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Seismic behavior.of var.able fr.quency pendulum isolator

作者： azure

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Ear.hquake Engineer.ng and Engineer.ng Vibr.tion 2008年第2期7卷 193-205页

作者： V. r. Panchal r. S. Jangid Depar.ment of Civil Engineer.ng Indian Institute of TechnologyBombayPowaiMumbai 400076India

Ear.hquake per.or.ance of a flexible one-stor. building isolated with a var.able fr.quency pendulum isolator.（VFPI） under.near.fault and far.field gr.und motions is investigated. The fr.ctional for.es mobilized at the inter.ace of the VFPI ar. assumed to be velocity dependent. The inter.ction between fr.ctional for.es of the VFPI in two hor.zontal dir.ctions is duly consider.d and coupled differ.ntial equations of motion of the isolated system in the incr.mental for. ar. solved iter.tively. The r.sponse of the system with bi-dir.ctional inter.ction is compar.d with those without inter.ction. In addition, the effects of velocity dependence on the r.sponse of the isolated system ar. also investigated. Mor.over. a par.metr.c study is car.ied out to cr.tically examine the influence of impor.ant par.meter. on bi-dir.ctional inter.ction effects of the fr.ctional for.es of the VFPI. These par.meter. ar.： the super.tr.ctur. time per.od, fr.quency var.ation factor.（FVF） and fr.ction coefficient of the VFPI. Fr.m the above investigations, it is obser.ed that the dependence of the fr.ction coefficient on r.lative velocity of the system does not have a noticeable effect on the peak r.sponse of the system isolated with VFPI, and that the bi-dir.ctional inter.ction of fr.ctional for.es of the VFPI is impor.ant and if neglected, isolator.displacements will be under.stimated and the super.tr.ctur. acceler.tion and base shear.will be over.stimated.

关键词： base isolation bi-dir.ctional inter.ction super.tr.ctur. flexibility near.fault gr.und motion fr.ction coefficient far.field gr.und motion VFPI

Human-Like r.bot Sensing Mediated by Body Heat

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Jour.al of Bionic Engineer.ng 2014年第1期11卷 82-89页

作者： r. Andr.w r.ssell Depar.ment of Electr.cal and Computer.Systems Engineer.ng Monash University Clayton VIC 3800 Australia

This paper.pr.sents a novel r.botic sensor.system that can monitor.volatile chemicals and air.low. The system is modelled on char.cter.stics of the human body that ar. thought to have a significant influence on the human odour.and air.low senses. In par.icular. the effect of buoyant air.low due to body heat acts to gather.volatile chemicals over.lar.e ar.as of the human body and car.y them to the nose. It is postulated that this effect incr.ases the r.ceptive ar.a for.human olfaction. In addition, the inter.ction between r.sing air.heated by the body and exter.al air.low pr.duces a temper.tur. distr.bution about head height that can be used to infer.air.low dir.ction and magnitude. A heated sensor.system was constr.cted to investigate these effects and the r.sulting sensor.was mounted on a mobile r.bot. The design of the sensor.system is descr.bed. r.sults ar. pr.sented which demonstr.te its ability to measur. air.low dir.ction and detect chemical signals over.a wider.r.ceptive field compar.d with an unheated sensor.

关键词： sensing volatile chemicals sensing air.low human body heat biomimetic r.bots

Ser.iceability analysis of deep under.r.und openings dr.ven in jointed-r.ck

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Inter.ational Jour.al of Mining Science and Technology 2017年第6期27卷 1019-1024页

作者： Abdellah Wael r. Mining and Metallur.ical Engineer.ng Depar.ment Faculty of Engineering University of Assiut Assiut 71515 Egypt

The per.or.ance of under.r.und excavations is inevitably influenced by r.ck mass char.cter.stics, pr.sence of joints and their.geometr.cal pr.per.ies, depth below sur.ace and state of in-situ str.ss field. The objective of this paper.is to investigate the behaviour.of deep under.r.und tunnel opening existed between two bedding planes, Such planes weaken the str.ngth of r.ck mass and may cause r.ck slippage/r.tation along them. Ther.for., the state of str.ss-displacement, after.tunnel opening has been intr.duced, is examined using two-dimensional elasto-plastic finite-elements code, r.^(2D). The r.sults indicate that, ther. is significant dr.p in the nor.al str.ss along joints over.tunnel opening; slip occur. due to r.ver.al in the dir.ction of shear.str.ss(e.g., inwar. shear.displacement is pr.duced) and ther. is discontinuity in the str.ngth contour. of r.ck sur.ounding tunnel after.they have been inter.ected by bedding planes.

关键词： State of str.ss-displacement Bedding planes Tunnel per.or.ance Depth of failur. zones Stability analysis

Effect of induced shielding cur.ent tr.nsmission in longitudinal dir.ction on levitation for.e of melt gr.wn single-domain YBa_2Cu_3O_(7-x) cylindr.cal super.onductor

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Science China(Physics,Mechanics & Astr.nomy) 2004年第2期47卷 146-153页

作者： r. Nicolsky r. de Andr.de Jr LASUP-DEE UFRJ Ilha do Fundao Cx.P.68515 21945-970 Rio de Janeiro RJ Brasil Correspondence should be addressed to Yang Wanmin LASUP-DEE UFRJ Ilha do Fundao Cx.P.68515 21945-970 Rio de Janeiro RJ Brasil Correspondence should be addressed to Yang Wanmin

A novel layer.deletion method is used to exper.mentally investigate the effect of induced shielding cur.ent tr.nsmission (ISCT) in the longitudinal dir.ction on the levitation for.e of a single-domain YBa2Cu3O7?x (YBCO) cylindr.cal super.onductor.(?30×7 mm). In the exper.ment the sample was gr.dually sliced into two equal sheets, at the middle height along a diameter.with 5 mm ever. step. The exper.mental r.sults show that the levitation for.e is closely r.lated with the ISCT in the longitudinal dir.ction. Any layer.deletion, even a small piece of layer.deletion can r.duce the levitation for.e of the sample. After.the whole layer.was deleted the levitation for.e can diminish about 50%. It is also found that the levitation for.e is dir.ctly pr.por.ional to the effective factor.of sur.ace ar.a, which is equal to the top sur.ace ar.a divided by the total sur.ace ar.a par.llel to the top sur.ace of the sample.

关键词： melt gr.wth, single domain YBCO, levitation for.e, induced cur.ent distr.bution.

Novel acid initiator. for.the r.pid cationic polymer.zation of styr.ne in r.om temper.tur. ionic liquids

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Science China Chemistr. 2012年第8期55卷 1671-1676页

作者： VIJAYAr.GHAVAN r. MACFAr.ANE D. r. Depar.ment of Chemistr. Monash University Clayton Campus Victoria 3800 Australia

Cationic polymer.zation of styr.ne has been achieved using sever.l novel acidic initiator. in r.om temper.tur. ionic liquids (ILs) under.mild r.action conditions to obtain polymer. of low molecular.weight with nar.ow polydisper.ity. Both str.ng pr.tic acids such as bis(tr.fluor.methanesulfonyl) amide acid (HTFSA) and a moder.tely weak acid such as bisoxalato phosphor.us acid (HBOP) have been studied as initiator.. It has been obser.ed that HTFSA initiates the polymer.zation r.pidly even at r.om temper.tur. and below, as compar.d to HBOP which pr.duces a slower.polymer.zation r.quir.ng elevated temper.tur.s to complete. The r.lative differ.nce in r.activity of the initiator. as compar.d to the pr.viously descr.bed HBOB initiator.is discussed in ter.s of the differ.nce in their.pr.ton acidity and the consequential basicity of the anions. The efficiency of differ.nt ILs as the r.action solvent is also pr.sented.

关键词： cationic polymer.zation HTFSA HBOP ILs polydisper.ity

Homogenization Theor. for.a r.plenishing Passive Scalar.Field

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Chinese Annals of Mathematics,Ser.es B 2009年第5期30卷 631-644页

作者： Peter.r. Kr.MEr.Shane r. KEATING Depar.ment of Mathematical Sciences Rensselaer Polytechnic Institute Center.for.Atmospher.-Ocean Science Courant Institute of Mathematical SciencesNew York University

Homogenization theor. pr.vides a r.gor.us fr.mewor. for.calculating the effective diffusivity of a decaying passive scalar.field in a tur.ulent or.complex *** author. extend this fr.mewor. to the case wher. the passive scalar.fluctuations ar. continuously r.plenished by a sour.e (and/or.sink).The basic str.ctur. of the homogenized equations car.ies over.but in some cases the homogenized sour.e can involve a non-tr.vial coupling of the velocity field and the *** author. der.ve expr.ssions for.the homogenized sour.e ter. for.var.ous multiscale sour.e str.ctur.s and inter.r.t them physically.

关键词： Homogenization Tur.ulent tr.nspor. Sour.e Pumping

Soil Wettability as Affected by Soil Char.cter.stics and Land Use

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Pedospher. 2010年第1期20卷 43-54页

作者： r. HOr. Institute of Plant Nutr.tion and Soil Science Christian-Albrechts-University zu Kiel

Depth distr.bution of soil wettability and its cor.elations with vegetation type, soil textur., and pH wer. investigated under.var.ous land use (cr.pland, gr.ssland, and for.stland) and soil management systems. Wettability was evaluated by contact angle with the Wilhelmy plate method. Water.r.pellency was likely to be pr.sent under.per.anently vegetated land, but less common on tilled agr.cultur.l land. It was mostly pr.valent in the topsoil, especially in coar.e-textur.d soils, and decr.ased in the subsoil. However. the depth dependency of wettability could not be der.ved fr.m the investigated wide r.nge of soils. The cor.elation and multiple r.gr.ssion analysis r.vealed that the wettability in r.pellent soils was affected mor. by soil or.anic car.on (SOC) than by soil textur. and pH, wher.as in wettable soils, soil textur. and pH wer. mor. effective than SOC. Fur.her.or., the quality of SOC seemed to be mor. impor.ant in deter.ining wettability than its quantity, as pr.ofed by str.nger.hydr.phobicity under.conifer.us than under.deciduous for.stland. Soil management had a minor.effect on wettability if conventional and conser.ation tillage or.differ.nt gr.zing intensities wer. consider.d.

关键词： soil management soil or.anic car.on soil pH soil textur.

Numer.cal Investigation of Tip Clear.nce Effects in an Axial Tr.nsonic Compr.ssor

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Jour.al of Ther.al Science 2012年第2期21卷 109-119页

作者： r. Cior.iar. A. Lesser.F. Blaim r. Niehuis Institute for.Jet Pr.pulsion University of Federal Armed Forces Munich Werner-Heisenberg-Weg 39 D-85577 Neubiberg

Numer.cal investigations of the Dar.stadt tr.nsonic single stage compr.ssor.(DTC), in the r.tor.-Stator. configur.tion, aimed at advancing the under.tanding of the effect of differ.nt r.tor.tip gaps and tr.nsition modelling on the blade sur.aces ar. pr.sented. Steady thr.e dimensional r.ynolds Aver.ged Navier.Stokes (r.NS) simulations wer. per.or.ed to obtain the flow fields for.the differ.nt configur.tions at differ.nt oper.ting conditions using the r.NS-Solver.Tr.CE. The stage geometr. and the multi-block str.ctur.d gr.d wer. gener.ted by G3DMESH and a gr.d sensitivity analysis was conducted. For.the clear.nce gap r.gion, a fully gr.dded special H-gr.d was chosen. Compar.sons wer. made between the flow char.cter.stic at design speed, r.pr.sentative for.a tr.nsonic flow r.gime, and at 65% speed, r.pr.sentative for.a subsonic flow r.gime. The computations wer. used to analyse the flow phenomena thr.ugh the tip clear.nce r.gion for.the differ.nt configur.tions and their.impact on the per.or.ance of the compr.ssor.stage.

关键词： Flow in axial compr.ssor sur.e and stall tip clear.nce flow multimode tr.nsition model.

Inhomogeneous 2D Lennar.-Jones Fluid: Theor. and Computer.Simulation

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Communications in Theor.tical Physics 2012年第11期58卷 759-764页

作者： r. Khor.ad Depar.ment of Physics College of SciencesYasouj University

In this wor., ther.odynamical pr.per.ies of a two-dimensional （21）） Lennar.-Jones （L J） fluid ar. studied. Her., to incr.ase the accur.cy of our.theor.tical calculations, the cor.elation functions in thr.e-par.icle level （tr.plet） ar. applied. To obtain the tr.plet cor.elation functions, the Attar.＇s sour.e par.icle method is extended to 21） systems. In the Attar.＇s pr.cedur., the inhomogeneous Or.stein Zer.ike （OZ） equation is solved using the Tr.izenber. Zwanzwig （TZ） expr.ssion and a closur. r.lation like the hy2er.etted-chain （HNC） appr.ximation. In the pr.sent wor., we also have per.or.ed the Monte Car.o （MC） simulation. The theor.tical r.sults ar. in fair.y agr.ement with the MC simulation. Also, our.r.sults show that the appr.ach pr.posed her. is suitable to study the 2D LJ fluid.

关键词： Lennar.-Jones fluid cor.elation functions computer.simulation thr.e-par.icle level