S. X. Wang
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D. S. Zheng and Y. L. Liu 1) Department of Material Engineering
,
Luoyang Institute of Technology
,
Luoyang 471039
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China 2) Luoyang Copper (Group) Co.
,
Ltd
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Luoyang
,
China
金属学报(英文版)
The model established in this paper for calculating the unsteady temperature field, in which physical parameters varies with temperatures, is simplified as compared with the classical one by defining the heat conductivity as function of temperature and dealing with the latent heat of phase transformation and boundary conditions. The results show that the probability of absolute error less 2℃ between the calculated and measured values in temperature field calculation reaches above 80%.
关键词:
temperature field
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null
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null
S. X. Wanng
,
D. S. Zheng
,
Y. L. Liu 1) Department of Material Engineering
,
Luoyang Institute of Technology
,
Luoyang 471039
,
China 2) Luoyang Copper (Group) Co.
,
Ltd
,
Luoyang
,
China
金属学报(英文版)
As far as the accuracy of calculating unsteady temperature field is concerned, it is very important to find the accurate physical parameters such as specific heat, thermal conductivity, latent heat of phase transformation and surface heat flux. The model for calculating H and Q is established in this paper. The measurement methods and data processing for physical parameters such as volume specific heat C, thermal conductivity k, volume latent heat of phase transformation c1 and surface heat flux are introduced The physical parameters of 1Cr18Ni9Ti and 45 steels and the surface heat flux for 1 Cr18Ni9Ti probe cooled in water,10% NaCl water and oil with different temperatures are measured, respectively. These data show that the probability of absolute error less than 2* C between the calculated and measured values in temperature field calculation reaches above 80% if using the above physical parameters, which provides a reliable technology basis for precise calculation of temperature field.
关键词:
unsteady temperature field
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null
Corrosion Engineering Science and Technology
Four kinds of imidazoline inhibitors with different hydrophilic group, i.e. carboxymertyl imidazoline (CMI-11), hydroxyethyl imidazoline (HEI-11), aminoethyl imidazoline (AEI-11) and imidazoline (IM-11) had been synthesised and characterised by infrared and ultraviolet spectra. The inhibition performance of these imidazoline inhibitors for CO(2) corrosion of N80 in 3%NaCl solution was investigated through linear polarisation resistance, polarisation curve and electrochemical impedance spectroscopy. In order to study the relationship between the molecular structure and inhibition properties of these imidazoline inhibitors, quantum chemical calculations have been also applied. The results showed that the presence of a hydrophilic group was beneficial to the corrosion inhibition properties of these imidazoline inhibitors, and the inhibition efficiency follows the order: CMI-11 > HEI-11 > AEI-11 > IM-11. The calculated quantum chemical parameters supported that the lower the lowest unoccupied and highest occupied molecular orbital energy gap, the higher the inhibition efficiency. The theoretical calculation was in good agreement with experimental results.
关键词:
carbon dioxide corrosion;corrosion inhibitor;imidazoline;hydrophilic;group;quantum chemical calculation;mild-steel;acidic media;impedance spectroscopy;molecular-structure;painted metals;eis;derivatives;efficiency
SUN Wenqiang
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CAI Jiuju
,
MAO Hujun
,
GUAN Duojiao
钢铁研究学报(英文版)
As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.
关键词:
CO2 emissions
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energy use
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LMDI technique
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steel production
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energy consumption
Electrochimica Acta
The inhibition by 2-mercaptobenzoxazole (MBO) of copper corrosion in NaCl solution was investigated by means of potentiodynamic polarization, STM: QCM, XPS, FTIR and AES. The inhibition efficiency depended on MBO concentration, existence of NaCl and the immersion period of the copper sample. The inhibition efficiency of about 99% could be obtained by immersing for above 20 h in 3% NaCl + 1 mM MBO solution. The surface of the copper sample immersed in NaCl + MBO solution possessed FTIR characteristics different from those of MBO solution, irrespective of immersion time. The in-situ STM morphologies showed the rapid formation of a three-dimensional compact inhibition film on the surface of copper in MBO solution containing NaCl. XPS indicated that the inhibition film was cuprous and the chemical environments of S and N atoms were evidently changed. It is concluded that MBO reacted with the cuprous species from the corrosion process, and produced a water-insoluble cuprous complex to form the inhibition film and to retard the corrosion of copper. (C) 2000 Elsevier Science Ltd. All rights reserved.
关键词:
corrosion inhibition;copper;2-mercaptobenzoxazole;STM;QCM;heterocyclic-compounds;chloride media;benzotriazole;efficiency;electrode;behavior;films;sers;xps;cu
American Mineralogist
A natural high-pressure phase of titanium oxide with alpha-PbO2-structure has been found in omphacite from coesite-bearing eclogite at Shima in the Dabie Mountains, China. High-resolution transmission electron microscope observations have revealed an orthorhombic lattice, corresponding to alpha-PbO2-type TiO2, with cell parameters a = 0.461 nm, b = 0.540 nm, c = 0.497 nm and space group Pbcn. It occurs as nanometer-thick (< 2 nm) lamellae between multiple twinned rutile crystals, providing additional evidence of very high-pressure, metamorphism at 7 GPa, 900 degrees C. This implies subduction of continental material to a depth of more than 200 kilometers. alpha-PbO-type TiO2 could be an extremely useful index mineral for ultrahigh-pressure.
关键词:
high-pressure phase;ries crater;rutile;polymorph;titanium
Materials Science and Technology
kThe compound Ti3SiC2 is a promising reinforcement for copper, but at a high volume content of Ti3SiC2, densification of Cu/Ti3SiC2 composites becomes difficult. To improve the densification behaviour and microstructure of Cu/Ti3SiC2 composites, Ti3SiC2 particulates were coated with a layer of copper by an electroless plating method before being incorporated into the copper matrix. Results demonstrated that, compared with uncoated Ti3SiC2 reinforced copper, copper coated Ti3SiC2 reinforced composites exhibit both high density and a homogeneous distribution of Ti3SiC2 within the copper matrix. The precoated layer of copper prevents direct contact and agglomeration of Ti3SiC2 particulates. Owing to the improved density and microstructure, the mechanical properties of Cu/Ti3SiC2 composites are also enhanced. Mechanical property investigation revealed that a significant strengthening effect is observed for Cu/Ti3SiC2 composites at both room and high temperatures.
关键词:
metal matrix composites;particulate composites;copper alloys;titanium;compounds;mechanical properties;titanium-silicon carbide
Scripta Materialia
The alloying effect of Mo, Ta and platinum group metals on the properties of gamma'-Co(3)(Al, W) are studied using supercell models. It is demonstrated that Mo, Ta, Rh Ir and Pt can stabilize the gamma' phase, and three types of site preference are recognized. The binding energy and the lattice constant of the gamma' phase is modified and the distinct alloying effect of those elements is further revealed by investigating the impurity-induced charge density and the partial density of states. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
关键词:
Platinum group;Electronic structure;Density functional;Co-based;alloys;ni3al;substitution;temperature;superalloys
Suzan A.Ali
材料科学技术（英文）
Twelve samples of Co-Cu/Al2O3 were prepared by impregnating Al2O3 with cobalt salt followed by copper salt or vice versa. The composition of the prepared samples varied in the molar ratios 1:1, 1:2 and 1:3 with respect to CuO:CoO or CoO:CuO, while Al2O3 content was kept at about 13-15 mol. The prepared solids were calcined at different temperatures and the products were characterized by means of XRD-analysis. The catalytic activity of the calcined solids was tested in H2O2 decomposition. The XRD-analysis revealed that the sequence of impregnation affects much the structure of the samples. The loading of alumina with cobalt followed by copper salts produced sample with structure differs from that for sample firstly treated with copper followed by cobalt salts. XRD- analysis showed the formation of crystalline spinel Co1-x Cux Al2O4 with nearly the same crystal structure as CoAl2O4 even with high copper content. The examination of catalytic activity of these samples showed that catalysts with Co-loaded over Cu were more active than catalysts with Cu loaded over Co. In all cases the double oxides loaded over Al2O3 were more active than the single oxide over Al2O3.
关键词:
Catalysis
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null
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null
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null
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null
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