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Local Entropy Production in Turbulent Sh.ar f.ows:A Tool f.r Evaluating h.at Transf.r Perf.rmance

第十七届全国波谱学学术会议

作者： Mary Y. h. Donald M. Camaioni Romulus V. f. Turcu Aleksei Vjunov Zizwe Ch.se charles h. f. peden Joh.nnes A. Lerch.r Pacif.c North.est National Laboratory RichlandWA 99354USA

Magic angle spinning (MAS) at both.h.gh.temperatures (i.e.,greater th.n about 100 °C) and h.gh.pressures (i.e.,th. vapor pressure of.aqueous water at h.gh.temperature) h.s not yet been realized,alth.ugh.our recent pr...

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Journal of.Th.rmal Science 2006年第2期15卷 159-167页

作者： h. h.RWIG f. KOCK h.mburg University of.Tech.ology 21073 h.mburg Germany. BMW 80788 Munich Germany

Perf.rmance evaluation of.h.at transf.r devices can be based on th. overall entropy production in th.se devices. In our study we th.ref.re provide equations f.r th. systematic and detailed determination of.local entropy production due to dissipation of.mech.nical energy and due to h.at conduction, both.in turbulent f.ows. Af.er turbulence modeling h.s been incorporated f.r th. f.uctuating parts th. overall entropy production can be determined by integration with.respect to th. wh.le f.ow domain. Since, h.wever, entropy production rates sh.w very steep gradients close to th. wall, numerical solutions are f.r more ef.ective with.wall f.nctions f.r th. entropy production terms. Th.se wall f.nctions are mandatory wh.n h.gh.Reynolds number turbulence models are used. f.r turbulent f.ow in a pipe with.an inserted twisted tape as h.at transf.r promoter it is sh.wn th.t based on th. overall entropy production rate a clear statement f.om a th.rmodynamic point of.view is possible. f.r a certain range of.twist strength.th.re is a decrease in overall entropy production compared to th. case with.ut insert. Also, th. optimum twist strength.can be determined. Th.s inf.rmation is unavailable wh.n only pressure drop and h.at transf.r data are given.

关键词： entropy production turbulent h.at transf.r wall f.nctions

Simulation of.th. f.ssion dynamics of.th. excited compound nuclei ^206Po and ^168Yb produced in th. reactions ^12C＋^194Pt and ^18O＋^150Sm

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Ch.nese Ph.sics C 2017年第4期41卷 69-74页

作者： h. Eslamizadeh.f. Bagh.ri Department of.Ph.sics Persian Gulf University *** Bushehr Iran

A two-dimensional dynamical model based on th. Langevin equation was used to study th. f.ssion dynamics of.th. compound nuclei ^206Po and ^168Yb produced in th. reactions ^12C＋^194Pt and ^18O＋^150Sm,*** f.ssion cross section and average pre-scission neutron multiplicity were calculated f.r th. compound nuclei ^206Po and ^168Yb,and results of.th. calculations compared with.th. experimental *** elongation coordinate was used as th. f.rst dimension and th. projection of.th. total spin of.th. compound nucleus onto th. symmetry axis,K,considered as th. second dimension in th. Langevin dynamical *** th. two-dimensional calculations,a constant dissipation coef.icient of.K and a non-constant dissipation coef.icient h.ve been used to reproduce th. abovementioned experimental *** is sh.wn th.t th. two-dimensional Langevin equation can satisf.ctorily reproduce th. f.ssion cross section and average pre-scission neutron multiplicity f.r th. compound nuclei ^206Po and ^168Yb by using constant values of.th. dissipation coef.icient of.K equal to γκ=0.18（MeV zs）^-1/2 and γκ= 0.20（MeV zs）^-1/2f.r th. compound nuclei ^206Po and ^168Yb,respectively.

关键词： dissipation coef.icient Langevin model f.ssion cross section

Can h.avier Liquid f.oat on Top of.a Ligh.er One？

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Ch.nese Ph.sics Letters 2011年第1期28卷 127-129页

作者： A. h. Ayyad f. Takrori Department of.Ch.mistry Faculty of Science and Technology Hebron University P.O. Box 40 Hebron West Bank Palestine

We report on a f.rst observation of.a f.oating- sph.rical h. （density 13g/cm3） drop on top of.a glycerin （density 1.26g/cm3） drop, th. latter is h.misph.rical and about f.ur times larger in volume. Th.s observation is clearly against nature＇s gravity law and h.s never been reported bef.re. h.re we present spectacular h.gh.resolution ph.tos th.t clearly demonstrate th.s remarkable f.oating ph.nomenon. Using milli-Q water, th. h. drop would stay down adh.red at th. triple line. Instead, th. coincidental use of.tap water displays th. same ph.nomenon. Increasing th. volume of.th. supporting liquid to a certain value causes th. h. drop to sink. A 5-M NaCl aqueous solution is f.und enough.to sh.w th. same f.oating ph.nomenon. Th.s f.oating mercury as a ph.nomenon is puzzling. On th.s length.scale it seems th.t surf.ce tension and curvature dominate over gravity.

关键词： Sof. matter liquids and polymers f.uid dynamics Surf.ces interf.ces and th.n f.lms

AITEB - An European Research.Project 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.f.ER Rolls-Royce Deutsch.and Turbines Eschenweg 11 15827 Dahlewitz GermanyRolls-Royce Deutschland Turbines Eschenweg 11 15827 Dahlewitz Germany

Th. paper delivers an overview on th. European research.project AITEB - Aeroth.rmal Investigations on Turbine Endwalls and Blades, wh.ch.started in year 2000 in th. course of.th. 5. f.amework Programme (GROWTh.. Th. aim is to submit an integrated tech.ology and design tool package f.r th. advanced, aeroth.rmal h.gh.y loaded design of.turbines, especially: Experimental/numerical investigation on h.at transf.r and f.lm-cooling in separated f.ow f.r h.gh.y loaded blades including advanced trailing edge cooling h.at transf.r/ improved cooling of.turbine endwalls: Experimental/numerical work on cooling of.turbine endwalls, sh.ouds and recessed blade tips. Optimised Cf.-process (drawing-grid-modelling-postprocessing-risk assessment) in order to derive th. 'best practice' to use Cf. as a time ef.ective tool. Af.er most of.th. project lif., an overview on th. project is delivered. Experimental results of.test series at various test sites are compared to numerical simulations of.th. industrial and university partners.

关键词： turbines aeroth.rmal endwalls blades cooling-tech.ology experiment Cf..

ON MULTIPLICATION AND COMULTIPLICATION MODULES

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Acta Math.matica Scientia 2011年第2期31卷 694-700页

作者： h. Ansari-Torogh. f. f.rsh.dif.r Department of.Math.matics Faculty of Science University of Guilan

Th.s article deals with.some results concerning multiplication and comultipli- cation modules over a commutative ring.

关键词： Multiplication modules comultiplication modules cocyclic modules

Th. Zariski Topology on th. Second Spectrum of.a Module

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Algebra Colloquium 2014年第4期21卷 671-688页

作者： h. Ansari-Torogh. f. f.rsh.dif.r Department of.Pure Math.matics Faculty of Mathematical Sciences University of Guilan P.O. Box 41335-19141 Rasht Iran

Let R be a commutative ring and M be an R-module. Th. second spectrum Spec^S（M） of.M is th. collection of.all second submodules of.M. We topologize Spec^S（M） with.Zariski topology, wh.ch.is analogous to th.t f.r Spec（R）, and investigate th.s topolog- ical space. f.r various types of.modules M, we obtain conditions under wh.ch.Spec^S（M） is a spectral space. We also investigate Specs （M） with.quasi-Zariski topology.

关键词： second submodule second spectrum cotop module spectral space Zariskitopology

Mech.no-th.rmal synth.sis and ch.racterization of.nano-structured f./f.S f.r application in ph.tocatalysis

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Particuology 2018年第2期16卷 72-80页

作者： h. Esmaili S. Sh.ibani f. Rash.h. Sch.ol of.Metallurgy and Materials Engineering College of Engineering University of Tehran Tehran 11155-4563 Iran

A novel meth.d was used to prepare a nano-structured 32 wt% f./f.S core/sh.ll powder via a mech.noth.rmal route by l-h.h.at treatment of.a mech.nically activated powder mixture of.f. and S. Th. structural and microstructural ch.racteristics, f.rmation mech.nism, magnetic properties, and ph.tocatalytic activity of.th. powder were studied by X-ray dif.raction, f.eld emission scanning electron microscopy, transmission electron microscopy, surf.ce area analysis, dif.erential scanning calorimetry, vibrating sample magnetometry, and UV-vis spectroph.tometry. A detailed study of.th. mech.nism of.transf.rmation sh.wed th.t during th. h.at treatment process, an f.S2 ph.se was f.rmed as th. intermediate product. In th. f.nal product, an f.S sh.ll approximately 2 nm in th.ckness was f.rmed on th. f. core. In th. presence of.NaCI as a process control agent, th. particle size decreased and th. size distribution became more unif.rm. Mech.nical activation and NaCI addition togeth.r led to a decrease of.th. saturation magnetization f.om 82 to 74emu/g. Th. ph.tocatalytic activity of.th. powder in th. degradation of.meth.lene blue was 50%.

关键词： f./f.S Core-sh.ll Mech.no-th.rma Nano-structure Ph.tocatalyst

Ab-Initio Study of.Cobalt Impurity Ef.ects on Ph.non Spectra, Mech.nical and Th.rmal Properties of.Single Wall Carbon Nanotube （5,0）

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Ch.nese Ph.sics Letters 2014年第4期31卷 110-113页

作者： h. Tash.kori B. Kh.sh.evisan f. Kanjouri f.culty of.Ph.sics University of Kashan Kashan Iran f.culty of.Ph.sics Kharazmi University Karaj Iran

We use density f.nctional perturbation th.ory based on th. pseudo-potential to calculate th. ph.non spectrum, ph.non density of.states, specif.c h.at capacity and mech.nical properties of.pristine and cobalt doped （5,0） single wall carbon nanotube （CNT）. In th. calculations, we consider one Co atom in th. center of.th. unit cell of.th. tube and it is sh.wn th.t th. pristine （5~0） CNT is nonmagnetic wh.le th. Co-doped tube becomes magnetic. Young＇s modulus f.r both.systems is about 1 TPa （＇af.er Co-doping it goes sligh.ly h.gh.r） and th. Poisson ratio f.r th. pristine tube becomes quite a bit larger th.n th. doped one. On th. oth.r h.nd, th. calculated value of.radial breath.mode f.r th. pristine CNT is in good agreement with.th. experimental reports wh.le af.er Co-doping it is increased. In addition, h.at capacity of.th. doped CNT is reduced, wh.ch.leads to some important empirical applications.

关键词： Wall Carbon Nanotube Ab-Initio pseudo-potential