佐治亚理工学院（Georgia Institute of Technology）与法国国家科学研究中心（Centre National de la Recherche Scientifique，CNRS）的研究人员协作，采用石墨薄片，即所谓的“二维碳原子薄片”，制作出晶体管、环形器件和电路，目...佐治亚理工学院（Georgia Institute of Technology）与法国国家科学研究中心（Centre National de la Recherche Scientifique，CNRS）的研究人员协作，采用石墨薄片，即所谓的“二维碳原子薄片”，制作出晶体管、环形器件和电路，目前还处于原理验证阶段。研究者们最终希望使这种厚度小于10个原子的二维碳原子薄片成为电子系统创新技术的基础，把电子作为电子波而不是粒子进行控制，就像光子系统控制光波一样。佐治亚理工学院物理分校的Walt de Heer教授说：“我们希望制作一种与硅基电子器件截然不同的器件，因此这是一种全新的电子器件制作方式。”“我们的最终目标是采用电子衍射技术而不是电子扩散技术，获得集成电子结构。采用这种方法可以制作具有极高效率和极低功耗的极小型器件。”展开更多
对七道次异步叠轧铜板采用220℃×30 m in和220℃×40 m in两种工艺进行退火,运用背散射电子衍射技术对两种铜板的再结晶程度、织构和晶界特征分布进行了研究。结果表明,经220℃×40 m in退火处理后,铜板的再结晶较完全,其...对七道次异步叠轧铜板采用220℃×30 m in和220℃×40 m in两种工艺进行退火,运用背散射电子衍射技术对两种铜板的再结晶程度、织构和晶界特征分布进行了研究。结果表明,经220℃×40 m in退火处理后,铜板的再结晶较完全,其织构为明显的{100}〈001〉立方织构;而经220℃×30 m in退火处理后,铜板内仍存在晶体缺陷,其织构为{123}〈412〉轧制织构及少量的{100}〈001〉立方织构。晶界特征分布图表明晶界都主要分布在Σ1、Σ3、Σ7、Σ9和Σ11位置上,采用220℃×40 m in退火处理后铜板中各主要晶界的含量明显高于采用220℃×30m in退火后的。展开更多
The crystalline syndiotactic 1,2-polybutadiene was synthesized with a catalytic system consisting of iron acetylacetonate , triisobutylaluminum and diethyl phosphite (DEP), and its single crystal structure was studied...The crystalline syndiotactic 1,2-polybutadiene was synthesized with a catalytic system consisting of iron acetylacetonate , triisobutylaluminum and diethyl phosphite (DEP), and its single crystal structure was studied by transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The polymer with melting point 179 ℃ was found to have 89.3% 1,2 content and 86.5% sydiotacticity based on 13C NMR measurement. The single crystals of the polymer were achieved by melt crystallization of the solution cast thin films at 150 ℃ for 2 h. Bright field electron micrograph shows that the single crystal exhibits a hexagonal prism shape with its long axis along the crystallographic b-axis, as revealed by the corresponding ED pattern. The strong (hk 0) reflections of the ED pattern indicate that the single crystal possesses a very good crystallographic orientation with the c-axis perpendicular to the film plane. According to the orthorhombic packing of the planar zigzag chains, all of the diffraction points can be indexed, and the unit cell parameters calculated from the ED result are a=1.102 nm and b=0.664 nm. In order to obtain the unit cell parameter c, α highly oriented thin film of the polymer was prepared with a special melt drawn technique. The TEM bright field image indicates that the melt drawn thin films contain highly oriented lamellae with their growing direction perpendicular to the drawing direction. The corresponding ED pattern reveals the molecular chains are highly oriented, with the c-axis parallel to the drawing direction. The unit cell parameter c is 0.513 nm, as calculated from the (hk 0) reflections.展开更多
文摘佐治亚理工学院（Georgia Institute of Technology）与法国国家科学研究中心（Centre National de la Recherche Scientifique，CNRS）的研究人员协作，采用石墨薄片，即所谓的“二维碳原子薄片”，制作出晶体管、环形器件和电路，目前还处于原理验证阶段。研究者们最终希望使这种厚度小于10个原子的二维碳原子薄片成为电子系统创新技术的基础，把电子作为电子波而不是粒子进行控制，就像光子系统控制光波一样。佐治亚理工学院物理分校的Walt de Heer教授说：“我们希望制作一种与硅基电子器件截然不同的器件，因此这是一种全新的电子器件制作方式。”“我们的最终目标是采用电子衍射技术而不是电子扩散技术，获得集成电子结构。采用这种方法可以制作具有极高效率和极低功耗的极小型器件。”
文摘对七道次异步叠轧铜板采用220℃×30 m in和220℃×40 m in两种工艺进行退火,运用背散射电子衍射技术对两种铜板的再结晶程度、织构和晶界特征分布进行了研究。结果表明,经220℃×40 m in退火处理后,铜板的再结晶较完全,其织构为明显的{100}〈001〉立方织构;而经220℃×30 m in退火处理后,铜板内仍存在晶体缺陷,其织构为{123}〈412〉轧制织构及少量的{100}〈001〉立方织构。晶界特征分布图表明晶界都主要分布在Σ1、Σ3、Σ7、Σ9和Σ11位置上,采用220℃×40 m in退火处理后铜板中各主要晶界的含量明显高于采用220℃×30m in退火后的。
文摘The crystalline syndiotactic 1,2-polybutadiene was synthesized with a catalytic system consisting of iron acetylacetonate , triisobutylaluminum and diethyl phosphite (DEP), and its single crystal structure was studied by transmission electron microscopy (TEM) and electron diffraction (ED) techniques. The polymer with melting point 179 ℃ was found to have 89.3% 1,2 content and 86.5% sydiotacticity based on 13C NMR measurement. The single crystals of the polymer were achieved by melt crystallization of the solution cast thin films at 150 ℃ for 2 h. Bright field electron micrograph shows that the single crystal exhibits a hexagonal prism shape with its long axis along the crystallographic b-axis, as revealed by the corresponding ED pattern. The strong (hk 0) reflections of the ED pattern indicate that the single crystal possesses a very good crystallographic orientation with the c-axis perpendicular to the film plane. According to the orthorhombic packing of the planar zigzag chains, all of the diffraction points can be indexed, and the unit cell parameters calculated from the ED result are a=1.102 nm and b=0.664 nm. In order to obtain the unit cell parameter c, α highly oriented thin film of the polymer was prepared with a special melt drawn technique. The TEM bright field image indicates that the melt drawn thin films contain highly oriented lamellae with their growing direction perpendicular to the drawing direction. The corresponding ED pattern reveals the molecular chains are highly oriented, with the c-axis parallel to the drawing direction. The unit cell parameter c is 0.513 nm, as calculated from the (hk 0) reflections.
