采用碳酸盐共沉淀-高温固相法制备了一系列表面碳包覆改性(w=1.0%,2.0%,3.0%)的LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料,借助X射线衍射(XRD)分析、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电流充放电测试等表征手段对材料...采用碳酸盐共沉淀-高温固相法制备了一系列表面碳包覆改性(w=1.0%,2.0%,3.0%)的LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料,借助X射线衍射(XRD)分析、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电流充放电测试等表征手段对材料的晶体结构、微观形貌和电化学性能进行了较系统的研究。结果表明,碳成功地包覆在了材料颗粒的表面,碳包覆改性后的材料具有良好的α-Na Fe O2结构(空间群:R3m),且随着包碳量的增加,一次颗粒平均尺寸逐渐增大(从177 nm增至209 nm)。表面的无定形碳层可以提高材料的电子导电率,减少电极材料与电解液的副反应,故而碳包覆材料的电化学性能都有了一定程度提升。包覆碳量为2.0%的样品高倍率和长循环性能最好,在2.7~4.3 V,1C下循环100次后,容量保持率为93%;在0.1C、0.2C、0.5C、1C、3C、5C、10C和20C时的放电比容量分别为:155、148、145、138、127、116、104和96 m Ah·g-1。在超高倍率50C(9 A·g-1)时,其放电比容量还能达到62 m Ah·g-1(原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料仅为30 m Ah·g-1),倍率性能十分优异。展开更多
To construct the eukaryot ic expression system of E1 glycopr otein of rubella virus(RV)JR23 str ain and to study the biological an d immunological properties of the expressed product,the E1 gene was amplified by RT-PC...To construct the eukaryot ic expression system of E1 glycopr otein of rubella virus(RV)JR23 str ain and to study the biological an d immunological properties of the expressed product,the E1 gene was amplified by RT-PCR,sequenced and recombinated with the pBluescript ⅡSK+ vectorThe recombinated vecto r was co-transfected into BHK21 ce ll with vaccinia virus which carri es the gene of T7 RNA polymeraseT he expressed protein was characteri zed with hemadsorption,immunohisto chemistry and indirect immunofluor escence stainingThe results showe d that the recombinated vector,pBS K+-RV E1,was proved containing E1 gene by enzyme digestion and seque ncingThe expressed protein could be detected both in cytoplasm amd on membrane of the transfected cel ls by hemadsorption,immunohistoche mistry and indirect immunofluoresc enceThe E1 protein mainly focused in cytoplasm near the nucleusThes e data proved that the expression vector,pBSK+-RV E1,was successfull y constructed and the glycoprotein E1 of RV JR23 strain was effective ly expressed in BHK21 cell culture This study provides foundations f or studies on the relationships be tween structure and function of RV gene,between structure and functio n of RV proteins,and on the subuni t vaccine of rubella展开更多
文摘采用碳酸盐共沉淀-高温固相法制备了一系列表面碳包覆改性(w=1.0%,2.0%,3.0%)的LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2正极材料,借助X射线衍射(XRD)分析、扫描电镜(SEM)、透射电镜(TEM)、电化学阻抗谱(EIS)和恒电流充放电测试等表征手段对材料的晶体结构、微观形貌和电化学性能进行了较系统的研究。结果表明,碳成功地包覆在了材料颗粒的表面,碳包覆改性后的材料具有良好的α-Na Fe O2结构(空间群:R3m),且随着包碳量的增加,一次颗粒平均尺寸逐渐增大(从177 nm增至209 nm)。表面的无定形碳层可以提高材料的电子导电率,减少电极材料与电解液的副反应,故而碳包覆材料的电化学性能都有了一定程度提升。包覆碳量为2.0%的样品高倍率和长循环性能最好,在2.7~4.3 V,1C下循环100次后,容量保持率为93%;在0.1C、0.2C、0.5C、1C、3C、5C、10C和20C时的放电比容量分别为:155、148、145、138、127、116、104和96 m Ah·g-1。在超高倍率50C(9 A·g-1)时,其放电比容量还能达到62 m Ah·g-1(原始LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2材料仅为30 m Ah·g-1),倍率性能十分优异。
文摘To construct the eukaryot ic expression system of E1 glycopr otein of rubella virus(RV)JR23 str ain and to study the biological an d immunological properties of the expressed product,the E1 gene was amplified by RT-PCR,sequenced and recombinated with the pBluescript ⅡSK+ vectorThe recombinated vecto r was co-transfected into BHK21 ce ll with vaccinia virus which carri es the gene of T7 RNA polymeraseT he expressed protein was characteri zed with hemadsorption,immunohisto chemistry and indirect immunofluor escence stainingThe results showe d that the recombinated vector,pBS K+-RV E1,was proved containing E1 gene by enzyme digestion and seque ncingThe expressed protein could be detected both in cytoplasm amd on membrane of the transfected cel ls by hemadsorption,immunohistoche mistry and indirect immunofluoresc enceThe E1 protein mainly focused in cytoplasm near the nucleusThes e data proved that the expression vector,pBSK+-RV E1,was successfull y constructed and the glycoprotein E1 of RV JR23 strain was effective ly expressed in BHK21 cell culture This study provides foundations f or studies on the relationships be tween structure and function of RV gene,between structure and functio n of RV proteins,and on the subuni t vaccine of rubella
