Dynamical Behavior of an Atomic Beam Interacting with a Fock State Light Field

The collapse and revival of evolution with photon number of population inversion in the case of an atomic beam with velocity distribution interacting with a single-mode and Fock-state light field is investigated by full quantum theory. Compared to the previously reported coherent state case [Li B and Chen J B Chin. Phys. Lett. 26（2009）123203], which was induced by evolution with coupling strength of population inversion, in the case under consideration there exists Poisson distribution of photon numbers and atomic velocity distribution in the beam. Moreover, we prove that above, the collapse and revival have an analogy with conventional collapse and revival [Eberly J H et al. Phys. Rev. Lett. 44（1980）1323] in both the mathematical expression and physical significance.     

Quantum Phase Transition of the Bosonic Atoms near the Feshbach Resonance in an Optical Lattice

The quantum phase transition from the Mott insulator to the superfluid phases of the bosonic atoms trapped in an optical lattice, in which the on-site interaction carl be tuned by a Feshbach resonance, is investigated by a variational approach within mean-field theory. We derive an extended Bos~Hubbard model to describe this ultracold atomic system. By theoretical calculation and analysis, the phase diagram is shown clearly, and we find an exciting and novel phenomenon that is the appearance of the Mort insulator-sea （MI-sea）. Meanwhile, the experimental feasibility of observing the MI-sea is discussed by analyzing the published data related to the Fashbaeh resonance at present. Finally, the potential application of the MI-sea for quantum information processing and quantum computation is also discussed in detail     

Collapse and Revival of an Atomic Beam Interacting with a Coherent State Light Field

We report on the phenomena of the periodic spontaneous collapse and revival in the dynamics of an atomic beam interacting with a single-mode and coherent-state light field. Conventional collapse and revival by Eberly et al. [Phys. Rev. Lett. 44（1980）1323 ] are presented in the case of the evolution with time of the population inversion. Here, we study the evolution with coupling strength of population inversion. We define the collapse and revival coupling strengths as characteristic parameters to describe the above collapse and revival. Furthermore, we present the analytic formulas for the population inversion, the collapse and revival coupling strengths.     

在线超临界流体色谱联用技术测定超临界二氧化碳中芘溶解度

设计了一种单阀外循环接口,采用静态溶解度测定方法,联用在线超临界流体色谱,准确测定了芘在超临界二氧化碳中的溶解度.通过釜内磁力搅拌和接口外循环的双重作用,促进芘在超临界二氧化碳中的溶解平衡过程,确保在测定芘溶解度时体系已达到溶解平衡状态,确定了溶解平衡时间,消除了联用体系中因芘的溶解度过高而产生的体系堵塞问题.     

在线超临界色谱联用接口装置的研制与应用

建立了动态和静态接口装置,使其能在线联用超临界色谱确定蒽在超临界二氧化碳中的溶解度及溶解平衡过程。静态接口由2个高压阀组成,动态接口由1个高压阀和1个齿轮泵组成。采用静态法测定蒽在超临界二氧化碳中的溶解度,以考察温度和压力对溶解度的影响。实验结果表明,在40~60℃和10~27.5MPa条件下,自行研制的在线超临界色谱联用体系具有较高的稳定性和较好的重现性,溶解度的相对标准偏差(RSD)为0.4%~2.4%,准确性为95.0%~97.7%。采用Méndez-Santiago Teja(MST)模型公式对实验数值关联计算,确定了蒽的溶解度与二氧化碳密度的准线性函数变化关系,计算数值与实验结果之间的相对平均绝对值偏差(AARD)为3.23和14.68。搭建的接口装置亦能够完成超临界流体技术与常规光谱、质谱分析仪器的在线联用分析,在药物合成与分析、过程分析技术(PAT)等领域具有较好的应用潜力。