The present study was conducted to explore ways of JIVET research on Texel sheep,and to provide technical support for the improvement of the JIVET technology system for research on Texel sheep.Superovulation was condu...The present study was conducted to explore ways of JIVET research on Texel sheep,and to provide technical support for the improvement of the JIVET technology system for research on Texel sheep.Superovulation was conducted on 4-8-week old Texel sheep,and in-vivo ovum collection,in-vitro oocyte maturation and fertilization,and fertilized-embryo culture and transplantation were adopted to perform JIVET research on Texel sheep.The results showed that 296 available oocytes were obtained at an average of 74 oocytes per sheep;205 fertilized eggs were obtained at the 2-4 cell stage at an average of 51.25 eggs per sheep and a cleavage rate of 69.26%;and 66 of the fertilized eggs were transplanted to 11 receptor sheep.Six sheep were conceived at a conception rate of 54.55%,and 11 lambs were born.These results indicated that the present test could be used as a method for the study of JIVET technique on Texel sheep.展开更多
A series of new Cr-Mn-Fe-V-Cu high-entropy alloys were prepared by arc melting and suction casting.It is found that with the addition of Cu, the structure of the alloys evolved from BCC ＋ BCC1 phases to BCC ＋ FCC ph...A series of new Cr-Mn-Fe-V-Cu high-entropy alloys were prepared by arc melting and suction casting.It is found that with the addition of Cu, the structure of the alloys evolved from BCC ＋ BCC1 phases to BCC ＋ FCC phases. With increase of Cu, the volume fraction of the Cu-Mn-rich FCC phase increased, and the morphology of the FCC phase transformed from granular particles to long strips and blocks. Compared with other reported HEAs, the Cr-Mn-Fe-V-Cu HEAs exhibit a good balance between strength and ductility. The CrMn0.3 FeVCu0.06 alloy with granular FCC particles exhibits the highest compressive yield strength（1273 MPa） and excellent ductility（εf= 50.7%）. Quantitative calculations for different strengthening mechanisms demonstrate that dislocation and precipitate strengthening are responsible for high strength of the CrMn0.3 FeVCu0.06 alloy, while the solid solution strengthening effect is very low because of its small atomic-size difference. In addition, the CrMn0.3 FeVCu0.06 alloy exhibits good damping capacity due to its high dislocation and interface damping effects. Therefore, the dislocation density and distribution of FCC phase are the crucial factors for improvement of both mechanical properties and damping capacity of the HEAs.展开更多
基金the Science and Technology Project of Shanxi Province(20120311024-1)Special Fund for the Construction of National Wool Sheep Industrial Technology Research System(CARS-39-24)+1 种基金Shanxi Provincial Science and Technology Innovation Team Fund(201705D131028-20)Shanxi Financial Fund for Agriculture(NYGX2015-03)。
文摘The present study was conducted to explore ways of JIVET research on Texel sheep,and to provide technical support for the improvement of the JIVET technology system for research on Texel sheep.Superovulation was conducted on 4-8-week old Texel sheep,and in-vivo ovum collection,in-vitro oocyte maturation and fertilization,and fertilized-embryo culture and transplantation were adopted to perform JIVET research on Texel sheep.The results showed that 296 available oocytes were obtained at an average of 74 oocytes per sheep;205 fertilized eggs were obtained at the 2-4 cell stage at an average of 51.25 eggs per sheep and a cleavage rate of 69.26%;and 66 of the fertilized eggs were transplanted to 11 receptor sheep.Six sheep were conceived at a conception rate of 54.55%,and 11 lambs were born.These results indicated that the present test could be used as a method for the study of JIVET technique on Texel sheep.
基金support with testing materials and facilities from the Interdisciplinary Research Center for Advanced Structural and Biomaterials, Beihang University
文摘A series of new Cr-Mn-Fe-V-Cu high-entropy alloys were prepared by arc melting and suction casting.It is found that with the addition of Cu, the structure of the alloys evolved from BCC ＋ BCC1 phases to BCC ＋ FCC phases. With increase of Cu, the volume fraction of the Cu-Mn-rich FCC phase increased, and the morphology of the FCC phase transformed from granular particles to long strips and blocks. Compared with other reported HEAs, the Cr-Mn-Fe-V-Cu HEAs exhibit a good balance between strength and ductility. The CrMn0.3 FeVCu0.06 alloy with granular FCC particles exhibits the highest compressive yield strength（1273 MPa） and excellent ductility（εf= 50.7%）. Quantitative calculations for different strengthening mechanisms demonstrate that dislocation and precipitate strengthening are responsible for high strength of the CrMn0.3 FeVCu0.06 alloy, while the solid solution strengthening effect is very low because of its small atomic-size difference. In addition, the CrMn0.3 FeVCu0.06 alloy exhibits good damping capacity due to its high dislocation and interface damping effects. Therefore, the dislocation density and distribution of FCC phase are the crucial factors for improvement of both mechanical properties and damping capacity of the HEAs.
