胸腰段爆裂骨折的CT表现及临床意义

目的：通过观察胸腰段爆裂骨折的ＣＴ表现，探讨其治疗方法。方法：回顾性分析６４例胸腰椎爆裂骨折，研究其ＣＴ表现。结果：胸腰椎前、中、后三柱损伤３１例，前、中柱损伤２２例，中柱损伤１１例；无骨片进入椎管１２例，椎管内骨片占有百分比＜５０％为３６例，＞５０％为１６例。结论：ＣＴ能对椎管损伤准确诊断，对治疗方式的选择有重要参考价值。

Cross-Polarized Single Photon Emission from Single Semiconductor Quantum Dots with V-Type Level Driven by Pulse Field

The statistic properties of photon emissions from single semiconductor quantum dots with V-type leveldriven by pulses are investigated theoretically.Based on quantum regression theorem and master equations,the dynamicequations of the second-order correlation function of the photon emissions are deduced.The calculated results reveal thatthe efficiency of single photon emissions from two orthogonal polarization eigenstates(|x〉and |y〉)reaches the maximumwhen the input pulses area is about π,and the probability of the cross-polarized single photon emission from |x〉and |y〉decreases with increasing of pulse width.