赝标介子的唯象模型(Ⅰ)

本文基于场论中的旋量-旋量Bethe-Salpeter方程(以下简称B-S方程),提出了一种满足相对论协变性要求的强子间的唯象平底势。并计算得到了在动量中的0^-介子波函数。 关键词：     

旋光纤喇曼放大器中ASE噪音模型及仿真计算

通过分析旋光纤喇曼放大器中信号光、抽运光的非线性薛定谔波动方程及放大自发辐射噪音特性,提出一种能同时在旋光纤喇曼放大器中产生预计波形放大自发辐射噪音,又方便计算的方法.根据放大自发辐射噪音时域特性,建立并在波动方程中加入放大自发辐射非高斯噪音模型.在考虑旋光纤双折射的非线性效应同时,通过分步傅里叶法对波动方程求解,计算了旋光纤喇曼放大器中的放大自发辐射噪音,并与实验结果吻合.     

旋光纤喇曼放大器中ASE噪音模型及仿真计算

通过分析旋光纤喇曼放大器中信号光、抽运光的非线性薛定谔波动方程及放大自发辐射噪音特性,提出一种能同时在旋光纤喇曼放大器中产生预计波形放大自发辐射噪音,又方便计算的方法.根据放大自发辐射噪音时域特性,建立并在波动方程中加入放大自发辐射非高斯噪音模型.在考虑旋光纤双折射的非线性效应同时,通过分步傅里叶法对波动方程求解,计算了旋光纤喇曼放大器中的放大自发辐射噪音,并与实验结果吻合.     

共形协变非线性耦合方程的真空解

我们讨论了标量-旋量共形协变非线性耦合方程的instantonlike和meronlike真空解.     

类Quesne环状球谐振子势场中的赝自旋对称性

提出了一种新的类Quesne环状球谐振子势,应用二分量方法求解1/2-自旋粒子满足的Dirac方程, Dirac哈密顿量由标量和矢量类Quesne环状球谐振子势构成.在Σ=S(r)+V(r)=0的条件下,得到了Dirac旋量波函数下分量的束缚态解和能谱方程, 显示出类Quesne环状球谐振子势场中的赝自旋对称性.讨论了束缚态波函数和能谱方程的有关性质. 关键词： 类Quesne环状球谐振子势 Dirac方程 赝自旋对称性 束缚态     

标架形式的简化旋量体系及其对杨振宁方程的应用

本文给出时空流形的一种简化的旋量描述形式. 特别是证明了在 Newman-Perose 方程中有六个多余的方程. 作为对杨振宁引力场方程的应用, 求得全部O型和一部分N 型“纯粹空间”. 关键词：     

Beltrami-de Sitter时空中标量和旋量粒子的量子理论

参照在Minkowski时空中,从粒子的相对论性经典理论过渡到量子理论,建立标量粒子和旋量粒子的相对论性波动方程的方案,在Beltrami-de Sitter时空中建立了de Sitter不变的标量粒子和旋量粒子的相对论性量子力学的基本方程,它们恰恰分别是Beltrami-de Sitter时空中的Klein-Gordon方程和Dirac方程。在Beltrami-anti de Sitter时空的同时类空超曲面簇上求解了这些方程,得到了分立的本征值和相应的本征函数。 关键词：     

6维纯Kaluza-Klein理论的孤子背景中的费米子场方程

由于偶数维与奇数维时空中的旋量差别很大,在偶数维与奇数维纯Kaluza-Klein理论的孤子背景中的费米子动力学性质有本质差异.本文讨论了费米子在6维纯Kaluza-Klein理论的孤子背景中运动方程导出的一般方法,并以球对称孤子示例.中性无质量费米子方程能完全退耦,并与在Schwarzschild黑洞情形时零四元组形式所得到的方程一致.     

适用于射频加热的迴旋动力方程

参照Chen和Tsai的方法导出了在迴旋频率附近,以三个电场分量为独立场量的线性迴旋动力方程。它适用于研究非均匀等离子体中的射频加热。并给出了该方程在轴对称托卡马克装置中的解。     

一类环状非球谐振子势场中相对论粒子的束缚态解

提出了一种新的环状非球谐振子势, 在标量势与矢量势相等的条件下，给出了其Klein-Gordon方程和Dirac方程的束缚态解. Klein-Gordon方程的θ角向波函数以超几何函数表示，径向波函数可用合流超几何函数或广义拉盖尔多项式表示，能谱方程由径向波函数满足的束缚态边界条件得到. Dirac方程的旋量波函数可用Klein-Gordon方程的解构造. 关键词： 环状非球谐振子势 Klein-Gordon方程 Dirac方程 束缚态     

反向衬底偏压下纳米N沟道金属氧化物半导体场效应晶体管中栅调制界面产生电流特性研究

研究了反向衬底偏压V_B下纳米N沟道金属氧化物半导体场效应晶体管中栅调制界面产生(GMG)电流I_GMG特性, 发现I_GMG曲线的上升沿与下降沿随着|V_B|的增大向右漂移. 基于实验和理论模型分析, 得出了V_B与这种漂移之间的物理作用机制, 漂移现象的产生归因于衬底偏压V_B 调节了表面电势φ_s在栅电压V_G 中的占有比重: |V_B|增大时相同V_G下φ_s会变小, φ_s 的变化继而引发上升沿产生率因子g_r减小以及下降沿产生率因子g_f增大. 进一步发现I_GMG 上升沿与下降沿的最大跨导G_MR, G_MF 在对数坐标系下与V_B成线性关系, 并且随着|V_B|增加而增大. 由于漏电压V_D在I_GMG 上升沿与下降沿中的作用不同, 三种V_D下G_MR-V_B曲线重合而G_MF-V_B曲线则产生差异. 增大V_D 会增强g_f 随V_G的变化, 因此使得给定V_B 下的G_MF变大. 同时这却导致了更大V_D下G_MF-V_B 曲线变化的趋势减缓, 随着V_D从0.2 V变为0.6 V, 曲线的斜率s从0.09减小到0.03. 关键词： 产生电流 表面势 衬底偏压 N沟道金属氧化物半导体场效应晶体管     

计算自旋-s算子幺正演化矩阵ds(t)的新方法及其应用

提出了一种严格求解任意自旋-s算子幺正演化矩阵的方法,该方法不同于群论的方法和直接计算的方法,是一种间接的算法.方法的核心是利用两个系统表示的等价性：即自旋-s算子Hamiltonian量H_s=S_x与Heisenberg XX开链带相互作用J_n=n(N-n)的Hamiltonian量的等价性,由于存在这种等价性,自旋-s算子幺正演化矩阵的计算可通过Heisenberg XX开链中态的演化来实现.采用该方法计算了s=3/2,s=2和s=5/2时对应的幺正演化矩阵.由于初始态|sm〉在算子e^-itS_x下的演化实质上相当于对态|sm〉进行一个绕x轴转角为β＝t的转动,演化矩阵元d^s_m'm(t)=〈sm′|e^-itS_x|sm〉就是转动后的态e^-itS_x|sm〉在|sm′〉态上的投影值,所以在t＝π时刻的演化矩阵刚好对应Heisenberg XX开链上量子态的理想传输. 关键词： s算子')" href="#">自旋-s算子 幺正演化矩阵 量子态传输     

Normal-state resistivity of superconducting Bi1.95Sr1.65La0.4CuO6+δ single crystals

The anisotropy of the normal-state resistivity of a number of superconducting Bi_1.95Sr_1.65La_0.4CuO_6+δ single crystals has been measured by using both a six- and a four-terminal technique. We find that the ab-plane resistivity _ab in general increases almost linearly with temperature (d_ab/dT> 0). the temperature variation of the c-axis resistivity _c, however, is strongly sample dependent. Both metallic-like (d_c/dT> 0) and mixed temperature dependences of _c, including d_c/dT < 0 are observed. The mixed _c(T) data can be well described by fitting to _c(T) = A + BT + C/T, indicating that the temperature dependence of _c(T) is the result of a competition between metallic and non-metallic terms. The temperature T_min at which _c reaches a minimum increases with increasing d_ab/dT, suggesting that the metallic term of _c arises from misaligned Cu---O planes. This is confirmed by an electron-microscope (HRTEM) analysis of the samples. The anisotropy ratio _c/_ab is of the order of 10³ but increases monotonically with decreasing temperature, indicating differences in the scattering processes parallel and perpendicular to the Cu---O plane.     

Reduced s-d model with antiferromagnetically coupled impurity spins

An antiferromagnetic equivalent-neighbour Heisenberg interaction H_i between impurity spins is added to the reduced s-d Hamiltonian H_r previously introduced by simplifying the Kondo s-d exchange Hamiltonian H_K. Asymptotic mean-field theory is developed for H_r + H_i, in the presence and absence of external magnetic field, and applied to (La_1−xCe_x)Al₂ alloys. Specific heat c_i(T) and zero-field susceptibility χ_i(0,T) curves for (La_1−xCe_x)Al₂ are depicted. The coupling constants of H_r + H_i and conduction bandwidth are adjusted so that T_c temperatures for x = 0.2, 0.1 are equal to the experimental values. c_i(T) exhibits a jump at T_c and is decreasing for T < T_c. χ_i(0,T) has a first order pole at T_c which corresponds to the maximum of experimental susceptibility and χ_i(0,0) > 0. These results improve those obtained earlier on the grounds of H_r theory.     

Determination of Hansen Solubility Parameters for the Solid Surface of Cellulose Acetate Butyrate by Inverse Gas Chromatography

The specific retention volumes, , for adsorption of 21 solute probes on the solid surface of cellulose acetate butyrate (CAB) were determined in the temperature range 343.15 to 403.15 K by inverse gas chromatography (IGC). The weight fraction activity coefficients, , and Flory–Huggins interaction parameters, , were evaluated using . Both and values decreased with increase of temperature in all the solutes. Further, the values increased with increase of chain length in n-alkanes, but in the case of alcohols the trend was reversed. values were less than 0.5 in polar solutes and greater than 0.5 in 1-alkanes and alcohols. The Hansen solubility parameters (HSP) were calculated by relating with the cohesive energy of adsorption of the solutes on the surface of CAB. The adsorption model proposed by Snyder and Karger was used to determine the HSP for the CAB. The dispersive, , polar, , and hydrogen bonding components of HSP decreased with increase of temperature and the relative error associated with these parameters increased with increase of temperature. The characterization of the solid surface of CAB in terms of the three solubility parameter components was analyzed and is discussed.     

Natural embedding of group in NMR spin algebras

NMR aspects of finite group natural-embeddings in higher n-fold spin algebras over Hilbert space are considered in the context of icosahedral cage clusters associated with specific ¹¹B borohydride, -deuteride anions for which n = 12. The focus of the discussion is on the abstract and physical models derived from permutation modules in the form of λ ├ n partitions over , where . Hence, the related Kostka expansion coefficients from the pure abstract spin space of mapping and other -combinatorial aspects, including the nature of inner tensor products arising in the high-n limit, are especially pertinent. Further insight into spin cluster NMR problems is provided by studies of -induced algebras derived from the [λ_SA] self-associated irreps. Motivation for the work comes from its potential physical applications for higher-n bi-cluster NMR problems, e.g., in spin dynamics. The representational properties derived are essential in understanding the structure of Liouville space for both SU(2) and higher spin SU(m) clusters. The Hilbert space aspects presented here impact strongly on the somewhat neglected question of the nature of subduction, i.e., involving a finite group naturally embedded in a higher group, within an implicit dual Racah symmetry chain. The essential mappings presented here include both the λ module-onto-{[λ′]} set and the aspects, where the Kostka integers of the former arise naturally in the realization of λ module mappings over .     

The gas-phase electron paramagnetic resonance spectrum of vibrationally excited SO radicals

Gas-phase E.P.R. spectra from the first six vibrational levels in X ³Σ^- SO have been detected and analysed using a Hund's case (b) formalism. The spectra can be fitted using the following molecular constants:

The first and second derivatives of with respect to the normalized internuclear distance ξ were calculated from these constants. A simple analytic formalism is described which enables the variation of with internuclear distance to be separated into contributions from the matrix elements and from the change in energy spacing between interacting states. Both effects are important in the derivatives of , but it is suggested that in SO most of the variation of with rotational and vibrational state is due to the increase in the second-order part of the parameter as the separation between the ground and the dominant perturbing state decreases. This explanation implies that the expression proposed recently by Veseth and Lofthus for the rotational variation of is not accurate, and enables the conflict between the results of their analysis and ab initio calculations to be resolved.     

Entanglement measures of a new type pseudo-pure state in accelerated frames

In this work we analyze the characteristics of quantum entanglement of the Dirac field in noninertial reference frames in the context of a new type pseudo-pure state, which is composed of the Bell states. This will help us to understand the relationship between the relativity and quantum information theory. Some states will be changed from entangled states into separable ones around the critical value F = 1/4, but there is no such a critical value for the variable y related to acceleration a. We find that the negativity N_ABI (ρ^TA_ABI) increases with F but decreases with the variable y, while the variation of the negativity N_BIBII(ρ^TA_ABI) is opposite to that of the negativity N_ABI (ρ^TA_ABI). We also study the von Neumann entropies S(ρ_ABI) and S(ρ_BIBII). We find that the S(ρ_ABI) increases with variable y but S(ρ_BIBII) is independent of it. However, both S(ρ_ABI) and S(ρ_BIBII) first decreases with F and then increases with it. The concurrences C(ρ_ABI) and C(ρ_BIBII) are also discussed. We find that the former decreases with y while the latter increases with y but both of them first increase with F and then decrease with it.     

稠苯芳杂环及其烷基质子化学位移的计算

本文提出了予测稠苯芳杂环及其烷基链上质子化学位移的计算方法。 将稠苯芳杂环化合物用凯库勒式表示,计算式为为需考虑的苯环内的乙烯基效应。σ_mi,ci为各苯环的环流效应。σ_1,Hc为各芳杂环的屏蔽效应,对杂环上质子它就是该单独芳杂环上相应质子的δ值,对苯环上质子要将它分解为各结构因素的效应,即:σ_1,He=(1/2)^d-1δ_x=y(或σ_z)+σ_c-c·σ_m,H. σ_x-y与σ_z为杂原子或其基团的屏蔽效应,σ_c=c为存在于芳杂环中的乙烯基的效应,σ_m,Hc为芳杂环的环流效应,d为对不同质子所考虑的键数。有取代基时需考虑取代基的效应。计算环上烷基质子的公式为:δ=σ_p,CH3+ασ_c,CH3+βσ_t,CH3+σ_l,G σ_l,G为稠苯芳杂环基的某级效应。