The internal conversion processes of chlorophyll a in solvents are studied based on the reduced density matrix theory.
采用约化密度矩阵理论研究了溶液中叶绿素a分子的内转换过程。
Research papers in the temperature of 45 ℃ conditions, low pressure, low permeability, easy loss cementing formation of high-strength low-density required for the preparation of oil well cement program, the use of closest packing theory, the nucleation theory techniques to study the cement matrix, reduce the material, the cement admixture of the three aspects of high-strength low-density properties of oil well cement, indoor study of the system.
论文研究了在温度为45℃条件下，低压、低渗透、易漏失地层固井所需要的高强低密度油井水泥的配制方案，利用紧密堆积理论、晶核理论等技术，考察了水泥基材、减轻材料、水泥外加剂三个方面对高强低密度油井水泥性能的影响，对该体系进行室内研究。
Laser theory; Laser Pumping; pumping source; Atomic energy level; Density matrix
激光理论；激光抽运；抽运源；原了能级；密度矩阵
The key components in laser gyro is He-Ne ring laser, and the reciprocal action theory between light and medium is the base in studying the ring laser, use the Lamb half classical theory, and on the base of density matrix theory, the optical Brounch equation was established, which described the movement of amplifying medium atom in the ring syntonic cavity, and according to the medium polarize theory the self consistent equations was deduced, which describe the light intensity and phasic of the counter-propagating wave. On the basis of this equations, adopted the simulation software MATLAB and virtual instrument programming language LabWindows/CVI, we can do some simulated experiments in study the phenomenas such as amplify and dispersive characteristic of medium, mode pushing effection, burned hole effection and pattern competition, lock-in of frequency and the characteristic of light intensity and phasic of the counter-propagating wave in laser gyro.
激光陀螺的核心部件为He-Ne环形激光器，而掌握光与介质的相互作用理论是研究激光器的关键，采用拉姆半经典理论为主，在密度矩阵理论的基础上，推导环形谐振腔中描述He-Ne气体增益介质原子运动的光学布洛赫方程，运用介质极化理论得出描述激光陀螺反向行波的光强、位相所满足的自洽场方程组，在此基础上，运用MATLAB仿真软件和虚拟仪器编程语言LabWindows/CVI，对激光陀螺中的介质增益色散特性、频率牵引效应、烧孔效应及模竞争、闭锁效应及环激光的光强和相位特性进行仿真试验研究，并且运用全量子理论，对激光工作原理进行分析，得出二能级系统单模辐射场的光子数密度分布，得出激光场的光子统计分布，仿真激光场的动态建立过程。
The microscopic expressions of nonlinear susceptibility, nonlinear absorption coefficient andnonlinear refraction indices are detived from density matrix theory and a multi-energy-level model, All of them are proportional to the linear sum of the population in each energy-level, and amicroscopic expression of refraction volume describing nonlinear refraction is also derived.
本文从描述光与多能级分子系统相互作用的密度矩阵理论出发，得到非线性极化率，非线性折射率和非线性吸收系数的微观表达式，这三种非线性系数均正比于各能级的分子布居数，同时首次给出了描述非线性折射的折射体积的微观表达式。
The physical mechanism of the quantum coherent control photocurrent has been analyzed based on density matrix perturbation theory.
用密度矩阵微扰论研究了量子相干控制光电流的物理机制，说明它来源于密度矩阵对角元的实跃迁；
Using semiclassical theory, then we derive the Hamiltonian, probability amplitude, as well as the density matrix equation both in the two-level and the three-level atomic system, respectively.
接着，利用光与物质相互作用的半经典理论，分别推导了二能级原子系统和三能级原子系统中原子的哈密顿量、几率振幅以及密度矩阵方程。
The derived formulas on gain and saturation effect, dispersion and frequency pulling of the laser material agree with the results obtained by the third order approximation of the non-diagonal element of density matrix in Lamb's semi-classical theory and this method simplifies the mathematical processes.
所得到的激光物质的增益和饱和效应、色散和频率牵引的理论公式与兰姆半经典理论中，密度矩阵非对角元的三阶解理论结果完全一致。但这一方法简化了数学过程。
In theory, firstly introduce the theory which based on the semi-classical density matrix equations, the gain coefficients of infrared pumping signal and THz wave laser signal for a three-energy-level system were deduced.
理论研究方面，介绍了在三能级近似下，从半经典理论出发，由密度矩阵运动方程和电场的波动方程，求出太赫兹激光的增益系数和泵浦光的吸收系数方程的过程。
The main results are presented as follows: 1. Starting from the equation of motion in the density matrix formulation, we reformulate the analytical gradient of the excited-state energy at the time-dependent density functional theory level in the nonorthogonal Gaussian atom-centered orbital (AO) basis.
其中，主要的研究成果如下：1.从密度矩阵形式的运动方程出发，在非正交的Gaussian原子轨道基函数下发展了基于含时密度泛函理论的解析的激发态能量一阶导数的方法。
Change the concentration of rare earth ions and adjust glass matrix. Testing density, refractive index, absorption spectra, fluorescence spectra of glass; Using J-O theory, calculation the J-O intensity parameters, fluorescence branching ratio, fluorescence lifetime of glass.
改变掺杂稀土离子浓度和调整玻璃基质，测试玻璃的密度、折射率、吸收光谱、荧光光谱；运用J-O理论，计算玻璃的J-O强度参数、荧光分支比、荧光寿命。
In this chapter, we mainly give some basic theory of absorption, dispersion, dipole approximation and the equation of density matrix elements.
主要介绍激光光谱学的吸收和色散等基本概念以及常用的理论如偶极近似、密度矩阵方程等。
The main contents and conclusions are as follows: 1. The interband spectra in a QW driven by a THz field are investigated within the theory of density matrix.
用密度矩阵理论研究了太赫兹场作用下量子阱的光吸收谱。
Yamamoto also researched the thermodynamic properties of ferrimagnetic spin chain by modified spin wave theory and density-matrix renormalization-group method.
Yamamoto用修正的自旋波理论和密度矩阵重整化理论去研究海森堡亚铁磁链的热力学性质。
Description of Molecular Ultrafast Dynamics Process Using the Density Matrix Theory
分子超快动力学过程的密度矩阵理论描述
Using the density matrix theory describes the absorption and dispersion properties of the detecting light.
用密度矩阵理论描述了系统对探测光的吸收和色散性质。
Its fundamental formulae and existent conditions have been deduced using the density matrix theory with a two-level model and time-reversal arguments.
用密度矩阵理论、双能级模型和时间反演对称性推导了LICD的基本公式和存在条件。
Secondly, we also theoretically study the slow light in the double quantum dots Y-shape level structure by the density matrix theory.
另外，我们还通过密度矩阵理论理论研究了双量子点中Y型能级结构中的慢光。
By employing density matrix method and perturbation theory, the intra - and inter-band absorption properties have been investigated qualitatively and quantitatively.
本学位论文利用微扰理论和密度矩阵等方法研究了量子阱带内和带间的光吸收特性。
In some cases, however, the quantitatively ac-curate results necessitate the density matrix theory and the semiclassical model.
但在一些场合下，取半经典和密度矩阵模型对进行定量的计算是十分必要的。