Reaction behaviors of sulfur and iron compounds in sodium aluminate solutions were investigated. The results show that iron compounds can remarkably remove the S2 but cannot get rid of S2Oc2-, SO^2- and SO4^-2 in sodi...Reaction behaviors of sulfur and iron compounds in sodium aluminate solutions were investigated. The results show that iron compounds can remarkably remove the S2 but cannot get rid of S2Oc2-, SO^2- and SO4^-2 in sodium aluminate solutions. The removal efficiency of S^2- using ferrous compound and ferric compound can reach 86.10% and 92.70% respectively when the iron compounds were added with a molar ratio of 2：1 compared with the sulfur in liquors at 100℃. Moreover, several same compounds are formed in those two desulfurization processes with ferrous or ferric compounds, including erdite, hematite, amorphous ferrous sulfide, polymerized sulfur-iron compounds and ferric sulfate. The major difference between these two processes is that the erdite generated from ferrous compounds at the initial reaction stage will convert to a sodium-free product FeS2 at the subsequent stage.展开更多
Selective hydrogenation of substituted nitroarenes is an important reaction to obtain amines.Supported metal catalysts are wildly used in this reaction because the surface structure of supports can tune the properties...Selective hydrogenation of substituted nitroarenes is an important reaction to obtain amines.Supported metal catalysts are wildly used in this reaction because the surface structure of supports can tune the properties of the supported metal nanoparticles(NPs)and promote the selectivity to amines.Herein,Pt NPs were immobilized on Fe OOH,Fe_(3)O_(4)andα-Fe_2O_(3)nanorods to synthesize a series of iron compounds supported Pt catalysts by liquid phase reduction method.Chemoselective hydrogenation of 3-nitrostyrene to 3-aminostyrene was used as probe reaction to evaluate the performance of the catalysts.The results show that Pt/Fe OOH exhibits the highest selectivity and activity.Fe OOH support with pores and-OH groups can tune the electronic structure of Pt NPs.The positive charge of Pt NPs supported on Fe OOH is key factor for improving the catalytic performance.展开更多
The utilization of highly reactive and high-strength coke can enhance the efficiency of blast furnace by promoting indirect reduction of iron oxides.Iron compounds,as the main constituent in iron-bearing minerals,have...The utilization of highly reactive and high-strength coke can enhance the efficiency of blast furnace by promoting indirect reduction of iron oxides.Iron compounds,as the main constituent in iron-bearing minerals,have aroused wide interest in preparation of highly reactive iron coke.However,the effects of iron compounds on pyrolysis behavior of coal and metallurgical properties of resultant cokes are still unclear.Thus,three iron compounds,i.e.,Fe;O;,Fe;O;and FeC;O;·2H;O,were adopted to investigate their effects on coal pyrolysis behavior and metallurgical properties of the resultant cokes.The results show that iron compounds have slight effects on the thermal behavior of coal blend originated from thermogravimetric and differential thermogravimetric curves.The apparent activation energy varies with different iron compounds ranging from 94.85 to 110.11 kJ/mol in the primary pyrolysis process,while lower apparent activation energy is required for the secondary pyrolysis process.Iron compounds have an adverse influence on the mechanical properties and carbon structure of cokes.Strong correlations exist among coke reactivity,coke strength after reaction,and the content of metallic iron in cokes or the values of crystallite stacking height,which reflect the dependency of thermal property on metallic iron content and carbon structure of cokes.展开更多
The centrifugal casting of compound HSS/nodular cast iron roll collar was studied,and the factors affecting transition zone quality were analyzed.The pouring temperature and interval in pouring are the main factors af...The centrifugal casting of compound HSS/nodular cast iron roll collar was studied,and the factors affecting transition zone quality were analyzed.The pouring temperature and interval in pouring are the main factors affecting transition zone quality.By controlling process parameter and flux adding during casting,high quality roll collar was obtained.The cause,why in the casting of HSS part,segregation appears easily,was analyzed and the countermeasure eliminating segregation was put forward,the measure eliminating heat treatment crackling was also put forward.展开更多
The disconnection between teaching,learning,and evaluation is particularly pronounced in traditional high school chemistry teaching.To align with the demands of the new curriculum standards for talent development,it i...The disconnection between teaching,learning,and evaluation is particularly pronounced in traditional high school chemistry teaching.To align with the demands of the new curriculum standards for talent development,it is essential to implement reforms and innovations in teaching methods.This paper initially elucidates the integrated concept of teaching,learning,and evaluation,as well as its practical significance in the classroom.Subsequently,it explores the effective teaching design centered on the theme of iron and its compounds,actively investigating the implementation approach of the integration principle of teaching,learning,and evaluation in classroom.Furthermore,the paper emphasizes the pivotal role of the evaluation part in fostering the professional development of teachers and enhancing the core competencies of students,ultimately aiming to achieve high efficiency and quality in chemistry classroom teaching.展开更多
The distribution and form of iron and calcium compounds were studied using hydrogenation feedstock and hydrogenation products with different space velocities as the research object.The content of metallic elements,suc...The distribution and form of iron and calcium compounds were studied using hydrogenation feedstock and hydrogenation products with different space velocities as the research object.The content of metallic elements,such as calcium and iron in hydrogenation feedstock,and extract samples were determined via flame atomic absorption spectrometry.The water-soluble iron and calcium species in oil samples were determined by an IC2010 high-throughput ion chromatograph.Nearly 60%-80%of the iron or calcium compounds were mainly concentrated in resins and asphaltenes.Iron and calcium compounds mainly exist in the form of oil-soluble metal species in hydrogenation feedstock and hydrogenation products.Under certain conditions of reaction temperature,pressure,and volume ratio of hydrogen to oil,when the reaction space velocity was 0.6 h^(−1),about 30%of the iron or calcium compounds were converted from oil-soluble to water-soluble species after hydrogenation.When the reaction space velocity was decreased from 1.70 to 0.60 h^(−1),the proportion of iron compounds converted from oil-soluble to water-soluble increased from 8.4%to 28%.Moreover,the proportion of calcium compounds converted from oil-soluble to water-soluble increased from 10%to 37%.This denotes that with decreasing reaction space velocity,the ratio of oil-soluble to water-soluble species increases.Water-soluble iron and calcium compounds are present in the form of inorganic salts,such as chlorate and sulfate.This study helps in understanding the removal mechanism of iron and calcium compounds and optimizing the operating conditions of residue hydrogenation.展开更多
This study was conducted to determine the content,distribution and transformation of iron oxides in the soils of the Middle Euphrates regions in Iraq.The study included four sites:Tuwairij area in Karbala Governorate,...This study was conducted to determine the content,distribution and transformation of iron oxides in the soils of the Middle Euphrates regions in Iraq.The study included four sites:Tuwairij area in Karbala Governorate,College of Agriculture at the University of Kufa in Najaf Governorate,College of Agriculture at the University of Qadisiyah in Diwaniyah Governorate,and the Nile District in Babylon Governorate.The results showed that the soils of Najaf and Qadisiyah were superior in terms of their content of total free iron oxides(Fet)compared to the soils of Karbala and Babylon.The relative distribution of free iron oxides was generally close among the studied sites,with a homogeneous pattern in the distribution of these oxides within the soil horizons.As for silicate iron oxides(Fes),a homogeneous pattern was observed in the soil of Babylon with its content increasing with depth,while these patterns varied in the soils of Karbala,Najaf and Qadisiyah.Regarding the ratios of crystalline iron oxides(Fed/Fet),the study showed that the Babylon and Qadisiyah soils recorded the highest values,while these values were lower in the Najaf and Karbala soils.On the other hand,amorphous iron oxides(FeO)showed similar values in the Najaf and Qadisiyah soils.In general,these results clearly showed the effect of environmental and geochemical factors of the study areas on the distribution and transformations of iron oxides in the soil of the Middle Euphrates regions.展开更多
Forty-six candidate phenol/benzoate degrading-iron reducing bacteria were isolated from long term irrigated tropical paddy soils by enrichment procedures.Pure cultures and some prepared mixed cultures were examined fo...Forty-six candidate phenol/benzoate degrading-iron reducing bacteria were isolated from long term irrigated tropical paddy soils by enrichment procedures.Pure cultures and some prepared mixed cultures were examined for ferric oxide reduction and phenol/benzoate degradation.All the isolates were iron reducers,but only 56.5%could couple iron reduction to phenol and/or benzoate degradation,as evidenced by depletion of phenol and benzoate after one week incubation.Analysis of degradative capability using Biolog...展开更多
The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (F...The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved to enhance the bioavailable iron to phytoplankton by keeping minimal sulfur compounds in HNLC regions. The low productivity of phytoplankton by grazing control in HNLC regions was 6% diatoms whose 52% was grazed by copepods and 42% by krill on the basis of data analysis in 2000 EisenEx Experiment at boundary of Antarctic and African tectonic plates. All of the previous iron fertilization experiments were conducted at volcanic sulfur compounds enriched HNLC regions. The present study revealed that the enhanced phytoplankton productivity in batch culture without sedimentary iron sulfides can be possible only if sulfur compounds are minimal, as is in Shag Rocks (53°S, 42°W) of South Georgia in Scotia Sea in the Southern Ocean.展开更多
Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was w...Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was worth noting that the catalyst exhibited extremely high activity. The reduction could be completed within 20-50 min and the yields were up to 97-99 %.展开更多
Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ...Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.展开更多
Iron overload is closely related to many diseases. Iron overload is a risk factor that triggers a series of health problems. The toxicity of iron is that iron can catalyze the formation of oxygen free radicals and can...Iron overload is closely related to many diseases. Iron overload is a risk factor that triggers a series of health problems. The toxicity of iron is that iron can catalyze the formation of oxygen free radicals and can be used as a nutrient necessary for the growth of microorganisms and tumor cells. The sensitivity of human cells to iron toxicity varies widely. Causes of iron overload include genetic factors, behavioral factors and environmental factors. With the rapid development of modem industry, iron and its compound dust distribution industry and the increasingly widespread, in the iron pigment production, mechanical casting, iron ore mining and iron smelting operations will produce a lot of iron and its compound dust, Its impact on the human body has been of concern. Long-term exposure to iron and its compounds can cause different degrees of damage to the respiratory system, resulting in iron in vivo disorder. The relationship between iron metabolism and lung injury has also begun to be concerned, and maintaining iron homeostasis is important for lung injury and its protection.展开更多
A series of both unsupported and coal‐supported iron–oxygen compounds with gradual changes in microstructure were synthesized by a precipitation‐oxidation process at 20 to 70°C.The relationship between the mic...A series of both unsupported and coal‐supported iron–oxygen compounds with gradual changes in microstructure were synthesized by a precipitation‐oxidation process at 20 to 70°C.The relationship between the microstructures and catalytic activities of these precursors during direct coal liquefaction was studied.The results show that the microstructure could be controlled through adjusting the synthesis temperature during the precipitation‐oxidation procedure,and that compounds synthesized at lower temperatures exhibit higher catalytic activity.As a result of their higher proportions ofγ‐FeOOH orα‐FeOOH crystalline phases,the unsupported iron–oxygen compounds synthesized at 20–30°C,which also had high specific surface areas and moisture levels,generate oil yields 4.5%–4.6%higher than those obtained with precursors synthesized at 70°C.It was also determined that higher oil yields were obtained when the catalytically‐active phase formed by the precursors during liquefaction(pyrrhotite,Fe1-xS)had smaller crystallites.Feed coal added as a carrier was found to efficiently disperse the active precursors,which in turn significantly improved the catalytic activity during coal liquefaction.展开更多
Gray cast irons were inoculated with FeSi75＋RE and FeSi75＋Sr inoculants. The changes of apex angle of the drills before and after being used were used to evaluate machinability of gray cast irons. Effect of FeSi75＋...Gray cast irons were inoculated with FeSi75＋RE and FeSi75＋Sr inoculants. The changes of apex angle of the drills before and after being used were used to evaluate machinability of gray cast irons. Effect of FeSi75＋RE and FeSi75＋Sr inoculants on mechanical properties, machinability and sensibility of gray cast iron used in cylinder block were investigated. Experimental results showed that gray cast iron treated with 60%FeSi75＋40% RE inoculants exhibited tensile strength consistently at about 295 MPa along with good hardness and improved metallurgical quality. While gray cast iron inoculated with 20%FeSi75＋80% Sr inoculants exhibited the best machinability, the lowest cross-section sensibility and the least microhardness difference. The tool flank wear of the drill increased correspondingly with the increase of the microhardness difference of the matrix, indicating the great effect of homogeneity of the matrix on the machinability of gray cast iron.展开更多
Effect of several complex inoculants on mechanical properties, process-ability and sensibility of grey cast iron used in cylinder block were investigated. The experimental results showed that the grey cast iron treate...Effect of several complex inoculants on mechanical properties, process-ability and sensibility of grey cast iron used in cylinder block were investigated. The experimental results showed that the grey cast iron treated with 60%FeSi75+40%RE complex inoculants has tensile strength consistently at about 295 MPa along with good hardness and improved metallurgy quality. While the grey cast iron inoculated with 20%FeSi75+80%Sr compound inoculants has the best process-ability, the lowest cross-section sensibility and the least microhardness difference. The wear amount of the drill increases correspondingly with the increase of the microhardness difference of matrix structure, indicating the great effect of homogeneousness of matrix structure in the grey cast iron on the machinability of the grey cast iron.展开更多
Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reducti...Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.展开更多
Hereditary hemochromatosis is a condition characterized by iron overload, which is both treatable and preventable. It’s mainly related to hepcidin deficiency related to mutations in genes involved in hepcidin regulat...Hereditary hemochromatosis is a condition characterized by iron overload, which is both treatable and preventable. It’s mainly related to hepcidin deficiency related to mutations in genes involved in hepcidin regulation. Iron overload increases the risk of disease such as liver cirrhosis, heart disease and diabetes. Two HFE genotypes have been commonly described in cases of iron overload, C282Y homozygosity and C282Y/H63D compound heterozygoty. The diagnosis of this rare disease now can be explored by biological and imaging tools. We report a case of compound heterozygous C282Y/H63D discovered by family screening for elevated serum ferritin.展开更多
The intercalatants presence of Fe-KCl graphite intercalation compound (Fe-KCl G/C) is in the form of independent crystalline phase. In this paper, its distribution in the carbon interlayer, crystalline status and powd...The intercalatants presence of Fe-KCl graphite intercalation compound (Fe-KCl G/C) is in the form of independent crystalline phase. In this paper, its distribution in the carbon interlayer, crystalline status and powder sizes have been studied by X-ray diffraction (XRD) , small angle X-ray scattering (SAXS) and transmission electron microscope (TEM). And the partial crystal structure of the GIC has been researched too.展开更多
The graphite encapsulated a-Fe particles were prepared by reduction of stage-2 and stage-3 FeCI3 graphite intercalation compounds （GICs） with metallic potassium, X-ray diffraction analysis （XRD）, energy dispersive...The graphite encapsulated a-Fe particles were prepared by reduction of stage-2 and stage-3 FeCI3 graphite intercalation compounds （GICs） with metallic potassium, X-ray diffraction analysis （XRD）, energy dispersive X-ray spectroscopy （EDS） investigation and transmission electron microscopy （TEM） observation show that the reduction products of stage-2 FeCl3-GICs contains more abundant a-Fe nanoparticles than those of stage-3. High-resolution TEM （HRTEM） observation reveals that the nanoparticle of a-Fe was polycrystals or twins, which was real or quasi two-dimension in shape, and whose space orientation was strictly controlled by the graphene. Based on the experiment results, a possible growth model of the graphite encapsulated ct-Fe was proposed.展开更多
基金Project(51374239)supported by the National Natural Science Foundation of China
文摘Reaction behaviors of sulfur and iron compounds in sodium aluminate solutions were investigated. The results show that iron compounds can remarkably remove the S2 but cannot get rid of S2Oc2-, SO^2- and SO4^-2 in sodium aluminate solutions. The removal efficiency of S^2- using ferrous compound and ferric compound can reach 86.10% and 92.70% respectively when the iron compounds were added with a molar ratio of 2：1 compared with the sulfur in liquors at 100℃. Moreover, several same compounds are formed in those two desulfurization processes with ferrous or ferric compounds, including erdite, hematite, amorphous ferrous sulfide, polymerized sulfur-iron compounds and ferric sulfate. The major difference between these two processes is that the erdite generated from ferrous compounds at the initial reaction stage will convert to a sodium-free product FeS2 at the subsequent stage.
基金the financial support provided by the National Natural Science Foundation of China(Nos.22072164,21773269,51932005 and 21761132025)the Liao Ning Revitalization Talents Program(No.XLYC1807175)。
文摘Selective hydrogenation of substituted nitroarenes is an important reaction to obtain amines.Supported metal catalysts are wildly used in this reaction because the surface structure of supports can tune the properties of the supported metal nanoparticles(NPs)and promote the selectivity to amines.Herein,Pt NPs were immobilized on Fe OOH,Fe_(3)O_(4)andα-Fe_2O_(3)nanorods to synthesize a series of iron compounds supported Pt catalysts by liquid phase reduction method.Chemoselective hydrogenation of 3-nitrostyrene to 3-aminostyrene was used as probe reaction to evaluate the performance of the catalysts.The results show that Pt/Fe OOH exhibits the highest selectivity and activity.Fe OOH support with pores and-OH groups can tune the electronic structure of Pt NPs.The positive charge of Pt NPs supported on Fe OOH is key factor for improving the catalytic performance.
基金supported by the National Natural Science Foundation of China(Grant No.51474042)
文摘The utilization of highly reactive and high-strength coke can enhance the efficiency of blast furnace by promoting indirect reduction of iron oxides.Iron compounds,as the main constituent in iron-bearing minerals,have aroused wide interest in preparation of highly reactive iron coke.However,the effects of iron compounds on pyrolysis behavior of coal and metallurgical properties of resultant cokes are still unclear.Thus,three iron compounds,i.e.,Fe;O;,Fe;O;and FeC;O;·2H;O,were adopted to investigate their effects on coal pyrolysis behavior and metallurgical properties of the resultant cokes.The results show that iron compounds have slight effects on the thermal behavior of coal blend originated from thermogravimetric and differential thermogravimetric curves.The apparent activation energy varies with different iron compounds ranging from 94.85 to 110.11 kJ/mol in the primary pyrolysis process,while lower apparent activation energy is required for the secondary pyrolysis process.Iron compounds have an adverse influence on the mechanical properties and carbon structure of cokes.Strong correlations exist among coke reactivity,coke strength after reaction,and the content of metallic iron in cokes or the values of crystallite stacking height,which reflect the dependency of thermal property on metallic iron content and carbon structure of cokes.
文摘The centrifugal casting of compound HSS/nodular cast iron roll collar was studied,and the factors affecting transition zone quality were analyzed.The pouring temperature and interval in pouring are the main factors affecting transition zone quality.By controlling process parameter and flux adding during casting,high quality roll collar was obtained.The cause,why in the casting of HSS part,segregation appears easily,was analyzed and the countermeasure eliminating segregation was put forward,the measure eliminating heat treatment crackling was also put forward.
文摘The disconnection between teaching,learning,and evaluation is particularly pronounced in traditional high school chemistry teaching.To align with the demands of the new curriculum standards for talent development,it is essential to implement reforms and innovations in teaching methods.This paper initially elucidates the integrated concept of teaching,learning,and evaluation,as well as its practical significance in the classroom.Subsequently,it explores the effective teaching design centered on the theme of iron and its compounds,actively investigating the implementation approach of the integration principle of teaching,learning,and evaluation in classroom.Furthermore,the paper emphasizes the pivotal role of the evaluation part in fostering the professional development of teachers and enhancing the core competencies of students,ultimately aiming to achieve high efficiency and quality in chemistry classroom teaching.
基金supported by the National Natural Science Foundation of China (No. 21576292)the independent innovation research project of China University of Petroleum (East China) (No. 22CX0300A)
文摘The distribution and form of iron and calcium compounds were studied using hydrogenation feedstock and hydrogenation products with different space velocities as the research object.The content of metallic elements,such as calcium and iron in hydrogenation feedstock,and extract samples were determined via flame atomic absorption spectrometry.The water-soluble iron and calcium species in oil samples were determined by an IC2010 high-throughput ion chromatograph.Nearly 60%-80%of the iron or calcium compounds were mainly concentrated in resins and asphaltenes.Iron and calcium compounds mainly exist in the form of oil-soluble metal species in hydrogenation feedstock and hydrogenation products.Under certain conditions of reaction temperature,pressure,and volume ratio of hydrogen to oil,when the reaction space velocity was 0.6 h^(−1),about 30%of the iron or calcium compounds were converted from oil-soluble to water-soluble species after hydrogenation.When the reaction space velocity was decreased from 1.70 to 0.60 h^(−1),the proportion of iron compounds converted from oil-soluble to water-soluble increased from 8.4%to 28%.Moreover,the proportion of calcium compounds converted from oil-soluble to water-soluble increased from 10%to 37%.This denotes that with decreasing reaction space velocity,the ratio of oil-soluble to water-soluble species increases.Water-soluble iron and calcium compounds are present in the form of inorganic salts,such as chlorate and sulfate.This study helps in understanding the removal mechanism of iron and calcium compounds and optimizing the operating conditions of residue hydrogenation.
文摘This study was conducted to determine the content,distribution and transformation of iron oxides in the soils of the Middle Euphrates regions in Iraq.The study included four sites:Tuwairij area in Karbala Governorate,College of Agriculture at the University of Kufa in Najaf Governorate,College of Agriculture at the University of Qadisiyah in Diwaniyah Governorate,and the Nile District in Babylon Governorate.The results showed that the soils of Najaf and Qadisiyah were superior in terms of their content of total free iron oxides(Fet)compared to the soils of Karbala and Babylon.The relative distribution of free iron oxides was generally close among the studied sites,with a homogeneous pattern in the distribution of these oxides within the soil horizons.As for silicate iron oxides(Fes),a homogeneous pattern was observed in the soil of Babylon with its content increasing with depth,while these patterns varied in the soils of Karbala,Najaf and Qadisiyah.Regarding the ratios of crystalline iron oxides(Fed/Fet),the study showed that the Babylon and Qadisiyah soils recorded the highest values,while these values were lower in the Najaf and Karbala soils.On the other hand,amorphous iron oxides(FeO)showed similar values in the Najaf and Qadisiyah soils.In general,these results clearly showed the effect of environmental and geochemical factors of the study areas on the distribution and transformations of iron oxides in the soil of the Middle Euphrates regions.
文摘Forty-six candidate phenol/benzoate degrading-iron reducing bacteria were isolated from long term irrigated tropical paddy soils by enrichment procedures.Pure cultures and some prepared mixed cultures were examined for ferric oxide reduction and phenol/benzoate degradation.All the isolates were iron reducers,but only 56.5%could couple iron reduction to phenol and/or benzoate degradation,as evidenced by depletion of phenol and benzoate after one week incubation.Analysis of degradative capability using Biolog...
文摘The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved to enhance the bioavailable iron to phytoplankton by keeping minimal sulfur compounds in HNLC regions. The low productivity of phytoplankton by grazing control in HNLC regions was 6% diatoms whose 52% was grazed by copepods and 42% by krill on the basis of data analysis in 2000 EisenEx Experiment at boundary of Antarctic and African tectonic plates. All of the previous iron fertilization experiments were conducted at volcanic sulfur compounds enriched HNLC regions. The present study revealed that the enhanced phytoplankton productivity in batch culture without sedimentary iron sulfides can be possible only if sulfur compounds are minimal, as is in Shag Rocks (53°S, 42°W) of South Georgia in Scotia Sea in the Southern Ocean.
文摘Sulphur-containing aromatic nitro compounds were rapidly reduced to the corresponding amines in high yields by employing hydrazine hydrate as a hydrogen donor in the presence of iron oxide hydroxide catalyst. It was worth noting that the catalyst exhibited extremely high activity. The reduction could be completed within 20-50 min and the yields were up to 97-99 %.
文摘Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.
文摘Iron overload is closely related to many diseases. Iron overload is a risk factor that triggers a series of health problems. The toxicity of iron is that iron can catalyze the formation of oxygen free radicals and can be used as a nutrient necessary for the growth of microorganisms and tumor cells. The sensitivity of human cells to iron toxicity varies widely. Causes of iron overload include genetic factors, behavioral factors and environmental factors. With the rapid development of modem industry, iron and its compound dust distribution industry and the increasingly widespread, in the iron pigment production, mechanical casting, iron ore mining and iron smelting operations will produce a lot of iron and its compound dust, Its impact on the human body has been of concern. Long-term exposure to iron and its compounds can cause different degrees of damage to the respiratory system, resulting in iron in vivo disorder. The relationship between iron metabolism and lung injury has also begun to be concerned, and maintaining iron homeostasis is important for lung injury and its protection.
文摘A series of both unsupported and coal‐supported iron–oxygen compounds with gradual changes in microstructure were synthesized by a precipitation‐oxidation process at 20 to 70°C.The relationship between the microstructures and catalytic activities of these precursors during direct coal liquefaction was studied.The results show that the microstructure could be controlled through adjusting the synthesis temperature during the precipitation‐oxidation procedure,and that compounds synthesized at lower temperatures exhibit higher catalytic activity.As a result of their higher proportions ofγ‐FeOOH orα‐FeOOH crystalline phases,the unsupported iron–oxygen compounds synthesized at 20–30°C,which also had high specific surface areas and moisture levels,generate oil yields 4.5%–4.6%higher than those obtained with precursors synthesized at 70°C.It was also determined that higher oil yields were obtained when the catalytically‐active phase formed by the precursors during liquefaction(pyrrhotite,Fe1-xS)had smaller crystallites.Feed coal added as a carrier was found to efficiently disperse the active precursors,which in turn significantly improved the catalytic activity during coal liquefaction.
基金supported by Program for Scientific and Technological Renovation Talents in University of Henan Province (2009HASTIT023)the National Natural Science Foundation of China (50771042)
文摘Gray cast irons were inoculated with FeSi75＋RE and FeSi75＋Sr inoculants. The changes of apex angle of the drills before and after being used were used to evaluate machinability of gray cast irons. Effect of FeSi75＋RE and FeSi75＋Sr inoculants on mechanical properties, machinability and sensibility of gray cast iron used in cylinder block were investigated. Experimental results showed that gray cast iron treated with 60%FeSi75＋40% RE inoculants exhibited tensile strength consistently at about 295 MPa along with good hardness and improved metallurgical quality. While gray cast iron inoculated with 20%FeSi75＋80% Sr inoculants exhibited the best machinability, the lowest cross-section sensibility and the least microhardness difference. The tool flank wear of the drill increased correspondingly with the increase of the microhardness difference of the matrix, indicating the great effect of homogeneity of the matrix on the machinability of gray cast iron.
基金The paper is supported by the key Science and Technology Project of Henan Province(0424290064) the fund items of Henan Province Natural Science( 0411050100).
文摘Effect of several complex inoculants on mechanical properties, process-ability and sensibility of grey cast iron used in cylinder block were investigated. The experimental results showed that the grey cast iron treated with 60%FeSi75+40%RE complex inoculants has tensile strength consistently at about 295 MPa along with good hardness and improved metallurgy quality. While the grey cast iron inoculated with 20%FeSi75+80%Sr compound inoculants has the best process-ability, the lowest cross-section sensibility and the least microhardness difference. The wear amount of the drill increases correspondingly with the increase of the microhardness difference of matrix structure, indicating the great effect of homogeneousness of matrix structure in the grey cast iron on the machinability of the grey cast iron.
基金financially supported by the National Natural Science Foundation of China(No.51674018)
文摘Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.
文摘Hereditary hemochromatosis is a condition characterized by iron overload, which is both treatable and preventable. It’s mainly related to hepcidin deficiency related to mutations in genes involved in hepcidin regulation. Iron overload increases the risk of disease such as liver cirrhosis, heart disease and diabetes. Two HFE genotypes have been commonly described in cases of iron overload, C282Y homozygosity and C282Y/H63D compound heterozygoty. The diagnosis of this rare disease now can be explored by biological and imaging tools. We report a case of compound heterozygous C282Y/H63D discovered by family screening for elevated serum ferritin.
文摘The intercalatants presence of Fe-KCl graphite intercalation compound (Fe-KCl G/C) is in the form of independent crystalline phase. In this paper, its distribution in the carbon interlayer, crystalline status and powder sizes have been studied by X-ray diffraction (XRD) , small angle X-ray scattering (SAXS) and transmission electron microscope (TEM). And the partial crystal structure of the GIC has been researched too.
基金financially supported by the National Basic Research Program of China(Nos.2013CB632601 and 2013CB632604)the National Science Foundation for Distinguished Young Scholars of China(Nos.51125018 and 51504230)+2 种基金the Key Research Program of Chinese Academy of Sciences(No.KGZD-EW-201-2)the National Natural Science Foundation of China(Nos.51374191 and 2110616751104139)China Postdoctoral Science Foundation(Nos.2012M510552 and 2013T60175)
基金the Natural Science Foundation of Hubei Province (No.2004ABA090)the Fund from the Chengguang Plan of Wuhan(No.20065004116-35)
文摘The graphite encapsulated a-Fe particles were prepared by reduction of stage-2 and stage-3 FeCI3 graphite intercalation compounds （GICs） with metallic potassium, X-ray diffraction analysis （XRD）, energy dispersive X-ray spectroscopy （EDS） investigation and transmission electron microscopy （TEM） observation show that the reduction products of stage-2 FeCl3-GICs contains more abundant a-Fe nanoparticles than those of stage-3. High-resolution TEM （HRTEM） observation reveals that the nanoparticle of a-Fe was polycrystals or twins, which was real or quasi two-dimension in shape, and whose space orientation was strictly controlled by the graphene. Based on the experiment results, a possible growth model of the graphite encapsulated ct-Fe was proposed.
