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Taxonomic dependency and spatial heterogeneity in assembly mechanisms of.bacteria across complex coastal waters

Ecological Processes 2024年第1期13卷 80-97页

作者： Huizhen Yan Dandan Lin Gaoke gu Yuj.e Huang Xuya Hu Zhenhao Yu Dandi Hou Demin Zhang Barbara j.Campbell Kai Wang State Key Laboratory f.r Managing Biotic and Chemical Threats to the Quality and Saf.ty of.Agro-Products School of Marine SciencesNingbo University Key Laboratory of.Marine Biotechnology of.Zhej.ang Province School of Marine Sciences Ningbo University Department of.Biological Sciences Clemson University

Background Understanding community assembly mechanisms across taxa and space is f.ndamental f.r microbial ecology. However, the variability and determinants of.assembly processes over taxa and space remain unclear. Here, we investigated taxonomic dependency and spatial heterogeneity in bacterial assembly mechanisms across coastal waters in the East China Sea using neutral and null models with customized visualization *** Overall, bacterial assembly mechanisms varied across broad taxonomic groups(phyla and proteobacterial classes) and space at the regional scale. A determinism–stochasticity balanced mechanism governed total bacterial assembly, while taxonomic dependency existed in assembly mechanisms and ecological processes. Among community ecological f.atures, niche breadth and negative-to-positive cohesion ratio were strongly associated with the determinism-to-stochasticity ratio of.bacterial groups. Bacterial assembly mechanisms commonly exhibited spatial heterogeneity, the extent and determinants of.which varied across taxonomic groups. Spatial assembly of.total bacteria was directly driven by many environmental f.ctors and potential interactions between taxa, but not directly by geographic f.ctors. Overall, the bacterial groups with higher spatial heterogeneity in assembly mechanisms were more related to environmental and/or geographic f.ctors(except Bacteroidetes), while those with lower heterogeneity were more related to ecological *** Our results conf.rm the pervasiveness of.taxonomic dependency and spatial heterogeneity in bacterial assembly, providing a f.ner understanding about regulation across complex coastal waters.

关键词： Bacterioplankton Assembly mechanism Niche breadth Null model Environmental gradient Biogeography

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Emergent symmetry in quantum phase transition:f.om deconf.ned quantum critical point to gapless quantum spin liquid

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Science Bulletin 2024年第2期69卷 190-196页

作者： Wen-Yuan Liu Shou-Shu Gong Wei-Qiang Chen Zheng-Cheng gu Department of.Physics The Chinese University of Hong KongHong KongChina Division of.Chemistry and Chemical Engineering California Institute of TechnologyPasadena CA 91125USA School of.Physical Sciences Great Bay UniversityDongguan 523000China Great Bay Institute f.r Advanced Study Dongguan 523000China Department of.Physics and Shenzhen Institute f.r Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of.Advanced Quantum f.nctional Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

The emergence of.exotic quantum phenomena in f.ustrated magnets is rapidly driving the development of.quantum many-body physics,raising f.ndamental questions on the nature of.quantum phase *** we unveil the behaviour of.emergent symmetry involving two extraordinarily representative phenomena,i.e.,the deconf.ned quantum critical point(DQCP)and the quantum spin liquid(QSL)*** large-scale tensor network simulations,we study a spatially anisotropic spin-1/2 square-lattice f.ustrated antif.rromagnetic(Af.)model,namely the j.x-j.y-j. model,which contains anisotropic nearestneighbor couplings j.x,j.y and the next nearest neighbor coupling *** small j.y/j.x,by tuning j.,a direct continuous transition between the Af. and valence bond solid phase is *** growing j.y/j.x,a gapless QSL phase gradually emerges between the Af. and VBS *** observe an emergent O(4)symmetry along the Af.–VBS transition line,which is consistent with the prediction of.DQCP *** surprisingly,we f.nd that such an emergent O(4)symmetry holds f.r the whole QSL–VBS transition line as *** f.ndings reveal the intrinsic relationship between the QSL and DQCP f.om categorical symmetry point of.view,and strongly constrain the quantum f.eld theory description of.the QSL *** phase diagram and critical exponents presented in this paper are of.direct relevance to f.ture experiments on f.ustrated magnets and cold atom systems.

关键词： Tensor network Quantum phase transition Emergent symmetry Quantum spin liquid Deconf.ned quantum critical point Anisotropic

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Turbo-shaf. engine adaptive neural network control based on nonlinear state space equation

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Chinese j.urnal of.Aeronautics 2024年第4期37卷 493-507页

作者： Ziyu gu Qiuhong LI Shuwei PANG Wenxiang ZHOU j.chang WU Chenyang ZHANG j.angsu Province Key Laboratory of.Aerospace Power System Nanjing University of Aeronautics and AstronauticsNanjing 210016China AECC Hunan Aviation Powerplant Research Institute Zhuzhou 412002China

Intelligent Adaptive Control(AC) has remarkable advantages in the control system design of.aero-engine which has strong nonlinearity and uncertainty. Inspired by the Nonlinear Autoregressive Moving Average(NARMA)-L2 adaptive control, a novel Nonlinear State Space Equation(NSSE) based Adaptive neural network Control(NSSE-AC) method is proposed f.r the turbo-shaf. engine control system design. The proposed NSSE model is derived f.om a special neural network with an extra layer, and the rotor speed of.the gas turbine is taken as the main state variable which makes the NSSE model be able to capture the system dynamic better than the NARMA-L2 model. A hybrid Recursive Least-Square and Levenberg-Marquardt(RLS-LM) algorithm is advanced to perf.rm the online learning of.the neural network, which f.rther enhances both the accuracy of.the NSSE model and the perf.rmance of.the adaptive controller. The f.edback correction is also utilized in the NSSE-AC system to eliminate the steady-state tracking error. Simulation results show that, compared with the NARMA-L2 model, the NSSE model of.the turboshaf. engine is more accurate. The maximum modeling error is decreased f.om 5.92% to 0.97%when the LM algorithm is introduced to optimize the neural network parameters. The NSSE-AC method can not only achieve a better main control loop perf.rmance than the traditional controller but also limit all the constraint parameters ef.iciently with quick and accurate switching responses even if.component degradation exists. Thus, the ef.ectiveness of.the NSSE-AC method is validated.

关键词： Adaptive control systems Turbo-shaf. engine Neural network Nonlinear state space equation NARMA-L2

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Thermo-kinetic characteristics on stabilizing hetero-phase interf.ce of.metal matrix composites by crystal plasticity f.nite element method

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j.urnal of.Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.B.Zhang S.j.Song f.Liu State Key Laboratory of.Solidif.cation Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity f.nite element(3D CPf.)simulations,co-def.rmation and instability of.hetero-phase interf.ce in dif.erent material systems were herein studied f.r polycrystalline metal matrix composites(MMCs).Local stress and strain f.elds in two types of.3layer MMCs such as f.c/f.c Cu-Ag and f.c/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interf.ce instability can be observed in the f.c/bcc systems than in the f.c/f.c systems upon ref.ning to metallic nanolayered composites(MNCs).By detailed analysis of.stress and strain localization,it has been demonstrated that the interf.ce instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then f.llows that the thermodynamic driving f.rceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classif. the def.rmation modes,f.llowing the so-called thermo-kinetic *** by inserting a high density of.high-energy interf.ces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interf.ce allows a successf.l establishment of.MMCs with the high△G-high Q def.rmation mode,which ensures high hardening and unif.rm strain distri-bution,thus ef.iciently suppressing the shear band,stabilizing the hetero-phase interf.ce,and obtaining an exceptional combination in strength and *** hetero-phase interf.ce chosen by a couple of.thermodynamics and kinetics can be def.ned as breaking the thermo-kinetic correlation and has been proposed f.r artif.cially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interf.ce Crystal plasticity f.nite element

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Synthesis of.Silver Nanoparticles f.om Honeybees and Its Antibacterial Potential

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Open j.urnal of.Medical Microbiology 2024年第1期14卷 77-92页

作者： Akamu j. Ewunkem Niore’s j.hnson A’lyiha f. Beard Ilunga Tshimanga Brittany j.stice j.f.ery Meixner Department of.Biological Sciences Winston Salem State University Winston Salem NC USA Department of.Clinical Science and Laboratory Science Winston Salem State University Winston Salem NC USA

Honeybees (Apis mellif.ra) are important pollinators of.f.owering plants and agricultural crops contributing annually to billions of.dollars in revenues to crop production. Honeybees have an average lif.span between 8 weeks to 5 years. Dead honeybees are abundantly available in beehives and can be utilized as an alternative source to synthesize nanoparticles. In recent years, biologically synthesized nanoparticles have been pref.rred over their chemical counterparts. However, honeybee-based-green synthesis of.nanoparticles has not been explored yet. Herein, we report the biosynthesis of.silver nanoparticles f.om honeybees and its antibacterial activity. The synthesis of.silver nanoparticles was monitored visually through a gradual change in color. f.rthermore, the biosynthesized nanoparticles were conf.rmed and characterized by UV-visible spectroscopy. Scanning Electron Microscope was utilized to analyze the average size and morphologies of.the biosynthesized nanoparticles. Subsequently, the antibacterial potential of.the biosynthesized silver nanoparticles was tested against selected Gram-positive and Gram-negative bacterial strains. It was f.und that a distinct color change f.om yellow to brown in the reaction solution suggested the f.rmation of.silver nanoparticles. The biosynthesized nanoparticles exhibited absorption maxima at 430 nm. The SEM analysis conf.rmed the spherical and cuboidal shape of.the biosynthesized silver nanoparticles with a size range between 10 - 40 nm. f.rthermore, the biosynthesized silver nanoparticles exhibited strong antimicrobial potential against tested Gram-positive and Gram-negative bacteria strains by aggregating on the cell surf.ce. This study showcases the biomedical and agricultural applications of.biosynthesized silver nanoparticles f.om honeybee wings. .

关键词： Honeybee Bacteria Green Synthesis Nanoparticles Antimicrobial

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On the analytical solution of.transient f.iction in channel f.ows

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1447-1466页

作者： f.j.GARCíA-GARCíA P.f.RINAS-ALVARINO Department of.Naval&Industrial Engineering Polytechnic School of EngineeringUniversity of A CorunaCampus Industrial de FerrolFerrol 15403A CorunaSpain Integraciones Técnicas de Seguridad S.A.Pol.Ind.Espiritu SantoC/Nobel15Cambre 15650A CorunaSpain

The transient f.iction in channel mean f.ows is the sum of.two contributions,i.e.,the underlying laminar f.ow(ULf.and the purely turbulent component(PTC),and the contributions are analyzed separately by theoretical *** is f.und that,the transient f.iction may be higher or remarkably lower than that in equal-Reynolds number steady-state *** universal time constant f.r plane-parallel laminar f.ows is reported,and the role of.the time constant in a turbulent mean f.ow is *** is shown that the time constant is related to the turbulence's f.ozen ***,a study of.the logarithmic layer during the transient f.ow is accomplished,which shows that the logarithmic layer is destroyed.

关键词： transient f.iction transient f.ow unsteady channel f.ow

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Rethinking multi-spatial inf.rmation f.r transf.rable adversarial attacks on speaker recognition systems

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CAAI Transactions on Intelligence Technology 2024年第3期9卷 620-631页

作者： j.nj.an Zhang Hao Tan Le Wang Yaguan Qian Zhaoquan gu guangzhou University GuangzhouChina Department of.New Networks Peng Cheng LaboratoryShenzhenChina Harbin Institute of.Technology(Shenzhen) ShenzhenChina Zhej.ang University of.Science and Technology HangzhouChina

Adversarial attacks have been posing signif.cant security concerns to intelligent systems,such as speaker recognition systems(SRSs).Most attacks assume the neural networks in the systems are known bef.rehand,while black-box attacks are proposed without such inf.rmation to meet practical *** black-box attacks improve trans-f.rability by integrating multiple models or training on multiple datasets,but these methods are *** by the optimisation strategy with spatial inf.rmation on the perturbed paths and samples,we propose a Dual Spatial Momentum Iterative f.st Gradient Sign Method(DS-MI-f.SM)to improve the transf.rability of.black-box at-tacks against ***,DS-MI-f.SM only needs a single data and one model as the input;by extending to the data and model neighbouring spaces,it generates adver-sarial examples against the integrating *** reduce the risk of.overf.tting,DS-MI-f.SM also introduces gradient masking to improve *** authors conduct extensive experiments regarding the speaker recognition task,and the results demonstrate the ef.ectiveness of.their method,which can achieve up to 92%attack success rate on the victim model in black-box scenarios with only one known model.

关键词： speaker recognition spoof.ng attacks

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Collisionless shock acceleration of.protons in a plasma slab produced in a gas j.t by the collision of.two laser-driven hydrodynamic shockwaves

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Matter and Radiation at Extremes 2024年第2期9卷 12-25页

作者： j.-R.Marquès L.Lancia P.Loiseau P.f.restier-Colleoni M.Tarisien E.Atukpor V.Bagnoud C.Brabetz f.Consoli j.Domange f.Hannachi P.Nicolaï M.Salvadori B.Zielbauer LULI CNRSÉcole PolytechniqueCEASorbonne UniversitéInstitut Polytechnique de Paris91128 Palaiseau CedexFrance CEA DAMDIF91297 Arpajon CedexFrance UniversitéParis-Saclay CEALMCE91680 Bruyères-le-ChatelFrance CENBG CNRS-IN2P3Universitéde Bordeaux33175 Gradignan CedexFrance GSI Helmholtzzentrum f.r Schwerionenf.rschung GmbH Planckstraße 164291 DarmstadtGermany University of.Darmstadt Schloßgartenstr.764289 DarmstadtGermany ENEA f.sion and Technologies f.r Nuclear Saf.ty Department C.R.FrascatiVia Enrico Fermi 45FrascatiRomeItaly CELIA Universitéde Bordeaux–CNRS–CEA33405 TalenceFrance UniversitéParis-Saclay CEALIDYL91191 Gif-sur-YvetteFrance

We have recently proposed a new technique of.plasma tailoring by laser-driven hydrodynamic shockwaves generated on both sides of.a gas j.t[Marquès et al.,*** 28,023103(2021)].In a continuation of.this numerical work,we study experimentally the inf.uence of.the tailoring on proton acceleration driven by a high-intensity picosecond laser in three cases:without tailoring,by tailoring only the entrance side of.the picosecond laser,and by tailoring both sides of.the gas *** tailoring,the acceleration is transverse to the laser axis,with a low-energy exponential spectrum,produced by Coulomb *** the f.ont side of.the gas j.t is tailored,a f.rward acceleration appears,which is signif.cantly enhanced when both the f.ont and back sides of.the plasma are *** f.rward acceleration produces higher-energy protons,with a peaked spectrum,and is in good agreement with the mechanism of.collisionless shock acceleration(CSA).The spatiotemporal evolution of.the plasma prof.le is characterized by optical shadowgraphy of.a probe *** ref.action and absorption of.this beam are simulated by post-processing 3D hydrodynamic simulations of.the plasma *** with the experimental results allows estimation of.the thickness and near-critical density of.the plasma slab produced by tailoring both sides of.the gas *** parameters are in good agreement with those required f.r CSA.

关键词： acceleration hydrodynamic collision

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Inf.ow and outf.ow permeability tests in a very sof. clay under low stresses

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j.urnal of.Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 3270-3283页

作者： j.W.S.Vargas f.A.B.Danziger f.R.Lopes T.Lunne f.deral University of.Rio de j.neiro Rio de JaneiroBrazil Norwegian Geotechnical Institute OsloNorway

In situ inf.ow and outf.ow permeability tests with the BAT probe at SarapuíII sof. clay test site are presented.A description of.the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of.very sof. clays under low *** pressures were monitored during probe installation and were f.und to be slightly lower than piezocone u2 pore pressures,consistent with the position of.the *** role of.f.lter tip saturation was investigated af.er the usual saturation procedure provided an unsatisf.ctory pore pressure response during probe *** show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of.the coef.icient of.permeability determination in early *** inf.ow and outf.ow tests yielded similar results,indicating that caref.l execution of.the test can lead to good test repeatability regardless of.the loading *** sequences of.alternated inf.ow and outf.ow tests have yielded similar results,indicating that soil reconsolidation and f.lter clogging were negligible in the tests *** are presented concerning the relationship between index parameters and the in situ coef.icient of.permeability f.r SarapuíII clay,which plot outside the range of.existing databases.

关键词： Permeability test Sof. clay BAT probe Inf.ow and outf.ow tests

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A Possible X-ray Quasi-periodic Oscillation in the Narrow-line Seyf.rt 1 Galaxy Mrk 142

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Research in Astronomy and Astrophysics 2024年第6期24卷 191-200页

作者： Xiao-gu Zhong j.an-Cheng Wang Yong-Yun Chen Xiao-Ling Yu College of.Physics and Electronic Engineering Qujing Normal UniversityQujing 655011China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

A possible quasi-periodic oscillation(QPO) at f.equency 7.045 × 10^(-5) Hz is f.und in the narrow-line Seyf.rt 1galaxy Mrk 142 in the data of.XMM-Newton collected on 2020 April *** f.nd that the QPO signal is statistically signif.cantly larger than the 5σ level and highly coherent with quality f.ctor Q > 5 at the 0.3–10 keV band by using the method of.the Lomb–Scargle Periodogram,the Weighted Wavelet Z-transf.rm and the *** analyze the data in 0.3–0.6 keV,0.6–1 keV,1–3 keV and 3–10 keV energy bands,and f.nd obvious QPO signals at 0.3–0.6 keV and 1–3 keV *** then analyze the time-average spectra and time variability at the QPO f.equency of.7.045 × 10^(-5) Hz,and use a model to f.t *** f.nd that the QPO signal mainly comes f.om the X-ray hot corona.

关键词： X-rays:galaxies galaxies:Seyf.rt accretion accretion disks radiation mechanisms:general

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