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Effective Curvature Matrices and Mixed Moments of General Pulsed Paraxial Beams

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Chinese Physics Letters 1999年第12期16卷 894-895页

作者： YANG Jun fan Dian-yuan National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

On the basis of the space-time Wigner distribution function, we use the least-squares fitting method to derive the relationship between effective wavefront curvature matrices and second-order mixed moments of quasimonochromatic and polychromatic pulsed paraxial beams. The expressions here are valid for both completely coherent and partially coherent light in the three-dimensional space. Finally, the fitting method is extended to the higher-order situation;from this, a novel technique for characterizing the beam phase from the moments and their derivatives is presented.

关键词： space. axial coherent

Distributed solving Sylvester equations with fractional order dynamics

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Control Theory and Technology 2021年第2期19卷 249-259页

作者： Songsong Cheng Shu Liang yuan fan Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education School of Electrical Engineering and AutomationAnhui UniversityHefei230601AnhuiChina Key Laboratory of Knowledge Automation for Industrial Processes of Ministry of Education School of Automation and Electrical EngineeringUniversity of Science and Technology BeijingBeijing100083China

This paper addresses distributed computation Sylvester equations of the form AX+XB=C with fractional order *** partitioning parameter matrices A,B and C,we transfer the problem of distributed solving Sylvester equations as two distributed optimization models and design two fractional order continuous-time algorithms,which have more design freedom and have potential to obtain better convergence performance than that of existing first order ***,rewriting distributed algorithms as corresponding frequency distributed models,we design Lyapunov functions and prove that proposed algorithms asymptotically converge to an exact or least squares ***,we validate the effectiveness of proposed algorithms by providing a numerical example.

关键词： Fractional order calculus Distributed optimization Sylvester equation Frequency distributed model Convergence

Fair k-Center Problem with Outliers on Massive Data

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Tsinghua Science and Technology 2023年第6期28卷 1072-1084页

作者： fan yuan Luhong Diao Donglei Du Lei Liu Beijing Institute for Scientific and Engineering Computing Faculty of ScienceBeijing University of TechnologyBeijing 100124China Faculty of Management University of New BrunswickFrederictonE3B 5A3Canada

The clustering problem of big data in the era of artificial intelligence has been widely *** of the huge amount of data,distributed algorithms are often used to deal with big data *** distributed computing model has an attractive feature:it can handle massive datasets that cannot be put into the main *** the other hand,since many decisions are made automatically by machines in today’s society,algorithm fairness is also an important research area of machine *** this paper,we study two fair clustering problems:the centralized fair k-center problem with outliers and the distributed fair k-center problem with *** these two problems,we have designed corresponding constant approximation ratio *** theoretical proof and analysis of the approximation ratio,and the running space of the algorithm are given.

关键词： machine learning distributed algorithm fairness constraints outlier constraints k-center problem

Microbial Transformation of Pregnane-3β,16β,20-triol by Cunninghamella echinulata

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Chinese Journal of Chemistry 2013年第1期31卷 127-131页

作者： Chenru Yang Huafang fan yuan yuan Jinming Gao Shaanxi Engineering Center of Bioresource Chemistry & Sustainable Utilization College of Science Northwest Adow University Yangling Shaanxi 712100 China

Microbial transformation of pregnane-3β,16β,20-triol （1） by Cunninghamella echinulata afforded four previ- ously unreported polyhydroxylated steroids, namely pregnane-3β,14a,16β,20-tetrol （2）, pregnane-3-oxo-14a, 16β,20-triol （3）, pregnane-3-oxo-7β,16β,20-triol （4）, and pregnane-3fl,7β,16β,20-tetrol （5）. The structures of these metabolites were established by means of spectroscopic analysis （1D and 2D NMR as well as HRESIMS analysis）.

关键词： pregnane-3β 16β,20-triol Cunninghamella echinulata biotransformation hydroxylation biocatalysis

Spatiotemporal Instability of Ultrashort Pulses in Dispersive Self-Focusing Media

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Chinese Physics Letters 2001年第6期18卷 776-778页

作者： WEN Shuang-Chun fan Dian-yuan National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

Spatiotemporal instability in dispersive self-focusing media is investigated on the basis of a modified nonlinear Schrödinger equation(NLSE)beyond the slowly varying envelope *** is found that,for both normal and anomalous dispersions,space-time focusing may lead to the appearance of new temporal instability regions for some range of spatial *** physical origin of the new instability regions lies in the part of space-time coupling related to the fourth-order ***,space-time focusing shrinks the instability regions and slightly reduces the maximum growth rates of the original spatiotemporal instability gain spectra obtained from the standard NLSE.

关键词： slightly shrink envelope

Small-Scale Self-Focusing of Intense Laser Beams In the Presence of Vector Effect

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Chinese Physics Letters 2000年第10期17卷 731-733页

作者： WEN Shuang-Chun fan Dian-yuan National Laboratory on High Power Laser and Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800

We extend Bespalov-Talanov (B-T) theory on small-scale self-focusing (SSSF) to include vector effect of a very narrow intense laser beam with application of the vector self-focusing model. The gain spectrum for perturbations is obtained by using the standard linear instability analysis. It is shown that the influence on SSSF of vector effect is closely related to the beam width. For a very narrow beam, the role played by vector effect becomes significant, it reduces the fastest growing frequency and the maximum growth rate, and shortens the frequency range for perturbation growing, and thus deviates the gain spectrum from that of B-T theory.

关键词： Focus Small Presence

Endocytosis and Vesicular Transport of Plasmid DNA in Cells During Electric Field-Mediated Gene Delivery

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医用生物力学 2019年第A1期34卷 12-13页

作者： fan yuan Department of Biomedical Engineering Duke University

Pulsed electric field has been used widely as a nonviral approach to improving gene delivery in basic and translational research[1-2].The technique has been called electrotransfection(ET),electroporation,electrogene transfer,and gene electroinjection in the literature [1,3].It has a great potential to improve clinical treatment of diseases through delivery of vaccines and therapeutic genes,genome and epigenome editing,and generation of human induced pluripotent stem cells for tissue engineering[1-3].During ET,extracellular transport of plasmid DNA(pDNA)relies on electrophoresis,which is critical for applications in ***,mechanisms of intracellular transport remain to be *** lack of understanding has hindered the translation of ET technology to the *** is well known that pulsed electric field can generate transient hydrophilic pores in the plasma membrane(i.e.,electroporation)that permit membrane-impermeant molecules to enter *** the pores have yet to be visualized directly under a microscope,the electric field-induced membrane permeabilization has been demonstrated through experimental measurements of electrical conductance of synthetic lipid membranes and plasma membranes,direct observation of fluorescent markers crossing the membranes facing both cathode and anode,and numerical simulations of the membrane permeabilization[1,3].Results from the simulations have predicted that the cutoff size of the pores is on the order of a few hundred nanometers,and the lifetime of the pores that are larger than 100 nm is on the order of 10 *** these data provide a solid evidence of the membrane permeabilization,recent studies have demonstrated that the generation of the pores is insufficient for ET[1,4].The reasons are as ***,the lifetime of the pores is several orders of magnitude shorter than the time scale for pDNA uptake,which is on the order of 10 ***,complex formation between pDNA and plasma membrane is a neces

关键词： Endocytosis Vesicular Transport Plasmid DNA Cells During Electric Field-Mediated Gene Delivery DNA

Coverage control for heterogeneous mobile sensor networks with limited communication ranges 36

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Coverage control for heterogeneous mobile sensor networks wi...

Event-Triggered Optimal Nonlinear Systems Control Based on State Observer and Neural Network

第36届中国控制会议

作者： Cheng Song yuan fan School of Automation Nanjing University of Science and Technology School of Electrical Engineering and Automation Anhui University

ISBN: (纸本)9781538629185

The coverage control problem for heterogeneous mobile sensor networks with limited communication ranges is addressed in this paper,where the goal is to minimize a coverage cost function which indicates the largest arrival time from the mobile sensor network to the points on a circle.A distributed coverage control law is developed for each sensor via low gain feedback *** the proposed control laws,heterogeneous mobile sensors can be driven to the configuration minimizing the coverage cost function as long as the sensors’ communication ranges exceed a threshold and network connectivity of the sensors needs not to be preserved in this work.

关键词： Coverage control Mobile sensor networks Distributed control Low gain feedback

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Journal of Systems Science & Complexity 2023年第1期36卷 222-238页

作者： CHENG Songsong LI Haoyun GUO Yuchao PAN Tianhong fan yuan Anhui Engineering Laboratory of Human-Robot Integration System and Intelligent Equipment School of Electrical Engineering and AutomationAnhui UniversityHefei 230601China Key Laboratory of Intelligent Computing and Signal Processing of Ministry of Education School of Electrical Engineering and AutomationAnhui UniversityHefei 230601China

This paper develops a novel event-triggered optimal control approach based on state observer and neural network(NN)for nonlinear continuous-time ***,the authors propose an online algorithm with critic and actor NNs to solve the optimal control problem and provide an event-triggered method to reduce communication and computation ***,the authors design weight estimation for critic and actor NNs based on gradient descent method and achieve uniformly ultimate boundednesss(UUB)estimation ***,by using bounded NN weight estimation and dead-zone operator,the authors propose a triggering condition,prove the asymptotic stability of closed-loop system from Lyapunov stability perspective,and exclude the Zeno ***,the authors provide a numerical example to illustrate the effectiveness of the proposed method.

关键词： Event-triggered control neural network optimal control state observer