The multi-phase field model of grain competitive growth during directional solidification of alloy is established.Solving multi-phase field models for thin interface layer thickness conditions,the grain boundary evolu...The multi-phase field model of grain competitive growth during directional solidification of alloy is established.Solving multi-phase field models for thin interface layer thickness conditions,the grain boundary evolution and grain elimination during the competitive growth of SCN-0.24-wt%camphor model alloy bi-crystals are investigated.The effects of different crystal orientations and pulling velocities on grain boundary microstructure evolution are quantitatively analyzed.The obtained results are shown below.In the competitive growth of convergent bi-crystals,when favorably oriented dendrites are in the same direction as the heat flow and the pulling speed is too large,the orientation angle of the bi-crystal from small to large size is the normal elimination phenomenon of the favorably oriented dendrite,blocking the unfavorably oriented dendrite,and the grain boundary is along the growth direction of the favorably oriented dendrite.When the pulling speed becomes small,the grain boundary shows the anomalous elimination phenomenon of the unfavorably oriented dendrite,eliminating the favorably oriented dendrite.In the process of competitive growth of divergent bi-crystal,when the growth direction of favorably oriented dendrites is the same as the heat flow direction and the orientation angle of unfavorably oriented grains is small,the frequency of new spindles of favorably oriented grains is significantly higher than that of unfavorably oriented grains,and as the orientation angle of unfavorably oriented dendrites becomes larger,the unfavorably oriented grains are more likely to have stable secondary dendritic arms,which in turn develop new primary dendritic arms to occupy the liquid phase grain boundary space,but the grain boundary direction is still parallel to favorably oriented dendrites.In addition,the tertiary dendritic arms on the developed secondary dendritic arms may also be blocked by the surrounding lateral branches from further developing into nascent main axes,this blocking of the tertiary dendritic arms has a random nature,which can have aninfluence on the generation of nascent primary main axes in the grain boundaries.展开更多
Dear Editor,Follicular lymphoma(FL)represents the most common subtype of indolent non-Hodgkin's lymphoma(NHL)with distinct pathological,cytogenetic,and molecular features,accounting for 9.7%of NHLs in China[1].FL ...Dear Editor,Follicular lymphoma(FL)represents the most common subtype of indolent non-Hodgkin's lymphoma(NHL)with distinct pathological,cytogenetic,and molecular features,accounting for 9.7%of NHLs in China[1].FL maintains a differentiation stage similar to germinal center(GC)B cells and is divided into grades 1,2,3A,and 3B[2].Up to 90%of FLs harbor the t(14;18)(q32;q21)/BCL2 apoptosis regula-tor(BCL2)-immunoglobulin heavy locus(IGH)transloca-tion and epigenetic modifier mutations,particularly lysine methyltransferase 2D(KMT2D)and CREB-binding pro-tein(CREBBP)[2].展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52161002,51661020,and 11504149)the Postdoctoral Science Foundation of China(Grant No.2014M560371)the Funds for Distinguished Young Scientists of Lanzhou University of Technology,China(Grant No.J201304)。
文摘The multi-phase field model of grain competitive growth during directional solidification of alloy is established.Solving multi-phase field models for thin interface layer thickness conditions,the grain boundary evolution and grain elimination during the competitive growth of SCN-0.24-wt%camphor model alloy bi-crystals are investigated.The effects of different crystal orientations and pulling velocities on grain boundary microstructure evolution are quantitatively analyzed.The obtained results are shown below.In the competitive growth of convergent bi-crystals,when favorably oriented dendrites are in the same direction as the heat flow and the pulling speed is too large,the orientation angle of the bi-crystal from small to large size is the normal elimination phenomenon of the favorably oriented dendrite,blocking the unfavorably oriented dendrite,and the grain boundary is along the growth direction of the favorably oriented dendrite.When the pulling speed becomes small,the grain boundary shows the anomalous elimination phenomenon of the unfavorably oriented dendrite,eliminating the favorably oriented dendrite.In the process of competitive growth of divergent bi-crystal,when the growth direction of favorably oriented dendrites is the same as the heat flow direction and the orientation angle of unfavorably oriented grains is small,the frequency of new spindles of favorably oriented grains is significantly higher than that of unfavorably oriented grains,and as the orientation angle of unfavorably oriented dendrites becomes larger,the unfavorably oriented grains are more likely to have stable secondary dendritic arms,which in turn develop new primary dendritic arms to occupy the liquid phase grain boundary space,but the grain boundary direction is still parallel to favorably oriented dendrites.In addition,the tertiary dendritic arms on the developed secondary dendritic arms may also be blocked by the surrounding lateral branches from further developing into nascent main axes,this blocking of the tertiary dendritic arms has a random nature,which can have aninfluence on the generation of nascent primary main axes in the grain boundaries.
基金by research fund-ing from the National Natural Science Foundation of China(81830007 and 81900193)Chang Jiang Scholars Program,Shanghai Municipal Education Commission Gaofeng Clinical Medicine(20152206 and 20152208)+1 种基金Shanghai Sailing Program(19YF1430900),Clinical Research Plan of Shanghai Hospital Development Center(SHDC2020CR1032B)and Multicenter Clinical Research Project by Shanghai Jiao Tong University School of Medicine(DLY201601).
文摘Dear Editor,Follicular lymphoma(FL)represents the most common subtype of indolent non-Hodgkin's lymphoma(NHL)with distinct pathological,cytogenetic,and molecular features,accounting for 9.7%of NHLs in China[1].FL maintains a differentiation stage similar to germinal center(GC)B cells and is divided into grades 1,2,3A,and 3B[2].Up to 90%of FLs harbor the t(14;18)(q32;q21)/BCL2 apoptosis regula-tor(BCL2)-immunoglobulin heavy locus(IGH)transloca-tion and epigenetic modifier mutations,particularly lysine methyltransferase 2D(KMT2D)and CREB-binding pro-tein(CREBBP)[2].
