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The Moduli Space of Stable Coherent Sheaves via Non-archimedean Geometry

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Acta Mathematica Sinica,English Series 2022年第10期38卷 1722-1780页

作者： Yun feng jiang Department of Mathematics University of Kansas405 Snow Hall1460 Jayhawk BlvdLawrence USA

We provide a construction of the moduli space of stable coherent sheaves in the world of non-archimedean geometry,where we use the notion of Berkovich non-archimedean analytic *** motivation for our construction is Tony Yue Yu’s non-archimedean enumerative geometry in Gromov-Witten *** construction of the moduli space of stable sheaves using Berkovich analytic spaces will give rise to the non-archimedean version of Donaldson-Thomas *** this paper we give the moduli construction over a non-archimedean field *** use the machinery of formal schemes,that is,we define and construct the formal moduli stack of(semi)-stable coherent sheaves over a discrete valuation ring R,and taking generic fiber we get the non-archimedean analytic moduli space of semistable coherent sheaves over the fractional non-archimedean field *** generalize Joyce’s dcritical scheme structure in[37]or Kiem-Li’s virtual critical manifolds in[38]to the world of formal schemes,and Berkovich non-archimedean analytic *** an application,we provide a proof for the motivic localization formula for a d-critical non-archimedean K-analytic space using global motive of vanishing cycles and motivic integration on oriented formal d-critical *** generalizes Maulik’s motivic localization formula for the motivic Donaldson-Thomas invariants.

关键词： Non-archimedean Donaldson-Thomas theory Berkovich space analytic d-critical scheme motivic localization

Deoxygenative alkylation of tertiary amides using alkyl iodides under visible light

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Science China Chemistry 2022年第11期65卷 2231-2237页

作者： feng Zhao feng jiang Xiaoming Wang The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials College of Chemistry and Materials ScienceShanghai Normal UniversityShanghai 200234China State Key Laboratory of Organometallic Chemistry Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou310024China

It is an unceasing goal for organic chemists to develop new catalytic methodologies for functional group transformations of widespread molecular structures. Amides are readily available from simple and reliable reactions, which are common structural units found in biologically active compounds. Consequently, they are attractive to be exploited in amine synthesis by reductive cross coupling. However, deoxygenative functionalization of amides is a long-standing challenge owing to the inertness of the resonance-stabilized amide C=O bond. In this work, a deoxygenative alkylation strategy was demonstrated, which combines amides and alkyl iodides to build structurally diverse tertiary alkylamines in a single step. Compared with previous deoxygenative alkylation of amides using organometallic reagents as functional partner, this work uses stable and easily available alkyl halides as functionalization reagents. The versatile and flexible strategy plus structural and functional diversity of readily available amides and alkyl iodides renders it highly appealing for the streamlined synthesis of tertiary amines and would be of much interest in areas such as pharmaceutical and agrochemical research.

关键词： deoxygenative alkylation amide transformation alkyl radical alkylamine visible light

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Motivic Milnor Fibre of Cyclic L∞-algebras

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Acta Mathematica Sinica,English Series 2017年第7期33卷 933-950页

作者： Yun feng jiang Department of Mathematics University of Kansas405 Snow Hall 1460 Jayhawk BlvdLawrence KS 66045USA

Abstract We define the motivic Milnor fiber of cyclic L∞-algebras of dimension three using the method of Denef and Loeser of motivic integration. It is proved by Nicaise and Sebag that the topo- logical Euler characteristic of the motivic Milnor fiber is equal to the Euler characteristic of the étale cohomology of the analytic Milnor fiber. We prove that the value of Behrend function on the germ moduli space determined by a cyclic L∞-algebra L is equal to the Euler characteristic of the analytic Milnor fiber. Thus we prove that the Behrend function depends only on the formal neighborhood of the moduli space.

关键词： L∞-algebra motivic Milnor fiber analytic Milnor fiber Donaldson Thomas invariants,the Behrend function

Effective Energy Density of Glass Rejuvenation

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Acta Mechanica Solida Sinica 2022年第5期35卷 746-754页

作者： Gan Ding feng jiang Lanhong Dai Minqiang jiang State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an710049China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China

Glasses with rejuvenated structures usually exhibit improved room-temperature plasticity,which facilitates their ***,glass rejuvenation requires external energy injection to“shake up”the frozen-in disordered *** this work,we give the answer to how much the required energy *** to the constitutive model of amorphous plasticity,we find that the applied stress higher than the steady-state flow value can effectively induce the structural disordering in terms of the generation of free ***,the effective energy density(EED)of structural rejuvenation is defined as the integral of this effective stress on the corresponding *** tailoring the applied strain,strain rate,temperature and initial free volume,different degrees of structural rejuvenation are achieved,which show a generally linear correlation with the defined *** work deepens the understanding of glass rejuvenation from an energy perspective.

关键词： Glass Structural rejuvenation Effective energy density Shear transformations Free volume

Patterns and causes of geographic variation in bat echolocation pulses

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Integrative Zoology 2015年第3期10卷 241-256页

作者： Tinglei jiang Hui WU jiang feng Jilin Key Laboratory of Animal Resource Conservation and Utilization Northeast Normal UniversityChangchunChina Key Laboratory for Wetland Ecology and Vegetation Restoration of National Environmental Protection Northeast Normal UniversityChangchunChina

Evolutionary biologists have a long-standing interest in how acoustic signals in animals vary geographically,because divergent ecology and sensory perception play an important role in *** comparisons are valuable in determining the factors that influence divergence of acoustic *** are social mammals and they depend mainly on echolocation pulses to locate prey,to navigate and to *** evidence shows that geographic variation of bat echolocation pulses is common,with a mean 5-10 kHz differences in peak frequency,and a high level of individual variation may be nested in this geographical ***,understanding the geographic variation of echolocation pulses in bats is very difficult,because of differences in sample and statistical analysis techniques as well as the variety of factors shaping the vocal geographic *** differences in echolocation pulses of bats generally lack latitudinal,longitudinal and elevational patterns,and little is known about vocal *** is accumulating to support the fact that geographic variation in echolocation pulses of bats may be caused by genetic drift,cultural drift,ecological selection,sexual selection and social *** studies could relate geographic differences in echolocation pulses to social adaptation,vocal learning strategies and patterns of *** addition,new statistical techniques and acoustic playback experiments may help to illustrate the causes and consequences of the geographic evolution of echolocation pulse in bats.

关键词： Chiroptera drift echolocation geographic evolution selection

A NOTE ON STABILITY OF THE SPLIT-STEP BACKWARD EULER METHOD FOR LINEAR STOCHASTIC DELAY INTEGRO-DIFFERENTIAL EQUATIONS

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Journal of Systems Science & Complexity 2012年第5期25卷 873-879页

作者： feng jiang Yi SHEN Xiaoxin LIAO Department of Control Science and Engineering Huazhong University of Science and Technology School of Statistics and Mathematics Zhongnan University of Economics and Law Department of Control Science and Engineering the Key Laboratory of Ministry of Eduction for Image Processing and Intelligent ControlHuazhong University of Science and Technology

In the literature （Tan and Wang, 2010）, Tan and Wang investigated the convergence of the split-step backward Euler （SSBE） method for linear stochastic delay integro-differential equations （SDIDEs） and proved the mean-square stability of SSBE method under some condition. Unfortu- nately, the main result of stability derived by the condition is somewhat restrictive to be applied for practical application. This paper improves the corresponding results. The authors not only prove the mean-square stability of the numerical method but also prove the general mean-square stability of the numerical method. Furthermore, an example is given to illustrate the theory.

关键词： General mean-square stability mean-square stability split-step backward Euler method stochastic delay integro-differential equations.

Inequalities of Maximum of Partial Sums and Weak Convergence for a Class of Weak Dependent Random Variables

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Acta Mathematica Sinica,English Series 2006年第3期22卷 693-700页

作者： jiang feng WANG feng Bin LU Department of Mathematics Hangzhou Teachers College Institute of Systems Science Academy of Mathematics and Systems Science

In this paper, we establish a Rosenthal-type inequality of the maximum of partial sums for ρ^- -mixing random fields. As its applications we get the Hájeck -Rènyi inequality and weak convergence of sums of ρ^- -mi... 详细信息

关键词： ρ^- -mixing p^* -mixing NA rosenthal type inequalities weak convergence

Oil Film Stiffness of Double Involute Gears Based on Thermal EHL Theory

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 256-271页

作者： Zhaoming Yin Zhimin Fan feng jiang College of Electromechanical Engineering Qingdao University of Science&TechnologyQingdao 266061China

Lubrication failure is one of the main failure forms of gear *** varying meshing stiffness is an important factor affecting the dynamic behavior of ***,the influence of oil film stiffness is usually ignored in the research *** this paper,according to the meshing characteristics of double involute gears,based on the non-Newtonian thermal EHL theory,a new calculation method of normal and tangential oil film stiffness for double involute gears is established by the idea of subsection *** oil film stiffness difference between double involute gears and common involute gears is analyzed,and the influence of tooth waist order parameters,working conditions,and thermal effect on the oil film stiffness are *** results reveal that there are some differences between normal and tangential oil film stiffness between double involute gears and common involute gears,but there is little *** with the torque,rotation speed and initial viscosity of the lubricating oil,the tooth waist order parameters have less influence on the oil film *** effect has a certain influence on normal and tangential oil film stiffness,which indicates that the influence of thermal effect on the oil film can not be *** research proposes a calculation method of normal and tangential oil film stiffness suitable for double involute gears,which provides a theoretical basis for improving the stability of the transmission.

关键词： Double involute gear(DIG) Elastohydrodynamic lubrication(EHL) Oil film stiffness Thermal effect

Entanglement Dynamics of Arbitrary Two-Qubit Pure States under Amplitude and Phase Damping Channels

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Chinese Physics Letters 2011年第2期28卷 51-54页

作者： jiang feng-Jian SHI Ming-Jun DU jiang-feng Department of Modern Physics University of Science and Technology of China and Hefei National Laboratory for Physical Sciences at MicroscaleHefei 230026

Analytic results are presented for the entanglement evolution for arbitrary two-qubit pure state under amplitude damping and particularly phase damping *** disentanglement time and the relationship between it and the form of initial state are given *** lower bounds of disentanglement time are obtained and shown to be the monotone functions of initial concurrence.

关键词： monotone bounds arbitrary