To investigate the effect of nitrogen (N) level on iron (Fe) content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes....To investigate the effect of nitrogen (N) level on iron (Fe) content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes. In addition to the genotypic differences of iron content in milled rice, grain yield, 1000-grain weight and N content in grains under the same N level, there were also variations in the response of Fe content in milled rice to N levels. Based on the range and variation coefficient of Fe content in milled rice under the three N levels, the response of Fe content in milled rice to N levels could be classified into four types including highly insensitive, insensitive, sensitive and highly sensitive types. A significant quadratic correlation was found between the Fe content in milled rice and 1000-grain weight or the N content in grains. However, no significant correlation between the Fe content in milled rice and grain yield was detected. In conclusion, there are genotypic differences in the effects of N levels on Fe content in milled rice, which is favorable to breeding of Fe-rich rice under different N environments. Furthermore, high yield and Fe-rich rice could be grown through the regulation of nitrogen on Fe content in milled rice, 1000-grain weight and N content in milled rice.展开更多
At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manua...At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manually calculated and input in a computer.With the aid of a communication program between an AAS and an electronic balance(EB),the above process can be modified.First,the mass of a sample is sent to a computer by the EB.Second,the mass of the coating is calculated by the computer automatically.Finally,the iron mass is uploaded to the communication program,and the iron content can also be calculated automatically.As such,the modified process is more efficient.展开更多
The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest...The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest accuracy.However,this method presents low detection efficiency and is thus unsuitable for production quality control.Fundamental parameter and empirical coefficient methods in XRF can be used for the quality control of iron content in the galvanized coating of zinc-iron alloys.The repeatability of the two XRF methods was 0.2%and 0.4%,respectively,which were better than that of the chemical method(0.6%).However,the two XRF methods have their own limitations.The accuracy of the two XRF methods depends on the process stability of different units and may be poorer than that of the chemical method.Thus,the use of the two XRF methods should be carefully restricted.展开更多
The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectro...The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectrometry, sometimes it exceeds the quality control limit.Influences, such as current, voltage, equipment(internal circulating water, 10%CH4+90%Ar, and vacuum) checking, instrument monitoring, sample cleaning, and oper-ators, were investigated by means of 6-sigma and lean operations to improve accuracy.展开更多
The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption s...The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption spectrophotometry. The iron contents of bark extract of Acacia nilotica, Acacia senegal and Acacia seyal were 0.0044%, 0.0040% and 0.0029% respectively. In contrast, the iron content of bark extract of the three species of Acacia had lower percentage compared to that of Mimosa (Acacia mearnsii) (0.0047%), which was imported from Kenya. The iron content presented in leaves, barks, mature and immature fruits of Acacia species were determined by the same analytical methods. Bark and mature fruits of Acacia nilotica had the highest and equal percentage (0.1450%). The percentage of iron content of leaves and bark of Acacia seyal had equal percentage (0.0750%), while the bark of Acacia senegal had much lower percentage (0.0375%).展开更多
FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD)...FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.展开更多
Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sph...Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.展开更多
In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron micr...In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.展开更多
This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen...This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.展开更多
Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(...Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.展开更多
Heating-cooling combined mold(HCCM) horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The...Heating-cooling combined mold(HCCM) horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The effects of Fe content(1.08wt%–2.01wt%) on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.展开更多
Copper was surfaced on the Q235 substrate by shielded metal arc welding (SMAW) and tungsten inert-gas (TIG) arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning ele...Copper was surfaced on the Q235 substrate by shielded metal arc welding (SMAW) and tungsten inert-gas (TIG) arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers' numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.展开更多
A great amount of red mud generated from alumina production by Bayer process not only threatens the environment but also causes waste of secondary resources.High-iron-content red mud from Bayer process was employed to...A great amount of red mud generated from alumina production by Bayer process not only threatens the environment but also causes waste of secondary resources.High-iron-content red mud from Bayer process was employed to recover alumina and ferric oxide by the process of reduction-sintering,leaching and then magnetic beneficiation.Results of thermodynamic analyses show that ferric oxide should be reduced to Fe if reduction of ferric oxide and formation of sodium aluminate and calcium silicate happen simultaneously.Experimental results indicate that alumina recovery of Bayer red mud can reach 89.71%,and Fe recovery rate and the grade of magnetite concentrate are 60.67%and 61.78%,respectively,under the optimized sintering conditions.展开更多
This paper deals with an important role of silicon in producing ductile iron with quenched complex structure of bainite and martensite. The samples are cast in permanent mold and quenched in solution of sodium silicat...This paper deals with an important role of silicon in producing ductile iron with quenched complex structure of bainite and martensite. The samples are cast in permanent mold and quenched in solution of sodium silicate. The result of thc experiments shows that the austenizing temperature should rise with increasing silicon content, otherwise much undissolved ferrite is present in the matrix after quenching. However the undissolvec ferrite can be decreased greatly or even eliminated by adding appropriate amount of ooron. On this condition, the amount of bainite gets increasing and the amount of residual austenite decreasing with the silicon cortent increasing. An approach has also been made to the mechanism of the effect of silicon on the transformation of bainite in ductile iron. The T.T.T. curves measured show that the increase of sllicon content causes the curve to shift to the left. This is quite different from the fact in steel.展开更多
Simultaneous thermal analysis(STA) was used to investigate the effects of silicon content on the oxidation kinetics of silicon-containing steels under an atmosphere and heating procedures similar to those used in in...Simultaneous thermal analysis(STA) was used to investigate the effects of silicon content on the oxidation kinetics of silicon-containing steels under an atmosphere and heating procedures similar to those used in industrial reheating furnaces for the production of hot-rolled strips. Our results show that when the heating temperature was greater than the melting point of Fe2SiO4, the oxidation rates of steels with different silicon contents were the same; the total mass gain decreased with increasing silicon content, whereas it increased with increasing oxygen content. The oxidation rates for steels with different silicon contents were constant with respect to time under isothermal conditions. In addition, the starting oxidation temperature, the intense oxidation temperature, and the finishing oxidation temperature increased with increasing silicon content; the intense oxidation temperature had no correlation with the melting of Fe2SiO4. Moreover, the silicon distributed in two forms: as Fe2SiO4 at the interface between the innermost layer of oxide scale and the iron matrix, and as particles containing silicon in grains and grain boundaries in the iron matrix.展开更多
Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on...Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.展开更多
As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China' s...As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China' s current blast furnace method of producing pig low Ni iron with laterite, this study analyzed the technical characteristics and relevant problems of this process based on the discussion on the characteristics of laterite. The study aims to provide a reference for the better use of laterite in China.展开更多
AIM: To determine the plasmatic iron content and evaluate the oxidative stress(OS) markers in subjects receiving blood therapy.METHODS: Thirty-nine individuals with unspecified anemia receiving blood transfusions and ...AIM: To determine the plasmatic iron content and evaluate the oxidative stress(OS) markers in subjects receiving blood therapy.METHODS: Thirty-nine individuals with unspecified anemia receiving blood transfusions and 15 healthy subjects were included in the study. Anemic subjects were divided into three subgrou P:(1) those that received up to five blood transfusions(n = 14);(2) those that received from five to ten transfusions(n = 11); and(3) those that received more than ten transfusions(n = 14). Blood samples were collected by venous arm puncture and stored in tubes containing heparin. The plasma and cells were separated by centrifugation and subsequently used for analyses. Statistical analyses were performed using Kruskal-Wallis analysis of variance followed by Dunn's multiple comparison tests when appropriate.RESULTS: The eletrophoretic hemoglobin profiles of the subjects included in this study indicated that no patients presented with hemoglobinopathy. Labile plasmatic iron, ferritin, protein carbonyl, thiobarbituric acidreactive substances(TBARS) and dichlorofluorescein diacetate oxidation were significantly higher(P < 0.05), whereas total thiol levels were significantly lower(P < 0.05) in transfused subjects compared to controls. Additionally, the activity of catalase, superoxide dismutase and glutathione peroxidase were significantly lower in the transfused subjects(P < 0.05). Antioxidant enzyme activities and total thiol levels were positively correlated(P < 0.05), and negatively correlated with the levels of protein carbonyl and TBARS(P < 0.05). In contrast, protein carbonyl and TBARS were positively correlated(P < 0.05). Altogether, these data confirm the involvement of OS in patients following therapy with repeated blood transfusions.CONCLUSION: Our data reveal that changes in OS markers are correlated with levels of labile plasmatic iron and ferritin and the number of transfusions.展开更多
基金supported by the Key Projects in the National Science & Technology Pillar Program of China (Grant No. 2006BAD02A03)the National Natural Science Foundation of China (Grant Nos. 30971732 and 30671223)
文摘To investigate the effect of nitrogen (N) level on iron (Fe) content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm2 by using 120 rice genotypes. In addition to the genotypic differences of iron content in milled rice, grain yield, 1000-grain weight and N content in grains under the same N level, there were also variations in the response of Fe content in milled rice to N levels. Based on the range and variation coefficient of Fe content in milled rice under the three N levels, the response of Fe content in milled rice to N levels could be classified into four types including highly insensitive, insensitive, sensitive and highly sensitive types. A significant quadratic correlation was found between the Fe content in milled rice and 1000-grain weight or the N content in grains. However, no significant correlation between the Fe content in milled rice and grain yield was detected. In conclusion, there are genotypic differences in the effects of N levels on Fe content in milled rice, which is favorable to breeding of Fe-rich rice under different N environments. Furthermore, high yield and Fe-rich rice could be grown through the regulation of nitrogen on Fe content in milled rice, 1000-grain weight and N content in milled rice.
文摘At present,iron content in a galvanneal coating is determined by an atomic absorption spectrometer(AAS)in Baosteel.The mass of a sample is recorded by operators two times on paper,then the mass of the coating is manually calculated and input in a computer.With the aid of a communication program between an AAS and an electronic balance(EB),the above process can be modified.First,the mass of a sample is sent to a computer by the EB.Second,the mass of the coating is calculated by the computer automatically.Finally,the iron mass is uploaded to the communication program,and the iron content can also be calculated automatically.As such,the modified process is more efficient.
文摘The iron content in the galvanized coating of zinc-iron alloy was determined by atomic absorption spectrometry and two kinds of X-ray fluorescence(XRF)methods.Results show that the chemical method exhibits the highest accuracy.However,this method presents low detection efficiency and is thus unsuitable for production quality control.Fundamental parameter and empirical coefficient methods in XRF can be used for the quality control of iron content in the galvanized coating of zinc-iron alloys.The repeatability of the two XRF methods was 0.2%and 0.4%,respectively,which were better than that of the chemical method(0.6%).However,the two XRF methods have their own limitations.The accuracy of the two XRF methods depends on the process stability of different units and may be poorer than that of the chemical method.Thus,the use of the two XRF methods should be carefully restricted.
文摘The accuracy(repeatability and reproducibility) of the iron content analysis of galvanized coating using an X-ray fluorescence spectrometer with an L-spectrum is not better than that of flame atomic absorption spectrometry, sometimes it exceeds the quality control limit.Influences, such as current, voltage, equipment(internal circulating water, 10%CH4+90%Ar, and vacuum) checking, instrument monitoring, sample cleaning, and oper-ators, were investigated by means of 6-sigma and lean operations to improve accuracy.
文摘The amount iron content of the extracts and samples of Acacia species was determined. Since the iron hinders the process of retanning leather, iron content is determined by wet digestion method and atomic absorption spectrophotometry. The iron contents of bark extract of Acacia nilotica, Acacia senegal and Acacia seyal were 0.0044%, 0.0040% and 0.0029% respectively. In contrast, the iron content of bark extract of the three species of Acacia had lower percentage compared to that of Mimosa (Acacia mearnsii) (0.0047%), which was imported from Kenya. The iron content presented in leaves, barks, mature and immature fruits of Acacia species were determined by the same analytical methods. Bark and mature fruits of Acacia nilotica had the highest and equal percentage (0.1450%). The percentage of iron content of leaves and bark of Acacia seyal had equal percentage (0.0750%), while the bark of Acacia senegal had much lower percentage (0.0375%).
基金Project supported by the Natural Science Foundation of Jiangsu Province (BK20170232,BK20170238)National Natural Science Foundation of China (51908256)。
文摘FeCe nanocomposite catalysts with different iron contents were synthesized by a facile co-precipitation method.The as-prepared materials were characterized by various techniques including powder X-ray diffraction(XRD),N2 adsorption/desorption and high-resolution transmission electron microscopy(HRTEM).Catalyst with the highest iron content(90 FeCe) shows the best activity for the hydrogen generation via ammonia decomposition.83% NH3 conversion is achieved at 550℃ and nearly full conversion of NH3 is realized at 600℃ with a GHSV of 24000 cm3/(gcat·h).The large content and small size crystal particles of iron species are responsible for the good catalytic performance.Temperatureprogrammed reduction by hydrogen(H2-TPR) was performed to investigate the interaction between cerium and iron species.It is found that slight cerium can exert strong interaction with iron compound thus effectively prevent the self-aggregation of active iron species,so as to improve the catalytic activity for ammonia decomposition.
基金This work was supported by the National Natural Science Foundation of People’s Republic of China(No.NSFC52174246)the Interdisciplinary Scientific Research Foundation of Guangxi University(No.2022JCC016).
文摘Iron is an impurity widely occurred in sphalerite,and its effect on sphalerite flotation is complex.In this work,the effects of iron content and spin state on electronic properties and floatability of iron-bearing sphalerite are comprehensively studied using density functional theory Hubbard U(DFT+U)calculations combined with coordination chemistry flotation.The band gap of ideal sphalerite is 3.723 eV,and thus electron transition is difficult to occur,resulting in poor floatability.The results suggest the band gap of sphalerite decreases with increasing iron content.For low iron content,the decreased band gap facilitates electron transition;at this case,Fe^(2+)in a high-spin state possesses oneπelectron pair,which can form a weakπ-backbonding with xanthate,causing increasing floatability.However,for medium and high iron-bearing sphalerite,with the further decrease of band gap,Fe^(2+)is oxidized to Fe^(3+)due to electrochemical interaction,and henceπ-backbonding is eliminated,leading to lower floatability of iron-bearing sphalerite,which is consistent with the flotation experimental results.This work could give a deeper understanding of how sphalerite flotation behaviors are affected by iron content.
文摘In this study,the effect of decarburization annealing temperature and time on the carbon content,microstructure,and texture of grain-oriented pure iron was investigated by optical microscopy and scanning electron microscopy with electron-backscatter diffraction. The results showed that the efficiency of decarburization dramatically increased with increasing decarburization temperature. However,when the annealing temperature was increased to 825°C and 850°C,the steel's carbon content remained essentially unchanged at 0.002%. With increasing decarburization time,the steel's carbon content generally decreased. When both the decarburization temperature and time were increased further,the average grain size dramatically increased and the number of fine grains decreased; meanwhile,some relatively larger grains developed. The main texture types of the decarburized sheets were approximately the same: {001}<110> and {112~115}<110>,with a γ-fiber texture. Furthermore,little change was observed in the texture. Compared with the experimental sheets,the texture of the cold-rolled sheet was very scattered. The best average magnetic induction(B_(800)) among the final products was 1.946 T.
文摘This paper studied the changing principles of carbon content in direct reduction iron (DRI) and liquid iron in the COREX melting gasifier. Under the normal working conditions of experimental equipment, liquid nitrogen was poured into the melting gasifier from its tuyere to cool down quickly. And then seven cross sections were made to study the carburization reaction and its characteristics of the solid iron and the liquid iron, and also the reaction of carbon between the slag and the metal. According to the results, the influences of the thickness of the semi-coke layer and the temperature on the carbon content of liquid iron in the COREX melting gasifier were confirmed.
文摘Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.
基金the support from the National Key Technology R&D Program of China (No. 2011BAE23B00)the National Natural Science Foundation of China (Nos. 51104016 and 51504023the fund of the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals (No. SKL-SPM- 201204)
文摘Heating-cooling combined mold(HCCM) horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuN i10 FeM n1 alloy tubes with different Fe contents. The effects of Fe content(1.08wt%–2.01wt%) on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.
文摘Copper was surfaced on the Q235 substrate by shielded metal arc welding (SMAW) and tungsten inert-gas (TIG) arc welding, the regularity of iron element in deposited metal was analyzed by metallograph, scanning electron microscopy and energy disperse spectroscopy. The results indicate that with the increase of SMA W welding speed, the iron content decreases and the granular or spherical iron becomes more bulky in the overlay. The iron content obviously decreases with the increase of surfacing layers' numbers in multilayer welding because of the substrate dilution. On the third layer, the microstrueture of deposited metal is single-phase e-copper. Under the influence of welding methods, the granular or spherical crystal morphology is more likely to form in SMAW for the more divergent arc heat, but is dendrite in TIG welding because of centralized arc energy.
基金Project(2005CB623702)supported by the National Basic Research Program of China
文摘A great amount of red mud generated from alumina production by Bayer process not only threatens the environment but also causes waste of secondary resources.High-iron-content red mud from Bayer process was employed to recover alumina and ferric oxide by the process of reduction-sintering,leaching and then magnetic beneficiation.Results of thermodynamic analyses show that ferric oxide should be reduced to Fe if reduction of ferric oxide and formation of sodium aluminate and calcium silicate happen simultaneously.Experimental results indicate that alumina recovery of Bayer red mud can reach 89.71%,and Fe recovery rate and the grade of magnetite concentrate are 60.67%and 61.78%,respectively,under the optimized sintering conditions.
文摘This paper deals with an important role of silicon in producing ductile iron with quenched complex structure of bainite and martensite. The samples are cast in permanent mold and quenched in solution of sodium silicate. The result of thc experiments shows that the austenizing temperature should rise with increasing silicon content, otherwise much undissolved ferrite is present in the matrix after quenching. However the undissolvec ferrite can be decreased greatly or even eliminated by adding appropriate amount of ooron. On this condition, the amount of bainite gets increasing and the amount of residual austenite decreasing with the silicon cortent increasing. An approach has also been made to the mechanism of the effect of silicon on the transformation of bainite in ductile iron. The T.T.T. curves measured show that the increase of sllicon content causes the curve to shift to the left. This is quite different from the fact in steel.
基金the financial support from the National Natural Science Foundation of China(NSFC)(No.51274154)the State Key Laboratory of Development and Application Technology of Automotive Steels(Baosteel Group)
文摘Simultaneous thermal analysis(STA) was used to investigate the effects of silicon content on the oxidation kinetics of silicon-containing steels under an atmosphere and heating procedures similar to those used in industrial reheating furnaces for the production of hot-rolled strips. Our results show that when the heating temperature was greater than the melting point of Fe2SiO4, the oxidation rates of steels with different silicon contents were the same; the total mass gain decreased with increasing silicon content, whereas it increased with increasing oxygen content. The oxidation rates for steels with different silicon contents were constant with respect to time under isothermal conditions. In addition, the starting oxidation temperature, the intense oxidation temperature, and the finishing oxidation temperature increased with increasing silicon content; the intense oxidation temperature had no correlation with the melting of Fe2SiO4. Moreover, the silicon distributed in two forms: as Fe2SiO4 at the interface between the innermost layer of oxide scale and the iron matrix, and as particles containing silicon in grains and grain boundaries in the iron matrix.
文摘Deposition of protein and metal ions (Fe, Zn) in rice grains is a complex polygenic trait showing considerable environmental effect. To analyze the effect of nitrogen application levels and native soil properties on rice grain protein, iron (Fe) and zinc (Zn) contents, 32 rice genotypes were grown at three different locations each under 80 and 120 kg/hm2 nitrogen fertilizer applications. In treatments with nitrogen fertilizer application, the brown rice grain protein content (GPC) increased significantly (1.1% to 7.0%) under higher nitrogen fertilizer application (120 kg/hm2) whereas grain Fe/Zn contents showed non-significant effect of nitrogen application level, thus suggesting that the rate of uptake and translocation of macro-elements does not influence the uptake and translocation of micro-elements. The pH, organic matter content and inherent Fe/Zn levels of native soil showed significant effects on grain Fe and Zn contents of all the rice genotypes. Grain Zn content of almost all the tested rice genotypes was found to increase at Location III having loamy soil texture, neutral pH value (pH 6.83) and higher organic matter content than the other two locations (Locations I and II), indicating significant influence of native soil properties on brown rice grain Zn content while grain Fe content showed significant genotype × environment interaction effect. Genotypic difference was found to be the most significant factor to affect grain Fe/Zn contents in all the tested rice genotypes, indicating that although native soil properties influence phyto-availability of micronutrients and consequently influencing absorption, translocation and grain deposition of Fe/Zn ions, yet genetic makeup of a plant determines its response to varied soil conditions and other external factors. Two indica rice genotypes R-RF-31 (27.62 μg/g grain Zn content and 7.80% GPC) and R1033-968-2-1 (30.05 μg/g grain Zn content and 8.47% GPC) were identified as high grain Zn and moderate GPC rice genotypes. These results indicate that soil property and organic matter content increase the availability of Fe and Zn in rhizosphere, which in turn enhances the uptake, translocation and redistribution of Fe/Zn into rice grains.
文摘As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China' s current blast furnace method of producing pig low Ni iron with laterite, this study analyzed the technical characteristics and relevant problems of this process based on the discussion on the characteristics of laterite. The study aims to provide a reference for the better use of laterite in China.
基金Supported by Grants from the Universidade Federal do Pampa,Universidade Federal do Rio Grande do Sul,Universidade Federal de Santa Maria,Fundao de Amparo a Pesquisa do Estado do Rio Grande do Sul(FAPERGS)-FAPERGS/PRONEX,and FAPERGS/PRONEM,Coordenao de Aperfeioamento de Pessoal de Nível Superior,Conselho Nacional de Desenvolvimento Científico e Tecnológico,Financiadora de Estudos e Projetos
文摘AIM: To determine the plasmatic iron content and evaluate the oxidative stress(OS) markers in subjects receiving blood therapy.METHODS: Thirty-nine individuals with unspecified anemia receiving blood transfusions and 15 healthy subjects were included in the study. Anemic subjects were divided into three subgrou P:(1) those that received up to five blood transfusions(n = 14);(2) those that received from five to ten transfusions(n = 11); and(3) those that received more than ten transfusions(n = 14). Blood samples were collected by venous arm puncture and stored in tubes containing heparin. The plasma and cells were separated by centrifugation and subsequently used for analyses. Statistical analyses were performed using Kruskal-Wallis analysis of variance followed by Dunn's multiple comparison tests when appropriate.RESULTS: The eletrophoretic hemoglobin profiles of the subjects included in this study indicated that no patients presented with hemoglobinopathy. Labile plasmatic iron, ferritin, protein carbonyl, thiobarbituric acidreactive substances(TBARS) and dichlorofluorescein diacetate oxidation were significantly higher(P < 0.05), whereas total thiol levels were significantly lower(P < 0.05) in transfused subjects compared to controls. Additionally, the activity of catalase, superoxide dismutase and glutathione peroxidase were significantly lower in the transfused subjects(P < 0.05). Antioxidant enzyme activities and total thiol levels were positively correlated(P < 0.05), and negatively correlated with the levels of protein carbonyl and TBARS(P < 0.05). In contrast, protein carbonyl and TBARS were positively correlated(P < 0.05). Altogether, these data confirm the involvement of OS in patients following therapy with repeated blood transfusions.CONCLUSION: Our data reveal that changes in OS markers are correlated with levels of labile plasmatic iron and ferritin and the number of transfusions.