The continuous mediums are divided into two kinds according to their geometrical configurations,the first one is related to Euclidian manifolds and the other one to Riemannian manifolds/surfaces in the point of view o...The continuous mediums are divided into two kinds according to their geometrical configurations,the first one is related to Euclidian manifolds and the other one to Riemannian manifolds/surfaces in the point of view of the modern geometry.Two kinds of finite deformation theories with respect to Euclidian and Riemannian manifolds have been developed in the present paper.Both kinds of theories include the definitions of initial and current physical and parametric configurations,deformation gradient tensors with properties,deformation descriptions,transport theories and governing equations of nature conservation laws.The essential property of the theory with respect to Euclidian manifolds is that the curvilinear coordinates corresponding to the current physical configurations include time explicitly through which the geometrically irregular and time varying physical configurations can be mapped in the diffeomorphism manner to the regular and fixed domains in the parametric space.It is quite essential to the study of the relationships between geometries and mechanics.The theory with respect to Riemannian manifolds provides the systemic ideas and methods to study the deformations of continuous mediums whose geometrical configurations can be considered as general surfaces.The essential property of the theory with respect to Riemannian manifolds is that the thickness variation of a patch of continuous medium is represented by the surface density and its governing equation is rigorously deduced.As some applications,wakes of cylinders with deformable boundaries on the plane,incompressible wakes of a circular cylinder on fixed surfaces and axisymmetric finite deformations of an elastic membrane are numerically studied.展开更多
We investigated phase transition and precipitation of ultra-high strength steel（UHSS）in a new ＂short process＂ with controlled rolling and controlled cooling.Thermalexpansion test combined with metallographic obser...We investigated phase transition and precipitation of ultra-high strength steel（UHSS）in a new ＂short process＂ with controlled rolling and controlled cooling.Thermalexpansion test combined with metallographic observation was used to research the continuous cooling transformation（CCT）curve.Moreover,the microstructuraltransformation and precipitation law was revealed by morphologicalobservation and alloying elements by electron probe micro-analyzer（EPMA）.Transmission electron microscopy（TEM）was utilized to analyze the composition and grain orientation of microstructure.The study showed that the measured criticaltransformation temperatures of Ac1 and Ac3 were 746 and 868 ℃,respectively.The CCT curve indicated that the undercooled austenite was transformed into proeutectoid ferrite and bainite with HV 520 in a broad range of cooling rate 0.1^（-1） ℃·s^（-1）.When subjected to a cooling rate of 1 ℃·s^（-1）,the undercooled austenite was divided into small-sized blocks by formed martensite.With further increase of cooling rate,micro-hardness increased dramatically,the microstructure of specimen was mainly lathe bainite（LB）,granular bainite（GB）,lath martensite（LM）and residualaustenite.By diffraction test analysis,it was identified that there was K-S orientation relationship between martensite and austenite for {110}_α//{111}_γ,{111}_α//{101}_γ.EPMA clearly showed that carbon diffused adequately due to staying for a long time at high temperature with a lower cooling rate of 2 ℃·s-1.Phase transition drive force was lower and the residualaustenite existed in the block form of Martensite austenite island（M-A）.With the increase of cooling rate to 10 ℃·s^（-1）,the block residualaustenite reduced,the carbon content of residualaustenite increased and α phase around the residualaustenite formed into a low carbon bainite form.展开更多
In vitro evaluation of novel therapeutic approaches often fails to reliably predict efficacy and toxicity,especially when recapitulating conditions involving recirculating cells.Current testing strategies are often ba...In vitro evaluation of novel therapeutic approaches often fails to reliably predict efficacy and toxicity,especially when recapitulating conditions involving recirculating cells.Current testing strategies are often based on static co-culturing of cells in suspension and 3D tissue models,where cell sedimentation on the target tissue can occur.The observed effects may then mostly be a consequence of sedimentation and of the corresponding forced cell-tissue interactions.The realization of continuous medium flow helps to better recapitulate physiological conditions and cell-tissue interactions.To tackle current limitations of perfused organ-on-chip approaches,we developed a microfluidic chip and operation concept,which prevents undesired sedimentation and accumulation of suspended cells during multiple days by relying on gravity-driven perfusion.Our platform,which we termed“human immune flow(hiFlow)chip”,enables to co-culture cells in suspension with up to 7 preformed microtissue models.Here,we present the design principle and operation of the platform,and we validate its performance by culturing cells and microtissues of a variety of different origins.Cells and tissues could be monitored on chip via high-resolution microscopy,while cell suspensions and microtissues could be easily retrieved for off-chip analysis.Our results demonstrate that primary immune cells and a range of different spheroid models of healthy and diseased tissues can be maintained for over 6 days on chip.As proof-of-concept cell-tissue interaction assay,we used an antibody treatment against diffuse midline glioma,a highly aggressive pediatric tumor.We are confident that our platform will help to increase the prediction power of in vitro preclinical testing of novel therapeutics that rely on the interaction of circulating cells with organ tissues.展开更多
α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of ...α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated bY Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed.展开更多
基金supported by the National Nature Science Foundation of China (Grant Nos. 11172069 and 10872051)some key project of education reforms issued by the Shanghai Municipal Education Commission (2011)
文摘The continuous mediums are divided into two kinds according to their geometrical configurations,the first one is related to Euclidian manifolds and the other one to Riemannian manifolds/surfaces in the point of view of the modern geometry.Two kinds of finite deformation theories with respect to Euclidian and Riemannian manifolds have been developed in the present paper.Both kinds of theories include the definitions of initial and current physical and parametric configurations,deformation gradient tensors with properties,deformation descriptions,transport theories and governing equations of nature conservation laws.The essential property of the theory with respect to Euclidian manifolds is that the curvilinear coordinates corresponding to the current physical configurations include time explicitly through which the geometrically irregular and time varying physical configurations can be mapped in the diffeomorphism manner to the regular and fixed domains in the parametric space.It is quite essential to the study of the relationships between geometries and mechanics.The theory with respect to Riemannian manifolds provides the systemic ideas and methods to study the deformations of continuous mediums whose geometrical configurations can be considered as general surfaces.The essential property of the theory with respect to Riemannian manifolds is that the thickness variation of a patch of continuous medium is represented by the surface density and its governing equation is rigorously deduced.As some applications,wakes of cylinders with deformable boundaries on the plane,incompressible wakes of a circular cylinder on fixed surfaces and axisymmetric finite deformations of an elastic membrane are numerically studied.
基金Funded by the Scientifi c and Technological Research Program of Chongqing Municipal Education Commission(No.KJ1501324)the General Project of Chongqing Frontier and Applied Basic Research Project(No.cstc2015jcyj A90005)the Research Foundation of Chongqing University of Science and Technology(Nos.CK2013Z16&CK2014Z20)
文摘We investigated phase transition and precipitation of ultra-high strength steel（UHSS）in a new ＂short process＂ with controlled rolling and controlled cooling.Thermalexpansion test combined with metallographic observation was used to research the continuous cooling transformation（CCT）curve.Moreover,the microstructuraltransformation and precipitation law was revealed by morphologicalobservation and alloying elements by electron probe micro-analyzer（EPMA）.Transmission electron microscopy（TEM）was utilized to analyze the composition and grain orientation of microstructure.The study showed that the measured criticaltransformation temperatures of Ac1 and Ac3 were 746 and 868 ℃,respectively.The CCT curve indicated that the undercooled austenite was transformed into proeutectoid ferrite and bainite with HV 520 in a broad range of cooling rate 0.1^（-1） ℃·s^（-1）.When subjected to a cooling rate of 1 ℃·s^（-1）,the undercooled austenite was divided into small-sized blocks by formed martensite.With further increase of cooling rate,micro-hardness increased dramatically,the microstructure of specimen was mainly lathe bainite（LB）,granular bainite（GB）,lath martensite（LM）and residualaustenite.By diffraction test analysis,it was identified that there was K-S orientation relationship between martensite and austenite for {110}_α//{111}_γ,{111}_α//{101}_γ.EPMA clearly showed that carbon diffused adequately due to staying for a long time at high temperature with a lower cooling rate of 2 ℃·s-1.Phase transition drive force was lower and the residualaustenite existed in the block form of Martensite austenite island（M-A）.With the increase of cooling rate to 10 ℃·s^（-1）,the block residualaustenite reduced,the carbon content of residualaustenite increased and α phase around the residualaustenite formed into a low carbon bainite form.
基金the support for flow cytometry and microscopy by the single cell facility(SCF)at the Department of Biosystems Science and Engineering at ETH Zurichfinancially supported by the Innosuisse grant 38880.1 IP-LS.by the“Personalized Health and Related Technologies(PHRT)”of the ETH Domain(Project#2021-351).
文摘In vitro evaluation of novel therapeutic approaches often fails to reliably predict efficacy and toxicity,especially when recapitulating conditions involving recirculating cells.Current testing strategies are often based on static co-culturing of cells in suspension and 3D tissue models,where cell sedimentation on the target tissue can occur.The observed effects may then mostly be a consequence of sedimentation and of the corresponding forced cell-tissue interactions.The realization of continuous medium flow helps to better recapitulate physiological conditions and cell-tissue interactions.To tackle current limitations of perfused organ-on-chip approaches,we developed a microfluidic chip and operation concept,which prevents undesired sedimentation and accumulation of suspended cells during multiple days by relying on gravity-driven perfusion.Our platform,which we termed“human immune flow(hiFlow)chip”,enables to co-culture cells in suspension with up to 7 preformed microtissue models.Here,we present the design principle and operation of the platform,and we validate its performance by culturing cells and microtissues of a variety of different origins.Cells and tissues could be monitored on chip via high-resolution microscopy,while cell suspensions and microtissues could be easily retrieved for off-chip analysis.Our results demonstrate that primary immune cells and a range of different spheroid models of healthy and diseased tissues can be maintained for over 6 days on chip.As proof-of-concept cell-tissue interaction assay,we used an antibody treatment against diffuse midline glioma,a highly aggressive pediatric tumor.We are confident that our platform will help to increase the prediction power of in vitro preclinical testing of novel therapeutics that rely on the interaction of circulating cells with organ tissues.
基金National Natural Science Foundation of China (10475003, 10435010, 10705014, 10575036)Major State BasicResearch Development Program of China (2007CB815000)Knowledge Innovation Project of Chinese Academy of Sciences(KJCX3-SYW-N02, KJCX2-SW-N17)
文摘α decay energies of 323 heavy nuclei with Z ≥82 are evaluated with a macroscopic-microscopic model. In this model, the macroscopic part is treated by the continuous medium model and the microscopic part consists of shell and pairing corrections based on the Nilsson potential. α decay half-lives are calculated bY Viola-Seaborg formula. The results of α decay energies and half-lives are compared with experimental values and satisfactory agreement is found. The recoiling effect of the daughter nucleus on α decay half-life is also discussed.
