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Microstructure and mechanical behavior of laser aided additive manufactured low carbon interstitial Fe_(49.5)Mn_(30)co_(10)Cr_(10)C_(0.5)multicomponent alloy

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Journal of Materials Science & Technology 2021年第18期77卷 38-46页

作者： y.Chew Z.G.Zhu F.Weng S.B.Gao F.L.Ng B.y Lee G.J.Bi Singapore Institute of Manufacturing Technology 73 Nanyang Drive637662Singapore School of Mechanical Aerospace Engineering Nanyang Technological University50 N any ang Avenue639798Singapore

Laser aided additive manufacturing(LAAM)was used to fabricate bulk Fe_(49.5)Mn_(30)co_(10)Cr_(10)C_(0.5)interstitial multicomponent alloy using pre-alloyed *** room temperature yield strength(σ_y),ultimate tensile strength(σ_(UTS))and elongation(ε_(UTS))were 645 MPa,917 MPa and 27.0%*** asbuilt sample consisted of equiaxed and dendritic cellular structures formed by elemental *** cellular structures together with oxide particle inclusions were deemed to strengthen the *** other contributing components include dislocation strengthening,friction stress and grain boundary *** highε_(UTS)was attributed to dislocation motion and activation of both twinning and transformation-induced plasticity(TWIP and TRIP).Tensile tests performed at-40℃and-130℃demonstrated superior tensile strength of 1041 MPa and 1267 MPa ***,almost no twinning was observed in the fractured sample tested at-40℃and-130℃.Instead,higher fraction of strain-induced hexagonal close-packed(HCP)εphase transformation of 21.2%were observed for fractured sample tested at-40℃,compared with 6.3%in fractured room temperature sample.

关键词： Multicomponent alloys Laser aided additive manufacturing Additive manufacturing Microstructure Mechanical property

Schottky photodiode using submicron thick diamond epilayer for flame sensing

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Nano-Micro Letters 2009年第1期1卷 30-33页

作者： y.Koide M.y.Liao J.Alvarez M.Imura K.Sueishi F.yoshifusa Sensor Materials Center (SenMC) National Institute for Materials Science (NIMS) Laboratoire de Génie Electrique de Paris (UMR 8507 CNRS) Ecole Supérieure d’Electricité Universités Paris VI et Paris XI International Center for Materials Nanoarchitectonics (MANA) National Institute for Materials Science (NIMS) ANTEC co.

The sensing of a flame can be performed by using wide-bandgap semiconductors, which offer a high signal-to-noise ratio since they only response the ultraviolet emission in the flame. Diamond is a robust semiconductor with a wide-bandgap of 5.5 e V, exhibiting an intrinsic solar-blindness for deep-ultraviolet(DUV) detection. In this work, by using a submicron thick boron-doped diamond epilayer grown on a type-Ib diamond substrate, a Schottky photodiode device structure- based flame sensor is demonstrated. The photodiode exhibits extremely low dark current in both forward and reverse modes due to the holes depletion in the epilayer. The photodiode has a photoconductivity gain larger than 100 and a threshold wavelength of 330 nm in the forward bias mode. co and OH emission bands with wavelengths shorter than 330 nm in a flame light are detected at a forward voltage of-10 V. An alcohol lamp flame in the distance of 250 mm is directly detected without a focusing lens of flame light.

关键词： Flame sensing Boron-doped diamond Schottky photodiode

Superb Strengthening Effect of Net-Like Distributed Amorphous Al_(2)O_(3)on Creep Resistance of(B_(4)C+Al_(2)O_(3))/Al Neutron-Absorbing Materials

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Acta Metallurgica Sinica(English Letters) 2022年第12期35卷 2007-2013页

作者： y.N.Zan X.Lei J.F.Zhang D.Wang Q.Z.Wang B.L.Xiao Z.y.Ma Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.LtdBejing 100840China

B4C reinforced Al composites are widely used as neutron absorbing materials(NAMs)due to excellent neutron absorbing efficiency,however,such NAMs exhibit poor high-temperature *** meet the requirement for structure-function integration,NAMs with enhanced high-temperature mechanical properties are *** this work,a novel(B4 C+Al_(2)O_(3))/Al NAM with netlike distribution of Al_(2)O_(3)was fabricated by powder metallurgy method and subjected to high-temperature tensile creep *** was shown that the creep resistance was enhanced by several orders of magnitude via the addition of only2.1 vol.%netlike-distributed Al_(2)O_(3).(B_(4)C+Al_(2)O_(3))/Al exhibited high apparent stress exponents ranging from 16 to 25 and high apparent activation energy of 364 kJ/*** creep behaviour could be rationalized using the substructure-invariant model and its rupture behaviour could be described by the Dobes-Milicka equation.

关键词： Neutron absorber material Al matrix composite Tensile creep B_(4)C/Al

INVESTIGATION ON TWO-BODy WEAR OF AUSTENITIC MANGANESE STEEL THROUGH NUMERICAL QUADRATURE

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 307-310页

作者： J.P.Xie H.L.yuan A.Q.Wang W.y.Wang y.R.Zhao School of Materials Science and Engineering Henan University of Science and Technology Luoyang 471003 China China International Trust and Investment corporation Heavy Machinery.co. Ltd. Luoyang 471003China

The mathematic calculation on two--body wear of austenitic manganese steel has been performed by means of the elastic contact theory,stress interferometer and *** distribution in contacted area was calculated and the mechanism on two--body wear has been investigated through numerical *** show that two--body wear is mainly plowing wear the cracks of abrasive dust originates from the region between 0.2αand 0.5α(αis radius of contacted round).Driving force to make crack extension along y axis is T_(yzmax)and extension direction is 45°with *** forces to make crack extension along x axis is alternativeσ_x and T_(yzmax),the direction of crack extension is 37°with horizon.

关键词： mathematic calculation manganese steel two-body wear

SPECIFIC DEGRADATION OF WATERSHEDS

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International Journal of Sediment Research 2007年第2期22卷 114-119页

作者： Boubacar KANE Pierre y.JULIEN Central Director of Water Energie du Mali S.A.formerly of Colorado State UniversityFort CollinsCO80523U. S. A Engineering Research Center Colorado State UniversityFort CollinsCO 80523U.S.A.

An extensive database of reservoir sedimentation surveys throughout continental United States is compiled and analyzed to determine specific degradation SD relationships as function of mean annual rainfall R, drainage area A, and watershed slope S. The database contains 1463 field measurements and specific degradation relationships are defined as function of A, R and S. Weak trends and significant variability in the data are noticeable. Specific degradation measurements are log normally distributed with respect to R, A, and S and 95% confidence intervals are determined accordingly. The accuracy of the predictions does not significantly increase as more independent variables are added to the regression analyses.

关键词： Specific degradation Sediment yield Reservoir sedimentation

Jichengite 3CuIr_2S_4·(Ni,Fe)_9S_8,a New Mineral,and Its Crystal Structure

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Acta Geologica Sinica(English Edition) 2011年第5期85卷 1022-1027页

作者： Zuxiang yü Ziguo HAO Hanggen WANG Shuping yIN Jianhui CAI Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China Chemical Academy of Nankai University Tianjin 300071 China *correspondence: corresponding author. E-mail: yuzuxiang001@***

A new mineral,jichengite ideally 3CuIr_2S_4·(Ni,Fe)_9S_8,was found as a constituent of placer concentrates at a branch of the Luanhe River,about 220 km NNE of *** associated minerals are chromite,magnetite,ilmenite,zircon,native gold,iridium,ferrian platinum and *** placer is distributed at places around ultrabasic rock,which hosts chromite orebodies,from which PGM *** occurs commonly as massive or granular *** perfect morphology of jichengite was *** is steel gray and opaque with metallic luster and black *** has a Mohs hardness of 5,VHN(d) urn 21.65,H_m 4.465,Hv = 268.1 N/um^*** is brittle and weakly magnetic. Cleavage {010} is rarely *** fracture was *** could not be measured because of its too small grain ***(calc.) is 7.003 g/cm^*** light is reddish-brown,without internal *** is distinct with grayish or yellowish white in crossed nicols and bluish violetcopper red in uncrossed *** shows weak pleochroism and strong *** reflectance values in air at the Standard commission on Ore Mineralogy wavelengths are:38.9,34.3 at 470 nm,38.9,34.5 at 546 nm,39.1,35.3 at 590 nm,39.2,36.8 at 650 nm,parallel-axial *** six strongest lines in the X-ray powder-diffraction pattern[d in A,(I),(hkl)]are:3.00(100)(116),2.80(50) (205),2.48.(50)(208),1.916(40)(2,1,10),1.765(60)(220),1.753(50)(2,0,16).Five chemical analyses carried out,yielding the following results:S 25.76(25.49-5.97),Fe 10.03(9.78-10.31),co 0.78 (0.75-0.81),Ni 12.48(12.32-12.85),Cu 4.77(4.69-4.83),Ir 46.98(46.14-47.89),sum 100.80wt%,which produced a formula(Cu_(1.556)Fe_(0.976))_(2.532)(Ir_(5.063)S_(10.126))·(Fe_(2.7451)Ni_(4.404)co_(0.273))_(7.422)S_(6.517).The ideal formula is X_(10)Ir_5S_(17.5),which was calculated by single crystal structure analyses,where X=Cu(Ⅱ)+Fe(Ⅱ)+Ni(Ⅱ) +co(Ⅱ).The single crystal data were collected using a diffractometer with Mo Kαradiation a

关键词： jichengite crystal structure mineral

Oxidation of diesel soot on binary oxide Cu Cr(co)-based monoliths

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Journal of Environmental Sciences 2015年第2期27卷 171-177页

作者： Sergiy O.Soloviev Andriy y.Kapran yaroslava P.Kurylets L.V.Pisarzhevskii Institute of Physical Chemistry National Academy of Sciences of Ukraine

Binary oxide systems（Cu Cr2O4, Cu co2O4）, deposited onto cordierite monoliths of honeycomb structure with a second support（finely dispersed Al2O3）, were prepared as filters for catalytic combustion of diesel soot using internal combustion engine’s gas exhausts（O2, NOx, H2 O, co2） and O3 as oxidizing agents. It is shown that the second support increases soot capacity of aforementioned filters, and causes dispersion of the particles of spinel phases as active components enhancing thereby catalyst activity and selectivity of soot combustion to co2. Oxidants used can be arranged with reference to decreasing their activity in a following series： O3 NO2〉 H2 O 〉 NO 〉 O2〉 co2. Ozone proved to be the most efficient oxidizing agent： the diesel soot combustion by O3 occurs intensively（in the presence of copper chromite based catalyst） even at closing to ambient *** obtained give a basis for the conclusion that using a catalytic coating on soot filters in the form of aforementioned binary oxide systems and ozone as the initiator of the oxidation processes is a promising approach in solving the problem of comprehensive purification of automotive exhaust gases at relatively low temperatures, known as the ＂cold start＂ problem.

关键词： Catalyzed diesel particulate filters Cu Cr2O4 Cu co2O4catalytic coatings cordierite monoliths Second support Oxidizing agents Ozone

Structural and optical studies of yb^(3+),Er^(3+) and Er^(3+)/yb^(3+) co-doped phosphate glasses

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Journal of Rare Earths 2013年第7期31卷 685-693页

作者： S.Hraiech M.Ferid y.Guyot G.Boulon Physical Chemistry Laboratory of Mineral Materials and Their Applications National Center of Research in Materials ScienceTechnologic Park of Borj Cedria B.P.738020 SolimanTunisia Physical Chemistry of Luminescent Materials(LPCML) University of LyonClaude Bernard/Lyon 1 UniversityUMR 5620 CNRSLa Doua69622 VilleurbanneFrance

Phosphate glass samples with various yb2O3 and Er2O3 contents were synthesized by the conventional melt quenching technique and characterized by X-ray diffraction, IR absorption spectroscopy and Raman scattering spectroscopy. The absorption, emission spectra and fluorescence decay studies were carried out both at low and room temperatures. Results showed the existence of several sites occupied by the rare earth ions in the phosphate glass. Up-conversion and cooperative fluorescence were also discussed.

关键词： yb3+/Er3+ co-doped phosphate glass energy transfer upconversion co-operative fluorescence rare earths

Spatio-Temporal Effect on Soil Respiration in Fine-Scale Patches in a Desert Ecosystem

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Pedosphere 2006年第1期16卷 1-9页

作者： S. PEN-MOURATOV M. RAKHIMBAEV y. STEINBERGER Faculty of Life Sciences Bar-Ilan University Ramat-Gan 52900 (Israel) Faculty of Life Sciences Bar-Ilan University Ramat-Gan 52900 (Israel) Institute of Botany Tashkent (Uzbekistan)

Soil organisms in terrestrial systems are unevenly distributed in time and space, and often aggregated. Spatiotemporal patchiness in the soil environment is thought to be crucial for the maintenance of soil biodiversity, providing diverse microhabitats tightly interweaving with resource partitioning. Determination of a ＂scale unit＂ to help understand ecological processes has become one of the important and most debatable problems in recent years. A fieldwork was carried out in the northern Negev Desert highland, Israel to determine the influence of fine-scale landscape patch moisture heterogeneity on biogeochemical variables and microbial activity linkage in a desert ecosystem. The results showed that the spatio-temporal patchiness of soil moisture to which we attribute influential properties, was found to become more heterogenic with the decrease in soil moisture availability （from 8.2 to 0.4 g kg^-1） toward the hot, dry seasons, with coefficient of variation （CV） change amounting to 66.9%. Spatio-temporal distribution of organic matter （OM） and total soluble nitrogen （TSN） was found to be relatively uniformly distributed throughout the wet seasons （winter and spring）, with increase of relatively high heterogeneity toward the dry seasons （from 0.25% to 2.17% for OM, and from 0 to 10.2 mg kg^-1 for TSN） with CV of 47.4% and 99.7% for OM and TSN, respectively. Different spatio-temporal landscape patterns were obtained for Ca （CV = 44.6%）, K （CV = 34.4%）, and Na （CV = 92%） ions throughout the study period. co2 evolution （CV = 48.6%） was found to be of lower heterogeneity （varying between 2 and 39 g co2-C g^-1 dry soil h^-1） in the moist seasons, e.g., winter and spring, with lower values of respiration coupled with high heterogeneity of Na^＋ and low levels of TSN and organic matter content, and with more homogeneity in the dry seasons （varying between 1 and 50 g co2-C g^-1 dry soil h^-1）. Our results elucidate the heterogeneity and complexity of desert system habitats

关键词： desert microbial respiration patchiness small-scale habitat soil