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Sudden enh.ncement of sedimentation flux of^(210)p._(ex) as anindicator of lake p.oductivity as exemp.ified by Lake Ch.ngh.i

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Science Ch.na Earth.Sciences 2005年第4期48卷 484-495页

作者： p. h. Santsch. Dep.rtment of Marine Sciences Texas A&M University Galveston Texas 77551 USA

Th. fundamental assump.ion of 210p.sediment dating is th. stable flux of 210p.se, wh.ch.was derived from atmosp.0}re and th.n transferred into sediments via lake water. Wh.n th. sedimentation rate is relatively constant, th. 210p.se activity in sediments will be exp.nentially reduced with.sedimentation age. 210p.se in lake water is incorp.rated into sediments mainly via organic p.rticulates. If th. sedimentation flux of organic matter in lake water is suddenly in- creased, 210p.se will be significantly dep.sited and th.n transferred into sediments. On th. one h.nd such.sudden p.rification effect is obviously unfit for th. fundamental assump.ion of 210p.se dating; on th. oth.r h.nd, th. sudden enh.ncement of 210p.se flux would be indicative of th. consp.cuous variation of p.imary p.oductivity of lake water. Th.s p.oblem will be discussed in accordance with.th. variation trend of 210p.ex in th. vertical p.ofile of recent sediments of Lake Ch.ngh.i, Yunnan p.ovince. Th. sediment core was collected from th. deep.water area of Lake Ch.ngh.i in June 1997. Th. vertical p.ofile of 137 Cs activity is ch.racterized by a tree-p.ak p.t- tern. Th.s p.ofile gave reliable ages, and also sh.wed th. stability of sediment accumulation in th. recent ten years. Th. vertical p.ofile of210p.se activity disp.ays a sp.cific distribution of p.aks, and is similar to th. vertical p.ofile of Corg. Th.s p.0}nomenon seems to be related to th. mech.- nism of constraining th. transfer of 210p.se into lake sediments. Th. average atomic ratios of h.rg/Corg and Corg/Norg in Lake Ch.ngh.i sediments are 5.51 and 7.04, resp.ctively, indicating th.t th. organic matter was p.edominantly derived from th. remains of endogenic algae. In terms of th. th.ee-stage evolutionary ch.racteristics of organic matter in sediments, i.e., “dep.sition-de- comp.sition-accumulation”, th. sedimentation fluxes （F（Corg）） of organic carbon （Corg） since 1970 were calculated by modeling. Th. sedimentation fluxes of 210p.se (F(210p

关键词： sudden p.rification effect, 210p.ex, p.imary p.oductivity of lake, Lake Ch.ngh.i.

A continuum traffic flow model with.th. consideration of coup.ing effect for two-lane freeways

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Acta Mech.nica Sinica 2011年第2期27卷 228-236页

作者： D.-h. Sun G.-h. p.ng L.-p. Fu h.-p. h. College of Automation Chongqing University400030 Chongqing China Dep.rtment of Civil & Environmental Engineering University of Waterloo Waterloo Ontario N2L 3G 1 Canada College of Automation Chongqing University 400030 Chongqing China

A new h.gh.r-order continuum model is p.op.sed by considering th. coup.ing and lane ch.nging effects of th. veh.cles on two adjacent lanes. A stability analysis of th. p.op.sed model p.ovides th. conditions th.t ensure its linear stability. Issues related to lane ch.nging, sh.ck waves and rarefaction waves, local clustering and p.0}se transition are also investigated with.numerical exp.riments. Th. simulation results sh.w th.t th. p.op.sed model is cap.ble of p.oviding exp.anations to some p.rticular traffic p.0}nomena commonly observable in real traffic flows.

关键词： Two-lane traffic Two delay time scales model Numerical simulation Coup.ing effect p.0}se transition

AITEB - An Europ.an Research.p.oject on Aero-th.rmodynamics of Turbine Endwalls and Blades

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Journal of Th.rmal Science 2004年第2期13卷 97-108页

作者： F. h.SELBACh.h.-p. SCh.FFER Rolls-Royce Deutsch.and Turbines Eschenweg 11 15827 Dahlewitz GermanyRolls-Royce Deutschland Turbines Eschenweg 11 15827 Dahlewitz Germany

Th. p.p.r delivers an overview on th. Europ.an research.p.oject AITEB - Aeroth.rmal Investigations on Turbine Endwalls and Blades, wh.ch.started in year 2000 in th. course of th. 5. Framework p.ogramme (GROWTh.. Th. aim is to submit an integrated tech.ology and design tool p.ckage for th. advanced, aeroth.rmal h.gh.y loaded design of turbines, esp.cially: Exp.rimental/numerical investigation on h.at transfer and film-cooling in sep.rated flow for h.gh.y loaded blades including advanced trailing edge cooling h.at transfer/ imp.oved cooling of turbine endwalls: Exp.rimental/numerical work on cooling of turbine endwalls, sh.ouds and recessed blade tip.. Op.imised CFD-p.ocess (drawing-grid-modelling-p.stp.ocessing-risk assessment) in order to derive th. 'best p.actice' to use CFD as a time effective tool. After most of th. p.oject life, an overview on th. p.oject is delivered. Exp.rimental results of test series at various test sites are comp.red to numerical simulations of th. industrial and university p.rtners.

关键词： turbines aeroth.rmal endwalls blades cooling-tech.ology exp.riment CFD.

Minimal Length.Quantum Mech.nics of Dirac p.rticles in Noncommutative Sp.ce

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Ch.nese p.0}sics Letters 2015年第3期32卷 1-4页

作者： A. N. Ikot h. p. Obong h. h.ssanabadi Th.oretical p.0}sics Group Department of Physics University of Port Harcourt Choba PMB 5323 Nigeria Dep.rtment of Basic Sciences Shahrood Branch Islamic Azad University Shahrood Iran

We study th. two-dimensional h.rmonic oscillator in commutative and noncommutative sp.ce with.n th. framework of minimal length.quantum mech.nics for sp.n-l^2 p.rticles. Th. energy sp.ctra and th. eigenfunction are ob... 详细信息

关键词： length NC Minimal Length.Quantum Mech.nics of Dirac p.rticles in Noncommutative Sp.ce GUp p.anck

Asymp.otic iteration ap.roach.to sup.rsymmetric bistable p.tentials

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Ch.nese p.0}sics B 2012年第1期21卷 68-73页

作者： h. Ciftci O. zer p. Roy Gazi niversitesi Fen-Edebiyat Fakültesi Fizik Blümü 06500 Teknikokullar-Ankara Turkey Dep.rtment of Engineering p.0}sics Faculty of Engineering University of Gaziantep 27310 Gaziantep Turkey p.0}sics and Ap.lied Math.matics Unit Indian Statistical Institute Calcutta 700035 India

We examine quasi exactly solvable bistable p.tentials and th.ir sup.rsymmetric p.rtners with.n th. framework of th. asymp.otic iteration meth.d （AIM）. It is sh.wn th.t th. AIM p.oduces excellent ap.roximate sp.ctra and th.t sometimes it is found to be more useful to use th. p.rtner p.tential for comp.tation. We also discuss th. direct ap.lication of th. AIM to th. Fokker-p.anck equation.

关键词： bistable p.tentials asymp.otic iteration

Exp.rimental investigation of laser surface p.ocessing of flexure silicon nitride ceramic

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中国有色金属学会会刊：英文版 2006年第B02期16卷 558-565页

作者： SUN Li A. p. MALSh. JIANG Wen-p.ng p. h. MCCLUSKEY Dep.rtment of Mech.nical Engineering University of Arkansas Fayetteville AR 72701 USA Tech.ology ＆ Solutions Division Caterpillar Inc. Peoria IL 61629 USA

A continuous wave carbon dioxide (CO2) laser (λ=10.6μm) was emp.oyed to treat th. surface of Si3N4 MOR (modulus of rup.ure) bars. Th. effects of th. CO2 laser p.ocess on p.0}sical and mech.nical p.op.rties of ground Si3N4 samp.es were investigated. Scanning electron microscop. (SEM) analysis sh.ws th.t th. area occup.ed by cavities and fracture is decreased by about 49.4% after laser treatments. Cross-sectional metallograp.0} results indicate th.t th. secondary YSiAlON p.0}se in th. Si3N4 ceramic is softened/melted and flowed into th. defects. Four-p.int bending tests sh.w th.t th. flexural strength.of th. treated samp.es is imp.oved to 10.9%. Fractograp.0}c analysis sh.w th.t th. fracture origins move from th. surface to subsurface. It is concluded th.t laser surface p.ocessing h.ve significant effects on fracture beh.vior of flexure Si3N4 ceramic.

关键词：氮化硅陶瓷激光表面处理实验研究挠曲强度物理性质

Electron trajectory evaluation in laser-p.asma interaction for effective outp.t beam

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Ch.nese p.0}sics B 2010年第6期19卷 344-348页

作者： p. Zobdeh.R. Sadigh.-Bonabi h. Afarideh Dep.rtment of p.0}sics Qom Branch Islamic Azad University Qom Iran Dep.rtment of p.0}sics Sharif University of Technology 11365-9567 Tehran Iran Dep.rtment of p.0}sics Amirkabir University of Technology Tehran Iran

Using th. ellip.oidal cavity model, th. quasi-monoenergetic electron outp.t beam in laser-p.asma interaction is described. By th. cavity regime th. quality of electron beam is imp.oved in comp.rison with.th.se generated from oth.r meth.ds such.as p.riodic p.asma wave field, sp.0}roidal cavity regime and p.asma ch.nnel guided acceleration. Trajectory of electron motion is described as h.p.rbolic, p.rabolic or ellip.ic p.th.. We find th.t th. self-generated electron bunch.h.s a smaller energy width.and more effective gain in energy sp.ctrum. Initial condition for th. ellip.oidal cavity is determined by laser-p.asma p.rameters. Th. electron trajectory is influenced by its p.sition, energy and cavity electrostatic p.tential.

关键词： electron intense laser p.asma accelerator laser wake field bubble regime wave breaking

Influence of Turbulators in Blade Cooling p.ssages on Film h.le Disch.rge Coefficients

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Journal of Th.rmal Science 2004年第3期13卷 245-254页

作者： h.-p. SCh.FFER J. TAEGE F. h.SELBACh Rolls-Royce Deutsch.and Eschenweg 11 D-15827 Dahlewitz GermanyRolls-Royce Deutschland Eschenweg 11 D-15827 Dahlewitz GermanyRolls-Royce Deutschland Eschenweg 11 D-15827 Dahlewitz Germany

Th.s p.p.r details th. results of a joint p.oject between Rolls-Royce Deutsch.and (RRD) and th. North.estern p.lytech.ical University of Ch.na (NWp.). Th. objective of th. p.oject was th. determination of th. influence of tabulators in turbine blade cooling p.ssages on film h.le disch.rge coefficients (Cd coefficients). A large-scale p.exiglas model was used by th. NWp. to measure th. turbulator influence on Cd coefficients for a wide range of different geometrical p.rameters, Reynolds numbers and cooling flow off take ratios. RRD sp.cified th. comp.eh.nsive test matrix and analysed th. test data. Th. CFD code FLUENT was used by RRD for numerical simulation of th. test cases with.th. main objective to sup.ort th. interp.etation of observed trends. Both. exp.rimental and numerical results will be p.esented in th.s p.p.r for a selection of test configurations.

关键词： film h.le disch.rge coefficient turbulator blade cooling.

On th. role of th. constitutive model and basal texture on th. mech.nical beh.viour of magnesium alloy AZ31B sh.et

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Journal of Zh.jiang University-Science A(Ap.lied p.0}sics & Engineering) 2010年第10期11卷 744-755页

作者： h. WANG p. D. WU K. W. NEALE Dep.rtment of Mech.nical Engineering McMaster University Hamilton Ontario L8S 4L7 Canada Faculty of Engineering University of Sherbrooke Sherbrooke Quebec J1K 2R1 Canada

Th. recently develop.d elastic-viscop.astic self-consistent model with.various self-consistent sch.mes was ap.lied to study th. effect of basal texture on th. mech.nical beh.vior of magnesium alloy AZ31B sh.et. Th. influence of th. basal texture was investigated using various initial textures generated by artificially tilting th. measured texture of th. reference AZ31B sh.et around in a transverse direction. Th. material p.rameters for th. various models were fitted to exp.rimental uniaxial tension and comp.ession along th. rolling direction and were th.n used to study th. effects of th. basal texture on th. yield stress, R value, ultimate stress and uniform strain under uniaxial tension. Th. effect of th. basal texture on sh.et metal forming was furth.r assessed by calculating th. limit strain under in-p.ane p.ane strain tension. An assessment of th. p.edictive cap.bility of p.lycrystal p.asticity models was made based on comp.risons of p.edictions and exp.rimental observations. Among th. available self-consistent ap.roach.s, th. Affine self-consistent sch.me resulted in th. best overall p.rformance.

关键词： Magnesium alloys Crystal p.asticity Twinning Texture