Microstructure and alloy element distribution in the welded joint between austenitic stainless steel (1Cr18Ni9Ti) and pearlitic heat-resistant steel (1Cr5Mo) were researched by means of light microscopy, scanning elec...Microstructure and alloy element distribution in the welded joint between austenitic stainless steel (1Cr18Ni9Ti) and pearlitic heat-resistant steel (1Cr5Mo) were researched by means of light microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Microstructure, divisions of the fusion zone and elemental diffusion distributions in the welded joints were investigated. Furthermore, solidification microstructure and S-ferrite distribution in the weld metal of these steels are also discussed.展开更多
The influence of an alternative magnetic field on the growth of the diffusionlayer in Al-Zn diffusion couple was studied. The thickness of the diffusion layer was examined. Theresults show that the alternative magneti...The influence of an alternative magnetic field on the growth of the diffusionlayer in Al-Zn diffusion couple was studied. The thickness of the diffusion layer was examined. Theresults show that the alternative magnetic field increases the thickness of the diffusion layer andthe effect increases with the intensity and frequency of the alternative magnetic field increasing. The growth of the diffusion layer obeys the parabolic rate law and the growth rateincreases with the application of the alternative magnetic field. This growth rate change ismanifested through a change in the frequency factor k_0 and not through a change in the activationenergy Q. The frequency factor k_0 for the diffusion layer growth with the alternative magneticfield is 5.03 cm^2/s and the one without the magnetic field is 3.84 cm^2/s.展开更多
Microbial electrochemical technologies(MET)can remove a variety of organic and inorganic pollutants from contaminated groundwater.However,despite significant laboratory-scale successes over the past decade,field-scale...Microbial electrochemical technologies(MET)can remove a variety of organic and inorganic pollutants from contaminated groundwater.However,despite significant laboratory-scale successes over the past decade,field-scale applications remain limited.We hypothesize that enhancing the electrochemical conductivity of the soil surrounding electrodes could be a groundbreaking and cost-effective alternative to deploying numerous high-surface-area electrodes in short distances.This could be achieved by injecting environmentally safe iron-or carbon-based conductive(nano)particles into the aquifer.Upon transport and deposition onto soil grains,these particles create an electrically conductive zone that can be exploited to control and fine-tune the delivery of electron donors or acceptors over large distances,thereby driving the process more efficiently.Beyond extending the radius of influence of electrodes,these diffuse electro-conductive zones(DECZ)could also promote the development of syntrophic anaerobic communities that degrade contaminants via direct interspecies electron transfer(DIET).In this review,we present the state-of-the-art in applying conductive materials for MET and DIET-based applications.We also provide a comprehensive overview of the physicochemical properties of candidate electrochemically conductive materials and related injection strategies suitable for field-scale implementation.Finally,we illustrate and critically discuss current and prospective electrochemical and geophysical methods for measuring soil electronic conductivitydboth in the laboratory and in the fielddbefore and after injection practices,which are crucial for determining the extent of DECZ.This review article provides critical information for a robust design and in situ implementation of groundwater electro-bioremediation processes.展开更多
The oxidation microstructure and maximum energy product （BH）max loss of a 8m（Co0.76, Fe0.1, Cu0.1, Zr0.04）7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed...The oxidation microstructure and maximum energy product （BH）max loss of a 8m（Co0.76, Fe0.1, Cu0.1, Zr0.04）7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet： a continuous externM oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature （BH）max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of （BH）max loss on oxidation time. It is found that the external oxide scale has little effect on the （BH）max loss, and both the internal reaction layer and diffusion zone result in the （BH）max loss. Moreover, the diffusion zone leads to more （BH）max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91×10^-10 cm^2/s and 6.54×10^-11 cm^2/s, respectively.展开更多
基金The work was supported by the Foundation of KeyLaboratory of Liquid Structure and Heredity of Materi-als, Ministry of Educat
文摘Microstructure and alloy element distribution in the welded joint between austenitic stainless steel (1Cr18Ni9Ti) and pearlitic heat-resistant steel (1Cr5Mo) were researched by means of light microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Microstructure, divisions of the fusion zone and elemental diffusion distributions in the welded joints were investigated. Furthermore, solidification microstructure and S-ferrite distribution in the weld metal of these steels are also discussed.
基金This work was financially supported by the National 863 Foundation of China (No. 2001AA332030)the National Key Basic Research Program (973) (No. G1999064905)
文摘The influence of an alternative magnetic field on the growth of the diffusionlayer in Al-Zn diffusion couple was studied. The thickness of the diffusion layer was examined. Theresults show that the alternative magnetic field increases the thickness of the diffusion layer andthe effect increases with the intensity and frequency of the alternative magnetic field increasing. The growth of the diffusion layer obeys the parabolic rate law and the growth rateincreases with the application of the alternative magnetic field. This growth rate change ismanifested through a change in the frequency factor k_0 and not through a change in the activationenergy Q. The frequency factor k_0 for the diffusion layer growth with the alternative magneticfield is 5.03 cm^2/s and the one without the magnetic field is 3.84 cm^2/s.
基金support under the National Recovery and Resilience Plan(NRRP)Mission 4,Component 2,Investment 1.1,Call for tender No.104 published on February 2,2022 by the Italian Ministry of University and Research(MUR)+2 种基金funded by the European Union e Next GenerationEUe Project Title SteeRing GroundwatEr Electro-bioremediAtion with ConducTIVe ParticlEs(REACTIVE)e CUP:B53D23018110006-Grant Assignment Decree No.1048 adopted on July 14,2023 by the Italian Ministry of University and Research(MUR).UM acknowledges Villum Foundation(grant n.VIL50414)the Grundfos Foundation(grant n.2017-025)LP and GC acknowledge The Geosciences for Sustainable Development project(Budget Ministero dell'Universita e della Ricerca-Dipartimenti di Eccellenza 2023-2027,C93C23002690001).
文摘Microbial electrochemical technologies(MET)can remove a variety of organic and inorganic pollutants from contaminated groundwater.However,despite significant laboratory-scale successes over the past decade,field-scale applications remain limited.We hypothesize that enhancing the electrochemical conductivity of the soil surrounding electrodes could be a groundbreaking and cost-effective alternative to deploying numerous high-surface-area electrodes in short distances.This could be achieved by injecting environmentally safe iron-or carbon-based conductive(nano)particles into the aquifer.Upon transport and deposition onto soil grains,these particles create an electrically conductive zone that can be exploited to control and fine-tune the delivery of electron donors or acceptors over large distances,thereby driving the process more efficiently.Beyond extending the radius of influence of electrodes,these diffuse electro-conductive zones(DECZ)could also promote the development of syntrophic anaerobic communities that degrade contaminants via direct interspecies electron transfer(DIET).In this review,we present the state-of-the-art in applying conductive materials for MET and DIET-based applications.We also provide a comprehensive overview of the physicochemical properties of candidate electrochemically conductive materials and related injection strategies suitable for field-scale implementation.Finally,we illustrate and critically discuss current and prospective electrochemical and geophysical methods for measuring soil electronic conductivitydboth in the laboratory and in the fielddbefore and after injection practices,which are crucial for determining the extent of DECZ.This review article provides critical information for a robust design and in situ implementation of groundwater electro-bioremediation processes.
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2010AA03A401)the National Natural Science Foundation of China (Grant No. 51071010)+1 种基金the Aviation Foundation of China (AFC) (Grant No. 2009ZF51063)the Fundamental Research Funds for the Central Universities
文摘The oxidation microstructure and maximum energy product （BH）max loss of a 8m（Co0.76, Fe0.1, Cu0.1, Zr0.04）7 magnet oxidized at 500 ℃ were systematically investigated. Three different oxidation regions were formed in the oxidized magnet： a continuous externM oxide scale, an internal reaction layer, and a diffusion zone. Both room-temperature and high-temperature （BH）max losses exhibited the same parabolic increase with oxidation time. An oxygen diffusion model was proposed to simulate the dependence of （BH）max loss on oxidation time. It is found that the external oxide scale has little effect on the （BH）max loss, and both the internal reaction layer and diffusion zone result in the （BH）max loss. Moreover, the diffusion zone leads to more （BH）max loss than the internal reaction layer. The values of the oxidation rate constant k for internal reaction layer and oxygen diffusion coefficient D for diffusion zone were obtained, which are about 1.91×10^-10 cm^2/s and 6.54×10^-11 cm^2/s, respectively.
