable for formulating overtopping discharge at composite vertical *** order to address these questions,a 2D overtopping experiment was conducted,incorporating both simple and composite types of vertical walls,with various relative water depths across the entire range,excluding the extremely shallow zone.A novel analysis procedure was developed,which proved to be highly productive and can be considered a general method for data ***,the study yielded two conclusions:(1)the solitary-wave-like form is remarkably effective in formulating overtopping test data generated by irregular waves,regardless of whether the vertical wall is simple or composite,and(2)the resulting formulas exhibit definitely better performance compared with existing formulas.

关键词： solitary-wave-like form overtopping discharge overtopping formula vertical wall

Robust Feedback Set Stabilization of logic Networks with State-Dependent Uncertain Switching and control constraints

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Journal of Systems Science & complexity 2024年第2期37卷 629-646页

作者： DAI chaoqun GUO Yuqian gui Weihua School of Automation Central South UniversityChangsha 410083China

This study investigates the robust feedback set stabilization of switched logic control networks(SlcNs)with state-dependent uncertain switching and control ***,based on the properties of the semi-tensor product of matrices and the vector representation of logic,an SlcN with state-dependent uncertain switching and control constraints is expressed in algebraic ***,an input transformation and a switching model are constructed to transfer the original SlcN into one with a free control input and arbitrary *** equivalence between the set stabilizability of the original SlcN and that of the resulting SlcN is *** on such equivalence,the authors propose a necessary and sufficient condition for robust feedback set ***,an example is presented to demonstrate the application of the results obtained.

关键词： Input transformation robust control invariant subset robust feedback set stabilizability semi-tensor product state-dependent constraints switched logic control network

Ultra-large aluminum shape casting:Opportunities and challenges

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china Foundry 2024年第5期21卷 397-408页

作者： Qi-gui Wang Andy Wang Jason coryell Advanced Materials Technology&Virtualization GM Global Technical CenterWarrenMI USA

Ultra-large aluminum shape castings have been increasingly used in automotive vehicles,particularly in electric vehicles for light-weighting and vehicle manufacturing cost *** most of them are structural components subject to both quasi-static,dynamic and cyclic loading,the quality and quantifiable performance of the ultra-large aluminum shape castings is critical to their success in both design and *** paper briefly reviews some application examples of ultra-large aluminum castings in automotive industry and outlines their advantages and *** affecting quality,microstructure and mechanical properties of ultra-large aluminum castings are evaluated and discussed as aluminum shape casting processing is very complex and often involves many competing mechanisms,multi-physics phenomena,and potentially large uncertainties that significantly influence the casting quality and *** analysis and mechanical property assessment of an ultra-large aluminum shape casting are *** are highlighted and suggestions are made for robust design and manufacturing of ultra-large aluminum castings.

关键词： ultra-large castings aluminum light-weighting quality microstructure materials properties

Enhanced Sensing Mechanism Based on Shifting an Exceptional Point

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Research 2024年第3期6卷 285-292页

作者： Xuan Mao Guo-Qing Qin Hao Zhang Bo-Yang Wang Dan long gui-Qin li gui-lu long Department of Physics State Key Laboratory of Low-Dimensional Quantum PhysicsTsinghua UniversityBeijing 100084China Beijing Institute of Radio Measurement The Second Academy of China Aerospace Science and Industry Corporation(CASIC)Beijing 100854China Purple Mountain laboratories Nanjing 21111China Frontier Science center for Quantum Information Beijing 100084China Beijing Academy of Quantum Information Sciences Beijing 100193China

Non-Hermitian systems associated with exceptional points (EPs) are expected to demonstrate a giant response enhancement for various sensors. The widely investigated enhancement mechanism based on diverging from an EP should destroy the EP and further limits its applications for multiple sensing scenarios in a time sequence. To break the above limit, here, we proposed a new enhanced sensing mechanism based on shifting an EP. Different from the mechanism of diverging from an EP, our scheme is an EP nondemolition and the giant enhancement of response is acquired by a slight shift of the EP along the parameter axis induced by perturbation. The new sensing mechanism can promise the most effective response enhancement for all sensors in the case of multiple sensing in a time sequence. To verify our sensing mechanism, we construct a mass sensor and a gyroscope with concrete physical implementations. Our work will deepen the understanding of EP-based sensing and inspire designing various high-sensitivity sensors in different physical systems.

关键词： mechanism shifting exceptional

Bianjing Spectacle: Soundscapes of Bianjing and Identities in Song Dynasty literature

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Frontiers of literary Studies in china-Selected Publications from chinese Universities 2024年第1期18卷 77-102页

作者： lI gui School of Humanities Shanghai Normal UniversityShanghai 200234China

By closely examining the literary works of the Song Dynasty,such as prose,poetry,rhyme-prose,lyrics,notes,and miscellaneous theses,this paper combines historical and literary evidence to rediscover the 13 types of soundscapes and their corresponding spaces in the Bianjing city,the capital of the Northern Song Dynasty,and it reveals the causes and historical-cultural significance of these *** on the key issues of soundscapes,this paper analyzes the sound spaces,identities,discourses,and literary achievements depicted in the writings about *** argues that the“Bianjing Spectacle”of vendors’cries described by the Southern Song people can be used as a summary of the soundscape characteristics of ***,it interprets the special silence,crying,and the absence of the sounds of production from an aesthetic *** rediscovering,analyzing,and interpreting the soundscapes of Bianjing,this paper reveals significant differences between the Tang and Song dynasties at the sound level and differentiates various“auditory communities.”It thereby demonstrates the portrayal of Bianjing in Song literature,addresses theoretical hot topics in literature and geography,and builds on Marx’s arguments to propose that a thorough understanding of history,the world,and ourselves requires an in depth study of the soundscapes in literature.

关键词： Song literature Bianjing in the Northern Song Dynasty soundscapes identities transformation during the Tang and Song dynasties

A three-dimensional inverse method based on moving no-slip boundary for profiled end wall design

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chinese Journal of Aeronautics 2024年第10期37卷 221-233页

作者： Hanwen GUO Donghai JIN Jiancheng ZHANG Xingmin gui School of Energy and Power Engineering Beihang UniversityBeijing 100191China Jiangxi Research Institute of Beihang University Nanchang 330096China

How to utilize existing flow control mechanisms to make profiled end wall design more flexible,efficient,and physical is a meaningful *** study presents a three-dimensional inverse method for profiled end wall design to achieve the application of flow control *** predetermined pressure distribution on the end wall is reached by modifying the end wall geometry during flow field calculation.A motion velocity model is derived from the normal momentum equation of the moving no-slip boundary to modify the end wall geometry.A Reynolds-Averaged Navier-Stokes(RANS)solver based on the Semi-Implicit Method for Pressure linked Equations(SIMPlE)algorithm is adopted to simulate the flow *** on the mechanism understanding obtained through numerical optimization results,this study adopts the inverse method to redesign an optimized end wall in a compressor *** results indicate that the redesigned end wall exhibits better loss reduction,reducing the overall total pressure loss by 5.5%,whereas the optimized end wall reduces it by 3%.The inverse method allows the imposition of desired influences on the end wall flow without constructing a database,making it highly flexible,efficient,and physical.

关键词： compressor Flow control corner separation Profiled end wall Inverse method

Electrocatalytic coupling of anodic nitrogen oxidation and cathodic nitrate reduction for ammonia synthesis from air and water

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Nano Research 2024年第9期17卷 7824-7829页

作者： Aijing Ma Jianzhou gui Yanmei Huang Yifu Yu State Key laboratory of Separation Membranes and Membrane Processes Tianjin Key Laboratory of Green Chemical Technology and Process EngineeringSchool of Chemical Engineering and TechnologyTiangong UniversityTianjin 300387China Institute of Molecular Plus School of Chemical EngineeringTianjin UniversityTianjin 300072China

Ammonia plays a vital role in present agriculture and industry,and is also regarded as a next-generation clean energy *** development of electrocatalysis raises an opportunity to make ammonia synthesis compatible with intermittent and variable renewable energy sources such as solar and wind ***,the direct ammonia electrosynthesis from N_(2)reduction is still challenging due to the much easier hydrogen evolution competition *** this perspective,we propose a novel strategy for ammonia electrosynthesis from air and water based on the coupling of anodic nitrogen oxidation and cathodic nitrate *** methods for breaking the bottlenecks of anodic nitrogen oxidation and cathodic nitrate reduction are discussed *** that,key issues that need to be considered in the coupled system are proposed for the application of this strategy.

关键词： electrocatalysis nitrogen oxidation nitrate reduction nitrogen fixation ammonia synthesis

Synthesis of a High-Efficiency Demulsifier and Study on Optimal Demulsification conditions

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china Petroleum Processing & Petrochemical Technology 2024年第1期26卷 107-115页

作者： Zhu Shuai Zhang YingYu gui Xia college of chemical Engineering Nanjing Tech University30 Puzhunan RoadNanjing 211816China

Oil and water separation has always been a top priority in the oil *** this study,a series of hyperbranched fluorinated polyamine-amine polymers(HFPA1-5)were synthesized directly using an improved“one-pot method.”The highly active fluorinated p-trifluoromethylaniline was used as the core raw material,while diethylenetriamine and methyl acrylate were used as the chain segment.A hyperbranched fluorine-containing polyamine-amine demulsifier(NHFPA6)was obtained through nano-grafting copolymerization of *** enhance the demulsification and dehydration performance,the copolymerized HFPA6 was modified and ***,the effects of the combination ratio,demulsifier concentration,demulsification time,and demulsification temperature on the demulsification effect were *** results revealed that a combination ratio of DE-401:NHFPA6=1:1,a demulsification temperature of 50℃,a demulsification time of 60 min,and a demulsifier concentration of 150 mg/l yielded a dehydration rate as high as 99.80%.A response surface optimization design of demulsification conditions was *** model verified that the optimal demulsification conditions were 50℃,300 mg/l,and 90 ***,considering the economic benefits of factories,it is more favorable to select demulsification conditions with a shorter time and lower concentration when the dehydration standard is ***,the demulsification conditions were selected as 50℃,150 mg/l,and 60 *** to existing demulsifiers,the demulsifier developed in this study exhibits a lower demulsification temperature and higher demulsification efficiency.

关键词： hyperbranched fluorinated polyamine-amine nano-SiO_(2)