All the spin relaxation mechanisms and the theoretical approaches are reviewed : For the two-level system the relaxation time can be calculated directly by the Fermi golden rule or the time evolution of the equation of motion .

紧接着我们回顾了导致自旋弛豫的各种机制以及理论上的处理方法。对于 简单 的 两 能级 系统，可以使用费米黄金规则和运动方程计算自旋弛豫／去相位时间。

Further more a detailed comparative study of two-level system and three-level system is conducted . The simulation results three-phase current waveforms the electromagnetic torque waveform are given .

并且与 两 电平 系统从三相电流波形、电磁转矩波形进行了详细的对比分析，分析发现 采用三电平变流器后，电流的谐波明显减少，更加接近正弦波，电磁转矩脉动得到改善。

Investigation of the evolution of fidelity of quantum information in many-photon two-level system

多光子 两 能级 系统量子信息保真度演化规律的研究

Population trapping phenomena in a two-level system

二 能级 系统的布居囚禁现象

In such dot-cavity systems exciton in quantum dots constitutes an alternate two-level system instead of the usual two-level atomic system and this is the study focus of this paper .

在这种量子点&微腔结构中，量子点中的激子产生了不同于通常原子的 二 能级 系统，而这种 二 能级系统就是本文研究的焦点。

By taking into account the light hole and heavy hole valence band structures and their combined density of states the expression of saturation absorption is deduced from the imaginary part of the susceptibility which is similar to the mode of inhomogeneous broadening of two-level system .

考虑了锗中轻、重空穴价带的能带结构并利用轻、重空穴价带的复合态密度，由电极化率的虚部推得类似于非均匀展宽 两 能级 系统模型的饱和吸收具有的形式。

The dynamical consequence of such a quantum phase transition is the decoherence suppression of the two-level system .

该量子相变的动力学后果是开放量子系统中的 二 能级 系统的退相干抑制。

Electromagnetically Induced Absorption of Degenerate Two-Level System in a Cesium Vapor Cell

铯原子气室中简并 二 能级 系统的电磁诱导吸收

Additionally the double-peak phenomenon appearing at the strong pump beam is well explained by dressing-state theory in the two-level system .

此外，在 二 能级 系统中引入缀饰态理论，很好地解释了强泵浦光引起的DFWM光谱中的双峰现象及其随泵浦光偏振状态的变化。

The critical criterion for realizing population trapping is deduced for a two-level system driven by a frequency-modulated laser field in terms of dressed atom model followed by demonstrating the various population trapping behaviours under different conditions .

采用缀饰原子模型，以解析方式研究了 二 能级 系统布居囚禁现象，给出了实现布居囚禁现象的条件，并通过解析公式计算演示了各种条件下布居囚禁的不同行为。

The corresponding area theorem is derived which is a generalization of the area theorem related initially to the light pulse propagation through the two-level system .

导出了相应的“面积定理”，是将只关系到光脉冲在 二 能级 系统中传播的面积定理的一种推广。

Dynamics of the Two-level System Coupled with Single Model Field Beyond the Rotating Wave Approximation

超越旋转波近似的单模 二 能级 系统动力学

In this paper the time-resolved degenerate four-wave mixing in two-level system is treated rigorously with the density-matrix method .

本文用密度矩阵方法严格处理了在共振情况下 二 能级 系统时间分辨简并四波混频问题。

Considering the fact that multiple switching from normal to anomalous dispersion at multiple frequency regimes has some potential uses in quantum computation and quantum information etc we explore mainly the dispersion switching properties of a two-level system driven by the trichromatic field .

考虑到正负色散在多个不同频率区域上的多重转换在量子计算和量子信息等方面有着潜在的应用，在本文中我们集中研究了三色激发 二 能级 系统的多重色散转换特性。

Population Oscillation of Upper Level Excited by Laser Pulses Pair in Two-Level System

脉冲对激发的上 能级布居振荡

It is shown that this ap-proach can not only treat the two-level system within the rotating wave approximation ( RWA ) but also present an exact solution of the JC model without RWA .

本文的结果表明：这种方法不仅能够处理在旋转波近似下的 二 能级 体系，也可以用来精确求解无旋转波近似时的JC模型。

Exact calculations of the energy spectra and the dynamical properties of a two-level system

精确计算非旋波近似下 二 能级 系统的能谱和动力学性质

Collaborative Optimization ( CO ) is a two-level system optimization method which has developed over the last decade . It has successfully developed and exclusively applied to the aeronautics and space industry but the application of CO to the complicated mechanical system just gets started .

协同优化是近十几年发展起来的一种 两 层 系统优化方法，在航空航天领域已得到长足发展和广泛应用，而在复杂工程机械系统领域的研究才刚刚起步。

It is the superconducting quantum interference device as two-level system approximately operating in a particular state .

超导量子比特是工作在特定条件而可以近似看作 二 能级 体系超导量子干涉仪。

In optical regime this molecule has only one charge-transfer state and the molecule can thus be simplified as a two-level system .

在光学范围内，该分子只有一个电荷转移态，因此分子可以简化为 两 能级 模型。

On the relaxation effect of Stark splitted levels for a two-level system interacting with a symmetrical strong resonant bichromatic field

对称强双色共振场中弛豫效应对 二 能级 系统斯塔克分裂的影响

The two-level system interacting with a single-mode boson is studied using the method of coherent approximation . We calculated the occupation probability P I ( t ) of the system and compare it with the results of Jaynes-Cummings model under different situations .

应用相干态近似方法研究了与单模玻色子耦合的 二 能级 系统，计算了该系统下的能量占有几率Pi（t），并且在各种不同的条件下与JaynesCummings模型计算出的结果进行了比较。

We show that the counter-rotating component leads to the Bloch-Siegert shift in a two-level system while leads to an asymmetry of the Autler-Townes doublet in a three-level system . The above results are explained via the dressed-state theory .

结果表明，在 双 能级 系统中反旋项主要引起Bloch-Siegert频移，在V-型三能级系统中反旋项将导致Autler-Townes双峰的不对称。

Based on the behavior of spectral hole burning of two-level system situations of persistent hole burning and photon gated spectral hole burning have also been considered .

以 二 能级 系统光谱烧孔为基础，讨论了永久性光谱烧孔和光子选通光谱烧孔中孔的行为。

A Probe into Deep-seated Issues of two-level System Reform in Russian Higher Education

俄罗斯高等教育 两 级 制改革的深层问题探析

Coherent propagation of optical pulses in a two-level system driven by an intense laser beam

强近共振激光驱动下 二 能级 系统中激光脉冲的相干传播

Based on the rate equations of two-level system the solutions of spin-up and spin-down carrier populations are obtained under the condition of incompletely initial spin polarization photoinduced by elliptically polarized pump light .

基于 二 能级 体系的速率方程，获得了椭圆偏振光泵浦注入非完全自旋极化初始条件下的自旋向上和向下载流子布居的解析解。