二项式光场与级联三能级原子的量子纠缠

利用量子熵理论，研究了二项式光场与级联三能级原子的量子纠缠，讨论了光场与原子的初始参量对其量子纠缠性质的影响.结果表明，利用二项式光场的特性，可以揭示从相干态到数态之间的所有态光场与三能级原子相互作用时的量子纠缠性质.选择适当的系统参数可以制备稳定的光场-原子qutrit纠缠态. 关键词： 二项式光场 级联三能级原子 光场熵 量子纠缠     

用自适应脉冲微扰引导混沌系统到周期解

用自适应脉冲微扰方法控制的系统的某个系统变量作为驱动,设计了一种自适应控制器方法对两个或多个响应混沌系统进行脉冲微扰,引导这些系统从混沌运动到低周期运动,实现同时控制多个混沌系统到不同的周期态. 当选择相同的自适应控制器输入变量实施脉冲微扰时,还可控制两个或多个混沌系统达到不同的周期态同步. 通过对R?ssler混沌系统的仿真研究证实了方法的有效性. 关键词： 混沌控制 系统参量 自适应控制器 脉冲微扰 周期态同步     

均苯三甲酸铕及铕镧配合物的合成及荧光性质

以均苯三甲酸为配体,水热条件下合成了均苯三甲酸铕及铕镧系列发光配合物La_xEu_1-x(BTC)·nH₂O(x=0,0.1,0.3,0.5,0.7,0.9),通过元素分析及化学滴定法测定了配合物的组成。用红外光谱对其进行了表征,确定了该系列配合物的组成为La_xEu_1-x(BTC)·nH₂O。研究了系列配合物的荧光性质,荧光光谱表明:该类配合物均能发出强的铕离子的特征荧光,并且镧元素的掺入能增强铕配合物的发光强度,但发射峰的位置基本上没有变化;其中⁵D₀→⁷F₁和⁵D₀→⁷F₂的跃迁发射较强,且均劈裂为两个峰(587,593nm)和(611,618nm),这是由于铕离子所处的配位环境引起的。     

T-型树谱唯一性的一个简单刻画

图G称为谱唯一的,如果任何与G谱相同的图一定与G同构.一棵树称为T-型树如果其仅有一个最大度为3的顶点.本文给出了T-型树谱唯一性的一个简单刻画,从而完全解决了T-型树的谱唯一性问题.     

Spectral line suppression and sideband narrowing via quantum interference

We reveal that for a realistic system, interference effects are obtained such as the suppression of central line and inner sidebands and the narrowing of the outer fluorescence sidebands. For this purpose, we consider a spontaneous decay from an excited state to a metastable state when the excited and metastable states are resonantly coupled to an auxiliary metastable state by a laser field and a microwave field, respectively. The fluorescence spectrum evolves from a five-peaked structure into a doublet of ultrasharp lines as the ratio of the laser field Rabi frequency to the microwave Rabi frequency is decreased. The physical origin is presented in terms of dressed states.     

Global and uniform convergence of subspace correction methods for some convex optimization problems

This paper gives some global and uniform convergence estimates for a class of subspace correction (based on space decomposition) iterative methods applied to some unconstrained convex optimization problems. Some multigrid and domain decomposition methods are also discussed as special examples for solving some nonlinear elliptic boundary value problems.

     

The study and applications of photochemical-dynamical gravity wave model II

A nonlinear, compressible, non-isothermal gravity wave model that involves photochemistry is used to study the effects of gravity wave on atmospheric chemical species distributions in this paper. The changes in the distributions of oxygen compound and hydrogen compound density induced by gravity wave propagation are simulated. The results indicate that when a gravity wave propagates through a mesopause region, even if it does not break, it can influence the background distributions of chemical species. The effect of gravity wave on chemical species at night is larger than in daytime.     

双纠缠原子在耗散腔场中的纠缠动力学

研究了能量损耗腔中,两纠缠二能级原子与单模辐射场相互作用过程中原子的纠缠动力学.结果表明:双纠缠原子的纠缠度演化特性决定于初始两原子间的纠缠度、纠缠形式、腔场的平均光数、腔场的衰变系数.当原子初始处于一特定纠缠态时,其纠缠度可以放大,并且不受腔场损耗的影响. 关键词： 二能级原子 纠缠度 密度算符 单模辐射场     

两种方法制备ITO薄膜的红外特性分析

比较了用电束加热蒸发法和直流磁控溅射法制备的氧化锡铟(ITO)薄膜在红外波段的光学特性实验发现,通过直流磁控溅射在常温下制备的ITO薄膜在红外波段折射率稳定、消光系数小,比电子束加热蒸发制备的膜有较高的透过率在波长1550nm附近的透过率可达86%以上,消光系数约为004,方电阻最低为100Ω/□.     

Soliton interaction under the influence of higher-order effects

In this paper, we present exact N-soliton solution by employing simple, straightforward Darboux transformation based on the Lax pair for Hirota equation, a higher-order nonlinear Schrödinger (HNLS) equation. As examples, one- and two-soliton solutions in explicit forms are given and their properties are also analyzed. A bound solution without interaction will be theoretically predicted if one can adjust frequency shift for each soliton appropriately. Further, we obtain the approximate eigenvalues by employing two-soliton solution and discuss analytically the interaction between neighboring solitons under the influence of the higher-order effects. It is shown that the combined effects of the higher-order effects can restrain the interaction between neighboring solitons to some extent. The results are proved by directly solving HNLS equation numerically.