Mg-xLi-Al alloys with Mn addition from 0.2% to 1.5 % by wt. were produced and studied. The density of the alloys is very low, between 1.21 g/cm3 and 1.64 g/cm3, while the microstructures change from single α-, (α+β...Mg-xLi-Al alloys with Mn addition from 0.2% to 1.5 % by wt. were produced and studied. The density of the alloys is very low, between 1.21 g/cm3 and 1.64 g/cm3, while the microstructures change from single α-, (α+β)-, to single β-phase with lithium content rising from 5 % to 22 % by wt. The main alloy studied was LA92 alloy with Mn addition. The results of the tensile tests show that the strength decreases with increasing lithium content, while the elongation increases sharply, and the UTS and YS rise by 26.8% and 22.7% respectively, when 0.5 % by wt. Mn is added. It is also known, by microstructure observation, SEM with EDS and X-ray analysis, that adding Mn can produce some new hard phases in the alloy, which may worsen the tensile properties.展开更多
The 5＇-nontranslated leader（omega sequence） of Tobacco mosaic virus（TMV） was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen（HBsAg） gene in transgenic ginseng call...The 5＇-nontranslated leader（omega sequence） of Tobacco mosaic virus（TMV） was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen（HBsAg） gene in transgenic ginseng callus cultures. The adr subtype HBsAg gene was placed under the control of the Cauliflower mosaic virus（CaMV） 35S promoter linking to the TMV leader sequence. The antisense omega sequence was used in a control construct. The resulting constructs cloned in the binary vector pBI121 were used to transform the ginseng callus tissue via the Agrobacterium-mediated procedure. The integration and expression of the HBsAg gene were evaluated by PCR and western blot, respectively. Enzyme-linked immunoassays（ELISA） using a monoclonal antibody directed against human serum-derived HBsAg revealed a three to four-fold enhanced expression of HBsAg in ginseng cells conferred by the TMV omega element.展开更多
文摘Mg-xLi-Al alloys with Mn addition from 0.2% to 1.5 % by wt. were produced and studied. The density of the alloys is very low, between 1.21 g/cm3 and 1.64 g/cm3, while the microstructures change from single α-, (α+β)-, to single β-phase with lithium content rising from 5 % to 22 % by wt. The main alloy studied was LA92 alloy with Mn addition. The results of the tensile tests show that the strength decreases with increasing lithium content, while the elongation increases sharply, and the UTS and YS rise by 26.8% and 22.7% respectively, when 0.5 % by wt. Mn is added. It is also known, by microstructure observation, SEM with EDS and X-ray analysis, that adding Mn can produce some new hard phases in the alloy, which may worsen the tensile properties.
基金Science and Technology Development Planning Foundation of Jilin Province, China(No. 20030405)
文摘The 5＇-nontranslated leader（omega sequence） of Tobacco mosaic virus（TMV） was used as a translational enhancer sequence in the expression of the hepatitis B surface antigen（HBsAg） gene in transgenic ginseng callus cultures. The adr subtype HBsAg gene was placed under the control of the Cauliflower mosaic virus（CaMV） 35S promoter linking to the TMV leader sequence. The antisense omega sequence was used in a control construct. The resulting constructs cloned in the binary vector pBI121 were used to transform the ginseng callus tissue via the Agrobacterium-mediated procedure. The integration and expression of the HBsAg gene were evaluated by PCR and western blot, respectively. Enzyme-linked immunoassays（ELISA） using a monoclonal antibody directed against human serum-derived HBsAg revealed a three to four-fold enhanced expression of HBsAg in ginseng cells conferred by the TMV omega element.
