目的建立简便、灵敏的手性高效液相色谱法检查苄基依折麦布中的异构体杂质。方法以Chiralpak IC为固定相,正己烷-异丙醇（体积比90∶10）为流动相,流速为1.0 m L·min-1,检测波长为232 nm。结果通过对分离条件进行优化,苄基依折麦...目的建立简便、灵敏的手性高效液相色谱法检查苄基依折麦布中的异构体杂质。方法以Chiralpak IC为固定相,正己烷-异丙醇（体积比90∶10）为流动相,流速为1.0 m L·min-1,检测波长为232 nm。结果通过对分离条件进行优化,苄基依折麦布与其异构体杂质能达到良好分离。苄基依折麦布在质量浓度为1.0～12 mg·L-1内线性关系良好。平均回收率为99.8%,日内与日间精密度均小于3.0%。结论所建立的分析方法灵敏度高、重现性好,适用于苄基依折麦布中异构体杂质的检查。展开更多
With the use of variational method to solve the effective mass equation, we have studied the electronic and shallow impurity states in semiconductor heterostructures under an applied electric field. The electron energ...With the use of variational method to solve the effective mass equation, we have studied the electronic and shallow impurity states in semiconductor heterostructures under an applied electric field. The electron energy levels are calculated exactly and the impurity binding energies are calculated with the variational approach. It is found that the behaviors of electronic and shallow impurity states in heterostructures under an applied electric field are analogous to that of quantum wells. Our results show that with the increasing strength of electric field, the electron confinement energies increase, and the impurity binding energy increases also when the impurity is on the surface, while the impurity binding energy increases at first, to a peak value, then decreases to a value which is related to the impurity position when the impurity is away from the surface. In the absence of electric field, the result tends to the Levine's ground state energy (-1/4 effective Rydberg) when the impurity is on the surface, and the ground impurity binding energy tends to that in the bulk when the impurity is far away from the surface. The dependence of the impurity binding energy on the impurity position for different electric field is also discussed.展开更多
基金Natural Science Foundation of Shanghai Municipal Commission of Education
文摘With the use of variational method to solve the effective mass equation, we have studied the electronic and shallow impurity states in semiconductor heterostructures under an applied electric field. The electron energy levels are calculated exactly and the impurity binding energies are calculated with the variational approach. It is found that the behaviors of electronic and shallow impurity states in heterostructures under an applied electric field are analogous to that of quantum wells. Our results show that with the increasing strength of electric field, the electron confinement energies increase, and the impurity binding energy increases also when the impurity is on the surface, while the impurity binding energy increases at first, to a peak value, then decreases to a value which is related to the impurity position when the impurity is away from the surface. In the absence of electric field, the result tends to the Levine's ground state energy (-1/4 effective Rydberg) when the impurity is on the surface, and the ground impurity binding energy tends to that in the bulk when the impurity is far away from the surface. The dependence of the impurity binding energy on the impurity position for different electric field is also discussed.
