Spectra of Hydrogenic Donor States in Quantum-Dot Quantum Well Structures

The series expansion approach has been employed to calculate the exact energy spectra of hydrogenic donor states in a quantum-dot quantum well(QDQW). The result shows that the hydrogenic donor energy levels are very different from those in a quantum dot. In a QDQW, the donor energy levels depend on not only the radius of core and the barrier, but also the numbers of small wells. When there exist two small wells outside the core, the “band gap”exists between donor levels, and its width depends on the depth of the small wells.

料液比对加热回流法提取全叶千里光活性物质的影响

分别采用5种不同料液比提取全叶千里光活性物质,全谱波长扫描确定最佳波长。结果表明,1∶16时加热回流法提取全叶千里光活性物质含量最高,其最佳波长为416 nm,为全叶千里光活性物质的利用与开发奠定基础。