Vanadium-bearing titanomagnetite carbon composite briquette(VTM-CCB)was proposed as an innovative and promising blast furnace burden to realize low-carbon and high-efficiency ironmaking.To optimize the compositions of...Vanadium-bearing titanomagnetite carbon composite briquette(VTM-CCB)was proposed as an innovative and promising blast furnace burden to realize low-carbon and high-efficiency ironmaking.To optimize the compositions of VTM-CCB based on its softening–melting–dripping characteristics,the evolution behavior and mechanisms of VTM-CCB in cohesive zone and dripping zone were investigated by conducting softening–melting tests under blast furnace conditions.The results show that the structure evolution of VTM-CCB in softening–melting process is correlated to the molten slag,metallic iron,liquid iron,and residual carbon.With the molar ratio of the fixed carbon to the reducible oxygen in iron oxides(FC/O ratio)ranging from 0.8 to 1.0,the VTM-CCB tends to form dense structure and accelerate the softening and melting.With increasing the FC/O ratio to 1.2 and 1.4,the VTM-CCB tends to form concentric circular structure,which could suppress the collapse of packed bed,shift down the location of core cohesive zone,and improve the gas permeability.Although the appropriate increase in FC/O ratio could improve the softening–melting performance of VTM-CCB,a higher FC/O ratio could also promote the precipitation of Ti(C,N),thereby thickening the molten mixtures and deteriorating the dripping behavior.Fully considering the softening–melting–dripping characteristics and permeability,the appropriate FC/O ratio of VTM-CCB should be controlled in the range of 1.0–1.2.展开更多
An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the mag...An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the magnetism, conductivity and biocompatibility of the Fe3O4-RGO nanosheets, the nanocomposites could be facilely adhered to the electrode surface by magnetically controllable assembling and beneficial to achieve the direct redox reactions and electrocatalytic behaviors of GOx immobilized into the nanocomposites. The biosensor exhibited good electrocatalytic activity, high sensitivity and stability. The current response is linear over glucose concentration ranging from 0.05 to 1.5 m M with a low detection limit of0.15 μM. Meanwhile, validation of the applicability of the biosensor was carried out by determining glucose in serum samples. The proposed protocol is simple, inexpensive and convenient, which shows great potential in biosensing application.展开更多
基金National Natural Science Foundation of China(U1808212),Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJB45002)Postdoctoral Research Foundation of Jiangsu Province(7114451120)Transformation Program of Scientific and Technological Achievements of Inner Mongolia Autonomous Region(2019CG073).
文摘Vanadium-bearing titanomagnetite carbon composite briquette(VTM-CCB)was proposed as an innovative and promising blast furnace burden to realize low-carbon and high-efficiency ironmaking.To optimize the compositions of VTM-CCB based on its softening–melting–dripping characteristics,the evolution behavior and mechanisms of VTM-CCB in cohesive zone and dripping zone were investigated by conducting softening–melting tests under blast furnace conditions.The results show that the structure evolution of VTM-CCB in softening–melting process is correlated to the molten slag,metallic iron,liquid iron,and residual carbon.With the molar ratio of the fixed carbon to the reducible oxygen in iron oxides(FC/O ratio)ranging from 0.8 to 1.0,the VTM-CCB tends to form dense structure and accelerate the softening and melting.With increasing the FC/O ratio to 1.2 and 1.4,the VTM-CCB tends to form concentric circular structure,which could suppress the collapse of packed bed,shift down the location of core cohesive zone,and improve the gas permeability.Although the appropriate increase in FC/O ratio could improve the softening–melting performance of VTM-CCB,a higher FC/O ratio could also promote the precipitation of Ti(C,N),thereby thickening the molten mixtures and deteriorating the dripping behavior.Fully considering the softening–melting–dripping characteristics and permeability,the appropriate FC/O ratio of VTM-CCB should be controlled in the range of 1.0–1.2.
基金supported by the National Natural Science Foundation of China (21373138)Shanghai Sci. & Tech. Committee (12JC1407200)Program for Changjiang Scholars and Innovative Research Team in University (IRT1269)
文摘An electrochemical biosensing platform was developed based on glucose oxidase(GOx)/Fe3O4-reduced graphene oxide(Fe3O4-RGO) nanosheets loaded on the magnetic glassy carbon electrode(MGCE).With the advantages of the magnetism, conductivity and biocompatibility of the Fe3O4-RGO nanosheets, the nanocomposites could be facilely adhered to the electrode surface by magnetically controllable assembling and beneficial to achieve the direct redox reactions and electrocatalytic behaviors of GOx immobilized into the nanocomposites. The biosensor exhibited good electrocatalytic activity, high sensitivity and stability. The current response is linear over glucose concentration ranging from 0.05 to 1.5 m M with a low detection limit of0.15 μM. Meanwhile, validation of the applicability of the biosensor was carried out by determining glucose in serum samples. The proposed protocol is simple, inexpensive and convenient, which shows great potential in biosensing application.
