用改进的格点哈密顿量计算2+1维U(1)规范场真空波函数

从格点U(I)规范场论中改进的哈密顿量出发,推导出截断本征方程.并对2十1维外1)规范场真空波函数进行数值计算,验证了理论的预言:对格点哈密顿量进行改进能使真空波函数的标度行为明显地改善.     

3维U(1)改进格点规范理论中胶球质量和胶球波函数

用改进的格点规范场哈密顿量和截断本征方程法计算2+1维U(1)规范场的胶球质量(质量隙)和胶球波函数,结果显示出较好的标度行为.     

2+1维U(1)改进格点规范理论中0++胶球波函数的三阶结果

用改进的格点规范场哈密顿量和截断本征方程法计算2+1维U(1)规范场的0++胶球波函数，三阶结果比二阶结果的标度行为有了较大的改善.     

2+1维SU(2)格点规范场真空态的研究

对2+1维SU(2)格点规范场论真空态进行研究,推导出连续极限下真空波函数中参数μ₀和μ₂的普适表达式.并用基于改进的哈密顿量的截断本征方程进行数值计算,结果在深度弱耦合区内显示出良好的标度行为.     

2+1维格点QCD真空波函数的计算

用改进的格点哈密顿量和截断本征方程法计算2+1维QCD真空波函数,结果显示出良好的标度行为.     

格点(1+1)维QCD中<ψψ>的变分研究

改进的哈密顿量对格点(1+1)维QCD中Wilson费米子真空凝聚<ψψ>做变分研究.结果不但与连续理论的预言值一致,而且几乎不依赖于Wilson参数r.对于改进的哈密顿量而言,么正变换算符中的三链项对<ψψ>的贡献是很重要的.     

用改进的哈密顿量计算Wilson费米子真空凝聚

用改进的哈密顿量和变分法计算格点(1+1)维QED(Schwinger模型)中Wilson费米子真空凝聚<ψψ>，结果(同使用未改进的哈密顿量的计算结果相比较)与Wilson参数r的依赖关系明显地减小了.     

3+1维格点规范理论0++和0－－胶球质量

在哈密顿形式下,把无规相近似方法从(2+1)维SU(2)格点规范场推广到3+1维SU(3)格点规范场,利用这种改进的耦合集团展开方法计算3+1维SU(3)的真空波函数和0^－－与0⁺⁺胶球质量之比,得到令人满意的结果:γ=m(0－－)m(0++)=1.8578±0.0506.     

格点(1 1)维QCD中<ψ>的变分研究

改进的哈密顿量对格点（1＋1）维QCD中Wilson费米子真空凝聚<ψψ>做变分研究．结果不但与连续理论的预言值一致,而且几乎不依赖于Wilson参数r．对于改进的哈密顿量而言,么正变换算符中的三链项对<ψψ>的贡献是很重要的     

2+1维SU(2)规范模型的弦张力

本文对两种具有严格基态解的格点哈密顿量,采用变分法计算了2+1维SU(2)规范模型的弦张力.     

Surface diffusion of dysprosium on the W(1 1 1) facet

Diffusion of dysprosium on the (1 1 1) facet of a tungsten micromonocrystal was investigated by means of spectral analysis of field emission current fluctuations. The experimental spectral density functions of the current fluctuations were analysed by using Gesley and Swanson’s theoretical spectral density function, which enables to determine the surface diffusion coefficient D for dysprosium. Derived from the temperature dependence of D, the diffusion activation energy E is presented for some Dy coverages θ_(1 1 1). In the temperature range 400–600 K, the E first drops from 1.25 eV per atom at θ₍₁₁₁₎≈0.25 ML to 0.48 eV per atom at θ₍₁₁₁₎≈1 ML (corresponding to the minimum of the work function of the system), then increases to 1.03 eV per atom at θ₍₁₁₁₎≈1.3 ML. The results are discussed from the aspects of the substrate structure and interaction in the adsorbed layer.     

Spectroscopy of the electron subbands on (1 1 1)-Si

We present measurements of infrared inter-subband absorption for electron subbands on (1 1 1)-Si for densities N_s up to ～ 10¹³ cm^?2 at 4.2 K for both parallel- and perpendicular-excitation geometries. Contrary to previously published work the depolarization shift is identified as a sizeable splitting of the resonance energies E^⊥₀₁ and E^z.dfnc;₀₁. The comparison with a recent calculations is given.     

Reduction of the semisimple 1:1 resonance

The method of “averaging” is often used in Hamiltonian systems of two degrees of freedom to find periodic orbits. Such periodic orbits can be reconstructed from the critical points of an associated “reduced” Hamiltonian on a “reduced space”. This paper details the construction of the reduced space and the reduced Hamiltonian for the semisimple 1:1 resonance case. The reduced space will be a 2-sphere in R³, and the reduced differential equations will be Euler's equations restricted to this sphere. The orbit projection from the energy surface in phase space to this sphere will be the Hopf map. The results of the paper are related to problems in physics on “degeneracies” due to symmetries of classical two-dimensional harmonic oscillators and their quantum analogues for the hydrogen atom.     

Measuring the Au(1 1 1) surface state at the solid–liquid interface

We present the first direct observation of an occupied noble metal surface state at the metal/liquid interface. The Au(1 1 1) Shockley-like surface state was measured by scanning tunneling spectroscopy (STS) at the Au(1 1 1)/n-tetradecane interface. These results show that the surface state of gold survives in a liquid environment, and can be probed by STS. More generally it indicates that STS can be used to study electronic properties of surfaces at the solid/liquid interface, and that spectra can be directly compared to measurements and calculations of a surface’s electronic structure in ultra-high vacuum.     

1-cocycles on the group of contactomorphisms on the supercircles S1|1 and S1|2 generalizing the Schwarzian derivative

We give an explicit construction of the $1$-cocycles of the group of contactomorphisms on the supercircle $S^{1|m}$ for $m=1,2$, with coefficients in the space of differential operators acting on $S^{1|m}$-tensor densities. We show that they satisfy properties similar to those of the super-Schwarzian derivative.     

Natural radiative lifetimes in the1 P 1 and1 F 3 sequences of Sr I

We have measured radiative lifetimes in the 5s n p ¹ P ₁ (n=5–29) and 5s n f ¹ F ₃ (n=4–11) Rydberg series in neutral strontium. The measurements were performed with single-step laser excitation starting from the ground state or from a metastable state populated by collisions. The decay photons were detected using delayed coincidence technique or a transient recorder. The presence of configuration interaction in the 5s n p ¹ P ₁ series can be observed aroundn=8. The perturbation in the 5s n f ¹ F ₃ series is not reflected in the behaviour of the lifetime values.     

Transition probabilities of the X1Σ+, A1Π, B1Δ, C1Σ+, and D1Π states of the AlO+ cation

ABSTRACT

This study computes the potential energy curves of the X¹Σ⁺, A¹Π, B¹Δ, C¹Σ⁺, and D¹Π states of AlO⁺ cation and the transition dipole moments between them. The orders of the rotationless radiative lifetimes are 10–100?μs for the A¹Π state, 1–1000?ms for the B¹Δ state, 10?ns for the first well and 100?ns for the second well of the C¹Σ⁺ state, and 1?μs for the D¹Π state. Emissions of the B¹Δ–A¹Π and D¹Π–C¹Σ⁺ systems are so weak that they are hardly measured via spectroscopy, the emissions of the C¹Σ⁺–X¹Σ⁺, C¹Σ⁺–A¹Π, and D¹Π–X¹Σ⁺ systems are so strong that they can be detected readily, and emissions of the A¹Π–X¹Σ⁺ and D¹Π–A¹Π systems can be observed through spectroscopy only by a significant effort. There is a strong great similarity between spontaneous emissions of the A¹Π–X¹Σ⁺ system of the AlO⁺ cation and the A²Π–X²Σ⁺ system of the AlO radical. The emissions of the A²Π–X²Σ⁺ system of the AlO radical have been measured in outer space Therefore, it is highly possible that the emissions of the A¹Π–X¹Σ⁺ system of the AlO⁺ cation can be detected in the astrophysical media.     

1 states and the 1f-2p shell model

The observed 1⁺ cross sections from (³He, p) reactions on even Ca, Ti, Cr and Fe targets are analyzed in terms of an approximate sum rule. It is shown that the summed 1⁺ cross sections in a qualitative way depend on the proton and neutron number of the target as predicted from the shell model.     

Levelcrossing experiments in the first excited1 P 1 states of the alkaline earths

The hyperfine structure of the lowest¹P₁ state of²⁵Mg,⁴³Ca,⁸⁷Sr,¹³⁵Ba and¹³⁷Ba have been measured by the level-crossing and anticrossing technique. The magnetic dipole and electric quadrupole coupling constants determined by these measurements are²⁵Mg(3s3p¹P₁):A=? 7.7(5) MHz; 16 MHz>B>0 MHz,⁴³Ca(4s4p¹P₁):A=? 15.3(4) MHz; ¦B¦<12 MHz,⁸⁷Sr (5s5p¹P₁:A=? 3.4(4) MHz;B=39(4) MHz,¹³⁵Ba(6s6p¹P₁):A=? 97.5(1.0) MHz;B=31(9)MHz,¹³⁷Ba(6s6p¹P₁):A=?109.2(1.2) MHz;B=51(12)MHz. The results have been compared with the predictions of the Breit-Wills theory of the two-electron hyperfine structure using the experimental data on the³P states. Large discrepancies have been observed which are due to different radial wave functions of thes andp electron in the triplet and singlet system. This effect has been taken into account by fitting the data with the aid of two additional parameters. That this procedure is justified is shown by an analysis of the fine structure splitting, the life times, and the isotopic shifts in thesp configurations of group II elements.     

Theoretical study on the interaction of heptafluoro-iso-butyronitrile decomposition products with Al (1 1 1)

Seeking environmentally friendly gas-insulated medium has become a research hotspot in recent years. At present, C₃F₇CN (Heptafluoro-iso-butyronitrile) is considered to be a potential SF₆ environment-friendly alternative gas and some achievements have been made in the study of its insulation and decomposition characteristics, but there are few reports on the compatibility between its characteristic decomposition products and materials. The investigation of compatibility between gas-insulated medium and material is an important part of evaluating its comprehensive performance. In this paper, we investigated the interaction between C₂F₅CN, CF₃CN, COF₂ and CF₄ with the aluminium widely used in electrical equipment. It was found that the interaction between C₂F₅CN, CF₃CN and Al (1 1 1) surface is strong. There are obvious charge transfer and electron orbital overlap between the C atom, N atom in CN group and Al (1 1 1). The interaction between COF₂, CF₄ and Al (1 1 1) surface is weak and van der Waal’s forces play the major role. Relevant results reveal the characteristics of C₃F₇CN decomposition products and provide theoretical guidance for evaluating the material compatibility between C₃F₇CN decomposition products and aluminium.