通用组合型层析摄影反演

本文采用Ｂｅｓｓｅｌ函数与Ｚｅｒｎｉｃｋｅ函数组合的方式，编制了一通用的Ｔｏｍｏｇｒａｐｈｙ程序。它既可用于撕裂模磁岛结构的研究，又可用于杂质剖面的反演。结果说明，这种组合方式既有Ｂｅｓｓｅｌ函数的优点－在边界无毛齿，又有Ｚｅｒｎｉｃｋｅ函数的优点－在中心反演精度较高。     

离子—原子碰撞中对一种两维积分的解析处理方法

一种两维积分（从离子－原子碰撞中的两中心矩阵元分离得到）通过引入Ｌａｐｌａｃｅ变换而解析地积出，并用变形的Ｂｅｓｓｅｌ函数来表示，传统的Ｆｅｙｎｍａｎ变换对于这种与激发态俘获相关的更一般的积分是非常复杂的。     

离子─原子碰撞中对一种两维积分的解析处理方法

一种两维积分（从离子─原子碰撞中的两中心矩阵元分离得到）通过引入Ｌａｐｌａｃｅ变换而解析地积出，并用变形的Ｂｅｓｓｅｌ函数来表示。传统的Ｆｅｙｎｍａｎ变换对于这种与激发态俘获相关的更一般的积分是非常复杂的。     

Fresnel波带片的衍射场

本文从Ｈｕｙｇｅｎｓ－Ｆｒｅｓｎｅｌ原理的表式出发，用Ｆｏｕｒｉｅｒ－Ｂｅｓｓｅｌ变换讨论Ｆｒｅｓｎｅｌ波带片衍射场的特征，可以很自然地得到波带片的一系列焦点位置，求得焦平面上复振幅及光强的分布     

小角激光背散射研究凝胶溶胀过程结构性质

小角激光背散射研究凝胶溶胀过程结构性质原续波盛京何庆（天津大学材料科学与工程系天津３０００７２）ＴｈｅＳｔｕｄｙｏｎＳｗｅｌｉｎｇＰｒｏｃｅｓｓｏｆＧｌｕｃｏｓｅＳｅｎｓｉｔｉｖｅＣｈｉｔｏｓａｎＧｅｌｓＬｏａｄｅｄＷｉｔｈＥｎｚｙｍｅＢｙＳｍａｌ...     

任意结构阵列宽带恒定束宽波束形成新方法

提出了一种任意结构阵列宽带恒定束宽波束形成的新方法．该方法把任意结构阵列的响应向量表示成以Ｂｅｓｓｅｌ函数为核函数的级数之和,并将高阶项截断,然后把频带内各个频率点上的阵列响应向量转化到参考频率上,从而得到恒定束宽波束形成向量,使得各个频率上的波束和参考波束相同．同时,本文还给出了一种基于自适应处理的参考波束优化方法．结合均匀分布离散国阵所作的计算机仿真验证了本文所提方法的有效性．     

Bessel光束纵向特性及参量的影响

利用数值计算研究了Ｂｅｓｓｅｌ光束的纵向特性及参量对其的影响，发现在光强达到最大值Ⅰｍａｘ后，先迅速衰减但是并不趋于零，而后缓慢减小；光强的衰减速度，决定于β的大小，而光强的振荡性同时与β和Ｒ有关。只有当β→０和Ｒ→∞同时被满足时，才能实现理想无衍射光束。     

PGBs对高能e~＋e~－湮没产生顶夸克对的单圈量子效应

在一代Ｔｅｃｈｎｉｃｏｌｏｒ（ＴＣ）模型中计算了ＰＧＢｓ（ＰｓｅｕｄｏＧｏｌｄｅｎｓｔｏｎｅＢｏｓｏｎｓ）对高能ｅ＋ｅ－→ｔｔ过程的单圈量子效应．给出了重整化的形状因子和矩阵元．计算了ＰＧＢｓ对总截面前后不对称参数ＡＦＢ和左右不对称参数ＡＬＲ的虚贡献，结果表明选取适当的参数值，新物理对以上可测量的贡献最大分别可达：－１２．３％、－３．３％和－１１．７％．在下一代对撞机上这一理论结果能为ＴＣ理论打开实验的窗口．同样的计算表明ＰＧＢｓ对ｅ＋ｅ－→ｂｂ过程的单圈贡献小于－１．０％．     

天然脱氧核糖核酸分子中碱基价键的振动变化

天然脱氧核糖核酸分子中碱基价键的振动变化余多慰，柯惟中（南京师范大学南京２１００９７）ＲａｍａｎＣｈａｒａｃｔｅｒｉｓｔｉｃＡｎａｌｙｓｅｓｏｆＴｈｅＴｗｏＣｏｖａｌｎｅｃｅＢｏｎｄｓｂｙＴｈｅＢａｓｅＳｌｄｅｏｆＧｌｙｃｏｓｉｄｌｃＢｏｎｄｉｎＤＮ...     

改进型Andersson-Braun中子雷姆仪对0.025eV-45.4MeV中子的能量响应

描述了一种适用于高能粒子加速器周围杂散辐射场测量的改进型Ａｎｄｅｒｓｓｏｎ－Ｂｒａｕｎ中子雷姆仪的原理与结构。利用国内外多种类型的中子源装置，进行了中子能量从０．０２５ｅＶ－４５．４ＭｅＶ的注量率能量响应实验，实验表明，这种改进型Ａｎｄｅｒｓｓｏｎ－Ｂｒａｕｎ中子雷姆仪，对能量大于２０ＭｅＶ中子的响应，比普通Ａｎｄｅｒｓｓｏｎ－Ｂｒａｕｎ中子雷姆仪有明显的改善。     

虚阶Bessel函数的计算

给出了计算虚阶Bessel函数及其导数的完整算法。数值结果表明,计算精度可达10位以上有效数字。此外,所给出的逆推法可推广到复阶数的情形。     

The Solution of a New Kind of Integrals of Bessel Functions Used in the Power Calculation

In the evaluation of the power flow in some millimeter RF structures, a new kind of integrals of the type in which _±(kr) denotes arbitrary Bessel functions of real order ±, is met. In order to integrate it, a new transformation of modified Bessel function is build in this paper: then a general integral formula involving the products two terms, each of them can be expressed a sum of any two modified Bessel function, is obtained by means of applying a theorem on calculus to this transformation smartly, Furthermore, making use of the characteristics of modified Bessel function and the definition of Bessel function, the analytical expression of the above integral is derived.     

Internal oscillation of vector solitons and necklace solitons

Internal modes and internal oscillation of vector solitons associated with photoisomerization and necklace solitons in Bessel lattices are researched. While white noise gives rise to the unsmoothness of the vector solitons, the perturbation of internal modes results in the long-distance quasi-periodic oscillation of soliton shape. Internal modes of two-dimensional necklace solitons in Bessel lattices have both real and imaginary parts, which is different with the internal modes of one-dimensional solitons which have only real part.     

Necklace solitons in Bessel photonic lattice: Stability and internal oscillation

Stability, internal modes and internal oscillation of 12-pearled necklace solitons in photorefractive crystal with imprinted Bessel photonic lattices are investigated. It is shown that the imaginary parts of internal modes are negligible comparing with real parts. The stable solitons perform long-distance and quasi-periodic oscillation of intensity and shape under the perturbation of internal modes.     

Asymptotic Properties of Solvable $\mathcal{PT}$-Symmetric Potentials

The asymptotic region of potentials has strong impact on their general properties. This problem is especially interesting for PT\mathcal{PT}-symmetric potentials, the real and imaginary components of which allow for a wider variety of asymptotic properties than in the case of purely real potentials. We consider exactly solvable potentials defined on an infinite domain and investigate their scattering and bound states with special attention to the boundary conditions determined by the asymptotic regions. The examples include potentials with asymptotically vanishing and non-vanishing real and imaginary potential components (Scarf II, Rosen-Morse II, Coulomb). We also compare the results with the asymptotic properties of some exactly non-solvable PT\mathcal{PT}-symmetric potentials. These studies might be relevant to the experimental realization of PT\mathcal{PT}-symmetric systems.     

Choice of optimal conditions in electromagnetic analysis

A theoretical study is presented for alternating magnetic fields in a sphere and a long cylinder; this is extended to frequencies such that differences in diameter and surface conductivity are not distinguished in Förster's method. Optimal conditions for structural testing of the entire cross-section are found to occur in the audiofrequency range. Tables are given for the second derivatives of the real and imaginary components of the Bessel and McDonald functions.     

Stochastic resonance in a gain--noise model of a single-mode laser driven by pump noise and quantum noise with cross-correlation between real and imaginary parts under direct signal modulation

Stochastic resonance (SR) is studied in a gain--noise model of a single-mode laser driven by a coloured pump noise and a quantum noise with cross-correlation between real and imaginary parts under a direct signal modulation. By using a linear approximation method, we find that the SR appears during the variation of signal-to-noise ratio (SNR) separately with the pump noise self-correlation time \tau , the noise correlation coefficient between the real part and the imaginary part of the quantum noise \lambda_q , the attenuation coefficient \gamma and the deterministic steady-state intensity I_0 . In addition, it is found that the SR can be characterized not only by the dependence of SNR on the noise variables of \tau and \lambda_q, but also by the dependence of SNR on the laser system variables of \gamma and I₀. Thus our investigation extends the characteristic quantity of SR proposed before.     

一种含时贝塞尔光束的理论性质研究

本文从理论角度提出了一种"含时贝塞尔光束"的概念.在非傍轴和非时谐条件下,直接从麦克斯韦方程出发,借鉴半贝塞尔光束的处理方法,同时引入第四维虚数坐标,由此获得了完整的"含时贝塞尔光束"的解析表达式.并从无衍射性质和时空特性两个方面对其进行了探讨和研究,发现该光束具有如下性质:符合贝塞尔光束类型的无衍射特征;在时空双曲线上强度保持不变;光波时空特性的临界条件类似于相对论中的光锥."含时贝塞尔光束"的概念为无衍射自加速光束的研究开拓了新的思路和方向.     

Calculations of the Mie scattering coefficients for multilayered particles with large size parameters

The calculation procedure for the scattering coefficients appearing in the Mie theory is discussed for a case of multilayered particles with a large size parameter. There are two different aspects to the problem. The first aspect concerns a case where the imaginary part of the size parameters remains small. Shown here is the possibility for avoiding the canonical recommendations which prescribe using both upward and downward recursions for different types of Bessel functions. We have justified the procedure based on the upward recursions only where results are as stable as those in the canonical one. The second aspect concerns the case with a large imaginary part of the size parameter. The calculation procedure for a multilayered particle fails in such a case because of 0/0-type uncertainty. However, this problem can be overcome by using the proper asymptotic relations at crucial points. The numerical results are demonstrated for spherical and cylindrical multilayered particles.     

Stochastic Resonance in a Single-Mode Laser Driven by Pump Noise and Quantum Noise with Cross-Correlated Real and Imaginary Parts

We present an analytic investigation of the signal-to-noise ratio (SNR) by studying a signal modulated model of a single-mode laser system driven by pump noise and quantum noise with correlated real and imaginary parts,and find there is a maximum in the curve of the dependence of SNR upon the cross-correlation coefficient λq between the real part and the imaginary part, i.e., stochastic resonance appears in the SNR vs. λq curve. Moreover, when the SNR is at the maximum, the cross-correlation coefficient λq = O, which is coincidentally at the minimum of the mean normalized intensity fluctuation. The influences on stochastic resonance by the intensities of the pump and the quantum noise, the amplitude of the modulation signal, and the net gain of the laser are also studied. Furthermore, in order to ensure that the results obtained in this paper is reliable, the valid range for the linear approximation method is discussed.