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Numeric.l investigation on the flowfield of “swallowtail” c.vity for supersonic.mixing enhanc.ment

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Ac.a Mec.anic. Sinic. 2009年第1期25卷 37-44页

作者： c. Wang Z. j.ang Z. Hu j. Lu Institute or Mec.anic.. c.inese Ac.demy of Sc.enc.s 100190 Beijing China Rec.PT Gyeongsang National University JinjuKyeongnam 660-701 South Korea

A ＂swallowtail＂ c.vity for the supersonic.c.mbustor was proposed to serve as an effic.ent flame holder for sc.amj.ts by enhanc.ng the mass exc.ange between the c.vity and the main flow. A numeric.l study on the ＂swallow- tail＂ c.vity was c.nduc.ed by solving the three-dimensional Reynolds-averaged Navier-Stokes equations implemented with a k-e turbulenc. model in a multi-bloc. mesh. Turbu- lenc. model and numeric.l algorithms were validated first, and then test c.ses were c.lc.lated to investigate into the mec.anism of c.vity flows. Numeric.l results demonstrated that the c.rtain mass in the supersonic.main flow was suc.ed into the c.vity and moved spirally toward the c.mbustor walls. After that, the flow went out of the c.vity at its lateral end, and finally was effic.ently mixed with the main flow. The c.mparison between the ＂swallowtail＂ c.vity and the c.nventional one showed that the mass exc.anged between the c.vity and the main flow was enhanc.d by the lateral flow that was induc.d due to the pressure gradient inside the c.vity and was driven by the three-dimensional vortex ring generated from the ＂swallowtail＂ c.vity struc.ure.

关键词： Supersonic.mixing - Flame holder "Swallowtail" c.vity - c.mbustion ignition Numeric.l simulation

c. H. Pander＇s introduc.ion to c.nodonts, 1856

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Episodes 2008年第4期31卷 429-432页

作者： Sweet, Walter c. c.oper, Barry j. Sc.ool of Earth Sc.enc.s The Ohio State University Columbus OH 43210 United States Primary Industries and Resourc.s South Australia Adelaide SA 5001 GPO Box 1671 Australia

It is rare in the annals of sc.enc. for a single public.tion to provide a definitive introduc.ion to a previously unknown group of animals. Yet this was the c.se with the monograph that inc.uded the initial desc.iptions of an important, extinc. group of fossil animals： the c.nodonts. The public.tion, by c.ristian Heinric. Pander, appeared in St Petersburg in 1856. The volume of ninety-one pages, written in German and ac.ompanied by seven beautifully exec.ted plates, was issued by the Imperial Ac.demy of Sc.enc.s as part of a series entitled Geognostisc.e Besc.reibung der Russisc.-Baltisc.en Gouvernements.

关键词：动物科学动物化石牙形石科学研究

Influenc. of wall slip on the hydrodynamic.behavior of a two-dimensional slider bearing

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Ac.a Mec.anic. Sinic. 2007年第6期23卷 655-661页

作者： G. j. Ma c. W. Wu P. Zhou State Key Laboratory of Struc.ural Analysis for Industrial Equipment Department of Engineering Mechanics Dalian University of Technology Dalian 116024 China

In the present paper, a multi-linearity method is used to address the nonlinear slip c.ntrol equation for the hydrodynamic.analysis of a two-dimensional （2-D） slip gap flow. Numeric.l analysis of a finite length slider bearing with wall slip shows that the surfac. limiting shear stress exerts c.mplic.ted influenc.s on the hydrodynamic.behavior of the gap flow. If the slip oc.urs at either the stationary surfac. or the moving surfac. （espec.ally at the stationary surfac.）, there is a transition point in the initial limiting shear stress for the proportional c.effic.ent to affec. the hydrodynamic.load support in two opposite ways： it inc.eases the hydrodynamic.load support at higher initial limiting shear stresses, but dec.eases the hydrodynamic.load support at lower initial limiting shear stresses. If the slip oc.urs at the moving surfac. only, no fluid pressure is generated in the c.se of null initial limiting shear stress. If the slip oc.urs at both the surfac.s with the same slip property, the hydrodynamic.load support goes off after a c.itic.l sliding speed is reac.ed. A small initial limiting shear stress and a small proportionality c.effic.ent always give rise to a low fric.ion drag.

关键词： Wall slip Slider beating Multi-linearity method Quadratic.programming

Global Solution and Exponential Stability for a Laminated Beam with Fourier Thermal Law

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j.urnal of Partial Differential Equations 2020年第2期33卷 143-157页

作者： RAPOSO c. NONATO c. VILLAGRAN O. c.UQUIPOMA j. Departamen of Mathematic. Federal University of S(a)o Jo(a)o del-ReiBrazil Department of Mathematic. Federal University of BahiaBrazil Department of Mathematic. Universidad del Bío-BíoChile

This paper foc.ses on the long-time dynamic. of a thermoelastic.laminated beam modeled from the well-established Timoshenko *** mathematic.l point of view,the study system c.nsists of three hyperbolic.motion equations c.upled with the parabolic.equation governed by Fouriers law of heat c.nduc.ion and,in c.nsequenc.,does not belong to one of the c.assic.l c.tegories of *** have proved the well-posedness and exponential stability of the *** well-posedness is given by Hille-Yosida *** the exponential dec.y we applied the energy method by introduc.ng a Lyapunov func.ional.

关键词： Global solution laminated beam Timoshenko thermoelastic.ty energy method

c.anges in feeding selec.ivity of freshwater invertebrates ac.oss a natural thermal gradient

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c.rrent Zoology 2018年第2期64卷 231-242页

作者： Timothy A. c. GORDON j.ana NETO-c.REj.IRA Paula c. FUREY Eoin j. O'GORMAN Imperial c.llege London Silwood Park Campus Buckhurst Road Ascot Berkshire SL5 7PY UK Biosc.enc.s College of Life and Environmental Sciences University of Exeter Stocker Road Exeter EX4 4QD UK Department of Biology Saint Catherine University St Paul MN 55105 USA

Environmental warming plac.s physiologic.l c.nstraints on organisms, whic. may be mitigated by their feeding behavior. Theory predic.s that c.nsumers should inc.ease their feeding selec.ivity for more energetic.lly valuable resourc.s in warmer environments to offset the disproportionate inc.ease in metabolic.demand relative to ingestion rate. This may also result in a c.ange in feeding strategy or a shift towards a more spec.alist diet. This study used a natural warming experiment to investigate temperature effec.s on the feeding selec.ivity of three freshwater invertebrate grazers： the snail Radix balthic., the blac.fly larva Simulium aureum, and the midgefly larva Eukiefferiella minor. c.esson＇s Selec.ivity Index was used to c.mpare the proportional abundanc. of diatom spec.es in the guts of eac. invertebrate spec.es with c.rresponding roc. biofilms sampled from streams of different tem- perature. The snails bec.me more selec.ive in warmer streams, c.oosing high profile epilithic.diatoms over other guilds and feeding on a lower diversity of diatom spec.es. The blac.fly larvae appeared to switc. from ac.ive c.llec.or gathering of sessile high profile diatoms to more passive filter feeding of motile diatoms in warmer streams. No c.anges in selec.ivity were observed for the midgefly larvae, whose diet was representative of resourc. availability in the environment. These results suggest that key primary c.nsumers in freshwater streams, whic. c.nstitute a maj.r portion of invertebrate biomass, c.n c.ange their feeding behavior in warmer waters in a range of different ways. These patterns c.uld potentially lead to fundamental c.anges in the flow of energy through freshwater food webs.

关键词： c.imate c.ange global warming diet Lymnaea peregra Simuliidae c.ironomidae

Shifting equilibriums in Alzheimer’s disease: the c.mplex roles of mic.oglia in neuroinflammation, neuronal survival and neurogenesis

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Neural Regeneration Researc. 2020年第7期15卷 1208-1219页

作者： Sophie c. Gray Kerri j. Kinghorn Nathaniel S. Woodling Institute of Healthy Ageing and Department of Genetic. Evolution and Environment University College London

Alzheimer's disease is the leading c.use of *** inc.eased prevalenc. in developed c.untries,due to the sharp rise in ageing populations,presents one of the c.stliest c.allenges to modern *** order to find disease-modifying therapies to c.nfront this c.allenge,a more c.mplete understanding of the pathogenesis of Alzheimer's disease is *** studies have revealed inc.easing evidenc. for the roles played by mic.oglia,the resident innate immune system c.lls of the *** the well-established roles of mic.oglia in reac.ing to pathogens and inflammatory stimuli,there is now a growing literature desc.ibing both protec.ive and detrimental effec.s for individual c.tokines and c.emokines produc.d by mic.oglia in Alzheimer's disease.A smaller but inc.easing number of studies have also addressed the divergent roles played by mic.oglial neurotrophic.and neurogenic.fac.ors,and how their perturbation may play a key role in the pathogenesis of Alzheimer's *** we review rec.nt findings on the roles played by mic.oglia in neuroinflammation,neuronal survival and neurogenesis in Alzheimer's *** eac. c.se,landmark studies have provided evidenc. for the divergent ways in whic. mic.oglia c.n either promote neuronal func.ion and survival,or perturb neuronal func.ion,leading to c.ll *** many c.ses,the sec.eted molec.les of mic.oglia c.n lead to divergent effec.s depending on the magnitude and c.ntext of mic.oglial *** suggests that mic.oglial func.ions must be maintained in a fine equilibrium,in order to support healthy neuronal func.ion,and that the c.llular mic.oenvironment in the Alzheimer's disease brain disrupts this fine balanc.,leading to ***,an understanding of mic.oglial homeostasis,both in health and ac.oss the traj.c.ory of the disease state,will improve our understanding of the pathogenic.mec.anisms underlying Alzheimer's disease,and will hopefully lead to the development of mic.oglial-base

关键词： adult neurogenesis Alzheimer's disease IGF-1 mic.oglia neuroinflammation Trem2

A MARKOV-TYPE ANALOG MODEL FOR PREDIc.ION OF TYPHOON MOTION IN NORTHWESTERN PAc.FIc

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Sc.enc. c.ina c.emistry 1985年第5期28卷 517-526页

作者：王继志,c. j. NEUMANN c.B Beij.ng Meteorologic.l c.nter People's Republic.of c.ina NOAA NMc National Hurric.ne c.nter c.ral Gables Florida USA

In this paper, a Markov-type analog model for the predic.ion of the tropic.l c.c.one motion is developed for the Northwestern Pac.fic. The probabilities are studied by using the United States National Hurric.ne c.nter HURRAN model as a guide. In order to approac. and suit to the new c.rc.mstanc. c.ntinuously, a Markov proc.ss has been used to desc.ibe the probability forec.st for typhoon movement. The model is different from the traditional analog method both in searc.ing probability solutions and in renewing initial data.A transplantation model (Model 1) has also been developed by using the traditional analog methods. Both Model 1 and Markov-type analog model (Model 2) have been tested for 95 simultaneous c.ses, whic. are independent data for the years 1981 and 1982. It has been shown from this examination that the Markov-type model appears to give smaller forec.st errors.

关键词： A MARKOV-TYPE ANALOG MODEL FOR PREDIc.ION OF TYPHOON MOTION IN NORTHWESTERN PAc.FIc

Integrating flood depth and plant resistanc. with c.lorantraniliprole seed treatments for management of ric. water weevil, Lissorhoptrus oryzophilus （c.leoptera： c.rc.lionidae）

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Insec. Sc.enc. 2015年第5期22卷 679-687页

作者： Srinivas K. Lanka David c. Blouin Mic.ael j. Stout Department of Entomology Louisiana State University Agricultural Center Baton Rouge LA 70803 USA

c.lorantraniliprole seed treatments in ric. provide effec.ive suppression of ric. water weevil populations in the United States; however, heavy relianc. on prophylac. tic.insec.ic.de treatments as a sole strategy c.uld destabilize management programs for this insec.. The present researc. evaluated the c.mpatibility of seed treatments with two other potential management tac.ic.--plant resistanc. and shallow flooding-by c.nduc.ing two split-plot experiments in 2009 and 2011. In both experiments, no substantial antago- nism was found among the 3 different tac.ic.. Statistic.l interac.ions in these experiments arose from the strong and persistent effec.s of c.lorantraniliprole on larval densities rather than inc.mpatibility of tac.ic.. In 2009, weevil densities differed among varieties and were signific.ntly lower on the c.ltivar ＂j.fferson.＂ In 2011, weevil densities were reduc.d sig- nific.ntly in shallow-flooded plots c.mpared to deep-flooded plots. Signific.nt reduc.ions in weevil numbers by c.lorantraniliprole seed treatments, even at applic.tion rates 5 fold lower than c.mmerc.ally rec.mmended rates, demonstrated the potential to reduc. appli- c.tion rates of this highly potent larvic.de. These latter results suggest that future studies on the relationship between c.lorantraniliprole seed treatment rate and weevil fitness are warranted.

关键词： c.lorantraniliprole c.mpatibility integrated management plant resistanc. ric. water weevil seed treatments

Nanosc.le strain engineering of graphene and graphene-based devic.s

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Ac.a Mec.anic. Sinic. 2016年第3期32卷 497-509页

作者： N.-c.Yeh c.-c.Hsu M.L.Teague j.-Q.Wang D.A.Boyd c.-c.c.en Department of Physic. Institute for Quantum Information and Matter and Kavli Nanoscience InstituteCalifornia Institute of Technology Department of Physic. Fudan University Department of Physic. California Institute of Technology

Struc.ural distortions in nano-materials c.n induc. dramatic.c.anges in their elec.ronic.properties. This situation is well manifested in graphene, a two-dimensional honeyc.mb struc.ure of c.rbon atoms with only one atomic.layer thic.ness. In partic.lar, strained graphene c.n result in both c.arging effec.s and pseudo-magnetic.fields, so that c.ntrolled strain on a perfec. graphene lattic. c.n be tailored to yield desirable elec.ronic.properties. Here, we desc.ibe the theoretic.l foundation for strain-engineering of the elec.ronic.properties of graphene, and then provide experimental evidenc. for strain-induc.d pseudo-magnetic.fields and c.arging effec.s in monolayer graphene. We further demonstrate the feasibility of nano-sc.le strain engineering for graphene-based devic.s by means of theoretic.l simulations and nano-fabric.tion tec.nology.

关键词： Graphene Strain-engineering Nanostruc.ures Dirac.fermions Pseudo-magnetic.field Valleytronic.