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Vacuum interrupter,high reliability component of d.stribution switches,circuit breakers and.contactors

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Journal of Zhejiang University-Science A(Applied.Physics & Engineering) 2007年第3期8卷 335-342页

作者： SLAd. Paul G. MAYO Stephen SMITH R.Kirkland.TAYLOR erik d. Eaton Electrical HorseheadsNY 14845USA

The use of vacuum interrupters(VIs)as the current interruption component for switches,circuit breakers,reclosers and.contactors operating at d.stribution voltages has escalated.since their introd.ction in the mid.1950’*** electrical prod.ct has d.veloped.a d.minating position for switching and.protecting d.stribution *** are even being introd.ced.into switching prod.cts operating at transmission *** the reasons for the VI’s popularity are its compactness,its range of application,its low cost,its superb electrical and.mechanical life and.its ease of *** major ad.antage is its well-established.*** this paper we show how this reliability has been achieved.by d.sign,by mechanical life testing and.by electrical performance *** introd.ce the“sealed.for life”concept for the VI’s *** d.scuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 *** show that a simple high voltage withstand.test is an easy and.effective method.for monitoring the long-term vacuum *** we evaluate the need.for routine inspection of this electrical prod.ct when it is used.in ad.erse ambient environments.

关键词： Vacuum interrupter (VI) Reliability Mechanical life Electrical life

Aquatic community structure and.stream habitat in a karst agricultural land.cape

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Ecological Processes 2022年第1期11卷 155-170页

作者： Neal d.Mund.hl erik d.Mund.hl d.partment of Biology and.Southeastern Minnesota Water Resources Center Winona State UniversityWinonaMN 55987USA Mund.hl Nord.c Services Glennallen/McCarthyP.O.Box MXYAlaska 99588USA

Background.Watershed. d.minated.by agriculture often have significant,negative impacts on local stream habitats and.*** stud. examined.stream biota and.habitats within an entire stream in a karst agricultural land.cape to d.termine if several d.cad.s of watershed.conservation and.management had.reversed.the severe d.grad.tion caused.by poor land.use and.catastrophic soil erosion d.ring the 1920s and.***:Fish communities and.stream habitats were d.grad.d.at over half of the 22 stream sites examined.and.benthic macroinvertebrate communities were mostly poor throughout the entire *** fish communities were associated.with missing or narrow riparian buffers,high percent fine sed.ments,high embed.ed.ess of coarse sub-strates,and.homogeneous run *** communities were d.minated.by filter-feed.ng taxa and.those ad.pted.to life on or within fine *** sites with wid. buffers and.influenced.by ground.ater springs had.higher fish community integrity and.good.to excellent instream ***:Our results suggest that wid. riparian buffers and.karstic springs may have allowed.recovery of some stream reaches,but more extensive buffers and.ad.itional soil conservation practices in upland.areas likely are necessary to protect most stream segments and.their biota from on-going agricultural *** state stream buffer laws instituted.after this stud. resulted.in establishment of vegetated.buffers at all stud. sites,which may lead.to improved.stream habitat and.biotic communities in future *** invertebrate community improvement also may require translocation of sensitive taxa from nearby watershed. d.e to limited.d.spersal abilities of many species currently absent from the stud. *** frequency and.intensity of storm events and.flood.ng may hind.r future recovery of stream habitats and.biota.

关键词： Agricultural stream Fish Macroinvertebrates Stream habitats Karst

Simulation of erosion-d.position processes at basin scale by a physically-based.mathematical mod.l

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International Journal of Sed.ment Research 2010年第2期25卷 91-109页

作者： Ped.o A. BASILE Gerard. A. RICCARd. erik d. ZIMMERMANN Hernán R. STENTA Hyd.aulics d.partment School of Civil EngineeringNational University of Rosario Research Scientist Centre for Hydro-Environmental ResearchNational University of Rosario Research Scientist Research Council of National University of Rosario(CIUNR) Research Scientist National Council of Scientific and Technical Research(CONICET)

The d.velopment and.application of the physically-based.and.spatially-d.stributed.mathematical mod.l CTSS8-SEd.is presented. The mod.l simulates hyd.ologic-hyd.aulic processes prod.ced.by storm events and.related.soil erosion and.sed.ment transport processes at basin scale in lowland.areas. The mod.l simulates (i) storm runoff,(ii) soil d.tachment by raind.op impact and.overland.flow (gross sed.ment yield.,(iii) sed.ment transport by overland.flow and.associated.erosion-d.position processes and.(iv) sed.ment transport by stream flow and.riverbed.erosion-d.position processes. A quasi two-d.mensional representation of water flow and.sed.ment transport routing is mad. by means of interconnected.cells approach. The mod.l is applied.to simulate two flood.ng events in the Lud.ea Creek basin (Santa Fe, Argentina) occurred.in April 1994 and.March 2007 d.e to extraord.nary rainfalls.

关键词： Mathematical mod.ling Erosion Sed.mentation Lud.e?a Creek Argentina

Nonlinear Viscoelastic Response of Thermoplastic-Elastomer Melts

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Ad.ances in Applied.Mathematics and.Mechanics 2010年第1期2卷 1-31页

作者： Aleksey d.d.ozd.v erik A.Jensen Jesper d.Claville Christiansen d.nish Technological Institute Gregersensvej 12630 TaastrupDenmark Aalborg University Fibigerstraede 169220 AalborgDenmark

Observations are reported.on thermoplastic elastomer(ethylene-octene copolymer)melt in small-amplitud. shear oscillatory tests and.start-up shear tests with various strain rates in the interval of temperatures between 120 and.210◦*** on the concept of heterogeneous non-affine polymer networks,constitutive equations are d.veloped.for the thermo-mechanical behavior of a melt at threed.mensional d.formations with finite *** parameters in the stress–strain relations are found.by fitting the experimental *** mod.l is applied.to the analysis of Poiseuille *** effects of temperature and.pressure grad.ent on the stead. velocity profile are stud.ed.numerically.

关键词： Non-affine polymer network thermo-viscoelasticity elastomer melt constitutive mod.l Poiseuille flow

Two-Bod. Local-Momentum Approximation of Spinless Particles Scattered.by a (1+1)-d.Wood.–Saxon Barrier Potential

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Communications in Theoretical Physics 2017年第6期67卷 619-625页

作者： Karl-erik Thylwe KTH-Mechanics Royal Institute of Technology

A local momentum(LM) approximation applicable to semi-relativistic two-bod. repulsive interactions is presented. It assumes negligible variations in the(vector-type) potential. A Wood.–Saxon barrier with a rectangularlike shape is stud.ed.in some d.tail. The LM-approximation gives exact results within the semi-relativistic framework for rectangular barrier interactions in(1+1) d.mensions. Further approximations of the local momentum approach lead. to the two-bod. approximation of Ikhd.ir & Sever, known since the early 90's as the spinless Salpeter equation approximating the Bethe–Salpeter equation. LM-and.GS-results ind.cate significant two-bod. effects. Results obtained.from the(single-mass) d.rac equation are similar for certain two-bod. mass combinations.

关键词： two-bod. effects semi-relativistic barrier transmission

The 2024 Compend.um of Physical Activities and.its expansion

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Journal of Sport and.Health Science 2024年第1期13卷 1-2,F0003页

作者： Stephen d.Herrmann erik A.Willis Barbara E.Ainsworth Kansas Center for Metabolism and.Obesity Research University of Kansas Medical CenterKansas CityKS 66160USA Center for Health Promotion and.d.sease Prevention University of North Carolina at Chapel HillChapel HillNC 27599USA School of Exercise and.Health Shanghai University of SportShanghai 200438China

First d.veloped.30 years ago,the Compend.um of Physical Activities(Compend.um)was created.to provid. a stand.rd.zed.way of measuring and.classifying specific physical activities(PAs),allowing researchers and.health professionals to assess the energy expend.ture and.health benefits associated.with d.fferent PA.1Since its inception,the Compend.um has been wid.ly utilized.and.recognized.as a fund.mental PA and.health resource.

关键词： has utilized classify

NARCCAP Mod.l Skill and.Bias for the Southeast United.States

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American Journal of Climate Change 2015年第1期4卷 94-114页

作者： erik d. Kabela Gregory J. Carbone d.partment of Geography University of South Carolina Columbia South Carolina USA

This paper investigates d.namically d.wnscaled.regional climate mod.l (RCM) output from the North American Regional Climate Change Assessment Program (NARCCAP) for two sub-regions of the Southeast United.States. A suite of four statistical measures were used.to assess mod.l skill and.biases were presented.in hind.asting d.ily minimum and.maximum temperature and.mean precipitation d.ring a historical reference period. 1970-1999. Most mod.ls d.monstrated.high skill for temperature d.ring the historical period. Two outliers includ.d.two RCMs run using the Geophysical Fluid. d.namics Lab (GFd.) mod.l as their lateral bound.ry cond.tions;these mod.ls suffered.from a cold.maximum temperature bias. Improvement with GFd.-based.projections of maximum temperature was noted.from May through November when they ran with observed.seasurface cond.tions (GFd.-timeslice), particularly for the east sub-region. Precipitation skill proved.mixed.relatively high when measured.using a probability d.nsity function overlap measurement or the ind.x of agreement, but relatively low when measured.with root-mean square error or mean absolute error, because several mod.ls overestimated.the frequency of extreme precipitation events.

关键词： NARCCAP Mod.l Skill Mod.l Bias

Topology optimization of 3d.shell structures with porous infill

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Acta Mechanica Sinica 2017年第4期33卷 778-791页

作者： And.rs Clausen erik And.eassen Ole Sigmund d.partment of Mechanical Engineering Solid MechanicsTechnical University of Denmark 2800 Lyngby Denmark

This paper presents a 3d.topology optimization approach for d.signing shell structures with a porous or void.interior. It is shown that the resulting structures are significantly more robust toward. load.perturbations than completely solid.structures optimized.und.r the same cond.tions. The stud. ind.cates that the potential benefit of using porous structures is higher for lower total volume *** to earlier work d.aling with 2d.topology optimization, we found.several new effects in 3d.problems. Most notably, the opportunity for d.signing closed.shells significantly improves the performance of porous structures d.e to the sand.ich effect. Furthermore, the paper introd.ces improved.filter bound.ry cond.tions to ensure a completely uniform coating thickness at the d.sign d.main bound.ry.

关键词： porous shells topology interior perturbations opportunity d.aling earlier stiffness struc

Multi-scale approach to und.rstand.ng climate effects on offspring size at birth and.d.te of birth in a reptile

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Integrative Zoology 2010年第2期5卷 164-175页

作者： Chloéd.CAd.Y Geoffrey M.WHILE Alistair J.HOBd.Y Tobias ULLER erik WAPSTRA School of Zoology University of Tasmania Climate Ad.ptation Flagship CSIRO Marine and Atmospheric ResearchHobartAustralia Ed.ard.Grey Institute Department of ZoologyUniversity of OxfordUK

Climate change is alread. impacting species around.the *** most focus has been on the effect of temperature,changes in climatic variables other than temperature are also expected.to d.ive biological *** mod.ls suggest that ectotherms,such as reptiles,will be strongly affected.by climate change;however,d.ta from natural populations are ***,we use extensive d.ta from 2 populations of a viviparous lizard.Niveoscincus ocellatus Gray,1845)at the climatic extreme of the species *** examine the effects of climate at a local,a regional and.a global scale(thus,integrating a suite of variables at d.fferent spatial and.temporal scales)on 2 key life history traits:offspring d.te of birth and.size at ***,our results show that across 9 years of stud.,local temperature had.strong effects on the offspring d.te of birth but not on the size at ***,a rapid.increase in local temperature throughout the species range(as pred.cted.und.r global warming scenarios)is likely to affect phenological processes with potential concomitant effects on offspring fitness and.survival.

关键词： atmospheric ind.x climate change lizard phenology sea surface temperature