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Ef.ect of.Alloying Additions on the Oxidation of.High Speed Steels under Dry and Wet Conditions

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中国腐蚀与防护学报 2009年第4期29卷 241-247页

作者： f. C. RIZZO m. J. mONTEIRO S. R. J. SAUNDERS DCmm PUC Rio de Janeiro Brazil Bentley Surrey UK

An investigation has been carried out into the ef.ects of.chromium and vanadium content on the oxidation rate and on the adhesion of.oxide scales grown on three dif.erent chemical compositions of.high speed steels under dry and wet *** oxidation tests were carried out in a thermobalance at 650℃f.r up to 14.4 *** mass gain of.the specimens increased with increasing contents of.water vapour. Alloy composition had no ef.ect on the oxidation rate in dry ***'adhesion'of.the oxide scale was determined using indentation with a Rockwell C diamond and the pull adhesion test to determine the interf.cial toughness and the tensile strength of.the oxide metal bond,***,the results of.the investigation indicated that oxide adhesion was lowest f.r the specimens exposed to dry conditions, and that with increasing water vapour content,the scale was more *** test results showed that an increase in the V concentration was deleterious to oxide adhesion in both the dry and wet environments,whereas an increase in the Cr-content had little ef.ect on adhesion.

关键词：合金腐蚀氧化金属材料

Natural convective heat transf.r and nanof.uid f.ow in a cavity with top wavywall and corner heater

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Journal of.Hydrodynamics 2016年第5期28卷 873-885页

作者： mikhail A. SHEREmET Ioan POP Hakan f. OZTOP Nidal ABU-HAmDEH Department of.Theoretical mechanics Tomsk State University Tomsk Russia Department of.Nuclear and Thermal Power Plants Tomsk Polytechnic University Tomsk Russia Department of.Applied mathematics BabesBolyai University Cluj-Napoca Romania Department of.mechanical Engineering Technology Faculty Flrat University Elazig Turkey mechanical Engineering Department Faculty of Engineering King Abdulaziz University Jeddah Saudi Arabia

A numerical analysis of.natural convection of.nanof.uid in a wavy-walled enclosure with an isothermal comer heater has been carried out. The cavity is heated f.om the lef. bottom comer and cooled f.om the top wavy wall while the rest walls are adiaba- tic. mathematical model has been f.rmulated using the single-phase nanof.uid approach. main ef.orts have been f.cused on the ef.ects of.the dimensionless time, Rayleigh number, undulation number, nanoparticle volume f.action and length of.comer heaters on the f.uid f.ow and heat transf.r inside the cavity. Numerical results have been presented in the f.rm of.streamlines, isotherms, velocity and temperature prof.les, local and average Nusselt numbers. It has been f.und that nanoparticle volume f.action essentially af.ects both f.uid f.ow and heat transf.r while undulation number changes signif.cantly only the heat transf.r rate.

关键词： wavy cavity natural convection nanof.uid comer heater numerical results

The f.rmation and catalytic activity of.silver nanoparticles in aqueous polyacrylate solutions

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f.ontiers of.Chemical Science and Engineering 2016年第3期10卷 432-439页

作者： Jie Wang Jianjia Liu Xuhong Guo Liang Yan Stephen f. Lincoln State Key Laboratory of.Chemical Engineering East China University of Science and Technology Shanghai 200237 China Department of.Chemistry University of Adelaide Adelaide SA 5005 Australia

Silver nanoparticles （AgNPs） have been synthesized in the presence of.polyacrylate through the reduction of.silver nitrate by sodium borohydride in aqueous solution. The AgNO3 and polyacrylate carbox- ylate group concentrations were kept constant at 2.0× 10^-4 and 1.0 × 10^-2 mol·L^-1, respectively, while the ratio of.[NaBH4]/[AgNO3] was varied f.om 1 to 100. The ultra- violet-visible plasmon resonance spectra of.these solutions were f.und to vary with time prior to stabilizing af.er 27 d, consistent with changes of.AgNP size and distribution within the polyacrylate ensemble occurring. These obser- vations, together with transmission electron microscopic results, show this rearrangement to be greatest among the samples at the lower ratios of.[NaBH4]/[AgNO3] used in the preparation, whereas those at the higher ratios showed a more even distribution of.smaller AgNP. All ten of.the AgNP samples, upon a one thousand-f.ld dilution, catalyze the reduction of.4-nitrophenol to 4-aminophenol in the temperature range 283.2-303.2 K with a substantial induction time being observed at the lower temperatures.

关键词： silver nanoparticles polyacrylates catalysis,mechanism sodium borohydride

Interactive data styling and multif.cal visualization f.r a multigrid web-based Digital Earth

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International Journal of.Digital Earth 2021年第3期14卷 288-310页

作者： m.J.Sherlock m.Hasan f.f.Samavati Department of.Computer Science University of CalgaryCalgaryCanada

Globe-based Digital Earth(DE)is a promising system that uses 3D models of.the Earth f.r integration,organization,processing,and visualization of.vast multiscale geospatial *** growing size and scale of.geospatial datasets present signif.cant obstacles to interactive viewing and meaningf.l visualizations of.these DE *** address these challenges,we present a novel web-based multiresolution DE system using a hierarchical discretization of.the globe on both server and client *** presented web-based system makes use of.a novel data encoding technique f.r rendering large multiscale geospatial datasets,with the additional capability of.displaying multiple simultaneous *** the data needed f.r the current views and scales are encoded and *** leverage the power of.GPU acceleration on the client-side to perf.rm real-time data rendering and dynamic *** rendering of.multiple views allows us to support multilevel f.cus+context visualization,an ef.ective approach to navigate through large multiscale global *** client–server interaction as well as the data encoding,rendering,styling,and visualization techniques utilized by our presented system contribute toward making DE more accessible and inf.rmative.

关键词： Digital Earth Discrete Global Grid System data integration data f.sion multilevel f.cus+context visualization spatial resolution context awareness

Analysis of.Heat Transf.r Phenomenon in magnetohydrodynamic Casson f.uid f.ow Through Cattaneo–Christov Heat Dif.usion Theory

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Communications in Theoretical Physics 2017年第7期67卷 91-95页

作者： G. K. Ramesh J. Gireesha, S. A. Shehzad, f. m. Abbasi Department of.mathematics School of Engineering Presidency University Bengaluru-560089 Karnataka India Department of.Studies and Research in mathematics Kuvempu University Shankaraghatta-577451 Shimoga Karnataka India Department of.mathematics COMSATS Institute of Information Technology Sahiwal-57000 Pakistan Department of.mathematics COMSATS Institute of Information Technology Islamabad-44000 Pakistan

Heat transport phenomenon of.two-dimensional magnetohydrodynamie Casson f.uid f.ow by employing Cattaneo-Christov heat dif.usion theory is described in this work. The term of.heat absorption/generation is incorporated in the mathematical modeling of.present f.ow problem. The governing mathematical expressions are solved f.r velocity and temperature prof.les using RKf.45 method along with shooting technique. The importance of.arising nonlinear quantities namely velocity, temperature, skin-f.iction and temperature gradient are elaborated via plots. It is explored that the Casson parameter retarded the liquid velocity while it enhances the f.uid temperature. f.rther, we noted that temperature and thickness of.temperature boundary layer are weaker in case of.Cattaneo-Christov heat dif.usion model when matched with the prof.les obtained f.r f.urier＇s theory of.heat f.ux.

关键词： Hydromagnetic f.ow Casson f.uid heat transf.r Cattaneo-Christov heat dif.usion model numer-ical solution

ON THE CONVERGENCE Of.THE PARABOLIC APPROXImATION Of.A CONSERVATION LAW IN SEVERAL SPACE DImENSIONS

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Chinese Annals of.mathematics,Series B 1999年第1期20卷 7-10页

作者： T. GALLOUET f. HUBERT(Universite de Provence,C.m.I.,39 rue f.Joliot Curie,13453 marseille Cedex 13,f.ance) Univ Aix marseille 1 CMI F-13453 Marseille 13 France

The authors give a proof.of.the convergence of.the solution of.the parabolic approximation towards the entropic solution of.the scalar conservation law div f.x, t, u) = 0 in several space dimensions. f.r any initial condition uo (RN) and f.r alarge class of.f.ux f. they also prove the strong converge in any space, using the notion of.ntropy process solution, which is a generalization of.the measure-valued solutions of.Diperna.

关键词： Convergence Parabolic approximation Conservation law

modif.ed Burzynski criterion with non-associated f.ow rule f.r anisotropic asymmetric metals in plane stress problems

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Applied mathematics and mechanics(English Edition) 2015年第3期36卷 303-318页

作者： f.mOAYYEDIAN m.KADKHODAYAN Department of.mechanical Engineering Ferdowsi University of Mashhad

The Burzynski criterion is developed f.r anisotropic asymmetric metals with the non-associated f.ow rule （NAf.） f.r plane stress problems. The presented pressure depending on the yield criterion can be calibrated with ten experimental data, i.e., the tensile yield stresses at 0°, 45°, and 90°, the compressive yield stresses at 0°, 15°, 30°, 45°, 75°, and 90° f.om the rolling direction, and the biaxial tensile yield stress. The corresponding pressure independent plastic potential f.nction can be calibrated with six experimental data, i.e., the tensile R-values at 0°, 15°, 45°, 75°, and 90° f.om the rolling direction and the tensile biaxial R-value. The downhill simplex method is used to solve these ten and six high nonlinear equations f.r the yield and plastic potential f.nctions, respectively. The results show that the presented new criterion is appropriate f.r anisotropic asymmetric metals.

关键词： modif.ed Burzynski criterion pressure dependent asymmetric metal down-hill simplex method non-associated f.ow rule (NAf.)

Synthesis and Crystal Structure of.a New Potassium Yttrium Diphosphate Dihydrate KYP_2O_7·2H_2O

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Chinese Journal of.Structural Chemistry 2008年第10期27卷 1199-1204页

作者： f.rid m Horchani-Naif.r K Unité de Recherches de matériaux de Terres Rares Centre National de Recherches en Sciences des MatériauxB.P.95 Hammam-Lif 2050Tunisie

The dihydrated potassium yttrium diphosphate, KYP2O7·2H2O, has been synthesized f.r the f.rst time. Single-crystal XRD study has allowed the determination of.its structure and correct f.rmula. It crystallizes in the monoclinic system, space group P21/c, with the cell parameters a = 7.7069（3）, b = 10.5801（4）, c = 10.0204（5）A,β = 93.24（3）A, V= 815.76（6）A^3, Z= 4, mr = 337.98, f.000） = 656, Dc = 2.752 g/cm^3 and/t = 8.073 mm^-1. The single-crystal structure was solved f.om 1856 unique ref.ections with the f.nal R = 0.0365 and wR = 0.0772, ref.ned with 119 parameters. The atomic arrangement of.KYP2O7·2H2O is built by the P2O7 groups, the YO7 and the KO10 polyhedrons which are connected by corner and edge-sharing to f.rm a three-dimensional f.amework. Water molecules are directly bonded to the Y and K atoms, and they are located in channels running along the a direction.

关键词： crystal structure yttrium diphosphate inf.ared spectrum TGA-DTA analysis

Crouzon syndrome mouse model exhibits cartilage hyperprolif.ration and def.ctive segmentation in the developing trachea

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Science China(Lif. Sciences) 2019年第10期62卷 1375-1380页

作者： Elizabeth A. Hines mary-Kayt N. Jones Julie f. Harvey Chad Perlyn David m. Ornitz Xin Sun Jamie m. Verheyden Laboratory of.Genetics University of WisconsinMadisonWI 53706USA Department of.Surgery Florida International University College of MedicineMiamiFL 33199USA Department of.Developmental Biology Washington University School of MedicineSt. LouisMO 63110USA Department of.Pediatrics University of California-San DiegoLa JollaCA 92093USA

Crouzon syndrome is the result of.a gain-of.f.nction point mutation in f.f.2. mimicking the human mutation, a mouse model of.Crouzon syndrome(f.f.2342Y) recapitulates patient def.rmities, including f.iled tracheal cartilage segmentation, resulting in a cartilaginous sleeve in the homozygous mutants. We f.und that the f.f.2C342Y/C^342Y mutants exhibited an increase in chondrocytes prior to segmentation. This increase is due at least in part to over prolif.ration. Genetic ablation of.chondrocytes in the mutant led to restoration of.segmentation in the lateral but not central portion of.the trachea. These results suggest that in the f.f.2C342Y/C342Y mutants, increased cartilage cell prolif.ration precedes and contributes to the disruption of.cartilage segmentation in the developing trachea.

关键词： trachea lung mouse development