Born-Infeld电动力学的U1主丛表述

本文给出了Born-Infeld电动力学的U₁主丛表述,以及检验粒子在Born-Infeld电磁场中的运动方程,检验粒子受到两个力,一个相当于Lorentz力,一个相当于Poincaré压力。     

Born-Infeld电动力学的U_1主丛表述

本文给出了Born-Infeld电动力学的U_1主丛表述,以及检验粒子在Born-Infeld电磁场中的运动方程,检验粒子受到两个力,一个相当于Lorentz力,一个相当于Poincare压力。     

SO5 SU2 SU2 U1 U1及SO5 U1 U1的矢量相干态表示

本文讨论了SO₅ SU₂ SU₂ U₁ U₁及SO₅ U₁ U₁的VCS表示.计算了SO₅ U₂ U₂的约化矩阵元,并利用K矩阵技术确定了SO₅权的多重度.     

SU3 U1 U1的矢量相干态表示

本文讨论了U₃的矢量相干态表示.利用K矩阵技术得到了SU₃ U₁ U₁的正交基矢,从而确定了权的多重度.     

Planck长度和统一引力—电磁的五维U1主丛理论

在统一引力和电磁的五维U₁主丛理论(它可视为Kaluza-Klein理论的一种新表述)中,闭合的且类空的第五维的半径被定出为Plank长度的2α^-1/2倍(α为精细结构常数)。这解释了第五维为什么难以直接观测到。 关键词：     

具有Uqp(U3)Uqp)(U2) Uqp(SO2)对称的双参数形变二维相互作用玻色子模型

构造了具有U_qp(U₃) U_qp(U₂) U_qp(SO₂)对称的双参数qp-形变二维相互作用玻色子模型(IBM),并给出了其能谱和跃迁矩阵元.结果表明,能谱和跃迁矩阵元极其敏感地依赖于第二个形变参数.     

U1–xThxO2混合燃料力学性能的分子动力学模拟

在二氧化铀(UO₂)燃料中掺杂钍(Th)是提高其热稳定性的有效手段.本文利用分子动力学模拟方法,系统研究了温度与掺杂浓度对U_1–xTh_xO₂混合燃料结构稳定性与力学特性的影响.研究发现,沿[001]晶向单轴拉伸可观察到混合燃料由初始面心立方结构的萤石相转化为具有低对称结构的scrutinyite相的特殊相变.混合燃料体系的力学性能强烈依赖于温度与掺杂浓度,弹性模量和断裂应力随温度的升高而减小,断裂应变随温度的升高呈增加趋势.当掺杂浓度小于0.1时,弹性模量呈下降趋势,而掺杂浓度高于0.1时,弹性模量呈增加趋势.断裂应力随掺杂浓度的增加而增加,断裂应变则减小.不同掺杂浓度下混合燃料体系均表现脆性断裂特性,多晶样品中发生脆性沿晶断裂.本文的研究结果可为UO₂燃料的掺杂改性提供力学性能上的理论指导.     

High-resolution study of the ν1/ν5 and 2ν1/ν1+ν5 P-H stretching bands of PH2D

The P-H stretching bands ν₁/ν₅ and 2ν₁/ν₁+ν₅ were recorded using a Bruker 120 HR interferometer with a resolution of 0.0042 and 0.0088 cm⁻¹, respectively, and analyzed. From the fits 33 and 50, respectively, vibrational, rotational, centrifugal distortion, and resonance interaction parameters were obtained. These reproduce 668 and 497 rovibrational energies of the pairs of states ν₁/ν₅ and 2ν₁/ν₁+ν₅ with experimental accuracies, rms=0.00016 and , respectively. “Local mode” behavior of the PH₂ fragment is established and discussed in detail.     

超声冷却SO2( 1A2— 1A1)激光诱导荧光激发谱的转动分析

通过改变SO₂/Ar配比，研究了超声膨胀冷却SO₂( ¹A₂— ¹A₁)系统315—330nm波段振动分辨的激光诱导荧光(LIF)激发谱.获得了属于两个完整带系(1,m,1),(0,n,1)—(0,0,0)的高分辨转动结构谱.其中(ν′₁,ν′₂,ν′₃)=(0,9,1),(0,10,1),(1,7,1),(1 关键词：     

Non-colinear magnetic structure of U3P4 and U3As4

Neutron diffraction experiments have been performed on single crystal samples of U₃P₄ and U₃As₄. The magnetic ordering is found to be a non-collinear three axial structure in which magnetic moments of U⁴⁺ ions are tilted from the [111] axis by an angle of about twenty degrees within (110) planes.     

Evidence for p-f mixing in U3P4 and U3As4 from optical spectroscopy

The near normal incidence reflectivity of the ferromagnets U₃P₄ and U₃As₄ and the isostructural but diamagnetic compounds Th₃P₄ and Th₃As₄ has been measured from 0.03 to 12 eV. Trithorium tetraphosphide and tetraarsenide are shown to be indirect gap semiconductors with gap energies of 0.43 and 0.39 eV, respectively. U₃P₄ and U₃As₄ display similar sets of p→d transitions than the corresponding thorium compounds, however, they are shifted by 0.85 eV to lower photon energies. It is concluded that the uranium compounds are metals due to a merging of the valence p band into the 6d conduction band giving direct experimental evidence for a p-f mixing effect of the same size. Energy level schemes are derived.     

一维H+2与超短强激光脉冲相互作用的经典理论

采用全经典理论研究了一维氢分子离子H⁺₂与超短强激光脉冲相互作用的动力学过程.利用经典统计方法，对激发、离解、电离和离解电离概率的时间演化进行了数值计算.并对计算结果进行了分析. 关键词：     

Magnetic and related properties of U4Rh13Si9 and U4Ir13Si9

The compounds U₄Rh₁₃Si₉ and U₄Ir₁₃Si₉ crystallize with the orthorhombic Er₄Ir₁₃Si₉-type structure that contains three non-equivalent positions of uranium atoms. Their magnetic, electrical transport and thermal properties were studied down to liquid helium temperature in magnetic fields up to 9 T. Both compounds have been found to order antiferromagnetically at low temperatures and to exhibit complex magnetic behavior in the ordered state. Some features characteristic of spin fluctuators (U₄Rh₁₃Si₉) and Kondo lattices (U₄Ir₁₃Si₉) indicate that the two ternaries studied are novel strongly correlated electron systems.     

Electronic properties of Th3As4U3As4 solid solutions

(Th_xU_1?x)₃As₄ solid solutions were obtained in the range 1 ≥ x ≥ 0.85 by the modified Van Arkel method. Their resistivity, thermopower and Hall constant were determined in temperatures 4.2—700 K. The condition of impurity band formation, its merging with conduction band, as well as location of the 5?-electron states have been discussed.     

Magnetic ordering in U4Cu4P7 single crystal

The magnetic ordering in the tetragonal ternary compound U₄Cu₄P₇ has been studied by neutron diffraction. It orders below T_N = 146 K with an antiferromagnetic structure of wave vector k = (001). The magnetic ordering corresponds to a stacking of ferromagnetic (001) uranium planes according to the sequences m₁, m₁, m₂, -m₂, -m₁, -m₁, -m₂, m₂ where m₁ and m₂ represent the magnetic moment, directed along the tetragonal axis of the two uranium sites U(1) (0,0,± z₁) and U(2) (0,0, ± z₂) respectively. The magnetic moments on these two sites have different temperature dependencies as well as well as they reach the different values of 1.1 and 2.2.μ_B for the U(1) and U(2) sites, respectively.     

电-声超导电性的对称理论

利用新的库珀对平均汤近似，导出了电－声系统中声子－库珀对有效作用，证明了声子通过交换虚的库珀对能够产生一个有效的吸引力，导致两动量相反的声子配对并构成稳定的声超导态。发现电子超导态与声子超导态的直积能构成稳定的电－声对称的高温超导基态。在声子－库珀对弱耦合极限下，基态对称破缺成为传统的ＢＣＳ基态。     

电—声超导电性的对称理论

利用新的库珀对平均汤近似，导出了电－声系统中声子－库珀对有效作用，证明了声子通过交换虚的库珀对能够产生一个有效的吸引力，导致两动量相反的声子配对并构成稳定的声超导态。发现电子超导态与声子超导态的直积能构成稳定的电－声对称的高温超导基态。在声子－库珀对弱耦合极限下，基态对称破缺成为传统的ＢＣＳ基态。