Cathodic deposition current density of the composite coatings increases when SiC par-ticles and rare earth (RE) were added in the bath, which is profitable for Ni- W-P alloy to deposit in the cathod, forming Ni-W-P-Si...Cathodic deposition current density of the composite coatings increases when SiC par-ticles and rare earth (RE) were added in the bath, which is profitable for Ni- W-P alloy to deposit in the cathod, forming Ni-W-P-SiC and RE-Ni-W-P-SiC composite coatings. On the contrary, the addition of PTFE in the bath decreases cathodic deposition current density of the coatings. The current density increases a little when the amount of RE is 7-9g/l; however, the current density increases greatly when the amount of RE is increased to 11-13g/l. Bui ij the amount of RE is raised further, the current density decreases. Hardness and wear resistance of RE-Ni-W-P-SiC composite coating have been studied, and the results show that the hardness and wear resistance of RE-Ni-W-P-SiC composite coating increase with increasing heat treatment tempera-ture, which reach peak values at 400℃; while the hardness and wear resistance of the coating decrease with the rise of heat treated temperature continuously.展开更多
Hearing loss is the third leading cause of human disability.Age-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health burden.Noise-induced,ototox...Hearing loss is the third leading cause of human disability.Age-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health burden.Noise-induced,ototoxic,and idiopathic sudden sensorineural are other less common types of acquired hearing loss.The etiology of these conditions is complex and multi-fa ctorial involving an interplay of genetic and environmental factors.Oxidative stress has recently been proposed as a likely linking cause in most types of acquired sensorineural hearing loss.Short non-coding RNA sequences known as microRNAs(miRNAs)have increasingly been shown to play a role in cellular hypoxia and oxidative stress responses including promoting an apoptotic response.Sensory hair cell death is a central histopathological finding in sensorineural hearing loss.As these cells do not regenerate in humans,it underlies the irreversibility of human age-related hearing loss.Ovid EMBASE,Ovid MEDLINE,Web of Science Core Collection,and ClinicalTrials.gov databases over the period August 1,2018 to July 31,2023 were searched with"hearing loss,""hypoxamiRs,""hypoxia,""microRNAs,""ischemia,"and"oxidative stress"text words for English language primary study publications or registered clinical trials.Registe red clinical trials known to the senior author we re also assessed.A total of 222studies were thus identified.After excluding duplicates,editorials,retra ctions,secondary research studies,and non-English language articles,39 primary studies and clinical trials underwent full-text screening.This resulted in 11 animal,in vitro,and/or human subject journal articles and 8 registered clinical trial database entries which form the basis of this narrative review.MiRNAs miR-34a and miR-29b levels increase with age in mice.These miRNAs were demonstrated in human neuroblastoma and murine cochlear cell lines to target Sirtuin 1/peroxisome proliferato r-activated receptor gamma coactivator-1-alpha(SIRT1/P GC-1α),SIRT1p53,and SIRT1/hypoxia-inducible factor 1-alpha展开更多
Background JUNO(The Jiangmen Underground Neutrino Observatory)is a multipurpose neutrino experiment,and it has very strict requirements for the detector.According to the MC simulation for JUNO experiment requirements,...Background JUNO(The Jiangmen Underground Neutrino Observatory)is a multipurpose neutrino experiment,and it has very strict requirements for the detector.According to the MC simulation for JUNO experiment requirements,the Rn concentration in the water of the veto detector should be less than 0.2Bq/m^(3).In order to measure such low Rn concentration,two kinds of high-sensitivity Rn measurement systems have been developed.Method Based on the water system of JUNO prototype,two kinds of high-sensitivity Rn detectors have been developed,namely the Si-PIN Rn detector and the LS Rn detector.The Si-PIN Rn detector uses a Si-PIN photodiode to detect theαfrom ^(214)Po decay and the LS Rn detector detects the coincident signals ofβfrom ^(214)Bi decay andβfrom ^(214)Po decay.Result The background measurement of Si-PIN Rn detector and LS Rn detector is performed to estimate the sensitivity.The sensitivity of Si-PIN Rn detector is around 9.0mBq/m^(3) and the sensitivity of LS Rn detector is around 64.0Bq/m^(3).Conclusion Both of the Si-PIN Rn detector and the LS Rn detector are working well with the JUNO prototype at present,and both of them can be developed as an online Rn concentration monitoring device for JUNO veto detector.展开更多
Background The Jiangmen Underground Neutrino Observatory(JUNO),a 20-kton multipurpose underground liquid scintillator detector,was proposed with the determination of the neutrino mass hierarchy as a primary physics go...Background The Jiangmen Underground Neutrino Observatory(JUNO),a 20-kton multipurpose underground liquid scintillator detector,was proposed with the determination of the neutrino mass hierarchy as a primary physics goal.To veto the cosmogenic background and shield the central detector from the environmental radioactivity,a multi-veto system,which consists of a water Cherenkov detector and a top tracker detector,is required.In order to keep the water quality good and remove the radon from water,an ultrapure water system,a radon removal system and radon concentration measurement system have been designed.Method The JUNO ultrapure water system was designed on the basis of the water system of the Daya Bay experiment.By installing the degassing membrane devices on the water system of JUNO prototype and Daya Bay experiment which can remove radon from water,the radon removal efficiency has been measured at the conditions of different gas–liquid phase pressures and different gas concentrations in water using the radon measurement system.Result Loading carbon dioxide into the water and increasing the inlet water pressure could help to improve the radon removal efficiency of the degassing membrane devices,and the radon concentration in water can be reduced to∼0.1 Bq/m^(3).Conclusion A reliable ultrapure water production and circulation system has been designed to keep the water quality good and to reduce the radon concentration in water for JUNO water Cherenkov detector.The radon concentration in water can satisfy the requirement of JUNO by using the Liqui-Cel degassing membrane devices.展开更多
The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of...The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.展开更多
Background Liquid Argon(LAr)is used as a target material in several current and planned experiments related to dark matter direct searching and neutrino detection.Argon provides excellent pulse shape discrimination(PS...Background Liquid Argon(LAr)is used as a target material in several current and planned experiments related to dark matter direct searching and neutrino detection.Argon provides excellent pulse shape discrimination(PSD)capability,which could separate the electron recoil backgrounds from the expected nuclear recoil signals.As the next-generation photosensors,silicon photon multiplier(SiPM)is expected to replace traditional photon multiplier tubes.Purpose The purpose of this paper is to compare the PSD capability of a LAr detector between using SiPMs as photosensors and using PMTs as photosensors.Methods The PSD capability of a LAr detector is determined through the prompt fraction method,which relies on the analysis of output pulses.These pulses are generated using Monte Carlo simulation,incorporating real single photoelectron pulses obtained from a PMT or a SiPM.Results Three kinds of SiPMs and one kind of PMT have been used to compare the PSD capability of a LAr detector.The use of J-60035 SiPM results in a better PSD capability compared to the use of PMT as a photosensor,while using the other two kinds of SiPM deteriorates the PSD capability.Conclusion SiPM is a promising photosensor candidate for a LAr detector.The better energy resolution could help to improve its PSD capability,while the higher probabilities of cross-talk and after-pulse degrade its PSD capability.Notably,after-pulse has a more significant impact compared to cross-talk because after-pulse influences the energy distribution within the time window,while cross-talk primarily affects the energy resolution of the detector.展开更多
TiC_(x)is an excellent composite strengthening particle and grain refiner for Al alloys.However,the stability of TiC_(x)is poor when solute Si exists in Al alloy melts,which significantly depresses its strengthening a...TiC_(x)is an excellent composite strengthening particle and grain refiner for Al alloys.However,the stability of TiC_(x)is poor when solute Si exists in Al alloy melts,which significantly depresses its strengthening and grain refining effects.In this work,the destabilization mechanisms of the TiC_(x)particles in Al-Si alloy melt with a composition of Al-7Si-7.5TiC were explored via experiments,first-principles calculations and thermodynamic calculations.The experimental results show that Si atoms diffuse into TiC_(x)and Ti atoms are released into the Al melt to form a Ti-rich transition zone during the insulation of TiC_(x)in Al-Si melt,and the TiAlySiz and Al_(4)C_(3)phases are solidified in the Ti-rich zone and at Ti-rich zone/TiC_(x)interface,respectively.The first principles calculations show that the low formation energy of C vacancies facilitates the rapid diffusion of Si atoms in TiC_(x),while the doping of Si atoms reduces the energy barrier of diffusion of Ti atoms in TiC_(x)and promotes the formation of Ti-rich zones.The thermodynamic calculations show that the wide crystallization temperature range of the destabilized product TiAlySiz phase is the key to continuous decomposition of TiC_(x)particles.In addition,the driving force of the main destabilization reaction of TiC_(x)in the Al-Si alloys is about 44 times higher than that in the Al alloys without Si addition.This indicates that the presence of solute Si remarkably promotes the subsequent decomposition process of TiC_(x)in the Al-Si alloy melts.展开更多
Tetracycline(TC)as a common broad-spectrum antibiotic,has been frequently detected in soil and sur-face water.It becomes a great threat to the ecological environment.Here,a device of photocatalysis as-sisted microbial...Tetracycline(TC)as a common broad-spectrum antibiotic,has been frequently detected in soil and sur-face water.It becomes a great threat to the ecological environment.Here,a device of photocatalysis as-sisted microbial fuel cell(photo-MFC)was constructed for TC degradation and energy recovery.In this photo-MFC,cadmium sulfide(CdS)cage photocatalysis can degrade most of TC in a short time.While the Co_(3)O_(4)@C-CC(carbonization and calcination of the ZIF-67 precursor in-situ grown on the carbon cloth(CC))bioanode degrades the rest of TC as well as the photocatalytic products,thus improving the miner-alization.The co-existence of photocatalysis with bioanode changes the microbial community structure of the biofilms.The dominant phylum is Geobacter(60.2%)in normal MFC while that in photo-MFC are Pro-teobacteria(43.5%)and Geobacter(33.2%).Therefore,the synergistic effect of photocatalytic degradation and biodegradation achieves a chemical oxygen demand(COD)removal of 98.6%,which is higher than that of normal MFC(77.6%)or single CdS cage photocatalysis(23.8%).In addition,the photogenerated electrons can be transferred to the cathode,which reduces their combination with holes and increases the electricity generation of MFC,achieving a maximum power density of 3.37 W/m^(2).After degradation,the effluent with 200 mg L^(−1) TC exhibits no visible biotoxity.Furthermore,electrochemical test,finite-difference time-domain(FDTD),density functional theory(DFT)calculation and the free radical trapping experiments verify the possible mechanisms of photocatalytic degradation in this photo-MFC.This strat-egy paves a new way for low energy consumption removal and energy recovery of organic pollutants.展开更多
The oxidation behavior of Ni-based superalloy GH4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%H_(2)O,with Ar+20%O_(2)included for comparison.The presence of H_(2)O is adverse to formation...The oxidation behavior of Ni-based superalloy GH4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%H_(2)O,with Ar+20%O_(2)included for comparison.The presence of H_(2)O is adverse to formation of continuous Cr_(2)O_(3)oxide layer but contributes to generation of big voids.Based on this,Ni^(2+)and Co^(2+)are more easily to diffuse towards the outermost oxide layer(OOL),forming non-protective Ni-and Co-rich oxides with high proportion.This leads to a higher weight gain in Ar+20%H_(2)O than that in Ar+20%O_(2).At elevated temperatures,the spallation of oxide scale occurs while the consumption of Cr is reduced in Ar+20%H_(2)O,and the contents of Ni-and Co-rich oxides at this moment are reduced in the OOL.The oxidation mechanism was also discussed.展开更多
基金The project was supported by Yunnan Provincial Natural Science Foundation (95B11-5).
文摘Cathodic deposition current density of the composite coatings increases when SiC par-ticles and rare earth (RE) were added in the bath, which is profitable for Ni- W-P alloy to deposit in the cathod, forming Ni-W-P-SiC and RE-Ni-W-P-SiC composite coatings. On the contrary, the addition of PTFE in the bath decreases cathodic deposition current density of the coatings. The current density increases a little when the amount of RE is 7-9g/l; however, the current density increases greatly when the amount of RE is increased to 11-13g/l. Bui ij the amount of RE is raised further, the current density decreases. Hardness and wear resistance of RE-Ni-W-P-SiC composite coating have been studied, and the results show that the hardness and wear resistance of RE-Ni-W-P-SiC composite coating increase with increasing heat treatment tempera-ture, which reach peak values at 400℃; while the hardness and wear resistance of the coating decrease with the rise of heat treated temperature continuously.
文摘Hearing loss is the third leading cause of human disability.Age-related hearing loss,one type of acquired sensorineural hearing loss,is largely responsible for this escalating global health burden.Noise-induced,ototoxic,and idiopathic sudden sensorineural are other less common types of acquired hearing loss.The etiology of these conditions is complex and multi-fa ctorial involving an interplay of genetic and environmental factors.Oxidative stress has recently been proposed as a likely linking cause in most types of acquired sensorineural hearing loss.Short non-coding RNA sequences known as microRNAs(miRNAs)have increasingly been shown to play a role in cellular hypoxia and oxidative stress responses including promoting an apoptotic response.Sensory hair cell death is a central histopathological finding in sensorineural hearing loss.As these cells do not regenerate in humans,it underlies the irreversibility of human age-related hearing loss.Ovid EMBASE,Ovid MEDLINE,Web of Science Core Collection,and ClinicalTrials.gov databases over the period August 1,2018 to July 31,2023 were searched with"hearing loss,""hypoxamiRs,""hypoxia,""microRNAs,""ischemia,"and"oxidative stress"text words for English language primary study publications or registered clinical trials.Registe red clinical trials known to the senior author we re also assessed.A total of 222studies were thus identified.After excluding duplicates,editorials,retra ctions,secondary research studies,and non-English language articles,39 primary studies and clinical trials underwent full-text screening.This resulted in 11 animal,in vitro,and/or human subject journal articles and 8 registered clinical trial database entries which form the basis of this narrative review.MiRNAs miR-34a and miR-29b levels increase with age in mice.These miRNAs were demonstrated in human neuroblastoma and murine cochlear cell lines to target Sirtuin 1/peroxisome proliferato r-activated receptor gamma coactivator-1-alpha(SIRT1/P GC-1α),SIRT1p53,and SIRT1/hypoxia-inducible factor 1-alpha
基金This work is supported by Xie Jialin Foundation of Institute of High Energy Physics(IHEP,Y7546150U2).
文摘Background JUNO(The Jiangmen Underground Neutrino Observatory)is a multipurpose neutrino experiment,and it has very strict requirements for the detector.According to the MC simulation for JUNO experiment requirements,the Rn concentration in the water of the veto detector should be less than 0.2Bq/m^(3).In order to measure such low Rn concentration,two kinds of high-sensitivity Rn measurement systems have been developed.Method Based on the water system of JUNO prototype,two kinds of high-sensitivity Rn detectors have been developed,namely the Si-PIN Rn detector and the LS Rn detector.The Si-PIN Rn detector uses a Si-PIN photodiode to detect theαfrom ^(214)Po decay and the LS Rn detector detects the coincident signals ofβfrom ^(214)Bi decay andβfrom ^(214)Po decay.Result The background measurement of Si-PIN Rn detector and LS Rn detector is performed to estimate the sensitivity.The sensitivity of Si-PIN Rn detector is around 9.0mBq/m^(3) and the sensitivity of LS Rn detector is around 64.0Bq/m^(3).Conclusion Both of the Si-PIN Rn detector and the LS Rn detector are working well with the JUNO prototype at present,and both of them can be developed as an online Rn concentration monitoring device for JUNO veto detector.
基金This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA10010300).
文摘Background The Jiangmen Underground Neutrino Observatory(JUNO),a 20-kton multipurpose underground liquid scintillator detector,was proposed with the determination of the neutrino mass hierarchy as a primary physics goal.To veto the cosmogenic background and shield the central detector from the environmental radioactivity,a multi-veto system,which consists of a water Cherenkov detector and a top tracker detector,is required.In order to keep the water quality good and remove the radon from water,an ultrapure water system,a radon removal system and radon concentration measurement system have been designed.Method The JUNO ultrapure water system was designed on the basis of the water system of the Daya Bay experiment.By installing the degassing membrane devices on the water system of JUNO prototype and Daya Bay experiment which can remove radon from water,the radon removal efficiency has been measured at the conditions of different gas–liquid phase pressures and different gas concentrations in water using the radon measurement system.Result Loading carbon dioxide into the water and increasing the inlet water pressure could help to improve the radon removal efficiency of the degassing membrane devices,and the radon concentration in water can be reduced to∼0.1 Bq/m^(3).Conclusion A reliable ultrapure water production and circulation system has been designed to keep the water quality good and to reduce the radon concentration in water for JUNO water Cherenkov detector.The radon concentration in water can satisfy the requirement of JUNO by using the Liqui-Cel degassing membrane devices.
基金supported by the National Key R&D Program of China under Contract No.2022YFA1602200the International Partnership Program of the Chineses Academy of Sciences under Grant No.211134KYSB20200057the STCF Key Technology Research and Development Project.
文摘The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.
基金supported by the National Natural Science Foundation of China(Grant Nos.12275289,11975257,and 12175247)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2023015)the National Key R&D Program of China(Grant No.2016YFA0400304).
文摘Background Liquid Argon(LAr)is used as a target material in several current and planned experiments related to dark matter direct searching and neutrino detection.Argon provides excellent pulse shape discrimination(PSD)capability,which could separate the electron recoil backgrounds from the expected nuclear recoil signals.As the next-generation photosensors,silicon photon multiplier(SiPM)is expected to replace traditional photon multiplier tubes.Purpose The purpose of this paper is to compare the PSD capability of a LAr detector between using SiPMs as photosensors and using PMTs as photosensors.Methods The PSD capability of a LAr detector is determined through the prompt fraction method,which relies on the analysis of output pulses.These pulses are generated using Monte Carlo simulation,incorporating real single photoelectron pulses obtained from a PMT or a SiPM.Results Three kinds of SiPMs and one kind of PMT have been used to compare the PSD capability of a LAr detector.The use of J-60035 SiPM results in a better PSD capability compared to the use of PMT as a photosensor,while using the other two kinds of SiPM deteriorates the PSD capability.Conclusion SiPM is a promising photosensor candidate for a LAr detector.The better energy resolution could help to improve its PSD capability,while the higher probabilities of cross-talk and after-pulse degrade its PSD capability.Notably,after-pulse has a more significant impact compared to cross-talk because after-pulse influences the energy distribution within the time window,while cross-talk primarily affects the energy resolution of the detector.
基金the financial supported from the Key R&D Program of Shaanxi Province,China(No.2020ZDLGY13-01)the innovation team program of material developing and application of key engine components(No.K20220185)the National Natural Science Foundation of China(Nos.52101049,52234009 and 52071262).
文摘TiC_(x)is an excellent composite strengthening particle and grain refiner for Al alloys.However,the stability of TiC_(x)is poor when solute Si exists in Al alloy melts,which significantly depresses its strengthening and grain refining effects.In this work,the destabilization mechanisms of the TiC_(x)particles in Al-Si alloy melt with a composition of Al-7Si-7.5TiC were explored via experiments,first-principles calculations and thermodynamic calculations.The experimental results show that Si atoms diffuse into TiC_(x)and Ti atoms are released into the Al melt to form a Ti-rich transition zone during the insulation of TiC_(x)in Al-Si melt,and the TiAlySiz and Al_(4)C_(3)phases are solidified in the Ti-rich zone and at Ti-rich zone/TiC_(x)interface,respectively.The first principles calculations show that the low formation energy of C vacancies facilitates the rapid diffusion of Si atoms in TiC_(x),while the doping of Si atoms reduces the energy barrier of diffusion of Ti atoms in TiC_(x)and promotes the formation of Ti-rich zones.The thermodynamic calculations show that the wide crystallization temperature range of the destabilized product TiAlySiz phase is the key to continuous decomposition of TiC_(x)particles.In addition,the driving force of the main destabilization reaction of TiC_(x)in the Al-Si alloys is about 44 times higher than that in the Al alloys without Si addition.This indicates that the presence of solute Si remarkably promotes the subsequent decomposition process of TiC_(x)in the Al-Si alloy melts.
基金This work was supported by Natural Science Foundation of Hei-longjiang Province(No.LH2022E050)Interdisciplinary Research Foundation of HIT(No.IR2021215)the National Natural Sci-ence Foundation of China(No.52172278).
文摘Tetracycline(TC)as a common broad-spectrum antibiotic,has been frequently detected in soil and sur-face water.It becomes a great threat to the ecological environment.Here,a device of photocatalysis as-sisted microbial fuel cell(photo-MFC)was constructed for TC degradation and energy recovery.In this photo-MFC,cadmium sulfide(CdS)cage photocatalysis can degrade most of TC in a short time.While the Co_(3)O_(4)@C-CC(carbonization and calcination of the ZIF-67 precursor in-situ grown on the carbon cloth(CC))bioanode degrades the rest of TC as well as the photocatalytic products,thus improving the miner-alization.The co-existence of photocatalysis with bioanode changes the microbial community structure of the biofilms.The dominant phylum is Geobacter(60.2%)in normal MFC while that in photo-MFC are Pro-teobacteria(43.5%)and Geobacter(33.2%).Therefore,the synergistic effect of photocatalytic degradation and biodegradation achieves a chemical oxygen demand(COD)removal of 98.6%,which is higher than that of normal MFC(77.6%)or single CdS cage photocatalysis(23.8%).In addition,the photogenerated electrons can be transferred to the cathode,which reduces their combination with holes and increases the electricity generation of MFC,achieving a maximum power density of 3.37 W/m^(2).After degradation,the effluent with 200 mg L^(−1) TC exhibits no visible biotoxity.Furthermore,electrochemical test,finite-difference time-domain(FDTD),density functional theory(DFT)calculation and the free radical trapping experiments verify the possible mechanisms of photocatalytic degradation in this photo-MFC.This strat-egy paves a new way for low energy consumption removal and energy recovery of organic pollutants.
基金supported by the National Key R&D Program of China(No.2021YFB3700400)National Natural Science Foundation of China(Nos.52074030,51904021,52174294).
文摘The oxidation behavior of Ni-based superalloy GH4742 exposed to water vapor was investigated at 900-1100℃for 50 h in Ar+20%H_(2)O,with Ar+20%O_(2)included for comparison.The presence of H_(2)O is adverse to formation of continuous Cr_(2)O_(3)oxide layer but contributes to generation of big voids.Based on this,Ni^(2+)and Co^(2+)are more easily to diffuse towards the outermost oxide layer(OOL),forming non-protective Ni-and Co-rich oxides with high proportion.This leads to a higher weight gain in Ar+20%H_(2)O than that in Ar+20%O_(2).At elevated temperatures,the spallation of oxide scale occurs while the consumption of Cr is reduced in Ar+20%H_(2)O,and the contents of Ni-and Co-rich oxides at this moment are reduced in the OOL.The oxidation mechanism was also discussed.