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
FU Tian-liang
钢铁研究学报(英文版)
Based on exploring quenching mechanism, three types of medium-low carbon steel and low-alloy construction steel’s quenching critical cooling rate models were established, respectively speaking, modified Maynier model, Eldis model and isothermal curve model. During construction process, regression analysis and Newton interpolation method were used for higher calculated precision. Through comparing and analyzing, the superior one was singled out to evaluate the full hardening thickness after quenching. According to hardness analyzing, the deviation between predicted hardness distribution and the experimental value is within 6%.
关键词:
medium and low carbon steel;low-alloy construction steel;critical cooling rate;hardenability
SUN Wenqiang
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CAI Jiuju
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MAO Hujun
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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
XIAN Aiping LI Peiji CHEN Wenxiu WANG Yikang Institute of Metal Research
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Academia Sinica
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Shenyang
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ChinaCHEN Renvi MEI Dongsheng Panzhihua Institute of Iron and Steel Research
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Ministry of Metallurgical Industry
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Panzhihua
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China associate professor
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Institute of Metal Research
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Academia Sinica
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Shenyang 110015
,
China
金属学报(英文版)
The determination of dffusible hydrogen in U71Mn heavy rail steel,and hydrogen diffusivity as well as the hydrogen distribution in the cross section of blooms with stack cooling were stu- died.The results showed that,most of the hydrogen in blooms of heavv rail steel is diffusible, the hydrogen diffusivity in U71Mn rail steel blooms at room temperature is(0.85—1.02)× 10~(-6)cm~2/s,after stack cooling,the hydrogen content in bloom will decrease greatly which is helpful to form the flake-free phenomenon in the heavy rail produced by Panzhihua Iron and Steel Company.
关键词:
rail steel
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