检索结果-南通市图书馆

a.structura. topologica. optimiza.ion meth.d for multi-displa.ement constra.nts a.d a.y initia. topology configura.ion

在线全文

学校读者我要写书评

暂无评论

a.ta.Mech.nica.Sinica 2010年第5期26卷 735-744页

作者： j. h. Rong j. h. Yi Sch.ol of a.tomotive a.d Mech.nica. Engineering Changsha University of Science and TechnologyChangsha 410076 China

In density-ba.ed topologica. design, one expects th.t th. fina. result consists of elements eith.r bla.k （solid ma.eria.） or wh.te （void）, with.ut a.y grey a.ea.. Moreover, one a.so expects th.t th. optima. topology ca. be obta.ned by sta.ting from a.y initia. topology configura.ion. a. improved structura. topologica. optimiza.ion meth.d for multidispla.ement constra.nts is proposed in th.s pa.er. In th. proposed meth.d, th. wh.le optimiza.ion process is divided into two optimiza.ion a.j.stment ph.ses a.d a.ph.se tra.sferring step. Firstly, a. optimiza.ion model is built to dea. with.th. va.ied displa.ement limits, design spa.e a.j.stments, a.d rea.ona.le rela.ions between th. element stiffness ma.rix a.d ma.s a.d its element topology va.ia.le. Secondly, a.procedure is proposed to solve th. optimiza.ion problem formula.ed in th. first optimiza.ion a.j.stment ph.se, by sta.ting with.a.sma.l design spa.e a.d a.va.cing to a.la.ger deign spa.e. Th. design spa.e a.j.stments a.e a.toma.ic wh.n th. design doma.n needs expa.sions, in wh.ch.th. convergence of th. proposed meth.d will not be a.fected. Th. fina. topology obta.ned by th. proposed procedure in th. first optimiza.ion ph.se, ca. a.proa.h.to th. vicinity of th. optimum topology. Th.n, a.h.uristic a.gorith. is given to improve th. efficiency a.d ma.e th. designed structura. topology bla.k/wh.te in both.th. ph.se tra.sferring step a.d th. second optimiza.ion a.j.stment ph.se. a.d th. optimum topology ca. fina.ly be obta.ned by th. second ph.se optimiza.ion a.j.stments. Two exa.ples a.e presented to sh.w th.t th. topologies obta.ned by th. proposed meth.d a.e of very good 0/1 design distribution property, a.d th. computa.iona. efficiency is enh.nced by reducing th. element number of th. design structura. finite model during two optimiza.ion a.j.stment ph.ses. a.d th. exa.ples a.so sh.w th.t th.s meth.d is robust a.d pra.tica.le.

关键词： Topologica. optimiza.ion Displa.ement constra.nt Continuum structure Design spa.e a.j.stment Ra.iona. a.proxima.ion ma.eria. model

Multimedia.model of a.ra.ine in pla.t-soil-groundwa.er system with.a.fuga.ity a.proa.h

在线全文

学校读者我要写书评

暂无评论

j.urna. of Environmenta. Sciences 2001年第4期13卷 466-471页

作者： Ye, C.-m. Lei, Z.-f. Wa.g, X.-j. Gong, a.-j. Zh.ng, h.-h. Res. Cntr. Eco-Environmenta. Sci. Chinese Academy of Sciences Beijing 100085 China

Th. a.plica.ion of a.ra.ine in Ch.na.during th. la.t ten yea.s h.s led to some environmenta. problems. In th.s pa.er, th. multimedia.model of a.ra.ine in soil-pla.t-groundwa.er system a. Ba.ya.gdia. La.e a.ea.in North.rn Ch.na.wa. esta.lish.d using a.fuga.ity a.proa.h. a.d verified with.observed va.ues. Th. model involved 7 environmenta. compa.tments wh.ch.a.e a.r, groundwa.er, soil, corn roots, corn stem, corn lea. a.d kernel of corn. Th. results sh.wed th.t th. rela.ive errors between ca.cula.ed a.d observed va.ues h.ve a.mea. va.ue of 24.7%, th. h.gh.st va.ue is 48% a.d th. lowest va.ue is 1.4%. a.l th.se va.ues indica.ed th.t th.s multimedia.model ca. be used to simula.e th. environmenta. fa.e of a.ra.ine. Both.th. ca.cula.ed a.d observed va.ues of concentra.ions of a.ra.ine in pla.t compa.tments a.e in th. following order: in corn roots > in corn stem > in kernel of corn > in corn lea., it exh.bited a.good regula.ity. Th. prediction results indica.ed th.t concentra.ions of a.ra.ine in th. groundwa.er a.d kernel of corn will override th. limita.ion of 3 μg/L a.d 0.05 mg/kg respectively.

关键词： Concentra.ion (process) Error detection Groundwa.er La.es Pla.ts (bota.y) Soils

a.genera.iza.ion of （G＇/G）-expa.sion meth.d a.d its a.plica.ion to nonlinea. rea.tion-diffusion equa.ions a.ising in ma.h.ma.ica. biology

在线全文

学校读者我要写书评

暂无评论

Interna.iona. j.urna. of Bioma.h.ma.ics 2014年第3期7卷 41-50页

作者： a. j.bba.i j. Ma.a.ia. h.ris h. Kh.iri a. Bekir Depa.tment of a.plied Ma.h.ma.ics University of Tabriz 29 Bahman St. Tabriz-Iran Ma.h.ma.ics a.d Computer Sciences Depa.tment Eskiseh.r Osma.ga.i University 26480 Eskiseh.r Turkey

In th.s pa.er, by introducing a.proper tra.sforma.ion, th. （Gr/G）-expa.sion meth.d is furth.r extended into th. nonlinea. rea.tion diffusion equa.ions in ma.h.ma.ica. biology wh.se ba.a.cing numbers ma. be nega.ive integer. a. a.result, h.perbolic function solutions a.d trigonometric function solutions with.free pa.a.eters a.e obta.ned. Wh.n th. pa.a.eters a.e ta.en a. specia. va.ues th. solita.y wa.e solutions a.d th. periodic wa.e solutions a.e a.so derived from th. tra.eling wa.e solutions. Moreover, it is observed th.t th. suggested tech.iques is compa.ible of such.problems.

关键词： Genera.ized (GI/G)-expa.sion meth.d exa.t solutions nonlinea. rea.tion-diffusion equa.ions.

a.oustic Mea.urements for Determina.ion of th. Ma.eria.s Da.ping Using a.Sound Source Loca.isa.ion System

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

a.ta.Meta.lurgica.Sinica.English.Letters) 2013年第2期26卷 113-121页

作者： j. Gken j. Swiostek h. h.rdelbrink U. Keil Fa.ulty of Ma.itime Studies University of Applied Sciences Emden/Leer Bergmannstr. 36 26789 LeerGermany Sta.oma. TM Company of High-Precision Mechanics ul. Parkingowa 45 37450 Stalowa WolaPoland

Noise mea.urements a.e especia.ly a.problem wh.n th. obj.ct under investiga.ion is la.gely dimensioned a.d ca. only be mea.ured from th. dista.ce. To obta.n informa.ion a.out th. loca.ion of noise genera.ion, a.mea.urement tech.ique wh.ch.ma.es sound visible in order to introduce furth.r specific tech.ica. mea.ures is a.va.ta.eous. Th. question is if th. time dependence of th. signa. got from such.a.non touch.ng a.d non destructive a.oustic meth.d h.s th. potentia. to ca.cula.e th. ma.eria.s da.ping from. Using a.sma.l sound source loca.iza.ion system （Microflown^TM probe）, specimens of ma.nesium a.loys with.different gra.n sizes obta.ned by h.drosta.ic extrusion were investiga.ed. It h.s been demonstra.ed th.t th. fine gra.ned microstructure led to a.lower da.ping a.d its dependence on th. stra.n wa. reduced. In th.s context, a.oustic mea.urements by a.sound source loca.isa.ion system wh.ch.ma.es ma.eria.s ch.ra.teriza.ion possible could be used a. a.qua.ity tool to detect ch.nges in h.gh.y stressed components. Th.s a.proa.h.a.lows to promote a.selective substitution of conventiona. ma.eria.s by more innova.ive ones. Th. offsh.re sector is considered to be a.field of a.plica.ion： Wind turbines produce noise emission wh.ch.stems ma.nly from turbulences a. th. tips of th. rotor bla.es a.d vibra.ions of components inside th. na.elle （e.9. gea.box, genera.or, ...）. If th. vibra.ion a.plitudes a.e too h.gh. microcra.ks of components ca. lea. to fa.lure over th. long term. Th. monitoring of microstructura. ch.nges using a.la.ger type of a.sound source loca.isa.ion system is considered a. a. innova.ive tech.ica. a.proa.h.with.respect to ma.ntena.ce a.tivities.

关键词： Ma.nesium Noise mea.urements MicroflownTM Da.ping

Simula.ing ca.opy stoma.a. conducta.ce of winter wh.a. a.d its distribution using remote sensing informa.ion

在线全文

学校读者我要写书评

暂无评论

j.urna. of Environmenta. Sciences 2001年第4期13卷 439-443页

作者： Zh.ng, j.-h. Fu, C.-b. Ka.za.a. h. STa.T Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Th. ca.opy stoma.a. movement, a.pla.t ph.siologica. process, genera.ly occurs with.n lea.es but its influence on exch.nge of CO2, wa.er va.or, a.d sensible h.a. fluxes between a.mosph.re a.d terrestria. ecosystem. Ma.y studies h.ve documented th.t th. intera.tion between lea. ph.tosynth.sis a.d ca.opy stoma.a. conducta.ce is obvious. Th.s, informa.ion on stoma.a. conducta.ce is va.ua.le in clima.e a.d ecosystem models. In current study, a.newly developed model wa. a.opted to ca.cula.e ca.opy stoma.a. conducta.ce of winter wh.a. in h.a.g-h.a.-h.i (h.h.h. Pla.n of Ch.na.(31.5 - 42.7°N, 110.0 - 123.0°E). Th. remote sensing informa.ion from NOa.-a.h.R a.d meteorologica. observed da.a.were used to estima.e regiona. sca.e stoma.a. conducta.ce distribution. Ca.opy stoma.a. conducta.ce distribution pa.tern of winter wh.a. on Ma.ch.18, 1997 wa. a.so presented. Th. developed ca.opy stoma.a. conducta.ce model migh. be used to estima.e ca.opy stoma.a. conducta.ce in la.d surfa.e sch.mes a.d seems ca. be a.ted a. a.bounda.y condition in regiona. clima.ic model runs.

关键词： Ca.bon dioxide Da.a.reduction Ecosystems h.a. flux Meteorology Ph.tosynth.sis Ph.siology Pla.ts (bota.y) Remote sensing Va.ors

Exa.t solution a.d tra.sient beh.vior for torsiona. vibra.ion of functiona.ly gra.ed finite h.llow cylinders

在线全文

学校读者我要写书评

暂无评论

a.ta.Mech.nica.Sinica 2009年第4期25卷 555-563页

作者： h. M. Wa.g C. B. Liu h. j. Ding Depa.tment of Mech.nics Zhejiang University Depa.tment of Civil Engineering Zhejiang University

Exa.t solutions a.e obta.ned for tra.sient torsio- na. responses of a.finitely long, functiona.ly gra.ed h.llow cylinder under th.ee different end conditions, i.e. free-free, free-fixed a.d fixed-fixed. Th. cylinder with.its externa. surfa.e fixed is subj.cted to a.dyna.ic sh.a.ing stress a. th. interna. surfa.e. Th. ma.eria. properties a.e a.sumed to va.y in th. ra.ia. direction in a.power la. form, wh.le keep inva.ia.t in th. a.ia. direction. With.expa.sion in th. a.ia. direction in terms of trigonometric series, th. governing equa.ions for th. unknown functions a.out th. ra.ia. coordina.e r a.d time t a.e deduced. By a.plying th. va.ia.le substitution tech.ique, th. superposition meth.d a.d th. sepa.a.ion of va.ia.les consecutively, series-form solutions of th. equa.ions a.e obta.ned. Na.ura. frequencies a.d th. tra.sient torsiona. responses a.e fina.ly discussed for a.functiona.ly gra.ed finite h.llow cylinder.

关键词： Exa.t solution Functiona.ly gra.ed ma.eria. Finite h.llow cylinder Tra.sient torsiona. vibra.ion

SIMILa.ITY SOLUTIONS FOR VISCOUS Ca.ITa.ING VORTEX CORES

在线全文

学校读者我要写书评

暂无评论

j.urna. of h.drodyna.ics 2008年第6期20卷 679-688页

作者： BOSSCh.RS j.j.NSSEN a. a. h.EIj.a.ERS h. W. M. Ma.itime Resea.ch.Institute Neth.rla.ds (Ma.IN) P.O. Box 28 6700 AA Wageningen The Netherlands University of Twente Enschede The Netherlands

Th.oretica. a.a.ysis of th. dyna.ic beh.vior of ca.ita.ing vortices requires knowledge of th. velocity distribution in th. vortex core. For th.t rea.on a. existing simila.ity model for slender a.isymmetric non-ca.ita.ing vortex cores h.s been extended with.th. viscous bounda.y conditions for a.ca.ita.ing vortex. Ca.ita.ing simila.ity solutions exist for a.vortex of wh.ch.both.core dia.eter a.d circula.ion grow with.th. squa.e root of th. a.ia. coordina.e. Results for th.s model a.e presented for va.ying ca.ita.ion numbers a.d Reynolds numbers. It is sh.wn th.t viscosity ma. h.ve a.significa.t influence on th. velocity distribution a.ound a.ca.ita.ing vortex.

关键词： ca.ita.ion vortex viscous flow

h.brid finite-discrete element modelling of a.perity degra.a.ion a.d gouge grinding during direct sh.a.ing of rough.rock j.ints

在线全文

学校读者我要写书评

暂无评论

Interna.iona. j.urna. of Coa. Science & Tech.ology 2016年第3期3卷 295-310页

作者： h. Y. Liu h.oyu h.n h. M. a. j. j. Sh. Sch.ol of Engineering a.d ICT University of TasmaniaHobart TAS 7001 Australia Sch.ol of Civil & Environmenta. Engineering University ofScience and Technology Beijing Beijing China

a.h.brid finite-discrete element meth.d wa. implemented to study th. fra.ture process of rough.rock j.ints under direct sh.a.ing. Th. h.brid meth.d reproduced th. j.int sh.a. resista.ce evolution process from a.perity sliding to degra.a.ion a.d from gouge forma.ion to grinding. It is found th.t, in th. direct sh.a. test of rough.rock j.ints under consta.t norma. displa.ement loa.ing conditions, h.gh.r sh.a.ing ra.e promotes th. a.perity degra.a.ion but constra.nts th. volume dila.ion, wh.ch.th.n results in h.gh.r pea. sh.a. resista.ce, more gouge forma.ion a.d grinding, a.d smooth.r new j.int surfa.es. Moreover, it is found th.t th. j.int rough.ess a.fects th. j.int sh.a. resista.ce evolution th.ough.influencing th. j.int fra.ture micro mech.nism. Th. a.perity degra.a.ion a.d gouge grinding a.e th. ma.n fa.lure micro-mech.nism in sh.a.ing rough.r rock j.ints with.deeper a.perities wh.le th. a.perity sliding is th. ma.n fa.lure micro-mech.nism in sh.a.ing smooth.r rock j.ints with.sh.llower a.perities. It is concluded th.t th. h.brid finite-discrete element meth.d is a.va.ua.le numerica. tool better th.n tra.itiona. finite element meth.d a.d discrete element meth.d for modelling th. j.int sliding, a.perity degra.a.ion, gouge forma.ion, a.d gouge grinding occurred in th. direct sh.a. tests of rough.rock j.ints.

关键词： h.brid FEM-DEM Rock j.int a.perity sliding a.perity sh.a.ing Fra.ment grinding

Enzyma.ic oxida.ion of a.ueous penta.h.oroph.nol

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

j.urna. of Environmenta. Sciences 2007年第9期19卷 1032-1036页

作者： E. Y. Kim h. j. Ch.e K. h. Ch. Depa.tment of Ch.mica. Engineering The University of Seoul Seoul 130-743 Korea. Depa.tments of Food a.d Biotech.ology a.d Innova.ive Industria. Tech.ology Hoseo University Asan 336-795 Korea h.neywell Process Solutions 17 Changi Business Park Central 1 Singapore 486073

Th. influence of th. nonionic surfa.ta.t Tween 80 on penta.h.oroph.nol （PCP） oxida.ion ca.a.yzed by h.rsera.ish.peroxida.e wa. studied. Th. surfa.ta.t wa. tested a. concentra.ions below a.d a.ove its critica. micelle concentra.ion （CMC）. Enh.ncement of PCP remova. wa. observed a. sub-CMCs. Th. presence of Tween 80 in th. rea.tion mixture reduced enzyme ina.tiva.ion wh.ch.occurred th.ough.a.combina.ion of free ra.ica. a.ta.k a.d sorption by precipita.ed products. a.simple first-order model wa. a.le to simula.e time profiles for enzyme ina.tiva.ion in th. presence or a.sence of Tween 80. a. supra.CMCs, th. surfa.ta.t ca.sed noticea.le reductions in PCP remova., presuma.ly th.ough.micelle pa.titioning of PCP wh.ch.precluded th. h.droph.bic PCP molecule from intera.ting with.th. enzyme.

关键词： bioca.a.ysis h.rsera.ish.peroxida.e penta.h.oroph.nol surfa.ta.t