The embrittlement of nickel-based structural alloys by fission-produced tellurium(Te) is a major challenge for molten salt reactors(MSR). In this study, the effects of thermal exposure time on tellurium diffusion in a...The embrittlement of nickel-based structural alloys by fission-produced tellurium(Te) is a major challenge for molten salt reactors(MSR). In this study, the effects of thermal exposure time on tellurium diffusion in a candidate MSR structural alloy(Ni–16 Mo–7 Cr–4 Fe) and the consequent mechanical property degradation of the alloy were investigated through surrogate diffusion experiments at 700 °C. The results show that some tellurium reacted with the alloy to form tellurides on the surface,while some tellurium diffused into the alloy along grain boundaries. Ni_3Te_2 and CrTe were the most stable reaction products at the tested temperature, and the formation of CrTe on the surface induced the Cr depletion at grain boundaries of the alloy. The diffusion depth of Te increased gradually with thermal exposure time, and thediffusion rate kept stable within the test duration of up to3000 h. The Te diffusion in the alloy caused the embrittlement of grain boundaries, inducing crack formation and strength degradation in tensile test at room temperature.展开更多
Corrosion test of a Ni–16Mo–7Cr alloy with a decarburized layer was conducted in FLiNaK salt at 700 °C. A detailed microstructure study was performed to investigate the corrosion behavior and mechanisms. The re...Corrosion test of a Ni–16Mo–7Cr alloy with a decarburized layer was conducted in FLiNaK salt at 700 °C. A detailed microstructure study was performed to investigate the corrosion behavior and mechanisms. The results show that the Ferich layers were formed on the corroded alloys with and without decarburization. The surface decarburization had little influence on the corrosion resistance of the alloy, whereas it caused more M_2C carbide formation beneath the corrosion layer. That is attributed to the higher concentration of C gradient near the alloy surface, which was resulted from the increase in C content liberated from graphite crucible wall during the corrosion process.展开更多
In a recent study published in Cell,Wei and colleagues describe the role of canabis in mediating inflammation and oxidative stress induced endothelial dysfunction and thereby contributing to the pathogenesis of athero...In a recent study published in Cell,Wei and colleagues describe the role of canabis in mediating inflammation and oxidative stress induced endothelial dysfunction and thereby contributing to the pathogenesis of atherosclerosis.1 Cardiovascular diseases(CVDs)are still the leading cause of death globally.There is an estimated 17.9 million people died from CVDs in 2019,representing 32%of all global deaths.2 Cannabis,also known as hemp or marijuana,is the most widely cultivated,trafficked and abused illicit drug worldwide especially in Western countries.展开更多
基金supported by the National key research and development program of China(No.2016YFB0700404)the National Natural Science Foundation of China(Nos.51371188,51671122,51671154,51601213,51501216)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA02004210)the Shanghai Sailing Program(No.16YF1414300)the Talent development fund of Shanghai(No.201650)
文摘The embrittlement of nickel-based structural alloys by fission-produced tellurium(Te) is a major challenge for molten salt reactors(MSR). In this study, the effects of thermal exposure time on tellurium diffusion in a candidate MSR structural alloy(Ni–16 Mo–7 Cr–4 Fe) and the consequent mechanical property degradation of the alloy were investigated through surrogate diffusion experiments at 700 °C. The results show that some tellurium reacted with the alloy to form tellurides on the surface,while some tellurium diffused into the alloy along grain boundaries. Ni_3Te_2 and CrTe were the most stable reaction products at the tested temperature, and the formation of CrTe on the surface induced the Cr depletion at grain boundaries of the alloy. The diffusion depth of Te increased gradually with thermal exposure time, and thediffusion rate kept stable within the test duration of up to3000 h. The Te diffusion in the alloy caused the embrittlement of grain boundaries, inducing crack formation and strength degradation in tensile test at room temperature.
基金supported financially by the National Natural Science Foundation of China (Nos. 51601214, 51674237 and 11705264)the National Key Research and Development Program (No. 2017YFA0402803)
文摘Corrosion test of a Ni–16Mo–7Cr alloy with a decarburized layer was conducted in FLiNaK salt at 700 °C. A detailed microstructure study was performed to investigate the corrosion behavior and mechanisms. The results show that the Ferich layers were formed on the corroded alloys with and without decarburization. The surface decarburization had little influence on the corrosion resistance of the alloy, whereas it caused more M_2C carbide formation beneath the corrosion layer. That is attributed to the higher concentration of C gradient near the alloy surface, which was resulted from the increase in C content liberated from graphite crucible wall during the corrosion process.
基金supported by GuangDong Basic and Applied Basic Research Foundation.(No.2022A1515012445 to L.D.).
文摘In a recent study published in Cell,Wei and colleagues describe the role of canabis in mediating inflammation and oxidative stress induced endothelial dysfunction and thereby contributing to the pathogenesis of atherosclerosis.1 Cardiovascular diseases(CVDs)are still the leading cause of death globally.There is an estimated 17.9 million people died from CVDs in 2019,representing 32%of all global deaths.2 Cannabis,also known as hemp or marijuana,is the most widely cultivated,trafficked and abused illicit drug worldwide especially in Western countries.
