Several body-centered-cubic(BCC)refractory high entropy alloys(HEAs),i.e.,Hf Nb Ta Ti Zr,Nb Ta Ti Zr,Hf Nb Ti Zr and Nb Ti Zr,were annealed at intermediate temperatures for 100 h,and their microstructures and aging be...Several body-centered-cubic(BCC)refractory high entropy alloys(HEAs),i.e.,Hf Nb Ta Ti Zr,Nb Ta Ti Zr,Hf Nb Ti Zr and Nb Ti Zr,were annealed at intermediate temperatures for 100 h,and their microstructures and aging behaviors were studied in detail.All these HEAs start to decompose into multiple phases at around 500°C,but reenter the single-phase region at significantly different temperatures which were determined to be 900,1000,1100 and above 1300°C for Hf Nb Ti Zr,Nb Ti Zr,Hf Nb Ta Ti Zr and Nb Ta Ti Zr,respectively.Our analysis indicates that the onset decomposition temperature in these four HEAs is closely related to the elemental diffusion rates while the ending decomposition temperature is strongly dependent on the elemental melting points.Our findings are important not only for understanding phase stability of HEAs in general,but also for adjusting processing parameters to optimize mechanical properties of these HEAs.展开更多
Tumor cells escape host immune surveillance bydown-regulation of MHC and/or co-stimulatorymolecules.Anti-tumor immune responses are mediated primarily by T cells.A deficiency in either MHC or co-stimulatory molecules ...Tumor cells escape host immune surveillance bydown-regulation of MHC and/or co-stimulatorymolecules.Anti-tumor immune responses are mediated primarily by T cells.A deficiency in either MHC or co-stimulatory molecules on tumor cells is associated with a failure to induce anti-tumor immunity.展开更多
A simplified technique is described for calculating the heat loss coefficient from the absorber of the solar flat-plate collector with a combined honeycomb.The problem is treated in two ways:the coupled mode and the d...A simplified technique is described for calculating the heat loss coefficient from the absorber of the solar flat-plate collector with a combined honeycomb.The problem is treated in two ways:the coupled mode and the decoupled mode.In the analysis,the cell wall and glass cover are assumed to be specularly reflecting and diffusely emitting surfaces,while the absorber is a diffusely reflecting and emitting surface.The influences of emissivities of the absorber and the cell wall as well as the aspect ratio on the heat loss coefficient are predicted.The theoretical results are compared with experimental data reported in the literature,and the agreement is good.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11790293,51871016,51671021,51971017,51921001)111 Project(No.B07003)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China(No.IRT_14R05)the financial support from the National Key Basic Research Program,China(No.2016YFB0300502)。
文摘Several body-centered-cubic(BCC)refractory high entropy alloys(HEAs),i.e.,Hf Nb Ta Ti Zr,Nb Ta Ti Zr,Hf Nb Ti Zr and Nb Ti Zr,were annealed at intermediate temperatures for 100 h,and their microstructures and aging behaviors were studied in detail.All these HEAs start to decompose into multiple phases at around 500°C,but reenter the single-phase region at significantly different temperatures which were determined to be 900,1000,1100 and above 1300°C for Hf Nb Ti Zr,Nb Ti Zr,Hf Nb Ta Ti Zr and Nb Ta Ti Zr,respectively.Our analysis indicates that the onset decomposition temperature in these four HEAs is closely related to the elemental diffusion rates while the ending decomposition temperature is strongly dependent on the elemental melting points.Our findings are important not only for understanding phase stability of HEAs in general,but also for adjusting processing parameters to optimize mechanical properties of these HEAs.
文摘Tumor cells escape host immune surveillance bydown-regulation of MHC and/or co-stimulatorymolecules.Anti-tumor immune responses are mediated primarily by T cells.A deficiency in either MHC or co-stimulatory molecules on tumor cells is associated with a failure to induce anti-tumor immunity.
基金supported by the National Natural Science Foundation of China
文摘A simplified technique is described for calculating the heat loss coefficient from the absorber of the solar flat-plate collector with a combined honeycomb.The problem is treated in two ways:the coupled mode and the decoupled mode.In the analysis,the cell wall and glass cover are assumed to be specularly reflecting and diffusely emitting surfaces,while the absorber is a diffusely reflecting and emitting surface.The influences of emissivities of the absorber and the cell wall as well as the aspect ratio on the heat loss coefficient are predicted.The theoretical results are compared with experimental data reported in the literature,and the agreement is good.
