有凝聚相玻色子系统格林函数的随机量子化

运用随机量子化方法,讨论了具有凝聚相的玻色子系统的格林函数.得到了带有反常格林函数的 Dyson 方程,并用矩阵形式下的 Langevin 方程得到了同一结果.     

黑洞能量涨落和黑洞视界邻近的辐射气温度上限

本文应用弯曲时空正则量子化方法,在1+1维情况下,证明了辐射气的温度分布函数为T(r)(gtt)^1/2=常数。进而讨论了1+1维Schwarzschild黑洞情况下黑洞能量的涨落现象,并由此估计了辐射场温度的上限。 关键词：     

自旋3/2场的随机量子化

本文选择了适当的核函数F(x,y),讨论了自旋3/2场的随机量子化. 得到了协变形式传播予, 并讨论了它与电磁场的相互作用.     

有限温度下介观L-C电路数-相量子涨落

借助于Weyl量子化方案,我们用数-相量子化观点讨论了有限温度下L-C回路的量子噪声,给出了噪声与温度T的函数关系,从数-相量子化方案还能给出相算符的具体形式及电路的振荡行为。     

约束系统量子化中Dirac方法与Faddeev-Jackiw方法的等价性

对约束系统量子化中Dirac方法和 Faddeev-Jackiw方法进行了讨论，并对它们的运动方程、正则量子化的等价性进行证明.找出了两种方法中约束的对应关系. 关键词： Faddeev-Jackiw方法 Dirac方法 约束系统 正则量子化     

一强耦合Toy Model β函数的单圈计算

本文利用背景场量子化方法对一具有SU(3)对称性的强耦合Toy Model的β函数进行了单圈计算.在低能情况下,β函数的极限与Appelquist-Carrazone定理相符.     

规范理论随机量子化的新方案

在规范理论随机量子化中，运用投影算子和函数δ（ｔ）构成的核，在零初值条件下，当ｔ趋于∞时，可以使之收敛于平衡态，并得到协变规范下的传播子。这样，规范理论和非规范理论的随机量子化方案即统一于只运用核函数。文中分别对麦克斯韦场、Ｃｈｅｒｎ－Ｓｉｍｏｎ场及线性引力理论进行了讨论。另外，还证明了上述形式的核不会对平衡分布产生影响。 关键词：     

STM中量子点接触的电导计算

采用模式匹配和散射矩阵方法，对扫描隧道显微镜(STM)中量子点接触过程中的电导进行了计算.结果表明由量子点接触形成的纳米结构的电导呈现量子化特征，这种量子化现象随所形成的纳米结构的横向尺寸和锥角的减小而增强.而且在半导体材料中比金属中更易观察到电导量子化现象. 关键词： STM 量子点接触 量子化电导     

组合Bose场的分数自旋和分数统计性

对组合Bose子场，采用FS (Faddeev-Senjanovic) 路径积分量子化方法进行量子化.从量子Noether定理出发，给出量子分数自旋和分数统计性质. 关键词： 路径积分量子化 分数自旋 分数统计     

等离子体/色散吸收介质界面系统中光场量子起伏功率谱

利用格林函数方法量子化色散吸收介质中的电磁场,研究了等离子体/色散吸收介质系统光场的量子性质.理论和数值计算表明,系统的工作状态与所选光场频率密切相关,等离子体介质的阻尼性明显地影响自身区域电场量子起伏功率谱,并且对另一侧介质中电场量子起伏功率谱的变化有连带作用.     

Coexistent effects in quantum mechanics

Effects are defined in this paper as observable changes in the state of a macrosystem, which are caused by interaction with a microsystem. These effects are the starting point of Ludwig's axiomatic foundation of quantum theory. In this theory the concept of commensurability is developed by considering effects which can be caused together, by one single microsystem. Such effects are called coexistent. It is shown that in ordinary quantum mechanics the formal definition of coexistence and the corresponding postulates given by Ludwig are consistent with the dynamics of interaction processes leading to effects.Part of a work supported by the Deutsche Forschungsgemeinschaft.     

两自由度带电耦合振子系统的守恒量与近似解

由于两自由度带电耦合振子系统的Lagrange函数中存在耦合项,从而导致其运动微分方程是非线性耦合的.先通过坐标变换消去Lagrange函数中的耦合项,用直接积分法求得系统的守恒量,用Adomian分解法求得系统的近似解,再通过坐标反变换求得系统在原坐标下的守恒量与近似解,并对近似解作了讨论.     

Single-mode optical waveguides fabricated in LiNbO3 by multienergy C implantations

Single-mode waveguides in LiNbO₃ are demonstrated by use of prism coupling method. The waveguides are fabricated by three different energies and single energy C²⁺ implantations at the equal total doses, respectively. Dark modes and propagation loss are measured by use of prism coupling and moving fiber methods, respectively. Damages produced by implantation are measured by RBS/channeling technique. The waveguide structures are investigated in two different implantation cases. The results of analysis indicate that the heavy ion-implanted waveguides are still defined by synergetic characteristics from both the raised-index region and the low-index barrier. The broadened barrier from multienergy implantation is demonstrated to play a significant role in reducing propagation loss.     

Strength distributions and statistical spectroscopy. I. General theory

The strength distribution for an arbitrary excitation is given in terms of a double expansion, and its sum rules by single expansions, in polynomials defined by the initial and final energy spectra. In model spaces which are not too large, a rapid convergence, to within fluctuations, is assured by the action of a central limit theorem, as is shown in particular by considering the response of the system under infinitesimal deformations of the Hamiltonian. When larger spaces are decomposed into subspaces defined by a partitioning of the single-particle space a similar convergence results. At the same time, close contact is made with, and important corrections are found to, intuitive procedures which are often used for approximating strength distributions. The general features of the distribution are often easily understood in termsof a simple geometry made effective in the model space by the central limit theorem, and further features by exploiting the connection of this geometry to the unitary group of transformations in the single-particle space. Extensions are given for multipole strengths and sum rules, appropriate when the angular momenta (and isospins) are specified for the states involved in the transitions. Measures for the RMS fluctuations in the sum-rule quantities, and correlations between them, are given by combining the low-order-polynomial (statistically smoothed) strengths with an assumed Porter-Thomas distribution for the (high-order) strength fluctuations.     

Surface electron states produced by a Rayleigh wave

The electronic properties of a semiconductor bounded by an uneven surface representing an infinitely high potential barrier are investigated. The surface irregularities are produced by a Rayleigh acoustic wave. It is shown that, on the boundary of a semiconductor, surface electron states (waves) may arise whose dispersion laws are obtained under the conditions when conduction electrons are located either in or outside the field of the acoustic wave. Existence domains of surface electron states are found that are distinguished by their physical properties. These domains are separated by a band gap whose width is determined by the height of irregularities.     

Analysis of the spatio-temporal scales of laminar premixed flames near equilibrium

The interplay between chemistry and transport is addressed by exploring the coupling between the spatial and temporal scales of one-dimensional laminar premixed combustion in reactive mixtures described by detailed chemical kinetics and multicomponent transport. System dynamics are investigated in the neighbourhood of the equilibrium state; in so doing, the time scales associated with modes of varying wavelength for the complete unsteady, spatially inhomogeneous system are obtained. The results reveal that short wavelength modes are dominated by diffusion-based time scales, and long wavelength modes are dominated by reaction-based time scales. The analysis further identifies critical wavelengths where the effects of reaction and diffusion are balanced, and it is seen that the critical wavelengths are well estimated by classical diffusion theory.     

Defects with deep levels induced by plastic deformation and electron irradiation in El2-free GaAs

Abstract

Defects with deep electronic energy levels induced by electron irradiation at room temperature or plastic deformation at 450°C in GaAs in which grown-in EL2 defects are previously eliminated by heat-treatment are investigated by means of measurements of the optical absorption and the Hall effect. Thermal stabilities of the induced defects are studied by tracing the changes mainly in the absorption specturm due to isochronal annealing. The absorptions both in deformed and irradiated specimens are mostly photo-unquenchable. Therefore, the defects induced by above two procedures are identified not to be EL2. Semi-insulating or n-type specimens convert to p-type by plastic deformation or electron irradiation, showing that high densities of acceptors are generated by the above two procedures.     

单波驱动的过渡粒子效应

本文讨论单波在环等离子体中引起的过渡粒子及其有关效应。 关键词：     

Scattering and propagation of terahertz pulses in random soot aggregate systems

Scattering and propagation of terahertz pulses in random soot aggregate systems are studied by using the generalized multi-particle Mie-solution(GMM) and the pulse propagation theory. Soot aggregates are obtained by the diffusion-limited aggregation(DLA) model. For a soot aggregate in soot aggregate systems, scattering characteristics are analyzed by using the GMM. Scattering intensities versus scattering angles are given. The effects of different positions of the aggregate on the scattering intensities, scattering cross sections, extinction cross sections, and absorption cross sections are computed and compared. Based on pulse propagation in random media, the transmission of terahertz pulses in random soot aggregate systems is determined by the two-frequency mutual coherence function. Numerical simulations and analysis are given for terahertz pulses(0.7956 THz).