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Influence of nanometric CeO2 coating on high temperature oxidation of Cr

Progress in Natural Science:materials international 2007年第5期17卷 601-606页

作者： Jin Huiming , Zhang Linnan and Liu Xiaojun (materials Research center, Department of Mechanical Engineering, Yangzhou University, Yangzhou 225009, china College of materials Science and Engineering, North-East University, shenyang 110014, china) [a]materials Research center Department of Mechanical Engineering Yangzhou University Yangzhou China [b]College of materials Science and Engineering North-East University Shenyang China

Isothermal and cyclic oxidation behavior of chromium and its superficially applied nanometric CeO2 samples were studied at 900℃in air. Scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and high resolution electronic microscopy (HREM) were used to examine the morphology and micro-structure of oxide films. It was found that ceria addition greatly improved the anti-oxidation ability of Cr both in isothermal and cyclic oxidizing experiments. Acoustic emission (AE) technique was used in situ to monitor the cracking and spalling of oxide films, and AE signals were analyzed in time-domain and number-domain according to the related oxide fracture model. Laser Raman spectrometer was also used to study the stress status of oxide films formed on Cr with and without ceria. The main reason for the improvement in anti-oxidation of chromium was that ceria greatly reduced the growing speed and grain size of Cr2O3. This fine-grained Cr2O3 oxide film might have better high temperature plasticity and could relieve parts of compressive stress by means of creeping, and maintained the ridge character and relatively low internal stress level. Meanwhile, ceria application reduced the size and the number of interfacial defects, while remarkably enhanced the adhesive property of Cr2O3 oxide scale formed on Cr substrate.

关键词： oxidation stress CeO2 nanoparticle coating chromium.

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Microstructure and Mechanical Properties of Dy-α-sialon/Nano-size SiC Composites

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Journal of materials Science & Technology 1997年第4期13卷 336-338页

作者： Danyu JIANG Chen ZHANG Jianlin SHI Tingrong LAI and Dongsheng YAN(Shanghai Institute of Ceramics, chinese academy of sciences, Shanghai 200050, china) Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

The composite of Dy-α-sialon/10 wt pct nano-size SiC particles has been prepared from precursor powders of Si3N4, AIN, Al2O3, Dy2O3 and nano-size β-SiC. The hardness, toughness and bending strength of the composite at ambient temperature are a little higher than those of Dy-α-*** the bending strength is maintained up to 1000℃ and about 2 times more than that of Dy-α-sialon at the same temperature. The fracture surfaces show that the grain size of the composite is smaller than that of Dy-α-sialon, and both Of them have predominately transgranular mode of fracture. It is believed that the decrease of the bending strength of Dy-α-sialon at elevated temperature is caused by the viscous flow of the grain boundary phase, while the addition of nanosize SiC particles effectively increases the viscosity of the grain boundary phase and therefore prevents the strength loss of Dy-α-sialon/nano-size SiC composites at elevated temperature

关键词： Microstructure and Mechanical Properties of Dy sialon/Nano-size SiC Composites SiC Nano

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Isotopic compositions of small shelly fossil Anabarites from Lower Cambrian in Yangtze Platform of South china: Implications for palaeocean temperature

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Progress in Natural Science:materials international 2007年第10期17卷 1185-1191页

作者： Chen Yongquan1,2, Jiang Shaoyong1, Ling Hongfei1, Yang Jinghong1 and Wan Defan3(1. State Key Laboatory for Mineral Deposits Research and center for Marine Geochemistry Research, Department of Earth sciences, Nanjing University, Nanjing 210093, china 2. Tarim Oilfield Company Exploration & Development Research Institute, Ku’erle 841000, china 3. Institute of Mineral Resources, chinese academy of Geological sciences, Beijing 100037, china) State Key Laboatory for Mineral Deposits Research and center for Marine Geochemistry Research Department of Earth Sciences Nanjing University Nanjing 210093 China arim Oilfield Company Exploration & Development Research Institute Ku’erle 841000 China Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 100037 China

Anabarites belong to small shelly fossils (SSF), which occur widely in the Lower Cambrian strata of Yangtze Platform in South china. They are phosphate shell in composition and represent the earliest stage of the Cambrian bioradiation of Bilateria, the so-called "Cambrian Explosion". In this study, we attempted to separate Anabarites fossils from Lower Cambrian dolostones, and we obtained samples of both the fossils (SSF) and the granular phosphates (GP). Isotopic analyses were performed on samples of SSF, GP, and matrix dolostone (DH-23). The results showed that the δ30Si values of the quartz filling in fossils celoms, and the siliceous materials in granular phosphates are -0.6‰ and -0.7‰, which is different from normal sedimentary siliceous rocks from the Lower Cambrian strata (0—0.7‰) as reported by Li et al., but is consistent with the data for siliceous rocks and cherts of submarine hydrothermal origin. It is likely that a later hydrothermal replacement could have taken place in the SSF-bearing sedimentary rocks. The oxygen isotope values of the phosphate of SSF and GP are 16.8‰ and 17.0‰, respectively. These are significantly higher than the Neoproterozoic phosphate ores (10.9‰—13.9‰) as reported by Ling et al., hence, late diagenesis and hydrothermal replacement may not have caused a significant change in the oxygen isotope compositions of the small shelly fossils, and the calculated temperatures (25.4—26.3℃) for palaeo-seawater using a SSF phosphate oxygen isotope thermometer are therefore considered here as the upper limit of seawater temperature in the Early Cambrian ocean of the Yangtze Platform.

关键词： Anabarites oxygen isotope silicon isotope paleo-temperature.

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THE SYNERGISTIC INHIBITION STUDIES OF SEVERAL AMINES AND CHLORIDE ION ON IRON IN THE ACIDIC PERCHLORIDE SOLUTIONS

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 952-957页

作者： J.H.Dong 1) ,J.Y.Chen 2,3) and. C.N.Cao 1) 1) State Key Laboratory for Corrosion and Protection of Metals, Institute of Corrosion and Protection of Metals, The chinese academy of sciences, shenyang 110015, china 2) The international center

The effect of chloride ion on the corrosion inhibition of iron caused by dencylamine(DA), dipentylamine(DDA) and dodecylamine(DPA) has been investigated by measuring the inhibitory coefficients for the anodic and cathodic processes at corrosion potential. It has been shown that the major synergistic inhibition effects between amines and chloride ions occur in the cathodic process, very weak in the anodic process. The anodic inhibition mechanism follows the competing adsorptive model, while the cathodic inhibition mechanism follows the cooperative adsorptive model.

关键词： synergistic inhibition organic amine chloride ion

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Characterization of Nanocrystallizatin Surface Layer of 0.4C-1Cr Low Alloy Steel Prepared by Ultrasonic Particulate Peening

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材料热处理学报 2004年第5B期25卷 1257-1259页

作者： ZHANGJun-bao LIUYu-liang ZHAOXin-qi WUJie SONGHong-wei XIONGTian-ying BaosteelTechnologycenter BaoshanIron＆SteelCO.LTD.ShanghaiChina InstituteofMetalResearch ChineseAcademyofSciencesShenyangChina

A nanostructured surface layer was fabricated in a quenched and tempered 0.4C-lCr low alloy steel by ultrasonic particulate peening technique. The microstructure of the nanocrystalline surface layer was characterized by means of TEM and Mossbauer spectroscopy. Experimental results reveal that both cementite and ferrite nanocrystals with an average size of 5 nm were formed in the surface layer of the steel, phase transformation of austenite and dissolution of cementite maybe occur in the process of ultrasonic paniculate peening.

关键词：显微结构超声波喷丸处理表面毫微结晶 0.4C-1Cr低合金钢

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Nonlinear Excitation and Dynamic Features of Deoxyribonucleic Acid (DNA) Molecules

Nonlinear Excitation and Dynamic Features of Deoxyribonuclei...

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2008年全国生物化学与分子生物学学术大会

作者： Xiao-feng Pang (Institute of Life Sceinee and Yechnplogy,University of Electronic Science and Technology of china,Chengdu 610065,P.R.china international center for materials physics,chinese academy of sciences,shenyang 110015)

The structure of DNA and its biological function have been one of the most fascinating problem of modern biophysics,much attentions to it have been paid up to now because it is at the basis of *** idea that nonlinear ...

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Study on Sulfide-melt Inclusions in Mantle Xenoliths of Xinchang, Zhejiang

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international Journal of Minerals,Metallurgy and materials 2000年第1期14卷 5-9页

作者： Jiuhua Xu Xuelei Chu YulingXie Fenglei Bie Dayi Qian University of Science and Technology Beijing, Beijing 100083, china china University of Geosciences, Beijing 100083, china The Research center of Mineral Resources Exploration, chinese academy Univ Sci & Technol Beijing Beijing 100083 Peoples R China china Univ Geosci Beijing 100083 Peoples R China chinese Acad Sci Res Ctr Mineral Resources Explorat Beijing 100101 Peoples R China chinese Acad Sci Inst Geol Beijing 100029 Peoples R China

In minerals of mantle xenoliths captured within Tertiary alkali-basalt from Xinchang, Zhejiang province, china, many sulfidemelt inclusions were found by the observation of polished thin section. Electron microprobe analysis has been applied to detect the components of sulfide-melt inclusions. The result shows that the sulfide phases of inclusions are mainly pentlandite, and secondarily pyrrho- tite, The molar ratio of Ni to Fe, r_Ni,/r_Fe, of mineral phases in sulfide inclusions is related to olivine contents in host mantle xenoliths. The r_Ni/r_Ni, of sulfides from Xinchang samples has a possitive correlation to r_(Fe+Ni),/r_S. The r_(Fe+Ni),/r_S, becomes higher with the increasing of r_Ni/r_Fe In single sulfide-melt inclusions, r_Ni,/r_Fe, r_(Fe+Ni),/r, and Ni contents increase from the center to edge, reflecting a result of different cooling speed in an inclusion. A comparison between the data from Hannuoba, West Eifel of Germany and Nograd-Gomor of east Europe suggests that the composition of the inclusions is different for each area, which indicated that a regional differentiation of sulfide in mantle fluids.

关键词： mantle xenolith sulfide-melt inclusion electron microprobe analysis, Xinchang

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STRUCTURE OF Al-Mn-Zn-Mg ALLOY POWDER

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Acta Metallurgica Sinica(English Letters) 1996年第2期9卷 79-84页

作者： WU Lijun ZHAO Lihua YANG Qiaoqin LI Shaolu LI Xieqian(materials Research and Test Centre,Hunan University,Changsha 410082,china)(Laboratory of Atomic Imaging of Solids,Institute of Metal Research, chinese academy of sciences,shenyang 110015,china)

The structure of Al-Mn-Zn-Mg alloy powder annealed at 800℃ has been studied by transmisston electron microscopy(TEM).An approximant phase(named as C-phase) to the decagonal phase was found and its crystal structure was determined It belongs to c-center orthorhombic lattice with a=2.35 nm,b=3.27 nm and c=1.22 *** stillfound a hexagonal phase with a=0.7) nm and c=0.79 nm,(named as phase) in the annealed alloy *** annealed alloy powder is composed of the C-phase,the phase,the decagonal phase and Al solid solution.

关键词： quasicrystal crystalline structure Al-Mn-Zn-Mg alloy powder

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ZrO2 strengthened NiAl/Cr(Mo,Hf) composite fabricated by powder metallurgy

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Progress in Natural Science:materials international 2012年第3期22卷 231-236页

作者： L.Y. Sheng a,b, J.T. Guo c, T.F. Xi a,b, B.C. Zhang c, H.Q. Ye c a PKU-HKUST ShenZhen-Hong Kong Institution, Shenzhen 518057, china b College of Engineering, Peking University, Beijing 100871, china c Institute of Metal Research, chinese academy of sciences, shenyang 110016, china [a] PKU-HKUST ShenZhen-Hong Kong Institution Shenzhen 518057 China [b] College of Engineering Peking University Beijing 100871 China [c] Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The ZrO2 ceramic particles strengthened NiAl/Cr(Mo,Hf) composite was fabricated from the rapidly solidified NiAl/Cr(Mo,Hf) pre-alloyed powder and the ZrO2 powder by powder metallurgy technique. Microstructure examination revealed that in the prepared composite NiAl and Cr(Mo) phases distributed at the eutectic cell boundary become coarse but many Cr(Mo) platelets inside the eutectic cell were broken, which was different from the original powder. Moreover, fine Ni2AlHf and Hf solid solution particles distributed uniformly in the composite, and the ZrO2 particles mainly segregated along eutectic cell boundary. In addition, twin crystal and stacking faults were observed inside of ZrO2 grains. The experimental results showed that the ZrO2 ceramic particles strengthened NiAl/Cr(Mo,Hf) composite exhibited better room temperature and high temperature mechanical properties than the NiAl/Cr(Mo,Hf) alloy, which may be attributed to the fine structure and the strengthening effect of ZrO2 particles.

关键词： NiAl intermetallics NiAl/Cr(Mo) composite Powder metallurgy ZrO2 strengthening

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PLS path model building:A multivariate approach to land price studies-A case study in Beijing

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Progress in Natural Science:materials international 2009年第11期19卷 1643-1649页

作者： Wenjie Wu~(a,b),Wenzhong Zhang~(a,*) a Institute of Geographic sciences and Natural Resources Research,CAS,Beijing 100101,china b Graduate University of chinese academy of sciences,Beijing 100049,china Institute of Geographic sciences and Natural Resources Research CAS Beijing 100101 China Graduate University of chinese academy of sciences Beijing 100049 China

Previous studies have revealed that statistical methods can be used to analyze land-leasing parcel ***,the conventional statistical methods used in land analysis have some limitations,especially in cases of limited observational *** this paper,with the help of geographic information system(GIS) techniques,a partial least squares(PLS) path model is applied to study the relationship between residential land prices and various determinants through a case study of Beijing in *** a preliminary analysis,four latent variables are selected:accessibility of the workplace center,livability,traffic,and environment *** results show that the observation variables have a strong explanatory power for their corresponding latent variables,and the four latent variables have varying impacts on residential land *** the latent variables,accessibility to the workplace center has the strongest impact on the residential land price.

关键词： Land PLS path model GIS Beijing

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