Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide applications.The modification degree of Janus nanosheets inevitably affects their...Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide applications.The modification degree of Janus nanosheets inevitably affects their interfacial activity,which is essential for their performances in enhanced oil recovery(EOR).In this study,the interfacial properties of Janus graphene oxide(JGO)with various modification degrees at liquid-liquid and liquid-solid interfaces were systematically evaluated via the measurements of interfacial tension(IFT),dilatational modulus,contact angle,and EOR efficiency was further assessed by core flooding tests.It is found that JGO-5 with higher modification degree exhibits the greater ability to reduce IFT(15.16 mN/m)and dilatational modulus(26 mN/m).Furthermore,JGO can construct interfacial and climbing film with the assistance of hydrodynamic power to effectively detach the oil from the rock surface and greatly enhance oil recovery.Moderately modified JGO-2 can highly improve recovery of residual crude oil(11.53%),which is regarded as the promising EOR agent in practical application.The present study firstly focuses on the effects of modification degrees on the JGO interfacial properties and proposes diverse EOR mechanisms for JGO with different modification degrees.展开更多
The wear behavior and mild−severe(M−S)wear transition of Mg−10Gd−1.5Y−0.4Zr alloy were investigated within a temperature range of 20−200℃.The morphologies and compositions of worn surfaces were examined to identify t...The wear behavior and mild−severe(M−S)wear transition of Mg−10Gd−1.5Y−0.4Zr alloy were investigated within a temperature range of 20−200℃.The morphologies and compositions of worn surfaces were examined to identify the wear mechanisms using scanning electron microscope and energy dispersive X-ray spectrometer.The microstructure and hardness in the subsurfaces were analyzed to reveal the M−S wear transition mechanism.Under a constant loads of 20,35 and 40 N,each wear rate−test temperature curve presented a turning point which corresponded to the M−S wear transition.In mild wear,the surface material was plastically deformed and hence was strainhardened,whereas in severe wear,the surface material was dynamically recrystallized and consequently was softened.It has been found that the critical temperature for M−S wear transition decreases with increasing the normal load,and the normal load exhibits an almost linear relationship with critical temperature for M−S wear transition.This work reveals that the M−S wear transition of the studied alloy conforms to the surface DRX temperature criterion.展开更多
Danshen, the rhizome of Salvia miltiorrhiza Bunge, has been used in traditional Chinese medicine （TCM） for treatment of various diseases. Tanshinone IIA （TSA） is one of the main active components of Danshen, w...Danshen, the rhizome of Salvia miltiorrhiza Bunge, has been used in traditional Chinese medicine （TCM） for treatment of various diseases. Tanshinone IIA （TSA） is one of the main active components of Danshen, which has multiple bioactivities. This article reviews the research progress of TSA in the treatment of cardiovascular disease, anti-inflammatory and immune, anti-tumor, liver protection, neuroprotection. It provides more ideas for the clinical application of TSA and the development of drug resistance.展开更多
基金grateful for funding from the National Natural Science Foundation of China(Grant No.52174053,52130401 and 51974344)Natural Science Foundation of Shandong Provincial(ZR2019MEE077).
文摘Asymmetrically modified Janus graphene oxide(JGO)has attracted great attention due to its unique physical chemistry properties and wide applications.The modification degree of Janus nanosheets inevitably affects their interfacial activity,which is essential for their performances in enhanced oil recovery(EOR).In this study,the interfacial properties of Janus graphene oxide(JGO)with various modification degrees at liquid-liquid and liquid-solid interfaces were systematically evaluated via the measurements of interfacial tension(IFT),dilatational modulus,contact angle,and EOR efficiency was further assessed by core flooding tests.It is found that JGO-5 with higher modification degree exhibits the greater ability to reduce IFT(15.16 mN/m)and dilatational modulus(26 mN/m).Furthermore,JGO can construct interfacial and climbing film with the assistance of hydrodynamic power to effectively detach the oil from the rock surface and greatly enhance oil recovery.Moderately modified JGO-2 can highly improve recovery of residual crude oil(11.53%),which is regarded as the promising EOR agent in practical application.The present study firstly focuses on the effects of modification degrees on the JGO interfacial properties and proposes diverse EOR mechanisms for JGO with different modification degrees.
基金financial support from the National Natural Science Foundation of China (No.51775226)。
文摘The wear behavior and mild−severe(M−S)wear transition of Mg−10Gd−1.5Y−0.4Zr alloy were investigated within a temperature range of 20−200℃.The morphologies and compositions of worn surfaces were examined to identify the wear mechanisms using scanning electron microscope and energy dispersive X-ray spectrometer.The microstructure and hardness in the subsurfaces were analyzed to reveal the M−S wear transition mechanism.Under a constant loads of 20,35 and 40 N,each wear rate−test temperature curve presented a turning point which corresponded to the M−S wear transition.In mild wear,the surface material was plastically deformed and hence was strainhardened,whereas in severe wear,the surface material was dynamically recrystallized and consequently was softened.It has been found that the critical temperature for M−S wear transition decreases with increasing the normal load,and the normal load exhibits an almost linear relationship with critical temperature for M−S wear transition.This work reveals that the M−S wear transition of the studied alloy conforms to the surface DRX temperature criterion.
文摘Danshen, the rhizome of Salvia miltiorrhiza Bunge, has been used in traditional Chinese medicine （TCM） for treatment of various diseases. Tanshinone IIA （TSA） is one of the main active components of Danshen, which has multiple bioactivities. This article reviews the research progress of TSA in the treatment of cardiovascular disease, anti-inflammatory and immune, anti-tumor, liver protection, neuroprotection. It provides more ideas for the clinical application of TSA and the development of drug resistance.
