Kerr时空赤道面上零测地线方程的严格求解

运用欧拉-拉格朗日方程给出了Kerr时空赤道面上的零测地线方程并求出两个首次积分,结合零测地线所满足的恒等式求得轨道微分方程.通过把被积函数化成部分分式,以及解出被积函数中的一个四次方程并对根进行排序,可把轨道微分方程的解表示成第一类椭圆积分和第三类椭圆积分.     

单胶子交换梯形近似下Bethe-Salpeter方程赝标解

将在动量空间具有积分形式的单胶子交换梯形近似下Bethe-Salpeter方程化为微分方程,求出该方程在四动量为零时的赝标解全部分量,其中第一分量为已知的Goldstein解.     

边界元素法中有关积分的计算方法(Ⅰ)柱状边界条件下对空间立体角积分的计算

利用任意闭合曲面对曲面外任一点所张立体角为零的特点将柱状边界条件下对柱侧面的积分转变为对柱底面的积分,并将其表示成椭圆积分的形式。     

平方律阻力下抛射体运动的一种解法

本文求出了平方律阻力下运动的抛射体,以斜率 f′为参数的非线性微分方程解的积分表示式,讨论了其物理意义,还得到射程的近似解析表达式.     

电磁场存在时宇宙因子不为零的高维类Vaidya时空

本文求出了在宇宙因子不为零时,由高维球对称电磁场和球对称辐射产生的高维类Vaidya时空,并探讨了在高维时空中电磁场能量动量张量的可能表示式。     

边界元素法中有关积分的计算方法(Ⅰ)柱状边界条件下对空间立体角积分的计算

利用任意闭合曲面对曲面外任一点所张立体角为零的特点将柱状边界条件下对柱侧面的积分转变为对柱底面的积分，并将其表示成椭圆积分的形式．     

单胶子交换梯形近似下Bethe－Salpeter方程赝标解

将在动量空间具有积分形式的单胶子交换梯形近似下Ｂｅｔｈｅ－Ｓａｌｐｅｔｅｒ方程化为微分方程，求出该方程在四动量为零时的赝标解全部分量，其中第一分量为已知的Ｇｏｌｄｓｔｅｉｎ解．     

各向异性海森伯自旋链中的高阶孤子

在Holstain-Primakoff表象中研究了各向异性海森伯自旋链模型.在半经典近似条件下,应用相干态求出了明孤子和暗孤子的精确解析解.结果表明:这些解可以用第一类和第三类椭圆积分来表示.内容丰富的暗孤子解是本论文的创新之处.     

物理竞赛中使用积分法求解感应电动势一二

为提升物理竞赛中学生运用积分法解决物理问题的能力, 以感应电动势的求解为例, 提出了用积分法 解题的一般思路. 对于动生电动势, 先寻找动生电动势微元, 再通过对微元积分求解; 对于感生电动势, 在已知感生 电场表达式时, 先求出感生电动势微元, 再对微元积分求解, 也可先利用积分求出通过回路的磁通量, 再根据法拉 第电磁感应定律求解     

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在一种自动补偿零漂积分器的基础上,设计了一种交替式积分器。该积分器把积分时间分割为短时间段,用两个自动补偿零漂积分器交替进行积分,通过累加电路将每段积分信号累加起来得到完整的积分信号。积分器采用CPLD控制时序,在400s内的漂移在10mV左右,能够满足EAST装置实验的需要。     

High resolution photon stimulated desorption spectroscopy of solid nitrogen by resonant N 1s core level excitation

Photon stimulated desorption (PSD) spectra of ions (N⁺, N⁺ ₂, and N²⁺) by N 1s 1 _g and N 1s Rydberg level excitations have been recorded from solid nitrogen for different polarization and detection conditions, and compared with electron yield data. Vibrational fine structure is clearly resolved also in photon stimulated desorption (PSD) spectra; its details depend on layer preparation, but also on the type of signal. Detailed evaluation should allow conclusions on the nature and the dynamics of the process of bond breaking and on the influence of the surroundings on it. Exploiting alignment effects by properly setting polarization and detection angles, symmetries of electronic excited states can be well analysed even for samples consisting of randomly oriented molecules.     

Poincaré invariance for the master field on quantum chromodynamics

I construct allSU(N _c ) gauge fields with the property that Euclidean Poincaré transformations can be compensated by gauge transformations. Linear Abelian components are shown to be forbidden by Lorentz invariance. In a suitable gauge, the result is a set of constant potentials parametrized by Lorentz scalars. These scalars are constrained by the equation of motion atN _c =. A special solution is exhibited.Work supported in part by Schweizerischer Nationalfonds.Invited talk presented at the International Symposium Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 14–19, 1981.I thank H. Leutwyler for drawing my attention to the configuration (35), and M. Lüscher, P. Schwab, P. Sorba and J. Stern for their comments.     

Microstructure of fiber-like SiC/Si3N4 composite particulate

The microstructure of fiber-like SiC/Si₃N₄ composite particulate was investigated using high-resolution transmission electron microscopy techniques. The SiC/Si₃N₄ composite particulate consisted of a-SiC core and a -Si₃N₄ outer shell. Two kinds of composite particulate were distinguished when the observed orientation of the SiC core was <110>. In one type of the SiC/Si₃N₄ composite particulate, a crystal relationship of (111)-SiC | (102) -Si₃N₄ and (111)-SiC (114) -Si₃N₄ was identified; in the other type of the SiC/Si₃N₄ composite particulate, a crystal relationship of (111)-SiC (001) -Si₃N₄, and (111)-SiC (101) -Si₃N₄ was observed.     

Efficient optically pumped NH3 amplifiers in the 10–12 μm region

A pulsed transversely excited CO₂ laser operating on the 9R(30) transition is used to optically pump mixtures of NH₃ in buffer gas. A simple oscillator/amplifier system characterizes the performance of the NH₃ amplifier in the 11 m region. Small-signal gain coefficients of >10%/cm measured on the aQ(3,3) transition at 10.7 m, while pump conversion efficiencies of 50% are shown to occur under saturation conditions. The NH₃ laser system is described by a rate-equation model, which is validated by comparison with experiment over a wide range of operating conditions. Measurements are made for NH₃ concentrations ranging from 0.05 to 0.2%, with Ar, N₂, and He buffer gas pressures from 170 to 700 Torr, and for gas temperatures from 200 to 300 K. Optically pumped NH₃ is shown to be a versatile and efficient system for the amplification of mid-infrared radiation.     

Surviving extrema for the action on the twisted SU(∞) one point lattice

We give a simplified construction of twist eating configurations, based on a theorem due to Frobenius. These configurations are defined through the equation:U U U ⁺ U ⁺ =exp(2in /N) withU SU(N), =1 tod andn an antisymmetric matrix with integer entries. In the (Twisted)-Eguchi-Kawai model they yield extrema some of which survive forN. Comparison is made with the Monte Carlo data of the internal energy in the small coupling region.     

The effects of inkomogeneous center structure on the shape of the ESR spectra of alkali-rich glasses

The paper considers the effect of nonuniform structure in the centers on the ESR spectrum for the case of axial anisotropy in the g factor; it is shown that if (² >² , _¦ >), the model enables one to describe fairly completely the spectrum of a glass containing 33% Na₂O and 67% SiO₂. Good agreement with all experimental evidence is not obtained for potassium silicate glasses.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 6, pp. 86–90, June, 1971.     

A Quantization on Riemann Surfaces with Projective Structure

Let X be a Riemann surface equipped with a projective structure. Let be a square-root of the holomorphic cotangent bundle K _X . Consider the symplectic form on the complement of the zero section of obtained by pulling back the symplectic form on K _X using the map ². We show that this symplectic form admits a natural quantization. This quantization also gives a quantization of the complement of the zero section in K _X equipped with the natural symplectic form.     

The sl2 Loop Algebra Symmetry of the Six-Vertex Model at Roots of Unity

We demonstrate that the six vertex model (XXZ spin chain) with =(q+q^-1)/2 and q^2N=1 has an invariance under the loop algebra of sl₂ which produces a special set of degenerate eigenvalues. For =0 we compute the multiplicity of the degeneracies using Jordan–Wigner techniques.     

Modular properties of the hard hexagon model

The physical quantities (or powers thereof) in the hard-hexagon model that were computed exactly by Baxter are shown to be modular functions with respect to the number-theoretic group ₁[N]. This allows us to determine the analytic structure of, the partition function per site in the thermodynamic limit, and, the density, as functions of the activityz.     

A Mössbauer study of rapidly quenchedCuFe alloys — Antiferromagnetic γ-Fe

A series ofCuFe alloys containing 5, 10 and 16 at% Fe has been prepared using standard ribbon spinning techniques. It is found that samples containing significant fractions ( 5%) of Fe in the form of r-Fe can be obtained readily on quenching from the (r + liquid) phase, applied field spectra (0–5.2 T) on antiferromagnetic r-Fe at 4. 2 K indicate that the anisotropy energy is small and that spins tilt from the minimum energy configuration (spin axes perpendicular to B_appl) for B_appl 2.5T.