Manganese-zinc ferrite is a kind of very important magnetic ferrite material.The properties of wide absorption band,sensitivity to ultraviolet(UV)light and tumor H_(2)O_(2) promise it to be possibly used as a photothe...Manganese-zinc ferrite is a kind of very important magnetic ferrite material.The properties of wide absorption band,sensitivity to ultraviolet(UV)light and tumor H_(2)O_(2) promise it to be possibly used as a photothermal therapy(PTT),photodynamic therapy(PDT)and chemodynamic therapy(CDT)agent.Based on the unique advantages of rare-earth doped nanoparticles,an Er^(3+),Tm^(3+)co-doped upconversion-mediated nanosystem with manganese-zinc ferrite shell(named as UCNPS@M)was developed through a facile thermal co-decomposition method.The final nanosystems were surface-modified by using dopamine hydrochloride(DA)in order to warrant good biocompatibility(named as UCNPS@M@DA).Under irradiation of near-infrared(NIR)light,UCNPS emit both ultraviolet and visible light.The UV light is mostly abso rbed by manga nese-zinc ferrite shell to produce reactive oxygen species(ROS),which is essential to the potential PDT and CDT effect of nanosystems,and at the same time,Mn_(0.5)Zn_(0.5)Fe2O_(4) can further react with H_(2)O_(2) to promote the efficiency of OH-generation.It is expected that UCNPS@M@DA can act as upconversion luminescence imaging guidance due to the visible emission from UCNPS.In addition,the energy absorbed by the nanosystems can be transferred to heat to realize photothermal effect.Moreover,UCNPS@M@DA was successfully applied as a T_(1)/T_(2)-weighted magnetic resonance imaging(MRI)contrast agent due to the existence of Gd,Mn,and Fe elements.In light of the upconversion luminescence(UCL)imaging from the UCNPS as well as potential PTT,PDT,CDT effect mentioned above,this work provides a possibility to realize cancer multi-model bioimaging guided treatment by using an all-in-one diagnosis and therapy nanosystem through a simple yet powerful strategy.展开更多
The effect of austenitizing temperature and Cr, Mo and Mn addition on microstructure and mechanical properties of V microalloyed medium carbon steel has been studied by means of metallography and mechanical testing. T...The effect of austenitizing temperature and Cr, Mo and Mn addition on microstructure and mechanical properties of V microalloyed medium carbon steel has been studied by means of metallography and mechanical testing. The addition of Cr, Mn and Mo leads to a decrease in yield strength （YS） by approximate 100 MPa in comparison to the base steel. It is assumed that Mn and Mo increase hardenability by promoting the formation of bainitic sheaves （BS）, i.e. by suppressing the formation of ferrite-pearlite and acicular ferrite （FP-AF）. Cr at the level used in this work is not that effective. Presence and packet size of bainitic sheaves decrease the Charpy V-notch impact energy at 20 ℃ （CVN20） in comparison to ferrite-pearlite and acicular ferrite microstructures.展开更多
An oxide ceramic process was adopted to prepare high frequency manganese-zinc(MnZn)power ferrite.In combination with the microstructure analysis of material,the influences of sintering process on initial permeability(...An oxide ceramic process was adopted to prepare high frequency manganese-zinc(MnZn)power ferrite.In combination with the microstructure analysis of material,the influences of sintering process on initial permeability(μ_(i))and high frequency loss in unit volume(P_(cv))of MnZn power ferrite were investigated.The results show that in order to obtain fine microstructure and high frequency properties,the preferable sintering temperature and atmosphere are 1230℃and oxygen partial pressure(P_(O_(2)))of 4%,respectively.展开更多
The effect of acicular ferrite （AF） on banded structures in low-carbon microalloyed steel with Mn segregation during both iso- thermal transformation and continuous cooling processes was studied by dilatometry and m...The effect of acicular ferrite （AF） on banded structures in low-carbon microalloyed steel with Mn segregation during both iso- thermal transformation and continuous cooling processes was studied by dilatometry and microscopic observation. With respect to the iso- thermal transformation process, the specimen isothermed at 550℃ consisted of AF in Mn-poor bands and martensite in Mn-rich bands, whereas the specimen isothermed at 450℃ exhibited two different morphologies of AF that appeared as bands. At a continuous cooling rate in the range of 4 to 50℃/s, a mixture of AF and martensite formed in both segregated bands, and the volume fraction of martensite in Mn-rich bands was always higher than that in Mn-poor bands. An increased cooling rate resulted in a decrease in the difference of martensite volume fraction between Mn-rich and Mn-poor bands and thereby leaded to less distinct microstrucmral banding. The results show that Mn segregation and cooling rate strongly affect the formation of AF-containing banded structures. The formation mechanism of microstructural banding was also discussed.展开更多
Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted fo...Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.展开更多
基金Project supported by the National Natural Science Foundation of China(51872183)"Shuguang Program"supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(19SG38)the National Basic Research Program of China(2016YFA0201600)。
文摘Manganese-zinc ferrite is a kind of very important magnetic ferrite material.The properties of wide absorption band,sensitivity to ultraviolet(UV)light and tumor H_(2)O_(2) promise it to be possibly used as a photothermal therapy(PTT),photodynamic therapy(PDT)and chemodynamic therapy(CDT)agent.Based on the unique advantages of rare-earth doped nanoparticles,an Er^(3+),Tm^(3+)co-doped upconversion-mediated nanosystem with manganese-zinc ferrite shell(named as UCNPS@M)was developed through a facile thermal co-decomposition method.The final nanosystems were surface-modified by using dopamine hydrochloride(DA)in order to warrant good biocompatibility(named as UCNPS@M@DA).Under irradiation of near-infrared(NIR)light,UCNPS emit both ultraviolet and visible light.The UV light is mostly abso rbed by manga nese-zinc ferrite shell to produce reactive oxygen species(ROS),which is essential to the potential PDT and CDT effect of nanosystems,and at the same time,Mn_(0.5)Zn_(0.5)Fe2O_(4) can further react with H_(2)O_(2) to promote the efficiency of OH-generation.It is expected that UCNPS@M@DA can act as upconversion luminescence imaging guidance due to the visible emission from UCNPS.In addition,the energy absorbed by the nanosystems can be transferred to heat to realize photothermal effect.Moreover,UCNPS@M@DA was successfully applied as a T_(1)/T_(2)-weighted magnetic resonance imaging(MRI)contrast agent due to the existence of Gd,Mn,and Fe elements.In light of the upconversion luminescence(UCL)imaging from the UCNPS as well as potential PTT,PDT,CDT effect mentioned above,this work provides a possibility to realize cancer multi-model bioimaging guided treatment by using an all-in-one diagnosis and therapy nanosystem through a simple yet powerful strategy.
基金indebted to Ministry of Education and Science of Serbia for financial support(Project OI174004)
文摘The effect of austenitizing temperature and Cr, Mo and Mn addition on microstructure and mechanical properties of V microalloyed medium carbon steel has been studied by means of metallography and mechanical testing. The addition of Cr, Mn and Mo leads to a decrease in yield strength （YS） by approximate 100 MPa in comparison to the base steel. It is assumed that Mn and Mo increase hardenability by promoting the formation of bainitic sheaves （BS）, i.e. by suppressing the formation of ferrite-pearlite and acicular ferrite （FP-AF）. Cr at the level used in this work is not that effective. Presence and packet size of bainitic sheaves decrease the Charpy V-notch impact energy at 20 ℃ （CVN20） in comparison to ferrite-pearlite and acicular ferrite microstructures.
基金This work was financially supported by the Department of Defense of China(No.41312040509).
文摘An oxide ceramic process was adopted to prepare high frequency manganese-zinc(MnZn)power ferrite.In combination with the microstructure analysis of material,the influences of sintering process on initial permeability(μ_(i))and high frequency loss in unit volume(P_(cv))of MnZn power ferrite were investigated.The results show that in order to obtain fine microstructure and high frequency properties,the preferable sintering temperature and atmosphere are 1230℃and oxygen partial pressure(P_(O_(2)))of 4%,respectively.
基金financially supported by the China National Funds for Distinguished Young Scientists (No. 51325401)the International Thermonuclear Experimental Reactor (ITER) Program Special Project (No. 2014GB125006)+1 种基金the Major State Basic Research Development Program of China (No. 2014CB046805)the Natural Science Foundation of Tianjin City (No. 14JCZDJC38700)
文摘The effect of acicular ferrite （AF） on banded structures in low-carbon microalloyed steel with Mn segregation during both iso- thermal transformation and continuous cooling processes was studied by dilatometry and microscopic observation. With respect to the iso- thermal transformation process, the specimen isothermed at 550℃ consisted of AF in Mn-poor bands and martensite in Mn-rich bands, whereas the specimen isothermed at 450℃ exhibited two different morphologies of AF that appeared as bands. At a continuous cooling rate in the range of 4 to 50℃/s, a mixture of AF and martensite formed in both segregated bands, and the volume fraction of martensite in Mn-rich bands was always higher than that in Mn-poor bands. An increased cooling rate resulted in a decrease in the difference of martensite volume fraction between Mn-rich and Mn-poor bands and thereby leaded to less distinct microstrucmral banding. The results show that Mn segregation and cooling rate strongly affect the formation of AF-containing banded structures. The formation mechanism of microstructural banding was also discussed.
基金the National Natural Science Foundation of China(Grant No.51709103)Natural Science Foundation of Hunan Province,China(Grant Nos.2018JJ3242 and 2021JJ30362)+1 种基金Science and Technology Innovation Leading Plan of High Tech Industry in Hunan Province(Grant No.2021GK4055)Training Program for Excellent Young Innovators of Changsha(Grant No.kq1802020).
文摘Direct chemical oxidation and pure adsorption could not effectively remove p-Arsanilic acid(p-ASA)and the released inor-ganic arsenic.Herein,one novel biochar supported MnFe_(2)O_(4)(MFB)was synthesized and adopted for p-ASA degradation and synchronous adsorption of the generated inorganic arsenic.The MFB/persulfate(PS)system could remain effective under a wide pH range(3.0-9.0),and the released arsenic could be removed simultaneously by MFB.Mechanism investiga-tion revealed that the functional groups of MFB(i.e.O-C=O and C=O),Fe and Mn oxides on MFB all contributed to PS activation.O_(2)^(·−)and^(1)O_(2)were the main reactive oxygen species(ROS)responsible for p-ASA degradation,and^(1)O_(2)was the predominant ROS.Besides,the MFB possessed superior reusability.Therefore,it is expected to develop a potential method for organic arsenic contaminants removal via an oxidation-adsorption process,and the results could also shed light on the better understanding of the PS activation mechanisms.
