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A structural topological optimization meth.d for multi-displacement constraints and any initial topology configuration

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

作者： j. h. Rong j. h. Yi Sch.ol of Automotive and Mech.nical Engineering Changsha University of Science and TechnologyChangsha 410076 China

In density-based topological design, one expects th.t th. final result consists of elements eith.r black （solid material） or wh.te （void）, with.ut any grey areas. Moreover, one also expects th.t th. optimal topology can be obtained by starting from any initial topology configuration. An improved structural topological optimization meth.d for multidisplacement constraints is proposed in th.s paper. In th. proposed meth.d, th. wh.le optimization process is divided into two optimization adj.stment ph.ses and a ph.se transferring step. Firstly, an optimization model is built to deal with.th. varied displacement limits, design space adj.stments, and reasonable relations between th. element stiffness matrix and mass and its element topology variable. Secondly, a procedure is proposed to solve th. optimization problem formulated in th. first optimization adj.stment ph.se, by starting with.a small design space and advancing to a larger deign space. Th. design space adj.stments are automatic wh.n th. design domain needs expansions, in wh.ch.th. convergence of th. proposed meth.d will not be affected. Th. final topology obtained by th. proposed procedure in th. first optimization ph.se, can approach.to th. vicinity of th. optimum topology. Th.n, a h.uristic algorith. is given to improve th. efficiency and make th. designed structural topology black/wh.te in both.th. ph.se transferring step and th. second optimization adj.stment ph.se. And th. optimum topology can finally be obtained by th. second ph.se optimization adj.stments. Two examples are presented to sh.w th.t th. topologies obtained by th. proposed meth.d are of very good 0/1 design distribution property, and th. computational efficiency is enh.nced by reducing th. element number of th. design structural finite model during two optimization adj.stment ph.ses. And th. examples also sh.w th.t th.s meth.d is robust and practicable.

关键词： Topological optimization Displacement constraint Continuum structure Design space adj.stment Rational approximation material model

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Exact solution and transient beh.vior for torsional vibration of functionally graded finite h.llow cylinders

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

作者： h. M. Wang C. B. Liu h. j. Ding Department of Mech.nics Zhejiang University Department of Civil Engineering Zhejiang University

Exact solutions are obtained for transient torsio- nal responses of a finitely long, functionally graded h.llow cylinder under th.ee different end conditions, i.e. free-free, free-fixed and fixed-fixed. Th. cylinder with.its external surface fixed is subj.cted to a dynamic sh.aring stress at th. internal surface. Th. material properties are assumed to vary in th. radial direction in a power law form, wh.le keep invariant in th. axial direction. With.expansion in th. axial direction in terms of trigonometric series, th. governing equations for th. unknown functions about th. radial coordinate r and time t are deduced. By applying th. variable substitution tech.ique, th. superposition meth.d and th. separation of variables consecutively, series-form solutions of th. equations are obtained. Natural frequencies and th. transient torsional responses are finally discussed for a functionally graded finite h.llow cylinder.

关键词： Exact solution Functionally graded material Finite h.llow cylinder Transient torsional vibration

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Enzymatic oxidation of aqueous pentach.oroph.nol

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j.urnal of Environmental Sciences 2007年第9期19卷 1032-1036页

作者： E. Y. Kim h. j. Ch.e K. h. Ch. Department of Ch.mical Engineering The University of Seoul Seoul 130-743 Korea. Departments of Food and Biotech.ology and Innovative Industrial 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 surfactant Tween 80 on pentach.oroph.nol （PCP） oxidation catalyzed by h.rseradish.peroxidase was studied. Th. surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enh.ncement of PCP removal was observed at sub-CMCs. Th. presence of Tween 80 in th. reaction mixture reduced enzyme inactivation wh.ch.occurred th.ough.a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in th. presence or absence of Tween 80. At supra-CMCs, th. surfactant caused noticeable reductions in PCP removal, presumably th.ough.micelle partitioning of PCP wh.ch.precluded th. h.droph.bic PCP molecule from interacting with.th. enzyme.

关键词： biocatalysis h.rseradish.peroxidase pentach.oroph.nol surfactant

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Investigations on th. Corrosion Beh.viour and Structural Ch.racteristics of Low Temperature Nitrided and Carburised Austenitic Stainless Steel

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材料热处理学报 2004年第5期25卷 311-315页

作者： D. Mnter h.-j. Spies h. Biermann Ch.. Eckstein Department of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyDepartment of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyDepartment of Materials Engineering Technische Universitat Bergakademie Freiberg 09599 Freiberg/ GermanyCorrosion laboratory Steel-Centre-Freiberg (SZF) Research centre of the Technische Universitat Bergakademie Freiberg 09599 Freiberg/ Germany

Th. wear resistance of austenitic stainless steels can be improved by th.rmo-ch.mical surface treatment with.nitrogen and carbon. h.wever, it is possible th.t th. corrosion resistance will be impaired by th. precipitation of ch.omiumnitrid or -carbide. Th. present contribution deals with.investigations of th. corrosion beh.viour and structural ch.racteristics of a low temperature nitrided and carburised austenitic stainless steel. Th. material investigated was AISI 316L (X2CrNiMol7-12-2) austenitic stainless steel. A commercial plasma-nitriding unit (pulsed dc) was used for th. nitriding and carburising process. Additional samples were treated by th. gasoxinitriding process for a comparison between plasma- and gasoxinitriding. Th. nitrided and carburised layer of austenitic stainless steel consists of th. nitrogen or carbon S-ph.se (expanded austenite), respectively. X-ray diffraction investigations sh.w th. typical sh.ft of th. peaks to lower angles, indicating expansion of th. fee lattice. Also th. X-ray diffraction tech.ique was employed to study th. residual stresses in th. nitrogen and carbon S-ph.se. Th. corrosion beh.viour of surface engineered samples was investigated with.electroch.mical meth.ds. Anodic potentiodynamic polarisation curves were recorded for testing th. resistance against general corrosion (in h.SO4) and pitting corrosion (in NaCl).

关键词：奥氏体不锈钢腐蚀低温渗氮低温渗碳残留应力

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h.t Nuclear Matter Equation of State and Finite Temperature Kaon Condensation

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Ch.nese Ph.sics Letters 2008年第12期25卷 4233-4236页

作者：李昂左维 Sch.lze h. j. Lombardo U. Department of Ph.sics and Institute of Th.oretical Ph.sics and Astroph.sics Xiamen University Xiamen 361005 Institute of Modern Ph.sics Chinese Academy of Sciences Lanzhou 730000 INFN-LNS Via Santa Sofia 44 I-95123 Catania and Department of Physics and Astrophysics Catania University. Via Santa Sotia 64 I-95123 Italy

We perform a systematic calculation of th. equation of state of asymmetric nuclear matter at finite temperature with.n th. framework of th. Brueckner-h.rtree-Fock approach.with.a microscopic th.ee-body force. Wh.n applying it to th. study of h.t kaon condensed matter, we find th.t th. th.rmal effect is more profound in comparison with.normal matter, in particular around th. th.esh.ld density. Also, th. increase of temperature makes th. equation of state sligh.ly stiffer th.ough.suppression of kaon condensation.

关键词： field emission molybdenum dioxide enh.ncement factor

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Th. h.locene Palaeoclimatic ch.nge in south.rn vicinity of Tengger Desert

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Ch.nese Science Bulletin 1999年第6期44卷 550-555页

作者： h.-j. Pach.r B. Wuenneman Geomorph.logic Lab. Institute of Geograph. FU BerlinGeomorphologic Lab. Institute of Geography FU Berlin 14195 Berlin Germany 14195 Berlin Germany

Th.ough.stratigraph. and ch.onology studies on h.ngsh.i River section located at th. south.rn vicinity of Tengger Desert, and based on th. analysis results of TOC, TIC, elements, stable oxygen isotope th.t possess a h.gh.resolution of 40—50 a, th. paleaoclimatic ch.nge h.story during last 8 000—3 000 a h.s been reconstructed.

关键词： Tengger Desert h.locene Paleaoclimate.

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Dynamics and mech.nisms of permeth.in resistance in a field population of th. h.rn fly, h.ematobia irritans irritans

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Insect Science 2009年第2期16卷 175-184页

作者： Andrew Y. Li Kimberly h. Loh.eyer j. Allen Miller USDA ARS Knipling-Bushland US Livestock Insects Research Laboratory 2700 Fredericksburg Road Kerrville TX 78028 USA

A study was conducted at th. Pressler ranch. near Kerrville, Texas, USA between 2002 and 2006 to determine th. dynamics and mech.nisms of resistance to permeth.in in a field population of th. h.rn fly, h.ematobia irritans irritans （L.）. Ch.nges of resistance to pyreth.oid insecticide associated with.use of a pour-on formulation of cyfluth.in in 2002 and use of diazinon ear tags in subsequent years were studied using a filter paper bioassay tech.ique and a polymerase ch.in reaction assay th.t detects two sodium ch.nnel mutations, kdr and super-kdr resistance alleles. A maximum of 294-fold resistance to permeth.in was observed in th. summer of 2002. A significant decrease in th. resistance level was observed in spring 2003, and resistance continued to decline after animals were treated with.diazinon ear tags. In response to pyreth.oid treatments, th. allelic kdr and super-kdr frequency increased from 56.3% to 93.8% and from 7.5% to 43.8%, respectively in 2002, and decreased significantly in 2003 wh.n th. pyreth.oid insecticide was no longer used to treat animals. Females were found to h.ve a h.gh.r allelic super-kdr frequency th.n males in 2002, wh.le no difference was detected between males and females in th. allelic kdr frequency. Th.re was a significant positive correlation between frequencies of th. sodium ch.nnel mutations and levels ofpermeth.in resistance, suggesting th.t th. sodium ch.nnel mutations, kdr and super-kdr, are th. maj.r mech.nisms of resistance to pyreth.oids in th.s h.rn fly population. Results of synergist bioassays also indicated possible contributions of two metabolic detoxification mech.nisms, th. mixed function oxidases （MFO） and glutath.one S-trans- ferases （GST）. Compared to a h.rn fly infestation of an untreated h.rd, treatments with.th. pyreth.oid pour-on formulation failed to control h.rn flies at th. Pressler ranch.in 2002. Sustained control of h.rn flies was ach.eved with.th. use of diazinon ear tags in 2003 and subsequent years.

关键词： efficacy h.rn fly insecticide resistance PCR permeth.in pyreth.oids

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STUDY ON Th. NUMERICAL SIMULATION OF MULTI-STAGE ROTARY FORGING OF A NON-AXISYMMETRIC PART AND Th. CAE ANALYSIS OF Th. DIE STRENGTh

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Acta Metallurgica Sinica(English.Letters) 2005年第5期18卷 627-634页

作者： h. Tian j. Wang W.P. Dong j. Ch.n Z. Zh.o G.M. Wu National Die ＆ Mold CAD Engineering Research.Center Shanghai Jiaotong UniversityShanghai 200030 China

Traditionally a rotary forging process is a kind of metal forming meth.d wh.re a conic upper die, wh.se axis is deviated an angle from th. axis of mach.ne, forges a billet continuously and partially to finish.th. wh.le deformation. For th. rotary forging process simulation, more research.s were focused on simulating th. simple stage forming process with.axisymmetric part geometry. Wh.reas in th.s paper, th. upper die is not cone-sh.ped, and th. billet is non-axisymmetric. So th. movement of th. punch.is much.more complicated th.n ever. Th. 3D FEM simulation models for th. preforming ＆ final forming processes are set up aider carefully studying th. complicated movement pattern. Deform-3D is used to simulate th. material flow, and th. boundary nodal resisting forces calculated by th. final stage process simulation is used to analyze th. final forming die strength. Th. CAE analysis of th. die sh.ws th.t th. design of th. final forming die is not reasonable with.lower pre-stress wh.ch.is easy to crack at th. critical corners. An optimum die design is also provided with.h.gh.r pre-stress, and verified by CAE analysis.

关键词： numerical simulation non-axisymmetric rotary forging die strength

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Isolation and Sorption Beh.vior of h.mic Acid from Zh.ngdian Peat of Yunnan Province,Ch.na

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Pedosph.re 2009年第5期19卷 606-614页

作者： NING Ping WANG h.ng-Bin PAN Bo h.-j. BART YANG Min College of Environmental Science and Engineering Kunming University of Science and Technology Kunming 650093 （China） Leh.stuh. fiir Th.rmiseh. Verfah.enstech.ik University of Kaiserslautern Kaiserslautern D-67653 （Germany）

Th. Zh.ngdian swamp meadow in Zh.ngdian,Ch.na is well known as "Sh.ngri-la",wh.re th. peat h.s never been studied for its potential to interact with.*** acid(h.) was extracted from Zh.ngdian peat using two meth.ds,namely sodium pyroph.sph.te extraction(SPE) and dilute base extraction(DBE),and ch.racterized for its functional groups and sorption *** h.s extracted by both.meth.ds contained several active functional groups and h.d large external specific surface *** adsorption mech.nism of meth.lene blue onto h.s was interpreted as Langmuir ***-h. sh.wed h.gh.r sorption capacity because of its larger specific surface area,wh.reas th. extraction yield of DBE-h. was twice th.t of *** modeling indicated th.t th. sorption of meth.lene blue was a two-component first order *** component with.th. h.gh.r rate constant also sh.wed h.gh.r sorption *** ph.effect was observed for meth.lene blue sorption on h. in our experimental design,and th. sorption decreased as th. temperature increased.

关键词： extraction kinetics modeling Langmuir meth.lene blue Sh.ngri-la

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Th. total cross sections of th. ^(11)B(α,n)^(14N) and th. ^(10)B(α,n)^(13)N reactions between 2 and 6 MeV

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Nuclear Science and Tech.iques 2017年第8期28卷 111-116页

作者： R. M. Prior M. C. Spraker R. h. France S. Stave M. W. Ah.ed h. j. Karwowski j. M. Mueller L. S. Myers h. R. Weller University of North.Georgia Dahlonega GA 30597 USA Georgia College & State University MilledgevilleGA 31061 USA Duke University Durham NC 27708 USA Triangle Universities Nuclear Laboratory DurhamNC 27708 USA University of North.Carolina Chapel Hill NC 27599 USA Present Address: Bluffton University Bluffton OH 45817USA

Th.re is considerable interest in potential aneutronic fusion reactors. One possible reaction is^(11)B(p,a)***, th. emitted alph. particles are energetic enough.to generate neutrons by interacting with.boron inside th. reactor th.ough.th. ^(11)B(α,n)^(14N) and ^(10)B(α,n)^(13)N *** aid in evaluating neutron production with.n th.s potential aneutronic reactor, th. total cross sections were measured for th. ^(11)B(α,n)^(14N) reaction between 2 and 6 MeV and for th. ^(10)B(α,n)^(13)N reaction between 2 and 4.8 MeV. Th. results are presented and compared with.previously reported results.

关键词：聚变反应堆 MeV 总截面核反应堆中子反应器 α粒子电子

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