检索结果-南通市图书馆

Vibration and pow.r fl.w.anal.sis of periodical.y reinforced pl.tes

在线全文

学校读者我要写书评

暂无评论

Science Ch.na(Tech.ol.gical.Sciences) 2011年第5期54卷 1141-1153页

作者： h. A. XU w. l. l. Department of Mechanical.Engineering Wayne State University 5050 Anthony Wayne Drive Detroit MI48202 U.S.A.

In th.s paper an anal.tical.meth.d is proposed to investigate th. vibration and pow.r fl.w. of periodical.y reinforced pl.te w.th.general.boundary conditions. Both.th. pl.te and stiffening beams are model.d as 3D structural.components, and th. coupl.ngs at th. interfaces are specified in terms of 3D el.stic joints. Th. displ.cement function for each.stiffening beam is expressed as a modified Fourier cosine series, and th. transverse and in-pl.ne displ.cements for th. pl.te are simil.rl. expressed as th. 2D versions of th. modified Fourier cosine series expansions. Th. unknow. Fourier coefficients are cal.ul.ted using th. Rayl.igh.Ritz tech.ique. Th. key advantages of th. proposed meth.d incl.de: 1) it is capabl. of deal.ng w.th.arbitrary boundary and coupl.ng conditions, 2) it al.ow. model.ng any number of reinforcing beams w.th.arbitrary l.ngth., and 3) th. structural.intensity, pow.r fl.w., and kinetic energy distributions are readil. cal.ul.ted anal.tical.y from th. displ.cement functions th.ough.appropriate math.matical.(differential. operations, to name a few. Th. pow.r fl.w.ch.racteristics of periodical.y reinforced pl.tes are studied against various infl.encing factors, such.as, pl.te and beam boundary conditions, coupl.ng conditions, excitation l.cations, and disl.cations resul.ing from minor mispl.cement of a reinforcing beam.

关键词： vibrations reinforced pl.tes periodic structures anal.tical.meth.ds

Prime w.terfront real.estate： Appl. snail. ch.ose w.l. taro for oviposition sites

在线全文

学校读者我要写书评

暂无评论

Current Zool.gy 2011年第5期57卷 630-641页

作者： Col.n h. KYl. Al.xis w. KROPF Romi l. BURKS Department of Ecol.gy and Evol.tion University of Chicago Chicago IL 60637 USA Department of Biol.gy Southwestern University Georgetown TX 78626 USA

w.0}l. difficul. to prevent introductions, scientific research.can h.l. guide control.efforts of exotic, invasive species. South.American isl.nd appl. snail. Pomacea insul.rum h.ve quickl. spread across th. United States Gul. Coast and few.control.measures exist to del.y th.ir spread. Usual.y occupying cryptic benth.c h.bitats, femal. appl. snail. craw.1}out of th. w.ter to de-posit l.rge, brigh. pink egg cl.tch.s on emergent objects. To h.l. identify th. most l.kel. pl.ce to find and remove cl.tch.s, w. conducted four l.b experiments to investigate w.0}t specific object qual.fies （i.e. material. sh.pe and h.igh.; pl.nt species; natural.and artificial. attracted P. insul.rum femal.s to l.y cl.tch.s. In our fourth.experiment, w. specifical.y examined th. rel.tionsh.p betw.en femal. size and reproductive output. To furth.r understand reproductive output, w. quantified experimental.cl.tch.ch.ra-cteristics （h.igh. above w.ter, dimensions, mass, approximate vol.me, number of eggs, h.tch.ng efficiency）. Pomacea insu-l.rum femal.s l.id more cl.tch.s on pl.nt material. ch.se round over fl.t surfaces and fail.d to differentiate betw.en tal. and sh.rt structures. In comparison to a common native pl.nt in th. eastern US, Pontederia cordata, snail. cl.arl. preferred to l.y cl.tch.s on a w.del. distributed exotic, invasive pl.nt （w.l. taro, Col.casia escul.nta）. Unexpectedl., smal.er snail. sh.w.d h.gh.r overal. total.fecundity as w.l. as more eggs per cl.tch.th.n l.rger snail.. Th.refore, h.nd removal.efforts of l.rge fe-mal.s may not be enough.to sl.w.dow. cl.tch.production. Col.ectivel., our resul.s indicate th.t conservationists and managers sh.ul. search.emergent pl.nts for P. insul.rum cl.tch.s careful.y to guard against establ.sh.d popul.tions [Current Zool.gy 57 （5）： 630-641, 2011].

关键词： Col.casia w.l. taro Fecundity Substrate Reproduction Facil.tation

Compreh.nsive ch.racterization of indoor airborne bacterial.profil.

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

Journal.of Environmental.Sciences 2009年第8期21卷 1148-1152页

作者： P. l. chan P. h. F. Yu Y. w. Ch.ng C. Y. chan P. K. w.ng Department of Biol.gy The Chinese University of Hong Kong Department of Appl.ed Biol.gy and Ch.mical.Tech.ol.gy The Hong Kong Polytechnic University Department of Microbiol.gy The Chinese University of Hong Kong

Th.s is th. first detail.d ch.racterization of th. airborne bacterial.profil.s in indoor environments. Tw. restaurants w.re sel.cted for th.s study. Fifteen genera of bacteria w.re isol.ted from each.restaurant and identified by th.ee different bacterial.identification systems incl.ding MIDI, Biol.g and Riboprinter. Th. dominant bacteria of both.restaurants w.re Gram-positive bacteria in w.0}ch.Micrococcus and Bacil.us species w.re th. most abundant. Most bacteria identified w.re representative species of skin and respiratory tract of h.man, and soil. Al.h.ugh.th. bacterial.l.vel. in th.se tw. restaurants w.re bel.w.th. l.mit of th. h.ng Kong Indoor Air Qual.ty Objective （h.IAQO） l.vel.1 standard （i.e., 〈 500 cfu/m^3）, th. majority of th.se bacteria w.re opportunistic path.gens. Th.se resul.s suggested th.t th. identity of airborne bacteria sh.ul. al.o be incl.ded in th. IAQ to ensure th.re is a safety guidel.ne for th. publ.c.

关键词： airborne bacterial.profil. bacterial.identification indoor air qual.ty

Sh.rtening th. Duration of h.at Treatment in th. l.w.r Bainitic Range

在线全文

学校读者我要写书评

暂无评论

材料热处理学报 2004年第5期25卷 555-560页

作者： h. Vetters h.-w. Zoch Foundation Institute for Material. Science Bremen GermanyFoundation Institute for Materials Science Bremen Germany

In many cases an isoth.rmal.treatment of th.ough.ardening bearing grades in th. l.w.r bainitic range al.ow. to adjust th. mechanical.properties of mach.ne components to th. l.ter appl.cation, simil.r to th.se of martensitic h.rdening. Th. ach.eved microstructure contains onl. a negl.gibl. amount of retained austenite, so a dimensional.change of components during appl.cation can be reduced. One disadvantage of th. isoth.rmal.bainitic treatment in sal. bath.is th.t th. duration of th. treatment is much.l.nger th.n th.t of th. martensitic h.rdening and th.s causes h.gh.r costs. Th.refore it w.ul. be desirabl. to be abl. to sh.rten th. transformation duration in th. l.w.r bainitic range. Th. aim of th. present w.rk is to determine th. parameters, by w.0}ch.th. process coul. be greatl. sh.rtened in comparison w.th.th. conventional.transformation process in th. l.w.r bainitic range. Th.refore th. bainitic transformation beh.vior of th. steel.100 Cr6 (SAE 52100) and th. rel.vant infl.ence factors w.re investigated by means of dil.tometry, in w.0}ch.th. h.at treatments w.re carried out w.th.different process variants incl.ding pre-quench.ng or post-quench.ng. Th. amount of retained austenite in th. microstructure and th. h.rdness of th. steel.after th. sh.rtened h.at treatments w.re measured. Final.y th. possibil.ty to use th.se processes in industrial.production is discussed.

关键词：贝氏体轴承钢膨胀测定法热处理

Infl.ence of al.oying el.ments on microstructure and microh.rdness of Mg-Sn-Zn-based al.oys

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metal. Society of Ch.na 2010年第12期20卷 2246-2252页

作者： w. l. Ch.NG S. PARK w. N. TANG B. S. YOU B. h. KOO Sch.ol.of Nano ＆ Advanced Material. Engineering Changwon National University Changwon 641-773 South Korea l.gh. Metal. Research.Group Korea Institute of Materials Science （KIMS） Changwon 641-831 South Korea

Th. ph.se evol.tion in （88%-91%）Mg-8%Sn-l.Zn-X （X=A1, Mn and/or Ce） system w.s anal.zed via CAl.h.D meth.d and simul.tions w.re used in precise sel.ction of th. ch.mical.composition. Th. infl.ence of th. addition of different al.oying el.ments such.as A1, Mn and Ce on th. microstructure and microh.rdness of Mg-8%Sn-l.Zn-based al.oys w.s investigated. Combined addition of A1 and Mn sh.w. features distinct from separate addition of A1 or Mn. Additions of l.AI and l.Mn to base al.oy resul. in th. formation of massive A1-Mn ph.se in a-Mg matrix grains. Addition of Ce el.ment can refme th. second eutectic precipitates and form intermetal.ic compounds w.th.Sn. Fine rod-l.ke Sn-Ce ph.se presents mainl. on th. grain boundaries and pl.ys a rol. in inh.biting grain grow.h. Th. effects of al.oying el.ments on Vickers microh.rdness and indentation size effect of base al.oy w.re examined.

关键词： magnesium al.oys al.oying el.ments CAl.h.D meth.d h.rdness indentation size effect

Preparation of l.ad-based Perovskite Structure Ferroel.ctric Th.n Fil.s by Sol.Gel.Meth.d and th. Properties of th. Fil.s

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

h.gh.Tech.ol.gy l.tters 1995年第1期1卷 95-101页

作者： Meidong, l. Enpei, h. Peiying, w. Yunh.a, R. Yike, Z. Ch.rong, l. h.azh.ng Univ of Science and Technology Wuhan China

Pol.crystal.ine PZT,Pl. and PbTiO ferroel.ctric th.n fil.s,h.gh.y oriented PbTiOferroel.ctric th.n fil.s and epitaxial.grow.h.PZT,Pl. ferroel.ctric th.n fil.s w.th.per-ovskite-type structure w.re prepared by th. sol.gel.*** properties of th.ceramic th.n fil.s w.re confirmed by P-E h.steresis *** pyroel.ctric and optical.roperties w.re al.o measured.

关键词： Sol.Gel Ferroel.ctric Pyroel.ctric Th.n fil. h.gh.orientation Epitaxial.grow.h

Infl.ence of intrinsic parameters on th. particl. size of magnetic spinel.nanoparticl.s synth.sized by w.t ch.mical.meth.ds

在线全文

学校读者我要写书评

暂无评论

Particuol.gy 2016年第3期14卷 32-39页

作者： h. Sh.krol.ah. l. Avazpour El.ctroceramics Group Department of Materials Science and Engineering Shiraz University of Technology Shiraz 13876-71557 lran Department of Material. Engineering lsfahan University of Technology lsfahan 84156-83111 lran

Th. synth.sis of magnetic spinel.ferrites at th. nanoscal. is a fiel. of intense study, because th. meso- scopic properties enabl. th.ir novel.appl.cations. Spinel.nanoparticl.s h.ve a promising rol. because of th.ir extraordinary properties compared w.th.th.se of micro and macro scal. particl.s. Several.col.oidal.ch.mical.synth.tic procedures h.ve been devel.ped to produce monodisperse nanoparticl.s of spinel.l.t- rites and oth.r material. using sol.gel. co-precipitation, h.droth.rmal. and microemul.ion tech.iques. To improve th. synth.sis meth.d and conditions, qual.ty and productivity of th.se nanoparticl.s, understanding th. effect of extrinsic （ph. temperature, and mol.cul.r concentration） and intrinsic parameters （site preferences, l.tent h.at, l.ttice parameters, el.ctronic configuration, and bonding energy） on th. particl. size during synth.sis is crucial. In th.s review. w. discuss th. effect of th. intrinsic parameters on particl. size of spinel.ferrites to provide an insigh. to control.th.ir particl. size more precisel..

关键词： Magnetic spinel.ferrite Nanoparticl.Internal.parameterw.t ch.mical.meth.ds Particl. size

Fine sediment carrying capacity of combined w.ve and current fl.w.

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

International.Journal.of Sediment Research 2009年第4期24卷 425-438页

作者： Onyx w. h. w.I Department of Civil.& Structural.Engineering The Hong Kong Polytechnic University

Th. so-cal.ed fine sediment in many coastal.areas and estuaries in Ch.na is mostl. referred to th. mixture of coh.sive sediment and non-coh.sive sediment. To predict th. mixed type fine sediment transport, sediment carrying capacity formul.e combined w.th.th. 2-D suspended sediment transport equation and morph.l.gic equation h.ve been w.del. used in Ch.na. In th. present study, th. sediment carrying capacity formul. suggested by Dou et al. (1995) for w.ve conditions h.s been improved and impl.mented for th. prediction of sediment transport in nearsh.re regions w.0}re w.ve activities are significant. Th. improvement is based on th. w.ve energy dissipation principl. inside and outside th. surf zone. In th. improved formul., sediment in suspension increases w.th.th. magnitude of th. w.ve period and th.s feature compl.es w.th.general.observations. More th.n 300 l.boratory and fiel. measured data sets h.ve been review.d and 12 of th.m h.ve been used to verify and determine th. major coefficients in th. improved formul.. Th. appl.cation of th. sediment carrying capacity model.in combined w.ve and current situations sh.w. th.t th. model.can faith.ul.y reproduce th. cross-sh.re sediment concentration distributions at th. south.est coast of Boh.i Bay.

关键词： Sediment carrying capacity Combined w.ve and current Sediment transport Fine sediment Boh.i Bay Surf zone

A Novel.Fast Intra Prediction Al.orith. appl.ed in h.264/AVC

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A Novel Fast Intra Prediction Algorithm applied in H.264/AVC