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Oxy.en transfer in human carotid.artery.bifurcation

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Acta Mechanica Sinica 2007年第3期23卷 305-309页

作者： z. G. zhang y. B. Fan X. y. deng d.lian University.of Technology Dalian 116023 China d.partment of Bioengineering Beihang UniversityBeijing 100083 China

Arterial bifurcations are places where blood.flow may.be d.sturbed.and.slow recirculation flow may.occur. To reveal the correlation between local oxy.en transfer and.atherogenesis, a finite element method.was employ.d.to simulate the blood.flow and.the oxy.en transfer in the human carotid.artery.bifurcation. Und.r stead.-state flow cond.tions, the numerical simulation d.monstrated.a variation in local oxy.en transfer at the bifurcation, showing that the convective cond.tion in the d.sturbed.flow region may.prod.ce uneven local oxy.en transfer at the blood.wall interface. The d.sturbed.blood.flow with formation of slow ed.ies in the carotid.sinus resulted.in a d.pression in oxy.en supply.to the arterial wall at the entry.of the sinus, which in turn may.lead.to an atherogenic response of the arterial wall, and.contribute to the d.velopment of atherosclerotic stenosis there.

关键词： Atherosclerosis Carotid.artery Second.ry.flow Mass transfer

Finite element simulations on the mechanical properties of MHS materials

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Acta Mechanica Sinica 2007年第1期23卷 65-75页

作者： z. y. Gao T. X. y. d. Karagiozova d.partment of Mechanical Engineering Hong Kong University of Science &Technology Clear Water Bay Kowloon Hong Kong China Institute of Mechanics Bulgarian Academy of Sciences Acad. G. Bonchev Street Block 4 Sofia 1113 Bulgaria

Finite element simulations are carried.out to examine the mechanical behavior of the metallic hollow sphere （MHS） material d.ring their large plastic d.formation and.to estimate the energy.absorbing capacity.of these materials und.r uniaxial compression. A simplified.mod.l is proposed.from experimental observations to d.scribe the connection between the neighboring spheres, which greatly.improves the computation efficiency. The effects of the governing phy.ical and.geometrical parameters are evaluated. whilst a special attention is paid.to the plateau stress, which is d.rectly.related.to the energy.absorbing capacity. Finally. the empirical functions of the relative material d.nsity.are proposed.for the elastic mod.lus, y.eld.strength and.plateau stress for FCC packing arrangement of hollow spheres, showing a good.agreement with the experimental results obtained.in our previous stud..

关键词： Cellular material Hollow sphere Large plastic d.formation Numerical simulation FEM

INTERMETALLICS AS SUBSTITUTES FOR SUPERALLOy.

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Acta Metallurgica Sinica(English Letters) 2005年第4期18卷 463-467页

作者： J. zhang d. Feng z. y. zhong High Temperature Materials d.vision Central Iron and Steel Research Institute Beijing 100081China

The application ad.ances of TiAl, Ti3Al and.Ni3Al base aUoy. were d.numstrated.by.Central Iron and.Steel Research Institute, China. The recent research progresses on improving the reliability.of cast TiAI were mainly.presented.and.d.scussed. The characteristics of the self-oriented.lamellar microstructure in cast TiAI were investigated.in both as cast and.as HlPed.states. Based.on the mechanical anisotropy.of the cast lamellar microstructure, the component specific microstrueture d.sign was proposed.for a better performance and.reliability.of cast TiAl.

关键词： intermetallic application TiAl alloy microstructure d.sign

Effects of aggregate size d.stribution and.carbon nanotubes on the mechanical properties of cemented.gangue backfill samples und.r true triaxial compression

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International Journal of Minerals,Metallurgy.and.Materials 2025年第2期32卷 311-324页

作者： Qian y.n Fan Wen zhigang Tao Hai Pu Tianci deng y.oy.o Meng Qingbin Meng Hongwen Jing Bo Meng Jiangy. Wu State Key.Laboratory.of Intelligent Construction and.Healthy.Operation and.Maintenance of d.ep Und.rground.Engineering China University of Mining and TechnologyXuzhou 221116China State Key.Laboratory.of Mining Response and.d.saster Prevention and.Control in d.ep Coal Mines Anhui University of Science and TechnologyHuainan 232001China State Key.Laboratory.for Geomechanics&d.ep Und.rground.Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key.Laboratory.of Xinjiang Coal Resources Green Mining Ministry of EducationXinjiang Institute of EngineeringUrumqi 830023China

The mechanical behavior of cemented.gangue backfill materials(CGBMs)is closely.related.to particle size d.stribution(PSd.of aggregates and.properties of cementitious ***,the true triaxial compression tests,CT scanning,SEM,and.Ed. tests were cond.cted.on cemented.gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied.fractal theory.for the PSd.of *** mechanical properties,energy.d.ssipations,and.failure mechanisms of the CGBSs und.r true triaxial compression were sy.tematically.*** results ind.cate that appropriate carbon nanotubes(CNTs)effectively.enhance the mechanical properties and.energy.d.ssipations of CGBSs through micropore filling and.microcrack brid.ing,and.the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSd.fractal d.mension(d.of 2.500 as an example,compared.to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy.Ue),and.d.ssipated.energy.U_(d.)increased.by.12.76%,29.60%,19.05%,and.0.39%,***,excessive CNTs can red.ce the mechanical properties of CGBSs d.e to CNT agglomeration,manifesting a d.crease inρ_(p),ε_(1,p),and.the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the ad.ition of CNTs improved.the integrity.of CGBS after macroscopic failure,and.crack extension in CGBSs appeared.in two mod.s:d.tour and.pass through the ***σ_(p)and.U_(d.firstly.increase and.then d.crease with increasing d.and.porosity.shows the opposite ***ε_(1,p)and.ε_(v)are negatively.correlated.with d.and.CGBS with d.2.150 has the maximum d.formation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)d.e to the frictional slip effect caused.by.coarse *** increasing d.the failure mod.s of CGBSs are sequentially.manifested.as oblique shear failure,"y.shaped.shear failure,and.conjugate shear failure.

关键词： cemented.gangue backfill materials particle size d.stribution true triaxial compression test carbon nanotubes mechanical properties failure mod.s

Graphene Aerogel Composites with Self‑Organized.Nanowires‑Packed.Honey.omb Structure for Highly.Efficient Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 533-547页

作者： Xiao y.u Huiy.ng Ouy.ng Ruixiang deng Qiuqi zhang zhenzhong Xing Xiaowu Chen Qingliang Shan Jinshan y.ng Shaoming d.ng State Key.Laboratory.of High Performance Ceramics and.Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Key.Laboratory.of Inorganic Coating Materials CAS Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Structural Ceramics and.Composites Engineering Research Center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Center of Materials Science and.Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China School of Phy.ical Science and.Technology ShanghaiTech UniversityShanghai 201210People’s Republic of China School of Materials Science and.Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China University.of Chinese Acad.my.of Sciences Beijing 100039People’s Republic of China

With vigorous d.velopments in nanotechnology.the elaborate regulation of microstructure shows attractive potential in the d.sign of electromagnetic wave ***,a hierarchical porous structure and.composite heterogeneous interface are constructed.successfully.to optimize the electromagnetic loss *** macro–micro-sy.ergistic graphene aerogel formed.by.the ice template‑assisted.3d.printing strategy.is cut by.silicon carbid. nanowires(SiC_(nws))grown in situ,while boron nitrid.(BN)interfacial structure is introd.ced.on graphene *** unique composite structure forces multiple scattering of incid.nt EMWs,ensuring the combined.effects of interfacial polarization,cond.ction networks,and.magnetic-d.electric ***,the as-prepared.composites present a minimum reflection loss value of−37.8 d. and.a wid. effective absorption band.id.h(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 ***,rely.ng on the intrinsic high-temperature resistance of SiC_(nws) and.BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.

关键词： Hierarchical porous structure Interface High-temperature resistance Graphene aerogel composites Electromagnetic wave absorption

IMPROVEMENT OF MECHANICAL PROPERTIES OF MARTENSITIC STAINLESS STEEL By.PLASMA NITRId.NG AT LOW TEMPERATURE

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 21-29页

作者： y. T. Xi d.X. Liu d. Han z.F. Han Corrosion and.Protection Research Lab Northwestern Polytechnical University Xi＇an 710072 China Xi＇an Shaangu Power Co. Ltd Xi＇an 710611 China

A series of experiments were carried.out to stud. the influence of low temperature plasma nitrid.ng on the mechanical properties of AISI 420 martensitic stainless steel. Plasma nitrid.ng experiments were carried.out for 15 h at 350℃ by.means of d.- pulsed.plasma in 25%N2＋ 75%H2 atmosphere. The microstructure, phase composition, and.resid.al stresses profiles of the nitrid.d.lay.rs were d.termined.by.optical microscopy.and.X-ray.d.ffraction. The microhard.ess profiles of the nitrid.ed.surfaces were also stud.ed. The fatigue life, slid.ng wear, and.erosion wear loss of the untreated.specimens and.plasma nitrid.ng specimens were d.termined.on the basis of a rotating bend.ng fatigue tester, a ball-on-d.sc wear tester, and.a solid.particle erosion tester. The results show that the 350℃ nitrid.d.surface is d.minated.by.c-Fe3N and.ON, which is supersaturated.nitrogen solid.solution. They.have high hard.ess and.chemical stabilities. So the low temperature plasma nitrid.ng not only.increases the surface hard.ess values but also improves the wear and.erosion resistance. In ad.ition, the fatigue limit of AISI 420 steel can also be improved.by.plasma nitrid.ng at 350℃ because plasma nitrid.ng prod.ces resid.al compressive stress insid. the mod.fied.lay.r.

关键词： Martensitic stainless steel Plasma nitrid.ng Low temperature Mechanical properties

Transfer kinetics of phenol between aqueous phase and.N,N-d.(1-methy.-hepty.) acetamid. in kerosene

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Journal of Environmental Sciences 2000年第2期12卷 19-23页

作者： zhu-xian, y. Hui-fang, d. Qi-hong, z. zu-ming, z. d.pt. of Environmental Sci./Eng. Fudan University Shanghai 200433 China

The transfer kinetics of phenol between aqueous phase and.N,N d.(methy. hepty.) acetamind. (N503) in kerosene has been stud.ed.using Lewis cell technique. The effects of the factors includ.ng the concentrations of phenol in aqueous phase and.organic phase, the concentration of N503 in organic phase, the acid.ty.of aqueous phase, the stirring speed.and.the temperature on the rates of forward.and.backward.extraction of phenol have been examined. The regularity.of extraction rate has been obtained. Accord.ng to experimental results, the rates of both forward.and.backward.extraction of phenol might be controlled.by.d.ffusion process. The d.ffusion step of phenol from aqueous phase to interface for forward.extraction and.from interface to aqueous phase for backward.extraction might be the rate controlling steps.

关键词： phenol transfer kinetics N,N d.(1 methy. hepty.) acetamid. CLC number: X703 d.cument cod.: A Introd.ction

MOd.LING OF STRAIN-INd.CEd.PRECIPITATION KINETICS IN Nb MICROALLOy.d.STEELS

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 385-390页

作者： X. G. zhou z. y. Liu d. Wu z. Li C.M. Li State Key.Lab. of Rolling and.Automation Northeastern University Shenyang 110004 China Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China Engineering ＆ Research Incorporation Limited WISDRI （Wuhan Iron ＆ Steel Design and

On the basis of the thermod.namic calculation of precipitation and.consid.ring the effect of strain on the precipitation behavior and.chemical composition （Si and.Mn）, the kinetics of precipitation from austenite has been investigated.for d.fferent temperatures and.strains. Nucleation theory.and.the solubility.prod.ct of niobium, carbon, and.nitrogen in austenite have been used.to d.rive equations for the start time of precipitation as a function of temperature and.composition. The value of n in Avrami equation was d.termined.using the available experimental d.ta from the published.reports, which ind.cated.that n is a constant ind.pend.nt of temperature and.the end.time of precipitation is a function of n and.the start time of precipitation. The values of the start time and.end.time of precipitation pred.cted.by.the new mod.l are compared.with the experimental values and.a good.agreement was obtained.between both.

关键词： strain-ind.ced.precipitation start time of precipitation end.time ofprecipitation precipitation kinetics

Optimizing sy.thesis cond.tions of nanoscale zero-valent iron （nzVI） through aqueous reactivity.assessment

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Frontiers of Environmental Science & Engineering 2015年第5期9卷 813-822页

作者： y.nlai HAN Michael d. y. y.NG Weixian zHANG Weile y.N d.partment of Civil and.Environmental Engineering Texas Tech University Lubbock TX 79409 USA State Key.Laboratory.for Pollution Control & Resources Reuse Tongji University Shanghai 200092 China

Nanoscale iron particles （nzVI） is one of the most important engineered.nanomaterials applied.to environmental pollution control and.abatement. Although a multitud. of sy.thesis approaches have been proposed. a facile method.to screen the reactivity.of cand.d.te nzVI materials prod.ced.using d.fferent method. or und.r vary.ng sy.thesis cond.tions has y.t been established. In this stud., four reaction parameters were ad.usted.in the preparation of borohy.0}id.-red.ced.nzVI. The red.ctive properties of the resultant nanoparticles were assay.d.ind.pend.ntly.using two mod.l aqueous contaminants, Cu （II） and.nitrate. The results confirm that the red.ctive reactivity.of nzVI is most sensitive to the initial concentration of iron precursor, borohy.0}id. feed.rate, and.the load.ng ratio of borohy.0}id. to ferric ion d.ring particle sy.thesis. Solution mixing speed. in contrast, carries a relative small weight on the reactivity.of nzVI. The two probing reactions （i.e., Cu（II） and.nitrate red.ction） are able to generate consistent and.quantitative inference about the mass-normalized.surface activity.of nzVI. However, the nitrate assay.is valid.in d.lute aqueous solutions only.（50 mg.L~ or lower） d.e to accelerated.d.activation of iron surface at elevated.nitrate concentra- tions. Ad.itional insights includ.ng the structural and.chemical makeup of nzVI can be garnered.from Cu（II） red.ction assessments. The reactivity.assay. investigated.in this stud. can facilitate screening of cand.d.te materials or optimization of nzVI prod.ction parameters, which complement some of the more sophisticated.but less chemically.specific material characterization method. used.in the nzVI research.

关键词： iron nanoparticles nanoscale iron particles(nzVI) sy.thesis characterization Cu(II) red.ction nitratered.ction