Novel coal gangue-based persulfate catalyst(CG-FeCl_(2))was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate(FeCl_(2)·_(4)H_(2)O).T...Novel coal gangue-based persulfate catalyst(CG-FeCl_(2))was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate(FeCl_(2)·_(4)H_(2)O).The phase transformation of the prepared materials and gas products during the heating process are thoroughly investigated.It is suggested that ferrous chloride participated in the phase transformation and formed Si-O-Fe bonds.And the main gaseous products are H_(2)O,H_(2),and HCl during the heating process.Besides,the ability of CG-FeCl_(2) to activate peroxymonosulfate(PMS)for catalytic degradation of polycyclic aromatic hydrocarbons(PAHs)and phenol was deeply studied.More than 95%of naphthyl,phenanthrene and phenol were removed under optimizied conditions.In addition,1O_(2),·OH,and SO_(4)·−were involved in the CG-FeCl_(2)/PMS system from the free radical scavenging experiment,where 1O_(2) played a major role during the oxidation process.Furthermore,CG-FeCl_(2)/PMS system exhibited superior stability in a relatively wide pH range and the presence of common anion from related degradation experiments.Overall,the novel CG-FeCl_(2) is an efficient and environmentally friendly catalyst,displaying potential application prospect in the field of PAHs and phenol-contaminated wastewater treatment.展开更多
A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China wer...A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.展开更多
To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malon...To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malonaldelyde (MDA) were determined. The root oxidizing ability and yield characters of rice were examined. Results showed that appropriate amount of Se enhanced the activity of glutathione peroxidase and the oxidizing ability of rice roots significantly, reduced the concentration of MDA, increased 1000-grain weight of rice, F = 26.96**, decreased empty and blighted grain rate, increased the rice yield, F = 11.53**, and enhanced the rice resistance under ferrous stress.展开更多
The effect of hydraulic retention time (HRT) and pH on the biooxidation of ferrous iron during simulated acid mine drainage (AMD) treatment was investigated.The simulated AMD was highly acidic (pH 2.5), rich in iron (...The effect of hydraulic retention time (HRT) and pH on the biooxidation of ferrous iron during simulated acid mine drainage (AMD) treatment was investigated.The simulated AMD was highly acidic (pH 2.5), rich in iron (about 1700 mg/L) and copper (about 200 mg/L), and contained high concentrations of sulfate (about 4700 mg/L).The biooxidation of ferrous iron was studied in a laboratory-scale upflow packed bed bioreactor (PBR).The HRT was shortened stepwise from 40 h to 20 h, 13 h, and 8 h under the acidic environment at a pH value of 2.2.Then, the influent pH value was changed from 2.2 to 1.2 at a constant suitable HRT.Physiochemical and microbial community structure analyses were performed on water samples and stuffing collected from the bioreactor under different conditions.The results indicate that the efficiency of ferrous iron oxidation gradually decreased with the decrease of HRT, and when the HRT exceeded 13 h, ferrous iron in AMD was almost completely oxidized.In addition, the best efficiency of ferrous iron oxidation was achieved at the influent pH value of 1.8.Microbial community structure analyses show that Leptospirillum is the predominant genus attached in the bioreactor, and low influent pH values are suitable for the growth of Leptospirillum.展开更多
Diamond tools play a critical role in ultra-precision machining due to their excellent physical and mechanical material properties,such as that cutting edge can be sharpened to nanoscale accuracy.However,abrasive chem...Diamond tools play a critical role in ultra-precision machining due to their excellent physical and mechanical material properties,such as that cutting edge can be sharpened to nanoscale accuracy.However,abrasive chemical reactions between diamond and non-diamond-machinable metal elements,including Fe,Cr,Ti,Ni,etc,can cause excessive tool wear in diamond cutting of such metals and most of their alloys.This paper reviews the latest achievements in the chemical wear and wear suppression methods for diamond tools in cutting of ferrous metals.The focus will be on the wear mechanism of diamond tools,and the typical wear reduction methods for diamond cutting of ferrous metals,including ultrasonic vibration cutting,cryogenic cutting,surface nitridation and plasma assisted cutting,etc.Relevant commercially available devices are introduced as well.Furthermore,future research trends in diamond tool wear suppression are discussed and examined.展开更多
Reduction rate of ferrous oxide in smelting reduction with iron bath has been studied. The main affecting factors on reduction rate, such as composition of the melt, temperature of molten bath, basicity of slag...Reduction rate of ferrous oxide in smelting reduction with iron bath has been studied. The main affecting factors on reduction rate, such as composition of the melt, temperature of molten bath, basicity of slag and the way of supplying carbonaceous materials have also been investigated.展开更多
We numerically simulated and experimentally studied the interfacialcarbon diffusion between diamond tooland workpiece materials.A diffusion modelwith respect to carbon atoms of diamond toolpenetrating into chips and m...We numerically simulated and experimentally studied the interfacialcarbon diffusion between diamond tooland workpiece materials.A diffusion modelwith respect to carbon atoms of diamond toolpenetrating into chips and machined surface was established.The numericalsimulation results of the diffusion process revealthat the distribution laws of carbon atoms concentration have a close relationship with the diffusion distance,the diffusion time,and the originalcarbon concentration of the work material.In addition,diamond face cutting tests of die steels with different carbon content are conducted at different depth of cuts and feed rates to verify the previous simulation results.The micro-morphology of the chips is detected by scanning electron microscopy.Energy dispersive X-ray analysis was proposed to investigate the change in carbon content of the chips surface.The experimentalresults of this work are of benefit to a better understanding on the diffusion wear mechanism in single crystaldiamond cutting of ferrous metals.Moreover,the experimentalresults show that the diffusion wear of diamond could be reduced markedly by applying ultrasonic vibration to the cutting toolcompared with conventionalturning.展开更多
Objective: To compare the efficacy and compliance of the conventional therapy of iron deficiency anemia (ferrous sulfate) with the new forms of therapy chewable iron tablets: (iron polymaltose complex) in the treatmen...Objective: To compare the efficacy and compliance of the conventional therapy of iron deficiency anemia (ferrous sulfate) with the new forms of therapy chewable iron tablets: (iron polymaltose complex) in the treatment of iron deficiency anemia in pregnant women. Methods: This Randomized Control Trial study included 290 pregnant women with iron deficiency anemia, and they were randomly allocated to a control group who received ferrous sulfate capsules for two months and study group who received iron polymaltose complex chewable tablets for two months. Complete Blood Picture (hemoglobin level and hematocrit level) and Serum ferritin level were done after four and eight weeks to determine the efficacy. In addition, any complains or side effects had been reported to assess the tolerability of the drugs. Two-factor repeated-measures analysis of variance (ANOVA) was used to compare the change in hemoglobin and serum ferritin levels in both groups. Results: There was no statistical significant difference between the two research groups as regards baseline hemoglobin, and at week 4 from onset of treatment (p values = 0.990, 0.112, consecutively). However, there was statistical significant difference on week 8 of continuous drug intake in both groups in which the iron poly maltose complex research group had significantly higher hemoglobin levels (p value = 0.006). Conclusion: The results of the study showed oral iron polymaltose complex increases Hemoglobin and serum ferritin levels more than oral ferrous sulfate and produces less adverse effects than ferrous sulfate.展开更多
The reduction of less stable ferric hydroxides and formation of ferrous phases is critical for the fate of phosphorus in anaerobic soils and sediments. The interaction between ferrous iron and phosphate was investigat...The reduction of less stable ferric hydroxides and formation of ferrous phases is critical for the fate of phosphorus in anaerobic soils and sediments. The interaction between ferrous iron and phosphate was investigated experimentally during the reduction of synthetic ferrihydrite with natural organic materials as carbon source. Ferrihydrite was readily reduced by dissimilatory iron reducing bacteria (DIRB) with between 52% and 73% Fe(III) converted to Fe(II) after 31 days, higher than without DIRB. Formation of ferrous phases was linearly coupled to almost complete removal of both aqueous and exchangeable phosphate. Simple model calculations based on the incubation data suggested ferrous phases bound phosphate with a molar ratio of Fe(II):P between 1.14 - 2.25 or a capacity of 246 - 485 mg·P·g-1 Fe(II). XRD analysis indicated that the ratio of Fe(II): P was responsible for the precipitation of vivianite (Fe3(PO4)2·8H2O), a dominant Fe(II) phosphate mineral in incubation systems. When the ratio of Fe(II):P was more than 1.5, the precipitation of Fe(II) phosphate was soundly crystallized to vivianite. Thus, reduction of ferric iron provides a mechanism for the further removal of available phosphate via the production of ferrous phases, with anaerobic soils and sediments potentially exhibiting a higher capacity to bind phosphate than some aerobic systems.展开更多
The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate im...The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.展开更多
This paper discusses the toxicity and mobility of chromium species. And it presents the extent and kinetics of reductive remediation of hexavalent chromium, Cr+ using ferrous ion, Fe2+. Molar ratios of 1:3 and 1:6 of ...This paper discusses the toxicity and mobility of chromium species. And it presents the extent and kinetics of reductive remediation of hexavalent chromium, Cr+ using ferrous ion, Fe2+. Molar ratios of 1:3 and 1:6 of Cr (VI) to Fe (II) were used. Integral method of data analysis showed reaction followed second-order kinetics with R square values near unity. Reaction was initially fast but with a rapid precipitation attributed to Cr (III)-Fe (III) in previous studies. This colloidal precipitate ultimately stops the reaction, which explains while conversion efficiency increases with increased molar ratio of Cr (VI) to Fe (II). The impact of pH was investigated by adjusting the Cr (VI)-Fe (II) medium to pH 2.78, 5.24, 7.00, 9.00 and 11.96 using predetermined drops of acid or base. Reaction was more rapid under alkaline conditions with higher extent of degradation consistent with previous research. In soil system, mass transfer limitation was hardly noticed as high extent of reduction was recorded relative to aqueous phase. The high solubility of Cr (VI) aided the release into the aqueous media for reduction by ferrous sulfate.展开更多
The effects of ferrous and ferric iron as well as redox potential on copper and iron extraction from the copper flotation concentrate of Sarcheshmeh, Kerman, Iran, were evaluated using shake flask leaching examination...The effects of ferrous and ferric iron as well as redox potential on copper and iron extraction from the copper flotation concentrate of Sarcheshmeh, Kerman, Iran, were evaluated using shake flask leaching examinations. Experiments were carried out in the presence and absence of a mixed culture of moderately thermophile microorganisms at 50?C. Chemical leaching experiments were performed in the absence and presence of 0.15 M iron (ferric added medium, ferrous added medium and a mixture medium regulated at 420 mV, Pt. vs. Ag/AgCl). In addition, bioleaching experiments were carried out in the presence and absence of 0.1 M iron (ferric and ferrous added mediua) at pulp density 10% (w/v), inoculated bacteria 20% (v/v), initial pH 1.6, nutrient medium Norris and yeast extract addition 0.02% (w/w). Abiotic leaching tests showed that the addition of iron at low solution redox potentials significantly increased the rate and extent of copper dissolution but when ferric iron was added, despite a higher initial rate of copper dissolution, leaching process stopped. Addition of both ferrous and ferric iron to the bioleaching medium levelled off the copper extraction and had an inhibitory effect which decreased the final redox potential. The monitoring of ferrous iron, ferric iron and copper extraction in leach solutions gave helpful results to understand the behaviour of iron cations during chemical and bacterial leaching processes.展开更多
In this paper, Fenton process was determined to be an effective technique to treat the refractory Nonylphenol ethoxylates (NPEOs) wastewater. The COD removal efficien-cies above 89% were obtained when the initial COD ...In this paper, Fenton process was determined to be an effective technique to treat the refractory Nonylphenol ethoxylates (NPEOs) wastewater. The COD removal efficien-cies above 89% were obtained when the initial COD concentration was 12000mg/L. However, A large number of ferric sludge (SS=8.724g/L) would be produced after the Fenton oxidation of the wastewater and must be disposed appropriately. A novel process for Fenton sludge reused by low-cost ferrous sulfide (FeS) was also investi-gated. Experimental results show that the Fenton sludge could be reduced to produce a certain amount of Fe2+ in the acidic mixed liquor by ferrous sulfide. This mixed liquor from Fenton sludge could be used as the new catalyst in the Fenton process and was also highly effective for the NPEOs wastewater treatment. The residual ferrous sulfide from the mixed liquor could be used for the next batch of the展开更多
In March 12, former leaders in metallurgy industry circle Gao Yangwen, Lin Zesheng, Duan Dingbo, General Manager of China National Nonferrous Metals Industry Corporation(CNNC)Fei Ziwen, Vice General Manager He Boquan,...In March 12, former leaders in metallurgy industry circle Gao Yangwen, Lin Zesheng, Duan Dingbo, General Manager of China National Nonferrous Metals Industry Corporation(CNNC)Fei Ziwen, Vice General Manager He Boquan, Assistant General Manager Wu Gong, directors展开更多
Dear Sir,I am Dr.Zhe Xu,from the Eye Center,Second Affiliated Hospital,School of Medicine,Zhejiang University,Hangzhou,China.We write to present a case of resolution of siderotic glaucoma after removal of a retained f...Dear Sir,I am Dr.Zhe Xu,from the Eye Center,Second Affiliated Hospital,School of Medicine,Zhejiang University,Hangzhou,China.We write to present a case of resolution of siderotic glaucoma after removal of a retained ferrous foreign body.This study has been performed in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the Second Affiliated Hospital.展开更多
[ Objective] The study aimed to discuss the effects of ferrous fumarate on growth performance, blood biochemical parameters and content of trace element of Oncorhynchus mykiss. [ Method ] Juvenile rainbow trout with a...[ Objective] The study aimed to discuss the effects of ferrous fumarate on growth performance, blood biochemical parameters and content of trace element of Oncorhynchus mykiss. [ Method ] Juvenile rainbow trout with an initial weight of (89.2 ±0.2) g were fed with the basal fodder supplemented with different levels of ferrous fumarate (0, 20, 40, 80,160 and 480 mg/kg iron) for 60 d, and the six groups were named DO, D20, D40, D80, D160 and D480, wherein DO was as the control group, actually containing 62.60, 79.50, 99.60, 139.30, 215.20 and 538.40 mg/kg iron respectively. [ Result] The growth performance of juvenile rainbow trout was not affected by different dietary iron levels obviously ( P 〉 0.05). With the increase of dietary iron level, hemoglobin (Hb) content and number of red blood cells(RBC) rose firstly and then leveled off. No significance was found in hematocrit (Hct) among the six groups (P 〉0.05). Iron content in the whole body, vertebrae and muscle increased significantly with the improvement of dietary iron level( P 〈0.05), and iron concentration in the liver increased firstly and then leveled off in groups from D40 to D480. No significant difference in zinc content of the whole body was found among the six groups ( P〉0.05), while zinc content in the vertebrae and muscle in control group was significantly higher than that of other groups ( P〈0.05), and zinc concentration in the liver in groups DO and 1320 was significantly higher than that of other groups ( P 〈0.05). Copper content in the whole body increased significantly with the increase of dietary iron level (P 〈 0.05 ), while no significant difference was observed in the vertebrae ( P 〉0.05), and copper concentration in the muscle in control group was significantly lower than that of other groups ( P 〈0.05). Serum lysozyme (LZM) activity of group DO was significantly lower than that of other groups ( P 〈 0.05) except for group D480 ( P 〉 0.05). Catalase (CAT) activity of serum enhanced significantly ( P 〈 0.05) from DO to EH0 and then decreased obviously (P 〈0.05). [ Conclusion] Based on hemoglobin and iron content in the liver, the broken-line model analysis showed that the dietary iron level provided by ferrous fumarate for juvenile rainbow trout was estimated to be 99.8 and 100.4 mg/kg respectively in the experiment.展开更多
Pentadecafluorooctanoic acid (PFOA) is environmentally persistent, bioaccumulative, globally distributed and dangerous to human beings. Thus, the degradation of PFOA with effective method remains further exploration. ...Pentadecafluorooctanoic acid (PFOA) is environmentally persistent, bioaccumulative, globally distributed and dangerous to human beings. Thus, the degradation of PFOA with effective method remains further exploration. Here, an Electro-Fenton (EF) system was studied for efficient PFOA degradation, and where a new composite material ferrous hierarchically porous carbon (FHPC) prepared by high temperature activation of MIL-100 (Fe) was applied as the cathode, and 81.4% PFOA (Initial 50 mg/L) elimination was achieved at a low potential of ?0.4 V (pH = 7, 3 h). With the increasing of the activated temperature, the catalytic ability of the materials is decreasing because the reduced surface area reduced and the iron nanoparticles size enlarged. Moreover, the H2O2 and the ?OH were also detected to confirm the dominating contribution of Electro-Fenton mechanism in the PFOA degradation. Thus, this material could be used in efficient heterogeneous EF technology for PFOA elimination.展开更多
Background: For the WHO, anemia is a serious public health problem, with an emphasis on deprivation anemia, which has socioeconomic conditions as determining factors for its development. Among nutritional anemias, the...Background: For the WHO, anemia is a serious public health problem, with an emphasis on deprivation anemia, which has socioeconomic conditions as determining factors for its development. Among nutritional anemias, the most relevant is iron deficiency, whose main form of prevention and treatment is supplementation with ferrous sulfate dispensed in the public health system, with the need to periodically check whether the drug has the quality required by regulatory health agencies. Thus, the objective of this study was to analyze the quality of the ferrous sulfate medication, from the same laboratory, and dispensed in a basic health unit (BHU) and a commercial pharmacy (CF). Materials and Methods: An analytical, qualitative and quantitative study of ferrous sulfate heptahydrate (25 mg/mL in 100 mL syrup), carried out on 20 BHU and 10 from CF, both from the same laboratory, but in different batches. Samples were subjected to organoleptic analysis and verification of iron content, pH, volume and density. Data were compared with values recommended by the Brazilian pharmacopoeia 5th edition. Results: Three batches were evaluated: 4659 of from the CF;4574 from the BHU1, and 4576 from the BHU2, stored in accordance with RDC 304/19 of ANVISA. All showed compliance with some organoleptic characteristics;and stable values in pH (3.61 - CF;3.67 - BHU1;3.65 - BHU2), density (1.079 - CF;1.088 - BHU1;1.086 - BHU2) and individual volume (not less than 95% of the declared value). However, it was not possible to detect the odor of herbs;the average volume of batch BHU1 was below the declared value, and the iron content of both BHUs was above the maximum value of pharmacopoeia standards. Conclusion: Samples did not show full compliance with the physical and chemical parameters evaluated, suggesting deviation in the quality of the medication.展开更多
基金National Key R&D Program of China(2019YFC1904903 and 2020YFC1806504)China Postdoctoral Science Foundation(2020M680757)Fundamental Research Funds for the Central Universities(2022XJHH08).
文摘Novel coal gangue-based persulfate catalyst(CG-FeCl_(2))was successfully synthesized by the means of calcinating under nitrogen atmosphere with the addition of ferrous chloride tetrahydrate(FeCl_(2)·_(4)H_(2)O).The phase transformation of the prepared materials and gas products during the heating process are thoroughly investigated.It is suggested that ferrous chloride participated in the phase transformation and formed Si-O-Fe bonds.And the main gaseous products are H_(2)O,H_(2),and HCl during the heating process.Besides,the ability of CG-FeCl_(2) to activate peroxymonosulfate(PMS)for catalytic degradation of polycyclic aromatic hydrocarbons(PAHs)and phenol was deeply studied.More than 95%of naphthyl,phenanthrene and phenol were removed under optimizied conditions.In addition,1O_(2),·OH,and SO_(4)·−were involved in the CG-FeCl_(2)/PMS system from the free radical scavenging experiment,where 1O_(2) played a major role during the oxidation process.Furthermore,CG-FeCl_(2)/PMS system exhibited superior stability in a relatively wide pH range and the presence of common anion from related degradation experiments.Overall,the novel CG-FeCl_(2) is an efficient and environmentally friendly catalyst,displaying potential application prospect in the field of PAHs and phenol-contaminated wastewater treatment.
基金Item Sponsored by National Natural Science Foundation of China (50204005 ,50374029)
文摘A great amount of ferrous tailings and slag cause severe damage to the ecological environment, which must be reclaimed and utilized. The composition, type, and characteristics of ferrous tailings and slag in China were introduced. The research status and the application outlook of glass ceramics made from ferrous tailings and slag were discussed. Glass ceramics made from ferrous tailings and slag can be applied to various fields, and it will be environmentally conscious materials in the 21st century.
文摘To study the effects of selenium on root oxidizing ability and yield of rice under ferrous stress, a pot culture experiment was conducted, the activity of glutathione peroxidase (GSH-Px) and the concentration of malonaldelyde (MDA) were determined. The root oxidizing ability and yield characters of rice were examined. Results showed that appropriate amount of Se enhanced the activity of glutathione peroxidase and the oxidizing ability of rice roots significantly, reduced the concentration of MDA, increased 1000-grain weight of rice, F = 26.96**, decreased empty and blighted grain rate, increased the rice yield, F = 11.53**, and enhanced the rice resistance under ferrous stress.
基金supported by the National Natural Science Foundation of China(Grant No.U1402234)the Guangxi Scientific Research and Technology Development Plan(Grants No.GuikeAB16380287 and GuikeAB17129025)+2 种基金the Public Welfare Fund of the Ministry of Environmental Protection of China(Grant No.201509049)the Program of International S & T Cooperation(Grant No.2016YFE0130700)the Fund of the General Research Institute for Nonferrous Metals(Grants No.53321 and 53348)
文摘The effect of hydraulic retention time (HRT) and pH on the biooxidation of ferrous iron during simulated acid mine drainage (AMD) treatment was investigated.The simulated AMD was highly acidic (pH 2.5), rich in iron (about 1700 mg/L) and copper (about 200 mg/L), and contained high concentrations of sulfate (about 4700 mg/L).The biooxidation of ferrous iron was studied in a laboratory-scale upflow packed bed bioreactor (PBR).The HRT was shortened stepwise from 40 h to 20 h, 13 h, and 8 h under the acidic environment at a pH value of 2.2.Then, the influent pH value was changed from 2.2 to 1.2 at a constant suitable HRT.Physiochemical and microbial community structure analyses were performed on water samples and stuffing collected from the bioreactor under different conditions.The results indicate that the efficiency of ferrous iron oxidation gradually decreased with the decrease of HRT, and when the HRT exceeded 13 h, ferrous iron in AMD was almost completely oxidized.In addition, the best efficiency of ferrous iron oxidation was achieved at the influent pH value of 1.8.Microbial community structure analyses show that Leptospirillum is the predominant genus attached in the bioreactor, and low influent pH values are suitable for the growth of Leptospirillum.
基金This work was supported by Science Challenge Project(Nos.TZ2016006-0103 and TZ2016006-0107-02)National Natural Science Foundation of China(Nos.90923025 and 51905194)Science Fund for Creative Research Groups of NSFC(No.51621064).The sincere thanks are given to Professor Zhang Xinquan(Shanghai Jiao Tong University)for his comments,and Mr Xu Yongbo for his kind assistance.
文摘Diamond tools play a critical role in ultra-precision machining due to their excellent physical and mechanical material properties,such as that cutting edge can be sharpened to nanoscale accuracy.However,abrasive chemical reactions between diamond and non-diamond-machinable metal elements,including Fe,Cr,Ti,Ni,etc,can cause excessive tool wear in diamond cutting of such metals and most of their alloys.This paper reviews the latest achievements in the chemical wear and wear suppression methods for diamond tools in cutting of ferrous metals.The focus will be on the wear mechanism of diamond tools,and the typical wear reduction methods for diamond cutting of ferrous metals,including ultrasonic vibration cutting,cryogenic cutting,surface nitridation and plasma assisted cutting,etc.Relevant commercially available devices are introduced as well.Furthermore,future research trends in diamond tool wear suppression are discussed and examined.
文摘Reduction rate of ferrous oxide in smelting reduction with iron bath has been studied. The main affecting factors on reduction rate, such as composition of the melt, temperature of molten bath, basicity of slag and the way of supplying carbonaceous materials have also been investigated.
基金Funded by the National High-Tech R&D Program(863 Program)of China(No.2012AA040405)
文摘We numerically simulated and experimentally studied the interfacialcarbon diffusion between diamond tooland workpiece materials.A diffusion modelwith respect to carbon atoms of diamond toolpenetrating into chips and machined surface was established.The numericalsimulation results of the diffusion process revealthat the distribution laws of carbon atoms concentration have a close relationship with the diffusion distance,the diffusion time,and the originalcarbon concentration of the work material.In addition,diamond face cutting tests of die steels with different carbon content are conducted at different depth of cuts and feed rates to verify the previous simulation results.The micro-morphology of the chips is detected by scanning electron microscopy.Energy dispersive X-ray analysis was proposed to investigate the change in carbon content of the chips surface.The experimentalresults of this work are of benefit to a better understanding on the diffusion wear mechanism in single crystaldiamond cutting of ferrous metals.Moreover,the experimentalresults show that the diffusion wear of diamond could be reduced markedly by applying ultrasonic vibration to the cutting toolcompared with conventionalturning.
文摘Objective: To compare the efficacy and compliance of the conventional therapy of iron deficiency anemia (ferrous sulfate) with the new forms of therapy chewable iron tablets: (iron polymaltose complex) in the treatment of iron deficiency anemia in pregnant women. Methods: This Randomized Control Trial study included 290 pregnant women with iron deficiency anemia, and they were randomly allocated to a control group who received ferrous sulfate capsules for two months and study group who received iron polymaltose complex chewable tablets for two months. Complete Blood Picture (hemoglobin level and hematocrit level) and Serum ferritin level were done after four and eight weeks to determine the efficacy. In addition, any complains or side effects had been reported to assess the tolerability of the drugs. Two-factor repeated-measures analysis of variance (ANOVA) was used to compare the change in hemoglobin and serum ferritin levels in both groups. Results: There was no statistical significant difference between the two research groups as regards baseline hemoglobin, and at week 4 from onset of treatment (p values = 0.990, 0.112, consecutively). However, there was statistical significant difference on week 8 of continuous drug intake in both groups in which the iron poly maltose complex research group had significantly higher hemoglobin levels (p value = 0.006). Conclusion: The results of the study showed oral iron polymaltose complex increases Hemoglobin and serum ferritin levels more than oral ferrous sulfate and produces less adverse effects than ferrous sulfate.
文摘The reduction of less stable ferric hydroxides and formation of ferrous phases is critical for the fate of phosphorus in anaerobic soils and sediments. The interaction between ferrous iron and phosphate was investigated experimentally during the reduction of synthetic ferrihydrite with natural organic materials as carbon source. Ferrihydrite was readily reduced by dissimilatory iron reducing bacteria (DIRB) with between 52% and 73% Fe(III) converted to Fe(II) after 31 days, higher than without DIRB. Formation of ferrous phases was linearly coupled to almost complete removal of both aqueous and exchangeable phosphate. Simple model calculations based on the incubation data suggested ferrous phases bound phosphate with a molar ratio of Fe(II):P between 1.14 - 2.25 or a capacity of 246 - 485 mg·P·g-1 Fe(II). XRD analysis indicated that the ratio of Fe(II): P was responsible for the precipitation of vivianite (Fe3(PO4)2·8H2O), a dominant Fe(II) phosphate mineral in incubation systems. When the ratio of Fe(II):P was more than 1.5, the precipitation of Fe(II) phosphate was soundly crystallized to vivianite. Thus, reduction of ferric iron provides a mechanism for the further removal of available phosphate via the production of ferrous phases, with anaerobic soils and sediments potentially exhibiting a higher capacity to bind phosphate than some aerobic systems.
基金financially supported by the Special Project on the Integration of Industry, Education and Research of Guangdong Province, China (No. 20013A090100013)by the High Technology Research and Development Program of Xinjiang Uygur Autonomous Region of China (No. 201407300993)
文摘The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.
文摘This paper discusses the toxicity and mobility of chromium species. And it presents the extent and kinetics of reductive remediation of hexavalent chromium, Cr+ using ferrous ion, Fe2+. Molar ratios of 1:3 and 1:6 of Cr (VI) to Fe (II) were used. Integral method of data analysis showed reaction followed second-order kinetics with R square values near unity. Reaction was initially fast but with a rapid precipitation attributed to Cr (III)-Fe (III) in previous studies. This colloidal precipitate ultimately stops the reaction, which explains while conversion efficiency increases with increased molar ratio of Cr (VI) to Fe (II). The impact of pH was investigated by adjusting the Cr (VI)-Fe (II) medium to pH 2.78, 5.24, 7.00, 9.00 and 11.96 using predetermined drops of acid or base. Reaction was more rapid under alkaline conditions with higher extent of degradation consistent with previous research. In soil system, mass transfer limitation was hardly noticed as high extent of reduction was recorded relative to aqueous phase. The high solubility of Cr (VI) aided the release into the aqueous media for reduction by ferrous sulfate.
文摘The effects of ferrous and ferric iron as well as redox potential on copper and iron extraction from the copper flotation concentrate of Sarcheshmeh, Kerman, Iran, were evaluated using shake flask leaching examinations. Experiments were carried out in the presence and absence of a mixed culture of moderately thermophile microorganisms at 50?C. Chemical leaching experiments were performed in the absence and presence of 0.15 M iron (ferric added medium, ferrous added medium and a mixture medium regulated at 420 mV, Pt. vs. Ag/AgCl). In addition, bioleaching experiments were carried out in the presence and absence of 0.1 M iron (ferric and ferrous added mediua) at pulp density 10% (w/v), inoculated bacteria 20% (v/v), initial pH 1.6, nutrient medium Norris and yeast extract addition 0.02% (w/w). Abiotic leaching tests showed that the addition of iron at low solution redox potentials significantly increased the rate and extent of copper dissolution but when ferric iron was added, despite a higher initial rate of copper dissolution, leaching process stopped. Addition of both ferrous and ferric iron to the bioleaching medium levelled off the copper extraction and had an inhibitory effect which decreased the final redox potential. The monitoring of ferrous iron, ferric iron and copper extraction in leach solutions gave helpful results to understand the behaviour of iron cations during chemical and bacterial leaching processes.
文摘In this paper, Fenton process was determined to be an effective technique to treat the refractory Nonylphenol ethoxylates (NPEOs) wastewater. The COD removal efficien-cies above 89% were obtained when the initial COD concentration was 12000mg/L. However, A large number of ferric sludge (SS=8.724g/L) would be produced after the Fenton oxidation of the wastewater and must be disposed appropriately. A novel process for Fenton sludge reused by low-cost ferrous sulfide (FeS) was also investi-gated. Experimental results show that the Fenton sludge could be reduced to produce a certain amount of Fe2+ in the acidic mixed liquor by ferrous sulfide. This mixed liquor from Fenton sludge could be used as the new catalyst in the Fenton process and was also highly effective for the NPEOs wastewater treatment. The residual ferrous sulfide from the mixed liquor could be used for the next batch of the
文摘In March 12, former leaders in metallurgy industry circle Gao Yangwen, Lin Zesheng, Duan Dingbo, General Manager of China National Nonferrous Metals Industry Corporation(CNNC)Fei Ziwen, Vice General Manager He Boquan, Assistant General Manager Wu Gong, directors
基金Supported by the National Natural Science Foundation of China(No.81800877)the Natural Science Foundation of Zhejiang Province(No.LY15H120001,No.LQ17H120008)。
文摘Dear Sir,I am Dr.Zhe Xu,from the Eye Center,Second Affiliated Hospital,School of Medicine,Zhejiang University,Hangzhou,China.We write to present a case of resolution of siderotic glaucoma after removal of a retained ferrous foreign body.This study has been performed in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the Second Affiliated Hospital.
基金funded by Technical System of Modern Agricultural Industry (nycytx-50 )Agriculture Transfer Fund of Ministry of Science and Technology (03EFN213700155)+1 种基金Scientific and Technological Development Plan Project of Shandong Province (2010-2013)Taishan Scholar Post Fund about Aquatic Animal Nutrient and Feed of Shandong Province(HY201004)
文摘[ Objective] The study aimed to discuss the effects of ferrous fumarate on growth performance, blood biochemical parameters and content of trace element of Oncorhynchus mykiss. [ Method ] Juvenile rainbow trout with an initial weight of (89.2 ±0.2) g were fed with the basal fodder supplemented with different levels of ferrous fumarate (0, 20, 40, 80,160 and 480 mg/kg iron) for 60 d, and the six groups were named DO, D20, D40, D80, D160 and D480, wherein DO was as the control group, actually containing 62.60, 79.50, 99.60, 139.30, 215.20 and 538.40 mg/kg iron respectively. [ Result] The growth performance of juvenile rainbow trout was not affected by different dietary iron levels obviously ( P 〉 0.05). With the increase of dietary iron level, hemoglobin (Hb) content and number of red blood cells(RBC) rose firstly and then leveled off. No significance was found in hematocrit (Hct) among the six groups (P 〉0.05). Iron content in the whole body, vertebrae and muscle increased significantly with the improvement of dietary iron level( P 〈0.05), and iron concentration in the liver increased firstly and then leveled off in groups from D40 to D480. No significant difference in zinc content of the whole body was found among the six groups ( P〉0.05), while zinc content in the vertebrae and muscle in control group was significantly higher than that of other groups ( P〈0.05), and zinc concentration in the liver in groups DO and 1320 was significantly higher than that of other groups ( P 〈0.05). Copper content in the whole body increased significantly with the increase of dietary iron level (P 〈 0.05 ), while no significant difference was observed in the vertebrae ( P 〉0.05), and copper concentration in the muscle in control group was significantly lower than that of other groups ( P 〈0.05). Serum lysozyme (LZM) activity of group DO was significantly lower than that of other groups ( P 〈 0.05) except for group D480 ( P 〉 0.05). Catalase (CAT) activity of serum enhanced significantly ( P 〈 0.05) from DO to EH0 and then decreased obviously (P 〈0.05). [ Conclusion] Based on hemoglobin and iron content in the liver, the broken-line model analysis showed that the dietary iron level provided by ferrous fumarate for juvenile rainbow trout was estimated to be 99.8 and 100.4 mg/kg respectively in the experiment.
文摘Pentadecafluorooctanoic acid (PFOA) is environmentally persistent, bioaccumulative, globally distributed and dangerous to human beings. Thus, the degradation of PFOA with effective method remains further exploration. Here, an Electro-Fenton (EF) system was studied for efficient PFOA degradation, and where a new composite material ferrous hierarchically porous carbon (FHPC) prepared by high temperature activation of MIL-100 (Fe) was applied as the cathode, and 81.4% PFOA (Initial 50 mg/L) elimination was achieved at a low potential of ?0.4 V (pH = 7, 3 h). With the increasing of the activated temperature, the catalytic ability of the materials is decreasing because the reduced surface area reduced and the iron nanoparticles size enlarged. Moreover, the H2O2 and the ?OH were also detected to confirm the dominating contribution of Electro-Fenton mechanism in the PFOA degradation. Thus, this material could be used in efficient heterogeneous EF technology for PFOA elimination.
文摘Background: For the WHO, anemia is a serious public health problem, with an emphasis on deprivation anemia, which has socioeconomic conditions as determining factors for its development. Among nutritional anemias, the most relevant is iron deficiency, whose main form of prevention and treatment is supplementation with ferrous sulfate dispensed in the public health system, with the need to periodically check whether the drug has the quality required by regulatory health agencies. Thus, the objective of this study was to analyze the quality of the ferrous sulfate medication, from the same laboratory, and dispensed in a basic health unit (BHU) and a commercial pharmacy (CF). Materials and Methods: An analytical, qualitative and quantitative study of ferrous sulfate heptahydrate (25 mg/mL in 100 mL syrup), carried out on 20 BHU and 10 from CF, both from the same laboratory, but in different batches. Samples were subjected to organoleptic analysis and verification of iron content, pH, volume and density. Data were compared with values recommended by the Brazilian pharmacopoeia 5th edition. Results: Three batches were evaluated: 4659 of from the CF;4574 from the BHU1, and 4576 from the BHU2, stored in accordance with RDC 304/19 of ANVISA. All showed compliance with some organoleptic characteristics;and stable values in pH (3.61 - CF;3.67 - BHU1;3.65 - BHU2), density (1.079 - CF;1.088 - BHU1;1.086 - BHU2) and individual volume (not less than 95% of the declared value). However, it was not possible to detect the odor of herbs;the average volume of batch BHU1 was below the declared value, and the iron content of both BHUs was above the maximum value of pharmacopoeia standards. Conclusion: Samples did not show full compliance with the physical and chemical parameters evaluated, suggesting deviation in the quality of the medication.