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Distributing pairs of vertices on Hamiltonian cycles

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Science China Mathematics 2018年第5期61卷 955-972页

作者： Weihua He Hao Li Qiang Sun Department of Applied Mathematics Guangdong University of Technology Laboratoire de Recherche en Informatique CNRS-Université Paris-Sud Institute for Interdisciplinary Research Jianghan University School of Mathematical Science Yangzhou University

Let G be a graph of order n with minimum degree δ(G)≥n/2+1. Faudree and Li(2012) conjectured that for any pair of vertices x and y in G and any integer 2≤k≤n/2, there exists a Hamiltonian cycle C such that the distance between x and y on C is k. In this paper, we prove that this conjecture is true for graphs of sufficiently large order. The main tools of our proof are the regularity lemma of Szemer′edi and the blow-up lemma of Koml′os et al.(1997).

关键词： Hamiltonian cycle Faudree-Li conjecture regularity lemma blow-up lemma

An Implicit Degree Ore-condition for Pancyclicity of Graphs

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Acta Mathematica Sinica,English Series 2013年第9期29卷 1773-1780页

作者： Hao LI Jun Qing CAI L.R.I UMR 8623 CNRS and Universit Paris-Sud 11 F-91405 Orsay France Institute for Interdisciplinary Research Jianghan University School of Management Qufu Normal University

In 1989, Zhu, Li and Deng introduced the definition of implicit degree of a vertex v in a graph G, denoted by id（v）. In this paper, we prove that if G is a 2-connected graph of order n such that id（u）＋ id（v） ≥ n for each pair of nonadjacent vertices u and v in G, then G is pancyclic unless G is bipartite, or else n = 4r, r ≥ 2 and G is isomorphic to F4r .

关键词： Implicit degree Hamilton cycle pancyclic graph

On-chip parallel Fourier transform spectrometer for broadband selective infrared spectral sensing

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Microsystems & Nanoengineering 2020年第1期6卷 1267-1275页

作者： Alaa Fathy Yasser M.Sabry Sebastien Nazeer Tarik Bourouina Diaa A.Khalil Faculty of Engineering Ain-Shams University1 Elsarayat St.AbbassiaCairoEgypt Si-Ware Systems 3 Khalid Ibn Al-Waleed St.HeliopolisCairoEgypt Universitéparis-Est ESYCOM EA 2552ESIEE Paris93162 Noisy-le-GrandFrance

Optical spectrometers enable contactless chemical ***,decreasing both their size and cost appears to be a prerequisite to their widespread ***-scale implementation of optical spectrometers still requires tackling two main ***,operation over a broad spectral range extending to the infrared is required to enable covering the molecular absorption spectrum of a broad variety of *** is addressed in our work with an Micro-Electro Mechanical Systems(MEMS)-based Fourier transform infrared spectrometer with an embedded movable micro-mirror on a silicon ***,fine spectral resolutionΔλis also required to facilitate screening over several chemicals.A fundamental limit states thatΔλis inversely proportional to the mirror motion range,which cannot exceed the chip *** boost the spectral resolution beyond this limit,we propose the concept of parallel(or multi-core)FTIR,where multiple interferometers provide complementary optical paths using the same actuator and within the same *** concept scalability is validated with 4 interferometers,leading to approximately 3 times better spectral *** the atmospheric contents of a greenhouse gas are monitored,the methane absorption bands are successfully measured and discriminated using the presented device.

关键词： interferometer spectral mirror

The synergy between the payloads on the ASO-S mission

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Research in Astronomy and Astrophysics 2019年第11期19卷 115-126页

作者： Jean-Claude Vial Institut d’Astrophysique Spatiale University Paris-Sud

This paper addresses the improved science resulting from joint observations performed by the different instruments onboard the Advanced Space-based Solar Observatory(ASO-S)mission along with ancillary instruments on missions flying at the same *** first describes the three major instruments along with their stated *** it presents some basic science issues concerning jointly observed flares,coronal mass ejections(CMEs)and eruptive prominences(EPs).Each physical candidate(magnetic reconnection,instability,hard X-ray emission and magnetic coronal field topology)is discussed in terms of its signature and identification with ASO-S *** importance of Lyαdetection and non-LTE modeling is *** instrumental and science challenges are briefly discussed.

关键词： techniques imagery,polarimetry-Sun eruptions,flares,coronal mass ejections

Ultrafast response of harmonic modelocked THz lasers

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Light(Science & Applications) 2020年第1期9卷 1530-1537页

作者： Feihu Wang Valentino Pistore Michael Riesch Hanond Nong Pierre-Baptiste Vigneron Raffaele Colombelli Olivier Parillaud Juliette Mangeney Jerome Tignon Christian Jirauschek Sukhdeep S.Dhillon Laboratoire de Physique de l’Ecole Normale Superieure ENSUniversite PSLCNRSSorbonne UniversiteUniversite de ParisParisFrance Department of Electrical and Computer Engineering Technical University of MunichArcisstr.2180333 MunichGermany Centre de Nanosciences et de Nanotechnologies CNRSUniv.Paris-SudUniversite Paris-SaclayC2N-Orsay91405 OrsayCedexFrance Ⅲ-ⅤLab 1 avenue Augustin Fresnel91767 PalaiseauFrance

The use of fundamental modelocking to generate short terahertz(THz)pulses and THz frequency combs from semiconductor lasers has become a routine affair,using quantum cascade lasers(QCLs)as a gain ***,unlike classic laser diodes,no demonstrations of harmonic modelocking,active or passive,have been shown in THz QCLs,where multiple pulses per round trip are generated when the laser is modulated at the harmonics of the cavity’s fundamental round-trip ***,using time-resolved THz techniques,we show for the first time harmonic injection and mode-locking in which THz QCLs are modulated at the harmonics of the round-trip *** demonstrate the generation of the harmonic electrical beatnote within a QCL,its injection locking to an active modulation and its direct translation to harmonic pulse generation using the unique ultrafast nature of our ***,we show indications of self-starting harmonic emission,i.e.,without external modulation,where the QCL operates exclusively on a harmonic(up to its 15th harmonic)of the round-trip *** behaviour is supported by time-resolved simulations of induced gain and loss in the system and shows the importance of the electronic,as well as photonic,nature of *** results open up the prospect of passive harmonic modelocking and THz pulse generation,as well as the generation of low-noise microwave generation in the hundreds of GHz region.

关键词： passive harmonic harmonics

A New Multi-Resource Allocation Mechanism： A Tradeoff between Fairness and Efficiency in Cloud Computing

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China Communications 2018年第3期15卷 57-77页

作者： Lihua Zhao Minghui Du Lin Chen School of Electronic and Information Engineering South China University of Technology Guangzhou 510641 China Lab. Recherche Informatique (LRI-CNRS UMR 8623)Univ. paris-sud Orsay 91405 France

This paper addresses multi-resource fair allocation: a fundamental research topic in cloud computing. To improve resource utilization under well-studied fairness constraints, we propose a new allocation mechanism called Dominant Resource with Bottlenecked Fairness(DRBF), which generalizes Bottleneck-aware Allocation(BAA) to the settings of Dominant Resource Fairness(DRF). We classify users into different queues by their dominant resources. The goals are to ensure that users in the same queue receive allocations in proportion to their fair shares while users in different queues receive allocations that maximize resource utilization subject to well-studied fairness properties such as those in DRF. Under DRBF, no user 1) is worse off sharing resources than dividing resources equally among all users; 2) prefers the allocation of another user; 3) can improve their own allocation without reducing other users' allocations; and(4) can benefit by misreporting their resource demands. Experiments demonstrate that the proposed allocation policy performs better in terms of high resource utilization than does DRF.

关键词： multi-resource fairness allocation cloud computing resource utilization

Genetic variation in birds in relation to predation risk by hawks： A comparative analysis

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Current Zoology 2015年第1期61卷 1-9页

作者： Anders P. MOLLER Jan T. NIELSEN Laboratoire d'Ecologie Systematique et Evolution CNRS UMR 8079 Universite Paris-Sud Batiment 362 F-91405 Orsay Cedex France Espedal 4 Tolne DK-9870 Sindal Denmark

The level of genetic variation among individuals may affect performance by reducing the ability of prey to detect and escape from predators if lack of genetic variation reduces flight ability directly or indirectly through reduced parasite resistance. We investigated vulnerability of common avian prey species to predation by the sparrowhawk Accipiter nisus and the goshawk A. gentilis in relation to an index of genetic similarity among adults of potential prey species. We estimated a prey vulnerability in- dex that reflects the abundance of prey relative to the expected abundance according to local population density, and related this index to band sharing coefficients based on analyses of minisatellites for adults in local breeding populations. The prey vulnera- bility index was positively correlated with the band sharing coefficient in both predators, even when controlling for potentially confounding variables. These findings indicate that prey species with high band sharing coefficients, and hence low levels of genetic variation, are more readily caught by avian predators. Therefore, predation may constitute a major cost of low levels of genetic variation in extant populations of prey [Current Zoology 61（1）： 1-9, 2015].

关键词： Band sharing Birds Minisatellites Predation risk

Numerical Approximation of a Reaction-Diffusion System with Fast Reversible Reaction

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Chinese Annals of Mathematics,Series B 2010年第5期31卷 631-654页

作者： Robert EYMARD Danielle HILHORST Hideki MURAKAWA Michal OLECH Université paris-Est 77454 Marne-la-Vallée Cedex 2France Laboratoire de Mathématiques CNRS and Universit de Paris-Sud 1191405 Orsay CédexFrance Graduate School of Science and Engineering for Research University of Toyama3190 GofukuToyama930-8555Japan Instytut Matematyczny Uniwersytetu Wroclawskiego pl.Grunwaldzki 2/450-384 WroclawPolska Laboratoire de Mathématiques CNRS Université de Paris-Sud91405 Orsay CédexFrance

The authors consider the finite volume approximation of a reaction-diffusion system with fast reversible *** is deduced from a priori estimates that the approximate solution converges to the weak solution of the reaction-diffusion problem and satisfies estimates which do not depend on the kinetic *** follows that the solution converges to the solution of a nonlinear diffusion problem,as the size of the volume elements and the time steps converge to zero while the kinetic rate tends to infinity.

关键词： Instantaneous reaction limit Mass-action kinetics Finite volume methods Convergence of approximate solutions Discrete a priori estimates Kolmogorov's theorem

Histone Deacetylase AtSRT1 Links Metabolic Flux and Stress Response in Arabidopsis

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Molecular Plant 2017年第12期10卷 1510-1522页

作者： Xiaoyun Liu Wei Wei Wenjun Zhu Lufang Su Zeyang Xiong Man Zhou Yu Zheng and Dao-Xiu Zhou Institute for Interdisciplinary Research Jianghan University Wuhan 430056 China Institute Plant Science paris-Saclay (IPS2) CNRS INRA Universite Paris-sud 11 Univeraite Paris-Saclay B630 91405 Orsay France College of Biology and Pharmaceutical Engineering Wuhan Polytechnic University Wuhan 430023 China These authors contributed equally to this article.

How plant metabolic flux alters gene expression to optimize plant growth and response to stress remains largely unclear. Here, we report that Arabidopsis thaliana NAD＊-dependent histone deacetylase AtSRT1 negatively regulates plant tolerance to stress and glycolysis but stimulates mitochondrial respiration. We found that AtSRT1 interacts with Arabidopsis cMyc-Binding Protein 1 （AtMBP-1）, a transcriptional repressor produced by alternative translation of the cytosolic glycolytic enolase gene LOS2/EN02. We demonstrated that AtSRT1 could associate with the chromatin of AtMBP-I targets LOS2/EN02 and STZ/ZATIO, both of which encode key stress regulators, and reduce the H3K9ac levels at these genes to repress their transcription. Overexpression of both AtSRT1 and AtMBP-1 had synergistic effects on the expression of glycolytic genes, glycolytic enzymatic activities, and mitochondrial respiration. Furthermore, we found that AtMBP-1 is lysine-acetylated and vulnerable to proteasomal protein degradation, while AtSRT1 could remove its lysine acetylation and significantly enhance its stability in vivo. Taken together, these results indicate that AtSRT1 regulates primary metabolism and stress response by both epigenetic regulation and modulation of AtMBP-1 transcriptional activity in Arabidopsis.

关键词： chromartin histone modification HDAC sirtuin lysine acetylation metabolism