依赖强度与时间耦合场-原子系统中场熵演化

利用Von Neumann量子约化熵理论,研究了共振情况下场与原子之间的耦合随时间和强度变化时,A型三能级原子与单模场相互作用系统中量子场熵的演化特性,通过数值计算详细讨论了不同初始光场和耦合系数变化的快慢对量子场熵的影响。结果表明:初始光场统计性质的不同将使系统的量子场熵演化发生较大变化,耦合强度调制函数的变化将改变量子场熵演化曲线的振荡频率,场与原子相互作用的初始阶段是一个逐渐耦合的过程,原子叠加态概率使量子场熵周期性地发生改变。

狮45井KQ78-65-140FF井口装置酸化压裂失效分析与对策

KQ78-65-140FF是青海油田的第一套千型井口装置,为油田各类大型压裂酸化的成功实施起到了积极的推动作用。本文针对该井口装置在狮45井酸化压裂施工过程中总阀压盖渗漏、安全阀失效等问题,通过现场解体检查、分析,找到造成本次酸化压裂失效的原因,并制定出相应的对策,提出井口装置使用长效监测机制,确定试压次数与使用次数对井口装置疲劳损伤的课题研究方向,确保井口装置在油田勘探开发大型压裂酸化过程中的保障作用。

理工专业课程的多元化教学实践分析

基于理工类专业课程与人文社科类课程相比的特点,阐述课程的多元化教学实践,探讨教学目标、教学大纲、教学设计的教学方法。

量子力学课程的教学实践

结合西安工业大学的量子力学课程改革经验,阐述坚持以学生为主,以教师为引导,从教师引导、评价方式等方面提出几点思考,从而为有效推进课程改革,提出对策建议。

Evolution of the field quantum entropy and entanglement in a system of multimode light field interacting resonantly with a two-level atom through N_j-degenerate N~Σ-photon process

The time evolution of the field quantum entropy and entanglement in a system of multi-mode coherent light field resonantly interacting with a two-level atom by de-generating the multi-photon process is studied by utilizing the Von Neumann re-duced entropy theory,and the analytical expressions of the quantum entropy of the multimode field and the numerical calculation results for three-mode field inter-acting with the atom are obtained. Our attention focuses on the discussion of the influences of the initial average photon number,the atomic distribution angle and the phase angle of the atom dipole on the evolution of the quantum field entropy and entanglement. The results obtained from the numerical calculation indicate that: the stronger the quantum field is,the weaker the entanglement between the quan-tum field and the atom will be,and when the field is strong enough,the two sub-systems may be in a disentangled state all the time; the quantum field entropy is strongly dependent on the atomic distribution angle,namely,the quantum field and the two-level atom are always in the entangled state,and are nearly stable at maximum entanglement after a short time of vibration; the larger the atomic dis-tribution angle is,the shorter the time for the field quantum entropy to evolve its maximum value is; the phase angles of the atom dipole almost have no influences on the entanglement between the quantum field and the two-level atom. Entangled states or pure states based on these properties of the field quantum entropy can be prepared.

基于光自注入法的光纤激光器线宽优化

光纤激光器的线宽是反映激光雷达空间分辨率与激光精密测量系统测量精度的重要指标,在工程实践中具有重要的应用价值。基于线宽测量与光自注入反馈法的基本理论对比加入优化结构前后光纤激光器的线宽,并通过实验探究光自注入双腔反馈结构对光纤激光器线宽特性的优化作用。搭建复合环形光纤激光器与自注入双腔反馈线宽优化结构,并采用延迟自外差法对输出光的线宽进行测量。实验结果表明,光自注入双腔反馈结构可以将光纤激光器的平均线宽从1.782 kHz进一步压缩到1.319 kHz,实现更窄线宽的激光输出。