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Almost global smooth solutions of the 3D quasilinear Klein-Gordon equations on the product space R×T

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Science China Mathematics 2024年

作者： Jun Li fei tao Huicheng Yin Department of Mathematics Nanjing University School of Mathematical Sciences and Mathematical Institute Nanjing Normal University

In this paper, for the 3D quadratic nonlinear Klein-Gordon equation on the product space R2× T,we focus on the lower bound of the lifespan of the smooth solution with slowly decaying initial data. When the size of initial data is bounded by ε0> 0, it is shown that a smooth solution exists up to the time ec0/ε0～2 with ε0being sufficiently small and c0> 0 being some suitable constant. Note that the solution of the corresponding 3D linear homogeneous Klein-Gordon equation on R2× T only admits the optimal time-decay rate（1 + t）-1,from which we generally derive the lifespan of the nonlinear Klein-Gordon equation up to ec0/ε0rather than the more precise ec0/ε0～2 here.

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A digital twin-enhanced collaborative maintenance paradigm for aero-engine fleet

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Frontiers of Engineering Management 2024年第2期11卷 356-361页

作者： Jiawei REN Ying CHENG Yingfeng ZHANG fei tao School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100083China School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China Digital Twin International Research Center International Research Institute for Multidisciplinary SciencesBeihang UniversityBeijing 100083China

Maintenance of aero-engine fleets is crucial for the efficiency,safety,and reliability of the aviation industry.With the increasing demand for air transportation,maintaining high-performing aero-engines has become significant.Collaborative maintenance,specifically targeting aero-engine fleets,involves the coordination of multiple tasks and resources to enhance management efficiency and reduce costs.Digital Twin(DT)technology provides essential technical support for the intelligent operation and maintenance of aero-engine fleets.DT maps physical object properties to the virtual world,creating high-fidelity,dynamic models.However,DT-enhanced collaborative maintenance faces various challenges,including the construction of complex system-layer DT models,management of massive integrated DT data,and the development of fusion mechanisms and decision-making methods for DT data and models.Overcoming these challenges will allow the aviation industry to optimize aero-engine fleet maintenance,ensuring safety,efficiency,and cost-effectiveness while meeting the growing demand for air transportation.

关键词： aero-engine fleet collaborative maintenance Digital Twin(DT) complex system

makeTwin:A reference architecture for digital twin software platform

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Chinese Journal of Aeronautics 2024年第1期37卷 1-18页

作者： fei tao Xuemin SUN Jiangfeng CHENG Yonghuai ZHU Weiran LIU Yong WANG Hui XU Tianliang HU Xiaojun LIU Tingyu LIU Zheng SUN Jun XU Jinsong BAO Feng XIANG Xiaohui JIN Digital Twin International Research Center International Research Institute for Multidisciplinary ScienceBeihang UniversityBeijing 100191China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Institute of Advanced Manufacturing and Intelligent Technology Beijing University of TechnologyBeijing 100124China RIAMB(Beijing)Technology Development Co Ltd(R.T.D.)Beijing 100120China School of Mechanical Engineering Shandong UniversityJinan 250061China School of Mechanical Engineering Southeast UniversityNanjing 211189China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710049China College of Mechanical Engineering Donghua UniversityShanghai 201620China School of Machinery and Automation Wuhan University of Science and TechnologyWuhan 430081China Beijing Aero-top Hi-tech Co LtdBeijing 100176China

Digital twin is currently undergoing a significant transformation from the conceptual and theoretical research phase to the implementation and application phase.However,a universally adaptable research and development platform for digital twin is critically needed to meet the development requirements.Specifically,a publicly accessible simulation,testing,and validation platform which can support digital twin model building,data processing,algorithm design,configuration,etc.,is urgently required for researchers.Furthermore,for developers from the industry,a lowcode development platform that can offer a customizable suite of functions such as model creation,data management,protocol configuration,and visualization is urgently needed.Meanwhile,for enterprise users,there is a lack of an application management platform that can be configured and migrated for various application scenarios,functions,and modes.Therefore,based on the system research of digital twin theories and key technologies by the authors(such as the five-dimension digital twin model,digital twin modeling and digital twin data theory,digital twin standards,and so on),a digital twin software platform reference architecture,namely make Twin,is proposed and designed,as well as its ten core functions.The workflow of the make Twin and the interaction mechanisms among its core functions are described.Finally,a digital twin application system for a chemical fiber textile shop floor(CFTS)which was developed according to make Twin,is introduced,which validates the proposed reference architecture.

关键词： Digital twin Digital twin software platform Industrial software makeTwin Reference architecture

GLOBAL CLASSICAL SOLUTIONS OF SEMILINEAR WAVE EQUATIONS ON R^(3)×T WITH CUBIC NONLINEARITIES

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Acta Mathematica Scientia 2024年第1期44卷 115-128页

作者：陶飞 School of Science Nanjing University of Posts and TelecommunicationsNanjing210023China

In this paper,we establish global classical solutions of semilinear wave equations with small compact supported initial data posed on the product space R^(3)×T.The semilinear nonlinearity is assumed to be of the cubic form.The main ingredient here is the establishment of the L^(2)-L^(∞)decay estimates and the energy estimates for the linear problem,which are adapted to the wave equation on the product space.The proof is based on the Fourier mode decomposition of the solution with respect to the periodic direction,the scaling technique,and the combination of the decay estimates and the energy estimates.

关键词： semilinear wave equation product space decay estimate energy estimate global solution

Harnessing Interactional Sensory Genes for Rationally Reprogramming Chaotic Metabolism

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Research 2023年第3期2022卷 295-308页

作者： Chunlin Tan Ping Xu fei tao State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciencesand School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghaiChina

Rationally controlling cellular metabolism is of great importance but challenging owing to its highly complex and chaotic nature.Natural existing sensory proteins like histidine kinases(HKs)are understood as“sensitive nodes”of biological networks that can trigger disruptive metabolic reprogramming(MRP)upon perceiving environmental fluctuation.Here,the“sensitive node”genes were adopted to devise a global MRP platform consisting of a CRISPR interference-mediated dual-gene combinational knockdown toolbox and survivorship-based metabolic interaction decoding algorithm.The platform allows users to decode the interfering effects of n×n gene pairs while only requiring the synthesis of n pairs of primers.A total of 35 HK genes and 24 glycine metabolic genes were selected as the targets to determine the effectiveness of our platform in a Vibrio sp.FA2.The platform was applied to decode the interfering impact of HKs on antibiotic resistance in strain FA2.A pattern of combined knockdown of HK genes(sasA_8 and 04288)was demonstrated to be capable of reducing antibiotic resistance of Vibrio by 108-fold.Patterns of combined knockdown of glycine pathway genes(e.g.,gcvT and ltaE)and several HK genes(e.g.,cpxA and btsS)were also revealed to increase glycine production.Our platform may enable an efficient and rational approach for global MRP based on the elucidation of high-order gene interactions.A web-based 1-stop service(https://***)is also provided to simplify the implementation of this smart strategy in a broad range of cells.

关键词： metabolism Rational programming

Production of N-acetylglucosamine with Vibrio alginolyticus FA2,an emerging platform for economical unsterile open fermentation

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Synthetic and Systems Biotechnology 2023年第3期8卷 546-554页

作者： Yuan Peng Ping Xu fei tao State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciencesand School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghaiPeople’s Republic of China

Members of the Vibrionaceae family are predominantly fast-growing and halophilic microorganisms that have captured the attention of researchers owing to their potential applications in rapid biotechnology.Among them,Vibrio alginolyticus FA2 is a particularly noteworthy halophilic bacterium that exhibits superior growth capability.It has the potential to serve as a biotechnological platform for sustainable and eco-friendly open fermentation with seawater.To evaluate this hypothesis,we integrated the N-acetylglucosamine(GlcNAc)pathway into V.alginolyticus FA2.Seven nag genes were knocked out to obstruct the utilization of GlcNAc,and then 16 exogenous gna1s co-expressing with EcglmS were introduced to strengthen the flux of GlcNAc pathway,respectively.To further enhance GlcNAc production,we fine-tuned promoter strength of the two genes and inactivated two genes alsS and alsD to prevent the production of acetoin.Furthermore,unsterile open fermentation was carried out using simulated seawater and a chemically defined medium,resulting in the production of 9.2 g/L GlcNAc in 14 h.This is the first report for de-novo synthesizing GlcNAc with a Vibrio strain,facilitated by an unsterile open fermentation process employing seawater as a substitute for fresh water.This development establishes a basis for production of diverse valuable chemicals using Vibrio strains and provides insights into biomanufacture.

关键词： Vibrio Open fermentation Metabolic engineering N-acetylglucosamine

Bilateral iridocorneal endothelial syndrome-Chandler’s syndrome:a case report and literature review

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International Journal of Ophthalmology(English edition) 2024年第4期17卷 773-776页

作者： Xiao-Hua Pan Yu-fei tao Ming-Min Yang Xiao-Li Shen Jiao Si Ming Li Ning Fan Shenzhen Eye Hospital Jinan UniversityShenzhen 518040Guangdong ProvinceChina

Dear Editor,I ridocorneal endothelial syndrome(ICE)is a rare ocular disease first proposed by Eagle et al[1]in 1979.It is mainly characterized by corneal endothelial abnormalities,accompanied by iris atrophy,iris pigmented nodules and peripheral anterior synechiae.ICE syndrome is typically unilateral,and classified into three clinical variants based on the changes of the cornea and iris,including progressive iris atrophy,Chandler’s syndrome,and Cogan-Reese syndrome.

关键词： corneal atrophy clinical

A 5M Synchronization Mechanism for Digital Twin Shop-Floor

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Chinese Journal of Mechanical Engineering 2023年第6期36卷 105-126页

作者： Weiran Liu Jiangfeng Cheng Zhiwen Wen Xiaofu Zou Zhaozong Wang Hongting Liu fei tao School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Xi’an Precision Machinery Research Institute Xi’an 710077China Institute of Artificial Intelligence Beihang UniversityBeijing 100191China Digital Twin International Research Center International Research Institute for Multidisciplinary ScienceBeihang UniversityBeijing 100191China

In recent years,as a promising way to realize digital transformation,digital twin shop-floor(DTS)plays an impor-tant role in smart manufacturing.The core feature of DTS is the synchronization.How to implement and maintain the synchronization is critical for DTS.However,there is still a lack of a common definition for synchronization in DTS.Besides,a systematic synchronization mechanism for DTS is strongly needed.This paper first summarizes the defi-nition and requirements of synchronization in DTS,to clarify the understanding of synchronization in DTS.Then,a 5M synchronization mechanism for DTS is proposed,where 5M refers to multi-system data,multi-fidelity model,multi-resource state,multi-level state,and multi-stage operation.As a bottom-up synchronization mechanism,5M synchronization mechanism for DTS has the potential to support DTS to achieve and maintain physical-virtual state synchronization,and to realize operation synchronization of DTS.The implementation methods of 5M synchronization mechanism for DTS are also introduced.Finally,the proposed synchronization mechanism is validated in a digital twin satellite assembly shop-floor,which proves the effectiveness and feasibility of the mechanism.

关键词： Digital twin Digital twin shop-floor Synchronization in digital twin shop-floor Synchronization mechanism Satellite assembly shop-floor

Digital twin-driven green material optimal selection and evolution in product iterative design

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Advances in Manufacturing 2023年第4期11卷 647-662页

作者： Feng Xiang Ya-Dong Zhou Zhi Zhang Xiao-Fu Zou fei tao Ying Zuo Key Laboratory of Metallurgical Equipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081People’s Republic of China Hubei Key Laboratory of Mechanical Transmission and Manufacturing Engineering Wuhan University of Science and TechnologyWuhan430081People’s Republic of China Institute of Artificial Intelligence Beihang UniversityBeijing100191People’s Republic of China School of Automation Science and Electrical Engineering Beihang UniversityBeijing100191People’s Republic of China Research Institute for Frontier Science Beihang UniversityBeijing100191People’s Republic of China

In recent years,green concepts have been integrated into the product iterative design in the manufacturing field to address global competition and sustainability issues.However,previous efforts for green material optimal selection disregarded the interaction and fusion among physical entities,virtual models,and users,resulting in distortions and inaccuracies among user,physical entity,and virtual model such as inconsistency among the expected value,predicted simulation value,and actual performance value of evaluation indices.Therefore,this study proposes a digital twin-driven green material optimal selection and evolution method for product iterative design.Firstly,a novel framework is proposed.Subsequently,an analysis is carried out from six perspectives:the digital twin model construction for green material optimal selection,evolution mechanism of the digital twin model,multi-objective prediction and optimization,algorithm design,decision-making,and product function verification.Finally,taking the material selection of a shared bicycle frame as an example,the proposed method was verified by the prediction and iterative optimization of the carbon emission index.

关键词： Product iterative design Digital twin(DT) Green material optimal selection Evolution mechanism Iterative optimization