Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,ma...Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.展开更多
Far-¯eld°uorescence microscopy has made great progress in the spatial resolution,limited by light diffraction,since the super-resolution imaging technology appeared.And stimulated emission depletion(STED)mic...Far-¯eld°uorescence microscopy has made great progress in the spatial resolution,limited by light diffraction,since the super-resolution imaging technology appeared.And stimulated emission depletion(STED)microscopy and structured illumination microscopy(SIM)can be grouped into one class of the super-resolution imaging technology,which use pattern illumination strategy to circumvent the di®raction limit.We simulated the images of the beads of SIM imaging,the intensity distribution of STED excitation light and depletion light in order to observe effects of the polarized light on imaging quality.Compared to¯xed linear polarization,circularly polarized light is more suitable for SIM on reconstructed image.And right-handed circular polarization(CP)light is more appropriate for both the excitation and depletion light in STED system.Therefore the right-handed CP light would be the best candidate when the SIM and STED are combined into one microscope.Good understanding of the polarization will provide a reference for the patterned illumination experiment to achieve better resolution and better image quality.展开更多
Previous studies showed that signifi cant increases in elongation in Mg–Ce alloys due to the Ce addition and the solute drag eff ect by Ce addition were ascribed to the non-basal dislocation slip activating and the t...Previous studies showed that signifi cant increases in elongation in Mg–Ce alloys due to the Ce addition and the solute drag eff ect by Ce addition were ascribed to the non-basal dislocation slip activating and the texture altering. The microstructure evolution and deformation models of extruded Mg-0.5 wt%Ce alloy rods under uniaxial tension have been studied using in situ electron backscatter diff raction. The basal and non-basal slips were characterized by using slip line trace analysis. The results provide evidence for that pyramidal slip activated during deformation, besides basal slip and extension twinning, which contributes to the texture weakening and ductility increasing in Mg-0.5 wt%Ce alloy.展开更多
A martensitic stainless steel AISI420 fabricated by selective laser melting(SLM)and post-processed by austenitizing and tempering heat treatment was investigated in this study.The as-fabricated SLMed AISI420 showed a ...A martensitic stainless steel AISI420 fabricated by selective laser melting(SLM)and post-processed by austenitizing and tempering heat treatment was investigated in this study.The as-fabricated SLMed AISI420 showed a strong mechanical property anisotropy and low ductility in the longitudinal direction.Detailed microstructural characterization revealed the presence of austenite and a relatively sharp solidification texture in the as-fabricated state,while the sharp texture was considered as the cause for the mechanical property anisotropy.In contrast,a fully martensitic microstructure with a very weak texture was achieved after the austenitizing and tempering heat treatment.The mechanical property anisotropy was also fully eliminated,witnessing a significant improvement in the ductility,and thus,comparable mechanical performance with the wrought product was achieved in this study.展开更多
The grain boundary character distribution(GBCD) optimization and its effect on the intergranular stress corrosion cracking(IGSCC) resistance in a cold-rolled and subsequently annealed Fe-18 Cr-17 Mn-2 Mo-0.85 N high-n...The grain boundary character distribution(GBCD) optimization and its effect on the intergranular stress corrosion cracking(IGSCC) resistance in a cold-rolled and subsequently annealed Fe-18 Cr-17 Mn-2 Mo-0.85 N high-nitrogen nickel-free austenitic stainless steel were systematically explored.The results show that stacking faults and planar slip bands appearing at the right amount of deformation(lower than 10%) are beneficial cold-rolled microstructures to the GBCD optimization.The proportion of special boundaries gradually increases in the subsequent stages of recrystallization and grain growth,accompanying with the growth of twin-related domain in the experimental steel.In this way,the fraction of low ∑ coincidence site lattice(CSL) boundaries can reach as high as 82.85% for the specimen cold-rolled by 5% and then annealed at 1423 K for 72 h.After GBCD optimization,low ∑ CSL boundaries and the special triple junctions(J2,J3) of high proportion can greatly hinder the nitride precipitation along grain boundaries and enhance the capability for intergranular crack arrest,thus improving the IGSCC resistance of the experimental steel.展开更多
基金supported by the Deanship of Scienti c Research at King Saud University for funding under Research Group(No.RG1440-021).
文摘Zinc oxide is recently being used as a magnetic semiconductor with the introduction of mag-netic elements.In this work,we report phase pure synthesis of Mg and Ni co-substituted ZnO to explore its structure,optical,magnetic and photo-catalytic properties.X-ray di raction analysis reveals the hexagonal wurtzite type structure having P63mc space group without any impurity phase.UV-Vis spectrophotometry demonstrates the variation in bandgap with the addition of Mg and Ni content in ZnO matrix.Magnetic measurements exhibit a clear boosted magnetization in Ni and Mg co-doped compositions with its stable value of bandgap corroborating the structural stability and magnetic tuning for its advanced applications in modern-day spintronic devices.Photo-catalytic measurements performed using methyl green degradation demonstrate an enhanced trend of activity in Mg and Ni co-doped compositions.
基金This work was partly supported by the National Key Basic Research Program of China (973 project)under Grant No.2015CB352006the National Natural Science Foundation of China under Grant Nos.61335011 and 61405035Program for Changjiang Scholars and Innovative Research Team in University under Grant No.IRT 15R10.
文摘Far-¯eld°uorescence microscopy has made great progress in the spatial resolution,limited by light diffraction,since the super-resolution imaging technology appeared.And stimulated emission depletion(STED)microscopy and structured illumination microscopy(SIM)can be grouped into one class of the super-resolution imaging technology,which use pattern illumination strategy to circumvent the di®raction limit.We simulated the images of the beads of SIM imaging,the intensity distribution of STED excitation light and depletion light in order to observe effects of the polarized light on imaging quality.Compared to¯xed linear polarization,circularly polarized light is more suitable for SIM on reconstructed image.And right-handed circular polarization(CP)light is more appropriate for both the excitation and depletion light in STED system.Therefore the right-handed CP light would be the best candidate when the SIM and STED are combined into one microscope.Good understanding of the polarization will provide a reference for the patterned illumination experiment to achieve better resolution and better image quality.
基金the financial supports of the National Key Research and Development Plan(Grant Nos.2016YFB0301103 and 2016YFB0701201)the National Natural Science Foundation of China(Grant Nos.51771109 and 51631006)
文摘Previous studies showed that signifi cant increases in elongation in Mg–Ce alloys due to the Ce addition and the solute drag eff ect by Ce addition were ascribed to the non-basal dislocation slip activating and the texture altering. The microstructure evolution and deformation models of extruded Mg-0.5 wt%Ce alloy rods under uniaxial tension have been studied using in situ electron backscatter diff raction. The basal and non-basal slips were characterized by using slip line trace analysis. The results provide evidence for that pyramidal slip activated during deformation, besides basal slip and extension twinning, which contributes to the texture weakening and ductility increasing in Mg-0.5 wt%Ce alloy.
基金supported by the National Key R&D Program of China(Grant No.2018YFB1106100)the Shanghai Science and Technology Talents Program Fund(No.19XD1431600)the Shanghai Research Center of Complex Metal Parts by Additive Manufacturing(No.14DZ2253600)。
文摘A martensitic stainless steel AISI420 fabricated by selective laser melting(SLM)and post-processed by austenitizing and tempering heat treatment was investigated in this study.The as-fabricated SLMed AISI420 showed a strong mechanical property anisotropy and low ductility in the longitudinal direction.Detailed microstructural characterization revealed the presence of austenite and a relatively sharp solidification texture in the as-fabricated state,while the sharp texture was considered as the cause for the mechanical property anisotropy.In contrast,a fully martensitic microstructure with a very weak texture was achieved after the austenitizing and tempering heat treatment.The mechanical property anisotropy was also fully eliminated,witnessing a significant improvement in the ductility,and thus,comparable mechanical performance with the wrought product was achieved in this study.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51871048 and 52171108)the Fundamental Research Funds for the Central Universities(Grant Nos.N2002014 and N2202011)。
文摘The grain boundary character distribution(GBCD) optimization and its effect on the intergranular stress corrosion cracking(IGSCC) resistance in a cold-rolled and subsequently annealed Fe-18 Cr-17 Mn-2 Mo-0.85 N high-nitrogen nickel-free austenitic stainless steel were systematically explored.The results show that stacking faults and planar slip bands appearing at the right amount of deformation(lower than 10%) are beneficial cold-rolled microstructures to the GBCD optimization.The proportion of special boundaries gradually increases in the subsequent stages of recrystallization and grain growth,accompanying with the growth of twin-related domain in the experimental steel.In this way,the fraction of low ∑ coincidence site lattice(CSL) boundaries can reach as high as 82.85% for the specimen cold-rolled by 5% and then annealed at 1423 K for 72 h.After GBCD optimization,low ∑ CSL boundaries and the special triple junctions(J2,J3) of high proportion can greatly hinder the nitride precipitation along grain boundaries and enhance the capability for intergranular crack arrest,thus improving the IGSCC resistance of the experimental steel.